Obstructive sleep apnea and acute respiratory failure: An analysis of mortality risk in patients with pneumonia requiring invasive mechanical ventilation

Outcomes of coronary artery bypass grafting (CABG) in patients with OSA-COPD overlap syndrome versus COPD alone: an analysis of US Nationwide Inpatient Sample

BACKGROUND

Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are associated with unfavorable outcomes following coronary artery bypass grafting (CABG). The purpose of this study was to compare in-hospital outcomes of patients with COPD alone versus OSA-COPD overlap after CABG.

METHODS

Data of adults ≥ 18 years old with COPD who received elective CABG between 2005 and 2018 were extracted from the US Nationwide Inpatient Sample (NIS). Patients were divided into two groups: with OSA-COPD overlap and COPD alone. Propensity score matching (PSM) was employed to balance the between-group characteristics. Logistic and linear regression analyses determined the associations between study variables and inpatient outcomes.

RESULTS

After PSM, data of 2,439 patients with OSA-COPD overlap and 9,756 with COPD alone were analyzed. After adjustment, OSA-COPD overlap was associated with a significantly increased risk of overall postoperative complications (adjusted odd ratio [aOR] = 1.12, 95% confidence interval [CI]: 95% CI: 1.01-1.24), respiratory failure/prolonged mechanical ventilation (aOR = 1.27, 95%CI: 1.14-1.41), and non-routine discharge (aOR = 1.16, 95%CI: 1.03-1.29), and AKI (aOR = 1.14, 95% CI: 1.00-1.29). Patients with OSA-COPD overlap had a lower risk of in-hospital mortality (adjusted odd ratio [aOR] = 0.53, 95% CI: 0.35-0.81) than those with COPD only. Pneumonia or postoperative atrial fibrillation (AF) risks were not significantly different between the 2 groups. Stratified analyses revealed that, compared to COPD alone, OSA-COPD overlap was associated with increased respiratory failure/prolonged mechanical ventilation risks among patients ≥ 60 years, and both obese and non-obese subgroups. In addition, OSA-COPD overlap was associated with increased risk of AKI among the older and obese subgroups.

CONCLUSION

In US adults who undergo CABG, compared to COPD alone, those with OSA-COPD are at higher risks of non-routine discharge, AKI, and respiratory failure/prolonged mechanical ventilation, but a lower in-hospital mortality. No increased risk of AF was noted.

OSA and Subsequent Risk of Hospitalization With Pneumonia, Respiratory Infection, and Total Infection: The Atherosclerosis Risk in Communities Study

BACKGROUND

OSA has been linked to microaspiration, systemic inflammation, and suboptimal immune function.

RESEARCH QUESTION

Is OSA prospectively associated with risk of hospitalization for pneumonia, respiratory, and total infections?

STUDY DESIGN AND METHODS

Prospective cohort. Participants in the Atherosclerosis Risk in Communities (ARIC) study (N = 1,586) underwent polysomnography in 1996-1998 and were followed up through 2018 for infection-related hospitalizations. The apnea-hypopnea index (AHI; events/h) was used to categorize participants as having severe OSA (≥ 30), moderate OSA (15-29), mild OSA (5-14), or a normal breathing pattern (< 5). Cox regression was used to calculate hazard ratios (HRs) and 95% CIs.

RESULTS

ARIC participants were on average 62.7 (SD = 5.5) years of age, and 52.8% were female. Severe OSA was present in 6.0%, moderate OSA in 12.7%, mild OSA in 30.0%, and normal breathing in 51.3%. A total of 253 hospitalizations with pneumonia occurred over a median 20.4 (max, 22.9) years' follow-up. Participants with severe OSA were at 1.87 times (95% CI, 1.19-2.95) higher risk of hospitalization with pneumonia compared with those with a normal breathing pattern after adjustment for demographics and lifestyle behaviors. Results were attenuated modestly after adjustment for BMI (1.62 [0.99-2.63]), and prevalent asthma and COPD (1.62 [0.99-2.63]). A similar pattern existed for hospitalization with respiratory infection and composite infection (demographic and behavior-adjusted HRs: 1.47 [0.96-2.25] and 1.48 [1.07-2.04], respectively).

