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Purpose: We analysed the impact of early systemic insults (hypoxemia and hypotension, SIs) on brain injury biomarker profiles, acute care requirements during intensive care unit (ICU) stay, and 6-month outcomes in patients with traumatic brain injury (TBI). Methods: From patients recruited to the Collaborative European neurotrauma effectiveness research in TBI (CENTER-TBI) study, we documented the prevalence and risk factors for SIs and analysed their effect on the levels of brain injury biomarkers [S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), neurofilament light (NfL), glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), and protein Tau], critical care needs, and 6-month outcomes [Glasgow Outcome Scale Extended (GOSE)]. Results: Among 1695 TBI patients, 24.5% had SIs: 16.1% had hypoxemia, 15.2% had hypotension, and 6.8% had both. Biomarkers differed by SI category, with higher S100B, Tau, UCH-L1, NSE and NfL values in patients with hypotension or both SIs. The ratio of neural to glial injury (quantified as UCH-L1/GFAP and Tau/GFAP ratios) was higher in patients with hypotension than in those with no SIs or hypoxia alone. At 6 months, 380 patients died (22%), and 759 (45%) had GOSE ≤ 4. Patients who experienced at least one SI had higher mortality than those who did not (31.8% vs. 19%, p < 0.001). Conclusion: Though less frequent than previously described, SIs in TBI patients are associated with higher release of neuronal than glial injury biomarkers and with increased requirements for ICU therapies aimed at reducing intracranial hypertension. Hypotension or combined SIs are significantly associated with adverse 6-month outcomes. Current criteria for hypotension may lead to higher biomarker levels and more negative outcomes than those for hypoxemia suggesting a need to revisit pressure targets in the prehospital settings.

Obstructive sleep apnea (OSA) is a sleep disorder caused by periodic airway obstructions and has been associated with numerous health consequences, which are thought to result from tissue hypoxia. However, challenges in the direct measurement of tissue-level oxygenation make it difficult to analyze the hypoxia exposure pattern in patients. Furthermore, current clinical practice relies on the apnea-hypopnea index (AHI) and pulse oximetry to assess OSA severity, both of which have limitations. To overcome this, we developed a clinically deployable mathematical model, which outputs tissue-level oxygenation. The model incorporates spatial pulmonary oxygen uptake, considers dissolved oxygen, and can use time-dependent patient inputs. It was applied to explore a series of breathing patterns that are clinically differentiated. Supporting previous studies, the result of this analysis indicated that the AHI is an unreliable indicator of hypoxia burden. As a proof of principle, polysomnography data from two patients was analyzed with this model. The model showed greater sensitivity to breathing in comparison with pulse oximetry and provided systemic venous oxygenation, which is absent from clinical measurements. In addition, the dissolved oxygen output was used to calculate hypoxia burden scores for each patient and compared to the clinical assessment, highlighting the importance of event length and cumulative impact of obstructions. Furthermore, an intra-patient statistical analysis was used to underscore the significance of closely occurring obstructive events and to highlight the utility of the model for quantitative data processing. Looking ahead, our model can be used with polysomnography data to predict hypoxic burden on the tissues and help guide patient treatment decisions.

Anemia and hypoxemia are common clinical conditions that are difficult to study and may impact pulse oximeter performance. Utilizing an in vitro circulation system, we studied performance of three pulse oximeters during hypoxemia and severe anemia. Three oximeters including one benchtop, one handheld, and one fingertip device were selected to reflect a range of cost and device types. Human blood was diluted to generate four hematocrit levels (40%, 30%, 20%, and 10%). Oxygen and nitrogen were bubbled through the blood to generate a range of oxygen saturations (O2Hb) and the blood was cycled through the in vitro circulation system. Pulse oximeter saturations (SpO2) were paired with simultaneously-measured O2Hb readings from a reference CO-oximeter. Data for each hematocrit level and each device were least-squares fit to a 2nd-order equation with quality of each curve fit evaluated using standard error of the estimate. Bias and average root mean square error were calculated after correcting for the calibration difference between human and in vitro circulation system calibration. The benchtop oximeter maintained good accuracy at all but the most extreme level of anemia. The handheld device was not as accurate as the benchtop, and inaccuracies increased at lower hematocrit levels. The fingertip device was the least accurate of the three oximeters. Pulse oximeter performance is impacted by severe anemia in vitro. The use of in vitro calibration systems may play an important role in augmenting in vivo performance studies evaluating pulse oximeter performance in challenging conditions.

Objectives: For patients admitted with an acute exacerbation of COPD (AECOPD) and a need for supplementary oxygen therapy, to determine if peripheral oxygen saturation < 88% (hypoxemia) or >92% (hyperoxemia), within first 24 hours of admission, is associated with ‘treatment failure’ or fewer days alive and out of hospital within 14 days after admission. Design: A retrospective multicenter observational study, reviewing consecutive data on SpO2, oxygen, and drug administration at three predefined time points, on adverse events in patients admitted with COPD between December 2019 and June 2020. Multivariable logistic regression analysis, Mann Whitney U- and Chi-square-test were used. Setting: Acute hospital setting, across four different hospitals in the capital region of Denmark. Participants: Patients with a confirmed diagnosis of COPD admitted with an acute exacerbation and an oxygen need within the first 24 hours admission. Results: In total 289 COPD patients were included. The median age was 74.8 years [interquartile range (IQR):69.6 to 81.8], 191 were female and 132 patients experienced ‘treatment failure’. A minimum of one episode of hypoxemia (SpO2 < 88%) within first 24 hours was associated with having a low number (≤4) of days alive and out of hospital within 14 days after admission: OR 2.4 (95%CI 1.2 to 4.8), p = 0.02, absolute risk 44% vs. 26% p = 0.01, Chi-square. Comparable results were observed after 30 days of follow-up: OR 2.6 (95% CI 1.0 to7.1), p = 0.05. A minimum of one measurement of hyperoxemia (SpO2 > 92%), within first 24 hours of admission was not associated with low number of days alive and out of hospital within 14 days OR 1.0 (95% CI 0.5 to 2.1) nor at 30 days. Conclusion: For admitted patients with AECOPD, being hypoxemic ever within the first 24 hours after admission is associated with a substantially increased risk of a poor prognosis.

Acute Respiratory Distress Syndrome (ARDS) is one of the most common causes of admission to the intensive care unit that frequently requires mechanical ventilation and in the most severe cases, rescue therapies are implemented to correct refractory hypoxemia and/or hypercapnia (severe breathing problems). Among these, extracorporeal membrane oxygenation (ECMO) (a machine for breathing support) is increasingly used, as it proved to be effective in supporting the function of failing lungs. However, ECMO is a complex technique and the management of patients receiving ECMO support is particularly challenging. The aim of this dissertation was to improve the management of mechanical ventilation and monitoring of lung function during ECMO and to improve the current knowledge of some complications occurring in patients receiving ECMO support. The results may help clinicians to improve patient monitoring and management during ECMO support.

Acute respiratory distress syndrome (ARDS) is a pathology frequently presented in the Intensive Care Unit, having high mortality and long-term sequelae as it is a heterogeneous entity that is difficult to address and lacks a specific treatment; Therefore, historically efforts have been combined in order to have diagnostic criteria that allow its early identification and approach. Half of the cases are characterized by a disease with diffuse alveolar damage (DAD) and the rest by a diverse histological pattern secondary to already characterized diseases that, if diagnosed and treated specifically based on the etiology, show a benefit and improved prognosis. of the patient., El síndrome de distrés respiratorio agudo (SDRA) es una patología frecuentemente presentada en la Unidad de Cuidados Intensivos, teniendo una alta mortalidad y secuelas a largo plazo al ser una entidad heterogénea difícil de abordar y no contarse con un tratamiento específico; por lo que históricamente se han aunado esfuerzos con el fin de tener criterios diagnósticos que permitan su identificación y abordaje temprano. La mitad de los casos se caracterizan por ser una enfermedad con daño alveolar difuso (DAD) y el resto por un patrón histológico diverso secundario a enfermedades ya caracterizadas que de ser diagnósticadas y tratadas específicamente al ser la etiología, muestran un beneficio y mejoría del pronóstico del paciente.

