Physiological and clinical effects of trunk inclination adjustment in patients with respiratory failure: a scoping review and narrative synthesis.

BACKGROUND: Adjusting trunk inclination from a semi-recumbent position to a supine-flat position or vice versa in patients with respiratory failure significantly affects numerous aspects of respiratory physiology including respiratory mechanics, oxygenation, end-expiratory lung volume, and ventilatory efficiency. Despite these observed effects, the current clinical evidence regarding this positioning manoeuvre is limited. This study undertakes a scoping review of patients with respiratory failure undergoing mechanical ventilation to assess the effect of trunk inclination on physiological lung parameters. METHODS: The PubMed, Cochrane, and Scopus databases were systematically searched from 2003 to 2023. INTERVENTIONS: Changes in trunk inclination. MEASUREMENTS: Four domains were evaluated in this study: 1) respiratory mechanics, 2) ventilation distribution, 3) oxygenation, and 4) ventilatory efficiency. RESULTS: After searching the three databases and removing duplicates, 220 studies were screened. Of these, 37 were assessed in detail, and 13 were included in the final analysis, comprising 274 patients. All selected studies were experimental, and assessed respiratory mechanics, ventilation distribution, oxygenation, and ventilatory efficiency, primarily within 60 min post postural change. CONCLUSION: In patients with acute respiratory failure, transitioning from a supine to a semi-recumbent position leads to decreased respiratory system compliance and increased airway driving pressure. Additionally, C-ARDS patients experienced an improvement in ventilatory efficiency, which resulted in lower PaCO2 levels. Improvements in oxygenation were observed in a few patients and only in those who exhibited an increase in EELV upon moving to a semi-recumbent position. Therefore, the trunk inclination angle must be accurately reported in patients with respiratory failure under mechanical ventilation.

Analysis of Vancomycin Dosage and Plasma Levels in Critically Ill Adult Patients Requiring Extracorporeal Membrane Oxygenation (ECMO).

Introduction: Critically ill patients undergoing extracorporeal membrane oxygenation (ECMO) exhibit unique pharmacokinetics. This study aimed to assess the achievement of vancomycin therapeutic targets in these patients. Methods: This retrospective cohort study included patients on ECMO treated with vancomycin between January 2010 and December 2018. Ninety patients were analyzed based on ECMO connection modality, baseline creatinine levels, estimated glomerular filtration rate (eGFR), renal replacement therapy (RRT) requirements, and vancomycin loading dose administration. Results: Twenty-three percent of the patients achieved the therapeutic range defined by baseline levels. No significant differences in meeting the therapeutic goal were found in multivariate analysis considering ECMO cannulation modality, initial creatinine level, initial eGFR, RRT requirement, or loading dose use. All trough levels between 15 and 20 mcg/mL achieved an estimated area under the curve/minimum inhibitory concentration (AUC/MIC) between 400 and 600, almost all trough levels over 10 mcg/mL predicted an AUC/MIC >400. Discussion: Achieving therapeutic plasma levels in these patients remains challenging, potentially due to factors such as individual pharmacokinetics and pathophysiology. A trough plasma level between 12 and 20 estimated the therapeutic AUC/MIC for all models, proposing a possible lower target, maintaining exposure, and potentially avoiding adverse effects. Despite being one of the largest cohorts of vancomycin use in ECMO patients studied, its retrospective nature and single-center focus limits its broad applicability.

Is the time below 90% of SpO2 during sleep (T90%) a metric of good health? A longitudinal analysis of two cohorts.

