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Silicosis is associated with preventable but irreversible lung damage. Early quantifiable assessment of silicosis workers would promote early interventional steps to reduce health deterioration. The objectives of this study were to correlate spirometry findings and post-six-minute walk test oxygen desaturation (post-6MWT OD) in chronic simple silicosis with age, duration of silica exposure (DSE), smoking pack years (SPY), occupation, and mean pulmonary artery pressure. Based on occupational exposure to silica and radiologic confirmation of chronic simple silicosis, 104 patients (all males) were enrolled and grouped based on SPY (nil, 1-10, 11-20, and >20) and occupation (drillers and dressers). They were further investigated with spirometry, post-6MWT OD, and transthoracic echocardiography (TTE), and findings were statistically analyzed. Abnormal spirometry findings were seen in 62.5% of total cases (65/104), with the highest percentage in the >20 SPY group (84%; 21/25) and drillers (68.3%; 28/41). The post-6MWT OD was seen in 50.96% of cases (53/104) with the highest percentage in the >20 SPY group (56%; 14/25) and drillers (63.4%; 26/41). Normal and restrictive patterns were predominant among 20 SPY group. Normal, obstructive, and restrictive patterns were predominant among dressers, while mixed patterns were in drillers. Mean age and mean DSE were higher for >20 SPY group and dressers; obstructive and mixed patterns; and patients with post-6MWT OD. Pulmonary hypertension was significantly associated with the presence of abnormal spirometry patterns (69.3%; 45/65) and post-6MWT OD (79.3%; 42/53). Mean forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) was significantly lower for the >20 SPY group. Mean FEV1 had an inverse relation with SPY, and mean FVC was lower for drillers than dressers. Spirometry, post-6MWT OD, and TTE assessment give a complete overview of the cardiopulmonary exercise capacity of chronic silicosis patients and facilitate early interventions with special consideration for workers involved in machine-based mining activity.

Study objectivesObstructive sleep apnea (OSA) is accompanied by sleep fragmentation and altered sleep architecture, which can potentially hinder the glymphatic system, increasing risks for Alzheimer's disease (AD), but the status is unclear in OSA. Our aim was to investigate the glymphatic system in OSA subjects and examine the relationships between OSA disease severity, sleep symptoms, and glymphatic system indices in OSA using diffusion tensor imaging (DTI).MethodsWe acquired DTI data from 59 OSA and 62 controls using a 3.0-Tesla MRI and examined OSA disease severity and sleep symptoms with the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Diffusivity maps in the x-axis (Dxx), y-axis (Dyy), and z-axis (Dzz), as well as in x-y axis (Dxy), y-z axis (Dyz), and x-z axis (Dxz) were calculated, diffusion values for the projection and association fibers extracted, and the DTI analyses along the perivascular space (DTI-ALPS index) were performed. The glymphatic system indices were compared between groups and correlated with disease severity and sleep symptoms in OSA subjects.ResultsDzz values, derived from projection fiber areas, Dyy and Dzz values from association fiber areas, as well as ALPS and Dyzmean values were significantly reduced in OSA over controls. Significant correlations emerged between disease severity, sleep symptoms, and Dxy, Dxx, and Dzz values in OSA subjects.ConclusionOSA patients show abnormal glymphatic system function that may contribute to increased risks for AD. The findings suggest that the APLS method can be used to assess the glymphatic system in OSA patients.

Background and Objective Prior research suggests that slow wave sleep (SWS) is disrupted in people with obstructive sleep apnea (OSA). However, it was not clear whether the reduction in SWS is related to abnormal breathing or the extent of OSA as determined by the minimum oxygen saturation. Further, there is limited research on the relationship between oxygen saturation and SWS. The present study examined the relationship between SWS and minimum oxygen saturation levels in patients with OSA. Methods The sample consisted of 589 patients with OSA (mean age: 48.54 years) who completed full-night polysomnography. Results Results showed that there was a significant difference in SWS scores across three apnea-hypopnea index (AHI) groups (AHI score 5–15 for mild apnea, 16–30 for moderate apnea, and >30 for severe apnea). Lower SWS scores were observed in the severe apnea group. Additionally, results indicated that as oxygen saturation decreased, the SWS scores decreased. Conclusions Results from this study indicate that oxygen saturation significantly predicts SWS amounts. These findings suggest that interventions for low oxygen saturation could enhance the amounts of SWS. The clinical ramifications of these findings are worthy of consideration.

Pulmonary arteriovenous malformations (PAVMs) in children are rare lesions characterized by abnormal low resistance vascular structures connecting a pulmonary artery to a pulmonary vein, resulting in an intrapulmonary right-to-left shunt. The insidious onset and variable signs and symptoms make diagnosis difficult, especially in children. PAVMs can be single or multiple, congenital or acquired, and up to 47-80% of cases are associated with hereditary hemorrhagic telangiectasia (HHT).

Platypnea-orthodeoxia syndrome (POS) is an uncommon clinical condition characterized by orthostatic dyspnea and hypoxemia. The case of a female patient who manifested postoperative episodes of sudden oxygen desaturation, dyspnea, and systemic arterial hypotension following lower bilobectomy for lung adenocarcinoma was reported. After meticulous clinical investigations, the patient proved to be affected by a rare form of postural dyspnea: platypnea-orthodeoxia syndrome, a clinical disorder described in the middle of the last century. The pathophysiology was found in an intracardiac mechanism of right-to-left blood shunt, combined with lung and chest wall modification. Atrial septal defect, such as patent foramen ovale (PFO), is a common cause of platypnea-orthodeoxia syndrome; the rescue closure of PFO usually allows for an immediate and consistent improvement of the symptoms.

Abstract Background Patients with obstructive sleep apnoea (OSA), male sex, obesity, older age or hypertension are prone to hypoxemia during flexible bronchoscopy. This study investigated whether using a high-flow nasal cannula (HFNC) could reduce the incidence of oxygen desaturation during bronchoscopy under deep sedation in patients at risk of hypoxemia. Methods A total of 176 patients at risk of hypoxemia who underwent flexible bronchoscopy under deep sedation were randomly assigned to two groups: the HFNC group (humidified oxygen was supplied via a high-flow nasal cannula at a rate of 60 L/min and a concentration of 100%, n = 87) and the facemask group (oxygen was supplied via a tight-fitting facemask at a rate of 6 L/min and a concentration of 100%, n = 89). Results Oxygen desaturation occurred in 4 (4.6%) patients in the HFNC group and 26 (29.2%) patients in the facemask group (P

High‐altitude indoctrination (HAI) trains individuals to recognize symptoms of hypoxia by simulating high‐altitude conditions using normobaric (NH) or hypobaric (HH) hypoxia. Previous studies suggest that despite equivalent inspired oxygen levels, physiological differences could exist between these conditions. In particular, differences in neurophysiological responses to these conditions are not clear. Our study aimed to investigate correlations between oxygen saturation (SpO2) and neural responses in NH and HH. We recorded 5‐min of resting‐state eyes‐open electroencephalogram (EEG) and SpO2 during control, NH, and HH conditions from 13 participants. We applied a multivariate framework to characterize correlations between SpO2 and EEG measures (spectral power and multiscale entropy [MSE]), within each participant and at the group level. Participants were desaturating during the first 150 s of NH versus steadily desaturated in HH. We considered the entire time interval, first and second half intervals, separately. All the conditions were characterized by statistically significant participant‐specific patterns of EEG–SpO2 correlations. However, at the group level, the desaturation period expressed a robust pattern of these correlations across frequencies and brain locations. Specifically, the first 150 s of NH during desaturation differed significantly from the other conditions with negative absolute alpha power–SpO2 correlations and positive MSE–SpO2 correlations. Once steadily desaturated, NH and HH had no significant differences in EEG–SpO2 correlations. Our findings indicate that the desaturating phase of hypoxia is a critical period in HAI courses, which would require developing strategies for mitigating the hypoxic stimulus in a real‐world situation. [ABSTRACT FROM AUTHOR]