The common pulmonary consequence of SARS-CoV-2 infection is pneumonia, but vascular clot may also contribute to COVID pathogenesis. Imaging and hemodynamic approaches to identifying diffuse pulmonary vascular obstruction (PVO) in COVID (or acute lung injury generally) are problematic particularly when pneumonia is widespread throughout the lung and hemodynamic consequences are buffered by pulmonary vascular recruitment and distention. Although stimulated by COVID-19, we propose a generally applicable bedside gas exchange approach to identifying PVO occurring alone or in combination with pneumonia, addressing both its theoretical and practical aspects. It is based on knowing that poorly (or non) ventilated regions, as occur in pneumonia, affect O2 more than CO2, whereas poorly (or non) perfused regions, as seen in PVO, affect CO2 more than O2. Exhaled O2 and CO2 concentrations at the mouth are measured over several ambient-air breaths, to determine mean alveolar Po2 and Pco2. A single arterial blood sample is taken over several of these breaths for arterial Po2 and Pco2. The resulting alveolar-arterial Po2 and Pco2 differences (AaPo2, aAPco2) are converted to corresponding physiological shunt and deadspace values using the Riley and Cournand 3-compartment model. For example, a 30% shunt (from pneumonia) with no alveolar deadspace produces an AaPO2 of almost 50 torr, but an aAPco2 of only 3 torr. In contrast, a 30% alveolar deadspace (from PVO) without shunt leads to an AaPO2 of only 12 torr, but an aAPco2 of 9 torr. This approach can identify and quantify physiological shunt and deadspace when present singly or in combination.NEW & NOTEWORTHY Identifying pulmonary vascular obstruction in the presence of pneumonia (e.g., in COVID-19) is difficult. We present here conversion of bedside measurements of arterial and alveolar Po2 and Pco2 into values for shunt and deadspace-when both coexist-using Riley and Cournand's 3-compartment gas exchange model. Deadspace values

BACKGROUND: Treating hypoxemia while meeting the soaring demands of oxygen can be a challenge during the COVID-19 pandemic. OBJECTIVE: To determine the efficacy of the surgical facemask and the double-trunk mask on top of the low-flow oxygen nasal cannula on arterial partial pressure of oxygen (PaO2) in hypoxemic COVID-19 patients. DESIGN: Randomized controlled trial. PARTICIPANTS: Hospitalized adults with COVID-19 and hypoxemia treated with the low-flow nasal cannula were enrolled between November 13, 2020, and March 05, 2021. INTERVENTIONS: Patients were randomized in a 1:1:1 ratio to receive either the nasal cannula alone (control) or the nasal cannula covered by the surgical facemask or the double-trunk mask. Arterial blood gases were collected at baseline and 30 min after the use of each system. The oxygen output was adapted afterwards to retrieve the baseline pulse oxygen saturation. The final oxygen output value was recorded after another 30-min period. MAIN MEASURES: The primary outcome was the absolute change in PaO2. Secondary outcomes included changes in oxygen output, arterial partial pressure of carbon dioxide (PaCO2), vital parameters, and breathlessness. KEY RESULTS: Arterial blood samples were successfully collected in 24/27 (8 per group) randomized patients. Compared to the nasal cannula alone, PaO2 increased with the surgical facemask (mean change: 20 mmHg, 95% CI: 0.7-38.8; P = .04) and with the double-trunk mask (mean change: 40 mmHg; 95% CI: 21-59; P < .001). Oxygen output was reduced when adding the surgical facemask (median reduction: 1.5 L/min [95% CI: 0.5-4.5], P < .001) or the double-trunk mask (median reduction: 3.3 L/min [95% CI: 2-5], P < .001). The double-trunk mask was associated with a PaCO2 increase of 2.4 mmHg ([95% CI: 0-4.7], P = .049). Neither mask influenced vital parameters or breathlessness. CONCLUSIONS: The addition of the surgical facemask or the double-trunk mask above the nasal cannula improves arterial oxygenation and red

STUDY OBJECTIVES: Nocturnal symptoms are very common in asthma, which is associated with worse sleep quality. The nocturnal oxygen saturation may be decreased in asthma; however, whether this association is dependent on nocturnal asthma symptoms, lung function, coexisting obstructive sleep apnea (OSA), or other asthma-related comorbidities is unknown. The objective of this study was to examine the effects of asthma, OSA, lung function, airway symptoms, and asthma-related comorbidities on the nocturnal oxygen saturation in a cross-sectional community-based population study. METHODS: In total, 395 women and 392 men underwent overnight polysomnography, performed spirometry, and completed questionnaires on airway symptoms and asthma-related comorbidities. RESULTS: Participants with asthma (n = 88) had a lower nocturnal oxygen saturation than those without asthma (93.8% vs 94.3%, P = .01) also after adjusting for comorbidity, age, body mass index, and smoking status (coefficient -0.38; CI -0.67, -0.10; P < .01). The nocturnal oxygen saturation was lower among participants with wheezing, nocturnal chest tightness, fixed airflow limitation, gastroesophageal reflux, obesity, and OSA than in those without these conditions. The associations between lower oxygen saturation and wheezing, forced expiratory volume in 1 second, gastroesophageal reflux, and apnea-hypopnea index were significant also after adjusting for age, sex, body mass index, and smoking status. Participants with both wheezing and OSA had a significantly lower nocturnal oxygen saturation (92.5 ± 0.5%) than participants with wheezing only (94.3 ± 0.3%) and OSA only (93.6 ± 0.2% %) (P < .01). CONCLUSIONS: Participants with asthma displayed a lower mean oxygen saturation during sleep, which could not be explained only by coexisting OSA or obesity. Also, asthma symptoms and lung function were associated with lower nocturnal oxygen saturation. The lower oxygen saturation seen in asthma is hence multifactorial i

Background: The aim of the study was to investigate whether findings in cardiorespiratory polygraphy had an association with stroke mortality or ischemic event recurrence after ischemic stroke. Methods: We prospectively studied 204 ischemic stroke patients who underwent cardiorespiratory polygraphy within the first 48 h after the symptom onset. We followed all these patients for a median of 6.2 years. We evaluated mortality, time of survival, causes of death and new ischemic events. Results: Of 204 ischemic stroke patients, 43 died and 48 had a new ischemic event during the follow-up. The lowest arterial oxyhemoglobin saturation (min SaO₂) (P = 0.007) was lower, the percentage of time spent below arterial oxyhemoglobin saturation less than 90% (T90) (P = 0.005) was higher, and central apnea index per hour (CAI/h) (P = 0.04) was higher among the deceased. Male gender, older age, diabetes mellitus, elevated modified Rankin scale (mRS) score, lower Glasgow Coma Scale (GCS) score and CAI/h independently predicted higher mortality. Peripheral arterial disease (PAD) and higher National Institutes of Health Stroke Scale (NIHSS) score were independent predictors for a recurrent ischemic event. Among those having respiratory event index (REI) at least 30, older age and lower GCS score independently predicted higher mortality. Only 21 stroke patients initiated continuous positive airway pressure (CPAP) treatment; of those, only one had a new ischemic event. Conclusions: The non-survivors had more severe nocturnal hypoxemia and more central apneas than survivors. Among patients with REI at least 30/h, increased CAI predicted higher mortality, but not independently.

Pulmonary hypertension (PH) is prevalent in obesity hypoventilation syndrome (OHS). However, there is a paucity of data assessing pathogenic factors associated with PH. Our objective is to assess risk factors that may be involved in the pathogenesis of PH in untreated OHS.

BackgroundThe SafeBoosC II, randomised clinical trial, showed that the burden of cerebral hypoxia was reduced with the combination of near infrared spectroscopy and a treatment guideline in extremely preterm infants during the first 72 hours after birth. We have previously reported that a high burden of cerebral hypoxia was associated with cerebral haemorrhage and EEG suppression towards the end of the 72-hour intervention period, regardless of allocation. In this study we describe the associations between the burden of cerebral hypoxia and the 2-year outcome.MethodsCerebral oxygenation was continuously monitored from 3 to 72 hours after birth in 166 extremely preterm infants. At 2 years of age 114 of 133 surviving children participated in the follow-up program: medical examination, Bayley II or III test and the parental Ages and Stages Questionnaire. The infants were classified according to the burden of hypoxia: within the first three quartiles (n = 86, low burden) or within in the 4(th) quartile (n = 28, high burden). All analyses were conducted post hoc.ResultsThere were no statistically significant differences between the quantitative assessments of neurodevelopment in the groups of infants with the low burden of cerebral hypoxia versus the group of infants with the high burden of cerebral hypoxia. The infants in the high hypoxia burden group had a higher-though again not statistically significant-rate of cerebral palsy (OR 2.14 (0.33-13.78)) and severe developmental impairment (OR 4.74 (0.74-30.49).ConclusionsThe burden of cerebral hypoxia was not significantly associated with impaired 2-year neurodevelopmental outcome in this post-hoc analysis of a feasibility trial.

