Severe Hypoxemia Research Articles

Symposium review: high altitude travel with pulmonary vascular disease.

Pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension are the main precapillary forms of pulmonary hypertension (PH) summarized as pulmonary vascular diseases (PVD). PVDs are characterized by exertional dyspnoea and oxygen desaturation, and reduced quality of life and survival. Medical therapies improve life expectancy and physical performance of PVD patients, of whom many wish to participate in professional work and recreational activities including traveling to high altitude. The exposure to the hypobaric hypoxic environment of mountain regions incurs the risk of high altitude adverse events (AEHA) due to severe hypoxaemia exacerbating symptoms and further increase in pulmonary artery pressure, which may lead to right heart decompensation. Recent prospective and randomized trials show that altitude-induced hypoxaemia, pulmonary haemodynamic changes and impairment of exercise performance in PVD patients are in the range found in healthy people. The vast majority of optimally treated stable PVD patients who do not require long-term oxygen therapy at low altitude can tolerate short-term exposure to moderate altitudes up to 2500m. PVD patients that reveal persistent severe resting hypoxaemia ( <80% for >30min) at 2500m respond well to supplemental oxygen therapy. Although there are no accurate predictors for AEHA, PVD patients with unfavourable risk profiles at low altitude, such as higher WHO functional class, lower exercise capacity with more pronounced exercise-induced desaturation and more severely impaired haemodynamics, are at increased risk of AEHA. Therefore, doctors with experience in PVD and high-altitude medicine should counsel PVD patients before any high-altitude sojourn. This review aims to summarize recent literature and clinical recommendations about PVD patients travelling to high altitude.

Intraoperative Hypoxemia in the Right Lateral Decubitus Position: A Case Report

Platypnea-Orthodeoxia syndrome (POS), an exceptionally uncommon condition, is characterized by decreased oxygen saturation in an upright posture with corresponding improvement in the supine position. Recently, an 85-year-old female patient presented for surgery due to a left femoral neck fracture. Following successful tracheal intubation and anesthesia induction, the ventilator indicated an airway pressure of 15mmHg. While in the right lateral decubitus position, the patient developed hypoxia despite normal arterial blood pressure and symmetrical breath sounds. Attempts to alleviate the hypoxia through pure oxygen ventilation, tympanic lung ventilation, and high-frequency ventilation were unsuccessful. Subsequently, there was a notable decrease in both blood pressure and heart rate, prompting an immediate halt to the surgery and repositioning the patient to the supine position. This resulted in the normalization of the patient&amp;apos;s heart rate, oxygen saturation, and blood pressure. To investigate the etiology, a TEE probe was inserted, revealing the presence of a patent foramen ovale (PFO) and a significant right-to-left shunt while the patient was in the lateral position. The procedure was performed in a specific right lateral decubitus position. This case may represent a unique manifestation of POS syndrome, expanding the differential diagnosis for intraoperative position-related hypoxemia. Given the severe hypoxemia observed with intraoperative positional changes, a strong suspicion of POS syndrome is warranted.

Extracorporeal membrane oxygenation versus invasive ventilation in patients with COVID-19 acute respiratory distress syndrome and pneumomediastinum: A cohort trial.

