Lowest Arterial Oxygen Saturation Research Articles

Pediatric high-altitude pulmonary edema and acute mountain sickness: Clinical features and risk determinants.

This investigation aimed to delineate the clinical manifestations associated with high-altitude pulmonary edema (HAPE) and acute mountain sickness (AMS) in pediatric populations and find the risk factors of HAPE. We conducted a retrospective analysis of clinical data from children under 18 years diagnosed with HAPE and AMS at an average altitude of 3000 m. The clinical data between these two groups were compared. The study encompassed 74 pediatric patients, 27 with AMS and 47 with HAPE. HAPE presentations included classic HAPE (55.3%), reentry HAPE (27.7%), and high-altitude resident pulmonary edema (HARPE, 17.0%). Notably, 87.2% of HAPE cases were male, and 68.1% had a high body mass index (BMI). HARPE instances followed viral infections, prominently SARS-CoV-2. HAPE cases exhibited higher BMI, respiratory tract infections within 1 week preceding symptom onset, an increase in white blood cell counts (WBCs), lower peripheral arterial oxygen saturation (SpO2), and higher heart rate compared to the AMS group. Multivariate logistic regression pinpointed high BMI as an independent HAPE risk factor (odds ratio = 19.389, 95% confidence interval: 1.069-351.759, p = .045). HAPE occurs predominantly in males, with high BMI identified as a critical independent risk factor. The study underscores the need for heightened awareness and preventive strategies against HAPE in children at high altitudes.

Clinical Manifestations Laboratory Tests Abdominal Ultrasonic Findings and In-hospital Prognosis of COVID-19 in 185 Pediatric Cases in a Tertiary Center.

Despite the COVID-19 pandemic, there is little information about the different clinical aspects of COVID-19 in children. In this study, we assessed the clinical manifestations, outcome, ultrasound, and laboratory findings of pediatric COVID-19. This retrospective study was conducted on 185 children with definitive diagnosis of COVID-19 between 2021 and 2022. The patients' information was retrieved from hospital records. The average age of the patients was 5.18 ± 4.55 years, and 61.1% were male. The most frequent clinical manifestation was fever (81.1%) followed by cough (31.9%), vomiting (20.0%), and diarrhea (20.0%). Mesenteric lymphadenitis was common on ultrasound and found in 60% of cases. In-hospital death was identified in 3.8% of cases. The mean length of hospital stay was 8.5 days. Mandating intensive care unit (ICU) stay was found in 19.5% and 5.9% of cases were intubated. Acute respiratory distress syndrome (ARDS), lower arterial oxygen saturation, higher white blood cell (WBC) count, and higher C-reactive protein (CRP) were the main determinants of death. Lower age, respiratory distress, early onset of clinical manifestations, lower arterial oxygen saturation, lower serum hemoglobin (Hb) level, and higher CRP level could predict requiring ICU admission. We recommend close monitoring on CRP, serum Hb level, WBC count, and arterial level of oxygenation as clinical indicators for potential progression to critical illness and severe disease. Mesenteric lymphadenitis is a common sonographic finding in pediatric COVID-19 which can cause abdominal pain. Ultrasound is helpful to avoid unnecessary surgical interventions in COVID-19.

Mechanisms of limitation of oxygen delivery during veno-venous extracorporal membrane oxygenation.

Delivery of oxygen to the mitochondrium is a process involving multiple steps. We here present the integration of the mechanisms of oxygen delivery (DO2) during veno-venous (V-V) extracorporal membrane oxygenation (ECMO) into a holistic physiological model. The final steps of oxygen transport in this model are the convective transport of oxygen bound to hemoglobin in the arterial blood and the diffusion to the mitochondrium from the microcirculation. Limitation of DO2 may occur on both steps. In cases of severe respiratory failure without lung function, ECMO may provide the entire oxygen supply for the patients. If the cardiac output (CO) is significantly higher than the maximal ECMO flow, the addition of deoxygenated venous blood will lead to a low arterial oxygen saturation (SaO2). In this situation the convective transport of oxygen is mostly limited by the maximal ECMO flow. If a bi-caval dual lumen cannula is used, the recirculation may be very low. Lowering the CO in this situation will increase the arterial SaO2. An increased arterial SaO2 may increase the oxygen transport to the mitochondrium by diffusion. The hypothesis derived from this model is that lowering the CO during V-V ECMO support in the situation described above might increase DO2 to the tissues by improving oxygen diffusion.