SCOPUS: no.j, info:eu-repo/semantics/published

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in China in December 2019 and became a pandemic in a short period of time. While most infected people might have mild symptoms, older people and people with chronic illnesses may develop acute respiratory distress syndrome (ARDS). Patients with ARDS with worsening hypoxemia require prone positioning to improve the respiratory mechanics and oxygenation. Intubated patients may stay in a prone position up to 12-16 h, increasing the risk of pressure injury (PI). Frequent skin inspections and PI risk assessment in COVID-19 patients will be challenging due to hospital infection control measures aimed to reduce the risk for health professionals. In this perspective article, we summarize the best practice recommendations for prevention of PI in SARS-CoV-2-infected ARDS patients in prone positioning. Prior to positioning patients in prone position, the main recommendations are to (1) conduct a skin assessment, (2) use pressure redistribution devices, (3) select an appropriate mattress or an overlay, (4) ensure that the endotracheal tube securing device is removed and the endotracheal tube is secured with tapes, (5) use a liquid film-forming protective dressing, and (6) lubricate the eyes and tape them closed. Once a patient is in prone position, it is recommended to (1) use the swimmer's position, (2) reposition the patient every 2 h, and (3) keep the skin clean. When the patient is repositioned to supine position, healthcare professionals are advised to (1) assess the pressure points and (2) promote early mobilization.© Copyright © 2021 Team, Team, Jones, Teede and Weller.

Agonists of alpha2-adrenoceptors are increasingly being used for the provision of comfort, sedation and the management of delirium in critically ill patients, with and without sepsis. In this context, increased sympathetic and inflammatory activity are common pathophysiological features linked to multi-organ dysfunction, particularly in patients with sepsis or those undergoing cardiac surgery requiring cardiopulmonary bypass. Experimental and clinical studies support the notion that the alpha2-adrenoceptor agonists, dexmedetomidine and clonidine, mitigate sympathetic and inflammatory overactivity in sepsis and cardiac surgery requiring cardiopulmonary bypass. These effects can protect vital organs, including the cardiovascular system, kidneys, heart and brain. We review the pharmacodynamic mechanisms by which alpha2-adrenoceptor agonists might mitigate multi-organ dysfunction arising from pathophysiological conditions associated with excessive inflammatory and adrenergic stress in experimental studies. We also outline recent clinical trials that have examined the use of dexmedetomidine in critically ill patients with and without sepsis and in patients undergoing cardiac surgery.Copyright © 2021 The British Pharmacological Society

BACKGROUND AND AIM: Whether long-term oxygen therapy (LTOT) improves survival in interstitial lung disease (ILD) is unclear. A recent study reported similar survival in ILD patients with severe hypoxemia on LTOT vs. moderate hypoxemia without LTOT, and proposed that LTOT could be indicated in ILD already at moderate hypoxemia. The aim of this study was to compare survival by severity of hypoxemia in patients with ILD and COPD, respectively, treated with LTOT. METHODS: A population-based, longitudinal study of adults starting LTOT for ILD or COPD 1987-2018. Transplant-free survival was compared between moderate (PaO2 7.4-8.7 kPa) and severe (PaO2<7.4 kPa) hypoxemia using Cox regression, adjusted for age, sex, BMI, smoking status, WHO performance status, year of starting LTOT, diagnosis of heart failure, ischemic heart disease and diabetes mellitus. RESULTS: In total, 17,084 patients were included, with ILD and moderate (n = 470) or severe hypoxemia (n = 2,408), and COPD with moderate (n = 2,087) or severe hypoxemia (n = 12,119). Compared with in COPD, ILD patients on LTOT had lower transplant-free survival after one year (41.9 vs. 67.1%) and two years (20.3 vs. 46.5%). In COPD worse hypoxemia was associated with slightly increased risk of death/lung transplantation, aHR 1.07 (1.00-1.14), a difference not shown in ILD, aHR 0.91 (0.80-1.03). CONCLUSION: Transplant-free survival did not differ in ILD patients between moderate and severe hypoxia despite LTOT.

Oxygen gas flowmeters (OGF) are used to regulate the oxygen flow in acute and chronic care. In hospitals, Thorpe tubes (TT) are the classical systems most used for delivering oxygen. In recent years, the oxygen flow restrictor (OFR) has appeared. These devices use a series of calibrated openings in a disk that can be adjusted to deliver different flow rates. These devices have a reputation for delivering more accurate oxygen flow rates compared to classical OGFs. However, to our knowledge, few study has examined this supposition. This study aimed to compare and evaluate the accuracy and precision of the ready-to-use TTs and OFRs. OGFs were selected from hospitals in Belgium and France. Before performing the flow measurements, the inlet pressure was checked. The accuracy of the OGF was analyzed with a calibrated thermal mass flowmeter (RED Y COMPACT™ GCM-0 to 20 L/min-VÖGTLIN Instruments). Different flows (2, 4, 6, 9 or 12 L/min) were evaluated. Linear regression analysis, bias (with confidence interval) and lower and upper limit of the agreement were calculated for TTs and OFRs. All measurements are expressed in absolute values. Four-hundred-seventy-six TTs and 96 OFRs were analyzed. The intra-class correlation coefficient calculated for the calibrated thermal mass flowmeter was > 0.99 and reflected the excellent reliability of our measurements. For TTs, the bias value was - 0.24 L/min (± 0.88), and the limits of agreement were - 1.97 to 1.48 L/min. For OFRs, the bias value was - 0.30 L/min (± 0.54), and the limits of agreement were - 1.36 to 0.77 L/min. As the flow increased, the accuracy of all analyzed OGFs decreased. With the increasing flow, some data fell outside the limits of agreement, and the trend increased with the elevated oxygen flow. TTs were less accurate compared to OFRs due to the increased flow variability. However, for TTs and OFRs, as the required flow is elevated, the dispersion of values increases on both sides of the actual flow.

Transposition of the great arteries (TGA) is one of the most common cyanotic congenital heart diseases requiring neonatal surgical intervention. Parallel circulations that result in impaired cerebral oxygen delivery already in utero may lead to brain damage and long-term neurodevelopmental delay. Balloon atrial septostomy (BAS) is often employed to mix deoxygenated and oxygenated blood at the atrial level. However, BAS causes a sudden increase in arterial blood oxygenation and oxidative stress. We studied changes in oxygen saturation as well as metabolic profiles of plasma samples from nine newborn infants suffering from TGA before and until 48 h after undergoing BAS. The plasma metabolome clearly changed over time and alterations of four metabolic pathways, including the pentose phosphate pathway, were linked to changes in the cerebral tissue oxygen extraction. In contrast, no changes in levels of lipid peroxidation biomarkers over time were observed. These observations suggest that metabolic adaptations buffer the free radical burst triggered by re-oxygenation, thereby avoiding structural damage at the macromolecular level. This study enhances our understanding of the complex response of infants with TGA to changes in oxygenation induced by BAS.

Transfusion Acute Lung Injury (TRALI) is a serious and life-threatening syndrome. The FDA has reported that TRALI is the leading cause of transfusion-related deaths for many years, with 34% of TRALI fatalities (64/186 reported transfusion-related deaths between 2012 and 2016). The association between human neutrophil antigen (HNA) or human leukocyte antigen (HLA) found in antibodies in donor blood is associate to TRALI and TACO syndromes. With suggestive symptoms within 6 hours after a blood transfusion and infiltrates on a chest radiograph indicating the presence of pulmonary edema. This syndrome has improved a lot over the last two decades, measures to mitigate the risk of TRALI have been implemented around the world., La lesión pulmonar aguda producida por transfusión (TRALI) es un síndrome grave y potencialmente mortal. La FDA ha informado que TRALI es la principal causa muertes relacionadas con transfusiones durante muchos años, con el 34% de las víctimas mortales de TRALI (64/186 reportaron muertes relacionadas con transfusiones entre 2012 y 2016). La asociación entre el antígeno humano de neutrófilos (HNA) o antígeno leucocitario humano (HLA) que se encuentran en los anticuerpos en sangre de donantes asocia los síndromes de TRALI y TACO. Con síntomas sugestivos dentro de las 6 horas posteriores a una transfusión sanguínea e infiltrados en una radiografía de tórax indicando de la presencia de edema pulmonar. Este síndrome ha mejorado mucho durante las dos últimas décadas, se han implementado medidas para mitigar el riesgo de TRALI en todo el mundo.