Patients with severe respiratory failure due to COVID-19 who are not under mechanical ventilation may develop severe hypoxemia when complicated with spontaneous pneumomediastinum (PM). These patients may be harmed by invasive ventilation. Alternatively, veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) may be applied. We report on the efficacy of V-V ECMO and invasive ventilation as initial advanced respiratory support in patients with COVID-19 and acute respiratory failure due to spontaneous PM. This was a retrospective cohort study performed between March 2020 and January 2022. Enrolled patients had COVID-19 and acute respiratory failure due to spontaneous PM and were not invasively ventilated. Patients were treated in the intensive care unit (ICU) with invasive ventilation (invasive ventilation group) or V-V ECMO support (V-V ECMO group) as the main therapeutic option. The primary outcomes were mortality and ICU discharge at 90 days after ICU admission. Twenty-two patients were included in this study (invasive ventilation group: 13 [59%]; V-V ECMO group: 9 [41%]). The V-V ECMO strategy was significantly associated with lower mortality (hazard ratio [HR] 0.33 [95% CI 0.12-0.97], p = 0.04). Five (38%) patients in the V-V ECMO group were intubated and eight (89%) patients in the invasive ventilation group required V-V ECMO support within 30 days from ICU admission. Three (33%) patients in the V-V ECMO group were discharged from ICU within 90 days compared to one (8%) patient in the invasive ventilation group (HR 4.71 [95% CI 0.48-45.3], p = 0.18). Preliminary data suggest that V-V ECMO without invasive ventilation may improve survival in COVID-19-related acute respiratory failure due to spontaneous PM. The study's retrospective design and limited sample size underscore the necessity for additional investigation and warrant caution.

Profound hypoxemia and hypotension during posterior spinal fusion in a spinal muscular atrophy child with severe scoliosis: a case report

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

Pulse oximetric saturation/fraction of inspired oxygen and partial pressure of oxygen/fraction of inspired oxygen in diagnosing acute respiratory distress syndrome: which is better?

Acute Respiratory Distress Syndrome (ARDS) is distinguished by hypoxemia, contributing to heightened morbidity, elevated mortality rates, and substantial healthcare expenses, thereby imposing a significant burden on patients and society. Presently, effective treatments for ARDS are lacking, emphasizing the pivotal role of early diagnosis and timely intervention in its successful management. The partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2, P/F) has traditionally served as a crucial metric for assessing patient hypoxemia and disease severity. While relatively accurate, its reliance on advanced technical expertise and specific medical equipment conditions constrains its implementation in areas with underdeveloped medical standards, resulting in missed diagnoses and treatments for ARDS patients. Conversely, the Pulse oximetric saturation/fraction of inspired oxygen (SpO2/FiO2, S/F) has garnered increasing attention owing to its straightforward, non-invasive, and sustainable monitoring attributes. This article seeks to meticulously compare the correlation, accuracy, and clinical feasibility of S/F with P/F in ARDS diagnosis, so as to propose diagnostic indicators for more quickly and accurately assessing the oxygenation status of ARDS patients.

Sleep-disordered breathing and nocturnal hypoxemia in chronic thromboembolic pulmonary disease.

Sleep-disordered breathing (SDB) and nocturnal hypoxemia were known to be present in patients with chronic thromboembolic pulmonary hypertension (CTEPH), but the difference betweenSDB and nocturnal hypoxemia in patients who have chronic thromboembolic pulmonary disease (CTEPD) with or without pulmonary hypertension (PH) at rest remains unknown. Patients who had CTEPH (n = 80) or CTEPD without PH (n= 40) and who had undergone sleep studies from July 2020 to October 2022 at Shanghai Pulmonary Hospital were enrolled. Nocturnal mean SpO2 (Mean SpO2) <90% was defined as nocturnal hypoxemia, and the percentage of time with a saturation below 90% (T90%) exceeding 10% was used to evaluate the severity of nocturnal hypoxemia. Logistic and linear regression analyses were performed to investigate the difference and potential predictor of SDB or nocturnal hypoxemia between CTEPH and CTEPD without PH. SDB was similarly prevalent in CTEPH and CTEPD without PH (P = 0.104), both characterised by obstructive sleep apnoea (OSA). Twenty-two patients with CTEPH were diagnosed with nocturnal hypoxemia, whereas only three were diagnosed with CTEPD without PH (P = 0.021). T90% was positively associated with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance in patients with CTEPH and CTEPD without PH (P < 0.001); T90% was also negatively related to cardiac output in these patients. Single-breath carbon monoxide diffusing capacity, sex and mPAP were all correlated with nocturnal hypoxemia in CTEPH and CTEPD without PH (all P < 0.05). Nocturnal hypoxemia was worse in CTEPD with PH; T90%, but not SDB, was independently correlated with the hemodynamics in CTEPD with or without PH.

