OBJECTIVE: Neonatal exposure to episodic hypoxemia and hyperoxemia is highly relevant to outcomes. Our goal was to investigate the differences in the frequency and duration of extreme low and high SpO2 episodes between automated and manual inspired oxygen control. DESIGN: Post-hoc analysis of a cohort from prospective randomized cross-over studies. SETTING: Seven tertiary care neonatal intensive care units. PATIENTS: Fifty-eight very preterm neonates (32 or less weeks PMA) receiving respiratory support and supplemental oxygen participating in an automated versus manual oxygen control cross-over trial. MAIN MEASURES: Extreme hypoxemia was defined as a SpO2 < 80%, extreme hyperoxemia as a SpO2 > 98%. Episode duration was categorized as < 5 seconds, between 5 to < 30 seconds, 30 to < 60 seconds, 60 to < 120 seconds, and 120 seconds or longer. RESULTS: The infants were of a median postmenstrual age of 29 (28-31) weeks, receiving a median FiO2 of 0.28 (0.25-0.32) with mostly receiving non-invasive respiratory support (83%). While most of the episodes were less than 30 seconds, longer episodes had a marked effect on total time exposure to extremes. The time differences in each of the three longest durations episodes (30, 60, and 120 seconds) were significantly less during automated than during manual control (p < 0.001). Nearly two-third of the reduction of total time spent at the extremes between automated and manual control (3.8 to 2.1% for < 80% SpO2 and 3.0 to 1.6% for > 98% SpO2) was seen in the episodes of at least 60 seconds. CONCLUSIONS: This study shows that the majority of episodes preterm infants spent in SpO2 extremes are of short duration regardless of manual or automated control. However, the infrequent longer episodes not only contribute the most to the total exposure, but also their reduction in frequency to the improvement associated with automated control.

• Klíčová slova
• Hyperoxemia episodes, Hypoxemic episodes, Neonatology, Oxygen saturation,
• MeSH
• hypoxie etiologie   terapie   MeSH
• kojenec MeSH
• kyslík * MeSH
• lidé MeSH
• novorozenec nedonošený * MeSH
• novorozenec MeSH
• oxymetrie MeSH
• prospektivní studie MeSH
• retrospektivní studie MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyslík * MeSH

Oxygen is biologically vital element sustaining life. The tissue oxygen delivery is therefore precisely regulated. The degree of tissue oxygenation is estimated by measurement of oxygen blood level. The lack of oxygen on cellular and tissue level can lead to organ failure and life-threatening condition. Important adaptive processes are activated during the sublethal hypoxia with goal to preserve cellular and tissue functions. Inadequate effort to correct hypoxia can cause either disturbance of the adaptation or undesirable tissue hyperoxia. This fact is taken into account in two currently proposed concepts: (1) precise control of arterial oxemia and (2) permissive hypoxemia. Recent literature supports rather restrictive strategy of oxygen therapy in critical care.

• Klíčová slova
• cell adaptation, critical care, hypoxemia, hypoxia, oxygen therapy,
• MeSH
• hyperoxie * MeSH
• hypoxie terapie   MeSH
• kyslík MeSH
• lidé MeSH
• oxygenoterapie * MeSH
• péče o pacienty v kritickém stavu MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyslík MeSH