Evaluation of the Prevalence and Predictive Factors of Post-COVID Cognitive Disorders Among Iranian COVID-19 Recuperated Individuals: A Bayesian Analysis

Background: Coronavirus disease 2019 (COVID-19), as a global crisis, has impacted all aspects of human life, even long after its universal containment. Among these impacts, COVID-related cognitive disorders (CDs) are significant, particularly when they persist over the long term. Cognitive disorders are characterized by the brain’s inability to process, store, and utilize information for reasoning, judgment, perception, attention, comprehension, and memory. Objectives: Given the persistence of COVID-related CDs even long after recovery, this study aimed to determine the prevalence and predictive factors of CDs among individuals who had recovered from COVID-19 in Iran, using Bayesian analysis. Methods: In this regional cross-sectional analytical study, 300 individuals were randomly selected from three hospitals in Tehran, Iran. The subjects were evaluated using the Clinical Demographic Information Questionnaire, Montreal Cognitive Assessment (MoCA), the Pittsburgh Sleep Quality Index (PSQI), the Obsessive-Compulsive Inventory-Revised (OCI-R), the Depression, Anxiety, and Stress Scale 21 (DASS-21), and the Posttraumatic Stress Disorder (PTSD) Checklist for DSM-5 (PCL-5). The obtained data were analyzed using SPSS software (version 26) to determine the prevalence of CDs, identify predictive factors, and examine the interrelationship between CDs and other COVID-related disorders. Results: Among the 300 participants, only 81 individuals (27%) exhibited CDs. The majority of the aforementioned subjects were patients at hospital A (46.91%), and their recovery occurred between 12-18 months ago (39.51%). Among these variables, only the difference in the hospital variable was statistically significant (P = 0.001). Furthermore, there were correlations between CDs and obsessive-compulsive disorder (OCD), anxiety, and stress, although they were not statistically significant. Ultimately, PTSD (BF = 0.58, P = 0.02), older age (BF = 0.0001, P = 0.0001), hospitalization at hospital A (BF = 0.35, P = 0.001), lower arterial oxygen saturation (SaO2) (BF = 0.01, P = 0.0001), and longer hospitalization (BF = 0.001, P = 0.0001) were identified as the most robust predictors for the presence of CDs among individuals recovering from COVID-19. Conclusions: In conclusion, CDs were observed in less than half (27%) of individuals who had recovered from COVID-19. Sociodemographic and health disparities contributed to variations in the prevalence, severity, and significance of these disorders.

Cardiac troponin in hospitalized COVID-19 patients: Incidence, predictors, and outcomes

Background The incidence, predictors, and association of cardiac troponin with mortality in hospitalized COVID-19 were not adequately studied in the past and were also not reported from an Indian hospital. Methods In this retrospective cohort study, the cardiac troponin of 240 hospitalized COVID-19 patients was measured. The incidence, predictors, and association of elevated cardiac troponin with in-hospital mortality were determined among hospitalized COVID-19 patients. Results The cardiac troponin was elevated in 12.9% (31/240) of the patients. The troponin was elevated in the patients in the older age group (64 years vs. 55 years, p = .002), severe COVID-19 illness (SpO2 < 90%) (93.5% vs. 60.8%, p < .001), low arterial oxygen saturation (SpO2) (80% vs. 88%, p = .001), and low PaO2/FiO2 ratio ( p < .0001). The patients with elevated cardiac troponin had elevated total leukocyte counts (TLC) ( p = .001), liver enzyme ( p = .025), serum creatinine ( p = .011), N-terminal-Pro Brain natriuretic peptide ( p < .0001), and d-dimer ( p < .0001). The majority of the patients with elevated cardiac troponin were admitted to the intensive care unit (90.3% vs. 51.2%; p < .0001), were on a ventilator (61.3% vs. 21.5%; p < .0001), and had higher mortality (64.5% vs. 19.6%; p < .0001). The Kaplan–Meir survival analysis showed that the patients with elevated troponin had worse survival ( p log-rank<.0001). Age, NT-ProBNP, d-dimer, and ventilator were the predictors of elevated troponin in multivariate logistic regression analysis. The Cox-regression analysis showed a significant association between elevated cardiac troponin and in-hospital mortality (adjusted hazard ratio 2.13; 95% confidence interval [CI] 1.145–3.97; p = .017). Two-thirds (65%) of patients with elevated cardiac troponin died during their hospital stay. Conclusions COVID-19 patients with elevated cardiac troponin had severe COVID illness, were more commonly admitted to an intensive care unit, were on a ventilator, and had high in-hospital mortality.