An analysis of the results of studies carried out by specialists of the Russian Respiratory Society over the past 15 years is given. The article also includes the main provisions set out in the III Guidelines for dyspnea. A significant part of the manual is devoted to the recent achievements in studying neurophysiological processes in the brain structures during the development of dyspnea. These achievements were driven by image-diagnosis methods. An important aspect of this series of works for the clinical practice was identifying dyspnea domains and developing the instruments to assess severity. Analysis of the data on dyspnea from the clinical practice showed a highly heterogenic clinical picture, which must be taken into account in the management of individual patients. A diagnostic algorithm for long-term follow-up of patients with dyspnea syndrome is also discussed. The attention of doctors is drawn to the features of dyspnea during COVID-19; the disproportion between the sensory perception of respiratory discomfort and the degree of oxygen desaturation is emphasized. It was concluded that in the Russian-speaking environment of patients, doctors should actively use a verbal characteristic of dyspnea the language of dyspnea.

Simple Summary: Obstructive sleep apnea (OSA) is a very prevalent disease. OSA is quite often accompanied by insomnia and the reported prevalence rate of comorbid insomnia and sleep apnea (COMISA) is 30–50%. Positive airway pressure (PAP) therapy delivered via nasal or oronasal interfaces has been established as the gold standard of therapy. Insomnia may complicate treatment of OSA and patients suffering from COMISA have reduced adherence to PAP-therapy. Respiration-coupled hypoglossal nerve stimulation (HGNS) has been established as a reliable therapeutic method in patients not tolerating PAP therapy. HGNS is associated with a significant improvement of sleep-related respiratory metrics, such as apnea-hypopnea index (AHI) and improvement of patient-reported sleep-related outcome measures. In this report, we provide evidence that HGNS therapy is also associated with a significant reduction of insomnia-related symptoms in OSA patients. Nonetheless, the preoperative severity of patient-reported insomnia symptoms is inversely correlated with the respiratory PSG-outcomes in OSA patients after HGNS therapy. In addition, we show a strong correlation between daytime sleepiness- and insomnia-related patient-reported outcomes. We suggest that insomnia should be carefully considered in future studies of excessive daytime sleepiness in OSA patients, especially those treated with HGNS. Hypoglossal nerve stimulation (HGNS) is a treatment for obstructive sleep apnea (OSA) patients with intolerance of positive airway pressure therapy. Comorbid insomnia is quite prevalent in OSA patients. We investigated the impact of insomnia and excessive daytime sleepiness (EDS) on polysomnography metrics after HGNS treatment. Data of 27 consecutive patients (9 female; mean age 55.52 ± 8.6 years) were retrospectively evaluated. Insomnia was assessed using the ISI (insomnia severity index) and EDS using the Epworth sleepiness scale (ESS). The median ISI was reduced significantly 3 months after HGNS activation (preoperative: 19; postoperative: 14; p < 0.01). Significant correlations emerged between preoperative ISI and postoperative AHI (apnea/hypopnea index; Spearman's rho = 0.4, p < 0.05), ∆ AHI (r = −0.51, p < 0.01) and ∆ ODI (oxygen desaturation index; r = −0.48, p < 0.05). ISI correlated strongly with EES both preoperatively (r = 0.46; p < 0.02) and postoperatively (r = 0.79; p < 0.001). Therefore, HGNS therapy is associated with a significant reduction of insomnia-related symptoms, in addition to the improvement in respiratory metrics in OSA. Nonetheless, the preoperative severity of patient-reported insomnia symptoms was inversely correlated with the respiratory PSG-outcomes after HGNS. Insomnia should be considered in studies of EDS in OSA patients, especially those treated with HGNS. [ABSTRACT FROM AUTHOR]

Peripartum cardiomyopathy (PPCM) is an uncommon life-threatening condition that is characterized by heart failure with reduced ejection fraction during late pregnancy or within 5 months of postpartum in the absence of other causes of heart failure. Despite advances in managing PPCM, the pathophysiology of it is still poorly understood. This article reviews the diagnostic challenges and management of PPCM, specifically highlighting a rare presentation of PPCM characterized by oxygen desaturation alone., Competing Interests: None to declare.

As the number of people travelling to altitude increases, the risk of life threatening medical emergencies also increases. It is important that we have effective strategies to minimize the risk of altitude illness. In this study, an attempt was made to investigate the combined effect of non-pharmacological (Intermittent hypoxia training; IHT) and pharmacological (acetazolamide; ACZ) intervention as a prophylactic strategy in order to minimize the risk of high altitude hypoxic related problems using rats as an animal model. Male Sprague Dawley rats were subjected to IHT for 4 h consecutively for 5 days at 12% FiO2 under normobaric conditions with and without oral ACZ administration at 25 mg/kg body weight. Validation of the intervention was performed by exposing the rats to extreme hypoxia (EH) at 8% FiO2 to further assess the effect of IHT and ACZ on hypoxic acclimatization. The principal findings of this study is that the combined effect of IHT and ACZ improves the arterial oxygenation by alterations in hemodynamics and in blood gasometry, thereby resulting into an increase in the oxygen carrying capacity of the blood with increase in SpO2 (peripheral oxygen saturation). The present study showed that the combined effect of IHT with ACZ could be refined as a prophylactic measure for better outcomes during altitude ascent and rapid altitude acclimatization rather than IHT or ACZ alone.

Background: Although Remdesivir has been evaluated for the treatment of coronavirus disease 2019 (COVID-19), few study has yet shown effective mortality reduction. It might be because, in almost all those studies, remdesivir therapy was started beyond 7th days from the onset of symptoms when the active viral replications have already gone. Methods: This study reviewed the effectiveness of early remdesivir therapy during viral phase of COVID-19 and safety of its administration at home or community care during the outbreak of COVID-19 from July to September 2021 in Myanmar. We retrospectively reviewed clinical records of 204 high risk COVID-19 patients who had received remdesivir therapy within 7 days from the onset of illness and before oxygen desaturation. Findings: All patients received remdesivir therapy according to standard five days course of 200 mg loading dose on day 1, followed by 100 mg daily for up to 4 additional days. Out of 204 patients, 60.75% (124/204) were aged 60 years and above with comorbidity; 21.1% (43/204) aged under 60 years with comorbidity and 18.1% (37/204) were aged more than 60 years old without comorbidity. The patients who received RDSV therapy within 1-4 days and within 5-7 days were 50.5% (103/204) and 49.5% (101/204) respectively. All patients survived to 21 days without ICU admission or mechanical ventilation. Eighty six percent of patients had no hypoxia and only five percent had moderate to severe hypoxia, requiring oxygen. Those who received RDSV therapy within 1 to 4 days from the onset of symptoms had significantly lower rate of hypoxia compared to those who received remdesivir therapy on 5 to 7 days. After RDSV therapy, increased lymphocyte count and decreased CPR were observed in 74.5% (152/204) and 52.9% (108/204) of the patients respectively. There was no report of major adverse events. Conclusion: Remdesivir, if given within first 4 days from the onset of symptoms, is the most effective strategy for prevention of oxygen desaturation, further progression of COVID-19 and death although it is still beneficial if given later, days 5 to 7. It is a safe drug to be prescribed in hospital at home care. It may be cost-benefit if high-risk group of patients with COVID-19 were selected for early remdesivir therapy in the community.