INTERPRETATION

Severe OSA was associated with increased risk of hospitalizations with pneumonia in this community-based cohort. OSA patients may benefit from more aggressive efforts to prevent pneumonia and other infectious conditions.

Sex-differences in the effect of obstructive sleep apnea on patients hospitalized with pulmonary embolism and on in-hospital mortality

We determined sex differences in the prevalence of obstructive sleep apnea (OSA) among patients hospitalized with pulmonary embolism (PE) in Spain (2016–2018). We also compared outcomes according to the presence of OSA, and identified variables associated with in-hospital-mortality (IHM) after PE using the Spanish National Hospital Discharge Database. We identified 46,794 hospital admissions for PE; of these, 5.47% had OSA. OSA was more prevalent among men than women (7.57% vs. 3.65%, p < 0.001), as in the general population. Propensity score matching did not reveal differences in concomitant conditions or procedures between patients with and without OSA, except for the use of non-invasive ventilation, which was more frequent in patients with OSA. IHM was similar in patients with and without OSA (3.58% vs. 4.31% for men and 4.39% vs. 4.93% for women; p > 0.05). Older age, cancer, atrial fibrillation, non-septic shock, and need for mechanical ventilation increased IHM in men and women with OSA hospitalized with PE. The logistic regression model showed no sex differences in IHM among patients with OSA.

The Impact of Obstructive Sleep Apnea on the Sleep of Critically Ill Patients

Obstructive sleep apnea is becoming increasingly prevalent in society and thus critical care practitioners need to be prepared to care for these patients in the intensive care unit. Preparation begins with equipping the critical care nurse with the knowledge necessary to provide interventions which can enhance patient outcomes and mitigate complications.

Remote ischemic conditioning for acute respiratory distress syndrome in COVID-19

Acute respiratory distress syndrome and subsequent respiratory failure remains the leading cause of death (>80%) in patients severely impacted by COVID-19. The lack of clinically effective therapies for COVID-19 calls for the consideration of novel adjunct therapeutic approaches. Though novel antiviral treatments and vaccination hold promise in control and prevention of early disease, it is noteworthy that in severe cases of COVID-19, addressing "run-away" inflammatory cascades are likely more relevant for improvement of clinical outcomes. Viral loads may decrease in severe, end-stage coronavirus cases, but a systemically damaging cytokine storm persists and mediates multiple organ injury. Remote ischemic conditioning (RIC) of the limbs has shown potential in recent years to protect the lungs and other organs against pathological conditions similar to that observed in COVID-19. We review the efficacy of RIC in protecting the lungs against acute injury and current points of consideration. The beneficial effects of RIC on lung injury along with other related cardiovascular complications are discussed, as are the limitations presented by sex and aging. This adjunct therapy is highly feasible, noninvasive, and proven to be safe in clinical conditions. If proven effective in clinical trials for acute respiratory distress syndrome and COVID-19, application in the clinical setting could be immediately implemented to improve outcomes.

Postextubation respiratory events in patients admitted to the intensive care unit: a prospective pilot study using overnight respiratory polygraphy

Background

Before the main trial in which respiratory polygraphy will be used to evaluate postextubation sleep apnea in critically ill patients, we performed a prospective pilot study to ensure that any issues with the conduct of the trial would be identified.

Methods

In the present study, 13 adult patients who had received mechanical ventilation for ≥24 hours were prospectively recruited. Among the patients, 10 successfully completed respiratory polygraphy on the first or second night after extubation. Data regarding the types and doses of corticosteroids, analgesics, sedatives, and muscle relaxants as well as the methods of oxygen delivery were recorded.

