Postoperative Outcomes in Obstructive Sleep Apnea Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis of Comparative Studies

Impact of obstructive sleep apnoea on postoperative outcomes of patients undergoing coronary artery bypass grafting: a systematic review and meta-analysis

OBJECTIVE

To assess the association between obstructive sleep apnoea (OSA) and postoperative complications in patients after coronary artery bypass graft (CABG).

METHODS

PubMed, Embase, Web of Science and Scopus databases were explored to identify relevant observational studies that reported incidences of OSA in CABG patients, and assessed OSA using standard objective methods such as polysomnography (PSG). The primary outcomes of interest were risk of major adverse cardiac and cerebrovascular events (MACCE) and all-cause mortality. Pooled effect sizes were reported as odds ratio (OR) with 95% confidence intervals.

RESULTS

Twelve studies were included. All studies, except one, had a prospective cohort design. CABG patients with OSA had increased risk of MACCE (OR 1.71, 95% CI: 1.16, 2.53), myocardial infarction (MI) (OR 2.21, 95% CI: 1.19, 4.13), pulmonary complications (OR 1.86, 95% CI: 1.03, 3.38), renal complications (OR 8.14, 95% CI: 2.07, 32.1), heart failure (OR 1.86, 95% CI: 1.19, 2.89) and need for revascularization (OR 2.80, 95% CI: 1.01, 7.75). However, risk of all-cause mortality (OR 1.63, 95% CI: 0.75, 3.52) was comparable in all patients.

CONCLUSION

This study showed that OSA significantly correlates with the increased risk of major adverse events. Our results indicate that recognizing and managing OSA in CABG patients is crucial for mitigating associated risks.

The STOP-Bang questionnaire: A narrative review on its utilization in different populations and settings

STUDY RATIONALE

Although the STOP-Bang questionnaire has been validated for its efficacy and diagnostic performance in various settings, there is no review that summarizes the pertinent evidence of the STOP-Bang questionnaire in the different populations. We aimed to review the evidence of the diagnostic performance of the STOP-Bang questionnaire, correlation between STOP-Bang scores and the probability of obstructive sleep apnea (OSA), and its clinical application in various populations.

STUDY IMPACT

This review guides healthcare providers in the sleep medicine and perioperative medicine disciplines to be better informed when using the STOP-Bang questionnaire in the different populations. It provides a greater understanding for both patients and clinicians when making decisions regarding OSA screening for each population.

Sleep apnea prevalence and severity after coronary revascularization versus no intervention: a systematic review & meta-analysis

PURPOSE

Obstructive sleep apnea (OSA) is a common disease in patients with coronary artery disease (CAD). Approximately 40-80% of cardiovascular disease patients have obstructive sleep apnea. The manifestation of it can vary significantly in different types of CAD patients. This systematic review and meta-analysis investigate the prevalence and severity of OSA in patients with acute coronary syndrome (ACS).

METHODS

This systematic review was conducted according to PRISMA guidelines. The first inclusion criteria were that a reliable sleep study had to be done after treating the patients' acute coronary incident. All patients in the studies included were adults suffering from an ACS who underwent either coronary artery bypass grafting surgery (CABG), a percutaneous coronary intervention (PCI) or had no invasive coronary intervention done. A search was conducted within four valid databases 27.1.2023 and all suitable articles published after 1.1.2010 were included.

RESULTS

Eight studies fulfilled the full inclusion criteria. In five of them, a sleep study had been performed after PCI, in two after no coronary intervention, and in one study after CABG. Mean AHI in no-OSA group after PCI was 9.5 /h (95% CI 5.3-13.7) and in the no intervention group 6.4 /h (95% CI 3.5-9.4). In OSA patients, mean AHI after PCI was 34.9 /h (95% CI 25.9-43.8) vs. 24.1 /h without intervention (95% CI 15.6-32.6).

CONCLUSIONS

Sleep apnea is very common among ACS patients and should be screened for and addressed after the acute coronary intervention. Moreover, we found that OSA is more severe in patients in whom PCI for ACS was indicated as opposed to patients who underwent no coronary intervention.

Differential Expression of mRNA in Peripheral Blood Mononuclear Cells May Predict Postoperative Atrial Fibrillation in Coronary Artery Bypass Surgery Patients

Postoperative Atrial Fibrillation (POAF) frequently follows Coronary Artery Bypass Grafting (CABG) surgery. This prospective study investigates genes linked to POAF in CABG patients, aiming to create a predictive model. Employing differential gene and methylation analyses, the study identified four genes (WARS2, CKAP2, CHI3L1, HSD17B6) associated with POAF. Preoperative plasma samples and clinical data were collected from 139 CABG patients, categorized into POAF (+) (43) and POAF (-) (96). Real-time quantitative PCR assessed gene expression, and a predictive model using the LASSO method demonstrated robust performance, with AUC values of 0.8895 in the training set and 0.7840 in the test set. This pioneering study integrates genomics and clinical data, suggesting WARS2, CKAP2, and CHI3L1 as potential indicators for POAF prediction.

Obstructive Sleep Apnea and Short-Term Outcomes After Pediatric Cardiac Surgery

Obstructive sleep apnea (OSA) has been associated with negative cardiovascular effects and negative outcomes following cardiovascular surgery in the adult population. Our objective was to evaluate if there is a similar association in children. Single center retrospective matched cohort study, we collected data on patients aged 1-18 who were admitted to the cardiac intensive care unit (CICU) between Jan 2012 and Dec 2021. We used a 3:1 propensity score matching for cases not diagnosed with OSA. Primary outcome was a composite variable: "adverse outcome," consisting of prolonged hospital and CICU stay, prolonged duration of mechanical ventilation, need for extracorporeal membrane oxygenation, and death. The study comprised 80 patients diagnosed with OSA and 240 patients without a diagnosis of OSA before cardiac surgery. The median age was 5.3 years (IQR 2.7-11.2). There were 184 (57.5%) males, and 102 (31.9%) had chromosomal and genetic abnormalities. There was a difference in "adverse outcome" between the OSA and non-OSA groups [34 (42.50%) vs 68 (28.33%), p = 0.027]. Moreover, bivariate analysis revealed that CICU length of stay, and chromosomal anomalies were statistically different between the groups. By logistic regression the composite variable "adverse outcome" remained associated to the OSA group (p = 0.009) with an adjusted odds ratio (OR) of 4.09 (1.83-9.18), p < 0.001. Children diagnosed with OSA had a higher risk of "adverse outcome" following cardiac surgery. The risk disappeared if the patient had Tonsillectomy and Adenoidectomy before cardiac surgery. Further studies should explore a proactive treatment for OSA in pediatric patients who need cardiac surgery.

Positive Airway Pressure in Surgical Patients with Sleep Apnea: What is the Supporting Evidence?

