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Uterine contractions during labor and engagement of the fetus in the birth canal can compress the fetal head. Its impact on the fetus is unclear and still controversial. In this integrative physiological review, we highlight evidence that decelerations are uncommonly associated with fetal head compression. Next, the fetus has an impressive ability to adapt to increased intracranial pressure through activation of the intracranial baroreflex, such that fetal cerebral perfusion is well-maintained during labor, except in the setting of prolonged systemic hypoxemia leading to secondary cardiovascular compromise. Thus, when it occurs, fetal head compression is not necessarily benign but does not seem to be a common contributor to intrapartum decelerations. Finally, the intracranial baroreflex and the peripheral chemoreflex (the response to acute hypoxemia) have overlapping efferent effects. We propose the hypothesis that these reflexes may work synergistically to promote fetal adaptation to labor.

IntroductionCentral airway tumors involving the trachea and main-stem bronchi are a common cause of airway obstruction and a significant cause of mortality among the patients of thoracic diseases with respiratory failure. Debulking in rigid bronchoscopy is quick, safe, and effective. It can be complex and hard in patients with severe bronchial or tracheal obstruction and/or with intraluminal bleeding tumors because of inadequate distal airway control. We have used laser tube as a new technique of ventilation for severe central airway obstruction.Materials and MethodsForty-six patients with severe airway obstruction undergoing rigid bronchoscopy from September 2020 to June 2022 at the Thoracic Surgery Department of the University L. Vanvitelli of Naples underwent placement of laser tube.ResultsIn all patients who underwent rigid bronchoscopy with the use of the laser tube, a reduction of obstruction of more than 50% was obtained and in all patients no hypoxia (saturation < 88%), nor hypercapnia, nor significant bleeding were reported.DiscussionThe results of this study suggest that rigid bronchoscopic debulking with the use of laser tube is a safe and effective technique in the management of central airway obstruction.ConclusionsThe use of the laser tube allows the monitoring of gas exchange, which controls hypoxemia. Thanks to the double cuff put distally to the tracheal obstruction or in the contralateral bronchus to the obstructed one, the laser tube prevents the flooding of blood from debulking below the stenosis. Rigid bronchoscopy with laser tube will expand its use in the future.

Introduction Surgery is one of the most frequently used options in the treatment of head and neck squamous cell carcinoma. In surgical patients, the use of arterial lactate to assess hypoxemia and severe inflammatory states is well-founded. However, there are few studies on its use in patients with head and neck squamous cell carcinoma. The aim of this study was to investigate whether the serum arterial lactate level on the 1st postoperative day would be a predictor of postoperative complications in head and neck squamous cell carcinoma surgeries. Methods This is a prospective cohort, which evaluated 44 adult patients of both genders, with HNSCC, who underwent surgery associated with monobloc neck dissection as an initial treatment. Patients were divided into two groups, according to the presence or absence of postoperative complications: with complication (Clavien-Dindo II-V) and without complications (Clavien-Dindo 0-I). Student’s t-test and its variants were used to compare continuous data. Pearson’s or Spearman’s test was used to correlate the data and p values 1.7 mmoL/L was identified, with a sensitivity of 65.38% and specificity of 66.67%. Conclusion Arterial lactate measured on the first postoperative day is a good predictor of postoperative complications in patients with head and neck squamous cell carcinoma. Resumo Introdução A cirurgia é uma das opções mais usadas no tratamento do carcinoma epidermoide de cabeça e pescoço. Nos pacientes cirúrgicos, o uso do lactato arterial para avaliação de hipoxemia e de quadros inflamatórios graves é bem fundamentado. Entretanto, existem poucos estudos sobre o seu uso em pacientes com carcinoma epidermoide de cabeça e pescoço. O objetivo deste estudo foi investigar se o lactato arterial sérico no 1° dia de pós‐operatório seria um preditor de complicações pós‐operatórias nas cirurgias do carcinoma epidermoide de cabeça e pescoço. Método Trata‐se de uma coorte prospectiva, que avaliou 44 pacientes adultos, de ambos os gêneros, com carcinoma epidermoide de cabeça e pescoço, submetidos a cirurgia associada ao esvaziamento cervical em monobloco como tratamento inicial. Os pacientes foram divididos em dois grupos, segundo a presença ou não de complicações pós‐operatórias: complicados (Clavien‐Dindo II a V) e sem complicações (Clavien‐Dindo 0-I). Na comparação dos dados contínuos, foi usado o teste t de Student e as suas variantes. Na correlação dos dados, usou‐se o teste de Pearson ou Spearman. Valores de p inferiores a 0,05 (p < 0,05) foram considerados estatisticamente significativos. Resultados Dos pacientes, 59% (n = 26/44) desenvolveram complicações pós‐operatórias. O lactato sérico foi significantemente maior no grupo com complicações em relação aos pacientes sem complicações, respectivamente 2,15 mmoL/L (1,10-3,90) e 1,59 mmoL/L (0,70-3,44); p = 0,03. A acurácia prognóstica do lactato arterial foi de 69% (95% IC 54%-82%; p = 0,03), estimada pela curva ROC. Foi identificado um cut‐off> 1,7 mmoL/L, com sensibilidade de 65,38% e especificidade de 66,67%. Conclusão O lactato arterial do primeiro dia de pós‐operatório é um bom preditor de complicações pós‐operatórias nos pacientes com carcinoma epidermoide de cabeça e pescoço.

The oxygen content in the blood may decrease under the influence of various physicochemical factors and different diseases. The state of hypoxemia is especially dangerous for critically ill patients. In this paper, we describe and analyze the changes in the characteristics of red blood cells (RBCs) with decreasing levels of oxygen in the RBC suspension from normoxemia to hypoxemia/anoxemia in an in vitro model experiment. The RBCs were stored in hypoxemia/anoxemia and normoxemia conditions in closed and open tubes correspondingly. For the quantitative study of RBC parameter changes, we used atomic force microscopy, digital spectrophotometry, and nonlinear curve fitting of the optical spectra. In both closed and open tubes, at the end of the storage period by day 29, only 2% of discocytes remained, and mainly irreversible types, such as microspherocytes and ghosts, were observed. RBC hemolysis occurred at a level of 25–30%. Addition of the storage solution, depending on the concentration, changed the influence of hypoxemia on RBCs. The reversibility of the change in hemoglobin derivatives was checked. Based on the experimental data and model approach, we assume that there is an optimal level of hypoxemia at which the imbalance between the oxidative and antioxidant systems, the rate of formation of reactive oxygen species, and, accordingly, the disturbances in RBCs, will be minimal.

Background: Nocturnal hypoxaemia measured as the percentage of total sleep time spent with saturation below 90% (TST90%) may better predict cardiovascular consequences of obstructive sleep apnoea (OSA) than the number of obstructive respiratory events measured with the apnoea–hypopnea index (AHI). Deeper hypoxaemia may potentially induce more severe pathophysiological consequences. However, the additional value of the percentage of total sleep time spent with saturation below 80% (TST80%) to TST90% is not fully explored. Methods: Comprehensive medical history was taken and fasting lipid and C-reactive protein levels were measured in 797 volunteers participating in two cohort studies in Hungary and Romania. Sleep parameters, including AHI, TST90% and TST80%, were recorded following a polysomnography (PSG, n = 598) or an inpatient cardiorespiratory polygraphy (n = 199). The performance of TST80% to predict cardiovascular risk was compared with TST90% using linear and logistic regression analyses as well receiver operating characteristics curves. Sensitivity analyses were performed in patients who had PSG, separately. Results: Both parameters are significantly related to cardiovascular risk factors; however, TST80% did not show better predictive value for cardiovascular risk than TST90%. On the other hand, patients with more severe hypoxaemia reported more excessive daytime sleepiness. Conclusions: TST80% has limited additional clinical value compared to TST90% when evaluating cardiovascular risk in patients with OSA.