Physiologically based modeling reveals different risk of respiratory depression after fentanyl overdose between adults and children.

Despite a rapid increase in pediatric mortality rate from prescription and illicit opioids, there is limited research on the dose-dependent impact of opioids on respiratory depression in children, the leading cause of opioid-associated death. In this article, we extend a previously developed translational model to cover pediatric populations by incorporating age-dependent pharmacokinetic, pharmacodynamic, and physiological changes compared to adults. Our model reproduced previous perioperative clinical findings that adults and children have similar risk of respiratory depression at the same plasma fentanyl concentration when specific endpoints (minute ventilation, CO2 tension in the blood) were used. However, our model points to a potential caveat that, in a perioperative setting, routine use of mechanical ventilation and supplemental oxygen maintained the blood and tissue oxygen partial pressures in patients and prevented the use of oxygen-related endpoints to evaluate the consequences of respiratory depression. In a community setting when such oxygenation procedures are not immediately available, our model suggests that the higher oxygen demand and reduced cerebrovascular reactivity could make children more susceptible to severe hypoxemia and brain hypoxia, even with the same plasma fentanyl concentration as adults. Our work indicates that when developing intervention strategies to protect children from opioid overdose in a community setting, these pediatric-specific factors may need to be considered.

Effectiveness of bubble continuous positive airway pressure for treatment of children aged 1–59 months with severe pneumonia and hypoxaemia in Ethiopia: a pragmatic cluster-randomised controlled trial

The safety and efficacy of bubble continuous positive airway pressure (bCPAP) for treatment of childhood severe pneumonia outside tertiary care hospitals is uncertain. We did a cluster-randomised effectiveness trial of locally made bCPAP compared with WHO-recommended low-flow oxygen therapy in children with severe pneumonia and hypoxaemia in general hospitals in Ethiopia. This open, cluster-randomised trial was done in 12 general (secondary) hospitals in Ethiopia. We randomly assigned six hospitals to bCPAP as first-line respiratory support for children aged 1-59 months who presented with severe pneumonia and hypoxaemia and six hospitals to standard low-flow oxygen therapy. Cluster (hospital) randomisation was stratified by availability of mechanical ventilation. All children received treatment in paediatric wards (in a dedicated corner in front of a nursing station) with a similar level of facilities (equipment for oxygen therapy and medications) and staffing (overall, one nurse per six patients and one general practitioner per 18 patients) in all hospitals. All children received additional care according to WHO guidelines, supervised by paediatricians and general practitioners. The primary outcome was treatment failure (defined as any of the following: peripheral oxygen saturation <85% at any time after at least 1 h of intervention plus signs of respiratory distress; indication for mechanical ventilation; death during hospital stay or within 72 h of leaving hospital against medical advice; or leaving hospital against medical advice during intervention). The analysis included all children enrolled in the trial. We performed both unadjusted and adjusted analyses of the primary outcome, with the latter adjusted for the stratification variable and for the design effect of cluster randomisation, as well as selected potentially confounding variables, including age. We calculated effectiveness as the relative risk (RR) of the outcomes in the bCPAP group versus low-flow oxygen group. This trial is registered with ClinicalTrial.gov, NCT03870243, and is completed. From June 8, 2021, to July 27, 2022, 1240 children were enrolled (620 in hospitals allocated to bCPAP and 620 in hospitals allocated to low-flow oxygen). Cluster sizes ranged from 103 to 104 children. Five (0·8%) of 620 children in the bCPAP group had treatment failure compared with 21 (3·4%) of 620 children in the low-flow oxygen group (unadjusted RR 0·24, 95% CI 0·09-0·63, p=0·0015; adjusted RR 0·24, 0·07-0·87, p=0·030). Six children died during hospital stay, all of whom were in the low-flow oxygen group (p=0·031). No serious adverse events were attributable to bCPAP. In Ethiopian general hospitals, introduction of locally made bCPAP, supervised by general practitioners and paediatricians, was associated with reduced risk of treatment failure and in-hospital mortality in children with severe pneumonia and hypoxaemia compared with use of standard low-flow oxygen therapy. Implementation research is required in higher mortality settings to consolidate our findings. SIDA Sweden and Grand Challenges Ethiopia.