OBJECTIVE: To identify markers associated with in-hospital death in patients with coronavirus disease 2019 (COVID-19)-associated pneumonia. PATIENTS AND METHODS: A retrospective cohort study was conducted of 140 patients with moderate to critical COVID-19-associated pneumonia requiring oxygen supplementation admitted to the hospital from January 28, 2020, through February 28, 2020, and followed up through March 13, 2020, in Union Hospital, Wuhan, China. Oxygen saturation (SpO2) and other measures were tested as predictors of in-hospital mortality in survival analysis. RESULTS: Of 140 patients with COVID-19-associated pneumonia, 72 (51.4%) were men, with a median age of 60 years. Patients with SpO2 values of 90% or less were older and were more likely to be men, to have hypertension, and to present with dyspnea than those with SpO2 values greater than 90%. Overall, 36 patients (25.7%) died during hospitalization after median 14-day follow-up. Higher SpO2 levels after oxygen supplementation were associated with reduced mortality independently of age and sex (hazard ratio per 1-U SpO2, 0.93; 95% CI, 0.91 to 0.95; P<.001). The SpO2 cutoff value of 90.5% yielded 84.6% sensitivity and 97.2% specificity for prediction of survival. Dyspnea was also independently associated with death in multivariable analysis (hazard ratio, 2.60; 95% CI, 1.24 to 5.43; P=.01). CONCLUSION: In this cohort of patients with COVID-19, hypoxemia was independently associated with in-hospital mortality. These results may help guide the clinical management of patients with severe COVID-19, particularly in settings requiring strategic allocation of limited critical care resources. TRIAL REGISTRATION: Chictr.org.cn Identifier: ChiCTR2000030852.

• MeSH
• Betacoronavirus izolace a purifikace   MeSH
• COVID-19 MeSH
• hodnocení rizik metody   MeSH
• hypoxie * diagnóza   etiologie   terapie   MeSH
• koronavirové infekce * komplikace   diagnóza   mortalita   patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mortalita v nemocnicích MeSH
• oxygenoterapie * metody   statistika a číselné údaje   MeSH
• pandemie * MeSH
• prognóza MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• SARS-CoV-2 MeSH
• spotřeba kyslíku MeSH
• stupeň závažnosti nemoci MeSH
• virová pneumonie * krev   komplikace   diagnóza   etiologie   mortalita   patofyziologie   terapie   MeSH
• výsledky a postupy - zhodnocení (zdravotní péče) MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Čína MeSH

We report a case of a 20-year-old male patient suffering from motorcycle accident complicated by rapid development of severe refractory hypoxemia and hypercapnia due to serious bilateral lung contusions and lacerations. Positive pressure mechanical ventilation induced pressure-dependent massive air leak from disrupted pulmonary tissue. Simultaneous implementation of veno-venous extracorporeal membrane oxygenation together with surfactant application allowed prolonged disconnection of patient from mechanical ventilation ("total lung rest" mode). Despite considerable areas of nonaerated tissue on computed tomography prior to the disconnection from mechanical ventilation, almost total functional recovery of lungs was eventually achieved.

• Klíčová slova
• Acute respiratory distress syndrome, Exogenous surfactant, Extracorporeal membrane oxygenation, Total lung rest,
• MeSH
• hypoxie diagnostické zobrazování   patofyziologie   terapie   MeSH
• lidé MeSH
• mimotělní membránová oxygenace metody   MeSH
• mladý dospělý MeSH
• plíce diagnostické zobrazování   patofyziologie   MeSH
• počítačová rentgenová tomografie MeSH
• povrchově aktivní látky terapeutické užití   MeSH
• syndrom dechové tísně diagnostické zobrazování   patofyziologie   terapie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• povrchově aktivní látky MeSH

