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Abstract Background Interatrial right-to-left shunt flow through a patent foramen ovale (PFO) can be caused by changes in heart position for anastomosis during off-pump coronary artery bypass (OPCAB). We herein present a case in which the direction of PFO shunt flow changed with heart position during OPCAB and the ventilation settings after sternal closure. Case presentation A 66-year-old man with interstitial pneumonia underwent OPCAB. Preoperative transesophageal echocardiography revealed right-to-left shunt flow through a PFO induced by the Valsalva maneuver. During OPCAB, heart displacement resulted in right-to-left shunting and acute hypoxemia, which quickly improved with increase of inspired oxygen fraction. After chest closure, bidirectional shunt flow developed under increased airway pressure. Conclusions Vigilant intraoperative monitoring with TEE and postoperative airway pressure management are important to address shunt flow and hypoxemia due to PFO.

Muammar M Kabir,1,2,&ast; Atousa Assadi,1– 3,&ast; Shumit Saha,4 Bojan Gavrilovic,1 Kaiyin Zhu,1 Susanna Mak,5 Azadeh Yadollahi1,2 1KITE-Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada; 2Institute for Biomedical Engineering, University of Toronto, Toronto, ON, Canada; 3Temerty Center for AI Research and Education in Medicine, University of Toronto, Toronto, ON, Canada; 4Department of Biomedical Data Science, School of Applied Computational Sciences (SACS), Meharry Medical College, Nashville, TN, USA; 5Department of Medicine, Division of Cardiology, University of Toronto, Toronto, ON, Canada&ast;These authors contributed equally to this workCorrespondence: Azadeh Yadollahi, KITE-Toronto Rehabilitation Institute, University Health Network, Room 12-106, 550 University Ave., Toronto, ON, M5G 2A2, Canada, Tel +1 416 597 3422 x 7936, Fax +1 416 597 8959, Email azadeh.yadollahi@uhn.caPurpose: Cardiovascular disorders are the leading cause of mortality worldwide with obstructive sleep apnea (OSA) as the independent risk factor. Heart sounds are strong modalities to obtain clinically relevant information regarding the functioning of the heart valves and blood flow. The objective of this study was to use a small wearable device to record and investigate the changes in heart sounds during respiratory events (reduction and cessation of breathings) and their association with oxyhemoglobin desaturation (hypoxemia).Patients and Methods: Sleep assessment and tracheal respiratory and heart sounds were recorded simultaneously from 58 individuals who were suspected of having OSA. Sleep assessment was performed using in-laboratory polysomnography. Tracheal respiratory and heart sounds were recorded over the suprasternal notch using a small device with embedded microphone and accelerometer called the Patch. Heart sounds were extracted from bandpass filtered tracheal sounds using smoothed Hilbert envelope on decomposed signal. For each individual, data from 20 obstructive events during Non-Rapid Eye Movement stage-2 of sleep were randomly selected for analysis.Results: A significant increase in heart sounds’ intensities from before to after the termination of respiratory events was observed. Also, there was a significant positive correlation between the magnitude of hypoxemia and the increase in heart sounds’ intensities (r> 0.82, p< 0.001). In addition, the changes in heart sounds were significantly correlated with heart rate and blood pressure.Conclusion: Our results indicate that heart sound analysis can be used as an alternative modality for assessing the cardiovascular burden of sleep apnea, which may indicate the risk of cardiovascular disorders. Keywords: heart sounds, obstructive sleep apnea, sympathetic nervous activity, hypoxemia, blood pressure

Abstract Background Pulse oximetry is a standart of anesthesia for perioperative monitoring. Due to the principles of Hb oxygen dissociation curve, peripheral oxygen saturation has an approximate sensitivity and specificity of 90% for the detection of hypoxemia. Objectives The primary outcome of the study was to evaluate ORiⓇ as an early parameter to determine hypoxia in morbidly obese patients. The secondary outcome was to compare the effectiveness of ORiⓇ with SpO2 in non-obese patients. Design Prospective, observational study. Setting Department of elective operating room at tertiary hospital. Patients and methods Observational study included written informed consent from 51 patients with 19 40 kg/m2 undergoing an elective surgery requiring tracheal intubation. In addition to standard monitors, an ORi sensor was placed and baseline values were recorded. The patients were preoxygenated until end tidal expiratory oxygen concentration is reached to 90%. After anesthesia induction and tracheal intubation, the breathing circuit was not connected tracheal tube until the SpO2 decreased to 95%. Shapiro-Wilk, Pearson Chi-square, t-test, and Mann Whitney U test were used for the study. Main outcome measures Times of tolerable apnea, ORiⓇ and SpO2 values at the end of preoxygenation, beginning of intubation, beginning of the ORi alarm, when SpO2 reached 95%, and when ORi reaches a plateau. Sample size 102 patients. Results The alert period: time to reach ORiⓇ from 0.24 to a value of 95% SpO2 was observed as 32 s in morbidly obese patients and 94 s in patients with a normal body mass index. The SpO2 alert period was determined as time difference between 97% and 95% SpO2. The data were recorded as 15 s and 36 s, respectively. It was observed that tolerable apnea, ORiⓇ, SpO2 and added alert times were longer in patients with normal BMI compared to morbidly obese patients. Conclusions As a result, ORiⓇ can provide an early warning to prevent unexpected hypoxia before saturation begins to decrease in morbidly obese patients. Limitations Inability to perform arterial blood gas sampling in the time periods when we looked at the parameters to determine the relationship between ORiⓇ and PaO2. Clinical trials. gov identifier NCT05480748 registered 2022-07-29.

The article is devoted to the mystical component of the religious practice of the upper Vychegdas Orthodox community of bursyylisy 'singers of good' (Komi Republic). The community was organized by Stepan Ermolin, a native of the Myeldinsky pogost, a translator of sacred texts from Church Slavonic and Russian into the Komi language, in the 1900s. Religious services of the "singers of good" were held in the Komi-Zyryan language, in continuation of the traditions established in the 14th century by the First Baptist of the Vychegdas Perm people (ancestors of the Komi-Zyrians) St. Stephen, the first bishop of Perm. The current of bursylisy spread along the upper Vychegda, communities arose in the villages of Myeldino, Usty-Nem, Pozheg, Skorodum, Vylygort, Bogorodsk. For some community members, spirit-vision or "communication with the saints / the Mother of God / Christ" in a state of trance was typical. The article attempts to reconstruct the conditions, ways and methods of achieving altered states of consciousness by spirit-seers, and also explains the reasons for the sharp decline of this phenomenon in the 1950s.

Abstract Introduction Hypoxemia is a common complication of childhood respiratory tract infections and non-respiratory infections. Hypoxemic children have a five-fold increased risk of death compared to children without hypoxemia. In addition, there is limited evidence about hypoxemia and clinical predictors in Ethiopia. Therefore, this study was conducted to assess the prevalence and clinical predictors of hypoxemia among children with respiratory distress admitted to the University of Gondar Comprehensive Specialized Hospital. Methods An institutional-based cross-sectional study was conducted from December 2020 to May 2021 in northwest Ethiopia. A total of 399 study participants were selected using systematic random sampling. The oxygen saturation of the child was measured using Masimo rad-5 pulse oximetry. SPSS version 21 software was used for statistical analysis. Result In this study, the prevalence of hypoxemia among children with respiratory distress was 63.5%. The clinical signs and symptoms significantly associated with hypoxemia were: head-nodding (AOR: 4.1, 95% CI: 1.81–9.28) and chest indrawing (AOR: 3.08, 95% CI: 1.32–7.16) which were considered statistically the risk factors for hypoxemia while inability to feed (AOR: 0.13, 95% CI: 0.02–0.77) was the protective factor for hypoxemia. The most sensitive predictors of hypoxemia were fast breathing with sensitivity (98.4%), nasal flaring (100.0%), chest indrawing (83.6%), and intercostal retraction (93.1%). The best specific predictors of hypoxemia were breathing difficulty with specificity (79.4%), inability to feed (100.0%), wheezing (83.0%), cyanosis (98.6%), impaired consciousness (94.2%), head-nodding (88.7%), and supra-sternal retraction (96.5%). Conclusion and recommendation The prevalence of hypoxemia among children was high. The predictors of hypoxemia were the inability to feed, head nodding, and chest indrawing. It is recommended that the health care settings provide immediate care for the children with an inability to feed, head nodding, and chest indrawing. The policymakers better to focus on preventive strategies, particularly those with the most specific clinical predictors.

Abstract Introduction Sleep-disordered breathing (SDB) is a major comorbidity in idiopathic pulmonary fibrosis (IPF) and is associated with a poor outcome. There is a lack of knowledge regarding the impact of SDB treatment on IPF. We assessed at one year: (1) the effect of CPAP and/or nocturnal oxygen therapy on IPF regarding lung function, blood mediators, and quality of life; (2) adherence to SDB treatment and SDB changes. Methodology This is a prospective study of consecutive newly diagnosed IPF patients initiating anti-fibrotic treatment. Lung function, polysomnography, blood tests and quality of life questionnaires were performed at inclusion and after one year. Patients were classified as obstructive sleep apnoea (OSA), central sleep apnoea (CSA), and sleep-sustained hypoxemia (SSH). SDB therapy (CPAP and/or nocturnal oxygen therapy) was initiated if needed. Results Fifty patients were enrolled (36% had OSA, 22% CSA, and 12% SSH). CPAP was started in 54% of patients and nocturnal oxygen therapy in 16%. At one-year, polysomnography found improved parameters, though 17% of patients had to add nocturnal oxygen therapy or CPAP, while 33% presented SDB onset at this second polysomnography. CPAP compliance at one year was 6.74 h/night (SD 0.74). After one year, matrix metalloproteinase-1 decreased in OSA and CSA (p = 0.029; p = 0.027), C-reactive protein in OSA (p = 0.045), and surfactant protein D in CSA group (p = 0.074). There was no significant change in lung function. Conclusions Treatment of SBD with CPAP and NOT can be well tolerated with a high compliance. IPF patients may exhibit SDB progression and require periodic re-assessment. Further studies to evaluate the impact of SDB treatment on lung function and serological mediators are needed.