Background: Patients admitted with chronic respiratory diseases (CRDs) find it difficult to return to their day-to-day activities postdischarge due to muscle dysfunction and cardiorespiratory load. The Timed Up and Go (TUG) test is extensively used for predicting falls; however, it is underutilized to assess the cardiorespiratory load. The study was designed to assess the time in seconds, the cardiorespiratory load including desaturation with TUG, and also the correlation if any between TUG time in seconds with oxygen saturation (SpO2) and Barthel Index score. Materials and Methods: Hundred and twenty-eight patients admitted with CRDs in the age range of 40–70 years were included. Activities of daily living were scored on Barthel Index. TUG was carried out and changes in cardiorespiratory parameters, i.e., heart rate (HR), blood pressure (BP), respiratory rate (RR), and SpO2 were noted. Results: All cardiorespiratory parameters HR, BP, and RR showed a statistically significant change (P < 0.0001). There was a significant drop in SpO2 (mean 9%) post TUG. There was a significant but weak inverse correlation (r = 0.5069) observed between TUG in seconds and SpO2 at rest. There was no correlation between TUG and Barthel score. The mean time for TUG was 16.73 ± 3.11 s indicating a moderate risk of fall. Conclusions: TUG leads to a significant change in cardiorespiratory parameters including SpO2. It can be used as a test to assess activity tolerance and the need for oxygen supplementation.

Background: Patients with obstructive sleep apnoea (OSA), male sex, obesity, older age or hypertension are prone to hypoxemia during flexible bronchoscopy. This study investigated whether using a high-flow nasal cannula (HFNC) could reduce the incidence of oxygen desaturation during bronchoscopy under deep sedation in patients at risk of hypoxemia.Methods: A total of 176 patients at risk of hypoxemia who underwent flexible bronchoscopy under deep sedation were randomly assigned to two groups: the HFNC group (humidified oxygen was supplied via a high-flow nasal cannula at a rate of 60 L/min and a concentration of 100%, n = 87) and the facemask group (oxygen was supplied via a tight-fitting facemask at a rate of 6 L/min and a concentration of 100%, n = 89).Results: Oxygen desaturation occurred in 4 (4.6%) patients in the HFNC group and 26 (29.2%) patients in the facemask group (P < 0.001). The facemask group required more jaw thrust manoeuvres than the HFNC group (43[48.3%] vs. 5[5.7%], P < 0.001). 8 patients (9.0%) in the facemask group and none in the HFNC group required bag-mask ventilation (P = 0.012).Conclusion: The use of an HFNC can reduce the incidence of oxygen desaturation and the requirement for airway intervention in patients at risk of hypoxemia during flexible bronchoscopy under deep sedation.Trial Registration: www.chiCTR.org.cn Identifier: ChiCTR2100044105. Registered 11/03/2021. [ABSTRACT FROM AUTHOR]

Abstract Background Preoxygenation and application of apneic oxygenation are standard to prevent patients from desaturation e.g. during emergency intubation. The time before desaturation occurs can be prolonged by applying high flow oxygen into the airway. Aim of this study was to scientifically assess the flow that is necessary to avoid nitrogen entering the airway of a manikin model during application of pure oxygen via high flow nasal oxygen. Methods We measured oxygen content over a 20-min observation period for each method in a preoxygenated test lung applied to a human manikin, allowing either room air entering the airway in control group, or applying pure oxygen via high flow nasal oxygen at flows of 10, 20, 40, 60 and 80 L/min via nasal cannula in the other groups. Our formal hypothesis was that there would be no difference in oxygen fraction decrease between the groups. Results Oxygen content in the test lung dropped from 97 ± 1% at baseline in all groups to 43 ± 1% in the control group (p

Background: Obstructive sleep apnea (OSA) is associated with cerebral small vessel disease (CSVD). Nonetheless, whether OSA-risk determined by a simple screening questionnaire or indices quantifying nocturnal hypoxemia other than the conventional apnea–hypopnea index (AHI) by the home sleep apnea test (HSAT) associated with CSVD burden remains uncertain. Methods: From 2018 to 2021, we recruited patients with transient ischemic attack (TIA)/minor stroke from the Queen Mary Hospital Acute Stroke Unit and TIA/Stroke Outpatient Clinics. Logistic regression models were applied to determine the association of baseline OSA-risk (on STOP-BANG questionnaire) or HSAT-derived indices quantifying nocturnal hypoxemia with global burden/individual markers of CSVD on MRI. Indices included oxygen desaturation (≥3%) index (ODI), minimum oxygen saturation (SpO2), percentage of total sleep time with an oxygen saturation <90% (CT90%), and desaturation duration (≥3%, DesDur). Results: In 283 patients with TIA/minor stroke (mean age 65 years, 64% men), OSA-risk was significantly associated with total CSVD score (multivariate-adjusted odds ratio: 1.23, 95% confidence interval 1.01–1.51), presence of lacunes [1.39 (1.09–1.79)] and burden of basal ganglia PVSs [1.32 (1.06–1.67)]. In 85/283 patients who completed HSAT, neither AHI, minimum SpO2 nor CT90% was associated with CSVD burden. Nonetheless, ODI and DesDur remained significantly associated with total CSVD score after covariate adjustment: ODI [1.04 (1.01–1.07)] and DesDur [1.04 (1.01–1.08)]. Conclusion: In patients with TIA/minor stroke, high OSA-risk was associated with a greater CSVD burden. Oxygen desaturation indices (ODI and DesDur) rather than AHI were independently associated with global CSVD burden, indicating that longer and more severe desaturations may contribute to the pathogenesis of CSVD. [ABSTRACT FROM AUTHOR]

Background: Although Remdesivir has been evaluated for the treatment of coronavirus disease 2019 (COVID-19), few study has yet shown effective mortality reduction. It might be because, in almost all those studies, remdesivir therapy was started beyond 7th days from the onset of symptoms when the active viral replications have already gone. Methods: This study reviewed the effectiveness of early remdesivir therapy during viral phase of COVID-19 and safety of its administration at home or community care during the outbreak of COVID-19 from July to September 2021 in Myanmar. We retrospectively reviewed clinical records of 204 high risk COVID-19 patients who had received remdesivir therapy within 7 days from the onset of illness and before oxygen desaturation. Findings: All patients received remdesivir therapy according to standard five days course of 200 mg loading dose on day 1, followed by 100 mg daily for up to 4 additional days. Out of 204 patients, 60.75% (124/204) were aged 60 years and above with comorbidity; 21.1% (43/204) aged under 60 years with comorbidity and 18.1% (37/204) were aged more than 60 years old without comorbidity. The patients who received RDSV therapy within 1-4 days and within 5-7 days were 50.5% (103/204) and 49.5% (101/204) respectively. All patients survived to 21 days without ICU admission or mechanical ventilation. Eighty six percent of patients had no hypoxia and only five percent had moderate to severe hypoxia, requiring oxygen. Those who received RDSV therapy within 1 to 4 days from the onset of symptoms had significantly lower rate of hypoxia compared to those who received remdesivir therapy on 5 to 7 days. After RDSV therapy, increased lymphocyte count and decreased CPR were observed in 74.5% (152/204) and 52.9% (108/204) of the patients respectively. There was no report of major adverse events. Conclusion: Remdesivir, if given within first 4 days from the onset of symptoms, is the most effective strategy for prevention of oxygen desaturation, further progression of COVID-19 and death although it is still beneficial if given later, days 5 to 7. It is a safe drug to be prescribed in hospital at home care. It may be cost-benefit if high-risk group of patients with COVID-19 were selected for early remdesivir therapy in the community. [ABSTRACT FROM AUTHOR]