Prone position in severe hypoxemia in patients with covid-19 during venovenous ECMO, does the number of cycles matter?

Extracorporeal membrane oxygenation (ECMO) support has been known to be beneficial in cases of severe Adult Respiratory Distress Syndrome (ARDS). The increase in such cases results in an increase in scenarios of severe hypoxemia even during an ECMO run. The purpose of this study was to evaluate the benefit of the prone position (PP) in an analytical observational retrospective cohort study. The study included adult patients with ARDS, caused as a result of SARS-CoV-2, undergoing PP during ECMO support in the period from 2020 to 2021. Thirty-five patients were placed in PP with an average of 3.6 cycles per patient. The group of patients undergoing &gt;3 PP cycles had a significant improvement in oxygenation during PP, 𝑃𝑎𝑂2 (60.13 vs. 66.15, mmHg p = 0.0065) and 𝑃𝑎𝑂2⁄𝐹𝑖𝑂2 (136 vs. 155, p = 0.0026). After adjusting for confounding variables (age, RESP score, and days from the start of ECMO and the first cycle of PP), the group with &gt;3 cycles showed a hazard ratio of 0.2 (95% confidence interval, 0.051–0.78; p = 0.02). The study outcomes confirmed the benefits of PP as a strategy against severe hypoxemia in ECMO, and evaluated variables such as the number of cycles, which may be associated with improved survival in this subgroup of critically ill patients.

Lower vs Higher Oxygenation Target and Days Alive Without Life Support in COVID-19

Supplemental oxygen is ubiquitously used in patients with COVID-19 and severe hypoxemia, but a lower dose may be beneficial. To assess the effects of targeting a Pao2 of 60 mm Hg vs 90 mm Hg in patients with COVID-19 and severe hypoxemia in the intensive care unit (ICU). Multicenter randomized clinical trial including 726 adults with COVID-19 receiving at least 10 L/min of oxygen or mechanical ventilation in 11 ICUs in Europe from August 2020 to March 2023. The trial was prematurely stopped prior to outcome assessment due to slow enrollment. End of 90-day follow-up was June 1, 2023. Patients were randomized 1:1 to a Pao2 of 60 mm Hg (lower oxygenation group; n = 365) or 90 mm Hg (higher oxygenation group; n = 361) for up to 90 days in the ICU. The primary outcome was the number of days alive without life support (mechanical ventilation, circulatory support, or kidney replacement therapy) at 90 days. Secondary outcomes included mortality, proportion of patients with serious adverse events, and number of days alive and out of hospital, all at 90 days. Of 726 randomized patients, primary outcome data were available for 697 (351 in the lower oxygenation group and 346 in the higher oxygenation group). Median age was 66 years, and 495 patients (68%) were male. At 90 days, the median number of days alive without life support was 80.0 days (IQR, 9.0-89.0 days) in the lower oxygenation group and 72.0 days (IQR, 2.0-88.0 days) in the higher oxygenation group (P = .009 by van Elteren test; supplemental bootstrapped adjusted mean difference, 5.8 days [95% CI, 0.2-11.5 days]; P = .04). Mortality at 90 days was 30.2% in the lower oxygenation group and 34.7% in the higher oxygenation group (risk ratio, 0.86 [98.6% CI, 0.66-1.13]; P = .18). There were no statistically significant differences in proportion of patients with serious adverse events or in number of days alive and out of hospital. In adult ICU patients with COVID-19 and severe hypoxemia, targeting a Pao2 of 60 mm Hg resulted in more days alive without life support in 90 days than targeting a Pao2 of 90 mm Hg. ClinicalTrials.gov Identifier: NCT04425031.