BACKGROUND: Novel wireless-based technologies can easily record pulse oximetry at home. One of the main parameters that are recorded in sleep studies is the time under 90% of SpO2 (T90%) and the oxygen desaturation index 3% (ODI-3%). We assessed the association of T90% and/or ODI-3% in two different scenarios (a community-based study and a clinical setting) with all-cause mortality (primary outcome). METHODS: We included all individuals from the Sleep Heart Health Study (SHHS, community-based cohort) and Santiago Obstructive Sleep Apnea (SantOSA, clinical cohort) with complete data at baseline and follow-up. Two measures of hypoxemia (T90% and ODI-3%) were our primary exposures. The adjusted hazard ratios (HRs) per standard deviation (pSD) between T90% and incident all-cause mortality (primary outcome) were determined by adjusted Cox regression models. In the secondary analysis, to assess whether T90% varies across clinical factors, anthropometrics, abdominal obesity, metabolic rate, and SpO2, we conducted linear regression models. Incremental changes in R2 were conducted to test the hypothesis. RESULTS: A total of 4323 (56% male, median 64 years old, follow-up: 12 years, 23% events) and 1345 (77% male, median 55 years old, follow-up: 6 years, 11.6% events) patients were included in SHHS and SantOSA, respectively. Every 1 SD increase in T90% was associated with an adjusted HR of 1.18 [95% CI: 1.10-1.26] (p value < 0.001) in SHHS and HR 1.34 [95% CI: 1.04-1.71] (p value = 0.021) for all-cause mortality in SantOSA. Conversely, ODI-3% was not associated with worse outcomes. R2 explains 62% of the variability in T90%. The main contributors were baseline-mean change in SpO2, baseline SpO2, respiratory events, and age. CONCLUSION: The findings suggest that T90% may be an important marker of wellness in clinical and community-based scenarios. Although this nonspecific metric varies across the populations, ventilatory changes during sleep rather than other physiological or comorbidity variables explain their variability.

In situ simulation in the intensive care unit: A phenomenological study of staff experiences.

OBJECTIVE: To explore the experiences of clinical and non-clinical staff in an intensive care unit regarding the perceived benefits and drawbacks of using in situ simulation as a training tool. METHODS: A descriptive phenomenological qualitative study was conducted among clinical and nonclinical ICU personnel. Simulations and interviews were conducted until data saturation was achieved. The interviews were recorded, transcribed verbatim for analysis, and interpreted using the Colaizzi method. RESULTS: Ten participant interviews generated data saturation. ISS was found to be feasible and beneficial in the ICU, facilitating experiential and emotion-based learning in real-world environments. Eight result categories were identified: simulation benefits, simulation benefits in real conditions, scenario authenticity, interference with usual work, ISS sessions, high-fidelity generating affective bonding, ISS as knowledge reinforcement, and recommendations for improvement. The fundamental structure revealed that ISS is perceived as an authentic and emotionally impactful team simulation modality that promotes experiential learning, reflection, and care improvement opportunities within the complex sociotechnical system of the ICU. CONCLUSIONS: All interviewees considered ISS to be a feasible simulation tool that should be implemented in the ICU to improve knowledge and skills, thereby enhancing teamwork.

Adherence to CPAP Treatment and the Risk of Recurrent Cardiovascular Events: A Meta-Analysis.

Importance: The effect of continuous positive airway pressure (CPAP) on secondary cardiovascular disease prevention is highly debated. Objective: To assess the effect of CPAP treatment for obstructive sleep apnea (OSA) on the risk of adverse cardiovascular events in randomized clinical trials. Data Sources: PubMed (MEDLINE), EMBASE, Current Controlled Trials: metaRegister of Controlled Trials, ISRCTN Registry, European Union clinical trials database, CENTRAL (Cochrane Central Register of Controlled Trials), and ClinicalTrials.gov databases were systematically searched through June 22, 2023. Study Selection: For qualitative and individual participant data (IPD) meta-analysis, randomized clinical trials addressing the therapeutic effect of CPAP on cardiovascular outcomes and mortality in adults with cardiovascular disease and OSA were included. Data Extraction and Synthesis: Two reviewers independently screened records, evaluated potentially eligible primary studies in full text, extracted data, and cross-checked errors. IPD were requested from authors of the selected studies (SAVE [NCT00738179], ISAACC [NCT01335087], and RICCADSA [NCT00519597]). Main Outcomes and Measures: One-stage and 2-stage IPD meta-analyses were completed to estimate the effect of CPAP treatment on risk of recurrent major adverse cardiac and cerebrovascular events (MACCEs) using mixed-effect Cox regression models. Additionally, an on-treatment analysis with marginal structural Cox models using inverse probability of treatment weighting was fitted to assess the effect of good adherence to CPAP (≥4 hours per day). Results: A total of 4186 individual participants were evaluated (82.1% men; mean [SD] body mass index, 28.9 [4.5]; mean [SD] age, 61.2 [8.7] years; mean [SD] apnea-hypopnea index, 31.2 [17] events per hour; 71% with hypertension; 50.1% receiving CPAP [mean {SD} adherence, 3.1 {2.4} hours per day]; 49.9% not receiving CPAP [usual care], mean [SD] follow-up, 3.25 [1.8] years). The main outcome was defined as the first MACCE, which was similar for the CPAP and no CPAP groups (hazard ratio, 1.01 [95% CI, 0.87-1.17]). However, an on-treatment analysis by marginal structural model revealed a reduced risk of MACCEs associated with good adherence to CPAP (hazard ratio, 0.69 [95% CI, 0.52-0.92]). Conclusions and Relevance: Adherence to CPAP was associated with a reduced MACCE recurrence risk, suggesting that treatment adherence is a key factor in secondary cardiovascular prevention in patients with OSA.