BACKGROUND: Respiratory parameters are important predictors of prognosis in the COPD population. Global Initiative for Obstructive Lung Disease (GOLD) 2017 Update resulted in a vertical shift of patients across COPD categories, with category B being the most populous and clinically heterogeneous. The aim of our study was to investigate whether respiratory parameters might be associated with increased all-cause mortality within GOLD category B patients. METHODS: The data were extracted from the Czech Multicentre Research Database, a prospective, noninterventional multicenter study of COPD patients. Kaplan-Meier survival analyses were performed at different levels of respiratory parameters (partial pressure of oxygen in arterial blood [PaO2], partial pressure of arterial carbon dioxide [PaCO2] and greatest decrease of basal peripheral capillary oxygen saturation during 6-minute walking test [6-MWT]). Univariate analyses using the Cox proportional hazard model and multivariate analyses were used to identify risk factors for mortality in hypoxemic and hypercapnic individuals with COPD. RESULTS: All-cause mortality in the cohort at 3 years of prospective follow-up reached 18.4%. Chronic hypoxemia (PaO2 <7.3 kPa), hypercapnia (PaCO2 >7.0 kPa) and oxygen desaturation during the 6-MWT were predictors of long-term mortality in COPD patients with forced expiratory volume in 1 second ≤60% for the overall cohort and for GOLD B category patients. Univariate analyses confirmed the association among decreased oxemia (<7.3 kPa), increased capnemia (>7.0 kPa), oxygen desaturation during 6-MWT and mortality in the studied groups of COPD subjects. Multivariate analysis identified PaO2 <7.3 kPa as a strong independent risk factor for mortality. CONCLUSION: Survival analyses showed significantly increased all-cause mortality in hypoxemic and hypercapnic GOLD B subjects. More important, PaO2 <7.3 kPa was the strongest risk factor, especially in category B patients. In contrast, the majority of the tested respiratory parameters did not show a difference in mortality in the GOLD category D cohort.

• Klíčová slova
• COPD, GOLD 2017 update, hypercapnia, hypoxemia, mortality,
• MeSH
• analýza krevních plynů MeSH
• chronická obstrukční plicní nemoc diagnóza   mortalita   patofyziologie   terapie   MeSH
• databáze faktografické MeSH
• dýchání * MeSH
• hyperkapnie diagnóza   mortalita   patofyziologie   terapie   MeSH
• hypoxie diagnóza   mortalita   patofyziologie   terapie   MeSH
• Kaplanův-Meierův odhad MeSH
• komorbidita MeSH
• lidé středního věku MeSH
• lidé MeSH
• multivariační analýza MeSH
• plíce patofyziologie   MeSH
• prediktivní hodnota testů MeSH
• prognóza MeSH
• proporcionální rizikové modely MeSH
• rizikové faktory MeSH
• senioři MeSH
• stupeň závažnosti nemoci MeSH
• test chůzí MeSH
• usilovný výdechový objem MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

BACKGROUND: In immunocompromised patients with acute hypoxemic respiratory failure (ARF), initial management aims primarily to avoid invasive mechanical ventilation (IMV). METHODS: To assess the impact of initial management on IMV and mortality rates, we performed a multinational observational prospective cohort study in 16 countries (68 centers). RESULTS: A total of 1611 patients were enrolled (hematological malignancies 51.9%, solid tumors 35.2%, systemic diseases 17.3%, and solid organ transplantation 8.8%). The main ARF etiologies were bacterial (29.5%), viral (15.4%), and fungal infections (14.7%), or undetermined (13.2%). On admission, 915 (56.8%) patients were not intubated. They received standard oxygen (N = 496, 53.9%), high-flow oxygen (HFNC, N = 187, 20.3%), noninvasive ventilation (NIV, N = 153, 17.2%), and NIV + HFNC (N = 79, 8.6%). Factors associated with IMV included age (hazard ratio = 0.92/year, 95% CI 0.86-0.99), day-1 SOFA (1.09/point, 1.06-1.13), day-1 PaO2/FiO2 (1.47, 1.05-2.07), ARF etiology (Pneumocystis jirovecii pneumonia (2.11, 1.42-3.14), invasive pulmonary aspergillosis (1.85, 1.21-2.85), and undetermined cause (1.46, 1.09-1.98). After propensity score matching, HFNC, but not NIV, had an effect on IMV rate (HR = 0.77, 95% CI 0.59-1.00, p = 0.05). ICU, hospital, and day-90 mortality rates were 32.4, 44.1, and 56.4%, respectively. Factors independently associated with hospital mortality included age (odds ratio = 1.18/year, 1.09-1.27), direct admission to the ICU (0.69, 0.54-0.87), day-1 SOFA excluding respiratory score (1.12/point, 1.08-1.16), PaO2/FiO2 < 100 (1.60, 1.03-2.48), and undetermined ARF etiology (1.43, 1.04-1.97). Initial oxygenation strategy did not affect mortality; however, IMV was associated with mortality, the odds ratio depending on IMV conditions: NIV + HFNC failure (2.31, 1.09-4.91), first-line IMV (2.55, 1.94-3.29), NIV failure (3.65, 2.05-6.53), standard oxygen failure (4.16, 2.91-5.93), and HFNC failure (5.54, 3.27-9.38). CONCLUSION: HFNC has an effect on intubation but not on mortality rates. Failure to identify ARF etiology is associated with higher rates of both intubation and mortality. This suggests that in addition to selecting the appropriate oxygenation device, clinicians should strive to identify the etiology of ARF.