Use of the Serum Level of Cholinesterase as a Prognostic Marker of Nonfatal Clinical Outcomes in Patients Hospitalized with Acute Exacerbations of Chronic Obstructive Pulmonary Disease.

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) contributes to a poor prognosis. Reliable biomarkers to predict adverse outcomes during hospitalization are important. To investigate the relationship between the serum cholinesterase (ChE) level and adverse clinical outcomes, including hypoxemia severity, hypercapnia, duration of hospital stay (DoHS), and noninvasive ventilation (NIV) requirement, in patients with AECOPD. Patients hospitalized with AECOPD in the Wuhu Hospital of Traditional Chinese Medicine between January 2017 and December 2021 were included. A total of 429 patients were enrolled. The serum ChE level was significantly lower in patients with hypercapnia, who required NIV during hospitalization and who had a DoHS of >10 days, with an oxygenation index < 300. The ChE level was correlated negatively with the C-reactive protein level and neutrophil-to-lymphocyte ratio and correlated positively with the serum albumin level. Multivariate logistic regression analysis indicated that a serum ChE level of ≤4116 U/L (OR = 2.857, 95% CI = 1.46-5.58, p = 0.002) was associated significantly with NIV requirement. The serum ChE level was correlated significantly with complicating severe hypoxemia, hypercapnia, prolonged DoHS, and the need for NIV in patients hospitalized with AECOPD. The serum ChE level is a clinically important risk-stratification biomarker in patients hospitalized with AECOPD.

Early Prone Position Ventilation in the Efficacy for Severe Hypoxemia and Neurological Complications Following Acute Type A Aortic Dissection (TAAD) Surgery

Objective To analyze the efficacy of early prone position ventilation in the treatment of severe hypoxemia after surgery for acute type A aortic dissection (TAAD). Methods The patients were divided into a control group and a treatment group. Parameters assessed included blood gas analysis indicators [arterial oxygen partial pressure (PaO2). Results: (1) Blood gas analysis: Before treatment, there was no significant difference in PaO2, SpO2, and OI levels between the two groups; after treatment, the PaO2, SpO2, and OI levels in both groups significantly increased compared to pre-treatment, with a more pronounced improvement in the treatment group than in the control group (p < 0.05). (2) Hemodynamics: Before treatment, there was no significant difference in MAP and HR levels between the two groups; after treatment, the MAP levels increased significantly in both groups compared to pre-treatment, while HR levels decreased significantly, with no significant difference between the groups. (3) Prognosis recovery: MV time, ICU stay, and total hospital stay were significantly lower in the treatment group than in the control group; the 30-day mortality rate was 14.58% in the control group and 12.50% in the treatment group, with no significant difference in 30-day mortality rate between the groups. Conclusion Early prone position ventilation has shown promising application in the treatment of severe hypoxemia after TAAD surgery. Compared to traditional supine position ventilation, the use of early prone position ventilation can further improve blood gas analysis indicators in patients, and shorten MV time, ICU stay, and total hospital stay, thereby accelerating patient recovery.

EFFICACY OF TOLAZOLINE AND VATINOXAN IN REDUCING ADVERSE EFFECTS OF BUTORPHANOL-AZAPERONE-MEDETOMIDINE IMMOBILIZATION IN ROCKY MOUNTAIN ELK (CERVUS CANADENSIS).