Introduction: Patients admitted with COVID-19 often have severe hypoxemic respiratory insufficiency and it can be difficult to maintain adequate oxygenation with oxygen supplementation alone. There is a physiological rationale for the use of Continuous Positive Airway Pressure (CPAP), and CPAP could keep some patients off mechanical ventilation. We aimed to examine the physiological response to CPAP and the outcome of this treatment. Methods: Data from all patients admitted with COVID-19 and treated with CPAP, from March to July 2020 were collected retrospectively. CPAP was initiated on a medical ward when oxygen supplementation exceeded 10 liters/min to maintain oxygen saturation (SpO2) ≥92%. CPAP was administered with full face masks on a continuous basis until stable improvement in oxygenation or until intubation or death. Results: CPAP was initiated in 53 patients (35 men, 18 women) with a median (IQR) age of 68 (57–78) years. Nine patients were not able to tolerate the CPAP treatment. Median duration for the 44 patients receiving CPAP was 3 (2–6) days. The PaO2/FiO2 ratio was severely reduced to an average of 101 mmHg at initiation of treatment. A positive response of CPAP was seen on respiratory rate (p = 0.002) and on oxygenation (p < 0.001). Of the 44 patients receiving CPAP, 12 (27%) avoided intubation,13 (29%) were intubated, and 19 (43%) died. Of the patients with a ceiling of treatment in the ward (26 of 53) only 2 survived. Older age and high initial oxygen demand predicted treatment failure. Discussion: CPAP seems to have positive effect on oxygenation and respiratory rate in most patients with severe respiratory failure caused by COVID-19. Treatment with CPAP to severely hypoxemic patients in a medical ward is possible, but the prognosis for especially elderly patients with high oxygen requirement and with a ceiling of treatment in the ward is poor.

Platypnea-orthodeoxia syndrome (POS) is a rare condition characterized by dyspnoea (platypnea) and arterial desaturation in the upright position resolved in the supine position (orthodeoxia). Intracardiac shunt, pulmonary ventilation-perfusion mismatch and others intrapulmonary abnormalities are involved., SCOPUS: ar.j, info:eu-repo/semantics/published

Cor pulmonale can be defined by right heart failure secondary to diseases affecting the structure and function of the lungs. It used to be a postmortem pathological definition but now relies on imaging combined or not with a right heart catheterization. The most common cause of cor pulmonale is chronic obstructive pulmonary disease. The sine qua non condition of cor pulmonale is an excessive afterload on an increase in pulmonary artery pressures. The right ventricle initially adapts increased loading by increased contractility and hypertrophy without increased dimensions. There may even be decreased dimensions due to dynamic hyper-inflation impeding systemic venous return, then creating a condition recently identified as cor pulmonale parvus. With evolution of the disease, chronic inflammation, hypoxemia and hormonal disturbances, salt and water retention concur with exhaustion of systolic function adaptation to only mild pulmonary hypertension to produce the clinical picture of systemic congestion with hepatomegaly, turgescent jugular veins and eventual ascites. Cor pulmonale is associated with a limitation to exercise capacity and a poor prognosis. Treatment of cor pulmonale includes correction of hypoxemia with supplemental oxygen, relief of hypercapnic acidosis by ventilatory support and diuretics to control fluid retention. Vasodilators including those interfering with the endothelin, nitric oxide-soluble guanylate cyclase and prostacyclin pathways effective in the treatment of pulmonary arterial hypertension have repeatedly failed to show benefit. The ultimate treatment for refractory cor pulmonale is lung transplantation as right heart structure and function return to normal or near-normal after correction of the causal lung condition., SCOPUS: ch.b, info:eu-repo/semantics/published

Anesthesiologists have routinely administered supplementary oxygen to prevent maternal hypoxemia and improve fetal oxygenation during cesarean delivery under spinal anesthesia. Some reports have indicated an increase in fetal free radicals due to prophylactic oxygen administration. The risk factors for hypoxemia during cesarean delivery still remain unclear. Therefore, in this retrospective study, we investigated the incidence of intraoperative hypoxemia and its associated risk factors in 155 patients receiving spinal anesthesia for cesarean delivery. Our study demonstrated that the incidence of intraoperative hypoxemia was high（ 32.3%） in patients receiving spinal anesthesia for cesarean in the absence of supplemental oxygen. It also indicated that spinal block levels higher than T3 or more were associated with intraoperative hypoxemia. Therefore, it is important to carefully observe parturients intraoperatively and prepare to promptly administer oxygen and other treatments if necessary.

BackgroundSleep Disordered Breathing (SDB) is associated with a wide range of pathophysiological changes due, in part, to hypoxemia during sleep. We sought to identify gene transcription associations with measures of SDB and hypoxemia during sleep, and study their response to treatment.MethodsIn two discovery cohorts, Framingham Offspring Study (FOS; N = 571) and the Multi-Ethnic Study of Atherosclerosis (MESA; N = 580), we studied gene expression in peripheral blood mononuclear cells in association with three measures of SDB: Apnea Hypopnea Index (AHI); average oxyhemoglobin saturation (avgO2) during sleep; and minimum oxyhemoglobin saturation (minO2) during sleep. Associated genes were used for analysis of gene expression in the blood of 15 participants with moderate or severe obstructive sleep apnea (OSA) from the Heart Biomarkers In Apnea Treatment (HeartBEAT) trial. These genes were studied pre- and post-treatment (three months) with continuous positive airway pressure (CPAP). We also performed Gene Set Enrichment Analysis (GSEA) on all traits and cohort analyses.FindingsTwenty-two genes were associated with SDB traits in both MESA and FOS. Of these, lower expression of CD1D and RAB20 was associated with lower avgO2 in MESA and FOS. CPAP treatment increased the expression of these genes in HeartBEAT participants. Immunity and inflammation pathways were up-regulated in subjects with lower avgO2; i.e., in those with a more severe SDB phenotype (MESA), whereas immuno-inflammatory processes were down-regulated following CPAP treatment (HeartBEAT).InterpretationLow oxygen saturation during sleep is associated with alterations in gene expression and transcriptional programs that are partially reversed by CPAP treatment.

Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073

Introduction: Patients with coronavirus disease (COVID-19) and pneumonitis often have hypoxemic respiratory failure and a need of supplementary oxygen. Guidelines recommend controlled oxygen, for most patients with a recommended interval of SpO2 between 92 and 96%. We aimed to determine if closed-loop control of oxygen was feasible in patients with COVID-19 and could maintain SpO2 in the specified interval. Methods: Patients were prospectively enrolled in an observational study on a medical ward dedicated to patients with COVID-19. Closed-loop controlled oxygen was delivered by O2matic® which can deliver 0–15 liters/min and adjusts flow every second based on 15 seconds averaging of SpO2 measured by pulse oximetry. Lung function parameters were measured at admission. Results: Fifteen patients (six women, nine men) participated in the study. Average age was 72 years. Lung function was severely impaired with FEV1, FVC and PEF reduced to approximately 50%. The average stay on the ward was 3.2 days and O2matic was used on average for 66 hours, providing 987 hours of observation. O2matic maintained SpO2 in the desired interval for 82.9% of the time. Time with SpO2 > 2% below interval was 5.1% and time with SpO2 > 2% above interval was 0.6%. Conclusion: Closed-loop control of oxygen to patients with COVID-19 is feasible and can maintain SpO2 in the specified interval in the majority of time. Closed-loop automated control could be of particular benefit for patients in isolation with decreased visibility, surveillance and monitoring. Further studies must examine the clinical benefits.