Endotoxemia Correlates with Kidney Function and Length of Stay in Critically Ill Patients

Introduction: Endotoxin is a key driver of sepsis, which frequently causes acute kidney injury (AKI). However, endotoxins may also be found in non-bacteremic critically ill patients, likely from intestinal translocation. Preclinical models show that endotoxins can directly injure the kidneys, and in COVID-19 patients, endotoxemia correlated with AKI. We sought to determine correlations between endotoxemia and kidney and hospital outcomes in a broad group of critically ill patients. Methods: In this single-center, serial prospective study, 124 predominantly Caucasian adult patients were recruited within 48 h of admission to Stony Brook University Hospital Intensive Care Unit (ICU). Demographics, vital signs, laboratory data, and outcomes were collected. Circulating endotoxin was measured on days 1, 4, and 8 using the endotoxin activity assay (EAA). The association of EAA with outcomes was examined with EAA: (1) categorized as <0.6, ≥0.6, and nonresponders (NRs); and (2) used as a continuous variable. Results: Patients with EAA ≥0.6 had a higher prevalence of proteinuria, and lower arterial oxygen saturation (SaO₂) to fraction of inspired oxygen (FiO₂) (SaO₂/FiO₂) ratio versus patients with EAA <0.6. EAA levels positively correlated with serum creatinine (sCr) levels on day 1. Patients whose EAA level stayed ≥0.6 had a slower decline in sCr compared to those whose EAA started at ≥0.6 and subsequently declined. Patients with AKI stage 1 and EAA ≥0.6 on day 1 showed slower decline in sCr compared to patients with stage 1 AKI and EAA <0.6. EAA ≥0.6 and NR patients had longer hospital stay and delayed ICU discharge versus EAA <0.6. Conclusions: High EAA levels correlated with worse kidney function and outcomes. Patients whose EAA levels fell, and those with AKI stage I and day 1 EAA <0.6 recovered more quickly compared to those with EAA ≥0.6, suggesting that removal of circulating endotoxins may be beneficial in critically ill patients.

Excessive daytime sleepiness in young and middle-aged Chinese adults with obstructive sleep apnea: implications for cognitive dysfunction.

The objective of this study was to investigate the effects of excessive daytime sleepiness (EDS) on cognitive function among Chinese young and middle-aged Chinese patients with obstructive sleep apnea (OSA). Chinese adults struggling from moderatetosevere OSAwith apnea-hypopnea index (AHI)≥ 15 events per hour and adults with primary snoring and mild OSA (AHI< 15 events per hour) were included in the study. The Epworth Sleepiness Scale measured hypersomnia, and cognitive function was assessed using the Mini-mental State Examination (MMSE) and Montreal Cognitive Assessment (MOCA). Incomparison to the primary snoring and mild OSA group(n=635), the moderatetosevere OSA group (n=1423) tended to be older men with higher scores on the Epworth Sleepiness Scale (ESS), as well as higher levels of oxygen desaturation (ODI) and a higher body mass index (BMI). Patients with moderate to severe OSA had fewer years of education, lower minimum arterial oxygen saturation (min-SaO2), and more severe sleep disturbances, such as decreased slow wave sleep (SWS) and rapid eye movement (REM) and increased non-REM stages (N1 and N2). Comorbid conditions such as hypertension and diabetes mellitus were more common in these patients (P < 0.01 and P < 0.05, accordingly). Only the delayed recall scores were statistically lower in the moderatetosevere OSA group than the primary snoring and mild OSA group (P < 0.05). The main factor associated with delayed recall was the ESS score rather than age or years of education among moderate-severe OSA patients ≤ 40years of age (P < 0.05). After controlling for potential confounding factors such as age, gender, BMI, education, hypertension, diabetes, sleep stages (SWS and REM), minimum arterial oxygen saturation (min-SaO2), oxygen ODI, and AHI, there was a negative correlation between the Epworth Sleepiness Scale (ESS) score and the delayed recall scores. Patients with moderatetosevere OSA hadcognitive dysfunction, particularly impairment of delayed recall. Excessive daytime sleepiness (EDS) was significantly associated with cognitive dysfunction in young and middle-aged patients withOSA.