A mixture of butorphanol, azaperone, and medetomidine (BAM) is frequently used for immobilization of North American hoofstock. Common adverse effects include respiratory depression, hypoxemia, and bradycardia. In this nonblinded crossover study the efficacy of two a-2 adrenergic antagonists, tolazoline and vatinoxan, were evaluated in alleviating adverse effects of BAM in Rocky Mountain elk (Cervus canadensis). Early administration of these antagonists was hypothesized to cause an increase in heart rate, respiratory rate, partial pressure of oxygen (PaO2) and hemoglobin oxygen saturation (SpO2), as well as reduction in mean arterial blood pressure without affecting sedation levels. Eight captive adult female elk were immobilized on three separate occasions at least 14 d apart with 0.15 mg/kg butorphanol, 0.05 mg/kg azaperone, and 0.06 mg/kg medetomidine. Tolazoline (2 mg/kg IM), vatinoxan (3 mg/mg medetomidine IV) or sterile saline (2 ml IM) were administered 20 min postinduction. The BAM caused hypoxemia, bradycardia, and moderate hypertension, and because of the severe hypoxemia observed, all animals received intratracheal oxygen throughout immobilization. Heart rate, respiratory rate, rectal temperature, SpO2, PaO2, and systolic, diastolic, and mean arterial blood pressure were monitored every 5 min throughout the immobilization. Intramuscular tolazoline caused a brief but significant drop in mean arterial pressure compared with controls and a brief but nonsignificant increase in heart rate. Vatinoxan caused a significant drop in blood pressure and a brief significant increase in heart rate. Changes in respiratory rates and PaO2 were not observed with either antagonist; however, all animals received oxygen, which may have influenced this result. The depth of sedation was unchanged after administration of either drug.

Protocol for venoarterial ExtraCorporeal Membrane Oxygenation to reduce morbidity and mortality following bilateral lung TransPlantation: the ECMOToP randomised controlled trial

IntroductionLung transplantation (LTx) aims at improving survival and quality of life for patients with end-stage lung diseases. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used as intraoperative support for LTx, despite...

Percutaneous Coronary Intervention Associated with a Higher Risk of Hypoxemia and COVID-19 Severity.

The primary goal of the present study was to measure the implications of hypoxemia in COVID-19 patients with a history of coronary artery disease (CAD). A systematic search of the literature published from November 1, 2019 to May 1, 2021, was conducted on PubMed/MEDLINE, Embase, and Web of Science databases. Afterwards, an observational study was designed based on the electronic health records of COVID-19 patients hospitalized in a tertiary referral hospital during the same period. A total of 179 COVID-19 cases were divided into two groups: cases with a history of CAD and percutaneous coronary intervention (CAD/PCI+, n = 89) and controls (n = 90). Clinical data were extracted from the electronic database of the hospital and statistically analyzed. After the application of inclusion/exclusion criteria, only three studies were deemed eligible, one of which was concerned with the impact of CAD on the all-cause mortality of COVID-19. Results from our observational study indicated that the cases were older (median age: 74 vs. 45) and more likely to develop hypoxemia (25.8% vs. 8.8%) than the controls. CAD/PCI+ was correlated with a more severe COVID-19 (11% vs. 1%). Age was a moderately significant independent predictor of increased COVID-19 severity, while hypoxemia was not. Considering the negative impact of hypoxemia on the prognosis of COVID-19 and its higher prevalence among COVID-19 patients with underlying CAD, further research is warranted to unravel the negative effects of COVID-19 on the mechanisms of gas exchange and delivery in patients with pre-existing CAD.

Allergic rhinitis as a predictor of moderate-to-severe paediatric obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is a common sleep-related breathing disorder affecting children. This study aims to characterize factors associated with the development and progression of severe forms of paediatric OSA. This study included children admitted to Children's Hospital of Chongqing Medical University, a tertiary children's hospital in southwest China between January 2020 and December 2020 with a discharge diagnosis of OSA. Each patient underwent polysomnography examination, following assessments of apnoea-hypopnea index (AHI) and lowest oxygen saturation (LSaO2) by standardized techniques. Demographic and clinical information was collected from the hospital's electronic medical records. Associations between OSA severity and various factors were first examined in a univariate logistic model, with subsequent multivariate analysis to further identify independent risk factors. A total of 263 children were identified during the study period. Among patients presenting with OSA, 51.3% had mild and 48.7% had moderate to severe symptoms according to standardized guidelines. The incidence of mild and moderate to severe hypoxemia in our population was 39.2% and 60.8%, respectively. Allergic rhinitis (AR; adjusted odds ratio (aOR) = 1.75, 95% CI 1.03-2.96) and male gender (aOR = 1.77, 95% CI 1.03-3.06) were significantly associated with moderate-to-severe OSA (all P-values < 0.05) after adjustment for covariates. AR was also the only significant predictor of hypoxemia (P < 0.05). Our results suggest that male gender and presence of AR may be associated with an increased likelihood of moderate-to-severe OSA in children. These findings underscore the importance of timely intervention and individualized management for at-risk individuals.