Hypoxemic features of obstructive sleep apnea and the risk of mortality: a cluster analysis.

INTRODUCTION: Patients with moderate to severe obstructive sleep apnea (OSA) have an increased risk of cardiovascular comorbidities and mortality. Although different subtypes of OSA have been described, data about oximetric parameters and their suitability to identify a different phenotype are scant. In this study, we evaluate the association between moderate to severe OSA and oximetric parameters included in the home sleep apnea test (HSAT) and the risks of all-cause mortality, cardiovascular mortality, and cancer mortality. METHODS: Adult patients with moderate to severe OSA from a clinical cohort in Chile were included (SantOSA study). We developed a latent class analysis (LCA) incorporating oximetric measures commonly reported on HSAT. Differences between the groups were evaluated using ANOVA and the chi-squared test. Survival curves were constructed using a Kaplan-Meier (log-rank) model, and adjusted hazard ratios of mortality were calculated using a Cox regression model following a confounder analysis of cardiovascular comorbidities. RESULTS: A total of 889 patients were included in the analysis. LCA identified three different clusters: Cluster 1, "nonhypoxemic" (n = 591); cluster 2, "moderately hypoxemic" (n = 297); and cluster 3, "severely hypoxemic" (n = 115). The mean follow-up was 4.7 years. The hypoxemic groups showed an increased risk of cardiometabolic comorbidities and an independent risk of all-cause mortality (adjusted HR 1.67 (CI 1.0-2.64) p value = 0.027). The moderately hypoxemic group had an adjusted HR of 2.92 (CI 1.00-8.58), p value = 0.05, while the severely hypoxemic group had an adjusted HR of 2.55 (CI 1.08-6.02), p value = 0.031. For cardiovascular mortality, we found an HR of 2.03 (CI 0.50-8.136), p value = 0.31, and for cancer mortality, we found an HR of 5.75 (CI 1.03-32.17), p value = 0.042. CONCLUSION: Oximetric parameters are useful for describing a different phenotype with a high risk of mortality among patients with moderate to severe OSA, beyond the apnea-hypopnea index.

Risk of mortality among patients with moderate to severe obstructive sleep apnea and diabetes mellitus: results from the SantOSA cohort.

INTRODUCTION: Patients with obstructive sleep apnea (OSA) and comorbid diabetes mellitus (DM) are reported to have an increased risk of cardiovascular (CV) outcomes; however, data on CV mortality are scant. AIM: This study aimed to evaluate if patients with comorbid OSA and DM have an increased risk of CV mortality that is higher than the two diseases in isolation. METHODS: In this prospective cohort study, we included patients referred for a sleep study with and without DM at baseline. We developed four study groups as follows: group 1 (reference group), OSA (-) DM (-); group 2, OSA (-) DM (+); group 3, OSA (+) DM (-); group 4, OSA (+) DM (+). Intergroup differences were evaluated using the t test and χ2 test, and multivariate analysis was performed using logistic regression. The incidence rates of CV mortality were calculated using the Kaplan-Meier (log-rank) model, and adjusted HRs were calculated using the Cox regression model. RESULTS: A total of 1447 patients were included in the analysis-group 1: 441 participants; group 2: 141 participants; group 3: 736 participants; group 4: 151 participants. The mean follow-up was 5 years. The association between OSA + DM showed an independent risk of incident CV mortality (HR 2.37, CI 1.16-4.82, p = 0.02) and an increased prevalence of coronary heart disease (OR 3.44, CI 1.73-5.59, p < 0.01). In addition, T90% was also associated with CV mortality. CONCLUSION: The coexistence of OSA + DM was associated with an independent risk of CV mortality. In addition, T90% was also associated with CV mortality.