Oral Ketamine or Nasal Midazolam for Sedation in Pediatric Upper Gastrointestinal Endoscopy

Background: There is no agreement on the route of administration and the drug of choice for providing adequate sedation for pediatric invasive procedures. Objectives: We compared the utility, safety, and sedation effects of intranasal midazolam and oral ketamine. Materials &amp; Methods: This double-blind clinical trial was performed on 100 children aged 2 to 14 years who were candidates for upper gastrointestinal (GI) endoscopy. Patients were randomly assigned to two groups: ketamine (4 mg/kg orally) and midazolam (0.1 mg/ kg intranasal). Sedation score, fear levels, children’s behavior at the time of separation from parents, and vital signs were recorded. Results: Higher systolic blood pressure was seen in children who received ketamine (P=0.012) and lower arterial oxygen saturation in the midazolam group (P=0.023). Also, the level of sedation showed no significant difference between the groups. Conclusion: Based on the results, administering oral ketamine or intranasal midazolam before endoscopy induced a similar sedation score in children. Also, both methods could be safe and non-invasive modalities for sedation.

Efficacy Analysis of Extended Uvulopalatopharyngoplasty Combined With the Simultaneous Multiplane Operation to Treat Obstructive Sleep Apnea.

The purpose of this study was to discuss the safety and long-term efficacy of extended uvulopalatopharyngoplasty combined with the simultaneous multiplane operation to treat obstructive sleep apnea (OSA). Sixty-two patients confirmed with OSA by polysomnography received physical examinations, determination of nasal resistance, Muller's maneuver under electronic laryngoscope, and upper airway computed tomography scan to locate the obstruction planes. Then the patients received extended uvulopalatopharyngoplasty combined with the simultaneous multiplane operation of the nasal cavity and/or tongue root under general anesthesia. Body mass index, Epworth Sleepiness Scale (ESS) score, apnea-hypopnea index (AHI), and lowest arterial oxygen saturation (LSaO 2 ) were compared before and after surgery. Postoperative complications were recorded. All patients were followed up for 12 to 24 months after surgery. The above-mentioned indicators were determined. Fourteen patients (22.58%) achieved a cure, 20 patients (32.26%) marked effectiveness, 20 patients (32.26%) moderate effectiveness, and 8 patients (12.90%) ineffectiveness. The overall response rate was 87.10%. AHI and ESS score decreased, and LSaO 2 increased after surgery than before, all in a significant manner ( P <0.05). There was no significant difference in body mass index before and after surgery. No severe complications occurred in any patients. Extended uvulopalatopharyngoplasty combined with the simultaneous multiplane operation had a good safety for OSA, improving ESS, AHI, and LSaO 2 significantly. The patients enjoyed an improved life quality after surgery.

Association of Hypovitaminosis D with Sleep Parameters in Rotating Shift Worker Drivers.

Objective To evaluate the association between sleep parameters and hypovitaminosis D in rotating shift drivers. Material and Methods We conducted a cross-sectional study on 82 male rotating shift workers (24-57 years old) with at least one cardiovascular risk factor (such as hyperglycemia, dyslipidemia, abdominal obesity, physical inactivity, hypertension, and smoking). Polysomnography was used to evaluate sleep parameters. Logistic regression was used to model the association between hypovitaminosis D and sleep parameters after adjustment for relevant covariates. Results Hypovitaminosis D (< 20 ng/mL) was seen in 30.5% of the workers. Shift workers with hypovitaminosis D had lower sleep efficiency (odds ratio [OR]: 3.68; 95% confidence interval [CI]: 1.95-5.53), lower arterial oxygen saturation (OR: 5.35; 95% CI: 3.37-6.12), and increased microarousal index (OR: 3.85; 95% CI: 1.26-5.63) after adjusting. Conclusion We suggest that hypovitaminosis D is associated with greater sleep disturbances in rotating shift workers.

Optimal Settings at Initiation of Veno-Venous Extracorporeal Membrane Oxygenation: An Exploratory In-Silico Study.