BACKGROUND: Traditional methods for the quantification of OSA severity may not encapsulate potential relationships between hypoxemia in OSA and cardiovascular risk.RESEARCH QUESTION: Do novel nocturnal oxygen saturation (Spo(2)) metrics have prognostic value in patients with OSA and high cardiovascular event risk?STUDY DESIGN AND METHODS: We conducted post hoc analyses of the Sleep Apnea Cardiovascular Endpoints (SAVE) trial. In 2687 individuals, Cox proportional hazards models that were stratified for treatment allocation were used to determine the associations between clinical characteristics, pulse oximetry-derived metrics that were designed to quantify sustained and episodic features of hypoxemia, and cardiovascular outcomes. Metrics included oxygen desaturation index, timeRESULTS: Neither apnea-hypopnea index, oxygen desaturation index, nor any of the novel Spo(2) metrics were associated with the primary SAVE composite cardiovascular outcome. Mean and baseline Spo(2) were associated with heart failure (hazard ratio [HR], 0.81; 95% CI, 0.69-0.95; P = .009; and HR, 0.78; 95% CI, 0.67-0.90; P = .001, respectively) and myocardial infarction (HR, 0.86; 95% CI, 0.77-0.95; P = .003; and HR, 0.81; 95% CI, 0.73-0.90; P <.001, respectively). Desaturation duration and desaturation/resaturation time ratio, with established risk factors, predicted future heart failure (area under the curve, 0.86; 95% CI, 0.79-0.93).INTERPRETATION: Apnea-hypopnea index and oxygen desaturation index were not associated with cardiovascular outcomes. In contrast, the pattern of oxygen desaturation was associated with heart failure and myocardial infarction. However, concomitant risk factors remained the predominant determinants for secondary cardiovascular events and thus deserve the most intensive management.

Objectives: Extracorporeal respiratory support, including low blood flow systems providing mainly extracorporeal CO2 removal, are increasingly applied in clinical practice. Gas exchange physiology during extracorporeal respiratory support is complex and differs between full extracorporeal membrane oxygenation and extracorporeal CO2 removal. Aim of the present article is to review pathophysiological aspects which are relevant for the understanding of hypoxemia development during extracorporeal CO2 removal. We will describe the mathematical and physiologic background underlying changes in respiratory quotient and alveolar oxygen tension during venovenous extracorporeal gas exchange and highlight the clinical implications. Design: Theoretical analysis of venovenous extracorporeal gas exchange. Setting: Italian university research hospital. Patients: None. Interventions: None. Measurements and main results: While the effect of extracorporeal CO2 removal on the respiratory quotient of the native lung has long been known, the role of extracorporeal oxygenation in dictating changes in the respiratory quotient has been less addressed. Indeed, both extracorporeal CO2 removal and extracorporeal oxygen delivery affect the respiratory quotient of the native lung and thus influence the alveolar PO2. Indeed, for the same amount of extracorporeal CO2 extraction, it is possible to reduce the FIO2, reduce the risk of absorption atelectasis, and maintain the same alveolar PO2, by increasing the extracorporeal oxygen delivery. Conclusions: Worsening of hypoxemia is frequent during low-flow extracorporeal CO2 removal combined with ultraprotective mechanical ventilation. In this context, increasing extracorporeal oxygen delivery, increases the respiratory quotient of the native lung and could reduce both the occurrence of alveolar hypoxia and absorption atelectasis, thus optimizing the residual lung function.

Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073

Introduction: To describe a case of nitrofurantoin associated organising pneumonia. Background(s): Nitrofurantoin is an antibacterial agent indicated for treatment of uncomplicated urinary tract infection (UTI) or for prophylaxis in those patients with recurrent UTIs. It is rarely used as a first line agent owing to its potential for adverse reactions such as pulmonary toxicity.1 Organising pneumonia is a pathological syndrome associated with dyspnoea, non-productive cough, bilateral crackles on chest examination and hypoxaemia at rest.2 We report a case of nitrofurantoin associated organising pneumonia responsive to drug withdrawal and corticosteroid initiation, this is a rare occurrence, with only a few reported cases worldwide. Interventions, Case Progress and Outcomes: A 73-year-old female ex-smoker with a history of multiple allergies, Graves' disease, and recurrent UTIs who was treated with long-term nitrofurantoin presented with an 8- week history of worsening dyspnoea on exertion, pleuritic chest pain when coughing, nausea, decreasing appetite, weight loss and increasing lethargy. Computed Tomography (CT) of the chest revealed widespread bilateral airspace and peribronchovascular ground glass opacities indicative of organising pneumonia. Following diagnosis of organising pneumonia, nitrofurantoin was ceased and high dose prednisolone commenced. After rapid clinical response to treatment, the patient was discharged long-term on high dose prednisolone. On routine 4-week follow up, the patient's symptoms had improved significantly. A repeat CT chest demonstrated dramatic reduction in ground glass changes. Conclusion(s): Nitrofurantoin associated organising pneumonia is a rarely reported adverse reaction and is often associated with poor outcomes. 3 This case report highlights that nitrofurantoin associated organising pneumonia can improve dramatically with prompt withdrawal of the causative agent and commencement of corticosteroids. It also reinforces the impor

Whole body ultrasound can be used to improve the speed and accuracy of evaluation of an increasing number of organ systems in the critically ill. Cardiac and abdominal ultrasound can be used to identify the mechanisms and etiology of hemodynamic instability. In hypoxemia or hypercarbia, lung ultrasound can rapidly identify the etiology of the condition with an accuracy that is equivalent to that of computed tomography. For encephalopathy, ocular ultrasound and transcranial Doppler can identify elevated intracranial pressure and midline shift. Renal and bladder ultrasound can identify the mechanisms and etiology of renal failure. Ultrasound can also improve the accuracy and safety of percutaneous procedures and should be currently used routinely for central vein catheterization and percutaneous tracheostomy.Copyright © The Korean Society of Anesthesiologists, 2019.

Conventional therapies for oxygen supply used in the veterinary clinic may be inefficient when offering a satisfactory recovery to post-surgical patients under chest surgical procedures with hypoxemic respiratory failure, de- manding strategies to improve oxygenation indicators. The present work describes the use of high-flow nasal cannulas in two patients submitted to chest surgeries and under general anesthesia. Patient #1 was submitted to a subphrenic pericardiectomy by thoracoscopy, and patient #2 was submitted to a percutaneous rib fracture reduction by a chest tube. Both patients were recovered with a high-flow oxygen therapy in the post-surgical phase at flow rates of 600 and 1,071 mL/kg/minute, respectively. The oxygen was delivered using a commercial device of active humidification, non-condensable suction with heating system and bilateral nasal cannula, offering an air temperature of 37 ºC, humidity of 98% and inspired fraction of oxygen of 50%. A percutaneous gasometry was performed (dorsal metatarsal artery) after 15 minutes of extubating of the patient, and a second arterial sample was collected 60 minutes after the installation of the high-flow device. An increase in the partial pressure of oxygen (PaO2) was observed without an increase in the partial pressure of carbon dioxide (PaCO2). Additionally, both patients reported satisfactory tolerance to the device. High-flow nasal cannulas should be considered within non-invasive ventilatory support strategies during post-extubating in patients submitted to chest surgeries., Resumo As terapias convencionais para oxigênio usado na clínica veterinária podem ser ineficientes quando oferecendo uma recuperação satisfatória dos pacientes pós qirúrgicos sob procedimentos peito insuficiência respiratória hipoxêmica exigindo estratégias para melhorar os indicadores de oxigenação. O presente trabalho des- creve o uso de cânulas nasais de alto fluxo em dois pacientes submetidos a cirur- gias torácicas sob anestesia geral. Paciente #1 foi submetida a pericardiectomia subfrênica por toracoscopia e paciente #2 foi submetida a uma redução percutânea da fratura de costela com tubo torácico. Ambos os pacientes foram recuperados no pós-operatório com oxigeno terapia de alta vazão nas vazões de 600 e 1.071 mL/kg/ minuto, respectivamente. O oxigênio foi entregue através de um dispositivo comercial de umidificação ativa, tubuladura não condensável com sistema de aquecimento e cânula nasal bilateral, oferecendo temperatura do ar de 37 ºC, umidade de 98% e fração inspirada de oxigênio de 50%. A análise gasométrica percutânea (artéria metatarsal dorsal) foi realizada 15 minutos após a extubação do paciente e uma segunda amostra arterial foi coletada 60 minutos após a instalação do dispositivo de alto fluxo. Um aumento na pressão parcial de oxigênio (PaO2) foi observado sem alterações na pressão parcial de dióxido de carbono (PaCO2). Além disso, tolerancia satisfatória ao dispositivo foi relatada por ambos os pacientes. Cânulas de alto fluxo devem ser consideradas dentro das estratégias de suporte ventilatório não invasivo durante a pós-extubação em pacientes submetidos a cirurgias torácicas., Resumen Las terapias convencionales para el aporte de oxígeno usadas en la clínica veterinaria pueden ser ineficientes al momento de ofrecer una recupe- ración satisfactoria de los pacientes posquirúrgicos bajo procedimientos a tórax con falla respiratoria hipoxémica, requiriendo estrategias que mejoren los indicadores de oxigenación. El presente trabajo describe el uso de cánulas nasales de alto flujo en dos pacientes sometidos a cirugías de tórax bajo anestesia general. El paciente #1 fue sometido a pericardiectomía subfrénica por toracoscopía y el paciente #2 fue sometido a una reducción percutánea de fractura de costillas con tubo a tórax. Ambos pacientes fueron recuperados en el posquirúrgico con oxigenoterapia de alto flujo a caudales de 600 y 1.071 mL/kg/minuto, respectivamente. El oxígeno fue en- tregado a través de un dispositivo comercial de humidificación activa, tubuladura no condensable con sistema de calefacción y cánula nasal bilateral, ofreciendo una temperatura del aire de 37 ºC, humedad del 98% y fracción inspirada de oxígeno de 50%. Se realizó gasometría percutánea (arteria dorsal metatarsiana) tras 15 minutos de ser extubado el paciente y una segunda muestra arterial fue colectada 60 minutos luego de la instalación del dispositivo de alto flujo. Se observó un aumento de la presión parcial de oxígeno (PaO2) sin cambios en la presión parcial de dióxido de car- bono (PaCO2). Adicionalmente, se reportó tolerancia satisfactoria al dispositivo por parte de ambos pacientes. Las cánulas de alto flujo deben ser consideradas dentro de las estrategias de soporte ventilatorio no invasivo durante la posextubación en pacientes sometidos a cirugías de tórax.