Abstract The decision to intubate a patient with acute hypoxemic respiratory failure who is not in apparent respiratory distress is one of the most difficult clinical decisions faced by intensivists. A conservative approach exposes patients to the dangers of hypoxemia, while a liberal approach exposes them to the dangers of inserting an endotracheal tube and invasive mechanical ventilation. To assist intensivists in this decision, investigators have used various thresholds of peripheral or arterial oxygen saturation, partial pressure of oxygen, partial pressure of oxygen-to-fraction of inspired oxygen ratio, and arterial oxygen content. In this review we will discuss how each of these oxygenation indices provides inaccurate information about the volume of oxygen transported in the arterial blood (convective oxygen delivery) or the pressure gradient driving oxygen from the capillaries to the cells (diffusive oxygen delivery). The decision to intubate hypoxemic patients is further complicated by our nescience of the critical point below which global and cerebral oxygen supply become delivery-dependent in the individual patient. Accordingly, intubation requires a nuanced understanding of oxygenation indexes. In this review, we will also discuss our approach to intubation based on clinical observations and physiologic principles. Specifically, we consider intubation when hypoxemic patients, who are neither in apparent respiratory distress nor in shock, become cognitively impaired suggesting emergent cerebral hypoxia. When deciding to intubate, we also consider additional factors including estimates of cardiac function, peripheral perfusion, arterial oxygen content and its determinants. It is not possible, however, to pick an oxygenation breakpoint below which the benefits of mechanical ventilation decidedly outweigh its hazards. It is futile to imagine that decision making about instituting mechanical ventilation in an individual patient can be condensed into an algorithm with absolute numbers at each nodal point. In sum, an algorithm cannot replace the presence of a physician well skilled in the art of clinical evaluation who has a deep understanding of pathophysiologic principles.

Pulmonary arteriovenous malformations (PAVMs) are direct pulmonary artery-to-vein connections without pulmonary capillaries that result in intrapulmonary right-to-left blood shunts. Although most patients with PAVMs may be entirely asymptomatic, PAVMs can induce a series of complications involving the neurological, cardiovascular, and respiratory systems that can lead to catastrophic and often fatal clinical sequelae. In this study we review the available literature and summarize the reported PAVM-related complications among patients with PAVMs. The reviewed studies included observational studies, case studies, prospective studies, and cohort studies, and we provide an overview of PAVM-related neurological and cardiopulmonary manifestations, including stroke, cerebral abscess, transient ischemic attack, cerebral hemorrhage, migraine, seizure, dizziness, cardiac failure, arrhythmia, myocardial infarction, cough, hypoxemia, dyspnea, respiratory failure, hemoptysis, and hemothorax. Identifying and treating PAVMs before the presentation of major complication is important because this can prevent the occurrence of complications and can result in better outcomes. PAVM patients should thus be better evaluated and managed by a multidisciplinary team because they may be in a treatable phase prior to their condition becoming life-threatening.

BackgroundThe aim of this study is the evaluation of a closed-loop oxygen control system in pediatric patients undergoing invasive mechanical ventilation (IMV).MethodsCross-over, multicenter, randomized, single-blind clinical trial. Patients between the ages of 1 month and 18 years who were undergoing IMV therapy for acute hypoxemic respiratory failure (AHRF) were assigned at random to either begin with a 2-hour period of closed-loop oxygen control or manual oxygen titrations. By using closed-loop oxygen control, the patients' SpO2 levels were maintained within a predetermined target range by the automated adjustment of the FiO2. During the manual oxygen titration phase of the trial, healthcare professionals at the bedside made manual changes to the FiO2, while maintaining the same target range for SpO2. Following either period, the patient transitioned to the alternative therapy. The outcomes were the percentage of time spent in predefined SpO2 ranges ±2% (primary), FiO2, total oxygen use, and the number of manual adjustments.FindingsThe median age of included 33 patients was 17 (13–55.5) months. In contrast to manual oxygen titrations, patients spent a greater proportion of time within a predefined optimal SpO2 range when the closed-loop oxygen controller was enabled (95.7% [IQR 92.1–100%] vs. 65.6% [IQR 41.6–82.5%]), mean difference 33.4% [95%–CI 24.5–42%]; P < 0.001). Median FiO2 was lower (32.1% [IQR 23.9–54.1%] vs. 40.6% [IQR 31.1–62.8%]; P < 0.001) similar to total oxygen use (19.8 L/h [IQR 4.6–64.8] vs. 39.4 L/h [IQR 16.8–79]; P < 0.001); however, median SpO2/FiO2 was higher (329.4 [IQR 180–411.1] vs. 246.7 [IQR 151.1–320.5]; P < 0.001) with closed–loop oxygen control. With closed–loop oxygen control, the median number of manual adjustments reduced (0.0 [IQR 0.0–0.0] vs. 1 [IQR 0.0–2.2]; P < 0.001).ConclusionClosed-loop oxygen control enhances oxygen therapy in pediatric patients undergoing IMV for AHRF, potentially leading to more efficient utilization of oxygen. This technology also decreases the necessity for manual adjustments, which could reduce the workloads of healthcare providers.Clinical Trial RegistrationThis research has been submitted to ClinicalTrials.gov (NCT05714527).

ABSTRACT Background: Hepatopulmonary syndrome (HPS) is characterized by the triad of abnormal arterial oxygenation caused by intrapulmonary vascular dilatations (IPVD) in the setting of advanced liver disease or portal hypertension, impacting the patient’s quality of life and survival. There are still many gaps in the literature on this topic, especially in pediatrics, with practices frequently based on extrapolation of data obtained from adults. Objective: Provide a synthesis of the current knowledge about HPS in children. Methods: The research was carried out through narrative review. The databases used for the search include Medline, Embase, Elsevier, Lilacs and Scielo. The keywords used were “hepatopulmonary syndrome” AND child, children, infant, preschool, pediatric. Results: In cirrhotic children, the prevalence of HPS can reach up to 42.5%, and it is even more common in those whose underlying condition is biliary atresia, reaching up to 63%. Screening with pulse oximetry (O2 saturation

Abstract Background Hypoxemia can occur in people at ultra-high altitude (above 3500 m) even at rest, and patients undergoing gastroscopy under general anesthesia have higher risk of hypoxemia. Supplementary oxygen via standard nasal cannula (SNC) is the standard of care for most patients who undergo gastroscopy under general anesthesia, which provides oxygen flow up to 15 L/min. High-flow nasal cannula (HFNC) could deliver oxygen at a rate up to 60 L/min, which is recommended by the American Society of Anesthesiologists Practice Guidelines. We speculated that the benefit with HFNC is more prominent in high-altitude areas, and aimed to compare the incidence of hypoxemia during gastroscopy under general anesthesia at ultra-high altitude with oxygen supply via either HFNC or SNC. Methods The trial was registered at at Chinese Clinical Trial Registry (ChiCTR2100045513; date of registration on 18/04/2021). Adult patients undergoing gastroscopy with anesthesia (estimated duration of anesthesia at ≥ 15 min) were randomized at a 1:1 ratio to receive HFNC oxygen or SNC oxygen. The primary outcome was hypoxemia (SpO2

Abstract Background Hypoxemia represents the most prevalent adverse event during flexible bronchoscopy procedures aimed at foreign body retrieval in pediatric patients; if not expeditiously managed, it carries the potential for cardiac or respiratory arrest. The specific risk factors contributing to the occurrence of hypoxemia during foreign body FB removal via bronchoscopy have yet to be definitively established. Methods This retrospective study included a cohort of 266 pediatric subjects from January 1, 2015, to December 31, 2022, who underwent flexible bronchoscopy for the purpose of FB extraction. In this cohort, the supraglottic airway was used to connect the anesthesia apparatus during the removal procedure. Results In total, 45 of the pediatric patients (16.9%) experienced episodes of hypoxemia during the FB removal procedure. Multivariate analysis revealed that the following factors were significantly associated with the occurrence of hypoxemia: an operation time exceeding 60 min (odds ratio [OR] 8.55; 95% confidence interval [CI] 3.82–19.13), a maximum diameter exceeding 7 mm (OR 5.03; 95% CI, 2.24–11.29), and the presence of radiological evidence indicating pneumonia (OR 2.69; 95% CI, 1.27–5.69). Conclusion During flexible bronchoscopy procedures aimed at FB removal in pediatric patients, there is an increased susceptibility to hypoxemia. Factors including extended operation duration, larger FB dimensions, and radiographic evidence suggestive of pneumonia significantly contribute to a heightened risk of hypoxemia.