Aim: In the clinical course of Chronic Obstructive Pulmonary Disease (COPD), exacerbations thatare defined as worsening of respiratory symptoms (dyspnoea, cough, sputum production) may occur,which causes poor prognosis and require additional treatments. Cost-effective mortality predictors arevaluable for the treatment management of COPD. We aimed to investigate whether serum uric acid(UA) and serum uric acid to creatinine ratio (UCR) are predictors of mortality and hypoxemia in patientswith acute exacerbations of COPD (AECOPD).Material and Methods: 105 patients with AECOPD who were hospitalized in a reference chest hospitalbetween January 2014 and December 2018 were evaluated retrospectively in this cross-sectional study.The associations between UA and UCR and long-term mortality, hypoxemia, comorbidity, FEV1 value,and Global Strategy for the Diagnosis, Management and Prevention of Chronic Obstructive PulmonaryDisease (GOLD) stage were analyzed.Results: In the present study including 105 patients with AECOPD (97 males, mean age of 65±9 years),a significant correlation was found between hyperuricemia and mortality (95% CI:1.15-10.72, p=0.027;95% CI:1.16-4.12, p=0.016, respectively), while no correlation was found between UCR and mortality(p=0.051, p=0.053, respectively). Low UA level was associated with hypoxemia significantly (p=0.022),but no association was observed between UCR and hypoxemia (p=0.094).Conclusion: It appears that UA is more important for predicting long-term mortality in patients withAECOPD than UCR. We suggest that UA can be used as a biomarker of long-term mortality for theidentification of high-risk COPD patients that require frequent clinical follow-up and intense treatmentmanagement., Amaç: Kronik Obstrüktif Akciğer Hastalığı (KOAH) klinik seyrinde, kötü prognoza neden olan, ektedavi gerektiren, solunum semptomlarında (dispne, öksürük, balgam) kötüleşme olarak tanımlananalevlenmeler gözlenebilir. Maliyet-etkin mortalite öngörücüleri, KOAH’ın tedavi yönetimi için değerlidir.Akut KOAH alevlenmeleri olan serum ürik asit (ÜA) ve serum ürik asitin kreatinine oranının (ÜKO) mortalite ve hipoksemi için belirleyici olupolmadığını araştırmayı amaçladık.Gereç ve Yöntemler: Bu gözlemsel kesitsel çalışmada, Ocak 2014 ile Aralık 2018 arasında bir referans göğüs hastanesinde yatan 105KOAH alevlenmesindeki hasta retrospektif olarak değerlendirildi. ÜA ve ÜKO ile uzun vadeli mortalite, hipoksemi, komorbidite, FEV1 değeri,KOAH’ın tanı, tedavi ve önlenmesi için küresel strateji (GOLD) evreleri arasındaki ilişkiler analiz edildi.Bulgular: KOAH alevlenmesindeki toplam 105 hastayı (97’si erkek, ortalama yaş 65±9 yıl) içeren bu çalışmada hiperürisemi ile mortalitearasında anlamlı bir korelasyon bulunurken (sırasıyla, p=0.027; p=0.016), ÜKO ile mortalite arasında korelasyon bulunmadı (sırasıyla,p=0.051, p=0.053). Düşük ÜA seviyesi hipoksemi ile anlamlı olarak ilişkiliydi (p=0.022), ancak ÜKO ile hipoksemi arasında bir ilişki gözlenmedi(p=0.094).Sonuç: KOAH alevlenmesindeki hastaların uzun vadeli mortalitesini öngörmede serum ÜA’nin ÜKO’na göre daha değerli olduğugörülmektedir. Sık klinik takip ve yoğun tedavi yönetimi gerektiren yüksek riskli KOAH hastalarının tanımlanması için serum ÜA’in uzunvadeli mortalitenin biyobelirteci olarak kullanılabileceğini öneriyoruz.

Uma parcela considerável (63%) de pessoas acometidas pelas formas moderada e grave da COVID-19 desenvolve sequelas que podem levar à disfunção respiratória, dispneia e baixos níveis da saturação arterial de oxigênio. Devido à carência de recursos terapêuticos para suprir a demanda de pacientes com sequelas pós-COVID-19, o Biomagnetismo Medicinal pode ser recurso auxiliar no processo de redução de danos e reabilitação.Objetivo:Relatar um tratamento com Biomagnetismo Medicinal de uma paciente com baixo nível de saturação arterial de oxigênio, devido sequela pós-COVID-19.Método:Estudo descritivo transversal, de caráter exploratório, do tipo relato de caso. Análise comparativa entre a teoria e a prática apurada no prontuário de uma paciente submetida ao tratamento de Biomagnetismo Medicinal por um período de três meses, com queixa de baixo nível de saturação arterial de oxigênio persistente, resultante de sequela respiratória pós-COVID-19.Resultados:A análise do prontuário revelou melhora progressiva nos níveis de saturação de oxigênio da paciente, com alívio na sintomatologia respiratória ao término do tratamento.Considerações finais:O Biomagnetismo Medicinal é um grande aliado no enfrentamento dos problemas de saúde apresentados por pacientes com sequelas respiratórias pós-COVID-19.

We report a clinically significant right-to-left intracardiac shunt through a patent foramen ovale, diagnosed during investigations for hypoxemia and left ventricular dilation on the late postoperative period of a HeartMate3 implantation. We discuss diagnostic pitfalls and haemodynamic influences in this scenario, as well as the possibility of successful percutaneous treatment.

In 1967, Ashbaugh et al. published in the Lancet the description of a new entity, for which they coined the name "adult respiratory distress syndrome". On that article, they thoroughly described 12 patients who had respiratory distress with bilateral pulmonary infiltrates and oxygen therapy-refractory hypoxemia. For its management, emphasis was made on the importance of intubation and mechanical ventilation with positive end-expiratory pressure. At 50 years of its first publication, great advances on the knowledge of this condition have been achieved, which has influenced on patient management and survival. To celebrate this 50th anniversary, the National Academy of Medicine of Mexico organized a symposium with the purpose to spread the knowledge about this condition, recognize the researchers who made the original description and those who over the course of 50 years of history have contributed to its better understanding. The symposium addressed the topics of lung-kidney interaction, molecular bases of the disease and therapeutic advances.

A 3-year-old Chihuahua was presented because of exercise intolerance, respiratory distress, and syncopal episodes. At the age of 10 weeks, the dog was diagnosed with a congenital small left-to-right shunting ventricular septal defect and a mild right ventricular outflow tract obstruction via echocardiography. At that time, the dog was asymptomatic, but the breeder’s veterinarian heard a murmur. Both cardiac defects were judged to be clinically non-relevant at that time. However, at 3 years of age, echocardiography revealed a severe right ventricular obstruction, known as a double-chambered right ventricle, along with right-to-left shunting via the ventricular septal defect. Because of chronic hypoxemia due to the right-to-left shunting, erythrocytosis developed. Flow reversal via the shunt was caused by a progressively worsening right ventricular obstruction leading to a supra-systemic right ventricular systolic pressure. Because of the poor prognosis, the dog was euthanized, and the heart was submitted for post-mortem examination. Gross pathologic findings revealed the close proximity of the right ventricular obstructive lesion to the ventricular septal defect. Histopathology revealed localized muscular hypertrophy and severe endocardial fibrosis. The suspected pathogenesis of the progressive obstruction was infiltrative myocardial fibrosis due to turbulent blood flow from the left-to-right shunting ventricular septal defect, as described in humans.

STUDY OBJECTIVES: Biological models suggest that obstructive sleep apnea (OSA) is potentially carcinogenic. We aimed to clarify the inconsistent epidemiological literature by considering various traditional and novel OSA severity indices. METHODS: We systematically searched PubMed, Embase, Scopus, and the Cochrane Library for observational or randomized studies of associations of OSA, measured by diagnostic codes or any index, each with all-cancer incidence or mortality in adults, compared with participants with no/mild OSA. Two reviewers independently selected studies, extracted data, and evaluated study bias using the Newcastle-Ottawa scale and quality of evidence using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). We performed inverse variance-weighted, random-effects meta-analyses and sensitivity analyses. RESULTS: We included 20 observational studies (5,340,965 participants), all with moderate/low bias, from 1,698 records. Based on T90 (sleep duration with oxygen saturation < 90%), patients with OSA who had moderate (T90 > 1.2%, hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.07–1.54) and severe nocturnal hypoxemia (T90 > 12%, HR = 1.43, 95% CI = 1.16–1.76) experienced 30%–40% higher pooled all-cancer risk than normoxemic patients, after multiple adjustment for covariates including obesity. Furthermore, severe nocturnal hypoxemia nearly tripled all-cancer mortality (HR = 2.66, 95% CI = 1.21–5.85). Patients with apnea-hypopnea index–defined severe OSA, but not moderate OSA, had higher all-cancer risk (HR = 1.18, 95% CI = 1.03–1.35) but similar all-cancer mortality as patients without OSA. An OSA diagnosis was not associated with all-cancer risk. Evidence quality ranged from low to moderate. Insufficient evidence was available on the oxygen desaturation index, lowest/median saturation, and arousal index. CONCLUSIONS: In patients with OSA, nocturnal hypoxemia is independently associated with all-cancer risk and mortality. Future studies should explore if risk differs by cancer type, and whether cancer screening and OSA treatment are beneficial. SYSTEMATIC REVIEW REGISTRATION: Registry: PROSPERO; URL: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=220836; Identifier: CRD42021220836. CITATION: Tan BKJ, Teo YH, Tan NKW, et al. Association of obstructive sleep apnea and nocturnal hypoxemia with all-cancer incidence and mortality: a systematic review and meta-analysis. J Clin Sleep Med. 2022;18(5):1427–1440.

Background Pulse oximeters may produce less accurate results in non-White patients. Research Question Do pulse oximeters detect arterial hypoxemia less effectively in Black, Hispanic, and/or Asian patients than in White patients in respiratory failure and about to undergo extracorporeal membrane oxygenation (ECMO)? Study Design and Methods Data on adult patients with respiratory failure readings 6 h before ECMO from 324 centers, January 2019 to July 2020, were provided by the Extracorporeal Life Support Organization registry. Our primary analysis was of rates of occult hypoxemia—low arterial oxygen saturation (Sa o 2 ≤ 88%) on arterial blood gas measurement despite a pulse oximetry reading in the range of 92% to 96%. Results The rate of pre-ECMO occult hypoxemia, that is, arterial oxygen saturation (Sa o 2) ≤ 88%, was 10.2% (95% CI, 6.2%-15.3%) for 186 White patients with peripheral oxygen saturation (Sp o 2) of 92% to 96%; 21.5% (95% CI, 11.3%-35.3%) for 51 Black patients (P = .031 vs White); 8.6% (95% CI, 3.2%-17.7%) for 70 Hispanic patients (P = .693 vs White); and 9.2% (95% CI, 3.5%-19.0%) for 65 Asian patients (P = .820 vs White). Black patients with respiratory failure had a statistically significantly higher risk of occult hypoxemia with an OR of 2.57 (95% CI, 1.12-5.92) compared with White patients (P = .026). The risk of occult hypoxemia for Hispanic and Asian patients was equivalent to that of White patients. In a secondary analysis of patients with Sa o 2 ≤ 88% despite Sp o 2 > 96%, Black patients had more than three times the risk compared with White patients (OR, 3.52; 95% CI, 1.12-11.10; P = .032). Interpretation Compared with White patients, the prevalence of occult hypoxemia was higher in Black patients than in White patients about to undergo ECMO for respiratory failure, but it was comparable in Hispanic and Asian patients compared with White patients.