The subpleural arteriovenous shunts that are hallmarks of hepatopulmonary syndrome may cause stroke.

Study objectivesControversy exists as to whether elevated loop gain is a cause or consequence of obstructive sleep apnea (OSA). Upper airway surgery is commonly performed in Asian patients with OSA who have failed positive airway pressure therapy and who are thought to have anatomical predisposition to OSA. We hypothesized that high loop gain would decrease following surgical treatment of OSA due to reduced sleep apnea severity.MethodsPolysomnography was performed preoperatively and postoperatively to assess OSA severity in 30 Chinese participants who underwent upper airway surgery. Loop gain was calculated using a validated clinically-applicable method by fitting a feedback control model to airflow.ResultsPatients were followed up for a median (interquartile range) of 130 (62, 224) days after surgery. Apnea-hypopnea index (AHI) changed from 60.8 (33.7, 71.7) to 18.4 (9.9, 42.5) events/h (P < .001). Preoperative and postoperative loop gain was 0.70 (0.58, 0.80) and 0.53 (0.46, 0.63) respectively (P < .001). There was a positive association between the decrease in loop gain and the improvement of AHI (P = .025).ConclusionsHigh loop gain was reduced by surgical treatment of OSA in our cohort. These data suggest that elevated loop gain may be acquired in OSA and may provide mechanistic insight into improvement in OSA with upper airway surgery.Clinical trial registrationRegistry: ClinicalTrials.gov, Title: The Impact of Sleep Apnea Treatment on Physiology Traits in Chinese Patients With Obstructive Sleep Apnea, Identifier: NCT02696629, URL: https://clinicaltrials.gov/show/NCT02696629.

Objective: To examine the effect of hypoxemia on fetal heart rate (FHR) variability, using an instrumented pregnant sheep model. Methods: In this prospective study, 19 pregnant sheep were instrumented under general anesthesia, at a mean gestational age of 127 days. After a 5‐day recovery period, hypoxemia was induced by attaching the mother to a rebreathing circuit. Hypoxemia was sustained for 120 min, following which it was reversed until maternal and fetal partial pressure of oxygen (pO₂) returned to baseline. FHR recordings at baseline, after 30 and 120 min of hypoxemia and at recovery were analyzed to calculate short‐term variation (STV) in 16 epochs of 3.75 s, every minute. Phase‐rectified signal averaging (window length (L) = 10, time (T) = 2 and scale (S) = 2) was used to calculate FHR acceleration (AC) and deceleration (DC) capacities. Results: At baseline, mean ± SD fetal pO₂ was 2.90 ± 0.38 kPa. Acute hypoxemia was associated with a significant reduction in mean pO₂ at 30 (1.62 ± 0.37 kPa) and 120 (1.51 ± 0.16 kPa) min. Mean ± SD fetal pO₂ at recovery was 2.86 ± 0.32 kPa. At baseline, median STV, AC and DC were 1.307 (interquartile range (IQR), 0.515–2.508) ms, 1.295 (IQR, 0.990–2.685) beats per minute (bpm) and 1.197 (IQR, 0.850–1.836) bpm, respectively. At 30 min of hypoxemia, the values were 1.323 (IQR, 0.753–2.744) ms, 1.696 (IQR, 1.310–3.013) bpm and 1.584 (IQR, 1.217–4.132) bpm, respectively. At 120 min of hypoxemia, they were 1.760 (IQR, 0.928–4.656) ms, 3.098 (IQR, 1.530–5.163) bpm and 3.054 (IQR, 1.508–4.522) bpm, respectively. At recovery, they changed to 0.962 (IQR, 0.703–1.154) ms, 1.228 (IQR, 1.071–2.234) bpm and 1.086 (IQR, 0.873–1.568) bpm, respectively. Hypoxemia for 30 and 120 min was associated with a significant increase in DC compared to baseline (P = 0.014 and 0.017, respectively). The changes in STV and AC were not significant. Conclusion: Acute hypoxemia is associated with a significant increase in the DC of FHR in a fetal s

Rationale: Despite oxygen's classification as an essential medication by the World Health Organization, it is inconsistently available in many resource-constrained settings. Hypoxemia is associated with increased mortality, and mounting evidence suggests that hyperoxia may also be associated with adverse outcomes. Objectives: To determine if overuse of oxygen for some patients in a Rwandan tertiary care hospital emergency department might coexist with oxygen shortages and underuse of oxygen for other patients, and whether an educational intervention coupled with provision of pulse oximeters could improve the distribution of limited oxygen resources. Methods: We screened all patients in the adult emergency department (ED) of the University Teaching Hospital of Kigali for hypoxemia and receipt of oxygen therapy for 5 weeks. After completing baseline data collection, we provided pulse oximeters and conducted a didactic training with pre- and posttests on oxygen titration, with a chosen target oxygen saturation (SpO2) of 90% to 95%. Four and 12 weeks after the intervention, we evaluated all patients in the ED again for SpO2and receipt of oxygen therapy for 4 weeks each period.We also recorded ED oxygen use and availability of reserve oxygen for the hospital during the three study periods. Results: During all data collection periods, 214 of 1,765 (12.1%) unique patients screened were hypoxemic. The proportion of patient-days with appropriately titrated oxygen therapy (SpO2, 90-95%) increased from 18.7% at baseline to 38.5% and 42.0% at 4 and 12 weeks postintervention (P<0.001). On a multiple-choice examination testing knowledge of appropriate oxygen titration, clinicians' scores improved from average 60% (interquartile range [IQR], 40-80%) correct to 80% (IQR, 60-80%) correct immediately after the educational intervention (P<0.001). Oxygen use in the ED decreased from amedian of 32.0 (IQR, 28.0-35.0) tanks per day to 25.5 (IQR, 24.0-29.0) and 16.0 (IQR, 12.5-21.0) tanks, SCOPUS: ar.j, DecretOANoAutActif, info:eu-repo/semantics/published

Purpose: The aim of the current study was to further investigate the concept of previously reported high occurrence of comorbidities in obstructive sleep patients (OSA) with insomnia-like symptoms. We hypothesized that this finding at least partly is mediated by nocturnal hypoxia. Moreover, we speculated that the spectrum of the clinical OSA phenotypes differs between European geographical regions. Methods: Cohort of the European Sleep Apnea Database (n = 17,325; 29.9% females) was divided into five subcohorts according to geographical region (North, East, South, West, Central) and further into four clinical presentation phenotypes based on daytime symptoms (EDS) and characteristics suggestive of insomnia. Results: The insomnia phenotype (alone or together with EDS) dominated in all European regions. Isolated insomnia, however, was less common in the West. Insomnia phenotype was associated with the highest proportion of cardiovascular comorbidity (51.7% in the insomnia vs. 43.9% in the EDS type). Measures of nocturnal hypoxemia were independently associated with cardiovascular comorbidity in phenotypes with insomnia-like symptoms. The burden of comorbidities was high across all geographical regions and clinical phenotypes. Regional differences were clinically relevant for age (48 vs. 54 years), BMI (29 vs. 34 kg/m2), and ODI (15 vs. 32/h). Conclusion: High prevalence of particularly cardiovascular comorbidity among patients with insomnia-like symptoms was linked to nocturnal hypoxemia. Considerable differences in clinical presentation were found among OSA patients across Europe. Our data underline that physicians should ask their patients with suspected OSA also for insomnia symptoms. It remains to be explored if a reduction of nocturnal hypoxemia predicts the improvement of insomnia symptoms.