Abstract Background Failed airway management is the major contributor for anaesthesia-related morbidity and mortality. Cannot-intubate-cannot-ventilate scenarios are the most critical emergency in airway management, and belong to the worst imaginable scenarios in an anaesthetist’s life. In such situations, apnoeic oxygenation might be useful to avoid hypoxaemia. Anaesthesia guidelines recommend careful preoxygenation and application of high flow oxygen in difficult intubation scenarios to prevent episodes of deoxygenation. In this study, we evaluated the decrease in oxygen concentration in a model when using different strategies of oxygenation: using a special oxygenation laryngoscope, nasal oxygen, nasal high flow oxygen, and control. Methods In this experimental study we compared no oxygen application as a control, standard pure oxygen application of 10 l·min− 1 via nasal cannula, high flow 90% oxygen application at 20 l·min− 1 using a special nasal high flow device, and pure oxygen application via our oxygenation laryngoscope at 10 l·min− 1. We preoxygenated a simulation lung to 97% oxygen concentration and connected this to the trachea of a manikin model simulating apnoeic oxygenation. Decrease in oxygen concentration in the simulation lung was measured continuously for 20 min. Results Oxygen concentration in the simulation lung dropped from 97 ± 1% at baseline to 40 ± 1% in the no oxygen group, to 80 ± 1% in the standard nasal oxygen group, and to 73 ± 2% in the high flow nasal oxygenation group. However, it remained at 96 ± 0% in the oxygenation laryngoscope group (p

Background: Measurement of oxygen saturation (SpO2) during the 6 minute walk test (6MWT) could be impacted by the measurement site. Aims: To compare SpO2 and heart rate (HR) between forehead and finger sensors during the 6MWT. Sensor readings were also to be compared for signal quality and with capillary blood gas (CBG) pre and post 6MWT. Method: 80 subjects with pulmonary vascular disease (PVD) and/or interstitial lung disease (ILD) performed the 6MWT. Pulse oximetry was recorded at 30 s intervals. CBG was taken pre and post 6MWT to determine capillary oxygen saturation (SCO2). Results: The forehead sensor recorded higher values for SpO2 (p < 0.001) and HR (p < 0.01) compared with the finger sensor during the 6MWT. For both sensors, the demonstrated bias compared to CBG post 6MWT was higher and more variable in subjects who desaturated. During the 6MWT there was a higher occurrence (p < 0.001) of poor signal quality in the finger sensor compared with the forehead sensor. Conclusion: This study suggests that the sensor site can impact pulse oximetry readings. The variance in bias suggests pulse oximetry may not accurately reflect SCO2 measurements particularly in subjects who desaturate during 6MWT. [ABSTRACT FROM AUTHOR]

Abstract Background Sedation during elective fiberoptic intubation for difficult airway can cause respiratory depression, apnea and periods of desaturation. During apneic episodes, hypoxemia can be prevented by insufflation of oxygen in the deep laryngeal space. The aim of this study was to evaluate an oropharyngeal oxygenation device (OOD) designed for deep laryngeal insufflation during fiberoptic intubation. Methods The OOD is split in the front to form a path for the bronchoscope. An external lumen delivers oxygen in the deep laryngeal space. In this experimental study, air application (as control group), oxygen application via nasal prongs, oxygen application via the OOD, and oxygen application via the working channel of a bronchoscope were compared in a technical simulation. In a preoxygenated test lung of a manikin, decrease of the oxygen saturation was measured over 20 min for each method. Results Oxygen saturation in the test lung dropped from 97 ± 1% (baseline in all groups) to 58 ± 3% in the control-group (p

Abstract Background We developed a Vital-signs-integrated Patient-assisted Intravenous opioid Analgesia (VPIA) analgesic infusion pump, a closed-loop vital signs monitoring and drug delivery system which embodied in a novel algorithm that took into account patients’ vital signs (oxygen saturation, heart rate). The system aimed to allow responsive titration of personalized pain relief to optimize pain relief and reduce the risk of respiratory depression. Moreover, the system would be important to enable continuous monitoring of patients during delivery of opioid analgesia. Methods Nineteen patients who underwent elective gynecological surgery with postoperative patient controlled analgesia (PCA) with morphine were recruited. The subjects were followed up from their admission to the recovery room/ ward for at least 24 h until assessment of patient satisfaction on the VPIA analgesic infusion pump. Results The primary outcome measure of incidence of oxygen desaturation showed all patients had at least one episode of oxygen desaturation (

BackgroundDuring early skin-to-skin contact (ESSC), alterations in peripheral oxygen saturation (SpO2) and heart rate (HR) have been frequently observed.ObjectivesThis study aimed to determine the incidence of cardiorespiratory events (CREs) during ESSC in healthy term newborns (HTNs) and estimate the association of maternal and neonatal prognostic factors with the risk of CREs.MethodsA pooled analysis of the cohort from a clinical trial involving healthy mother–child dyads during ESSC was performed. Pulse oximetry was employed to continuously monitor SpO2 and HR within 2 h after birth. The individual and combined prognostic relevance of the demographic and clinical characteristics of dyads for the occurrence of a CRE (SpO2 180 bpm) was analyzed through logistic regression models.ResultsOf the 254 children assessed, 169 [66.5%; 95% confidence interval (95% CI), 60.5–72.5%] had at least one CRE. The characteristics that increased the risk of CRE were maternal age ≥35 years (odds ratio, 2.21; 95% CI, 1.19–4.09), primiparity (1.96; 1.03–3.72), gestational body mass index (BMI) >25 kg/m2 (1.92; 1.05–3.53), and birth time between 09:00 p.m. and 08:59 a.m. (2.47; 1.02–5.97).ConclusionCREs were more frequent in HTNs born during nighttime and in HTNs born to first-time mothers, mothers ≥35 years, and mothers with a gestational BMI >25 kg/m2. These predictor variables can be determined during childbirth. Identification of neonates at higher risk of developing CREs would allow for closer surveillance during ESSC.

Study ObjectivesObstructive sleep apnea (OSA) is accompanied by sleep fragmentation and altered sleep architecture, which can potentially hinder the glymphatic system, increasing risks for Alzheimer’s disease (AD), but the status is unclear in OSA. Our aim was to investigate the glymphatic system in OSA subjects and examine the relationships between OSA disease severity, sleep symptoms, and glymphatic system indices in OSA using diffusion tensor imaging (DTI).MethodsWe acquired DTI data from 59 OSA and 62 controls using a 3.0-Tesla MRI and examined OSA disease severity and sleep symptoms with the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Diffusivity maps in the x-axis (Dxx), y-axis (Dyy), and z-axis (Dzz), as well as in x-y axis (Dxy), y-z axis (Dyz), and x-z axis (Dxz) were calculated, diffusion values for the projection and association fibers extracted, and the DTI analyses along the perivascular space (DTI-ALPS index) were performed. The glymphatic system indices were compared between groups and correlated with disease severity and sleep symptoms in OSA subjects.ResultsDzz values, derived from projection fiber areas, Dyy and Dzz values from association fiber areas, as well as ALPS and Dyzmean values were significantly reduced in OSA over controls. Significant correlations emerged between disease severity, sleep symptoms, and Dxy, Dxx, and Dzz values in OSA subjects.ConclusionOSA patients show abnormal glymphatic system function that may contribute to increased risks for AD. The findings suggest that the APLS method can be used to assess the glymphatic system in OSA patients.