Chronic intermittent hypoxia in obstructive sleep apnea: a narrative review from pathophysiological pathways to a precision clinical approach.

Obstructive sleep apnea syndrome (OSAS) is a prevalent condition caused by dynamic upper airway collapse during sleep. The pathological impact and consequences are due to chronic intermittent hypoxia (CIH). Hypoxia increases the expression of several inflammatory stress markers and endothelial dysfunction. Recent studies suggest that patients with a similar AHI but with severe nocturnal hypoxia using oximetric parameters, such as the lowest saturation of oxygen during the night (min SaO2), percentage of total sleep time with oxygen saturation < 90% (T90) or the oxygen desaturation index (ODI-3%), commonly reported during the sleep study, are indicative of the increased expression of inflammatory markers due to severe nocturnal hypoxia and CIH during the night compared to subjects with moderate-severe OSAS without severe nocturnal hypoxia. The aim of this review is to describe physiological pathways involved in OSAS and their clinical consequences, focused in CIH and oximetric parameters showed in sleep study and their potential utility as inflammatory markers.

Do T90 and SaO2 nadir identify a different phenotype in obstructive sleep apnea?

INTRODUCTION: Severity of obstructive sleep apnea (OSA) is commonly based upon the apnea-hypopnea index (AHI). However, patients with similar AHIs may demonstrate widely varying comorbidities and risk for cardiovascular disease. These varying manifestations of disease may be related to nocturnal hypoxia and not AHI. We hypothesize that parameters of oxygenation may identify a different phenotype in OSA. PURPOSE: To explore potential associations between lowest SaO2 (SaO2 nadir) and total sleep time spent with arterial oxygen saturation (SaO2) < 90% (T90) with comorbidities and mortality in patients with moderate and severe OSA. METHOD: This was a retrospective study of patients between 2009 and 2014, with a new diagnosis of moderate-to-severe OSA without a concomitant respiratory disease. Data collection included demography, comorbidities, sleep study parameters, and mortality over a 5-year interval. Patients were categorized into two groups for analysis, group 1: SaO2 nadir < 75%, and group 2: T90 > 20%. RESULTS: Of the 365 patients, 163 (45%) recorded SaO2 nadir < 75% and 127 (35%) recorded T90 > 20%. These oxygenation parameters were associated with more severe OSA by AHI (p < 0.001). T90 > 20% was associated with an increased risk of hypertension (HT) OR 2.95 (CI 1.87-4.76, p < 0.001) in patients with both moderate and severe OSA. T90 > 20% was also associated with an increased risk of type 2 diabetes mellitus (T2DM) OR 2.14 (CI 1.35-3.38, p = 0.001) and mortality 2.70 (CI 1.37-5.22, p = 0.0048). CONCLUSION: The findings demonstrate a correlation between SaO2 nadir < 75% and T90 > 20% and increased severity of OSA. The findings also show a strong association between SaO2 nadir < 75% and T90 > 20% and increased risk for comorbidities of HT and T2DM as well as mortality at 5 years. This analysis suggests that parameters of oxygenation should be used to describe a high-risk phenotype of OSA.

[Acute pulmonary fibrosis associated with Paraquat poisoning. Report of one case]. / Fibrosis pulmonar aguda asociada a intoxicación por Paraquat: caso clínico.

Paraquat, a non-selective bipyridyl pesticide, is one of the leading causes of death from intoxication in many parts of Asia and America. It is the second most sold herbicide worldwide, being widely used in Chile. Its ingestion generates toxicity due to the release of superoxide radicals, mainly affecting kidneys, lungs and liver. There is no antidote available. We report a 31 years old male who ingested Paraquat for suicidal purposes. He developed an acute renal and hepatic failure and a rapidly progressive severe respiratory failure with images compatible with acute pulmonary fibrosis. No response to immunosuppressive treatment was observed. He died eight days after admission. The use of cyclophosphamide associated with glucocorticoids could lower risk of death the in these patients, although the pathophysiology of respiratory failure is still under study.