BackgroundData on high-flow nasal oxygen after thoracic surgery are limited and confined to the comparison with low-flow oxygen. Different from low-flow oxygen, Venturi masks provide higher gas flow at a predetermined fraction of inspired oxygen (FiO(2)). We conducted a randomized trial to determine whether preemptive high-flow nasal oxygen reduces the incidence of postoperative hypoxemia after lung resection, as compared to Venturi mask oxygen therapy.MethodsIn this single-center, randomized trial conducted in a teaching hospital in Italy, consecutive adult patients undergoing thoracotomic lung resection, who were not on long-term oxygen therapy, were randomly assigned to receive high-flow nasal or Venturi mask oxygen after extubation continuously for two postoperative days. The primary outcome was the incidence of postoperative hypoxemia (i.e., ratio of the partial pressure of arterial oxygen to FiO(2) (PaO2/FiO(2)) lower than 300mmHg) within four postoperative days.ResultsBetween September 2015 and April 2018, 96 patients were enrolled; 95 patients were analyzed (47 in high-flow group and 48 in Venturi mask group). In both groups, 38 patients (81% in the high-flow group and 79% in the Venturi mask group) developed postoperative hypoxemia, with an unadjusted odds ratio (OR) for the high-flow group of 1.11 [95% confidence interval (CI) 0.41-3] (p=0.84). No inter-group differences were found in the degree of dyspnea nor in the proportion of patients needing oxygen therapy after treatment discontinuation (OR 1.34 [95% CI 0.60-3]), experiencing pulmonary complications (OR 1.29 [95% CI 0.51-3.25]) or requiring ventilatory support (OR 0.67 [95% CI 0.11-4.18]). Post hoc analyses revealed that PaO2/FiO(2) during the study was not different between groups (p=0.92), but patients receiving high-flow nasal oxygen had lower arterial pressure of carbon dioxide, with a mean inter-group difference of 2mmHg [95% CI 0.5-3.4] (p=0.009), and were burdened by a lower risk of postopera

Introduction: Hypoxemia is a critical component of several respiratory diseases and is known to be involved in the processes underlying co-morbidities associated to such disorders, notably at the cardiovascular level. Circulating level of Adiponectin (Ad), known as a metabolic regulator and cardio-protective hormone was previously suggested to be reduced by hypoxia but consequences of such variation are unclear. The evaluation of the specific effect of hypoxemia on Ad forms and receptors could improve the understanding of the involvement of Ad axis in hypoxemia-related diseases. Methods: Ad-pathway components were investigated in a murine model of sustained intermittent hypoxemia (FiO2 10%, 8 h/day, 35 days). Results: Sustained intermittent hypoxemia (SIH) induced a redistribution of Ad multimers in favor of HMW forms, without change in total plasmatic level. Mice submitted to hypoxia also exhibited tissue-specific modification of adiporeceptor (AdipoR) protein level without mRNA expression change. A decreased AdipoR2 abundance was observed in skeletal muscle and heart whereas AdipoR1 level was only reduced in muscle. No change was observed in liver regarding AdipoR. Lipid profile was unchanged but glucose tolerance increased in hypoxemic mice. Conclusion: Sustained intermittent hypoxemia, per se, modify Ad oligomerization state as well as AdipoR protein abundance in a tissue-specific way. That suggests alteration in Ad-dependant pathways in pathological conditions associated to SIH. Investigation of Ad-pathway components could therefore constitute useful complementary criteria for the clustering of patients with hypoxemia-related diseases and management of co-morbidities, as well as to develop new therapeutic strategies., SCOPUS: ar.j, info:eu-repo/semantics/published

Patent foramen ovale (PFO), an embryonic remnant of the fetal circulation, is present in 20-25% of adults. Although recent observational studies and clinical trials have established the link between PFO-mediated right-to-left shunting with cryptogenic stroke and migraine with aura, the role of a PFO in exacerbating hypoxemic medical conditions (ie, sleep apnea, chronic obstructive pulmonary disease, pulmonary hypertension, platypnea-orthodeoxia, pulmonary arteriovenous malformation, high-altitude pulmonary edema, and exercise desaturation) remains less understood. PFO-mediated hypoxemia occurs when deoxygenated venous blood from the right atrium enters and mixes with oxygenated arterial blood in the left atrium. Patients with an intracardiac right-to-left shunt may have profound hypoxemia out of proportion to underlying primary lung disease, even in the presence of normal right-sided pressures. The presence of right-to-left cardiac shunting can exacerbate the degree of hypoxemia in patients with underlying pulmonary disorders. In a subset of these patients, percutaneous PFO closure may result in marked improvement in dyspnea and hypoxemia. This review discusses the association between PFO-mediated right-to-left shunting with medical conditions associated with hypoxemia and explores the role of percutaneous PFO closure in alleviating the hypoxemia.

Poor musculoskeletal state is commonly observed in numerous clinical populations such as chronic obstructive pulmonary disease (COPD) and heart failure patients. It, however, remains unresolved whether systemic hypoxemia, typically associated with such clinical conditions, directly contributes to muscle deterioration. We aimed to experimentally elucidate the effects of systemic environmental hypoxia upon inactivity-related muscle wasting. For this purpose, fourteen healthy, male participants underwent three 21-day long interventions in a randomized, cross-over designed manner: (i) bed rest in normoxia (NBR; PiO2 = 133.1 ± 0.3 mmHg), (ii) bed rest in normobaric hypoxia (HBR; PiO2 = 90.0 ± 0.4 mmHg) and ambulatory confinement in normobaric hypoxia (HAmb; PiO2 = 90.0 ± 0.4 mmHg). Peripheral quantitative computed tomography and vastus lateralis muscle biopsies were performed before and after the interventions to obtain thigh and calf muscle cross-sectional areas and muscle fiber phenotype changes, respectively. A significant reduction of thigh muscle size following NBR (-6.9%, SE 0.8%; P < 0.001) was further aggravated following HBR (-9.7%, SE 1.2%; P = 0.027). Bed rest-induced muscle wasting in the calf was, by contrast, not exacerbated by hypoxic conditions (P = 0.47). Reductions in both thigh (-2.7%, SE 1.1%, P = 0.017) and calf (-3.3%, SE 0.7%, P < 0.001) muscle size were noted following HAmb. A significant and comparable increase in type 2× fiber percentage of the vastus lateralis muscle was noted following both bed rest interventions (NBR = +3.1%, SE 2.6%, HBR = +3.9%, SE 2.7%, P < 0.05). Collectively, these data indicate that hypoxia can exacerbate inactivity-related muscle wasting in healthy active participants and moreover suggest that the combination of both, hypoxemia and lack of activity, as seen in COPD patients, might be particularly harmful for muscle tissue., QC 20180601

Context: Perioperative management of morbidly obese patients undergoing bariatric surgery is challenging. Lacking standardized perioperative protocols, complication rates may be high. This retrospective study aims to quantify the incidence of significant blood pressure decreases on induction of anesthesia and intraoperative hypoxemia, before implementation of a standardized protocol designed for bariatric surgery. Design: Retrospective, observational study. Setting: A 250-bed county hospital in northern Sweden. Subjects: 219 morbidly obese patients (body mass index > 35 kg/m2) who underwent bariatric surgery between 2003 and 2008. Main outcome measures: Incidence of systolic blood pressure (SAP) falls to less than 70% of the preoperative baseline during induction of anesthesia and incidence of perioperative hypoxemia. Results: The incidence of confirmed SAP falls to below 70% of baseline at induction of anesthesia was 56.2% (n = 123/219). This incidence rose with increasing age (p < 0.001) but not with body mass index (BMI). 3.7% (n = 8/219) of cases were marked as difficult intubations. A transient period of hypoxemia was observed in 6.8% (n = 15/219) and was more common with increasing BMI (p = 0.005). Fourteen different drug combinations were used in the study population. Of those administered an induction anesthetic drug, 72.6% (n = 159/193) were given an overdose when calculated by lean body weight, but this did not correlate significantly to SAP falls (p = 0.468). Conclusions: The incidence of a significant blood pressure fall upon induction of anesthesia was common. The incidence of airway and ventilation problems were low. Overdosing of anesthetics and excessive variation in applied anesthesia methods were found.