The Extracorporeal Life Support Organisation (ELSO) recommends initiating veno-venous extracorporeal membrane oxygenation (ECMO) with sweep gas flow rate () of 2 L/min and extracorporeal circuit blood flow () of 2 L/min. We used an in-silico model to examine the effect on gas exchange of initiating ECMO with different and , and the effect of including 5% in sweep gas. This was done using a set of patient examples, each with different physiological derangements at baseline (before ECMO). When ECMO was initiated following ELSO recommendations in the patient examples with significant hypercapnia at baseline, sometimes fell to < 50% of the baseline , a magnitude of fall associated with adverse neurological outcomes. In patient examples with very low baseline arterial oxygen saturation (), initiation of ECMO did not always increase to > 80%. Initiating ECMO with of 1 L/min and of 4 L/min, or with sweep gas containing 5% , of 2 L/min, and of 4 L/min, reduced the fall in and increased the rise in compared to the ELSO strategy. While ELSO recommendations may suit most patients, they may not suit patients with severe physiological derangements at baseline.

The Association of Seasonal Variations and COVID-19 Clinical Features: A Comparative Study on the Fourth and Fifth Waves.

The COVID-19 pandemic has overwhelmed many healthcare systems. Seasonality is a feature of several infectious diseases. Studies regarding the association of seasonal variations and COVID-19 have shown controversial results. Therefore, we aimed to compare COVID-19 characteristics and survival outcomes between the fourth and fifth waves in Iran, which corresponded to spring and summer, respectively. This is a retrospective study on the fourth and fifth COVID-19 waves in Iran. One hundred patients from the fourth and 90 patients from the fifth wave were included. Data from the baseline and demographic characteristics, clinical, radiological, and laboratory findings, and hospital outcomes were compared between the fourth and fifth COVID-19 waves in hospitalized patients in Imam Khomeini Hospital Complex, Tehran, Iran. The fifth wave patients were more likely to present with gastrointestinal symptoms than the patients from the fourth wave. Moreover, patients in the fifth wave had lower arterial oxygen saturation on admission (88% vs. 90%; P = 0.026), lower levels of WBCs (neutrophils and lymphocytes) (6300.00 vs. 8000.00; P = 0.004), and higher percentages of pulmonary involvement in the chest CT scans (50% vs. 40%; P < 0.001). Furthermore, these patients had longer hospital stays than their fourth-wave counterparts (7.00 vs. 5.00; P < 0.001). Our study indicated that patients in the summer COVID-19 wave were more likely to present with gastrointestinal symptoms. They also experienced a more severe disease in terms of peripheral capillary oxygen saturation, percentages of pulmonary involvement in CT scans, and length of hospital stay.

Clinical Evaluation of the Medium-Term Efficacy of Laparoscopic Sleeve Gastrectomy against Obstructive Sleep Apnea-Hypopnea Syndrome in Obese Patients.

Objective This study was designed to evaluate the efficacy of laparoscopic sleeve gastrectomy (LSG) for obstructive sleep apnea-hypopnea syndrome (OSAHS) in obese individuals and identify the related factors affecting its efficacy. Methods The clinical and follow-up data of 37 obese patients with OSAHS who underwent LSG in the Laparoscopic Surgery Department of Zibo Central Hospital from January 2017 to July 2018 were analyzed retrospectively. The effect of this operation on patients' weight and OSAHS was studied, and the factors affecting weight and OSAHS were examined through univariate and multivariate logistic regression analysis. Results Over 12 months of regular postoperative follow-up with the 37 patients, their body mass index (BMI) decreased, and the percentage of excess weight loss (EWL%) reached 73.2%. Additionally, the rate of successful OSAHS treatment reached 91.89%, and the apnea-hypopnea index (AHI) and lowest arterial oxygen saturation (LSaO2) increased significantly. Univariate logistic regression analysis showed that gender, weight, EWL%, and smoking affected the efficacy of LSG against OSAHS (P < 0.05). EWL% and smoking were independent factors that helped determine the efficacy of LSG against morbid obesity (P < 0.05). Conclusion LSG can effectively help obese patients lose weight and show medium-term efficacy against OSAHS in obese people. Smoking and EWL% were found to be the factors determining the efficacy of LSG.

Short-term prognostic value of clinical data in hospitalized patients with intermediate-risk acute pulmonary embolism