ЗНАЧЕНИЕ ИММУНОЛОГИЧЕСКОГО СКРИНИНГА В ПРОГНОЗИРОВАНИИ ИНФЕКЦИОННЫХ ОСЛОЖНЕНИЙ КАРДИОХИРУРГИИ

Incidence of infectious complications in children with congenital heart disease, especially with cyanotic and complex defects, is higher than in the population, which is associated with both hemodynamic and immune disorders. Various types of primary immunodeficiencies in congenital heart disease and the dependence of immune disorders on the morphology of the defect, the severity of circulatory failure and arterial hypoxemia are described. The importance of diagnosing immunological disorders is emphasized to reduce the risk of infectious complications of cardiac surgery, reduce mortality and improve the outcomes of surgical interventions for congenital heart disease. The prognostic value of immune disorders identified by the TREC/KREC method for infectious complications of cardiac surgery has not been studied. The purpose of this research was to assess the possibility of predicting infectious complications of cardiac surgery in children with congenital heart disease based on screening using the TREC/KREC method. Material and methods used: preoperatively, 200 children with congenital heart disease aged 3 days to 12 months old were examined. Instrumental and laboratory methods were used including immunological screening for TREC/KREC DNA. Results: 123 (62.4%) were diagnosed with “acyanotic” congenital heart disease, 74 (37.5%) with various cyanotic congenital heart diseases and 10 (5%) with congenital heart diseases with Down syndrome, Di George syndrome, Williams syndrome or multiple malformations. 184 (92%) underwent various cardiac surgical interventions. Violations of T-cell immunity according to preoperative TREC/KREC screening were observed in 23.5% of cases including in all children with syndromic forms of congenital heart disease, multiple malformations, and significantly more often in cyanotic congenital heart disease, conotruncal defects, and those admitted in critical conditions. Infectious complications of cardiac surgery were observed significantly more often in this group than in children with normal T-cell immunity (in 36% and 3.6%, respectively). Conclusion: the prognostic value of TREC/KREC screening for targeted preparation and postoperative management in order to prevent infectious complications of cardiac surgery has been confirmed.

Peri-operative cardiac arrest in children as reported to the 7th National Audit Project of the Royal College of Anaesthetists.

The 7th National Audit Project of the Royal College of Anaesthetists studied peri-operative cardiac arrest. An activity survey estimated UK paediatric anaesthesia annual caseload as 390,000 cases, 14% of the UK total. Paediatric peri-operative cardiac arrests accounted for 104 (12%) reports giving an incidence of 3 in 10,000 anaesthetics (95%CI 2.2-3.3 per 10,000). The incidence of peri-operative cardiac arrest was highest in neonates (27, 26%), infants (36, 35%) and children with congenital heart disease (44, 42%) and most reports were from tertiary centres (88, 85%). Frequent precipitants of cardiac arrest in non-cardiac surgery included: severe hypoxaemia (20, 22%); bradycardia (10, 11%); and major haemorrhage (9, 8%). Cardiac tamponade and isolated severe hypotension featured prominently as causes of cardiac arrest in children undergoing cardiac surgery or cardiological procedures. Themes identified at review included: inappropriate choices and doses of anaesthetic drugs for intravenous induction; bradycardias associated with high concentrations of volatile anaesthetic agent or airway manipulation; use of atropine in the place of adrenaline; and inadequate monitoring. Overall quality of care was judged by the panel to be good in 64 (62%) cases, which compares favourably with adults (371, 52%). The study provides insight into paediatric anaesthetic practice, complications and peri-operative cardiac arrest.