Congenital central hypoventilation syndrome is a rare genetic disorder affecting ventilatory response to hypercapnia and/or hypoxemia. We describe a case of diaphragm pacing (DP) failure in a 38-year-old woman with congenital central hypoventilation syndrome who used DP as ventilatory support only during sleep for 24 years. Diagnostic evaluation began with examination of external DP equipment, but adjustment did not elicit adequate diaphragm contractions. Clinical evaluation and transtelephonic monitoring showed absent function of the right pacer and diminished function of the left pacer. The patient had surgical exploration of her internal DP components. The operation revealed that the right pacer receiver had significant circumferential calcium accumulation. After replacement of the receivers in subcutaneous pockets closer to the skin surface, robust diaphragm contractions bilaterally occurred with stimulation. This case suggests DP failure can result from development of calcification and increased distance from the skin surface to the receivers due to weight gain. CITATION: Kwon A, Lodge M, McComb JG, et al. An unusual cause of diaphragm pacer failure in congenital central hypoventilation syndrome. J Clin Sleep Med. 2022;18(3):949–952.

Rapid evolution of pulmonary complications associated with severe COVID-19 pneumonia often pose a management challenge to clinicians especially in the critical care setting. Serial chest imaging enable clinicians to better monitor disease progression and identify potential complications early which may decrease the mortality and morbidity associated with COVID-19. We report a case of severe COVID-19 pneumonia in a 69-year-old man that presented to University Malaya Medical Centre in March 2020 with multiple pulmonary complications including lung cavitation, bronchopleural fistula, pneumothorax, pneumomediastinum, subcutaneous emphysema and acute pulmonary embolism which we highlight through serial chest radiographs (CXR) and computed tomography (CT). The patient unfortunately succumbed to his disease one month after admission. COVID-19 patients may develop pulmonary complications due to a combination of direct viral lung damage, hypoxemia and high stress ventilation. Awareness of COVID-19 complications can prompt early diagnosis and timely management to reduce morbidity and mortality. Keywords: COVID-19 case report, lung cavitation, bronchopleural fistula, pneumothorax, pneumomediastinum.

Background and Purpose: Acute respiratory distress syndrome (ARDS) is characterized by pulmonary oedema and severe hypoxaemia. We investigated whether genetic deficit or blockade of calcium-activated potassium (K Ca3.1) channels would counteract pulmonary oedema and hypoxaemia in ventilator-induced lung injury, an experimental model for ARDS. Experimental Approach: K Ca3.1 channel knockout (Kccn4 -/-) mice were exposed to ventilator-induced lung injury. Control mice exposed to ventilator-induced lung injury were treated with the K Ca3.1 channel inhibitor, senicapoc. The outcomes were oxygenation (PaO 2/FiO 2 ratio), lung compliance, lung wet-to-dry weight and protein and cytokines in bronchoalveolar lavage fluid (BALF). Key Results: Ventilator-induced lung injury resulted in lung oedema, decreased lung compliance, a severe drop in PaO 2/FiO 2 ratio, increased protein, neutrophils and tumour necrosis factor-alpha (TNF-α) in BALF from wild-type mice compared with Kccn4 -/- mice. Pretreatment with senicapoc (10–70 mg·kg −1) prevented the reduction in PaO 2/FiO 2 ratio, decrease in lung compliance, increased protein and TNF-α. Senicapoc (30 mg·kg −1) reduced histopathological lung injury score and neutrophils in BALF. After injurious ventilation, administration of 30 mg·kg −1 senicapoc also improved the PaO 2/FiO 2 ratio and reduced lung injury score and neutrophils in the BALF compared with vehicle-treated mice. In human lung epithelial cells, senicapoc decreased TNF-α-induced permeability. Conclusions and Implications: Genetic deficiency of K Ca3.1 channels and senicapoc improved the PaO 2/FiO 2 ratio and decreased the cytokines after a ventilator-induced lung injury. Moreover, senicapoc directly affects lung epithelial cells and blocks neutrophil infiltration in the injured lung. These findings indicate that blocking K Ca3.1 channels is a potential treatment in ARDS-like disease.

Noninvasive ventilation (NIV) provides respiratory support without the use of invasive ventilation with techniques that do not bypass the upper airway. NIV is particularly attractive given its associated reduced risk of complications associated with intubation. Available NIV modes include nasal cannula, simple mask, nonrebreather, high flow nasal cannula, continuous positive airway pressure (CPAP), and bilevel positive airway pressure. Acute exacerbation of COPD, cardiogenic pulmonary edema, and COVID-19 are conditions for which NIV has shown to be beneficial, whereas there is no consensus among the use of NIV in trauma patients and ARDS.

An 89-year-old woman was admitted to our hospital for subacute onset of right upper and lower limb weakness and was diagnosed with acute cerebral infarction. During rehabilitation, close observation revealed that her oxygen saturation decreased in the sitting position and improved in the recumbent position without any subjective symptoms of dyspnea. Transthoracic and transesophageal echocardiography and cardiac catheterization revealed a large patent foramen ovale with an atrial septal aneurysm with right-to-left shunting through the defect, and she was diagnosed with platypnea-orthodeoxia syndrome. Her right hemiplegia caused the trunk to collapse, so the patient slumped when in sitting position, and the trunk tilted to the right forward, resulting in an increased right-to-left shunt. Her peripheral capillary oxygen saturation improved in the upright sitting position supported by therapists. This case suggests that right hemiplegia may exacerbate the symptoms of platypnea-orthodeoxia syndrome.

There has been strong evidence of myocardial injury in coronavirus disease 2019 (COVID-19) patients with significantly elevated serum cardiac troponin (cTn). While the exact mechanism of injury is unclear, possible suggested pathological mechanisms of injury are discussed. These include increased susceptibility of the myocardium and endothelium to viral invasion, underlying hyperinflammatory state and subsequent cytokine storm, a hypercoagulable and prothrombotic state, and indirect myocardial injury due to hypoxemia. As a result of these pathological mechanisms in COVID-19 patients, cTn may be elevated largely due to myocarditis, microangiopathy or myocardial infarction. The utility of cTn as a biomarker for measuring myocardial injury in these patients and assessing its ability as a prognostic factor for clinical outcome is also discussed.

Pulmonic stenosis is a frequent congenital heart disease in dogs, and the treatment of choice is balloon valvuloplasty which is usually safe and successful. The authors describe for the first time a severe complication after balloon valvuloplasty in a five-month-old dog. After effective treatment, with a considerable drop in right ventricular pressures, the dog developed hypoxemia and dyspnea due to pulmonary edema. The dog underwent intensive care and symptoms improved after a few hours of oxygen therapy, continuous positive airway pressure, and furosemide. Although this event is rare, it could have a large impact on patient survival and should be considered in the treatment of severe pulmonary valve stenosis in the future.

Opioids are widely prescribed for pain management, and it is estimated that 40% of adults in the United States use prescription opioids every year. Opioid misuse leads to high mortality, with respiratory depression as the main cause of death. Animal and human studies indicate that opioid use may lead to sleep-disordered breathing. Opioids affect control of breathing and impair upper airway function, causing central apneas, upper airway obstruction, and hypoxemia during sleep. The presence of obstructive sleep apnea (OSA) increases the risk of opioid-induced respiratory depression. However, even if the relationship between opioids and central sleep apnea is firmly established, the question of whether opioids can aggravate OSA remains unanswered. While several reports have shown a high prevalence of OSA and nocturnal hypoxemia in patients receiving a high dose of opioids, other studies did not find a correlation between opioid use and obstructive events. These differences can be attributed to considerable interindividual variability, divergent effects of opioids on different phenotypic traits of OSA, and wide-ranging methodology. This review will discuss mechanistic insights into the effects of opioids on the upper airway and hypoglossal motor activity and the association of opioid use and obstructive sleep apnea. CITATION: Freire C, Sennes LU, Polotsky VY. Opioids and obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):647–652.

Pulmonary arterial hypertension related to congenital heart disease (PAH-CHD) affects 5% to 10% of adults with CHD and is associated with significant morbidity and mortality. PAH-CHD develops as a consequence of intracardiac or extracardiac systemic-to-pulmonary shunts that lead to pulmonary vascular remodeling through a pathologic process that is similar to other causes of PAH. Eisenmenger syndrome is the most severe phenotype of PAH-CHD and is characterized by severe elevation in pulmonary vascular resistance, with shunt reversal causing hypoxemia and central cyanosis. The primary management strategy for most patients with PAH-CHD is medical therapy, although defect closure is considered in select cases.