Obstructive sleep apnea (OSA) is prevalent amongst surgical patients and associated with an increased incidence of perioperative complications. The gold standard treatment for moderate-to-severe OSA is positive airway pressure (PAP) therapy. Practice guidelines by the American Society of Anesthesiologists and the Society of Anesthesia and Sleep Medicine have recommended preoperative screening for OSA and consideration of initiation of PAP therapy for patients with severe OSA. These guidelines, developed mainly by the consensus of experts, highlight the adverse impact of OSA on postoperative outcomes and recommend the use of postoperative PAP in surgical patients with moderate to severe OSA. Since the development of these guidelines, there has been an increase in the number of publications regarding the efficacy of PAP therapy in surgical patients with OSA. Our review provides an update on the existing literature on the efficacy of PAP therapy in surgical patients with OSA. We focus on the postoperative complications associated with OSA, potential mechanisms leading to the increased risk of postoperative adverse events, and summarize the perioperative guidelines for the management of patients with OSA, evidence supporting perioperative PAP therapy, as well as limitations to PAP therapy and alternatives. An update on the existing literature of the efficacy of PAP therapy in surgical patients with OSA is critical to assess the impact of prior guidelines, determine when and how to effectively implement PAP therapy, and target barriers to PAP adherence in the perioperative setting.

The use of preoperative continuous positive airway pressure in patients with obstructive sleep apnea following total knee arthroplasty: a propensity score matched analysis

INTRODUCTION

Patients with sleep apnea, affecting up to 1 in 4 older men in the United States, may be at increased risk of postoperative complications after total knee arthroplasty (TKA), including increased thromboembolic and cerebrovascular events, as well as respiratory, cardiac, and digestive complications. However, the extent to which the use of CPAP in patients with sleep apnea has been studied in TKA is limited.

METHODS

A national, all-payer database was queried to identify all patients who underwent a primary TKA between 2010 and 2021. Patients who had any history of sleep apnea were identified and then stratified based on the use of CPAP. A propensity score match analysis was conducted to limit the influence of confounders. Medical complications, such as cardiac arrest, stroke, pulmonary embolism, transfusion, venous thromboembolism, and wound complications, were collected at 90-days, 1-year, and 2-years.

RESULTS

The bivariate analysis showed inferior outcomes for sleep apnea with CPAP use compared to sleep apnea with no CPAP use, in terms of length of stay (5.9 vs. 5.2, p < 0.001), PJI (1.31% vs. 1.14%, p < 0.001), stroke (0.97% vs. 0.82%, p < 0.001), VTE (1.04% vs. 0.82, p < 0.001), and all other complications at 90-days (p < 0.001) except cardiac arrest (0.14% vs. 0.11%, p = 0.052), and aseptic revision (0.40% vs. 0.39%, p = 0.832), PJI (1.81% vs. 1.55%, p < 0.001) and aseptic revision (1.25% vs. 1.06%, p < 0.001) at 1-year, and PJI (2.07 vs. 1.77, p < 0.001) and aseptic revision (1.98 vs. 1.17, p < 0.001) at 2-years.

CONCLUSION

Patients with sleep apnea have increased postoperative complications after undergoing TKA in comparison to patients without sleep apnea. More severe sleep apnea, represented by CPAP usage in this study led to worse postoperative outcomes but further analysis is required signify the role of CPAP in this patient population. Patients with sleep apnea should be treated as a high-risk group.

Sleep-Disordered Breathing, Advanced Age, and Diabetes Mellitus Are Associated with De Novo Atrial Fibrillation after Cardiac Surgery

Background: Postoperative de novo atrial fibrillation (POAF) is one of the most frequently encountered complications following cardiac surgery. Despite the identification of several risk factors, the link between sleep-disordered breathing (SDB) and POAF has barely been examined. The objective of this prospective observational study was to determine whether severe SDB is associated with POAF in patients after elective coronary artery bypass grafting (CABG) surgery. Study design and methods: The incidence and preoperative predictors of in-hospital POAF were assessed in 272 patients undergoing CABG surgery at the University Medical Center Regensburg (Germany). In-hospital POAF was detected by continuous telemetry-ECG monitoring and 12-lead resting ECGs within the first seven postoperative days. POAF that occurred after hospital discharge within 60 days post CABG surgery was classified as post-hospital POAF and was ascertained by standardized phone interviews together with the patients' medical files, including routinely performed Holter-ECG monitoring at 60 days post CABG surgery. The night before surgery, portable SDB monitoring was used to assess the presence and type of severe SDB, defined by an apnea-hypopnea index ≥ 30/h. Results: The incidence of in-hospital POAF was significantly higher in patients with severe SDB compared to those without severe SDB (30% vs. 15%, p = 0.009). Patients with severe SDB suffered significantly more often from POAF at 60 days post CABG surgery compared to patients without severe SDB (14% vs. 5%, p = 0.042). Multivariable logistic regression analysis showed that severe SDB (odds ratio, OR [95% confidence interval, CI]: 2.23 [1.08; 4.61], p = 0.030), age ≥ 65 years (2.17 [1.04; 4.53], p = 0.038), and diabetes mellitus (2.27 [1.15; 4.48], p = 0.018) were significantly associated with in-hospital POAF. After additional adjustment for heart failure, the association between sleep apnea and postoperative atrial fibrillation was attenuated (1.99 [0.92; 4.31], p = 0.081). Conclusions: Amongst established risk factors, severe SDB was significantly associated with in-hospital POAF in patients undergoing CABG surgery. Whether SDB contributes to POAF independently of heart failure and whether risk for POAF may be alleviated by proper treatment of SDB merits further investigation.

The use of preoperative continuous positive airway pressure in patients with obstructive sleep apnea following total hip arthroplasty: A propensity score matched analysis

Introduction

Obstructive sleep apnea (OSA) impacts approximately 936 million individuals globally and is known to complicate post-surgical recovery, particularly after total hip arthroplasty (THA). While continuous positive airway pressure (CPAP) is commonly recommended for managing OSA, its effect on THA recovery remains uncertain. The study aimed to assess the impact of CPAP use on post-THA outcomes in patients with OSA, focusing on medical complications and periprosthetic joint infection (PJI) at 90 days and 1 year.

Methods

A national, all-payer database was utilized to identify patients undergoing primary THA between 2010 and 2021. Patients with OSA were stratified based on CPAP use through propensity score matching. Three matched groups were formed: OSA without CPAP, OSA with CPAP, and no OSA. Medical and surgical complications were assessed at 90 days and 1 year post-THA.

Results

Patients with OSA using CPAP exhibited more baseline comorbidities than those without CPAP. CPAP use was associated with inferior outcomes, including higher odds of PJI, wound complications, and venous thromboembolism at 90 days and 1 year post-THA. These trends were consistent even after adjusting for confounders.

Conclusion

CPAP use, indicative of severe OSA, was linked to worse post-THA outcomes, emphasizing the importance of recognizing OSA severity preoperatively. The study does not advocate for or against CPAP use but underscores the heightened risk in this patient population, guiding clinicians in tailoring perioperative strategies and counseling patients about potential risks.

Diagnostic Value of Neutrophil to Lymphocyte Ratio for Assessing Obstructive Sleep Apnea Risk in Surgical Patients

PURPOSE

Obstructive sleep apnea (OSA) is an important risk factor leading to perioperative complications in surgical patients. Neutrophil-to-lymphocyte ratio (NLR) is an important biomarker of increasing interest in recent years, and is used in the determination of systemic inflammatory response.

DESIGN

The aim of this study was to evaluate the risk of OSA and the relationship between OSA risk and NLR in surgical patients.