Abstract Background The SARS CoV-2 pandemic has resulted in more than 1.1 million deaths in the USA alone. Therapeutic options for critically ill patients with COVID-19 are limited. Prior studies showed that post-infection treatment of influenza A virus-infected mice with the liponucleotide CDP-choline, which is an essential precursor for de novo phosphatidylcholine synthesis, improved gas exchange and reduced pulmonary inflammation without altering viral replication. In unpublished studies, we found that treatment of SARS CoV-2-infected K18-hACE2-transgenic mice with CDP-choline prevented development of hypoxemia. We hypothesize that administration of citicoline (the pharmaceutical form of CDP-choline) will be safe in hospitalized SARS CoV-2-infected patients with hypoxemic acute respiratory failure (HARF) and that we will obtain preliminary evidence of clinical benefit to support a larger Phase 3 trial using one or more citicoline doses. Methods We will conduct a single-site, double-blinded, placebo-controlled, and randomized Phase 1/2 dose-ranging and safety study of Somazina® citicoline solution for injection in consented adults of any sex, gender, age, or ethnicity hospitalized for SARS CoV-2-associated HARF. The trial is named “SCARLET” (Supplemental Citicoline Administration to Reduce Lung injury Efficacy Trial). We hypothesize that SCARLET will show that i.v. citicoline is safe at one or more of three doses (0.5, 2.5, or 5 mg/kg, every 12 h for 5 days) in hospitalized SARS CoV-2-infected patients with HARF (20 per dose) and provide preliminary evidence that i.v. citicoline improves pulmonary outcomes in this population. The primary efficacy outcome will be the SpO2:FiO2 ratio on study day 3. Exploratory outcomes include Sequential Organ Failure Assessment (SOFA) scores, dead space ventilation index, and lung compliance. Citicoline effects on a panel of COVID-relevant lung and blood biomarkers will also be determined. Discussion Citicoline has many characteristics that would be advantageous to any candidate COVID-19 therapeutic, including safety, low-cost, favorable chemical characteristics, and potentially pathogen-agnostic efficacy. Successful demonstration that citicoline is beneficial in severely ill patients with SARS CoV-2-induced HARF could transform management of severely ill COVID patients. Trial registration The trial was registered at www.clinicaltrials.gov on 5/31/2023 (NCT05881135). Trial status Currently enrolling.

Abstract Acute type A aortic dissection is a life-threatening cardiovascular disease characterized by rapid onset and high mortality. Emergency surgery is the preferred and reliable treatment option. However, postoperative complications significantly impact patient prognosis. Hypoxemia, a common complication, poses challenges in clinical treatment, negatively affecting patient outcomes and increasing the risk of mortality. Therefore, it is crucial to study and comprehend the risk factors and treatment strategies for hypoxemia following acute type A aortic dissection to facilitate early intervention.

We report the feasibility of a combined approach of very low low tidal volume (VT) and mild therapeutic hypothermia (MTH) to decrease the ventilatory load in a severe COVID-19-related acute respiratory distress syndrome (ARDS) cohort. Inclusion criteria was patients ≥18-years-old, severe COVID-19-related ARDS, driving pressure ∆P >15 cmH2O despite low-VT strategy, and extracorporeal therapies not available. MTH was induced with a surface cooling device aiming at 34°C. MTH was maintained for 72 h, followed by rewarming of 1°C per day. Data were shown in median (interquartile range, 25%–75%). Mixed effects analysis and Dunnett’s test were used for comparisons. Seven patients were reported. Ventilatory load decreased during the first 24 h, minute ventilation (VE) decreased from 173 (170–192) to 152 (137–170) mL/kg/min (P = 0.007), and mechanical power (MP) decreased from 37 (31–40) to 29 (26–34) J/min (P = 0.03). At the end of the MTH period, the VT, P, and plateau pressure remained consistently close to 3.9 mL/kg predicted body weight, 12 and 26 cmH2O, respectively. A combined strategy of MTH and ultraprotective mechanical ventilation (MV) decreased VE and MP in severe COVID-19-related ARDS. The decreasing of ventilatory load may allow maintaining MV within safety thresholds.

Abstract Introduction Administration of oxygen therapy is common, yet there is a lack of knowledge on its ability to prevent cellular hypoxia as well as on its potential toxicity. Consequently, the optimal oxygenation targets in clinical practice remain unresolved. The novel PpIX technique measures the mitochondrial oxygen tension in the skin (mitoPO2) which allows for non-invasive investigation on the effect of hypoxemia and hyperoxemia on cellular oxygen availability. Results During hypoxemia, SpO2 was 80 (77–83)% and PaO2 45(38–50) mmHg for 15 min. MitoPO2 decreased from 42(35–51) at baseline to 6(4.3–9)mmHg (p 200 mmHg were both associated with a reduction in mitoPO2. Conclusions Hypoxemia decreases mitoPO2 profoundly, despite complete compensation of global oxygen delivery. In addition, hyperoxemia also decreases mitoPO2, accompanied by a reduction in microcirculatory perfusion. These results suggest that mitoPO2 can be used to titrate oxygen support.

Abstract Background Anesthesia for spinal muscular atrophy (SMA) patients undergoing spinal deformity surgery is challenging. We report an unusual case of an SMA girl who developed severe intraoperative hypoxemia and hypotension during posterior spinal fusion related with surgical positioning. Case presentation A 13-yr-old girl diagnosed with SMA type 2, severe kyphoscoliosis and thoracic deformity was scheduled for elective posterior spinal fusion. She developed severe hypoxemia and profound hypotension intraoperatively in the prone position with surgical table tilted 45° to the right. Though transesophageal echocardiography (TEE) could not be performed due to limited mouth opening, her preoperative computed tomography revealed a severely distorted thoracic cavity with much reduced volume of the right side. A reasonable explanation was when the surgeons performed surgical procedure with the tilted surgical table, the pressure was directly put on the shortest diameter of the significantly deformed thoracic cavity, causing severe compression of the pulmonary artery, resulting in both hypoxemia and hypotension. The patient stabilized when the surgical table was tilted back and successfully went through the surgery in the leveled prone position. Conclusions Spinal fusion surgery is beneficial for SMA patients in preventing scoliosis progression and improving ventilation. However, severe scoliosis and thoracic deformities put them at risk of both hemodynamic and respiratory instability during surgical positioning. When advanced monitoring like TEE is not practical intraoperatively, preoperative imaging may help with differential diagnosis, and guide the surgical positioning to minimize mechanical compression of the thoracic cavity, thereby helping the patient complete the surgery safely.

Abstract Objectives Hypoxia is a known feature of sickle cell anaemia (SCA) which results from chronic anaemia and recurrent vaso-occlusive crisis (VOC) which can cause tissue ischaemia that leads to an end organ damage. The hallmark of SCA is chronic anaemia and recurrent vaso-occlusive crisis. The aim of this study is to compare the oxygen saturation of sickle cell anaemic individuals with the normal haemoglobin type (Hb AA) control and also to determine the prevalence of hypoxemia among SCA. Results Two-hundred and twenty-two (136 Hb SS and 86 Hb AA) participated in the study. The mean ± SD of age (years), oxygen saturation (%) and pulse rate (bpm) of participants with sickle cell anaemia and Hb AA control were 21.85 ± 3.04 and 22.14 ± 3.18 (t = 0.701, p = 0.436), 95.21 ± 3.02 and 98.07 ± 0.81 (t=-8.598, p

Introduction: Paediatric Acute Respiratory Distress Syndrome (PARDS) remains a major cause of mortality and morbidity in Paediatric Intensive Care Units (PICU) despite various advanced management strategies. The management and outcome of PARDS depend on the severity of the disease. Aim: To study the clinical profile in terms of aetiology and outcome of paediatric patients with moderate to severe Acute Respiratory Distress Syndrome (ARDS) in the PICU. Materials and Methods: A prospective cohort study was conducted at the PICU in Dr. BC Roy Postgraduate Institute of Paediatric Sciences, Kolkata, West Bengal, India, from July 2018 to June 2019. A total of 120 children aged between two months and 12 years who developed moderate to severe ARDS according to Paediatric Acute Lung Injury Consensus Conference (PALICC) criteria were included. Demographic details, different risk factors, morbidity patterns, and outcomes were recorded. Patients were categorised into three groups based on Positive End Expiratory Pressure (PEEP): 5-8 cm of H2O, 9-12 cm of H2O, and >12 cm of H2O. Based on Peak Inspiratory Pressure (PIP), patients were divided into two groups: 12 cm of H2O group and 84.4% in the PIP 30-35 cm of H2O group. Conclusion: The majority of ARDS cases are due to direct lung injury caused by pneumonia, and the outcome is better than in cases of indirect lung injury. Mortality is nearly twice as high in severe ARDS as in moderate ARDS.

Background: Many hospitalized patients decline in functional status after discharge, but functional decline in emergency admissions with hypoxemia is unknown. The primary aim of this study was to study functional outcomes as a clinical endpoint in a cohort of patients with acute hypoxemia. Methods: A multicenter prospective observational study was conducted in patients with new-onset hypoxemia emergently admitted to two respiratory departments at a university hospital and an academic teaching hospital. Using the WHO scale, the patients’ functional status 4 weeks before admission and at hospital discharge was assessed. The type and duration of oxygen therapy, hospital length of stay and survival and risk of hypercapnic failure were recorded. Results: A total of 151 patients with a median age of 74 were included. Two-thirds declined in functional status by at least one grade at discharge. A good functional status (OR 4.849 (95% CI 2.209–10.647)) and progressive cancer (OR 6.079 (1.197–30.881)) were more associated with functional decline. Most patients were treated with conventional oxygen therapy (n = 95, 62%). The rates of in-hospital mortality and need for intubation were both 8%. Conclusions: Patients with acute hypoxemia in the emergency room have a poorer functional status after hospital discharge. This decline may be of multifactorial origin.