Objectives Tracheal intubation in the intensive care unit (ICU) is associated with serious complications. Adherence to the intubation bundle may reduce these complications. We aimed to determine complication rates and whether bundle compliance affected complications. Methods and material We analysed complications of intubation in our ICU. The intubation bundle, with ten elements, is divided into pre-intubation, intubation, and post-intubation. We recorded the complications and classified them as major and minor. Bundle compliance was defined as either full or partial. Chi-square test, Fisher exact test, and student t-test were used and p Results Of 158 adult intubations, 62 intubations were fully compliant with intubation bundle. Complications were similar whether compliance was complete or partial. Serious complications like hypoxemia, cardiovascular collapse, and cardiac arrest occurred during intubation. The need for vasopressor initiation before intubation was associated with severe hypotension, total, and major complications. Higher number of minor complications occurred with more attempts at intubation. Conclusions In our study compliance with intubation bundle did not affect the complications. Tracheal intubations were associated with frequent complications. Vasopressor need before intubation was associated with total and major complications.

Background. Analgesia adequacy in severe blunt thoracic trauma (BTT) is provided by regional anesthesia techniques, one of which is thoracic paravertebral block (TPVB) with proved effectiveness. However, there is no stu­dies of TPVB influence on heart traumatic injuries after BTT. The purpose of the study was to identify TPVB impact in the acute period of BTT, on primary and secondary traumatic injuries of the heart. Materials and methods. The controlled, prospective, non-randomized study is based on the analysis of treatment of 82 patients with BTT: 70 (85.4 %) men and 12 (14.6 %) women, aged 53 years old. Criteria for inclusion were following: blust chest injury with fractures of ribs on one or both sides, offset or no offset debris, the concussion development or non-fatal heart injury. Exclusion criteria: fatal injuries, heart attack, the severity of injuries over 27 scores by the ISS, the very severe condition of the patient, brain contusion II–III degree, acute respiratory failure, artificial lung ventilation. The groups were formed according to BTT severity; in subgroups (a, b) the effectiveness of systemic analgesia (NSAIDs and opioid) and TPVB conducted in the acute period of injury, and within 4–5 days was compared. Group 1: ISS (injury severity score) 16.0 ± 4.4 scores, APACHE II 11.7 ± 3.6; group 2: ISS 17.1 ± 3.9 scores, APACHE II 13.8 ± 4.1; group 3: ISS 18.5 ± 4.9 scores, APACHE II 14.5 ± 2.3. Results. BTT (ISS 18 [14, 20] scores) with lung contusion I and II degree in 62 (76 %) patients (in 22 % patients it was detected on the 1st day, in 79 % — in 2–3 days) was complicated with brain commotion or heart contusion in 70 % of cases, post-traumatic myocardial dystrophy in early and recovery period, almost in all patients. All the patients were admitted in intensive care unit in a state of shock: compensated in patients of group 1 and the maximum decompensated in groups 2 and 3. Systolic blood pressure in group 1 was 143 ± 22 (100 ¸ 180) mmHg, in group 2 — 132 ± 29 (80 ¸ 160), in group 3 125 ± 21 (70 ¸ 150). All the patients had damaged musculoskeletal frame of chest and thoracic organs with early complications: 56 (68 %) had small or mode­rate hemopneumothorax, 16 (32 %) patients closed pneumothorax. All of them underwent urgent closed drainage of pleural cavity. In each subgroup there was only one patient with fractures of the sternum — totally 5 (6.1 %) patients, 3 patients without displacement of fragments, and 2 patients had inconsiderable displacement. The ECG indices were the following: subendocardial and subepicardial changes, tachycardia, extrasystoles, non-specific changes in the final part of ventricular complex, signs of myocardial infarction, traumatic nature, as well as type II, due to bleeding (2 patients). There were no differences between the ECG signs of hemodynamically stable and unstable patients. The use of NSAIDs and opioids (n = 43; the subgroup «a») did not sufficiently reduced pain (Visual Analog Scale (VАS) on the 2nd day — 8 [7, 8] points, on the 3rd day VАS was 7 [6, 7]) and hypo­xemia PaO2/FiO2 295 ± 27 (p = 0.38,), blood oxygen saturation (SрО2) 90.1 ± 1.8 % (р = 0.12), remained peripheral vasospasm (PR 1987 ± 159 din/s · cm2), tachycardia (86 ± 13 · min–1), cardiac reduction (CI 2.71 ± 0.27 l/m2 · min). TPVB performed (n = 39, subgroup “b”) immediately reduced pain by 68 ± 7 %, contributing to better SpO2 (95.6 ± 1.7 vs. 94.1 ± 1.5 %), PaO2/FіO2 340 ± 25 vs. 312 ± 50 in “a” subgroup, decreased tachycardia (80 ± 7 · min–1) and vascular resistance (PR 1692 ± 157 din/s · cm2; p = 0.01), while the favorable increase in cardiac activity (CI 3.10 ± 0.17 l/m2 · min). On the 5th day against TPVB PaO2/FiO2 was greater than in “a” subgroups: 380 ± 28 % vs. 362 ± 27 %; SpO2 96.8 ± 0.7 vs. 95.1 ± 1.1 % (p = 0.02). The manifestations of post-traumatic myocardial dystrophy was observed for 14 days. The ECG re­gistered non-specific ST changes in the form of a slight depression, smoothing of T wave, sometimes spread of P wave, single beats, which did not require additional treatment. TPVB demonstrated evident cardioprotective properties to improve the clinical course of primary and secondary traumatic injuries of the heart. Conclusions. TPVB carried out immediately in the acute period of BTT, due to the pain and hypoxemia reduction has cardioprotective effect, which manifests by in anti-ischemic and anti-arrhythmic effect; allows avoid the complicated concussion and heart contusion, reduces the symptoms of primary and secondary myocardial dystrophy.

Респіраторний дистрес-синдром у дітей — одна з найскладніших патологій, з якою доводиться стикатися у відділеннях реанімації та інтенсивної терапії. У педіатричній практиці були відсутні конкретні рекомендації щодо діагностики та лікування дітей різних вікових груп. Не було конкретних педіатричних дефініцій для респіраторного дистрес-синдрому дорослих. У 2015 році експертами Погоджувальної конференції з педіатричного гострого респіраторного дистрес-синдрому (ПГРДС) (The Pediatric Acute Lung Injury Consensus Conference) були опубліковані конкретні визначення по ГРДС у дітей, а також подані пріоритетні напрямки для майбутніх досліджень. Було розроблено в цілому 151 рекомендацію, що стосуються розділів, пов’язаних із педіатричним гострим респіраторним дистрес-синдромом: визначення, поширеність та епідеміологія; патофізіологія, супутні захворювання та тяжкість; респіраторна підтримка; легенева, допоміжна і нелегенева терапія; моніторинг; неінвазивна респіраторна підтримка та вентиляція; екстракорпоральні методи лікування; захворюваність і довгострокові результати. У цій статті надані основні розроблені рекомендації та конкретизований ряд позицій, що мають особливості тільки для педіатричного ГРДС. До того ж, визначено ряд відмінностей між гострим респіраторним дистрес-синдромом дорослих та дітей як в його діагностиці, так і в лікуванні. При оцінці оксигенації, рівня гіпоксемії та визначенні тяжкості педіатричного ГРДС були прийняті такі показники, як індекс осксигенації (OI) = (FIO2 × середній тиск в дихальних шляхах (Paw) × 100) / РаО2, та індекс насичення киснем (OSI) = (FIO2 × Paw × 100) / SpO2 [11, 12]. Все це буде оптимізувати та покращувати терапію ГРДС у дітей і в подальшому знижувати показник їх смертності від цієї патології.

Acute respiratory failure (ARF) is a syndrome, characterized by inability of the respiratory system to support effective and continuous gas exchange — oxygenation of blood and elimination of carbon dioxide to the environment. ARF is a medical emergency, potentially complicating most respiratory pathologies. The syndrome is globally widespread with increased mortality rate, high rate of intensive care unit admission and considerable inpatient costs. Most common causes of ARF include acute pneumonia, chronic obstructive lung disease, chronic cardiac insufficiency and acute respiratory distress syndrome. There are two main types of ARF: type I (hypoxemic) respiratory failure (when respiratory system is unable to supply enough oxygen to blood and tissues), and type 2 (hypercapnic) respiratory failure (when carbon dioxide accumulates in the body owing to insufficient alveolar ventilation). Acute hypercapnia usually develops as a consequence of affected central nervous system respiratory drive (e.g. structural lesions of respiratory center, drug toxicities), impaired chest bellows (e.g. myasthenia, thoracic trauma, neuromuscular blocking agents) or airway component (e.g. bronchospasm, chronic obstructive pulmonary disease exacerbation). Purely hypoxemic respiratory failure results from deficient alveolar component, when alveolar flooding (e.g. in pneumonia, acute respiratory distress syndrome, cardiogenic pulmonary edema) or atelectasis prevents oxygen from reaching pulmonary circulation. In severe ARF emergency measures of diagnosis and treatment should be implemented simultaneously in order to prevent progression of respiratory failure and development of further life-threatening complications. The diagnosis of ARF is commonly suspected based on clinical presentations, whereas confirmation of the diagnosis and differentiation between hypoxemic and hypercapnic respiratory failure is based mainly on arterial blood gas analysis and pulse oximetry saturation readings. Conventional anterior-posterior chest radiography and computed tomography scanning are the most commonly utilized imaging methods to detect underlying pulmonary di­seases. General principles of supportive care for ARF patients are similar irrespective of the underlying respiratory patho­logy. These include: 1) airways opening and protection (head tilt and chin lift, jaw thrust, oropharyngeal and nasopharyngeal airways, endotracheal intubation, laryngeal mask airway, eso­phageal-tracheal airway, percutaneous cricothyroidotomy, fiber-optic intubation); 2) oxygenation (oxygen supplementation through face mask or nasal cannula when patient is breathing spontaneously, administration of oxygen in gas mixture during mechanical ventilation); and 3) ventilator support (mouth-to-mouth, mouth-to-nose, mouth-to-face mask breathing, bag-valve-mask, mechanical ventilators). Improvement of current medical technologies and principles of respiratory support may result in overall trend of decrease in morbidity and mortality from ARF. However, the probability of favorable outcome in ARF patients also considerably depends on physicians’ ability to recognize the syndrome early and to introduce appropriate measures to support and restore respiratory system function. Based on present-day medical knowledge in the field of emergency and critical care, the article delineates main aspects of ARF pathogenesis, diagnosis and treatment. In particular, the paper describes key pathophysiologic principles of ARF deve­lopment depending on the type of respiratory system structural component involved in the pathologic process, criterions of ARF diagnosis and main principles of supportive care, inclu­ding measures of airway opening and modern methods (modes) of ventilatory support.