Recapitulation of human pathophysiology and identification of forensic biomarkers in a translational model of chlorine inhalation injury.

Chlorine gas (Cl2) has been repeatedly used as a chemical weapon, first in World War I and most recently in Syria. Life-threatening Cl2 exposures frequently occur in domestic and occupational environments, and in transportation accidents. Modeling the human etiology of Cl2-induced acute lung injury (ALI), forensic biomarkers, and targeted countermeasures development have been hampered by inadequate large animal models. The objective of this study was to develop a translational model of Cl2-induced ALI in swine to understand toxico-pathophysiology and evaluate whether it is suitable for screening potential medical countermeasures and to identify biomarkers useful for forensic analysis. Specific pathogen-free Yorkshire swine (30-40 kg) of either sex were exposed to Cl2 (≤240 ppm for 1 h) or filtered air under anesthesia and controlled mechanical ventilation. Exposure to Cl2 resulted in severe hypoxia and hypoxemia, increased airway resistance and peak inspiratory pressure, and decreased dynamic lung compliance. Cl2 exposure resulted in increased total leucocyte and neutrophil counts in bronchoalveolar lavage fluid, vascular leakage, and pulmonary edema compared with the air-exposed group. The model recapitulated all three key histopathological features of human ALI, such as neutrophilic alveolitis, deposition of hyaline membranes, and formation of microthrombi. Free and lipid-bound 2-chlorofatty acids and chlorotyrosine-modified proteins (3-chloro-l-tyrosine and 3,5-dichloro-l-tyrosine) were detected in plasma and lung tissue after Cl2 exposure. In this study, we developed a translational swine model that recapitulates key features of human Cl2 inhalation injury and is suitable for testing medical countermeasures, and validated chlorinated fatty acids and protein adducts as biomarkers of Cl2 inhalation.NEW & NOTEWORTHY We established a swine model of chlorine gas-induced acute lung injury that exhibits several features of human acute lung injury and is suitable for screening potential medical countermeasures. We validated chlorinated fatty acids and protein adducts in plasma and lung samples as forensic biomarkers of chlorine inhalation.

Polysomnographic characteristics of excessive daytime sleepiness phenotypes in obstructive sleep apnea: Results from the international Sleep Apnea Global Interdisciplinary Consortium (SAGIC).

Excessive daytime sleepiness (EDS) is a major symptom of obstructive sleep apnea (OSA). Traditional polysomnographic (PSG) measures only partially explain EDS in OSA. This study analyzed traditional and novel PSG characteristics of two different measures of EDS among OSA patients. Sleepiness was assessed using the Epworth Sleepiness Scale (>10 points defined as "risk of dozing") and a measure of general sleepiness (feeling sleepy ≥3 times/week defined as "feeling sleepy"). Four sleepiness phenotypes were identified: "non-sleepy", "risk of dozing only", "feeling sleepy only" and "both at risk of dozing and feeling sleepy". Altogether, 2083 OSA patients (69% male) with an apnea-hypopnea index (AHI) ≥5 events/hour were studied; 46% were "non-sleepy", 26% at "risk of dozing only", 7% were "feeling sleepy only" and 21% reported both. The two phenotypes at "risk of dozing" had higher AHI, more severe hypoxemia (as measured by oxygen desaturation index, minimum and average oxygen saturation [SpO2], time spent <90% SpO2, and hypoxic burden) and they spent less time awake, had shorter sleep latency, and higher heart rate response to arousals than "non-sleepy" and "feeling sleepy only" phenotypes. While statistically significant, effect sizes were small. Sleep stages, frequency of arousals, wake after sleep onset and limb movement did not differ between sleepiness phenotypes after adjusting for confounders. In a large international group of OSA patients, PSG characteristics were weakly associated with EDS. The physiological measures differed among individuals characterized as "risk of dozing" or "non-sleepy", while "feeling sleepy only" did not differ from "non-sleepy" individuals.