• Klíčová slova
• Hematological malignancies, High flow oxygen, Noninvasive ventilation, Pneumocystis, Systemic diseases, Transplantation,
• MeSH
• hypoxie mortalita   terapie   MeSH
• imunokompromitovaný pacient * MeSH
• intratracheální intubace škodlivé účinky   MeSH
• komorbidita MeSH
• kritický stav MeSH
• lidé středního věku MeSH
• lidé MeSH
• mortalita v nemocnicích MeSH
• neinvazivní ventilace metody   MeSH
• oxygenoterapie metody   MeSH
• prospektivní studie MeSH
• respirační insuficience etiologie   mortalita   terapie   MeSH
• senioři MeSH
• stupeň závažnosti nemoci MeSH
• věkové faktory MeSH
• vyhodnocení orgánové dysfunkce MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• pozorovací studie MeSH

RATIONALE: High-frequency oscillatory ventilation (HFOV) is theoretically beneficial for lung protection, but the results of clinical trials are inconsistent, with study-level meta-analyses suggesting no significant effect on mortality. OBJECTIVES: The aim of this individual patient data meta-analysis was to identify acute respiratory distress syndrome (ARDS) patient subgroups with differential outcomes from HFOV. METHODS: After a comprehensive search for trials, two reviewers independently identified randomized trials comparing HFOV with conventional ventilation for adults with ARDS. Prespecified effect modifiers were tested using multivariable hierarchical logistic regression models, adjusting for important prognostic factors and clustering effects. MEASUREMENTS AND MAIN RESULTS: Data from 1,552 patients in four trials were analyzed, applying uniform definitions for study variables and outcomes. Patients had a mean baseline PaO2/FiO2 of 114 ± 39 mm Hg; 40% had severe ARDS (PaO2/FiO2 <100 mm Hg). Mortality at 30 days was 321 of 785 (40.9%) for HFOV patients versus 288 of 767 (37.6%) for control subjects (adjusted odds ratio, 1.17; 95% confidence interval, 0.94-1.46; P = 0.16). This treatment effect varied, however, depending on baseline severity of hypoxemia (P = 0.0003), with harm increasing with PaO2/FiO2 among patients with mild-moderate ARDS, and the possibility of decreased mortality in patients with very severe ARDS. Compliance and body mass index did not modify the treatment effect. HFOV increased barotrauma risk compared with conventional ventilation (adjusted odds ratio, 1.75; 95% confidence interval, 1.04-2.96; P = 0.04). CONCLUSIONS: HFOV increases mortality for most patients with ARDS but may improve survival among patients with severe hypoxemia on conventional mechanical ventilation.