Introduction: Acute respiratory failure is the most common clinical feature in patients with severe Coronavirus Disease -2019 (COVID-19) who are admitted to an Intensive Care Unit (ICU) and may require invasive mechanical ventilation, which is generally linked with a high fatality rate. Patients with established co-morbidities, such as diabetes, invariably fall into the category of patients with severe disease presentation and rapid disease progression. Aim: To study the clinical outcomes of COVID-19 diabetic patients after sequential oxygen therapy using a reservoir bag mask, High Frequency Nasal Oxygen (HFNO), and Non-invasive Ventilation (NIV). Materials and Methods: In this retrospective cohort study, adhering to the STROBE statement criteria, the authors included 150 patients suffering from COVID-19 acute respiratory failure, who were known diabetics, divided into three groups based on admission oxygen saturation and Respiratory Rate (RR) for Non-Rebreather Bag-Mask (NRBM) therapy, HFNO, and NIV. For two weeks, all patients were monitored, and measures such as Saturation of peripheral Oxygen (SpO2), Respiratory Rate (RR) escalation of oxygen requirement, glycaemic management, compliance and problems with continued oxygen therapy, the need for invasive mechanical ventilation, and mortality were recorded. The recorded parameters among the three groups were compared using Analysis of Variance (ANOVA) test. Results: Among the demographic parameters recorded, the authors noted that individuals older than 50-55 years of either sex were admitted for HFNO (56.02±11.71 years) and NIV (54.28±14.67 years) therapy, whereas no such preponderance was noted among the two genders. Significant results were noted in all three groups in terms of the escalation of oxygen fraction (FiO2) requirements on the 10th day of observation (NRBM 12.63±2.48%, HFNO 37.74±13.56%, NIV 82.44±11.11%). The need for tracheal intubation was higher in patients in the NIV group (10) compared to the HFNO (9) and NRBM (1) groups. Patients whose blood sugar levels remained uncontrolled throughout the course of observation in the study were disparagingly seen to have been a part of the HFNO and NIV groups, and hence the subsequent mortality. Conclusion: There was a steady escalation of mean oxygen requirements in all three groups of oxygen therapy over the course of two weeks, coinciding with the ensuing ‘cytokine storm’ associated with Severe Acute Respiratory Syndrome- Coronavirus- 2 (SARS-CoV-2) infection. This trend of escalation of oxygen requirement also in turn coincided with the raised glycaemic charting trends of the patients over the same course of two weeks, delineating those individuals with diabetes mellitus, in view of their compromised immunity and innate pro -inflammatory state, are more prone to develop severe form of the disease with more serious complications, which may even lead to mortality. With regards to the compliance, NRBM & HFNO provided best results in comparison to NIV. The rates of complications were also noted to be higher with the use of NIV in this instance.

Background Inherited hemoglobin disorders are common in clinical practice. While qualitative (i.e. sickle cell disease) and quantitative (thalassemia) hemoglobinopathies are usually diagnosed clinically and confirmed through simple laboratory assessments, hemoglobin variants with altered oxygen affinity often go undetected due to their typically silent clinical presentation. Hemoglobin (Hb) J-Auckland, a low oxygen affinity hemoglobin variant first described in 1987 in Auckland, New Zealand, is one such silent disorder.Case presentation We report for the first time a clinically evident case of previously undiagnosed Hb J-Auckland in an 8-year-old girl who presented with unexplained hypoxemia at high altitude. Her oxygen level was corrected with supplemental oxygen and when assessed at low altitude. A brief discussion of the diagnostic approach and clinical implications is provided.Conclusion Standard hemoglobin analysis is essential for the evaluation of suspected altered affinity hemoglobinopathy, and genetic testing is often required for definitive diagnosis. Early recognition and diagnosis of these variants can prevent mismanagement and improve patient outcomes.

High altitude polycythemia is a maladaptation of highlanders exposed to hypoxic environment, leading to high blood viscosity and severe cardiorespiratory dysfunction. Prolonged hypoxia causes respiratory depression and severe hypoxemia, and further mediates changes in genetic and molecular mechanisms that regulate erythropoiesis and apoptosis, ultimately resulting in excessive erythrocytosis (EE). This updated review investigated the maladaptive mechanisms of EE, including respiratory chemoreceptor passivation, sleep-related breathing disorders, sex hormones, iron metabolism, and hypoxia-related factors and pathways.

BackgroundDexmedetomidine (DEX) is a highly selective alpha 2 receptor agonist that has the advantage of causing less respiratory depression than other sedative agents. We evaluated the add-on effects of DEX on sedation among pediatric patients who received midazolam and pentazocine during cardiac catheterization.Methods120 cardiac catheterization procedures in 110 patients under deep sedation at Department of Pediatrics, Kanazawa University Hospital from January 2013 to August 2018: 63 procedures without DEX (i.e., non-DEX group) and 57 procedures with DEX (i.e., DEX group). Intravenous midazolam and pentazocine were used in both groups, and DEX without an initial loading dose (0.6 μg/kg/h) was used in the DEX group. We retrospectively investigated complications during catheterization, doses of sedative agents, and changes in vital signs.ResultsHypoxemia requiring oxygen administration during catheterization tended to be higher in the non-DEX group than in the DEX group (4.8% vs. 0%). Additional dose of midazolam was significantly lower in the DEX group (median [IQR]: 0.05 mg/kg [0–0.11]) than in the non-DEX group [0.09 mg/kg (0–0.23), p = 0.0288]. The additional dose of midazolam in the non-DEX group with hypoxemia was significantly higher than the dose used in the non-DEX group without hypoxemia. No case of bradycardia below the criteria for bradycardia occurred and no serious complications occurred in the DEX group.ConclusionThe use of intravenous DEX in combination with midazolam and pentazocine in pediatric cardiac catheterization may reduce the need for an additional dose of midazolam and may contribute to the prevention of airway complications associated with respiratory depression caused by sedative agents.

Background: This study compared the efficacy of oropharyngeal airways (OA) and nasopharyngeal airways (NA) in maintaining oxygenation during painless fiberoptic bronchoscopy (PFB) in patients sedated with remimazolam besylate. Methods: Two hundred and fifty-two patients were randomized to the OA or NA group. Remimazolam besylate was used for anesthesia induction and maintenance in both groups. We measured and recorded several physiological parameters, including mean arterial pressure, heart rate and oxygen saturation (SpO2), at various time points: before anesthesia (T1), after anesthesia induction (T2), immediately after the bronchoscope reached the trachea (T3), during the procedure (T4), and 5 min after transfer to the post-anesthesia care unit (T5). The incidence and frequency of hypoxemia, minimum SpO2 during the procedure and patient awakening time after flumazenil administration were also recorded. Additionally, the relationship between minimum SpO2 and body mass index (BMI) was investigated. Results: Patients in the NA group experienced a higher incidence of hypoxemia compared to the OA group. Patients in the OA group maintained higher SpO2 levels at T3 and had a higher minimum SpO2 during the procedure than the NA group. Furthermore, a significant negative correlation was observed between minimum SpO2 and BMI. Following flumazenil anesthesia reversal, nearly 97 % of patients awakened within 1 min. Conclusions: This study suggests that OA may provide a better safety profile than NA by preserving respiratory function during PFB.

BackgroundThe objective of this study was to conduct a systematic review and meta-analysis of the clinical application effects of transnasal high flow nasal cannula compared to other conventional modalities for oxygen therapy devices in patients undergoing bronchoscopy.MethodsA comprehensive literature search was conducted in multiple English databases, including PubMed, Web of Science, and Cochrane Library, to collect relevant studies on the application of high flow nasal cannula in patients undergoing bronchoscopy, and conducted a meta-analysis utilizing RevMan 5.4 software, following the predetermined inclusion and exclusion criteria.ResultsA total of 12 studies meeting the inclusion criteria were included, involving 1,631 patients (HFNC group: n = 811, other oxygen therapy group: n = 820). The meta-analysis results demonstrated that HFNC significantly reduced the incidence of hypoxemia and improved the minimum oxygen saturation compared to conventional oxygen therapy (RR = 0.27, 95% CI: 0.18–0.41, p

PurposeThis study aimed to systematically evaluate the clinical effects of using transnasal high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) in patients undergoing gastrointestinal endoscopy.MethodsA comprehensive literature search was conducted from 2004 to April 2024 to collect relevant studies on the application of HFNC in patients undergoing gastrointestinal endoscopy. Multiple Chinese and English databases, including China National Knowledge Infrastructure (CNKI), Wanfang Data, Web of Science, PubMed, and Cochrane Library, were searched systematically for randomized controlled trials (RCTs). Two researchers independently screened the literature, extracted data, and assessed the risk of bias in the included studies. RevMan 5.4 software was utilized for conducting the network meta-analysis.ResultsA total of 12 RCTs involving 3,726 patients were included. Meta-analysis results showed that HFNC reduced the incidence of hypoxemia and improved the minimum oxygen saturation (SpO2) compared with COT [odds ratio (OR) = 0.39, 95% confidence interval (CI): 0.29–0.53], [mean difference (MD) = 4.07, 95% CI: 3.14–5.01], and the difference was statistically significant. However, the baseline SpO2 levels and incidence of hypercapnia were not statistically significantly different between the HFNC and COT groups [MD = −0.21, 95% CI: −0.49–0.07]; [OR = 1.43, 95% CI: 0.95–2.15]. In terms of procedure time, the difference between HFNC and COT was not statistically significant, and subgroup analyses were performed for the different types of studies, with standard deviation in the gastroscopy group (MD = 0.09, 95% CI: −0.07–0.24) and the endoscopic retrograde cholangiopancreatography group (MD = 0.36, 95% CI: −0.50–1.23). The results demonstrated a significant reduction in the adoption of airway interventions in the HFNC group compared to the COT group (OR = 0.16, 95% CI: 0.05–0.53), with a statistically significant difference; this result was consistent with those of the included studies.ConclusionThe application of HFNC improves the incidence of hypoxemia, enhances oxygenation, and reduces airway interventions during gastrointestinal endoscopy. However, HFNC does not significantly affect baseline SpO2, hypercapnia, or procedure time. The limitations of this study must be acknowledged, and further high-quality studies should be conducted to validate these findings.