METHODS

The study was conducted in a tertiary care hospital between November 2021 and May 2022. The cross-sectional study included 604 patients who underwent surgery. OSA risk was evaluated with the STOP-Bang questionnaire in the preoperative evaluation in all patients. NLR was calculated as the ratio of neutrophil count to lymphocyte count.

FINDINGS

According to the STOP-Bang questionnaire, 62.3% of the patients had a high risk of OSA in the preoperative period. Patients who were male, elderly, obese, had hypertension, diabetes, chronic lung disease, and heart disease and polypharmacy were at greater risk of OSA. Patients at high risk of OSA had significantly higher NLR than patients at low risk of OSA. (2.65 vs 2.92, P.ß=.ß.024). NLR of 2.40 or higher predicted OSA risk with 58.8% sensitivity and 51.0% specificity (AUC.ß=.ß0.561) CONCLUSIONS: Most patients who were to undergo surgery had a high risk of OSA. NLR was higher in patients at high risk of OSA. Although the diagnostic efficacy is not high, NLR can be used to detect high OSA risk because it is a low-cost and easy to obtain biomarker.

Anesthesia for Morbidly Obese Patients

BACKGROUND

The prevalence of morbid obesity (BMI >35 kg/m2) has risen steadily in recent decades. With the corresponding rise in the number of bariatric operations, anesthesiologists deal with this patient group more commonly than before, particularly in specialized centers.

METHODS

This review is based on publications retrieved by a selective search in PubMed, including current guidelines and recommendations issued by specialist societies, as well as expert opinion.

RESULTS

In the anesthesiological care of morbidly obese patients, a preoperative assessment and risk stratification are just as important as the thoughtful selection of the anesthesia technique, the drugs used and their dosage, and perioperative management. A thorough understanding of the pathophysiological changes and comorbidities of morbid obesity and the associated risks is essential. The risk of pulmonary complications such as respiratory failure, hypoxia, and apnea is markedly higher in morbidly obese patients, especially those with obstructive sleep apnea. Short-acting, less lipophilic anesthetic drugs are particularly useful, as is multimodal pain therapy for the avoidance of high opiate doses. The indication for intensified postoperative monitoring depends on the patient's preexisting illnesses, the type of anesthesia, and the type of surgical procedure. Regional anesthetic techniques should be used if possible.

CONCLUSION

The perioperative care of morbidly obese patients presents special challenges. The anesthesiologist must be aware of potential comorbidities, specific risks, and pathophysiological changes in order to provide adequate care to this patient group.

Association between obstructive sleep apnea and atrial fibrillation and delirium after cardiac surgery. Sub-analysis of DECADE trial

BACKGROUND

Atrial fibrillation and delirium are common complications after cardiac surgery. Both are associated with increased Intensive Care Unit (ICU) and hospital length of stay, functional decline, 30-day mortality and increase in health care costs. Obstructive Sleep Apnea (OSA) induces deleterious effects in the cardiovascular and nervous systems. We hypothesized that adult patients with preoperative OSA have a higher incidence of postoperative atrial fibrillation and delirium than patients without OSA, after cardiac surgery.

METHODS

Sub-analysis of the DECADE trial at Cleveland Clinic hospitals. Our exposure was OSA, defined by STOP-BANG questionnaire score higher than 5 and/or a preoperative diagnosis of OSA. The primary outcome was atrial fibrillation, defined by clinician diagnosis or documented arrhythmia. The secondary outcome was delirium assessed twice during the initial five postoperative days using the Confusion Assessment Method for ICU. We assessed the association between OSA, and atrial fibrillation and delirium using a logistic regression model adjusted for confounders using inverse probability of treatment weighting.

RESULTS

590 patients were included in the final analysis. 133 were diagnosed with OSA and 457 had no OSA. Satisfactory balance between groups for most confounders (absolute standardized difference < 0.10) was achieved after weighting. The atrial fibrillation incidence was 37% (n = 49) in the patients with OSA and 33% (n = 150) in the non-OSA patients. OSA was not associated with atrial fibrillation with an estimated odds ratio of 1.22 (95% CI: 0.75,1.99;p = 0.416). The delirium incidence was 17% (n = 22) in patients with OSA and 15% (n = 67) in the non-OSA patients. OSA was not associated with delirium with an estimated odds ratio of 0.93 (95% CI: 0.51,1.69;p = 0.800).

CONCLUSION

In adult patients having cardiac surgery, OSA is not associated with a higher incidence of postoperative atrial fibrillation and delirium. These results suggest different prominent factors rather than OSA affect the incidence of these postoperative outcomes.

Sleep study measures on post-operative night one following expansion pharyngoplasty for obstructive sleep apnea

PURPOSE

To examine the changes in measures of sleep apnea severity and hypoxemia on the first post-operative night (PON1) following expansion pharyngoplasty as a means to assess the safety of same day discharge after surgery.

MATERIALS AND METHODS

Prospective cohort study of subjects with moderate-severe obstructive sleep apnea who underwent expansion pharyngoplasty at a single academic sleep surgical practice. A WatchPAT study was performed on the night immediately following surgery (PON1) and comparisons were made to baseline sleep testing.

RESULTS

Twenty subjects who had a mean age of 45.7 ± 10.8 years old and a mean body-mass index (BMI) of 31.4 ± 3.2 kg/m² were enrolled. Patients had baseline severe OSA with mean apnea hypopnea index (AHI) 39.4 ± 19.5/h, O2 nadir 80.8 ± 6.1 % and time with oxygen saturation below 88 % (T88) 12.3 ± 13.2 min. Measures of sleep apnea and nocturnal hypoxemia were not significantly different on PON1. AHI was increased by >20 % in 11 (55.0 %) patients. One patient demonstrated a >10 % worsening in O2 nadir, and 8 patients (45.0 %) demonstrated a >20 % worsening in T88. BMI over 32 was associated with elevated odds of worsening in T88, and anesthesia involving ketamine was associated with lower odds of a 20 % worsening in AHI or T88.

CONCLUSIONS

On PON1 following expansion pharyngoplasty, AHI and nocturnal hypoxemia are stable overall but variable on an individual basis. The decision for admission should therefore be made on a case-by-case basis. Further research is need to elucidate definitive predictors of worsening measures on PON1.

The effectiveness of positive airway pressure therapy in reducing postoperative adverse outcomes in surgical patients with obstructive sleep apnea: A systematic review and meta-analysis

IMPORTANCE

Obstructive sleep apnea (OSA) is prevalent in surgical patients and is associated with an increased risk of adverse perioperative events.

STUDY OBJECTIVE

To determine the effectiveness of positive airway pressure (PAP) therapy in reducing the risk of postoperative complications in patients with OSA undergoing surgery.

DESIGN

Systematic review and meta-analysis searching Medline and other databases from inception to October 17, 2021. The search terms included: "positive airway pressure," "surgery," "post-operative," and "obstructive sleep apnea." The inclusion criteria were: 1) adult patients with OSA undergoing surgery; (2) patients using preoperative and/or postoperative PAP; (3) at least one postoperative outcome reported; (4) control group (patients with OSA undergoing surgery without preoperative and/or postoperative PAP therapy); and (5) English language articles.