Leptospirosis-associated catastrophic respiratory failure supported by extracorporeal membrane oxygenation.

A previously healthy, 39-year-old obese farmer, arrived hypotensive and tachycardic, with fever, myalgia, headache, abdominal pain, diarrhea, and progressive dyspnea. Ten days before symptoms onset, he was in direct contact with mice and working in a contaminated drain. Patient laboratory showed acute kidney injury and thrombocytopenia. Chest X-ray exhibited bilateral diffuse interstitial infiltrates. First-line empirical antibiotics were started and influenza discarded. Patient evolved with severe respiratory failure, associated with hemoptysis, and rapidly severe hemodynamic compromise. Despite neuromuscular blockade and prone positioning, respiratory failure increased. Accordingly, veno-venous ECMO was initiated, with bilateral femoral extraction and jugular return. After ECMO connection, there was no significant improvement in oxygenation, and low pre-membrane saturations and low arterial PaO2 of the membrane showed that we were out of the limits of the rated flow. Thus, a second membrane oxygenator was installed in parallel. Afterward, oxygenation improved, with subsequent perfusion enhancement. Regarding etiology, due to high suspicion index, Leptospira serology was performed, coming back positive and meropenem was maintained. The patient ultimately recovered and experience excellent outcome. The clinical relevance of the case is the scared evidence of leptospirosis-associated severe respiratory failure treated with ECMO. This experience emphasizes the importance of an optimal support, which requires enough membrane surface and flow for an obese, highly hyperdynamic patient, during this reversible disease. A high index of suspicion is needed for an adequate diagnosis of leptospirosis to implement the correct treatment, particularly in the association of respiratory failure, pulmonary hemorrhage, and an epidemiological-related context.

[Metformin-associated lactic acidosis. Report of one case]. / Acidosis láctica asociada a metformina. Caso clínico.

Metformin-associated lactic acidosis is a severe and infrequent adverse event. Early diagnosis is essential to start an early treatment, which often has favorable results. We report a 56 years old non-insulin-requiring type 2 diabetic female who developed a severe metabolic acidosis associated with metformin in relation to an acute renal failure secondary to infectious diarrhea. Early treatment with bicarbonate and continuous hemofiltration allowed a quick improvement of the patient. Metformin-associated lactic acidosis has an elevated mortality (50-80%) and has a specific and effective treatment. Therefore, the condition must be born in mind.

Severe osmotic demyelination syndrome with cortical involvement in the context of severe hyponatremia and central diabetes insipidus: an uncommon presentation of an unusual combination.

BACKGROUND: Osmotic demyelination syndrome (ODS) with cerebral cortical involvement is a rare complication of severe hyponatremia correction. Careful management of hyponatremia is crucial, particularly in patients with risk factors, such as alcohol use disorder and diabetes insipidus. CASE: A patient in his 40s with a history of alcohol use disorder and central diabetes insipidus developed ODS after a 24 mEq/L osmolar increase during the treatment of hyponatremia. The patient's condition progressed into locked-in syndrome and then improved to spastic tetraparesis after cortical basal ganglia ODS improved. DISCUSSION: The differential diagnosis of cortical demyelination includes laminar cortical necrosis, being the interpretation of Apparent Diffusion Coefficient (ADC) MRI sequence is a useful tool.This case underscores the need to investigate and improve diagnosis and treatment strategies in patients with ODS. It also emphasises the significance of careful hyponatremia correction and frequent monitoring, particularly in patients with known risk factors for ODS.

Rate of severe exacerbations, healthcare resource utilisation and clinical outcomes in patients with COPD in low-income and middle-income countries: results from the EXACOS International Study.