Results

During the night of respiratory polygraphy, all 10 patients received supplemental oxygen (low-flow oxygen, n=5; high-flow oxygen, n=5), and seven patients received intravenous corticosteroids. Three of the 10 patients had a respiratory event index (REI) ≥5/hr. All respiratory events were obstructive episodes. None of the patients receiving high-flow oxygen therapy had an REI ≥5/hr. Two of the seven patients who received corticosteroids and one of the other three patients who did not receive this medication had an REI ≥5/hr. Although low- or high-flow oxygen therapy was provided, all patients had episodes of oxygen saturation (SpO₂) <90%. Two of the three patients with an REI ≥5/hr underwent in-laboratory polysomnography. The patients’ Apnea-Hypopnea Index and REI obtained via polysomnography and respiratory polygraphy, respectively, were similar.

Conclusions

In a future trial to evaluate postextubation sleep apnea in critically ill patients, pre-stratification based on the use of corticosteroids and high-flow oxygen therapy should be considered.

Impact of obstructive sleep apnea on the obesity paradox in critically ill patients

OBJECTIVE

Patients admitted to an intensive care unit (ICU) frequently suffer from multiple chronic diseases, including obstructive sleep apnea (OSA). Until recently OSA was not considered as a key determinant in an ICU patient's prognosis. The objective of this study was to document the impact of OSA on the prognosis of ICU patients.

METHODS

Data were retrospectively collected concerning adult patients admitted to ICU at two university hospitals. In a nested study OSA status was checked using the hospital electronic medical records to identify exposed and unexposed cases. The following outcomes were considered: length of stay in the ICU, ICU mortality, in-hospital mortality, ventilator-associated pneumonia (VAP).

RESULTS

Out of 5146 patients included in the study, 289 had OSA at ICU admission (5.6%). After matching, the overall impact of OSA on length of ICU stay was not significant (p = .24). In a predefined subgroup analysis, there was a significant impact of OSA on the length of ICU stay for patients with BMI over 40 kg/m² (IRR: 1.56 [1.05; 2.32], p = .03). OSA status had no impact on ICU or hospital mortality and VAP.

CONCLUSION

In general, known OSA did not increase the ICU stay except for patients with both OSA and morbid obesity.

Impact of Intermittent Hypoxia on Sepsis Outcomes in a Murine Model

Sleep apnea has been associated with a variety of diseases, but its impact on sepsis outcome remains unclear. This study investigated the effect of intermittent hypoxia [IH]–the principal feature of sleep apnea–on murine sepsis. 5-week-old male C57BL6 mice were assigned to groups receiving severe IH (O2 fluctuating from room air to an O2 nadir of 5.7% with a cycle length of 90 seconds), mild IH (room air to 12%, 4 minutes/cycle), or room air for 3 weeks. Sepsis was induced by cecal ligation and puncture and survival was monitored. Sepsis severity was evaluated by murine sepsis scores, blood bacterial load, plasma tumor necrosis factor-α [TNF-α]/interleukin-6 [IL-6] levels and histopathology of vital organs. Compared with normoxic controls, mice subjected to severe IH had earlier mortality, a lower leukocyte count, higher blood bacterial load, higher plasma TNF-α and IL-6 levels, more severe inflammatory changes in the lung, spleen and small intestine. Mice subjected to mild IH did not differ from normoxic controls, except a higher IL-6 level after sepsis induced. The adverse impact of severe IH was reversed following a 10-day normoxic recovery. In conclusion, severe IH, not mild IH, contributed to poorer outcomes in a murine sepsis model.

Complications associated with surgical treatment of sleep-disordered breathing among hospitalized U.S. adults