PATIENTS

Twenty-seven studies included 30,514 OSA patients undergoing non-cardiac surgery and 837 OSA patients undergoing cardiac surgery.

INTERVENTION

PAP therapy MAIN RESULTS: In patients with OSA undergoing non-cardiac surgery, PAP therapy was associated with a decreased risk of postoperative respiratory complications (2.3% vs 3.6%; RR: 0.72, 95% CI: 0.51-1.00, asymptotic P = 0.05) and unplanned ICU admission (0.12% vs 4.1%; RR: 0.44, 95% CI: 0.19-0.99, asymptotic P = 0.05). No significant differences were found for all-cause complications (11.6% vs 14.4%; RR: 0.89, 95% CI: 0.74-1.06, P = 0.18), postoperative cardiac and neurological complications, in-hospital length of stay, and in-hospital mortality between the two groups. In patients with OSA undergoing cardiac surgery, PAP therapy was associated with decreased postoperative cardiac complications (33.7% vs 50%; RR: 0.63, 95% CI: 0.51-0.77, P < 0.0001), and postoperative atrial fibrillation (40.1% vs 66.7%; RR: 0.59, 95% CI 0.45-0.77, P < 0.0001).

CONCLUSION

In patients with OSA undergoing non-cardiac surgery, PAP therapy was associated with a 28% reduction in the risk of postoperative respiratory complications and 56% reduction in unplanned ICU admission. In patients with OSA undergoing cardiac surgery, PAP therapy decreased the risk of postoperative cardiac complications and atrial fibrillation by 37% and 41%, respectively.

Prehabilitation of Cardiac Surgical Patients, Part 1: Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation

The concept of "prehabilitation" consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

DOISNORE50: a perioperative sleep questionnaire predictive of obstructive sleep apnea and postoperative medical emergency team activation. A learning health system approach to sleep questionnaire development and screening

STUDY OBJECTIVES

Patients with obstructive sleep apnea (OSA) have a disproportionate increase in postoperative complications and medical emergency team activation (META). We previously introduced DOISNORE50 (Diseases, Observed apnea, Insomnia, Snoring, Neck circumference > 18 inches, Obesity with BMI > 32, R = are you male, Excessive daytime sleepiness, 50 = age ≥ 50) from sleep questionnaire ISNORED using features associated with increased odds of META in perioperative patients. Performance of DOISNORE50 (DOISNORE) had yet to be tested.

METHODS

The performance of DOISNORE was tested along with questionnaire ISNORED and STOP-BANG questionnaires among 300 out of 392 participants without known OSA referred to the sleep lab. In study 2, the performance of DOISNORE was tested among 64,949 lives screened in perioperative assessment clinic from 2016 to 2020.

RESULTS

Receiver operating characteristic curve demonstrated that best performance was achieved with responses, with area under curve of 0.801. DOISNORE's predictability of OSA risk remained stable from 2018 to 2020 with area under curve of 0.78 and a Cronbach alpha of 0.65. Patients at high risk for OSA (DOISNORE ≥ 6) were associated with an increase of META (odds ratio 1.30, 95% confidence interval 1.12-1.45). Higher relative risk was noted among patients with congestive heart failure and hypercapnia.

CONCLUSIONS

DOISNORE is predictive of OSA and postoperative META. Perioperative strategies against META should consider DOISNORE questionnaire and focused screening among patients with heart failure and hypercapnia.

CITATION

Namen AM, Forest D, Saha AK, et al. DOISNORE50: a perioperative sleep questionnaire predictive of obstructive sleep apnea and postoperative medical emergency team activation. A learning health system approach to sleep questionnaire development and screening. J Clin Sleep Med. 2022;18(8):1909-1919.

Reduction in medical emergency team activation among postoperative surgical patients at risk for undiagnosed obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is an under-recognized condition that results in morbidity and mortality. Postoperative complications, including medical emergency team activation (META), are disproportionally increased among surgical patients at risk for OSA. A systematic approach is needed to improve provider recognition and treatment, but protocols that demonstrate improvement in META are lacking. As part of a multidisciplinary quality improvement project, DOISNORE50 (DIS), a sleep apnea questionnaire and proactive safety measure, was algorithmically applied to all perioperative patients.

METHODS

Consecutive sleep screening was conducted among perioperative patients. Of the 49,567 surgical navigation center patients, 11,932 had previous diagnosis of OSA. Of the 37,572 (96%) patients screened with DIS, 25,171 (66.9%) were Low Risk (DIS < 4), 9,211 (24.5%) were At Risk (DIS ≥ 4), and 3,190 (8.5%) were High Risk (DIS ≥ 6) for OSA, respectively. High Risk patients received same-day sleep consultation. On the day of surgery, patients with Known OSA, At Risk, and High Risk for OSA received an "OSA Precaution Band." An electronic chart reminder alerted admission providers to order postoperative continuous positive airway pressure (CPAP) machine and sleep consult for patients High Risk for OSA.

RESULTS

Implementation of a comprehensive program was associated with increased sleep consultation, sleep testing, and inpatient CPAP use (P < .001). For every 1,000 surgical patients screened, 30 fewer META, including rapid responses, reintubation, code blues, and code strokes, were observed. However, inpatient sleep consultation and inpatient CPAP use were not independently associated with reduced META. In the subgroup of patients hospitalized longer than 3 days, inpatient CPAP use was independently associated with reduced META.

CONCLUSIONS

In this single-center, institution-wide, multidisciplinary-approach, quality improvement project, a comprehensive OSA screening process and treatment algorithm with appropriate postoperative inpatient CPAP therapy and inpatient sleep consultations was associated with increased CPAP use and reduced META. Further prospective studies are needed to assess cost, feasibility, and generalizability of these findings.

CITATION

Namen AM, Forest D, Saha AK, et al. Reduction in medical emergency team activation among postoperative surgical patients at risk for undiagnosed obstructive sleep apnea. J Clin Sleep Med. 2022;18(8):1953-1965.

Postoperative Atrial Fibrillation in Adults with Obstructive Sleep Apnea Undergoing Coronary Artery Bypass Grafting in the RICCADSA Cohort