INTRODUCTION: The EXAcerbations of Chronic obstructive lung disease (COPD) and their OutcomeS (EXACOS) International Study aimed to quantify the rate of severe exacerbations and examine healthcare resource utilisation (HCRU) and clinical outcomes in patients with COPD from low-income and middle-income countries. METHODS: EXACOS International was an observational, cross-sectional study with retrospective data collection from medical records for a period of up to 5 years. Data were collected from 12 countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Dominican Republic, Guatemala, Hong Kong, Mexico, Panama, Russia and Taiwan. The study population comprised patients ≥40 years of age with COPD. Outcomes/variables included the prevalence of severe exacerbations, the annual rate of severe exacerbations and time between severe exacerbations; change in lung function over time (measured by the forced expiratory volume in 1 s (FEV1)); peripheral blood eosinophil counts (BECs) and the prevalence of comorbidities; treatment patterns; and HCRU. RESULTS: In total, 1702 patients were included in the study. The study population had a mean age of 69.7 years, with 69.4% males, and a mean body mass index of 26.4 kg/m2. The mean annual prevalence of severe exacerbations was 20.1%, and 48.4% of patients experienced ≥1 severe exacerbation during the 5-year study period. As the number of severe exacerbations increased, the interval between successive exacerbations decreased. A statistically significant decrease in mean (SD) FEV1 from baseline to post-baseline was observed in patients with ≥1 severe exacerbation (1.23 (0.51) to 1.13 (0.52) L; p=0.0000). Mean BEC was 0.198 x109 cells/L, with 64.7% of patients having a BEC ≥0.1 x109 cells/L and 21.3% having a BEC ≥0.3 x109 cells/L. The most common comorbidity was hypertension (58.3%). An increasing number of severe exacerbations per year was associated with greater HCRU. DISCUSSION: The findings presented here indicate that effective treatment strategies to prevent severe exacerbations in patients with COPD remain a significant unmet need in low-income and middle-income countries.

Clinical Concepts for Triple Therapy Use in Patients with COPD: A Delphi Consensus.

Purpose: Role of triple therapy in chronic obstructive pulmonary disease (COPD) management is supported by growing evidence, but consensus is lacking on various aspects. We conducted a Delphi survey in respiratory experts on the effects of triple therapy on exacerbation reduction, early optimization, pneumonia risk, and mortality benefits in COPD management. Methods: The study comprised 2-round online surveys and a participant meeting with 21 respiratory experts from 10 countries. The 31-statement questionnaire was prepared using Decipher software after literature review. Responses were recorded using Likert scale ranging from 1 (disagreement) to 9 (agreement) with a consensus threshold of 75%. Results: All experts participated in both surveys and 14/21 attended participant meeting. Consensus was reached on 13/31 questions in first survey and 4/14 in second survey on: mortality benefits of triple therapy; comparable pneumonia risk between single inhaler triple therapy (SITT) and multiple inhaler triple therapy (81%); preference of SITT for patients with high eosinophil count (95%); exacerbation risk reduction and healthcare cost benefits with early initiation of SITT post exacerbation-related hospitalization (<30 days) (86%). No consensus was reached on first line SITT use after first exacerbation resulting in COPD diagnosis (62%). Conclusion: This study demonstrated that there is consensus among experts regarding many of the key concepts about appropriate clinical use and benefits of triple therapy in COPD. More evidence is required for evaluating the benefits of early optimisation of triple therapy.

The U-Shaped Association between Sleep Duration, All-Cause Mortality and Cardiovascular Risk in a Hispanic/Latino Clinically Based Cohort.

Sleep is essential for life, and inappropriate sleep duration patterns may lead to chronic consequences regarding human health. Several studies have confirmed the presence of a U-shaped association between sleep duration and mortality. Moreover, many consequences related to cardiometabolic aspects have been suggested in patients with abnormal sleep durations. In this study, we analyzed the associations between sleep duration, total sleep time (TST), the risk of all-cause mortality, and 10-year cardiovascular risk in a cohort of patients at a sleep medicine center in Santiago, Chile. We conducted a prospective cohort study of patients (SantOSA). A short TST was defined as ≤6 h, a normal TST as 6 to 9 h, and a long TST as ≥9 h. Adjusted hazard ratios (aHRs) for all-cause mortality were calculated. A cross-sectional analysis between TST and 10-year cardiovascular risk (calculated using the Framingham 2008 formula) was determined using logistic regression models. A total of 1385 subjects were included in the results (78% male; median age: 53, interquartile range (IQR): 42-64 years; median BMI: 29.5, IQR: 16.7-33.1). A total of 333 subjects (24%) reported short TSTs, 938 (67.7%) reported normal TSTs, and 114 (8.3%) reported long TSTs. In the fully adjusted model, the association remained significant for short (aHR: 2.51 (1.48-4.25); p-value = 0.01) and long TSTs (aHR: 3.97 (1.53-10.29); p-value = 0.04). Finally, a U-shaped association was found between short and long TSTs, with an increase in cardiovascular risk at 10 years. Compared with normal TSTs, short (≤6 h) and long (≥9 h) TSTs were significantly associated with all-cause mortality and increased 10-year cardiovascular risk.