У статті описано основні принципи діагностики гострої дихальної недостатності у пацієнтів із сепсисом. Мета. Вивчення даних літератури про сучасні стратегії діагностики гострої дихальної недостатності у дітей із сепсисом і дослідження зміни роботи дихальної та серцево-судинної систем дітей із сепсисом. Матеріали та методи. Проведено проспективне обсерваційне дослідження, до якого було включено 62 пацієнти віком від 12 до 16 років із хірургічним сепсисом. Результати. Проаналізовано дані щодо застосування у дітей Берлінських дефініцій діагностики гострого респіраторного дистрес-синдрому (ГРДС) та спрощених критеріїв для ресурс-лімітованих країн. У дослідженні виявлено, що 54,8 % пацієнтів із сепсисом не потребували проведення респіраторної терапії; 29 % потребували оксигенотерапії, 9,7 % — механічної вентиляції легень (МВЛ). Лише у 55 % пацієнтів, які потребували проведення оксигенотерапії, було тахіпное. Крім того, оцінено показники гемодинаміки (технологія esCCO), встановлено, що у групі пацієнтів, які отримували оксигенотерапію, хвилинний об’єм кровообігу був вищим щодо показників дітей без дихальної недостатності та становив 5,90 ± 0,61 л/хв і 4,80 ± 0,31 л/хв відповідно. Виявлено, що серед дітей, яким проводилася МВЛ, у 50 % була артеріальна гіпотензія при надходженні на лікування, а в подальшому домінували ознаки гіпердинамічного типу кровообігу з підвищеними показниками хвилинного об’єму кровообігу та серцевого індексу, що становили відповідно 6,30 ± 0,42 л/хв і 5,60 ± 0,51 л/хв/м2. Але і надалі зниженим залишався ударний об’єм крові — 41,2 ± 6,1 мл (порівняно з 48,1 ± 3,9 мл у пацієнтів без дихальної недостатності). У пацієнтів, яким проводилася МВЛ, індекс SpO2/FiO2 був вірогідно нижчим порівняно з групою пацієнтів, які отримували оксигенотерапію, і становив відповідно 212,4 ± 10,1 і 232,1 ± 41,5. Індекс PaO2/FiO2 в групі пацієнтів із МВЛ відповідав середньому ступеню гіпоксемії, згідно з Берлінськими дефініціями ГРДС, і становив 200,8 ± 16,4. За результатами аналізу крові на кислотно-лужну рівновагу встановлено, що у хворих групи проведення МВЛ до моменту її початку був декомпенсований змішаний ацидоз із превалюванням метаболічного компоненту. Висновки. Наростання ознак змішаного ацидозу, а також гіпердинамічний тип кровообігу у пацієнтів із сепсисом можуть допомогти верифікувати тих із них, які мають високий ризик розвитку ГРДС., В статье описаны основные принципы диагностики острой дыхательной недостаточности у пациентов с сепсисом. Цель. Изучение данных литературы о современных стратегиях диагностики острой дыхательной недостаточности у детей с сепсисом и исследование изменений работы дыхательной и сердечно-сосудистой систем у детей с сепсисом. Материалы и методы. Проведено проспективное обсервационное исследование, в которое были включены 62 пациента в возрасте от 12 до 16 лет с хирургическим сепсисом. Результаты. Проанализированы данные по использованию у детей Берлинских дефиниций диагностики острого респираторного дистресс-синдрома (ОРДС) и упрощенных критериев для ресурс-лимитированных стран. В исследовании выявлено, что 54,8 % пациентов с сепсисом не нуждались в проведении респираторной поддержки; 29 % нуждались в оксигенотерапии, 9,7 % — в механической вентиляции легких (МВЛ). Только у 55 % пациентов, получающих оксигенотерапию, было тахипноэ. Кроме того, оценены показатели гемодинамики (технология esCCO), установлено, что в группе пациентов, получавших оксигенотерапию, минутный объем кровообращения был выше, чем показатели у детей без дыхательной недостаточности, и составил 5,90 ± 0,61 л/мин и 4,80 ± 0,31 л/мин соответственно. Выявлено, что среди детей, которым проводилась МВЛ, у 50 % была артериальная гипотензия при поступлении на лечение, а в дальнейшем доминировали признаки гипердинамического типа кровообращения с повышенными показателями минутного объема кровообращения и сердечного индекса, которые составляли соответственно 6,30 ± 0, 42 л/мин и 5,60 ± 0,51 л/мин/м2. Но и в дальнейшем пониженным оставался ударный объем крови — 41,2 ± 6,1 мл (по сравнению с 48,1 ± 3,9 мл у пациентов без дыхательной недостаточности). У пациентов, которым проводилась МВЛ, индекс SpO2/FiO2 был достоверно ниже по сравнению с группой пациентов, получавших оксигенотерапию, и составлял соответственно 212,4 ± 10,1 и 232,1 ± 41,5. Индекс PaO2/FiO2 у пациентов группы проведения МВЛ отвечал средней степени гипоксемии, согласно Берлинским дефинициям, и составлял 200,8 ± 16,4. По результатам анализа крови на кислотно-щелочное равновесие установлено, что у больных группы проведения МВЛ до момента ее начала был декомпенсированный смешанный ацидоз с преобладанием метаболического компонента. Выводы. Нарастание признаков смешанного ацидоза, а также гипердинамический тип кровообращения у пациентов с сепсисом могут помочь верифицировать тех из них, которые имеют высокий риск развития ОРДС., Background. In this article, we have described the basic principles of the diagnosis of acute respiratory failure in children with sepsis. The aim of the study was to examine the literature data about current diagnostic strategy of acute respiratory failure in children and to explore the changes of the respiratory and cardiovascular systems in children with sepsis. Materials and methods. This was an open, prospective, observational, non-randomized study of 12–16-year old children with surgical sepsis in the intensive care units. Results. We analyzed data on the use in children of Berlin definitions of acute respiratory distress syndrome and simplified criteria for resource-limited countries. Of 62 patients admitted to the intensive care unit with sepsis, 32 (54.8 %) did not need the respiratory therapy, 32 (29 %) required oxygen therapy, 6 (9.7 %) — mechanical ventilation. Only 55 % of children, who received oxygen therapy, had tachypnea. Furthermore, we assessed hemodynamic parameters (using esCCO technology, Nihon Kohden) and found that patients receiving oxygen therapy had higher cardiac output (5.90 ± 0.61 l/min) than children without respiratory failure (4.80 ± 0.31 l/min). In addition, we found that 50 % of children, who needed mechanical ventilation, had hypotension on admission and signs of hyperdynamic type of circulation with elevation of cardiac output and cardiac index to 6.30 ± 0.42 l/min and 5.60 ± 0.51 l/min/m2, respectively, but low stroke volume — 41.2 ± 6.1 ml compared to 48.1 ± 3.9 ml in patients without respiratory failure. Also, children, who required mechanical ventilation, had significantly lower SpO2/FiO2 index compared to the group of persons receiving oxygen therapy (212.4 ± 10.1 compare to 232.1 ± 41.5). Index PaO2/FiO2 in patients needed mechanical ventilation suggested mild hypoxemia according to Berlin definitions of acute respiratory distress syndrome and was 200.8 ± 16.4. Patients, who required mechanical ventilation, had decompensated mixed acidosis with the prevalence of its metabolic component. Conclusions. Such signs, as mixed decompensated acidosis and hyperdynamic type of the blood circulation, in patients with sepsis may help to verify those of them, who have a higher risk of developing acute respiratory distress syndrome.