Postoperative atrial fibrillation (POAF) occurs in 20−50% of patients with coronary artery disease (CAD) after coronary artery bypass grafting (CABG). Obstructive sleep apnea (OSA) is also common in adults with CAD, and may contribute to POAF as well to the reoccurrence of AF in patients at long-term. In the current secondary analysis of the Randomized Intervention with Continuous Positive Airway Pressure (CPAP) in Coronary Artery Disease and Obstructive Sleep Apnea (RICCADSA) trial (Trial Registry: ClinicalTrials.gov; No: NCT 00519597), we included 147 patients with CABG, who underwent a home sleep apnea testing, in average 73 ± 30 days after the surgical intervention. POAF was defined as a new-onset AF occurring within the 30 days following the CABG. POAF was observed among 48 (32.7%) patients, occurring within the first week among 45 of those cases. The distribution of the apnea-hypopnea-index (AHI) categories < 5.0 events/h (no-OSA); 5.0−14.9 events/h (mild OSA); 15.0−29.9 events/h (moderate OSA); and ≥30 events/h (severe OSA), was 4.2%, 14.6%, 35.4%, and 45.8%, in the POAF group, and 16.2%, 17.2%, 39.4%, and 27.3%, respectively, in the no-POAF group. In a multivariate logistic regression model, there was a significant risk increase for POAF across the AHI categories, with the highest odds ratio (OR) for severe OSA (OR 6.82, 95% confidence interval 1.31−35.50; p = 0.023) vs. no-OSA, independent of age, sex, and body-mass-index. In the entire cohort, 90% were on β-blockers according to the clinical routines, they all had sinus rhythm on the electrocardiogram at baseline before the study start, and 28 out of 40 patients with moderate to severe OSA (70%) were allocated to CPAP. During a median follow-up period of 67 months, two patients (none with POAF) were hospitalized due to AF. To conclude, severe OSA was significantly associated with POAF in patients with CAD undergoing CABG. However, none of those individuals had an AF-reoccurrence at long term, and whether CPAP should be considered as an add-on treatment to β-blockers in secondary prevention models for OSA patients presenting POAF after CABG requires further studies in larger cohorts.

Postoperative outcomes in surgical patients with obstructive sleep apnoea diagnosed by sleep studies: a meta-analysis and trial sequential analysis

Identifying surgical patients with obstructive sleep apnoea may assist with anaesthetic management to minimise postoperative complications. Using trial sequential analysis, we evaluated the impact of obstructive sleep apnoea diagnosed by polysomnography or home sleep apnoea testing on postoperative outcomes in surgical patients. Multiple databases were systematically searched. Outcomes included: total postoperative complications, systemic complications (cardiovascular, respiratory, neurological, renal, infectious) and specific complications (atrial fibrillation, myocardial infarction, combined hospital and intensive care unit re-admission, mortality). The pooled odds ratios of postoperative complications were evaluated by the Mantel-Haenszel method random-effects model. Meta-analysis and meta-regression were conducted, and the GRADE approach was used to evaluate the certainty of evidence. Twenty prospective cohort studies with 3756 patients (2127 obstructive sleep apnoea and 1629 non-obstructive sleep apnoea) were included (9 in non-cardiac surgery and 11 in cardiac surgery). Postoperative complications were almost two-fold higher with obstructive sleep apnoea, OR (95%CI) 1.92 (1.52-2.42), p < 0.001; certainty of evidence, moderate. Obstructive sleep apnoea was associated with a 1.5 times increased risk of postoperative cardiovascular complications, OR (95%CI) 1.56 (1.20-2.02), p = 0.001; certainty of evidence, moderate; an almost two-fold increase in respiratory complications, OR (95%CI) 1.91 (1.39-2.62), p < 0.001; certainty of evidence, moderate; and hospital and ICU re-admission, OR (95%CI) 2.25 (1.21-4.19), p = 0.01; certainty of evidence, low. Trial sequential analysis showed adequate information size for postoperative complications. Baseline confounding factors were adjusted by meta-regression, and the sub-group analysis did not materially change our results. This increased risk occurred especially in patients in whom obstructive sleep apnoea had been newly diagnosed, emphasising the importance of pre-operative screening.

Preoperative screening of patients at high risk of obstructive sleep apnea and postoperative complications: A systematic review and meta-analysis

STUDY OBJECTIVE

To determine the association between postoperative complications and a high versus low risk of obstructive sleep apnea (OSA) as determined via screening tools.

DESIGN

Systematic review and meta-analysis of cohort studies. PubMed, EMBASE, Web of Science, and the Cochrane Library were searched from their inception to January 5, 2021.

SETTING

Operating room, postoperative recovery area, and ward.

PATIENTS

Adult patients scheduled for surgery.

INTERVENTIONS

We used Review Manager 5.4 to pool the data. The quality of evidence was rated using the Grading of Recommendations, Assessment, Development and Evaluation system.

MEASUREMENTS

The primary outcome was the composite endpoint of postoperative respiratory complications. The secondary outcomes were postoperative cardiac and neurological complications, intensive care unit (ICU) admission, and mortality.

MAIN RESULTS

Twenty-six studies with 50,592 patients were included. A STOP-Bang score ≥ 3 (versus <3) was associated with higher incidences of postoperative respiratory (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.66-2.68) and neurological complications (OR, 3.60; 95% CI, 1.56-8.31). A STOP-Bang score ≥ 5 (versus <5) was associated with higher incidences of postoperative respiratory (OR, 2.37; 95% CI, 1.11-5.04) and cardiac complications (OR, 4.95; 95% CI, 1.22-20.00) and higher in-hospital mortality (OR, 26.39; 95% CI, 2.89-241.30). A Berlin score ≥ 2 (versus <2) was not associated with the incidence of postoperative complications, ICU admission, or mortality. The quality of evidence for all outcomes was very low.

CONCLUSIONS

Very low-quality evidence suggested that a high risk of OSA, as assessed using the STOP-Bang questionnaire, was associated with a higher incidence of postoperative respiratory complications, and may also be associated with higher incidences of postoperative cardiac and neurological complications than a low risk of OSA. Since most of the included studies did not adjust for confounding factors, our findings need to be interpreted with caution. PROSPERO registration number: CRD42021220236.

Prevalence and Characteristics of Erectile Dysfunction in Obstructive Sleep Apnea Patients

BACKGROUND

Obstructive sleep apnea (OSA) is a common and severe social problem. Erectile dysfunction (ED) is an important health concern. The prevalence of OSA with ED is increasing, which significantly affects the quality of life and work efficiency of patients. However, the mechanism underlying the comorbidity of these two diseases remains unclear.

OBJECTIVES

(1) Investigate the prevalence of OSA with ED; (2) analyze the correlation between OSA and ED; and (3) explore the treatment response to and possible mechanism of uvulapalatopharyngoplasty (UPPP) in patients with OSA and ED. This study aims to provide a theoretical basis for the clinical diagnosis and comprehensive treatment of OSA with ED and improve prevention and treatment strategies.

MATERIALS AND METHODS

In total, 135 subjects were enrolled in the study. Clinical data, polysomnography, the ESS score, Beck anxiety score, Beck depression score, IIEF-5 score and ASEX score were recorded before UPPP and 6 months after UPPP. Sex hormones were measured for all subjects using a Roche electrochemiluminescence analyzer.

RESULT

The prevalence of OSA with ED was 64.52%, and the prevalence of severe OSA with ED was 73.02%. The prevalence of OSA with ED increased with age, BMI and apnea-hypopnea index (AHI) value. Among polysomnography indicators, minimum oxygen saturation and average oxygen saturation may predict the occurrence of OSA with ED. Improving the patient's anxiety and depression is very important for treating OSA with ED. Sex hormone levels were not significantly correlated with the occurrence of OSA with ED.

CONCLUSION

ED is a common symptom of OSA patients. This study showed that sex hormone levels in OSA patients with ED were not significantly correlated with the condition, but further investigation of this relationship is worthwhile. It is recommended that the free and combined types of sex hormones be further distinguished during testing because the free type is the active form. UPPP surgical treatment is effective for OSA with ED, and its possible mechanism is protection of the peripheral nerves of the sex organs by improving nighttime hypoxia and arousal.