Effects of changes in trunk inclination on ventilatory efficiency in ARDS patients: quasi-experimental study.

BACKGROUND: Trunk inclination from semirecumbent head-upright to supine-flat positioning reduces driving pressure and increases respiratory system compliance in patients with acute respiratory distress syndrome (ARDS). These effects are associated with an improved ventilatory ratio and reduction in the partial pressure of carbon dioxide (PaCO2). However, these physiological effects have not been completely studied, and their mechanisms have not yet been elucidated. Therefore, this study aimed to evaluate the effects of a change in trunk inclination from semirecumbent (45°) to supine-flat (10°) on physiological dead space and ventilation distribution in different lung regions. RESULTS: Twenty-two ARDS patients on pressure-controlled ventilation underwent three 60-min steps in which trunk inclination was changed from 45° (baseline) to 10° (intervention) and back to 45° (control) in the last step. Tunk inclination from a semirecumbent (45°) to a supine-flat (10°) position resulted in a higher tidal volume [371 (± 76) vs. 433 (± 84) mL (P < 0.001)] and respiratory system compliance [34 (± 10) to 41 (± 12) mL/cmH2O (P < 0.001)]. The CO2 exhaled per minute improved from 191 mL/min (± 34) to 227 mL/min (± 38) (P < 0.001). Accordingly, Bohr's dead space ratio decreased from 0.49 (± 0.07) to 0.41 (± 0.06) (p < 0.001), and PaCO2 decreased from 43 (± 5) to 36 (± 4) mmHg (p < 0.001). In addition, the impedance ratio, which divides the ventilation activity of the ventral region by the dorsal region ventilation activity in tidal images, dropped from 1.27 (0.83-1.78) to 0.86 (0.51-1.33) (p < 0.001). These results, calculated from functional EIT images, indicated further ventilation activity in the dorsal lung regions. These effects rapidly reversed once the patient was repositioned at 45°. CONCLUSIONS: A change in trunk inclination from a semirecumbent (45 degrees) to a supine-flat position (10 degrees) improved Bohr's dead space ratio and reduced PaCO2 in patients with ARDS. This effect is associated with an increase in tidal volume and respiratory system compliance, along with further favourable impedance ventilation distribution toward the dorsal lung regions. This study highlights the importance of considering trunk inclination as a modifiable determinant of physiological parameters. The angle of trunk inclination is essential information that must be reported in ARDS patients.

Clinical Application of the Multicomponent Grading System for Sleep Apnea Classification and Incident Cardiovascular Mortality.

Objective To evaluate the clinical utility of the Baveno classification in predicting incident cardiovascular mortality after five years of follow-up in a clinic-based cohort of patients with obstructive sleep apnea (OSA). Materials and Methods We evaluated the reproducibility of the Baveno classification using data from the Santiago Obstructive Sleep Apnea (SantOSA) study. The groups were labeled Baveno A (minor symptoms and comorbidities), B (severe symptoms and minor comorbidities), C (minor symptoms and severe comorbidities), and D (severe symptoms and comorbidities). Within-group comparisons were performed using analysis of variance (ANOVA) and post hoc tests. The associations between groups and incident cardiovascular mortality were determined through the Mantel-Cox and Cox proportional hazard ratios (HRs) adjusted by covariables. Results A total of 1,300 OSA patients were included (Baveno A: 27.7%; B: 28%; C: 16.8%; and D: 27.5%). The follow-up was of 5.4 years. Compared to Baveno A, the fully-adjusted risk of cardiovascular mortality with Baveno B presented an HR of 1.38 (95% confidence interval [95%CI]: 0.14-13.5; p = 0.78); with Baveno C, it was of 1.71 (95%CI: 0.18-16.2; p = 0.63); and, with Baveno D, of 1.04 (95%CI: 0.12-9.2; p = 0.98). We found no interactions involving Baveno group, sex and OSA severity. Discussion Among OSA patients, the Baveno classification can describe different subgroups. However, its utility in identifying incident cardiovascular mortality is unclear. Long-term follow-up studies and the inclusion of demographic variables in the classification could improve its ability to detect a high-risk phenotype associated with cardiovascular mortality. Conclusion The Baveno classification serves as a valuable method for categorizing varying groups of patients afflicted with OSA. Nevertheless, its precision in identifying occurrence of cardiovascular mortality is still unclear.