Patients requiring emergency airway management may be at greater risk of acute hypoxemic events because of underlying lung pathology, high metabolic demands, insufficient respiratory drive, obesity, or the inability to protect their airway against aspiration. Emergency tracheal intubation is often required before complete information needed to assess the risk of procedural hypoxia is acquired (i.e., arterial blood gas level, hemoglobin value, or chest radiograph). During pre-oxygenation, administering high-flow nasal oxygen in addition to a non-rebreather face mask can significantly boost the effective inspired oxygen. Similarly, with the apnea created by rapid sequence intubation (RSI) procedures, the same high-flow nasal cannula can help maintain or increase oxygen saturation during efforts to secure the tube (oral intubation). Thus, the use of nasal oxygen during pre-oxygenation and continued during apnea can prevent hypoxia before and during intubation, extending safe apnea time, and improve first-pass success attempts. We conducted a literature review of nasal-cannula apneic oxygenation during intubation, focusing on two components: oxygen saturation during intubation, and oxygen desaturation time. We performed an electronic literature search from 1980 to November 2017, using PubMed, Elsevier, ScienceDirect, and EBSCO. We identified 14 studies that pointed toward the benefits of using nasal cannula during emergency intubation.

Acute kidney injury (AKI) is a common complication following cardiac surgery performed on cardiopulmonary bypass (CPB) and has important implications for prognosis. The aetiology of cardiac surgery-associated AKI is complex, but renal hypoxia, particularly in the medulla, is thought to play at least some role. There is strong evidence from studies in experimental animals, clinical observations and computational models that medullary ischaemia and hypoxia occur during CPB. There are no validated methods to monitor or improve renal oxygenation during CPB, and thus possibly decrease the risk of AKI. Attempts to reduce the incidence of AKI by early transfusion to ameliorate intra-operative anaemia, refinement of protocols for cooling and rewarming on bypass, optimization of pump flow and arterial pressure, or the use of pulsatile flow, have not been successful to date. This may in part reflect the complexity of renal oxygenation, which may limit the effectiveness of individual interventions. We propose a multi-disciplinary pathway for translation comprising three components. Firstly, large-animal models of CPB to continuously monitor both whole kidney and regional kidney perfusion and oxygenation. Secondly, computational models to obtain information that can be used to interpret the data and develop rational interventions. Thirdly, clinically feasible non-invasive methods to continuously monitor renal oxygenation in the operating theatre and to identify patients at risk of AKI. In this review, we outline the recent progress on each of these fronts.Copyright © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd

Introduction: Hypoxaemia consequent to sleep-disordered breathing, measured using pulse oximetry and quantified by the percentage of total sleep time SpO2 <=90% (T90), increases the risk of all-cause mortality in men, but not women. However, SpO2 values <=90% are rare in women. Here we tested the hypothesis that a greater percentage of total sleep time with SpO2 <=93% (T93) increases mortality risk in women. Method(s): This project retrospectively analysed the Sleep Heart Health Study in which participants >39 years underwent home polysomnography at baseline, with mortality outcomes followed-up for 11 years. Hypoxaemia was quantified by calculating T90 and T93. Cox's proportionate hazard regression described the relationship between hypoxaemia (continuous variables) and mortality, adjusting for covariates (age, race, BMI, smoking status, hypertension, diabetes, cardiovascular disease). Data in women are presented. Result(s): Studies for 2,773 women were available. The crude mortality rate was 19.5%. Cox regression showed that T93 improved the model relative to T90 alone (p < 0.05) and that younger vs. older women had greater hypoxemia-related mortality risk (age x T93 interaction, p < 0.05). Age stratified hazard ratios (95% CI) for 45-60, 60-75 and 75-90 years were: 1.22 (1.11-1.33) per 10% increase in T93, 1.05 (1.01-1.09), and 1.03 (0.99-1.07) respectively. Thus, among women aged 45-60 years, those with T93 = 56% (90th centile of population) have 3 times the mortality risk compared with those with T93 = 0%. Discussion(s): An increased proportion of sleep with relatively mild hypoxaemia (SpO2 <=93%) is associated with increased risk of all-cause mortality in middle-aged women. Quantifying T93, rather than T90, may help identify middle-aged women whose sleep-disordered breathing places them at particular risk of adverse long-term outcomes.

The Chinese population has a comparable prevalence of obstructive sleep apnea (OSA) compared to their Caucasian counterparts, but are notably less obese. Given this difference in body weight, Chinese patients could have a distinct OSA phenotype. We aimed to compare the characteristics of obstructive events in Chinese and Caucasian individuals matched for OSA severity. Chinese and Caucasian subjects with moderate-to-severe OSA (apnea-hypopnea index (AHI) >= 20events/h) were included in the study (n = 90) and matched for age, gender and AHI. Data were analysed to identify differences in event type, effect of sleep state and body position, degree of hypoxemia, and prevalence of metabolic risk factors. Data presented are Mean +/- SEM or Median (IQR). Chinese subjects had a significantly lower body mass index (BMI) compared to AHI-matched Caucasian counterparts [27 (25-30) versus 34 (30-39) kg/m2, p < 0.001]. Chinese subjects had more apneas compared to Caucasian subjects [14.4 (5.8-31.8) versus 8.1 (2.2-20.7) events/h, p = 0.011]. Events were longer in the Chinese group (apnea: 25.1 +/- 1.2 s versus 19.3 +/- 1.3 s, p = 0.001; hypopnea 25.3 +/- 1.0 s versus 22.9 +/- 1.0 s, p = 0.03), but were associated with less hypoxemia (% time < 90%: 14.6 +/- 2.5 versus 25.0 +/- 3.7%, p = 0.01). Chinese individuals with moderate-to-severe OSA have a distinct phenotype characterised by longer and more frequent apneas, yet less hypoxemia, in the setting of a lower BMI, compared to Caucasians of equivalent disease severity. Postulated mechanisms include differing upper airway anatomy, control of breathing or lung reserve.Copyright © 2018, Japanese Society of Sleep Research.

Background Patient safety is a priority in dentistry. Evaluating the benefits and harms associated with the addition of capnography to standard monitoring during moderate sedation for adult patients in the dental practice setting is needed. Types of Studies Reviewed The authors used rapid review methodology to identify relevant systematic reviews, which they updated through a systematic search by using the same search strategy as the identified reviews. The authors searched PubMed and Google Scholar and through the references of the identified systematic reviews, which yielded 2,892 studies. Inclusion criteria were that the article was available in English, was original research in adult humans who had undergone moderate procedural sedation, and involved comparing standard monitoring with the addition of capnography. Results Sixteen studies were eligible, involving 3,866 adults undergoing procedural sedation. The authors used the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the evidence and rate it as being of moderate to low quality because of high risk of bias and heterogeneous effects for the outcomes of hypoxemia and adverse respiratory events. Capnography had higher sensitivity to detect adverse respiratory events than did standard monitoring alone (0.92; 95% confidence interval, 0.65 to 0.99) and may reduce the risk of developing hypoxemia by 31% (risk ratio, 0.69; 95% confidence interval, 0.57 to 0.82). Capnography did not affect the risk of developing serious adverse events, procedure time, sedation quality, or patient satisfaction. Conclusions and Practical Implications Adding capnography to standard monitoring of adults during moderate sedation may reduce the risk of developing hypoxemia, increase detection of adverse respiratory events, and is not associated with additional harms. These findings suggest routine use of capnography during moderate sedation has the potential to reduce adverse anesthetic outcomes in d