Impact of obstructive sleep apnea on new-set atrial fibrillation after septal myectomy in patients with hypertrophic obstructive cardiomyopathy

Background

Obstructive sleep apnea (OSA) is associated with a higher prevalence of postoperative atrial fibrillation in patients who underwent cardiac surgery. However, whether OSA is a risk factor for postoperative atrial fibrillation after septal myectomy remains unclear. We hypothesized that OSA was associated with postoperative atrial fibrillation after septal myectomy.

Methods

A total of 99 patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy were included in our manuscript. Polysomnography was performed in all patients, and the heart rhythm was continuously monitored during the perioperative period.

Results

In the present study, 25 (25.3%) patients developed postoperative atrial fibrillation after septal myectomy. The prevalence of postoperative atrial fibrillation was significantly higher in patients with OSA and increased with the worsening severity of OSA. Notably, the apnea-hypoxia index was significantly higher in patients with postoperative atrial fibrillation among the different OSA groups. In receiver operating characteristic analysis, the area under the curve for the apnea-hypopnea index was 0.785 (95% CI: 0.684–0.887, P<0.001); an apnea-hypopnea index of 10.4 was the optimal cutoff point to predict postoperative atrial fibrillation. In the multivariable analysis, apnea-hypopnea index ≥10.4 (odds ratio: 6.29, 95% CI: 2.18–18.14, P=0.001), moderate-to-severe OSA (odds ratio: 4.88, 95% CI: 1.42–16.86, P=0.01), and left atrium diameter (odds ratio: 1.12, 95% CI: 1.03–1.22, P=0.01) were independent risk factors associated with postoperative atrial fibrillation after adjusting for relevant variables. However, the association between the diagnosis of OSA and postoperative atrial fibrillation was no longer statistically significant.

Conclusions

The severity of OSA reflected by the apnea-hypopnea index in patients with obstructive hypertrophic cardiomyopathy who underwent surgery is an independent risk factor for postoperative atrial fibrillation, which is associated with adverse clinical outcomes.

Sleep Study Measures on Postoperative Night 1 Following Implantation of the Hypoglossal Nerve Stimulator

OBJECTIVE

To examine the changes in measures of sleep apnea severity and hypoxemia on the first postoperative night following implantation of the hypoglossal nerve stimulator.

STUDY DESIGN

This was a single-arm prospective cohort study.

SETTING

A single academic sleep surgical practice.

METHODS

Subjects with moderate to severe obstructive sleep apnea underwent implantation of the hypoglossal nerve stimulator (HGNS) and were discharged to home the same day as surgery. A single-night WatchPAT study was performed on the night immediately following surgery (PON 1) and was compared to baseline sleep testing.

RESULTS

Twenty subjects who were an average of 58.6 ± 2.5 years old, were 25% female, and had a mean body mass index of 28.1 ± 0.9 kg/m² completed the study. Mean O₂ nadir at baseline was 79.6% ± 1.1% compared to 82.7% ± 0.9% (P = .013) on PON 1. One patient demonstrated a >10% worsening in O₂ nadir. Only 2 additional patients demonstrated a worsening in O₂ nadir on PON 1, each by only 1 percentage point. Neither mean time spent below SpO₂ 88% nor oxygen desaturation index (ODI) worsened postoperatively (mean time spent below oxygen saturation of 88%, 27.8 ± 7.85 vs 11.2 ± 5.2, P = .03; mean ODI, 29.6 ± 5.2/h vs 21.0 ± 5.4/h, P = .10). Mean obstructive apnea hypopnea index (AHI) was no worse (40.6 ± 4.7/h to 28.7 ± 4.2/h, P = .02), with only 2 patients experiencing an obstructive AHI >20% more severe than baseline. Only 1 patient demonstrated a clinically meaningful increase in central AHI on PON 1.

CONCLUSIONS

Overall, AHI and measures of nocturnal hypoxemia are stable, if not improved, on PON 1 following HGNS implantation. These findings support the safety of same-day discharge following implantation of the hypoglossal nerve stimulator.

Identification of Sleep Medicine and Anesthesia Core Topics for Anesthesia Residency: A Modified Delphi Technique Survey

BACKGROUND

Sleep disorders affect up to 25% of the general population and are associated with increased risk of adverse perioperative events. The key sleep medicine topics that are most important for the practice of anesthesiology have not been well-defined. The objective of this study was to determine the high-priority sleep medicine topics that should be included in the education of anesthesia residents based on the insight of experts in the fields of anesthesia and sleep medicine.

METHODS

We conducted a prospective cross-sectional survey of experts in the fields of sleep medicine and anesthesia based on the Delphi technique to establish consensus on the sleep medicine topics that should be incorporated into anesthesia residency curricula. Consensus for inclusion of a topic was defined as >80% of all experts selecting "agree" or "strongly agree" on a 5-point Likert scale. Responses to the survey questions were analyzed with descriptive statistical methods and presented as percentages or weighted mean values with standard deviations (SD) for Likert scale data.

RESULTS

The topics that were found to have 100% agreement among experts were the influence of opioids and anesthetics on control of breathing and upper airway obstruction; potential interactions of wake-promoting/hypnotic medications with anesthetic agents; effects of sleep and anesthesia on upper airway patency; and anesthetic management of sleep apnea. Less than 80% agreement was found for topics on the anesthetic implications of other sleep disorders and future pathways in sleep medicine and anesthesia.

CONCLUSIONS

We identify key topics of sleep medicine that can be included in the future design of anesthesia residency training curricula.

Predictive value of sleep apnea screenings in cardiac surgery patients

INTRODUCTION

Obstructive sleep apnea (OSA) is a highly prevalent disorder associated with increased cardiovascular risks. We explored the predictive value of OSA screening instruments in cardiac disease patients awaiting cardiac surgery.

METHODS

In this prospective cohort, 107 participants awaiting cardiac surgery from Cleveland Clinic and Johns Hopkins underwent polysomnography after completing Epworth Sleepiness Scale (ESS), Sleep Apnea/Sleep Disorder Questionnaire (SA/SDQ), STOP, STOPBAG₂ and Berlin questionnaires. Score comparisons between groups based on apnea-hypopnea index (AHI) ≥15 were performed. Logistic regression with receiver operating characteristic (ROC) analysis was used to investigate optimal threshold.

RESULTS

Prevalence of OSA (AHI ≥5) was 71.9% (77/107) and 51 (47.7%) had moderate-to-severe disease (AHI ≥15). Participants were primarily male (57%) and Caucasian (76.6%). Mean age was 67.3 ± 13.3 years and BMI was 26.5 ± 6.6. Of the five screening tools, STOPBAG₂ with a cut-point of 0.381 provided 78% sensitivity and 38% specificity (AUC 0.66, 95%CI 0.55-0.77). SA/SDQ yielded a cut-point of 32 for all subjects (AUC: 0.62, 95%CI 0.51-0.73) with sensitivity and specificity of 60% and 62% respectively, while STOP score ≥2 provided sensitivity and specificity of 67% and 52% respectively (AUC: 0.61, 95%CI 0.51-0.72). Among STOP items, "observed apnea" had the strongest correlation with AHI ≥15 (OR 3.67, 95%CI 1.57-8.54, p = 0.003). The ESS and Berlin were not useful in identifying moderate-to-severe OSA.