We are reporting a fatal case of air embolism. Although minor cases of air embolism may go unnoticed, this is a case of fatal air embolism after intravenous entry of air, which presented with sudden onset of pulseless electrical activity during a computed tomography scan in the radiology department, requiring cardiopulmonary resuscitation for 15 min. Subsequently, after admission to the intensive care unit, we achieved return of spontaneous circulation. The patient was intubated and ventilated in a shock state. He remained in refractory shock despite of supportive care. Cardiaс arrest was registered again in the catheterization lab and the patient could not be revived after 4 h from the initial cardiac arrest. А computed tomography scan was reported to reveal a significant amount of intra-cardiac air, which was the likely cause patient’s death. The case is a rare condition, which highlights the importance of early diagnosis and delivers a message to the medical staff to have a high index of suspicion in patients who have risk factors, and who develop sudden shock with hypoxemia, in order to treat this potentially life-threatening condition effectively in a timely manner., У статті повідомляється про смертельний випадок повітряної емболії. Незважаючи на те що легкі випадки повітряної емболії можуть залишитися непоміченими, це випадок летальної повітряної емболії після внутрішньовенного потрапляння повітря, яка проявилася раптовим початком безімпульсної електричної активності під час комп’ютерної томографії в рентгенологічному відділенні, що вимагало серцево-легеневої реанімації протягом 15 хв. Після повернення спонтанного кровообігу пацієнт був госпіталізований до реанімаційного відділення. Його інтубували та перевели на штучну вентиляцію легенів у шоковому стані. Пацієнт залишався в рефрактерному шоці, незважаючи на підтримуючу терапію. У лабораторії катетеризації знову зареєстровано зупинку серця, і хворого не вдалося реанімувати через 4 год від початкової зупинки серця. Стало відомо, що під час комп’ютерної томографії виявлено значну кількість внутрішньосерцевого повітря, що було ймовірною причиною смерті пацієнта. Цей випадок описує рідкісний стан, що підкреслює важливість ранньої діагностики та нагадує медичному персоналу про необхідність високої настороженості в пацієнтів, які мають фактори ризику та в яких розвивається раптовий шок із гіпоксемією, для вчасного ефективного лікування цього стану, що потенційно загрожує життю.

Background: The effectiveness and side effects of dexmedetomidine (DEX) in combination with midazolam and propofol have not been comparatively studied in a single clinical trial as sedative agents to general anesthesia before. Objective: The objective of this study is to compare intra and post-operative sedation between DEX-Midazolam and DEX-Propofol in patients who underwent major abdominal surgery on the duration of general anesthesia, hemodynamic and sedation effect. Method: This prospective, randomized, double-blinded clinical trial included 50 patients who were 20 to 60 years of age and admitted for major abdominal surgery. The patients were randomly assigned by a computer-generated random numbers table to sedation with DEX plus midazolam (DM group) (n=25) or DEX plus propofol (DP group) (n=25). In the DM group, patients received a bolus dose of 0.1 mg/kg of midazolam and immediately initiated the intravenous (i.v.) infusion of DEX 1 μg/kg over a 10 min and 0.5 μg/kg/hr by continuous i.v. infusion within operation period. In the DP group, patients received pre-anesthetic i.v. DEX 1 μg/kg over 15 min before anesthesia induction and 0.2-1 μg/kg/hr by continuous i.v. infusion during the operative period. After preoxygenation for at least 2 min, during the surgery, patients received propofol infusion dose of 250 μg/kg/min for 15 min then a basal infusion dose of 50 μg/kg/min. The bispectral index (BIS) value, as well as mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), oxygen saturation (SaO2), percutaneous arterial oxygen saturation (SpO2) and end-tidal carbon dioxide tension (ETCO2) were recorded before anesthesia (T0), during anesthesia (at 15-min intervals throughout the surgical procedure), by a blinded observer. Evidence of apnea, hypotension, hypertension and hypoxemia were recorded during surgery. Results: The hemodynamic changes, including HR, MAP, BIS, VT, SaO2, and RR had a downward tendency with time, but no significant difference was observed between the groups (P>0.05). However, the two groups showed no significant differences in ETCO2 and SPO2 values in any of the assessed interval (P>0.05). In this study, the two groups showed no significant differences in the incidence of nausea, vomiting, coughing, apnea, hypotension, hypertension, bradycardia and hypoxemia (P>0.05). Respiratory depression and serious adverse events were not reported in either group. Extubation time after surgery was respectively 6.3 ± 1.7 and 5.8 ± 1.4 hr. in the DM and DP groups and the difference was not statistically significant (P= 0.46). Conclusion: Our study showed no significant differences between the groups in hemodynamic and respiratory changes in each of the time intervals. There were also no significant differences between the two groups in the incidence of complication intra and post-operative. Further investigations are required to specify the optimum doses of using drugs which provide safety in cardiovascular and respiratory system without adverse disturbance during surgery. Clinical Trial Registration Number: HTCY-MA2018-74.

Mechanisms underlying the SARS-CoV-2-triggered hyperacute thrombo-inflammatory response that causes multi-organ damage in coronavirus disease 2019 (COVID-19) are poorly understood. Several lines of evidence implicate overactivation of complement. To delineate the involvement of complement in COVID-19, we prospectively studied 25 ICU-hospitalized patients for up to 21 days. Complement biomarkers in patient sera and healthy controls were quantified by enzyme-linked immunosorbent assays. Correlations with respiratory function and mortality were analyzed. Activation of complement via the classical/lectin pathways was variably increased. Strikingly, all patients had increased activation of the alternative pathway (AP) with elevated levels of activation fragments, Ba and Bb. This was associated with a reduction of the AP negative regulator, factor (F) H. Correspondingly, terminal pathway biomarkers of complement activation, C5a and sC5b-9, were significantly elevated in all COVID-19 patient sera. C5a and AP constituents Ba and Bb, were significantly associated with hypoxemia. Ba and FD at the time of ICU admission were strong independent predictors of mortality in the following 30 days. Levels of all complement activation markers were sustained throughout the patients’ ICU stays, contrasting with the varying serum levels of IL-6, C-reactive protein, and ferritin. Severely ill COVID-19 patients have increased and persistent activation of complement, mediated strongly via the AP. Complement activation biomarkers may be valuable measures of severity of lung disease and the risk of mortality. Large-scale studies will reveal the relevance of these findings to thrombo-inflammation in acute and post-acute COVID-19. Supplementary Information The online version contains supplementary material available at 10.1007/s00430-021-00725-2.

Background Many patients with Coronavirus disease-2019 (Covid-19) present with radiological evidence of pneumonia. Because it is difficult to determine co-existence of bacterial pneumonia, many of these patients are initially treated with antibiotics. We compared the rates of bacterial infections and mortality in Covid-19 patients with pulmonary infiltrates versus patients diagnosed with ‘pneumonia’ the year previously. Methods We conducted a medical record review of patients admitted with Covid-19 and a pulmonary infiltrate and compared them with patients diagnosed with pneumonia admitted in the prior year before the pandemic. Data abstracted included baseline demographics, comorbidities, signs and symptoms, laboratory and microbiological results, and imaging findings. Outcomes were bacterial infections and mortality. Patients presenting with and without Covid-19 were compared using univariable and multivariable analyses. Results There were 1398 and 1001 patients admitted through the emergency department (ED) with and without Covid-19 respectively. Compared with non-Covid-19 patients, those with Covid-19 were younger (61±18 vs. 65±25 years, P

Pulmonary arteriovenous fistulae (PAFs) occur congenitally or are acquired. A PAF can cause hypoxemia, sudden death from rupture, abscess formation, and embolism. Treatment for PAF is transcatheter embolization or surgery. Transcatheter embolization is the first choice of treatment; however, this treatment is impossible to perform if a patient has had tricuspid or pulmonary valve replacement. In this paper, we describe a case of PAFs complicated with tricuspid valve replacement with a ball valve (which had been performed 40 years earlier) that was treated with transcatheter embolization.

Background It is uncertain whether awake prone positioning can prevent intubation for invasive ventilation in spontaneous breathing critically ill patients with acute hypoxemic respiratory failure. Awake prone positioning could benefit these patients for various reasons, including a reduction in direct harm to lung tissue, and prevention of tracheal intubation-related complications. Design and methods The PRONELIFE study is an investigator-initiated, international, multicenter, randomized clinical trial in patients who may need invasive ventilation because of acute hypoxemic respiratory failure. Consecutive patients admitted to participating ICUs are randomly assigned to standard care with awake prone positioning, versus standard care without awake prone positioning. The primary endpoint is a composite of tracheal intubation and all-cause mortality in the first 14 days after enrolment. Secondary endpoints include time to tracheal intubation and effects of awake prone positioning on oxygenation parameters, dyspnea sensation, and complications. Other endpoints are the number of days free from ventilation and alive at 28 days, total duration of use of noninvasive respiratory support, total duration of invasive ventilation, length of stay in ICU and hospital, and mortality in ICU and hospital, and at 28, 60, and 90 days. We will also collect data regarding the tolerance of prone positioning. Discussion The PRONELIFE study is among the first randomized clinical trials investigating the effect of awake prone positioning on intubation rate in ICU patients with acute hypoxemic failure from any cause. The PRONELIFE study is sufficiently sized to determine the effect of awake prone positioning on intubation for invasive ventilation—patients are eligible in case of acute hypoxemic respiratory failure without restrictions regarding etiology. The PRONELIFE study is a pragmatic trial in which blinding is impossible—however, as around 35 ICUs worldwide will participate in this study, its findings will be highly generalizable. The findings of the PRONELIFE study have the potential to change clinical management of patients who may need invasive ventilation because of acute hypoxemic respiratory failure. Trial registration ISRCTN ISRCTN11536318. Registered on 17 September 2021. The PRONELIFE study is registered at clinicaltrials.gov with reference number NCT04142736 (October, 2019).