BackgroundIntermediate-risk acute pulmonary embolism (APE) patients are usually defined as hemodynamically stable, comprehending a great therapeutic dilemma. Although anticoagulation therapy is sufficient for most intermediate-risk APE patients, some patients can deteriorate and eventually require a systemic fibrinolytic agent or thrombectomy. Hence, this study aimed to evaluate the predictive value of differences in clinical data for the short-term prognosis of intermediate-risk APE patients.MethodsA retrospective cohort of 74 intermediate-risk APE patients confirmed by computed tomography pulmonary angiography was analyzed in the present study. Adverse clinical event outcomes included PE-related in-hospital deaths, critical systolic blood pressure consistently under 90 mmHg, refractory to volume loading and vasopressor infusion requirements, mechanical ventilation, and cardiopulmonary resuscitation. The APE patients were stratified into two groups: adverse outcome (n = 25) and control (n = 49) groups. Then, the clinical data of the two groups were compared. Receiver operating characteristic (ROC) curves were used to explore the predictive value of white blood cell (WBC) counts and the right to left ventricular short-axis (RV/LV) ratio. Model calibration was assessed using the Hosmer–Lemeshow goodness-of-fit statistic.ResultsThe brain natriuretic peptide, WBC count, and the RV/LV ratio were higher in patients with adverse outcomes compared to controls. The APE patients with adverse outcomes presented significantly higher rates of syncope, Negative T waves (NTW) in V1–V3, intermediate-high risk, thrombolytic therapy, and low arterial oxygen saturation (SaO2) compared to controls. In the multivariate logistic regression analysis, the SaO2 < 90%, [odds ratio (OR) 5.343, 95% confidence interval (CI) 1.241–23.008; p = 0.024], RV/LV ratio (OR 7.429, 95% CI 1.145–48.209; p = 0.036), Syncope (OR 12.309, 95% CI 1.702–89.032; p = 0.013), NTW in V1–V3 (OR 5.617, 95% CI 1.228–25.683; p = 0.026), and WBC count (OR 1.212, 95% CI 1.035–1.419; p = 0.017) were independent predictors of in-hospital adverse outcomes among APE patients. The ROC curve analysis indicated that the RV/LV ratio can be used to predict adverse outcomes (AUC = 0.748, p < 0.01) and calibration (Hosmer–Lemeshow goodness of fit test, p = 0.070). Moreover, an RV/LV ratio > 1.165 was predictive of adverse outcomes with sensitivity and specificity of 88.00 and 59.20%, respectively. The WBC counts were also able to predict adverse outcomes (AUC = 0.752, p < 0.01) and calibration (Hosmer–Lemeshow goodness of fit test, p = 0.251). A WBC count > 9.05 was predictive of adverse outcomes with sensitivity and specificity of 68.00 and 73.50%, respectively.ConclusionOverall, a SaO2 < 90%, RV/LV ratio, Syncope, NTW in V1–V3, and WBC counts could independently predict adverse outcomes in hospitalized intermediate-risk APE patients.

How does multi-set high-load resistance exercise impact neuromuscular function in normoxia and hypoxia?

ABSTRACT This study examined whether hypoxia during multi-set, high-load resistance exercise alters neuromuscular responses. Using a single-blinded (participants), randomised crossover design, eight resistance-trained males completed five sets of five repetitions of bench press at 80% of one repetition maximum in moderate normobaric hypoxia (inspiratory oxygen fraction = 0.145) and normoxia. Maximal isometric bench press trials were performed following the warm-up, after 10 min of altitude priming and 5 min post-session (outside, inside and outside the chamber, respectively). Force during pre-/post-session maximal voluntary isometric contractions and bar velocity during exercise sets were measured along with surface electromyographic (EMG) activity of the pectoralis major, anterior deltoid and lateral and medial triceps muscles. Two-way repeated measures ANOVA (condition×time) were used. A significant time effect (p = 0.048) was found for mean bar velocity, independent of condition (p = 0.423). During sets of the bench press exercise, surface EMG amplitude of all studied muscles remained unchanged (p > 0.187). During maximal isometric trials, there were no main effects of condition (p > 0.666) or time (p > 0.119), nor were there any significant condition×time interactions for peak or mean forces and surface EMG amplitudes (p > 0.297). Lower end-exercise blood oxygen saturation (90.9 ± 1.8 vs. 98.6 ± 0.6%; p < 0.001) and higher blood lactate concentration (5.8 ± 1.4 vs. 4.4 ± 1.6 mmol/L; p = 0.007) values occurred in hypoxia. Acute delivery of systemic normobaric hypoxia during multi-set, high-load resistance exercise increased metabolic stress. However, only subtle neuromuscular function adjustments occurred with and without hypoxic exposure either during maximal isometric bench press trials before versus after the session or during actual exercise sets. Highlights Performing multi-set, high-load bench press resistance exercise in hypoxia accentuates metabolic stress, as evidenced by lower arterial oxygen saturation and higher blood lactate concentration, compared to normoxia. Acute hypoxic exposure doesn’t alter neuromuscular responses during the execution of the sets since mean bar velocity dropped similarly in both conditions from set 2 to set 5 with no difference in peak velocity and surface EMG amplitude of the prime movers during the bench press. Only subtle adjustments in peak or mean force and accompanying surface EMG activity occur with and without hypoxic exposure during maximal isometric bench press trials after a 10-min hypoxic priming period and 5 min after the session in reference to post-warm-up.