The main method for estimating the level of arterial blood oxygenation is pulse oximetry, which has the advantages of being fast, simple, reliable, and non-invasive. However, in well-known pulse oximeters, oxygen saturation is determined only by hemoglobin functional fractions, which reduces the device accuracy and is unacceptable in certain clinical cases. The known pulse oximeter improvement that considers the dysfunctional fraction concentration, especially carboxyhemoglobin, when measuring the level of blood oxygenation is an actual scientific and technical task. The research subjects. Mathematical, algorithmic, and technical support of a pulse oximeter that measures blood oxygenation levels considering the carboxyhemoglobin concentration. Objective. To expand the pulse oximeter functionality to consider the concentration of carboxyhemoglobin in arterial blood. Methods. Methods of computer simulation for developing a model and estimating the pulse oximeter accuracy that measures the blood oxygenation level considering the carboxyhemoglobin concentration. Results. The theoretical statements of measuring the level of blood oxygenation considering the carboxyhemoglobin concentration and the simplest pulse oximeter structural diagram for measuring are developed. An additional LED used in the pulse oximeter is proposed, and the wavelength choice is justified on the condition of maximizing the carboxyhemoglobin contribution to the optical density of the biological object. Computer models of a traditional pulse oximeter and a pulse oximeter with an additional LED were developed, simulation research was conducted using the developed models, and the device accuracy for measuring the level of blood oxygenation was estimated considering the carboxyhemoglobin concentration. Conclusions. Simulation studies based on the developed models show that the proposed pulse oximeter, compared with the known one, allows determining and estimating a decrease in blood oxygenation caused by the carboxyhemoglobin concentration increasing in the patient’s blood. Considering that light is also absorbed by the third derivative of hemoglobin, carboxyhemoglobin, increases the accuracy of the proposed pulse oximeter in measuring functional saturation.

Abstract Introduction Portable oxygen concentrators (POCs) are medical devices that provide supplemental oxygen to patients requiring long-term oxygen therapy. However, little information is available on day-to-day patterns of how or even whether patients actively switch between their POC mobility features and flow setting options. Methods A retrospective analysis was conducted to assess POC usage among patients who used an Inogen One G5 POC in the USA. This study aimed (1) to describe the patterns of use of POCs, (2) to analyze their compatibility with the prescribed oxygen therapy settings, and (3) to demonstrate the contribution of POC usage to get a standardized long-term oxygen therapy (LTOT). Data were directly downloaded from the devices returned for service or at the end of the Medicare Durable Medical Equipment rental period and streamed via a mobile application from 2018 to 2022. Daily usage, disconnections from the device, use of prescribed pulse delivery settings, breaths per minute, power sources, and movement with the POC were assessed. Device alert histories were also examined. Results Data revealed a mean daily usage of 4.29 ± 3.23 h/day, ranging from 0.35 to 15.52 h/day. The prescribed pulse delivery setting was used by 31.34% of patients for at least 80% of their POC use time. When the POC was on battery power, patients were moving/mobile 41.99 ± 33.33% of the time. On the basis of the device-generated alerts, some patients continued to use their POC very close to or even beyond the lifetime of the column/sieve bed. Alerts or alarms potentially requiring repair occurred at a rate of 1.63 events per 100 years of use, indicating that device reliability did not significantly influence the use patterns. Conclusion Patients used their POCs when mobile and at rest. A large proportion of patients adjust their POC settings during the day, which potentially indicates the need for the dynamic individualization of oxygen dose delivery to match activities of daily living or sleep. Patients require follow-up to ensure timely replacement of POC columns.

Abstract Background Pulmonary arteriovenous fistula (PAVF) is a rare disease, which can lead to the direct return of unoxidized venous blood to pulmonary veins and left heart, resulting in right-to-left shunt leading to hypoxia. Long term, the right-to-left shunt will cause severe pathophysiological changes in the patient’s body and pulmonary circulation, and the prognosis will be poor if PAVF is not treated timely. Case presentation Here, we report the case of a 71-year-old man who presented with chest tightness and shortness of breath. After a series of examinations, PAVF and giant hemangioma were diagnosed, which are difficult to operate.Transcatheter interventional therapy was initiated. The patient recovered on the third day after operation and was discharged smoothly. During the long-term follow-up of nearly 4 years after discharge, the general condition and quality of life of the patient basically returned to normal. Conclusions PAVF is rare but very important clinical problem. When the clinical manifestations of persistent unexplained hypoxia appear, it is necessary to fully consider the possibility of PAVF. Once the diagnosis of PAVF is clear, timely treatment is recommended to avoid deterioration of the disease and affecting the prognosis.

Abstract Objectives The objective of this study is to assess frequency and risk factors for intraoperative hypoxemia of the lower limbs during robot‐assisted radical prostatectomy (RARP). Trendelenburg position during RARP may contribute to hypoxemia and compartment syndrome (CS) of the lower limbs as a major but rare complication. Patients and methods This prospective study included patients undergoing RARP for prostate cancer. Preoperative calculation of the ankle‐brachial‐index (ABI) was performed. Peripheral oxygen saturation (SpO2) at the toes was routinely measured. Occurrence of SpO2 levels of

Litopenaeus vannamei, also known as the Pacific white shrimp or white foot shrimp, is a member of the Crustacea, Decapoda, Palaemonidae, and Litopenaeus families. This species is mainly distributed on the Mexican and Pacific coasts of South America. Owing to its excellent immune characteristics, L. vannamei is currently one of the most important economic shrimp species in China.In the aquaculture process and under natural environmental conditions, low dissolved oxygen (DO) condition or even hypoxia frequently occurs. Under high-density culture operations, acute hypoxia is one of the major factors affecting the survival rate of shrimp and the quality of aquaculture water, causing not only a large number of shrimp deaths in the short term but also water decay and fermentation, increased turbidity, and other phenomena. The genetic improvement of L. vannamei, as well as the screening and breeding of exceptionally tolerant species under low DO conditions, are crucial to the sustainable development of the shrimp industry. Global selective breeding efforts based on quantitative genetics to improve genetic progress in L. vannamei have been extensive, and the main targeted traits were growth, survival, disease resistance, and stress tolerance. Few studies have been conducted on the evaluation of genetic parameters and screening of strains for hypoxic tolerance traits in L. vannamei; in particular, the genetic parameters and cytological characteristics of key tissues of L. vannamei under short-term highly lethal DO levels (0.3–0.5 mg/L) have not been reported.In this study, we used two strains of L. vannamei, GK (a strain with high disease resistance) and K (a strain with fast growth characteristics), each with a total of 6 560 shrimp from 41 families, to count survival traits at highly lethal DO levels, analyze differences in hypoxia tolerance traits between strains and within families of the same strain, and evaluate genetic parameters. Individual gill, muscle, and hepatopancreas tissues from families with significantly different tolerance levels were histologically investigated and compared at the cellular level. The results showed that there was a significant difference (P < 0.05) in semi-lethal survival (SS50) between families within both the GK and K strains when overall semi-lethality was reached under hypoxic environmental conditions of 0.3 mg/L, with SS50 values of 49.30% for GK and 42.52% for K. The coefficients of variation for survival times of families within each strain were 60% and 45% for GK and K, respectively. Using the threshold trait animal model, the genetic parameters were estimated to be between 0.345±0.031 and 0.378±0.029 using the survival status of the individual at semi-lethal levels as the observed value (1 for survival and 0 for death), and the heritability was between 0.219±0.031 and 0.237±0.029 following transformation on a continuously varying scale of observed values, indicating a moderate level of heritability. Moreover, the gill, muscle, and hepatopancreas tissues of the hypoxia-tolerant and hypoxia-sensitive families in the GK strain exhibited varying degrees of damage and different degrees of variations in the physiological characteristics of resistance among different families. This may be related to the resistance tolerance strength of different GK families. In contrast to the gill, muscle, and hepatopancreas tissues of the control shrimp, the equivalent tissues of shrimp from tolerant and sensitive families showed different degrees of changes following stress. The gill lumen of the filaments of the experimental group from sensitive families increased, the number of blood cells increased, the structure of the epithelial layer was gradually destroyed or even disintegrated, the vacuolation of the hepatopancreas was severe, the lumen of the ducts became irregularly deformed, and the muscle tissue muscle bundle interval widened with a certain degree of deformation. These results suggested that there was abundant genetic variation in the tolerance traits of L. vannamei at highly lethal DO levels and that this species was amendable to selective breeding practices. This study provides a reference and basis for the selection and breeding of hypoxia-tolerant traits in L. vannamei.