Background: Preoxygenation and application of apneic oxygenation are standard to prevent patients from desaturation e.g. during emergency intubation. The time before desaturation occurs can be prolonged by applying high flow oxygen into the airway. Aim of this study was to scientifically assess the flow that is necessary to avoid nitrogen entering the airway of a manikin model during application of pure oxygen via high flow nasal oxygen. Methods: We measured oxygen content over a 20-min observation period for each method in a preoxygenated test lung applied to a human manikin, allowing either room air entering the airway in control group, or applying pure oxygen via high flow nasal oxygen at flows of 10, 20, 40, 60 and 80 L/min via nasal cannula in the other groups. Our formal hypothesis was that there would be no difference in oxygen fraction decrease between the groups. Results: Oxygen content in the test lung dropped from 97 ± 1% at baseline in all groups to 43 ± 1% in the control group (p < 0.001 compared to all other groups), to 92 ± 1% in the 10 L/min group, 92 ± 1% in the 20 L/min group, 90 ± 1% in the 40 L/min group, 89 ± 0% in the 60 L/min group and 87 ± 0% in the 80 L/min group. Apart from comparisons 10 l/ min vs. 20 L/min group (p =.715) and 10/L/min vs. 40 L/min group (p =.018), p was < 0.009 for all other comparisons. Conclusions: Simulating apneic oxygenation in a preoxygenated manikin connected to a test lung over 20 min by applying high flow nasal oxygen resulted in the highest oxygen content at a flow of 10 L/min; higher flows resulted in slightly decreased oxygen percentages in the test lung. [ABSTRACT FROM AUTHOR]

Objective: The primary objective of the present cross-sectional study is to evaluate the semantic language abilities of patients with Obstructive Sleep Apnea Syndrome (OSAS) compared to normative data. Secondary objectives are to examine the effects of OSAS comorbidities on language test performance. Method: 118 adult patients suffering from OSAS were assessed using standardized tests (Boston Naming Test, the Peabody Picture Vocabulary Test and the Verbal Fluency Test). Results: Compared to normative standards, the OSAS group (age and education adjusted mean) scored significantly lower on all tests (p < 0.01). The OSAS group also included a significantly higher percentage of persons scoring below the 5th percentile of the normative distribution on the four tests (p < 0.01). The Apnea/Hypopnea Index, O2 Desaturation index, SaO2 <85% (min) and SaO2 <75% (min) were significantly associated with language test scores (p < 0.05). Moreover, higher Apnea–Hypopnea Index score and night-time oxygen desaturation were associated with reduced phonemic and semantic fluency performance only among patients with a history of hypertension and hypercholesterolemia (p < 0.05). The moderating effect of diabetes and cardiovascular disease on the association between OSAS severity indices and test scores did not reach significance (p > 0.6). Conclusions: Results suggest that the severity of semantic language impairments in patients with OSAS is associated with the severity of the disease and intensified by common medical comorbidities (hypertension and hypercholesterolemia). [ABSTRACT FROM AUTHOR]

Background: We examined the association between emergent postoperative tracheal intubation and the use of supraglottic airway devices (SGAs) vs tracheal tubes.Methods: We included data from adult noncardiac surgical cases under general anaesthesia between 2008 and 2018. We only included cases (n=59 991) in which both airways were deemed to be feasible options. Multivariable logistic regression, instrumental variable analysis, propensity matching, and mediation analysis were used.Results: Use of a tracheal tube was associated with a higher risk of emergent postoperative intubation (adjusted absolute risk difference [ARD]=0.80%; 95% confidence interval (CI), 0.64-0.97; P<0.001), and a higher risk of post-extubation hypoxaemia (ARD=3.9%; 95% CI, 3.4-4.4; P<0.001). The effect was modified by the use of non-depolarising neuromuscular blocking agents (NMBAs); mediation analyses revealed that 28.9% (95% CI, 14.4-43.4%; P<0.001) of the main effect was attributable to NMBA. Airway management modified the association of NMBA and risk of emergent postoperative intubation (Pinteraction=0.02). Patients managed with an SGA had higher odds of NMBA-associated reintubation compared to patients managed with a tracheal tube (adjusted odds ratio [aOR]=3.65, 95% CI, 1.99-6.67 vs aOR=1.68, 95% CI, 1.29-2.18 [P<0.001], respectively).Conclusions: In patients undergoing procedures under general anaesthesia that could be managed with either SGA or tracheal tube, use of an SGA was associated with lower risk of emergent postoperative intubation. The effect can partly be explained by use of NMBAs. Use of NMBAs in patients with an SGA appears to increase the risk of emergent postoperative intubation. [ABSTRACT FROM AUTHOR]

Objectives: Children with untreated sleep-disordered breathing (SDB) have impaired intellectual ability and behavioral effects. Timely treatment of SDB by adenotonsillectomy (AT) may prevent this morbidity. This study was designed to assess the prevalence of neurocognitive and behavioral dysfunction in Indian children with SDB and to evaluate the impact of AT. Methods: Children recruited underwent diagnostic polysomnography (PSG), a detailed neurocognitive and behavioral assessment using a battery of validated instruments – the Malin's Intelligence Scale (MIS) for Indian children, Modified Wisconsin's Card Sorting Test, Parent Conners' Scale, and the Childhood Behavior Checklist (6–18). These children then underwent AT and subsequent reassessment at 3 and 6 months. Results: Neurocognitive impairment was common among the 33 enrolled children (mean age 9 [±2.97] years; 78.8% males). There was a significant correlation between the lowest O2saturation and the “categories completed” (r = -0.379; P = 0.029); and the lowest O2saturation and the “failure to maintain sets” (r = 0.386; P = 0.026) of the Modified Wisconsin's Card Sorting Test. Postsurgery, although apnea–hypopnea index (AHI) significantly decreased after surgery, 15 children still had SDB. Mean scores of most of the tested neurocognitive and behavioral domains showed improvement, although residual deficits were prevalent even after 6 months. Patients with a baseline AHI >5/h and those who had complete resolution of SDB (postoperative AHI

Introduction Pulmonary hypertension patients develop hemodynamic changes that contribute to the symptoms, especially during exertion. The inability of the heart to increase cardiac output and the ventilation/perfusion mismatch, may explain the presence of exercise oxygen desaturation. Rationale The rational is to study the relation of exercise oxygen desaturation with the severity of pulmonary arterial hypertension (PAH) group I. Patients and methods Thirty-nine patients diagnosed as having PAH group I were included in the study; 30 (76.9%) female patients and nine (23.1%) male patients. Six-minute walk distance (6MWD) was performed as a marker for the risk of mortality. The degree of desaturation was calculated. The disease severity is assessed in terms of right atrial pressure (RAP), oxygen saturation of the mixed venous blood, cardiac output, mean pulmonary artery pressure, and peripheral vascular resistance. Results The mean age was 37.74±10.58; the patients were presented within functional classes II and III. The mean 6MWD (264.95±87.32), RAP (10.87±6.22), and oxygen saturation of the mixed venous blood (58.67±8.13) denote moderate risk of mortality in 1 year of 5–10%. The mean degree of desaturation is 3.72%, and the basal oxygen saturation is 94.44%. There was a statistically significant negative correlation between the 6MWD and RAP, and positive correlation between 6MWD and arterial oxygen saturation, as well as between the mean pulmonary artery pressure and degree of desaturation. Conclusion Exercise desaturation is an important factor in the development and deterioration of PAH, yet it has no significant correlation with the parameters of the disease severity used.