Undiagnosed sleep disorder breathing as a risk factor for critical COVID-19 and pulmonary consequences at the midterm follow-up.

INTRODUCTION: Patients with severe COVID-19 develops an acute respiratory distress syndrome (ARDS), requiring admission to the intensive care unit. COVID-19 also reports an increased prevalence of comorbidities, similar to patients with Sleep disorder breathing (SDB). OBJECTIVES: To evaluate the association between undiagnosed SDB and the risk of ARDS and pulmonary abnormalities in a cohort of patients' survivors of COVID-19 between 3 and 6 months after diagnosis. METHODS: Prospective cohort study of patients who developed ARDS during hospitalization due to COVID-19 compared with a control group of patients who had COVID-19 with mild to moderate symptoms. All patients were evaluated between the 12th and 24th week after SARS-CoV-2 infection. The evaluation includes persistent symptoms, lung diffusing capacity of carbon monoxide (DLCO), chest CT scan and home sleep apnea test. SDB was diagnosed by the respiratory disturbance index ≥5 ev/h. The association between SDB and ARDS, the hazards of lung impairment and the hazard ratios (HR) were analyzed. RESULTS: A total of 60 patients were included (ARDS: 34 patients, Control: 26 patients). The mean follow-up was 16 weeks (range 12-24). ARDS reported a high prevalence of SDB (79% vs. 38% in control group). A total of 35% reported DLCO impairment, and 67.6% abnormal chest CT. SDB was independently associated to ARDS, OR 6.72 (CI, 1.56-28.93), p < 0.01, and abnormal Chest CT, HR 17.2 (CI, 1.68-177.4, p = 0.01). Besides, ARDS, days in mechanical ventilation, male gender were also associated with an increased risk of abnormal chest CT. CONCLUSION: Undiagnosed SDB is prevalent and independently associated with ARDS. In addition, undiagnosed SDB increased the hazard of abnormal Chest CT in the midterm. STUDY REGISTER: ISRCTN16865246.

Telemedicine interventions for CPAP adherence in obstructive sleep apnea patients: Systematic review and meta-analysis.

Continuous positive airway pressure (CPAP) is the preferred therapy in patients with obstructive sleep apnea (OSA). However, data suggests treatment adherence is low. In recent years, telemedicine-based intervention (TM) has been evaluated to increase adherence. In this systematic review and meta-analysis of randomized controlled trials (RCTs), we evaluated the efficacy of TM on CPAP adherence in patients with OSA. Two independent reviewers explored five databases; the risk of bias (RoB) was evaluated using the Cochrane tool. Outcomes were defined as the mean difference (MD) in CPAP use per night and the proportion of patients with increased CPAP adherence of ≥4 h/night. The meta-analysis was conducted following the DerSimonian-Laird method, and the certainty of the evidence was rated according to GRADE. We included 16 RCTs including 3039 participants. The RoB was low in 12/16 studies. TM was associated with an increase in CPAP adherence of 29.2 min/night, I2 =75% (p < 0.01), and CPAP adherence ≧4 h/night, RR: 1.09 (1.02-1.17), I2 =22%. Subgroup analyses reported better results between three and 6 months, in the sleepy subgroup. Finally, based on the results obtained in this systematic review, there is favorable evidence regarding the treatment with TM in patients with OSA using CPAP. REVIEW REGISTRATION NUMBER: CRD42020165367.