BACKGROUND: Acute cerebral infarction (ACI) is one of the most common ischemic cerebrovascular diseases in neurology, with high morbidity, mortality, and disability. Early thrombolytic treatment of ACI has significant efficacy, but intraprocedural complications of hypoxemia can significantly reduce the efficacy. This study aims to analyze the risk factors for intraprocedural hypoxemia in patients with ACI, so as to take effective measures in advance to reduce the likelihood of adverse patient outcomes. METHODS: We retrospectively analyzed a total of 238 patients with ACI treated with vascular interventions from May 2017 to May 2022. To assess and collate the patients' characteristics, factors associated with the development of intraprocedural hypoxemia. The independent risk factors for the development of intraprocedural hypoxemia were analyzed by binary logistic regression. RESULTS: A total of 238 patients were included in this study. Of these, intraprocedural hypoxemia occurred in 89 (37.4%). The results showed that old age (odds ratio [OR] = 2.666, P = 0.009), obesity (OR = 3.029, P = 0.003), smoking history (OR = 2.655, P = 0.010), preoperative oxygen saturation (SpO2) (OR = 0.001, P = 0.042), preoperative C-reactive protein (OR = 1.216, P = 0.002), and time from puncture to vascular recanalization (OR = 1.135, P = 0.000) were independent risk factors for intraprocedural hypoxemia in patients. The prognosis of the patients was assessed according to the modified Rankin scale, and the prognosis of the nonhypoxemia group was significantly better than that of the hypoxemia group. Regression analysis showed that intraprocedural hypoxemia (OR = 0.360, P = 0.001), postoperative lower extremity vein thrombosis (OR = 0.187, P = 0.018), hydrocephalus (OR = 0.069, P = 0.015), intracranial hemorrhage (OR = 0.116, P = 0.002), and reocclusion (OR = 0.217, P = 0.036) were independent risk factors for poor prognosis. CONCLUSIONS: Currently, intravascular hypoxemia in patients with ACI has a serious impact on prognosis. Clinical work should attach great importance to the clinical characteristics of patients, identify relevant risk factors, and aggressively take personalized therapeutic actions to improve patients' prognosis.

OBJECTIVES: High-flow nasal cannula (HFNC) oxygen therapy has been used as an initial ventilatory support for coronavirus disease 2019 (COVID-19) patients with mixed levels of acute hypoxemic respiratory failure (AHRF). However, the effectiveness of HFNC when used as initial ventilatory support in COVID-19 patients with severe AHRF exclusively is not well documented. Ratio of oxygen saturation (ROX) index (ROX = [SpO2/fraction of inspired oxygen]/respiratory rate) was shown to predict the outcome of HFNC in intensive care unit patients. Our study aimed to evaluate the utility of the ROX index for predicting HFNC therapy success/failure in COVID-19 patients with severe AHRF when HFNC is used as the first line of ventilatory support. METHODS: Retrospective study in 67 COVID-19 patients with severe AHRF receiving HFNC in the emergency department at a tertiary care academic medical center. ROX index was determined at 0, 2, 6, 12, and 24 h of HFNC onset. The need to escalate to noninvasive or invasive ventilatory support was documented. The receiver operating characteristic curves were performed and areas under the curves (AUCs) were calculated to evaluate the accuracy of ROX index for differentiating between patients who will succeed or fail HFNC therapy. RESULTS: HFNC therapy was successful in 19 patients (28.1%) and failed in 48 patients (71.6%). ROX index after 6 h of HFNC initiation had the best predictive capacity for the outcome of HFNC therapy (AUC = 0.78). ROX index >4.4 at 6 h of HFNC onset was significantly associated with HFNC success/failure. CONCLUSION: ROX index at 6 h after initiating HFNC therapy in COVID-19 patients with severe AHRF has a good predictive capacity for HFNC success/failure.

Abstract Background Legionella remains underdiagnosed in the intensive care unit and can progress to acute respiratory distress syndrome (ARDS), multiorgan failure and death. In severe cases, venovenous extracorporeal membrane oxygenation (VV-ECMO) allows time for resolution of disease with Legionella-targeted therapy. VV-ECMO outcomes for Legionella are favorable with reported survival greater than 70%. Rapid molecular polymerase chain reaction (PCR) testing of the lower respiratory tract aids in diagnosing Legionella with high sensitivity and specificity. We present a unique case of a patient with a positive COVID-19 test and ARDS who suffered a cardiac arrest. The patient was subsequently cannulated for VV-ECMO, and after lower respiratory tract PCR testing, Legionella was determined to be the cause. She was successfully treated and decannulated from VV-ECMO after eight days. Case presentation A 53-year-old female presented with one week of dyspnea and a positive COVID-19 test. She was hypoxemic, hypotensive and had bilateral infiltrates on imaging. She received supplemental oxygen, intravenous fluids, vasopressors, broad spectrum antibiotics, and was transferred to a tertiary care center. She developed progressive hypoxemia and suffered a cardiac arrest, requiring ten minutes of CPR and endotracheal intubation to achieve return of spontaneous circulation. Despite mechanical ventilation and paralysis, she developed refractory hypoxemia and was cannulated for VV-ECMO. Dexamethasone and remdesivir were given for presumed COVID-19. Bronchoscopy with bronchoalveolar lavage (BAL) performed with PCR testing was positive for Legionella pneumophila and negative for COVID-19. Steroids and remdesivir were discontinued and she was treated with azithromycin. Her lung compliance improved, and she was decannulated after eight days on VV-ECMO. She was discharged home on hospital day 16 breathing room air and neurologically intact. Conclusions This case illustrates the utility of rapid PCR testing to diagnose Legionella in patients with respiratory failure and the early use of VV-ECMO in patients with refractory hypoxemia secondary to Legionella infection. Moreover, many patients encountered in the ICU may have prior COVID-19 immunity, and though a positive COVID-19 test may be present, further investigation with lower respiratory tract PCR testing may provide alternative diagnoses. Patients with ARDS should undergo Legionella-specific testing, and if Legionella is determined to be the causative organism, early VV-ECMO should be considered in patients with refractory hypoxemia given reported high survival rates.

Objective·To investigate the anesthetic effect of PetCO2 monitoring nasopharyngeal airway on preventing hypoxia in patients with obstructive sleep apnea syndrome (OSAS) during magnifying endoscopy.Methods·Eighty OSAS patients who underwent magnifying endoscopy anesthesia in Xuchang Central Hospital of Henan Province from February to June 2023 were randomly divided into PetCO2 monitoring nasopharyngeal airway group (group T) and traditional nasopharyngeal airway group (group B), with 40 cases in each group. General information, perioperative data and total anesthetic dosage of the two groups of patients were collected and compared. The systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and pulse oxygen saturation (SpO2) of the two groups of patients before anesthesia (T0), at the time of entering the endoscopy (T1), 3 min after entering the endoscopy (T2), 10 min after entering the endoscopy (T3) and at the end of endoscopy (T4) were observed and recorded, respectively. The incidence of body movement and hypoxemia, and the effects of preventing hypoxia (including mask ventilation, jaw-lift support and chest compressions to assist breath) of the two groups of patients were recorded.Results·There were no significant differences in general information, perioperative data and total anesthetic dosage between the two groups. At T1 and T2, SpO2 in group T was higher than that in group B (T1: P=0.041,T2: P=0.012), and there was no statistically significant difference in SBP, DBP and HR between the groups; at other time points, there was no statistically significant difference in the four indicators between the two groups. Compared with group B, the incidences of body movement, hypoxemia, mask ventilation, jaw-lift support and chest compressions to assist breath in group T were all decreased (all P=0.000).Conclusion·PetCO2 monitoring nasopharyngeal airway can reduce the incidence of hypoxia during magnifying endoscopy in patients with OSAS, with minimal adverse events. Also, it can detect the status of lung ventilation in time, guide clinical intervention, reduce complications and improve the safety of magnifying endoscopy anesthesia.

AbstractBackground Hypoxemia often occurs in outpatients undergoing anesthesia-assisted esophagogastroduodenoscopy (EGD). However, there is a scarcity in tools to predict the hypoxemia risk. We aimed to solve this problem by developing and validating machine learning (ML) models based on preoperative and intraoperative features.Methods All data were retrospectively collected from June 2021 to February 2022. The most appropriate predictive features were selected by the least absolute shrinkage and selection operator, which were incorporated and modelled by 4 ML algorithms. The area under the precision-recall curve (AUPRC) was used as the main evaluation metric to select the best models, and the selected models were compared with the STOP-BANG score. Their predictive performance was visually interpreted by SHapley Additive exPlanations. The primary endpoint of this study was hypoxemia during the procedure, defined as at least one reading of pulse oximetry < 90% without probes misplacement from the anesthesia induction beginning to the end of EGD, while the secondary endpoint was hypoxemia during induction, from the induction beginning to the start of endoscopic intubation.Results Of 1160 patients in the derivation cohort, 112 patients (9.6%) developed intraoperative hypoxemia, of which 102 (8.8%) occurred during the induction period. In temporal and external validation, no matter whether based on preoperative variables or still based on preoperative plus intraoperative variables, our models showed excellent predictive performance for the two endpoints, significantly better than STOP-BANG score. In the model interpretation section, preoperative variables (airway assessment indicators, pulse oximeter oxygen saturation and BMI) and intraoperative variables (the induced propofol dose) made the highest contribution to the predictions.Conclusions To our knowledge, our ML models were the first to predict hypoxemia risk, which achieved excellent overall predictive ability integrating various clinical indicators. These models have the potential to become an effective tool for adjusting sedation strategies flexibly and reducing the workload of anesthesiologists.KEY MESSAGESThis study is the first model employing ML methods based on preoperative and preoperative plus intraoperative variables for predicting the risk of hypoxemia during induction and the whole EGD procedure respectively.Our four models achieved satisfactory predictive performance and outperformed STOP-BANG score in terms of AUPRC in the temporal and external validation cohorts respectively.We found that the relevant variables of airway assessment should be fully taken into account when analyzing the risk factor of hypoxemia, and the effect of patients’ age on their hypoxemia risk should be considered in conjunction with the propofol dose.