Background: Failed airway management is the major contributor for anaesthesia-related morbidity and mortality. Cannot-intubate-cannot-ventilate scenarios are the most critical emergency in airway management, and belong to the worst imaginable scenarios in an anaesthetist's life. In such situations, apnoeic oxygenation might be useful to avoid hypoxaemia. Anaesthesia guidelines recommend careful preoxygenation and application of high flow oxygen in difficult intubation scenarios to prevent episodes of deoxygenation. In this study, we evaluated the decrease in oxygen concentration in a model when using different strategies of oxygenation: using a special oxygenation laryngoscope, nasal oxygen, nasal high flow oxygen, and control.Methods: In this experimental study we compared no oxygen application as a control, standard pure oxygen application of 10 l·min- 1 via nasal cannula, high flow 90% oxygen application at 20 l·min- 1 using a special nasal high flow device, and pure oxygen application via our oxygenation laryngoscope at 10 l·min- 1. We preoxygenated a simulation lung to 97% oxygen concentration and connected this to the trachea of a manikin model simulating apnoeic oxygenation. Decrease in oxygen concentration in the simulation lung was measured continuously for 20 min.Results: Oxygen concentration in the simulation lung dropped from 97 ± 1% at baseline to 40 ± 1% in the no oxygen group, to 80 ± 1% in the standard nasal oxygen group, and to 73 ± 2% in the high flow nasal oxygenation group. However, it remained at 96 ± 0% in the oxygenation laryngoscope group (p < 0.001 between all groups).Conclusions: In this technical simulation, oxygenation via oxygenation laryngoscope was more effective than standard oxygen insufflation via nasal cannula, which was more effective than nasal high flow insufflation of 90% oxygen. [ABSTRACT FROM AUTHOR]

Background: Sedation during elective fiberoptic intubation for difficult airway can cause respiratory depression, apnea and periods of desaturation. During apneic episodes, hypoxemia can be prevented by insufflation of oxygen in the deep laryngeal space. The aim of this study was to evaluate an oropharyngeal oxygenation device (OOD) designed for deep laryngeal insufflation during fiberoptic intubation. Methods: The OOD is split in the front to form a path for the bronchoscope. An external lumen delivers oxygen in the deep laryngeal space. In this experimental study, air application (as control group), oxygen application via nasal prongs, oxygen application via the OOD, and oxygen application via the working channel of a bronchoscope were compared in a technical simulation. In a preoxygenated test lung of a manikin, decrease of the oxygen saturation was measured over 20 min for each method. Results: Oxygen saturation in the test lung dropped from 97 ± 1% (baseline in all groups) to 58 ± 3% in the control-group (p < 0.001 compared to all other groups) and to 78 ± 1% in the nasal prong group (p < 0.001 compared to all other groups). Oxygen saturation remained at 95 ± 2% in both the OOD group and the bronchoscopy group (p = 0.451 between those two groups). Conclusion: Simulating apneic laryngeal oxygenation in a preoxygenated manikin, both oxygen insufflation via the OOD and the bronchoscope kept oxygen saturation in the test lung at 95% over 20 min. Both methods significantly were more effective than oxygen insufflation via nasal prongs. [ABSTRACT FROM AUTHOR]

Introduction: The STOP-Bang questionnaire has been useful to identify patients with high risk of oxygen desaturation, among others postoperative complications. General Objective: Determine the association of oxygen desaturation with the high STOP-Bang questionnaire applied in preanesthetic consultation. Materials and methods: Observational, retrospective, longitudinal design. It was performed in the Navy Medical Center. The study included patients over 18 years old divided into two groups under general anesthesia: the STOP-Bang score < 3 and =3. The patients were assessed with the STOP-Bang questionnaire, sensitivity for moderate 93%. Analyzed through descriptive statistic-study and Xi2, significance p<0.05. And statistic package SPSS v24.0. Results: A sample of 121 patients were programmed for surgery under general anesthesia, The STOP-Bang scores high 85 and low 36. Patients over 50 years old in 49 (58%) high STOP-Bang score; atrial fibrillation 17 (17.6%) high STOP-Bang and 0% low STOP-Bang scores. Hypertensive patients of 52 (61%) high STOP-Bang and 5 (14%) low scores, p<0.000. Oxygen desaturation in 18 (21%) STOP-Bang high and, 1 (3%) low scores, p<0.012 OR 9.4 (IC 95% 1.2-73.3). Conclusion: Higher scores of STOP-Bang were associated to oxygen desaturation and cardiovascular disease risk. [ABSTRACT FROM AUTHOR]

Background: We developed a Vital-signs-integrated Patient-assisted Intravenous opioid Analgesia (VPIA) analgesic infusion pump, a closed-loop vital signs monitoring and drug delivery system which embodied in a novel algorithm that took into account patients' vital signs (oxygen saturation, heart rate). The system aimed to allow responsive titration of personalized pain relief to optimize pain relief and reduce the risk of respiratory depression. Moreover, the system would be important to enable continuous monitoring of patients during delivery of opioid analgesia. Methods: Nineteen patients who underwent elective gynecological surgery with postoperative patient controlled analgesia (PCA) with morphine were recruited. The subjects were followed up from their admission to the recovery room/ ward for at least 24 h until assessment of patient satisfaction on the VPIA analgesic infusion pump. Results: The primary outcome measure of incidence of oxygen desaturation showed all patients had at least one episode of oxygen desaturation (< 95%) during the study period. Only 6 (31.6%) patients had oxygen desaturation that persisted for more than 5 min. The median percentage time spent during treatment that oxygen saturation fell below 95% was 1.9%. Fourteen (73.7%) out of 19 patients encountered safety pause, due to transient oxygen desaturation or bradycardia. The patients' median [IQR] pain scores at rest and at movement after post-op 24 h were 0.0 [2.0] and 3.0 [2.0], respectively. The average morphine consumption in the first 24 h was 12.5 ± 7.1 mg. All patients were satisfied with their experience with the VPIA analgesic infusion pump. Conclusions: The use of VPIA analgesic infusion pump, when integrated with continuous vital signs monitor and variable lockout algorithm, was able to provide pain relief with good patient satisfaction. Trial registration: This study was registered on clinicaltrials.gov registry (NCT02804022) on 28 Feb 2016. [ABSTRACT FROM AUTHOR]

Obstructive sleep apnea (OSA) is a common sleep disorder, and continuous positive airway pressure (CPAP) is the most effective treatment. Poor adherence is one of the major challenges in CPAP therapy. The recent boom of wearable optical sensors measuring oxygen saturation makes at-home multiple-night CPAP titrations possible, which may essentially improve the adherence of CPAP therapy by optimizing its pressure in a real-life setting economically. We tested whether the oxygen desaturations (ODs) measured in the arm muscle (arm_OD) by gold-standard frequency-domain multi-distance near-infrared spectroscopy (FDMD-NIRS) change quantitatively with titrated CPAP pressures in OSA patients together with polysomnography. We found that the arm_OD (2.08 ± 1.23%, mean ± standard deviation) was significantly smaller (p-value < 0.0001) than the fingertip OD (finger_OD) (4.46 ± 2.37%) measured by a polysomnography pulse oximeter. Linear mixed-effects models suggested that CPAP pressure was a significant predictor for finger_OD but not for arm_OD. Since FDMD-NIRS measures a mixture of arterial and venous OD, whereas a fingertip pulse oximeter measures arterial OD, our results of no association between arm_OD and finger_OD indicate that the arm_OD mainly represented venous desaturation. Arm_OD measured by optical sensors used for wearables may not be a suitable indicator of the CPAP titration effectiveness.