The purpose of this cross-sectional study is to examine the relationship between surgical treatments for sleep-disordered breathing (SDB) and composite measure of surgical complications in a nationally representative sample of hospital discharges among U.S. adults. We performed secondary analyses of 33,679 hospital discharges from the 2002-2012 Nationwide Inpatient Sample that corresponded to U.S. adults (≥18 years) who were free of head-and-neck neoplasms, were diagnosed with SDB and had undergone at least one of seven procedures. Multivariate logistic regression models were constructed to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI), controlling for age, sex, race/ethnicity, obstructive sleep apnea (OSA) and obesity diagnoses. Positive associations were found between composite measure of surgical complications and specific procedures: palatal procedure (aOR = 12.69, 95% CI: 11.91,13.53), nasal surgery (aOR = 6.47, 95% CI: 5.99,6.99), transoral robotic assist (aOR = 5.06, 95% CI: 4.34-5.88), tongue base/hypopharynx (aOR = 4.24, 95% CI: 3.88,4.62), maxillomandibular advancement (MMA) (aOR = 3.24, 95% CI: 2.74,3.84), supraglottoplasty (aOR = 2.75, 95% CI: 1.81,4.19). By contrast, a negative association was found between composite measures of surgical complications and tracheostomy (aOR = 0.033, 95% CI: 0.031,0.035). In conclusion, most procedures for SDB, except tracheostomy, were positively associated with complications, whereby palatal procedures exhibited the strongest and supraglottoplasty exhibited the weakest association.

Are sleep disorders associated with increased mortality in asthma patients?

BACKGROUND

South Korea has experienced problems regarding poor management of symptoms of asthma patients and remarkable increases in sleep disorders. However, few studies have investigated these issues. We examined the relationship between sleep disorders and mortality in asthma patients to suggest effective alternatives from a novel perspective.

METHODS

We used data from the National Health Insurance Service (NHIS) National Sample Cohort 2004-2013, which included medical claims filed for 186,491 patients who were newly diagnosed with asthma during the study period. We performed survival analyses using a Cox proportional hazards model with time-dependent covariates to examine the relationship between sleep disorders and mortality in asthma patients.

RESULTS

There were 5179 (2.78%) patients who died during the study period. Sleep disorders in patients previously diagnosed with asthma were associated with a higher risk of mortality (hazard ratio [HR]: 1.451, 95% confidence interval [CI]: 1.253-1.681). In addition, significant interaction was found between sleep disorders and Charlson comorbidity index.

CONCLUSIONS

Our findings suggest that an increased prevalence of sleep disorders in asthma patients increases the risk of mortality. Considering the worsening status of asthma management and the rapid growth of sleep disorders in South Korea, clinicians and health policymakers should work to develop interventions to address these issues.

Efficacy and safety of noninvasive ventilation in patients after cardiothoracic surgery: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Noninvasive ventilation (NIV) is a promising therapeutic strategy after cardiothoracic surgery. This study aimed to meta-analyze the efficacy and safety of NIV as compared to conventional management after cardiothoracic surgery.

METHODS

PubMed, EMBASE, and Cochrane Library databases were searched for randomized controlled trials (RCTs) comparing NIV with conventional management after cardiothoracic surgery. Relative risk (RR), standard mean difference (SMD), and 95% confidence intervals (CIs) were used to measure the efficacy and safety of NIV using random-effects model. Heterogeneity was evaluated using the Q statistic.

RESULTS

This study included 14 RCTs (1740 patients) for the evaluation of efficacy and safety of NIV as compared to conventional management after cardiothoracic surgery. Overall, NIV had minimal effect on the risk of mortality (RR: 0.64; 95% CI: 0.36-1.14; P = 0.127), endotracheal intubation (RR: 0.52; 95% CI: 0.24-1.11; P = 0.090), respiratory (RR: 0.70; 95% CI: 0.47-1.30; P = 0.340), cardiovascular (RR: 0.81; 95% CI: 0.54-1.22; P = 0.306), renal (RR: 0.70; 95% CI: 0.26-1.92; P = 0.491), and other complications (RR: 0.72; 95% CI: 0.38-1.36; P = 0.305), respiratory rate (SMD: -0.10; 95% CI: -1.21-1.01; P = 0.862), heart rate (SMD: -0.27; 95% CI: -0.76-0.22; P = 0.288), PaO2/FiO2 ratio (SMD: 0.34; 95% CI: -0.17-0.85; P = 0.194), PaCO2 (SMD: 0.83; 95% CI: -0.12-1.77; P = 0.087), systolic pressure (SMD: -0.04; 95% CI: -0.25-0.17; P = 0.700), pH (SMD: -0.01; 95% CI: -0.44-0.43; P = 0.974), length of ICU stay (SMD: -0.19; 95% CI: -0.47-0.08; P = 0.171), and hospital stay (SMD: -0.31; 95% CI: -1.00-0.38; P = 0.373). Sensitivity analysis showed that NIV was associated with higher levels of PaO2/FiO2 ratio (SMD: 0.52; 95% CI: 0.00-1.05; P = 0.048) and lower risk of endotracheal intubation (RR: 0.38; 95% CI: 0.22-0.66; P = 0.001).