ObjectivesTo evaluate the safety and feasibility of high flow oxygen therapy (HFOT), and to record SpO2 and desaturation episodes in dogs and cats receiving HFOT or conventional oxygen therapy (COT) during bronchoscopy ± bronchoalveolar lavage (BAL).Materials and methodsDogs and cats undergoing bronchoscopy ± BAL between January and May 2023 were included in the study. Patients were randomly allocated to two groups: HFOT (HFOT group; two cats and four dogs) and COT (COT group; one cat and five dogs). HFOT and COT were started at the beginning of the bronchoscopy. HFOT was delivered with a gas flow rate of 1 L/kg/min at an FiO2 of 100% and a temperature of 34°C (pediatric mode) or 37°C (adult mode). COT was delivered through the working channel of the bronchoscope at a rate of 1.5 L/min. The safety and feasibility of HFOT were assessed, and peripheral oxygen saturation (SpO2) was measured by pulse oximetry every 30 s throughout the procedure.Measurements and main resultsHFOT was feasible and safe in both dogs and cats with no complications reported. While there was no significant difference in the number of desaturation episodes (SpO2

Interstitial pneumonia is the most common and serious secondary lesion of dermatomyositis. In some cases, patients may develop severe acute pneumonia that can quickly progress to respiratory failure, resulting in high mortality rates. A 57-year-old woman with dermatomyositis and interstitial pulmonary fibrosis experienced severe hypoxemia due to pulmonary infection. Despite receiving various treatments after entering the intensive care unit (ICU), such as anti-infection therapy, lung recruitment, prone position ventilation, sedative and muscle relaxation, the patient’s oxygen saturation continued to decline. Electrical impedance tomography (EIT) monitoring revealed that prone position could not improve ventilation homogeneity. However, the patient’s ventilation/perfusion (V/Q) matching significantly improved 10 min after initiation of supine position ventilation combined with inhalation of nitric oxide (iNO). The patient’s PaO2/FiO2 (P/F) ratio increased from 86 mmHg to 150 mmHg at 30 min post-treatment. iNO treatment continued for 2 days. Then the patient’s condition improved and she was successfully weaned off the ventilator with rigorous monitoring and symptomatic care. The implementation of mechanical ventilation combined with iNO therapy rapidly improved V/Q matching and oxygenation in a patient with hypoxemia caused by dermatomyositis complicated with interstitial pneumonia. This approach successfully avoided the need for invasive extracorporeal membrane oxygenation (ECMO) support.

Background: Organophosphorus insecticides are considered one of the commonest causes of morbidity and mortality due to poisoning worldwide. Severe organophosphorus poisoning can lead to multiple sometimes lethal metabolic and haematological abnormalities. METHODS: A total of 141 OP poisoning patients were admitted during the study period and their blood samples were collected on admission and analysed for the biochemical abnormalities. RESULTS: Out of 141 patients 76 were males (53.9%) and 65 were females (46.1%). Bradycardia with Pulse rate of less than 60 was seen in in 21 patients (14.7). Hypoxemia with oxygen saturation of less than 94% was seen in 32 (22.7%). leucocytosis with TLC o 11000 or more was seen in 19 patients (13.5%).101 patients (83.5%) had low serum choline esterase levels less than 1.5kU/L. Hypokalaemia with K+ of less than 3.5 was seen in 16 patients (9.9%). Five patients died out of 141 (3.5%). Hypoxemia Spo2 of less than 90% was seen in 3 (60%) patients who died and hypoglycaemia with blood glucose of less than 70mg/dl was seen in 2 out of 5 Patients (40%) CONCLUSIONS: low choline esterase levels less than 1.5kU/L was the most common abnormality indicating severe poisoning followed by hypoxemia. Both Hypoxemia and low acetylcholine esterase levels are bad prognostic signs and result in high mortality in organophosphorus poisoning. Keywords: Organophosphorus Poisoning, Hypoxemia, choline esterase, Hypokalaemia, Hypoglycaemia.

Abstract Background In Turku, Finland, we introduced a home oxygen treatment and app-based monitoring program for hospitalized COVID-19 patients to facilitate an early discharge during the Omicron wave. In this case series we explore the clinical parameters of patients enrolled in the program and evaluate the cost–benefit and safety issues of the program. Methods Hospitalized COVID-19 patients with marked hypoxemia but otherwise in stable condition were screened from Turku City Hospital and Turku University Hospital by treating doctors for eligibility in the program. Peripheral oxygen saturation of > 92% and breathing frequency

Xiaoli Xiang,1,2 Zhicheng Zhang,1 Ying Liu,1 Wenxuan Xu,1 Ju Gong,3 Sheng Yu,4 Lan Zhang,5 Tingwang Jiang1 1Department of Key Laboratory, Affiliated Changshu Hospital of Nantong University, Changshu, People’s Republic of China; 2Department of Ophthalmology, Affiliated Changshu Hospital of Nantong University, Changshu, People’s Republic of China; 3Department of Emergency Medicine, Affiliated Changshu Hospital of Nantong University, Changshu, People’s Republic of China; 4Department of Critical Care Medicine, Affiliated Changshu Hospital of Nantong University, Changshu, People’s Republic of China; 5Information Center, Affiliated Changshu Hospital of Nantong University, Changshu, People’s Republic of ChinaCorrespondence: Tingwang Jiang, Department of Key Laboratory, Affiliated Changshu Hospital of Nantong University, No. 68 Haiyu Nan Road, Changshu, Jiangsu Province, People’s Republic of China, Tel +86 15995921425, Fax +86 512-52277250, Email jtwgyp@163.comPurpose: To evaluate the potential relationships between serum interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α levels and occurrence of respiratory failure in patients with early-stage COVID-19 disease.Patients and Methods: We analyzed clinical characteristics, laboratory parameters, and immunoinflammatory markers in 302 patients diagnosed with SARS-CoV-2 infection who required hospitalization at Changshu Hospital of Nantong University. IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α levels in the peripheral blood of patients hospitalized five days after disease onset were measured using multiplex bead-based flow fluorescent immunoassay (MBFFI).Results: Patients with respiratory failure had higher serum IL-4 [0 (0, 0.54) pg/mL], IL-6 [40.76 (12.33, 90.28) pg/mL], IL-10 [6.65 (4.12, 11.34) pg/mL], and IL-17 [9.48 (4.31, 12.13) pg/mL] levels than patients without respiratory failure (P=0.042, P< 0.0001, P=0.012, and P=0.036, respectively). Serum IL-2, IFN-γ, and TNF-α levels were not significantly different between the two groups. The occurrence of respiratory failure was positively correlated with sex (R=0.122, P=0.034), lactic acid (R=0.193, P=0.007), white blood cell count (R=0.121, P=0.038), erythrocyte distribution width (R=0.131, P=0.024), thyrocalcitonin (R=0.280, P< 0.0001), and D-dimer levels (R=0.214, P< 0.0001) but negatively correlated with oxygen partial pressure (R=− 0.208, P=0.004), oxygen saturation (R=− 0.220, P=0.002), lymphocyte count (R=− 0.129, P=0.026), and calcium (R=− 0.152, P=0.042). Among the immunoinflammatory biomarkers, the occurrence of respiratory failure was positively correlated with IL-4 (R=− 0.117, P=0.042), IL-6 (R=0.206, P< 0.0001), IL-10 (R=0.145, P=0.012), and IL-17 (R=0.121, P=0.036) levels.Conclusion: Serum levels of pro-inflammatory cytokines IL-6 and IL-17 and anti-inflammatory cytokines IL-4 and IL-10 were significantly elevated in patients with respiratory failure and weakly positively correlated with the occurrence of respiratory failure. Further studies are required to explore these key immune mechanisms to help clinicians better manage acute complications, long-term sequelae, and possible future COVID-19 variants and be flexible in managing future epidemics and similar public health threats.Keywords: COVID-19, respiratory failure, hypoxemia, biomarkers, cytokines, disease progression

This paper summarized the effect of prone position ventilation and nursing management for a patient with respiratory distress syndrome caused by COVID-19. The compressive nursing assessment, airway management and tube fixation were conducted before using prone position ventilation for therapy. After implementation of prone position ventilation for therapy, efforts had been made to enhance the vital signs monitoring, tube maintenance, airway management, nutrition support and prevention of pressure injuries. (本文总结1例新型冠状病毒感染致呼吸窘迫综合征患者俯卧位通气法的应用效果及护理体会。操作前系统评估患者和完善物品准备, 保持气道通畅和妥善固定管道; 操作后密切监测患者生命体征, 加强导管维护、呼吸道护理和营养支持, 积极预防压力性损伤。)

Abstract Background Long-term oxygen therapy in patients with interstitial lung diseases is frequently given in order to enhance gas exchange, lessen dyspnea, and increase physical activity. Objective To evaluate how individuals with hypoxemia and interstitial lung disease respond to long-term oxygen therapy. Results Between October 2019 and July 2021, this prospective analytical (cross-sectional) study was carried out at the Assiut University Hospital’s Chest Department. Seventy ILD patients were evaluated utilizing a 6-min walk test (SMWT), the St. George respiratory questionnaire (SGRQ), MMRC, and echocardiography and follow-up was done at 1, 3, 6, and 12 months for ABG, SMWT, and MMRC. As regards echocardiography and SGRQ, a follow-up was done on admission and 1 year after starting LTOT. Significant improvement in St. George’s respiratory questionnaire score, MMRC, and EF by echocardiography was observed meanwhile PASP showed insignificant reduction. Conclusion Long-term oxygen therapy is beneficial for patients with ILD and hypoxemia. Trial registration Long-term oxygen therapy in patients with interstitial lung disease: ClinicalTrials.gov ID: NCT04089826 Registered on September 12, 2019.