Abstract Background Fibrotic interstitial lung diseases (ILDs) are chronic and often progressive conditions resulting in substantial morbidity and mortality. Shortness of breath, a symptom often linked to oxygen desaturation on exertion, is tightly linked to worsening quality of life in these patients. Although ambulatory oxygen is used empirically in their treatment, there are no ILD-specific guidelines on its use. To our knowledge, no studies are available on the effects of ambulatory oxygen on day-to-day life in patients with ILD. Methods/design Ambulatory oxygen in fibrotic lung disease (AmbOx) is a multicentre, randomised controlled crossover trial (RCT) funded by the Research for Patient Benefit Programme of the National Institute for Health Research. The trial will compare ambulatory oxygen used during daily activities with no ambulatory oxygen in patients with fibrotic lung disease whose oxygen saturation (SaO2) is ≥94% at rest, but drops to ≤88% on a 6-min Walk Test. The randomised controlled trial (RCT) will evaluate the effects on health status (measured by the King’s Brief ILD Questionnaire: K-BILD) of ambulatory oxygen used at home, at an optimal flow rate determined by titration at screening visit, and administered for a 2-week period, compared to 2 weeks off oxygen. Key secondary outcomes will include breathlessness on activity scores, as measured by the University of California San Diego Shortness of Breath Questionnaire, global patient assessment of change scores, as well as quality of life scores (St George’s Respiratory Questionnaire), anxiety and depression scores (Hospital Anxiety and Depression Scale), activity markers measured by SenseWear Armbands, pulse oximetry measurements, patient-reported daily activities, patient- and oxygen company-reported oxygen cylinder use. The study also includes a qualitative component and will explore in interviews patients’ experiences of the use of a portable oxygen supply and trial participation in a subgroup of 20 patients and carers. Discussion This is the first RCT of the effects of ambulatory oxygen during daily life on health status and breathlessness in fibrotic lung disease. The results generated should provide the basis for setting up ILD-specific guidelines for the use of ambulatory oxygen. Trial registration National Clinical Trials Registry, identifier: NCT02286063 . Registered on 8 October 2014 (retrospectively registered).

Objectives: Children with untreated sleep‑disordered breathing (SDB) have impaired intellectual ability and behavioral effects. Timely treatment of SDB by adenotonsillectomy (AT) may prevent this morbidity. This study was designed to assess the prevalence of neurocognitive and behavioral dysfunction in Indian children with SDB and to evaluate the impact of AT. Methods: Children recruited underwent diagnostic polysomnography (PSG), a detailed neurocognitive and behavioral assessment using a battery of validated instruments – the Malin’s Intelligence Scale (MIS) for Indian children, Modified Wisconsin’s Card Sorting Test, Parent Conners’ Scale, and the Childhood Behavior Checklist (6–18). These children then underwent AT and subsequent reassessment at 3 and 6 months. Results: Neurocognitive impairment was common among the 33 enrolled children (mean age 9 [±2.97] years; 78.8% males). There was a significant correlation between the lowest O2 saturation and the “categories completed” (r = -0.379; P = 0.029); and the lowest O2 saturation and the “failure to maintain sets” (r = 0.386; P = 0.026) of the Modified Wisconsin’s Card Sorting Test. Postsurgery, although apnea–hypopnea index (AHI) significantly decreased after surgery, 15 children still had SDB. Mean scores of most of the tested neurocognitive and behavioral domains showed improvement, although residual deficits were prevalent even after 6 months. Patients with a baseline AHI >5/h and those who had complete resolution of SDB (postoperative AHI <1/h) showed improvement in more subscales than patients with baseline AHI < 5/h and patients with incomplete resolution of SDB. Conclusion: The decreased neurocognitive performance related to SDB may be a result of hypoxemia, rather than the frequency of SDB events. Despite AT, residual disease is common and such patients may require further treatment. [ABSTRACT FROM AUTHOR]

Sleep apnea has been related to brain changes such as atrophy. However, which component of sleep apnea, the apnea-hypopnea index (AHI), nocturnal oxygen desaturation or arousals, can explain this association is unclear. In this large population-based study (n=681, mean age 62.1 years), we investigated the associations of AHI, nocturnal oxygen desaturation and arousals with global and regional gray matter and white matter volumes and with white matter lesion volumes. All participants underwent one night of polysomnography and MRI scanning of their brain. Gray matter, white matter and white matter lesion volumes adjusted for intracranial volume were studied as markers of brain atrophy. Nocturnal oxygen desaturation was related to whole brain white matter atrophy independent of covariates (multivariable adjusted B=−8.3, 95% CI=−16.7; −0.02). This association was most prominently reflected in the association between more oxygen desaturation and a smaller white matter parietal volume (B=−3.95 ml, 95% CI=−6.02; −1.88). Furthermore, oxygen desaturation was related to a smaller hippocampus (B=−0.22 ml, 95% CI=−0.42; −0.01). Although a higher AHI was related to smaller parietal gray (B=−0.05, 95% CI=−0.09; −0.004) and white matter (B=−0.06, 95% CI=−0.12; −0.10) volumes, these associations disappeared when adding oxygen desaturation to the model. We did not find a relation between arousals and gray and white matter brain atrophy and white matter lesion volumes. This suggests that oxygen desaturation mainly explains the association between sleep apnea and brain damage.

Background: Chronic obstructive pulmonary disease (COPD) is frequently associated with exertional oxygen desaturation, which may be evaluated using the 6-minute walking test (6MWT). However, it is a time-consuming test. The 1-minute sit-to-stand test (1STST) is a simpler test, already used to evaluate the functional status. The aim of this study was to compare the 1STST to the 6MWT in the evaluation of exertional desaturation. Methods: This was a cross-sectional study including 30 stable COPD patients who performed the 6MWT and 1STST on the same day. Six-minute walking distance (6MWD), number of 1STST repetitions (1STSTr), and cardiorespiratory parameters were recorded. Results: A significant correlation was found between the 6MWD and the number of 1STSTr (r = 0.54; p = 0.002). The minimum oxygen saturation (SpO2) in both tests showed a good agreement (intraclass correlation coefficient (ICC) 0.81) and correlated strongly (r = 0.84; p < 0.001). Regarding oxygen desaturation, the total agreement between the tests was 73.3% with a fair Cohen’s kappa (κ = 0.38; p = 0.018), and 93.33% of observations were within the limits of agreement for both tests in the Bland–Altman analysis. Conclusion: The 1STST seems to be a capable tool of detecting exercise-induced oxygen desaturation in COPD. Because it is a less time- and resources-consuming test, it may be applied during the outpatient clinic consultation to regularly evaluate the exercise capacity and exertional desaturation in COPD.

A 54-year-old woman was referred for veno-venous extracorporeal oxygenation membrane (VV-ECMO) due to refractory hypoxic respiratory failure caused by COVID-19, despite mechanical ventilation and prolonged prone positioning.