Background/Aims: Hypoxemia in chronic obstructive pulmonary disease (COPD) leads to reduced ability to exercise, decreased quality of life, and, eventually, increased mortality. Home oxygen therapy in patients with severe COPD reduces distress symptoms and mortality rates. However, there have been few studies on physicians’ prescription behavior toward home oxygen therapy. Therefore, we investigated the respiratory specialists’ perspective on home oxygen therapy.Methods: In this cross-sectional, study, a questionnaire was completed by 30 pulmonary specialists who worked in tertiary hospitals and prescribed home oxygen therapy. The questionnaire consisted of 28 items, including 15 items on oxygen prescription for outpatients, four for inpatients, and nine on service improvement.Results: All physicians were prescribing less than 2 L/min of oxygen for either 24 (n = 10, 33.3%) or 15 hours (n = 9, 30.3%). All (n = 30) used pulse oximetry, 26 (86.7%) analyzed arterial blood gas. Thirteen physicians had imposed restrictions and recommended oxygen use only during exercise or sleep. Sixteen (53.3%) physicians were educating their patients about home oxygen therapy. Furthermore, physicians prescribed home oxygen to patients that did not fit the typical criteria for longterm oxygen therapy, with 30 prescribing it for acute relief and 17 for patients with borderline hypoxemia.Conclusions: This study identified the prescription pattern of home oxygen therapy in Korea. Respiratory physicians prescribe home oxygen therapy to hypoxemic COPD patients for at least 15 hours/day, and at a rate of less than 2 L/min. More research is needed to provide evidence for establishing policies on oxygen therapy in COPD patients.

STUDY OBJECTIVES: Although cognitive impairment in obstructive sleep apnea (OSA) is primarily attributed to intermittent hypoxemia and sleep fragmentation, hypercapnia may also play a role in patients whose OSA is complicated by hypoventilation. This study investigated the impact of hypercapnia on cognitive function in severe sleep-disordered breathing (OSA accompanied by hypoventilation). METHODS: Patients with severe OSA (apnea-hypopnea index >30 events/h; n = 246) underwent evaluation for accompanying hypoventilation with polysomnography that included continuous transcutaneous carbon dioxide (TcCO(2)) monitoring and awake arterial blood gas analysis. Patients were categorized as having no hypoventilation (n = 84), isolated sleep hypoventilation (n = 40), or awake hypoventilation (n = 122). Global cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA), memory with the Rey Auditory Verbal Learning Test (RAVLT), and processing speed with the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV), Digit Symbol Coding subtest (DSC). RESULTS: Apnea-hypopnea index was similar across groups (P = .15), but the sleep and awake hypoventilation groups had greater nocturnal hypoxemia compared with the no-hypoventilation group (P < .01). Within all groups, mean MoCA scores were < 26, which is the validated threshold to indicate mild cognitive impairment; RAVLT scores were lower than age-matched norms only in the awake-hypoventilation group (P ≤ .01); and DSC scores were lower than age-matched norms within all groups (P < .01). In multivariable regression analyses, higher arterial partial pressure of carbon dioxide (PaCO(2)) and TcCO(2) during wakefulness were associated with lower MoCA and DSC scores (P ≤ .03), independent of confounders including overlap syndrome (OSA + chronic obstructive pulmonary disease). CONCLUSIONS: Awake hypoventilation is associated with greater deficits in cognitive function in patients with severe sleep-disordered breathing. CITATION: Beaudin AE, Raneri JK, Ayas NT, Skomro RP, Smith EE, Hanly PJ; on behalf of Canadian Sleep and Circadian Network. Contribution of hypercapnia to cognitive impairment in severe sleep-disordered breathing. J Clin Sleep Med. 2022;18(1):245–254.

Background In patients receiving single lung transplantation for idiopathic pulmonary fibrosis, worsening of fibrosis of the native lung is usually progressive over time, with no significant effects on gas exchange. Case presentation Here, we describe the cases of two Caucasian male recipients of single lung transplants for idiopathic pulmonary fibrosis, 65 and 62 years of age, who exhibited acute worsening of lung fibrosis after an episode of serious viral infection (cytomegalovirus primo-infection in one case and COVID-19 in the other). In both cases, along with opacification of the native lung over several days, the patients presented acute respiratory failure that required the use of high-flow nasal oxygen therapy. Eventually, hypoxemic respiratory failure resolved, but with rapid progression of fibrosis of the native lung. Conclusion We conclude that acute worsening of fibrosis on the native lung secondary to a severe viral infection should be added to the list of potential complications developing on the native lung after single lung transplantation for idiopathic pulmonary fibrosis.

Patients with chronic obstructive pulmonary disease (COPD) may be susceptible to impairments in postural control (PC) when exposed to hypoxia at high altitude. This randomized, placebo-controlled, double-blind, parallel-design trial evaluated the effect of preventive acetazolamide treatment on PC in lowlanders with COPD traveling to 3100 m. 127 lowlanders (85 men, 42 women) with moderate to severe COPD, aged 57 ± 8 y, living below 800 m, were randomized to treatment with acetazolamide 375 mg/d starting 24 h before ascent from 760 m to 3100 m and during a 2-day sojourn in a clinic at 3100 m. PC was evaluated at both altitudes with a balance platform on which patients were standing during five tests of 30 s each. The primary outcome was the center of pressure path length (COPL). In the placebo group, COPL significantly increased from (mean ± SD) 28.8 ± 9.7 cm at 760 m to 30.0 ± 10.0 cm at 3100 m (p = 0.002). In the acetazolamide group, COPL at 760 m and 3100 m were similar with 27.6 ± 9.6 cm and 28.4 ± 9.7 cm (p = 0.069). The mean between-groups difference (acetazolamide-placebo) in altitude-induced change of COPL was −0.54 cm (95%CI −1.66 to 0.58, p = 0.289). Multivariable regression analysis confirmed an increase in COPL of 0.98 cm (0.39 to 1.58, p = 0.001) with ascent from 760 to 3100 m, but no significant effect of acetazolamide (0.66 cm, 95%CI −0.25 to 1.57, p = 0.156) when adjusting for several confounders. In lowlanders with moderate to severe COPD, an ascent to high altitude was associated with impaired postural control and this was not prevented by acetazolamide.

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.

Chronic mountain sickness (CMS) is a clinical syndrome that occurs in natives or long-life residents above 2500 m. It is characterized by excessive erythrocytosis (EE; women hemoglobin (Hb) ≥ 19 g dl −1 ; men Hb ≥ 21 g dl −1 ) and severe hypoxemia which gets worse at bedtime. The etiology of CMS is a decrease of the ventilatory function, which at high altitude produces hypoxemia, the basis of the EE. It exists in a primary form and in a secondary form that is associated with other conditions. The diagnosis of CMS is established primarily through medical review of symptoms and Hb level, which, when excessive, can be treated by bloodletting, medroxyprogesterone (in men), or acetazolamide. The clinical symptoms of CMS gradually disappear after descending to low altitudes and reappear after returning to high altitudes.

Respiratory failure and systemic inflammation are paramount features of severe SARS-CoV-2 disease (COVID-19). Extracorporeal membrane oxygenation (ECMO) therapy has a potential role in patients with refractory disease. An inflammatory response due to blood contact with hemofilters, functioning as a synergic inflammatory stimulus, can lead to a hyperinflammatory state, relatable to cytokine release syndromes. After the first patient succumbed to a refractory vasodilatory shock believed to be due to hyperinflammatory state, a strategy of blood purification through cytokine adsorption therapy (CAT) with CytoSorb® was designed. In this case series, the authors describe the initial experience with such strategy. CAT was employed with no direct complications and helped controlling the inflammatory state, with all patients halting vasopressor support in 72 h and biomarker levels (C-reactive protein, ferritin, and interleukin-6) showing negative trends in most patients. Analysis of inflammatory biomarkers evolution highlighted 2 biomarker profiles related to the presence or absence of superinfection at the time of CAT implementation. In this case series of severe COVID-19 patients, 3 patients died – irreversible lung fibrosis, complications of critical hypoxemia before ECMO induction and complications of systemic anticoagulation were the causes. This case series aimed to contribute to the body of evidence substantiating CAT utilization in hyperinflammatory patients, namely, COVID-19 patients requiring ECMO rescue.

Low tidal volume ventilation protects the lung in mechanically ventilated patients. The impact of the accompanying permissive hypoxemia and hypercapnia on endothelial cell recovery from injury is poorly understood. CA (carbonic anhydrase) IX is expressed in pulmonary microvascular endothelial cells (PMVECs), where it contributes to CO(2) and pH homeostasis, bioenergetics, and angiogenesis. We hypothesized that CA IX is important for PMVEC survival and that CA IX expression and release from PMVECs are increased during infection. Although the plasma concentration of CA IX was unchanged in human and rat pneumonia, there was a trend toward increasing CA IX in the bronchoalveolar fluid of mechanically ventilated critically ill patients with pneumonia and a significant increase in CA IX in the lung tissue lysates of pneumonia rats. To investigate the functional implications of the lung CA IX increase, we generated PMVEC cell lines harboring domain-specific CA IX mutations. By using these cells, we found that infection promotes intracellular (IC) expression, release, and MMP (metalloproteinase)-mediated extracellular cleavage of CA IX in PMVECs. IC domain deletion uniquely impaired CA IX membrane localization. Loss of the CA IX IC domain promoted cell death after infection, suggesting that the IC domain has an important role in PMVEC survival. We also found that hypoxia improves survival, whereas hypercapnia reverses the protective effect of hypoxia, during infection. Thus, we report 1) that CA IX increases in the lungs of pneumonia rats and 2) that the CA IX IC domain and hypoxia promote PMVEC survival during infection.