CONCLUSION

Common screening tools had suboptimal performance in cardiac surgery patients. STOPBAG₂ was better at predicting the probability of moderate-to-severe OSA in patients undergoing cardiac surgery compared to ESS, SA/SDQ, STOP and Berlin questionnaires.

Cardiac Surgery Outcomes: A Case for Increased Screening and Treatment of Obstructive Sleep Apnea

BACKGROUND

Due to the limited published information on complications that obstructive sleep apnea (OSA) patients experience during and after cardiac surgery, we are investigating OSA as a risk factor for post-operative outcomes.

METHODS

This project utilized the Northern New England Cardiovascular Disease Study Group's data collected between 2011 and 2017 based on the Society of Thoracic Surgeons Adult Cardiac Surgery Database Data Collections form. A retrospective analysis of 1,555 patients with OSA and 10,450 patients without OSA, across 5 medical centers undergoing isolated CABG, isolated valve, combined CABG valve surgery was conducted. We used 1:1 nearest neighbor propensity score matching with no replacement to balance characteristics among patients with and without OSA.

RESULTS

There was a statistically significant increased risk of post-operative pneumonia, increased length of total and post-operative stay, and time to initial extubation. Two outcomes trended towards significance: intra- and post-operative IABP use. Outcomes that failed to show statistical significance included: surgical site infection, atrial fibrillation cerebrovascular accident, permanent pacemaker placement, and blood products given. A chart review conducted on a subset of the study cohort revealed that more than 40% of OSA patients did not receive CPAP or BiPAP therapy post-operatively during their hospitalization.

CONCLUSIONS

Our study aligns with the literature in concluding that OSA has deleterious effects on post-operative outcomes of cardiac surgery patients. Further research to better stratify OSA patients by severity are still needed. Additionally, heightened awareness of the need to screen, diagnose, and properly treat patients for OSA is needed.

Obstructive sleep apnea-induced multi-organ dysfunction after elective coronary artery bypass surgery in coronary heart disease patients

Background

The aim of this study was to explore the underlying impact of obstructive sleep apnea (OSA) on postoperative parameters of multi-organ function among coronary heart disease (CHD) patients following elective coronary artery bypass grafting (CABG).

Methods

Electronic literature databases were searched manually and automatically for relevant English articles. All of the included articles focused on a comparison of the incidence of postoperative parameters of multi-organ function in CHD patients undergoing elective CABG with and without OSA. Studies were excluded if they met any one of the following criteria: (I) duplicate publication; (II) ongoing or unpublished studies; (III) only published as abstracts or conference proceedings; and (IV) less than 30 patients in the patient cohort.

Results

A total of 13 articles met our inclusion criteria. The current study demonstrated OSA significantly increased the incidence of major adverse cardiac and cerebrovascular events (MACCEs) in CHD patients undergoing elective CABG compared with the controls [odds risk (OR), 1.97; 95% CI, 1.50 to 2.59, P<0.0001]. In addition, OSA was associated with an increased risk of new revascularization in CHD patients undergoing elective CABG (OR, 9.47; 95% CI, 2.69 to 33.33, P<0.0001). Moreover, reintubation and tracheostomy in the OSA group was increased 243% (OR, 3.43; 95% CI, 1.35 to 8.71; P=0.009) and 372% (OR, 4.72; 95% CI, 1.23 to 18.13; P=0.024), respectively, compared with the control group. Besides, we also confirmed OSA significantly increased the acute kidney injury (AKI) incidence by 124% (OR, 2.24; 95% CI, 1.07 to 4.72; P<0.0001).

Conclusions

OSA may contribute to postoperative multi-organ dysfunction among CHD patients undergoing elective CABG by increasing the incidence of MACCEs, especially new revascularization, as well as respiratory, and renal complications.

Mechanisms, Prevention, and Treatment of Atrial Fibrillation After Cardiac Surgery: A Narrative Review

New onset of postoperative atrial fibrillation (AF) generally is recognized as a frequent and debilitating complication after cardiac surgery, contributing to a considerable health- care cost. Extensive research has been conducted to study the underlying mechanisms and risk factors of AF in the perioperative period. Many options have been suggested to lower the incidence, and the concurrent cost in health resources. This review attempts to synthesize the large body of existing literature on AF, as well as expand and illustrate the available knowledge on its management strategies. The latter incorporates recent developments in the anesthesthetic approach as well as in the pharmacologic arsenal. In addition, the current review provides a tool for understanding the pathophysiology of AF and for reducing the occurrence after cardiac surgery. By using it, clinicians can manage patients with AF in the perioperative period of cardiac surgery and minimize the relatively high economic cost that accompanies it.

New-Onset Atrial Fibrillation Detected by Continuous Capnography Monitoring: A Case Report

Case series

Patients: Male, 75-year-old • Male, 72-year-old

Final Diagnosis: Atrial fibrillation

Symptoms: Apnea • atrial fibrillation

Medication: —

Clinical Procedure: —

Specialty: Anesthesiology

Sleep apnoea and cardiovascular outcomes after coronary artery bypass grafting

OBJECTIVE

Patients with advanced coronary artery disease are referred for coronary artery bypass grafting (CABG) and it remains unknown if sleep apnoea is a risk marker. We evaluated the association between sleep apnoea and major adverse cardiac and cerebrovascular events (MACCE) in patients undergoing non-emergent CABG.

METHODS

This was a prospective cohort study conducted between November 2013 and December 2018. Patients from four public hospitals referred to a tertiary cardiac centre for non-emergent CABG were recruited for an overnight sleep study using a wrist-worn Watch-PAT 200 device prior to CABG.

RESULTS

Among the 1007 patients who completed the study, sleep apnoea (defined as apnoea-hypopnoea index ≥15 events per hour) was diagnosed in 513 patients (50.9%). Over a mean follow-up period of 2.1 years, 124 patients experienced the four-component MACCE (2-year cumulative incidence estimate, 11.3%). There was a total of 33 cardiac deaths (2.5%), 42 non-fatal myocardial infarctions (3.7%), 50 non-fatal strokes (4.9%) and 36 unplanned revascularisations (3.2%). The crude incidence of MACCE was higher in the sleep apnoea group than the non-sleep apnoea group (2-year estimate, 14.7% vs 7.8%; p=0.002). Sleep apnoea predicted the incidence of MACCE in unadjusted Cox regression analysis (HR 1.69; 95% CI 1.18 to 2.43), and remained statistically significant (adjusted HR 1.57; 95% CI 1.09 to 2.25), after adjustment for age, sex, body mass index, left ventricular ejection fraction, diabetes mellitus, hypertension, chronic kidney disease and excessive daytime sleepiness.

CONCLUSION

Sleep apnoea is independently associated with increased MACCE in patients undergoing CABG.

TRIAL REGISTRATION NUMBER

NCT02701504.