Background - hyperbaric oxygen therapy (HBOT) is a clinical method of treatment with oxygen while under increased atmospheric pressure. It has been proven as an independent therapeutic factor for a number of diseases, and in the case of COVID-19, its potential as an adjuvant therapy is still being studied. Case report – in the case of a 61-year-old man with severe pneumonia resulting from infection with COVID-19 and persisting hypoxemia and dyspnea after the acute phase. Prescribed continuous oxygenation in home conditions due to deteriorating general condition and quality of life. Undertaken additional hyperbaric oxygen therapy resulting in significant improvement after the 20th session. Conclusion - the connection between HBOT and improved paraclinical and imaging indicators, in this case, suggests conclusions of a therapeutic effect of HBOT in hypoxemia as a post-COVID symptom .

Abstract Background Currently, there is limited and controversial clinical research on the correlation between sleep-disordered breathing (SDB) and dyslipidemia. This discrepancy in findings may be because studies that primarily focused on hospital-based populations may not be applicable to community-based populations. Therefore, the primary objective of this research endeavor is to scrutinize the correlation between nocturnal hypoxemia and blood lipid concentrations among adult individuals residing in the community who exhibit symptoms of SDB. Additionally, this study aimed to identify the nocturnal hypoxia parameters having the strongest correlation with this relationship. Methods This cross-sectional study collected data from The Guangdong Sleep Health Study, which included 3829 participants. Type IV sleep monitoring was employed to measure hypoxemia parameters, and lipoproteins were evaluated using fasting blood samples. To understand the association between dyslipidemia and hypoxemia parameters, a multivariable logistic regression model was used. Subgroup analyses were conducted to stratify data according to age, sex, waist circumference, and chronic diseases. Results The age of the individuals involved in the study spanned from 20 to 90 years. The average age of the participants was 56.15 ± 13.11 years. Of the total sample size, 55.7% were male. In the fully adjusted model, the meanSpO2 was negatively associated with hyperlipidemia (0.9303 [95% confidence interval 0.8719, 0.9925]). Upon conducting a nonlinearity test, the relationship between the meanSpO2 and hyperlipidemia was nonlinear. The inflection points were determined to be 95. When meanSpO2 ≥ 95%, a difference of 1 in the meanSpO2 corresponded to a 0.07 difference in the risk of hyperlipidemia. Conclusions This study revealed that higher meanSpO2 is significantly and negatively associated with hyperlipidemia in adult community residents with SDB, particularly when the meanSpO2 exceeds 95. This finding emphasizes the importance of close monitoring for dyslipidemia, which is considered an early indicator of atherosclerosis in patients with SDB who experience nocturnal hypoxia.

Abstract Background High-flow nasal oxygen (HFNO) therapy is a non-invasive respiratory support method that provides oxygen-enriched, warmed, and humidified air to respiratory-compromised patients. It is widely used in human medical care, but in veterinary medicine it is still a relatively new method. No practical guidelines exist for its use in canine pneumonia patients, although they could potentially benefit from HFNO therapy. This study aims to provide a new, safe, non-invasive, and effective treatment protocol for oxygen supplementation of non-sedated dogs with pneumonia. Methods Twenty privately owned dogs with pneumonia will receive HFNO therapy at a flow rate of 1–2 L/kg, and the fraction of inspired oxygen will be determined individually (ranging from 21% to 100%). HFNO therapy will continue as long as oxygen support is needed based on clinical evaluation. Patients will be assessed thrice daily during their hospitalisation, with measured primary outcomes including partial pressure of oxygen, oxygen saturation, respiratory rate and type, days in hospital, and survival to discharge. Discussion The proposed protocol aims to provide a practical guideline for applying HFNO to dogs hospitalised due to pneumonia. The protocol could enable more efficient and well-tolerated oxygenation than traditional methods, thus hastening recovery and improving survival of pneumonia patients.

Xiaozhen Cui,1 Zhi Cheng,2 Han Li,2 Xiaobao Zhang,2 Hengfei Luan,2 Zhibin Zhao,2 Pin Zhu2 1Department of Anesthesiology, Graduate Training Base of Lianyungang First People’s Hospital of Jinzhou Medical University, Lianyungang, Jiangsu, People’s Republic of China; 2Department of Anesthesiology, The First People’s Hospital of Lianyungang, Lianyungang, Jiangsu, People’s Republic of ChinaCorrespondence: Pin Zhu, The First People’s Hospital of Lianyungang, No. 6 East Zhenhua Road, Lianyungang, Jiangsu, People’s Republic of China, Email zhupin198348@163.comBackground: Remimazolam is a novel benzodiazepine narcotic. When used for gastrointestinal endoscopy or bronchoscopy, it provides adequate sedation and rapid recovery. However, studies on the optimal initial loading dose of remimazolam remain inadequate. Therefore, we conducted a randomized controlled clinical trial to investigate the efficacy and safety of different doses of remimazolam applied in upper gastrointestinal endoscopy.Methods: A total of 218 patients scheduled for upper gastrointestinal endoscopy were included in our trial and divided into experimental and control groups: the experimental groups were the remimazolam groups (R1 of 0.2 mg/kg, R2 of 0.3 mg/kg, and R3 of 0.4 mg/kg), and the control group was the propofol group. Following a single injection of trial drugs during the induction period, operational requirements were evaluated based on MOAA/S scores. When the sedation was successfully achieved, safety was evaluated based on the incidence of various intraoperative and postoperative adverse events.Results: The success rates of intraoperative sedation were 82% in group R1, 98% in group R2, 96% in group R3, and 100% in group P. The incidence of hypotension was lower in the remimazolam groups than in the propofol group (16%), 4% in group R1, 6% in group R2, and 6% in group R3. The incidence of postoperative vertigo was significantly higher, and sedation recovery time was prolonged in high-concentration remimazolam group.Conclusion: Satisfactory efficacy can be obtained with higher concentrations of remimazolam tosilate in patients undergoing upper gastrointestinal endoscopy with ASA grade I or II. However, as the dose is progressively increased, the incidence of adverse reactions by remimazolam tosilate are also significantly increased, such as vertigo and prolonged sedation recovery time.Trial Registration: The trial was registered prior to enrollment at the Chinese Clinical Trial Registry (ChiCTR 2000032067).Keywords: remimazolam, sedation, hypotension, hypoxemia, upper gastrointestinal endoscopy

Objective: The relationship between lipid metabolism and pneumonia in under-five children remains unclear. The aim of the study was to explore the association of several lipids, lipoproteins and apolipoproteins with the risk of childhood pneumonia, and to initially reveal the mechanisms involved. Methods: There were 1000 children with confirmed severe pneumonia and 1000 healthy controls (18–59 months old) in the study. Serum levels of several lipids, lipoproteins and apolipoproteins were measured. The occurrence of hypoxaemia and serum level of C-reactive protein were recorded. Multivariate logistic regression and spearman correlation analysis were adopted to assess the correlation between these variables to achieve the research objective. Results: First, higher triglycerides, total cholesterol, LDL cholesterol, VLDL cholesterol and apolipoprotein B levels were associated with the elevated risk of severe pneumonia (OR: 1.407, 95%CI: 1.336∼1.480; OR: 1.947, 95%CI: 1.741∼2.175; OR: 1.153, 95%CI: 1.116∼1.189; OR: 1.310, 95%CI: 1.222∼1.404; OR: 1.075, 95%CI: 1.003∼1.151). Higher HDL cholesterol and apolipoprotein A1 levels were associated with a decreased risk of the disease (OR: 0.903, 95%CI: 0.873∼0.933; OR: 0.921, 95%CI: 0.891∼0.952). Second, higher triglycerides level was associated with an increased risk of hypoxemia in these children (OR: 1.142, 95%CI: 1.072∼1.215). Third, serum HDL cholesterol level was linearly associated with C-reactive protein level in these children (ρ = -0.343, P < 0.001). Conclusion: Abnormal levels of several lipids, lipoproteins and apolipoproteins were related to severe childhood pneumonia. The findings that triglycerides and HDL cholesterol were respectively implicated in hypoxaemia and inflammation might partly explain the mechanisms linking lipid metabolism to severe pneumonia.

Abstract Background Pulmonary arteriovenous fistula is rare during pregnancy. Pulmonary arteriovenous fistula presents no pulmonary symptoms in most patients but can be exacerbated by pregnancy. If not diagnosed and treated promptly, pulmonary arteriovenous fistula can lead to respiratory failure, stroke, spontaneous hemothorax, or other fatal complications. Case presentation A 29-year-old healthy pregnant woman presented with a transient drop in blood oxygen level of unknown cause during a routine examination at 34 weeks of gestation and during a cesarean section at 38 weeks of pregnancy. The patient’s oxygen saturation quickly returned to normal and was not further investigated. On day 3 postpartum, the patient suddenly displayed slurred speech and right limb myasthenia. A head magnetic resonance imaging revealed cerebral infarction in the left basal ganglia. Subsequent computed tomography pulmonary arteriography revealed bilateral pulmonary arteriovenous fistula, which was likely the cause of cerebral infarction. The patient was transferred to the Department of Thoracic Surgery after one month of treatment and successfully underwent percutaneous embolization of pulmonary arteriovenous fistula. Conclusion Pulmonary arteriovenous fistula should not be neglected if a pregnant woman presents with transient hypoxemia and cerebral infarction. A transient decrease in pulse oxygen saturation that cannot be explained by common clinical causes can be an early warning sign of the disease. Early diagnosis and multidisciplinary management could improve the prognosis.