Exercise-induced oxygen desaturation (EID) is prevalent in people with chronic obstructive pulmonary disease (COPD). This article reports a sub-analysis from a randomized controlled trial (RCT) in people with COPD and EID (COPD/EID). The primary aim, in people with COPD/ EID, was to determine the repeatability of the distance and time walked in the incremental shuttle walk test (ISWT) and endurance shuttle walk test (ESWT), respectively. A secondary aim was to determine whether any participant characteristics predicted those who did not demonstrate improvements on a repeat ISWT or ESWT. Participants with nadir oxygen saturation (SpO2) < 90% on the 6-minute walk test were recruited to the RCT. Two ISWTs and two ESWTs were then performed as part of the baseline assessments, and participants were included in this sub-analysis if their nadir SpO2 was <90% during the better of two ISWTs. Repeatability of the tests was analysed using Bland–Altman plots and paired t-tests. Participant characteristics of age, lung function, level of nadir SpO2 and end-test dyspnoea were used to predict those who were not likely to demonstrate improvements on a repeat test using receiver operating curves. Eighty-seven participants (mean age (standard deviation, SD) 70 (7) years; forced expiratory volume in one second (FEV1) 47 (17)% predicted) were included. The mean differences (coefficient of repeatability) for the ISWTs and ESWTs were 9 m (55 m) and 19 seconds (142 seconds) respectively (p < 0.05). No participant characteristic predicted the absence of improvement on the second ISWT (area under the curve (AUC) ranged from 0.49 to 0.58, all p > 0.2) or the second ESWT (AUC ranged from 0.43 to 0.52, all p > 0.3). Although repeating the tests showed only small improvements in distance (ISWT) and time (ESWT) walked in people with COPD/EID, the variability was large making definite conclusions about test repeatability in these individuals difficult. [ABSTRACT FROM AUTHOR]

We investigated the relationship between ambulatory blood pressure (BP) and oxygen desaturation index (ODI), while accounting for pulse rate and age. ODI was assessed by overnight finger pulse oximetry in 2342 participants on the day of ambulatory BP monitoring, and calculated as the number of desaturation episodes per sleeping hour. Both BP and pulse rate increased significantly (P ≤ .006) from normal (< 5 events/h) to mildly (5-14), moderately (15-30), and severely (≥ 30 events/h) elevated ODI. The association for BP was substantially attenuated by accounting for pulse rate (partial r² from .003-.012 to .002-.006). In adjusted analysis, the associations of 24-hour diastolic BP and 24-hour pulse rate with ODI were dependent on age (P ≤ .0001) and only significant in younger subjects (< 60 years, P ≤ .0001). In conclusion, the association between ambulatory BP and ODI was partially mediated by pulse rate, a measure of sympathetic activity, and was more prominent in younger subjects. [ABSTRACT FROM AUTHOR]

The 6-minute walk test (6MWT) is not intended to document oxygen (O2) desaturation during exertion but is often used for this purpose. Because of this, it only has modest reproducibility in determining the need for ambulatory O2 therapy in patients with cardiopulmonary disease. The diagnostic and prognostic value of detecting exertional O2 desaturation is still unknown. The aims of this study were to estimate the prevalence of O2 desaturation during a 6MWT based on pulse oximetry measurements at the beginning and end of a 6MWT in a clinical population of patients with suspected cardiopulmonary disease and to determine whether the pulmonary function test (PFT) can predict exercise-induced desaturation during a 6MWT. This retrospective cohort study reviewed the results of the 6MWT and the PFT (i.e., spirometry, lung volumes, and diffusion capacity) of all patients who were evaluated for suspected cardiopulmonary disease at an academic medical center during a 5-year study period. The patients were categorized into three groups based on the change in O2 saturation by pulse oximetry (SpO2) from start to end of the 6MWT: (1) SpO2 decreased by ≥3%; (2) SpO2 unchanged (−2 ≤ Δ ≤ 0%); and (3) SpO2 increased by ≥1%. Demographic, anthropometric, and lung function measurements were analyzed to determine which factors predicted O2 desaturation during the 6MWT. Of the 319 patients who underwent the 6MWT and the PFT from November 2005 until December 2010 (mean age = 54 ± 0.78 years, 63% women, 58% Whites, body mass index = 29.63 ± 8.10 kg/m2), 113 (35%) had a decreased SpO2, 146 (46%) had no change, and 60 (19%) had an increased SpO2 from the start to end of test. Our bivariate analysis found age, spirometric measures, and diffusion capacity for carbon monoxide (DLCO) had statistically significant inverse associations with the SpO2 change category (p < 0.001). Both a 3% and 4% drop in SpO2 during the 6MWT were statistically significantly associated with an older age, a higher prevalence of obstruction, and reduced forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, DLCO and 6-minute walk distance (6MWD). Multivariable logistic regression analyses revealed that only DLCO was a significant independent predictor of the change in SpO2 and a ≥ 4% O2 desaturation during a 6MWT. Receiver operating curve analysis indicates DLCO cut-off of 45% is 82% sensitive and 40% specific in identifying ≥4% O2 desaturators, with an area under the curve of 0.788 ± 0.039 (p < 0.001). The prevalence of a ≥ 3% oxygen desaturation via pulse oximetry during a 6MWT in our clinical population of patients with suspected cardiopulmonary disease was 35%. Although age, spirometric lung volumes, and DLCO had statistically significant unadjusted inverse associations with the change in SpO2 during a 6MWT, the DLCO is the only significant independent predictor of both the magnitude of the change in SpO2 and the occurrence of O2 desaturation of at least 4%, respectively, during the test. Clinical Implications: A DLCO cut-off of 45% may be useful in identifying patients at risk for exertional hypoxemia during a 6MWT.

Apnea, especially in preterm newborns (AoP) is one of the common problems encountered at neonatal units. Numerous factors are likely to play a role in the etiology of apnea. Recent data sugest a role for genetic predisposition of AoP. It seems, that physiological rather than pathological immaturity of the respiratory, or cardiorespiratory control, play a major part in the pathophysiology of AoP. Immaturity of the brainstem, cerebral cortex, receptors of the lungs and the airways as well as of the chemoreceptors contribute to the development of apnea in preterm newborns. Several neurotransmitters (GABA, adenosin, endorphins) and their maturational changes are including in pathogenesis of apnea, too. The instability of the upper airway in preterm infants, asynchrony of musculature of the upper airway and diaphragm, pathological changes in the upper airway and malformations of the central nervous system might also contribute to the occurrence and severity of AoP. In newborns, apnea occurs more frequently in active sleep than in quiet sleep and the frequency of apnea in active sleep is higher in the warm conditions. Durations of apnea correlate with the body heat loss. Cardiovascular changes during apnea - bradycardia, peripheral vasoconstriction and various changes in peripheral blood flow and pressure occur together with changes in ECG. The standard clinical management of apnea includes non-pharmacological treatment (eliciting arousal reactions and reflex breathing by mechanical skin, or mucosa stimulations), pharmacological treatment (methylxanthines are preferred) and application of continuous positive airway pressure (CPAP) or in severe apnea - mechanical ventilation.

Patients with epilepsy have 20-fold risk of sudden death when compared to the general population. Uncontrolled seizures is the most consistent risk factor, and death often occurs at night or in relation to sleep. We examined seizure-related respiratory disturbances in sleep versus wakefulness, focusing on periictal oxygen saturation. Respiratory measures were examined in 48 recorded seizures (sleep, n = 23, wake, n = 25) from 20 adult patients with epilepsy. Seizures from sleep were associated with lower saturation, as compared to seizures from wakefulness, both during ictal (sleep median = 90.8, wake median = 95.5; p < 0.01) and postictal periods (sleep median = 94.3, wake median = 96.9; p = 0.05). Compared to wake-related seizures, seizures from sleep were also associated with a larger desaturation drop (sleep median = −4.2, wake median = −1.2; p = 0.01). Postictal generalized electroencephalography (EEG) suppression ( PGES) occurred more frequently after seizures from sleep (39%), as compared to wake-related seizures (8%, p = 0.01). Our findings suggest that nocturnal seizures may entail a higher sudden unexpected death in epilepsy (SUDEP) severity burden, as they are associated with more severe and longer hypoxemia events, and more frequently followed by PGES, both factors implicated in sudden death. [ABSTRACT FROM AUTHOR]