The Efficacy of Twin-Block Appliances for the Treatment of Obstructive Sleep Apnea in Children: A Systematic Review and Meta-Analysis.

Objective To evaluate the efficacy of twin-block appliance in the treatment of children with obstructive sleep apnea (OSA). Methods Two independent reviewers conducted a systematic review of seven databases from database establishment until October 16, 2021. There were no language restrictions. The outcomes were changes in apnea-hypopnea index (AHI), oxyhemoglobin desaturation index (ODI), and lowest arterial oxygen saturation (lowest SaO2). National Institute for Health and Clinical Excellence (NICE) tool was used to assess the quality of the studies included. Results A total of 207 articles were screened for relevance, and 6 of them met the inclusion criteria for our meta-analysis. Four of the studies were case series, 1 was nonrandomized control trial, and 1 was a randomized crossover clinical trial. After twin-block therapy, there was a significant decrease in AHI (4.35 events/hour, 95% CI: 4.04, 4.66, p ≤ 0.001). The lowest SaO2 significantly increased by 9.17% (95% CI: 12.05, 6.28, p ≤ 0.001). Sensitivity analysis by excluding studies one by one showed stable and favorable results in lowest SaO2 and AHI. Conclusions Results from the meta-analysis showed that the use of twin-block appliance significantly decreased AHI and significantly increased lowest SaO2. Hence, twin-block appliance therapy may be an effective method for the treatment of pediatric OSA. Further large sample size randomized controlled trials are needed to assess this treatment efficacy in children with obstructive sleep apnea.

Impact of hypoxemia and re-interventions on clinical outcomes after bidirectional cavopulmonary shunt.

We sought to investigate the impact of early postoperative low arterial oxygen saturation on mortality and morbidity after bidirectional cavopulmonary shunt (BCPS). The medical records of all patients who underwent BCPS between 2013 and 2018 were reviewed. A total of 164 patients were included in this study. Forty-seven patients underwent reintervention during hospital stay at median 7 days after BCPS. Before reintervention, 30 patients were intubated or had SpO2 of <75%. All re-interventions for Glenn pathway obstruction and 4 out of 5 venovenous coil embolization resulted in hospital discharge, while high mortality was observed after other re-interventions (atrioventricular valve surgery, thrombolysis, systemic ventricular outflow obstruction relief, extracorporeal membrane oxygenation implantation and diaphragmatic plication). Additional aortopulmonary shunt with pulmonary artery discontinuation was performed in 8 patients who showed severe cyanosis with median SpO2 of 59% under maximal ventilation support. In the univariable Cox regression analysis, the associated factors for mortality before total cavopulmonary connection were reduced ventricular function [hazard ratio (HR) 6.89, 95% confidence interval (CI) 1.76-26.9, P-value 0.006], greater than moderate atrioventricular valve regurgitation (HR 5.89, 95% CI 1.70-20.4, P-value 0.005), SpO2 1 h after extubation (HR 0.87, 95% CI 0.80-0.96, P-value 0.004) and mean pulmonary artery pressure 1 h after extubation (HR 1.14, 95% CI 1.02-1.26, P-value 0.016). After BCPS, unacceptable cyanosis persisted with various aetiologies. Low arterial oxygen saturation within 1 h after extubation is significantly associated with high mortality after BCPS.

Development and Validation of a Prognostic Nomogram in Lung Cancer With Obstructive Sleep Apnea Syndrome.