• Klíčová slova
• acute respiratory distress syndrome, high-frequency oscillatory ventilation, mechanical ventilation,
• MeSH
• dospělí MeSH
• hypoxie terapie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• syndrom dechové tísně terapie   MeSH
• umělé dýchání metody   MeSH
• výsledek terapie MeSH
• vysokofrekvenční ventilace metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• metaanalýza MeSH
• srovnávací studie MeSH

The aim of the study was to determine the dependence of changes in the electrical stability of the heart on the light-dark cycle (LD cycle) in disorders of pulmonary ventilation. The ventricular arrhythmia threshold (VAT) was measured in female Wistar rats (adaptation to the light regime 12:12 h, ketamine/xylazine anesthesia 100 mg/15 mg/kg, i.m., open chest experiments). The conditions of the normal artificial ventilation and reoxygenation were V(T) = 1 ml/100 g, respiratory rate 40 breaths/min, hypoventilation V(T) = 0.5 ml/100 g, respiratory rate 20 breaths/min. The animals (n=11 light group; n=19 dark group) were subjected to 20 min hypoventilation followed by 20 min reoxygenation. The control prehypoventilatory VAT differences were not found between the light (1.90+/-0.84 mA) and dark (1.88+/-0.87 mA) part of the day. Artificial hypoventilation changed the VAT values in light and dark part of the day differently. While during the light period, the average VAT values in most animals (90.9 %) were significantly decreased (1.29+/-0.59 vs. 1.90+/-0.84 mA control, p<0.05), during the dark part these values showed either significant increase (63.2 %) (2.23+/-0.77 vs. 1.48+/-0.39 mA, p<0.005) or a slight non-significant decrease (36.8 %) (2.18+/-0.89 vs. 2.54+/-0.99 mA). Reoxygenation returned the VAT values to the level before hypoventilation by an increase of the VAT (81.8 %) in the light part of day and by decrease of the VAT (68.4 %) in the dark part of the day. It is concluded that 1) in hypoventilation/reoxygenation model, the significant higher average VAT values are in the dark part of the day vs. the light one, 2) rat hearts are more resistant to systemic hypoxia and reoxygenation in the dark part of day, and 3) proarrhythmogenic effect of the systemic hypoxia is only seen in the light part of the day.

• MeSH
• cirkadiánní rytmus * MeSH
• hypoxie komplikace   patofyziologie   terapie   MeSH
• komorová tachykardie etiologie   patofyziologie   MeSH
• krysa rodu Rattus MeSH
• kyslík metabolismus   MeSH
• potkani Wistar MeSH
• převodní systém srdeční patofyziologie   MeSH
• umělé dýchání * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyslík MeSH

Various cardiorespiratory and electrophysiological parameters were analysed in a model of acute respiratory failure induced by inhalation of pure nitrogen in approximately 150 anaesthetized cats. Initial hyperventilation leading to apnoea was characterized by extreme hypoxaemia, marked bradycardia and flattening of electrocortical (ECoG) activity. Artificial ventilation applied at the stage of marked mydriasis usually spontaneously prevented cardiovascular failure and normalized vital functions. Up to seven successive apnoeic attacks could be induced in the same cat. During the first 30 or 60 s of apnoea, nasopharyngeal stimulation usually elicited a typical gasp-like aspiration reflex, while tracheobronchial stimulation provoked a weak cough only in 28 and 34% of cases for 30- and 60-s apnoea, respectively. The aspiration reflex could be elicited at very low and even isoelectric ECoG activity, and its periodic provocation (without artificial ventilation) resulted, more frequently than did gasping, in recovery from hypoxic apnoea. Arousal and resuscitation induced by the aspiration reflex can provide a useful model to study the mechanisms of reversible respiratory failure and restitution of vital functions.

• MeSH
• anestezie MeSH
• aplikace inhalační MeSH
• apnoe etiologie   terapie   MeSH
• dusík MeSH
• elektrokardiografie MeSH
• fyzikální stimulace MeSH
• hypoxie etiologie   terapie   MeSH
• kočky MeSH
• modely nemocí na zvířatech MeSH
• nadechnutí fyziologie   MeSH
• nazofarynx MeSH
• reflex fyziologie   MeSH
• respirační insuficience etiologie   terapie   MeSH
• resuscitace metody   MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dusík MeSH

• MeSH
• hyperbarická oxygenace * MeSH
• hypoxie prevence a kontrola   terapie   MeSH
• kyslík škodlivé účinky   MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyslík MeSH