CONCLUSION

As compared to conventional management, the use of NIV after cardiothoracic surgery improved patient's oxygenation and decreased the need for endotracheal intubation, without significant complications.

Hospitalized Patients at High Risk for Obstructive Sleep Apnea Have More Rapid Response System Events and Intervention Is Associated with Reduced Events

Background

Rapid response system (RRS) is a safety tool designed for early detection and intervention of a deteriorating patient on the general floor in the hospital. Obstructive sleep apnea (OSA) has been associated with significant cardiovascular complications. We hypothesized that patients with high-risk of OSA have higher rate of RRS events and intervention with positive airway pressure therapy in these patients can mitigate the RRS events.

Methods

As part of a clinical pathway, during a 15 month period, patients with BMI ≥ 30 kg/m² in select medical services were screened with a validated sleep questionnaire. Patients were characterized as high or low risk based on the screening questionnaire. RRS rates were compared between the groups. Subsequently the impact of PAP therapy on RRS events was evaluated.

Results

Out of the 2,590 patients screened, 1,973 (76%) were identified as high-risk. RRS rates calculated per 1,000 admissions, were 43.60 in the High-Risk OSA group versus 25.91 in the Low-Risk OSA Group. The PAP therapy compliant group had significantly reduced RRS event rates compared to non-compliant group and group with no PAP therapy (16.99 vs. 53.40 vs. 56.21) (p < 0.01).

Conclusion

In a large cohort of patients at a tertiary care hospital, we show an association of increased rate of RRS events in high-risk OSA patients and reduction of the risk with PAP intervention in the compliant group.

Association between Obstructive Sleep Apnea and Community-Acquired Pneumonia

BACKGROUND

We hypothesized that obstructive sleep apnea (OSA) can predispose individuals to lower airway infections and community-acquired pneumonia (CAP) due to upper airway microaspiration. This study evaluated the association between OSA and CAP.

METHODS

We performed a case-control study that included 82 patients with CAP and 41 patients with other infections (control group). The controls were matched according to age, sex and body mass index (BMI). A respiratory polygraph (RP) was performed upon admission for patients in both groups. The severity of pneumonia was assessed according to the Pneumonia Severity Index (PSI). The associations between CAP and the Epworth Sleepiness Scale (ESS), OSA, OSA severity and other sleep-related variables were evaluated using logistic regression models. The associations between OSA, OSA severity with CAP severity were evaluated with linear regression models and non-parametric tests.

FINDINGS

No significant differences were found between CAP and control patients regarding anthropometric variables, toxic habits and risk factors for CAP. Patients with OSA, defined as individuals with an Apnea-Hypopnea Index (AHI) ≥10, showed an increased risk of CAP (OR = 2·86, 95%CI 1·29-6·44, p = 0·01). Patients with severe OSA (AHI≥30) also had a higher risk of CAP (OR = 3·18, 95%CI 1·11-11·56, p = 0·047). In addition, OSA severity, defined according to the AHI quartile, was also significantly associated with CAP (p = 0·007). Furthermore, OSA was significantly associated with CAP severity (p = 0·0002), and OSA severity was also associated with CAP severity (p = 0·0006).

CONCLUSIONS

OSA and OSA severity are associated with CAP when compared to patients admitted to the hospital for non-respiratory infections. In addition, OSA and OSA severity are associated with CAP severity. These results support the potential role of OSA in the pathogenesis of CAP and could have clinical implications. This link between OSA and infection risk should be explored to investigate the relationships among gastroesophageal reflux, silent aspiration, laryngeal sensory dysfunction and CAP.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01071421.