To analyze the prognostic factors and survival rate of lung cancer patients with obstructive sleep apnea (OSA) by nomogram. The nomogram was established by a development cohort (n = 90), and the validation cohort included 38 patients. Factors in the nomogram were identified by Cox hazard analysis. We tested the accuracy of the nomograms by discrimination and calibration, and plotted decision curves to assess the benefits of nomogram-assisted decisions. There were significant difference in sex, apnea hypopnea index (AHI), Tumor Node Metastasis (TNM), coronary heart disease, lowest arterial oxygen saturation [LSpO2 (%)], oxygen below 90% of the time [T90% (min)], the percentage of the total recorded time spend below 90% oxygen saturation (TS90%) and oxygen desaturation index (ODI4) between lung cancer subgroup and lung cancer with OSA subgroup (P < 0.05). Lung cancer patients with OSA age, AHI, TNM, cancer types, BMI and ODI4 were independent prognostic factor. Based on these six factors, a nomogram model was established. The c-index of internal verification was 0.802 (95% CI 0.767–0.885). The ROC curve analysis for the nomogram show 1-year survival (AUC = 0.827), 3-year survival (AUC = 0.867), 5-year survival (AUC = 0.801) in the development cohort were good accuracy. The calibration curve shows that this prediction model is in good agreement. Decision curve analysis (DCA) suggests that the net benefit of decision-making with this nomogram is higher, especially in the probability interval of <20% threshold. The nomogram can predict the prognosis of patients and guide individualized treatment.

Effects of Vagus Nerve Stimulation on Sleep-Disordered Breathing, Daytime Sleepiness, and Sleep Quality in Patients With Drug-Resistant Epilepsy.

Background and PurposeThis study aimed to determine the long-term effects of vagus nerve stimulation (VNS) on sleep-disordered breathing (SDB), daytime sleepiness, and sleep quality in patients with drug-resistant epilepsy (DRE). It also investigated the relationships among these main effects, clinical characteristics, and VNS parameters.MethodsTwenty-four patients were recruited. Paired t-tests and multiple linear regression analyses were performed to determine how the demographic and clinical characteristics of the patients influenced the variables that changed significantly after VNS treatment.ResultsAfter VNS, the patients showed significant increases in the apnea-hypopnea index (AHI), respiratory disturbance index (RDI), apnea index, hypopnea index, and oxygen desaturation index (ODI), as well as a significant decrease in the lowest arterial oxygen saturation (SaO2 nadir) (p<0.05). The multiple linear regression analyses demonstrated that the predictor of larger increases in AHI and RDI was being older at baseline, and that the predictor of a larger increase in apnea index was a longer epilepsy duration. The strongest predictor of a larger increase in ODI was a higher frequency of aura episodes at baseline, followed by a longer epilepsy duration. The strongest predictor of a larger decrease in SaO2 nadir was a higher frequency of aura episodes at baseline, followed by a longer epilepsy duration.ConclusionsThis study has confirmed that VNS improves seizure control in patients with DRE, whereas it increases obstructive sleep apnea (OSA). Furthermore, the increase in OSA is affected by age and the duration of epilepsy. Therefore, careful observation and monitoring of SDB is recommended in patients who undergo VNS.

Enhanced Ocular Surface and Intraoral Nociception via a Transient Receptor Potential Vanilloid 1 Mechanism in a Rat Model of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA), characterized by low arterial oxygen saturation during sleep, is associated with an increased risk of orofacial pain. In this study, we simulated chronic intermittent hypoxia (CIH) during the sleep/rest phase (light phase) to determine the role of transient receptor potential vanilloid 1 (TRPV1) in mediating enhanced orofacial nocifensive behavior and trigeminal spinal subnucleus caudalis (Vc) neuronal responses to capsaicin (a TRPV1 agonist) stimulation in a rat model of OSA. Rats were subjected to CIH (nadir O2, 5%) during the light phase for 8 or 16 consecutive days. CIH yielded enhanced behavioral responses to capsaicin after application to the ocular surface and intraoral mucosa, which was reversed under normoxic conditions. The percentage of TRPV1-immunoreactive trigeminal ganglion neurons was greater in CIH rats than in normoxic rats and recovered under normoxic conditions after CIH. The ratio of large-sized TRPV1-immunoreactive trigeminal ganglion neurons increased in CIH rats. The density of TRPV1 positive primary afferent terminals in the superficial laminae of Vc was higher in CIH rats. Phosphorylated extracellular signal-regulated kinase (pERK)-immunoreactive cells intermingled with the central terminal of TRPV1-positive afferents in the Vc. The number of pERK-immunoreactive cells following low-dose capsaicin (0.33 µM) application to the tongue was significantly greater in the middle portion of the Vc of CIH rats than of normoxic rats and recovered under normoxic conditions after CIH. These data suggest that CIH during the sleep (light) phase is sufficient to transiently enhance pain on the ocular surface and intraoral mucosa via TRPV1-dependent mechanisms.