Sepsis is a clinical syndrome resulting from infection followed by inflammation and is one of the significant causes of mortality worldwide. The underlying reason is the host's uncontrolled inflammatory response due to an infection led to multiple organ dysfunction/failure. Neutrophils, an innate immune cell, are forerunners to reach the site of infection/inflammation for clearing the infection and resolute the inflammation during sepsis. A relatively new neutrophil effector function, neutrophil extracellular traps (NETs), have been demonstrated to kill the pathogens by releasing DNA decorated with histone and granular proteins. A growing number of pieces of shreds of evidence suggest that unregulated incidence of NETs have a significant influence on the pathogenesis of sepsis-induced multiple organ damage, including arterial hypotension, hypoxemia, coagulopathy, renal, neurological, and hepatic dysfunction. Thus, excessive production and improper resolution of NETs are of significant therapeutic value in combating sepsis-induced multiple organ failure. The purpose of this review is intended to highlight the role of NETs in sepsis-induced organ failure. Furthermore, the current status of therapeutic strategies to intersect the harmful effects of NETs to restore organ functions is discussed.

A man affected by hereditary hemorrhagic telangiectasia who had chronic severe hypoxemia is presented. This hypoxemia was synergistically caused by high-output heart failure due to severe hepatic shunts and multiple pulmonary arteriovenous shunts. The symptomatic combination is rare, and genetic testing showed a novel endoglin mutation. (Level of Difficulty: Advanced.), Central Illustration

Human lives and nations’ economies have been adversely affected worldwide by the COVID-19 pandemic. The hyperinflammatory state associated with the disease may be related to mortality. Systemic glucocorticoid is the first-line therapy for cytokine storm. Various immunomodulatory drugs such as tocilizumab and baricitinib have been used in those not responding to glucocorticoid monotherapy. Amid the peak crisis of COVID-19 in India, there was an extreme paucity of medications, oxygen, and hospital beds. We describe three patients with COVID-19 who received low-dose tofacitinib (an oral Janus kinase inhibitor) in addition to moderate-dose glucocorticoid. These patients were treated at their homes, as the hospitals were short of beds. Rapid reduction in hypoxemia along with gradual resolution of other signs of the disease were observed. The results are reassuring regarding the feasibility of managing of severe COVID-19 outside the hospital setting when healthcare resources are overwhelmed by pandemic-related caseload.

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 2 > 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.

Key points Vascular dysfunction has been demonstrated in lowlanders at high-altitude (>4,000 m), however the extent of impairment and the delineation of contributing mechanisms have remained unclear. Using the gold-standard isolated perfused forearm model, we determined the extent of vasodilatory dysfunction and oxidative stress as a contributing mechanism in healthy lowlanders before and 4-6 days after rapid ascent to 4,300 m. The total forearm blood flow response to acetylcholine at high-altitude was decreased by ∼30%. Co-infusion of acetylcholine with the antioxidant vitamin C partially restored the total forearm blood flow by ∼20%. The magnitude of forearm blood flow reduction, as well as the impact of oxidative stress, was positively associated with the individual severity of hypoxemia. These data extend our basic understanding of vascular (mal)adaptation to high-altitude sojourn, with important implications for understanding the etiology of high-altitude related changes in endothelial-mediated vasodilatory function. Abstract High-altitude induced hypoxemia is often associated with peripheral vascular dysfunction; however, the basic mechanism(s) underlying high-altitude vascular impairments remains unclear. This study tested the hypothesis that oxidative stress contributes to the impairments in endothelial function during early acclimatization to high-altitude. Ten young healthy lowlanders were tested at sea-level (344 m) and following 4-6 days at high-altitude (4,300 m). Vascular endothelial function was determined using the isolated perfused forearm technique with forearm blood flow (FBF) measured by strain-gauge venous occlusion plethysmography. FBF was quantified in response to acetylcholine (ACh), sodium nitroprusside (SNP), and co-infusion of ACh with the antioxidant vitamin C (ACh+VitC). The total FBF response to ACh (area under the curve) was ∼30% lower at high-altitude compared to sea-level (P = 0.048). There was no difference in the response to SNP at high-altitude (P = 0.860). At sea-level, co-infusion of ACh+VitC had no influence on the FBF dose response (P = 0.268); however, at high-altitude ACh+VitC resulted in an average increase in the FBF dose response by ∼20% (P = 0.019). At high-altitude, the decreased FBF response to ACh, and the increase in FBF in response to ACh+VitC, were associated with the magnitude of arterial hypoxemia (R2 = 0.60, P = 0.008 and R2 = 0.63, P = 0.006, respectively). Collectively, these data support the hypothesis that impairments in vascular endothelial function at high-altitude are in part attributable to oxidative stress, consequent of the magnitude of hypoxemia. These data extend our basic understanding of vascular (mal)adaptation to high-altitude sojourn, with important implications for understanding the etiology of high-altitude related vascular dysfunction. This article is protected by copyright. All rights reserved.

Hepatopulmonary syndrome (HPS) is characterized by defects in oxygenation caused by intra-pulmonary vasodilation occurring because of chronic liver disease, portal hypertension, or congenital portosystemic shunts. Clinical implications of portal hypertension are very well-known, however, awareness of its effect on multiple organs such as the lungs are less known. The presence of HPS in chronic liver disease is associated with increased mortality. Medical therapies available for HPS have not been proven effective and definitive treatment for HPS is mainly liver transplantation (LT). LT improves mortality for patients with HPS drastically. This article provides a review on the definition, clinical presentation, diagnosis, and management of HPS.

Background: The coronavirus disease 2019 (COVID-19) pandemic is an ongoing global crisis challenging the worldwide healthcare systems. Many patients present with a mismatch of profound hypoxemia and few signs of respiratory distress (i.e., silent hypoxemia). This particular clinical presentation is often cited, but data are limited. Main Body: We describe dyspnea sensation as assessed by using the BORG scale in pulmonary patients admitted to the emergency room during a 4-week period and transferred to the respiratory department of Siloah Hospital, Hannover, Germany. From October 1 to November 1, 2020, 82 patients with hypoxemia defined as oxygen demand to achieve an oxygen saturation (SpO2) ≥92% were included. In 45/82 (55%) patients, SARS-CoV-2 was detected by PCR on admission. Among non-COVID patients, exacerbation of COPD was the main diagnosis (15/37, 41%). All subjects rated their perceived dyspnea using the modified Borg CR10 scale. Patients in the non-COVID group suffered from more dyspnea on the modified Borg CR10 scale (median 1, IQR: 0–2 vs. median 5, IQR: 3–6, p < 0.001). In multivariate analysis, “silent hypoxemia” as defined by the dyspnea Borg CR10 scale ≥5 was independently associated with COVID-19 and presence of severe hypocapnia with an odds ratio of 0.221 (95% confidence interval 0.054, 0.907, p 0.036). Conclusion: Among pulmonary patients with acute hypoxemia defined as oxygen demand, patients suffering from COVID-19 experience less dyspnea compared to non-COVID patients. “Silent” hypoxemia was more common in COVID-19 patients.

With the advent of thoracoscopic surgery, the benefits of lung isolation in children have been increasingly recognized. However, because of the small airway dimensions, equipment limitations in size and maneuverability, and limited respiratory reserve, one-lung ventilation in children remains challenging. This article highlights some of the most common error traps in the management of pediatric lung isolation and focuses on practical solutions for their management. The error traps discussed are as follows: (1) the failure to take into consideration relevant aspects of tracheobronchial anatomy when selecting the size of the lung isolation device, (2) failure to execute correct placement of the device chosen for lung isolation, (3) failure to maintain lung isolation related to surgical manipulation and isolation device movement, (4) failure to select appropriate ventilator strategies during one-lung ventilation, and (5) failure to appropriately manage and treat hypoxemia in the setting of one-lung ventilation.

The coexistence of expiratory central airway collapse and diaphragmatic paralysis presents a diagnostic and treatment challenge. Both entities are underrecognized causes of dyspnea, cough, sputum production, and orthopnea. Optimal treatment must be individualized and is best achieved by a multidisciplinary team. We present a case of a patient with profound functional impairment from dyspnea and hypoxemia due to expiratory central airway collapse, complicated by bronchiectasis from recurrent respiratory infections, and diaphragmatic paralysis.

Introduction Robin sequence (RS) is a leading cause of obstructive sleep apnea (OSA) in newborns. Most studies have focused on understanding anatomic factors leading to OSA and changes in apnea–hypopnea index (AHI) on polysomnography (PSG) beyond the neonatal period. This study aims to define age-related OSA features between patients with RS, without RS and healthy controls using PSG-based analyses of respiratory arousal responses and gas-exchange parameters. Design Retrospective comparison of PSG features in a total of 48 children encompassing three groups: (a) infants with RS (n = 24, Results OSA sleep-stage specific indexes (rapid eye movement [REM] vs non-REM[NREM]) as well as position-specific indexes (supine vs nonsupine) were similar in individuals with and without RS. Relative to the non-RS groups, infants with RS have more sustained hypoxemia (time with SpO2 < 90%) and reduced arousal responses to OSA demonstrated by higher OAHI/respiratory arousal indexes. OAHI/respiratory arousal indexes significantly correlated with the severity of hypoxemia in infants with RS. Conclusion Infants with RS and OSA show reduced arousal responses to apneic events, which correlates with higher hypoxemia severity. OAHI/respiratory arousal indexes in RS may identify high-risk individuals with upper airway obstruction and reduced arousal protective responses.