Methodological tools and sensitivity analysis for assessing quality or risk of bias used in systematic reviews published in the high-impact anesthesiology journals

Background

A crucial element in the systematic review (SR) methodology is the appraisal of included primary studies, using tools for assessment of methodological quality or risk of bias (RoB). SR authors can conduct sensitivity analyses to explore whether their results are sensitive to exclusion of low quality studies or a high RoB. However, it is unknown which tools do SR authors use for assessing quality/RoB, and how they set threshold for quality/RoB in sensitivity analyses. The aim of this study was to assess quality/RoB assessment tools, the types of sensitivity analyses and quality/RoB thresholds for sensitivity analyses used within SRs published in high-impact pain/anesthesiology journals.

Methods

This was a methodological study. We analyzed SRs published from January 2005 to June 2018 in the 25% highest-ranking journals within the Journal Citation Reports (JCR) “Anesthesiology” category. We retrieved the SRs from PubMed. Two authors independently screened records, full texts, and extracted data on quality/RoB tools and sensitivity analyses. We extracted data about quality/RoB tools, types of sensitivity analyses and the thresholds for quality/RoB used in them.

Results

Out of 678 analyzed SRs, 513 (76%) reported the use of quality/RoB assessments. The most commonly reported tools for assessing quality/RoB in the studies were the Cochrane tool for risk of bias assessment (N = 251; 37%) and Jadad scale (N = 99; 15%). Meta-analysis was conducted in 451 (66%) of SRs and sensitivity analysis in 219/451 (49%). Most commonly, sensitivity analysis was conducted to explore the influence of study quality/RoB (90/219; 41%) on the results. Quality/RoB thresholds used for sensitivity analysis for those studies were clearly reported in 47 (52%) articles that used them. The quality/RoB thresholds used for sensitivity analyses were highly heterogeneous and inconsistent, even when the same tool was used.

Conclusions

A quarter of SRs reported using quality/RoB assessments, and some of them cited tools that are not meant for assessing quality/RoB. Authors who use quality/RoB to explore the robustness of their results in meta-analyses use highly heterogeneous quality/RoB thresholds in sensitivity analyses. Better methodological consistency for quality/RoB sensitivity analyses is needed.

Prevalence of Undiagnosed Obstructive Sleep Apnea Among Patients Hospitalized for Cardiovascular Disease and Associated In-Hospital Outcomes: A Scoping Review

BACKGROUND

Obstructive sleep apnea (OSA) is associated with long-term cardiovascular morbidity and is highly prevalent in patients with cardiovascular disease (CVD). The objectives of this scoping review were to determine the prevalence of OSA inpatients hospitalized for CVD and to map the range of in-hospital outcomes associated with OSA.

METHODS

We searched MEDLINE(R), Embase, and Cochrane Databases for articles published from 1946-2018. We included studies involving non-surgical adults with OSA or at high risk of OSA who were hospitalized for CVD. The outcomes were considered as in-hospital if they were collected from admission up to 30 days post-discharge from hospital.

RESULTS

After the screening of 4642 articles, 26 studies were included for qualitative synthesis. Eligible studies included patients presenting with acute coronary syndromes (n = 19), congestive heart failure (n = 6), or any cardiovascular disease (n = 1). The pooled prevalence of OSA in cardiac inpatients was 48% (95% CI: 42-53). The in-hospital outcomes reported were mortality (n = 4), length of stay (n = 8), left ventricular ejection fraction (n = 8), peak troponin (n = 7), peak B-type natriuretic peptide (n = 4), and composite cardiovascular complications (n = 2).

CONCLUSIONS

OSA is highly prevalent in the cardiac inpatient population. The outcomes reported included mortality, cardiac function, cardiac biomarkers, and resource utilization. There are significant knowledge gaps regarding the effect of treatment and OSA severity on these outcomes. The findings from this review serve to inform further areas of research on the management of OSA among patients with CVD.

Postoperative Outcomes of Patients With Obstructive Sleep Apnea Undergoing Cardiac Surgery

BACKGROUND

Obstructive sleep apnea (OSA) is associated with increased risk of postoperative complications in noncardiac surgery, with limited literature on cardiac surgical patients. Perioperative outcomes of patients with OSA were compared with outcomes of those without OSA undergoing cardiac surgery.

METHODS

This was a retrospective single-center cohort study of adults who underwent cardiac surgery from January 2010 to April 2017. Outcomes of patients with OSA were compared with those without OSA, including length of stay, readmissions, hospital death, and short-term outcomes.

RESULTS

OSA was present in 2636 of 8612 patients (30.6%) identified during the study period with OSA. Patients with OSA had a longer median length of stay (6 vs 5 days, P < .001), longer incidence of prolonged (>7 days) length of stay (26.3% vs 23.0%, P < .001), and were less likely to be discharged to home (78.2% vs 84.4%, P < .001). OSA patients also had a higher 30-day readmission rate (14.7% vs 10.4%, P < .001). Acute kidney injury was more common in OSA patients (25.2% vs 19.9%, P < .001). Our multivariable model found postoperative atrial fibrillation was associated with older age and not OSA status (age <50 years compared with >75 years; odds ratio, 4.10; 95% confidence interval, 3.39-4.96).

CONCLUSIONS

OSA patients had a longer mean length of stay, were more likely to have a prolonged length of stay, more likely to be discharged to a location other than home, and had a higher 30-day readmission rate. This suggests higher resource utilization is required to care for OSA patients after cardiac surgery.

Hospital outcomes in non-surgical patients identified at risk for OSA

BACKGROUND

In-hospital respiratory outcomes of non-surgical patients with undiagnosed obstructive sleep apnea (OSA), particularly those with significant comorbidities are not well defined. Undiagnosed and untreated OSA may be associated with increased cardiopulmonary morbidity.

STUDY OBJECTIVES

Evaluate respiratory failure outcomes in patients identified as at-risk for OSA by the Berlin Questionnaire (BQ).

METHODS

This was a retrospective study conducted using electronic health records at a large health system. The BQ was administered at admission to screen for OSA to medical-service patients under the age of 80 years old meeting the following health system criteria: (1) BMI greater than 30; (2) any of the following comorbid diagnoses: hypertension, heart failure, acute coronary syndrome, pulmonary hypertension, arrhythmia, cerebrovascular event/stroke, or diabetes. Patients with known OSA or undergoing surgery were excluded. Patients were classified as high-risk or low-risk for OSA based on the BQ score as follows: low-risk (0 or 1 category with a positive score on the BQ); high-risk (2 or more categories with a positive score on BQ). The primary outcome was respiratory failure during index hospital stay defined by any of the following: orders for conventional ventilation or intubation; at least two instances of oxygen saturation less than 88% by pulse oximetry; at least two instances of respiratory rate over 30 breaths per minute; and any orders placed for non-invasive mechanical ventilation without a previous diagnosis of sleep apnea. Propensity scores were used to control for patient characteristics.

RESULTS

Records of 15,253 patients were assessed. There were no significant differences in the composite outcome of respiratory failure by risk of OSA (high risk: 11%, low risk: 10%, p = 0.55). When respiratory failure was defined as need for ventilation, more patients in the low-risk group experienced invasive mechanical ventilation (high-risk: 1.8% vs. low-risk: 2.3%, p = 0.041). Mortality was decreased in patients at high-risk for OSA (0.86%) vs. low risk for OSA (1.53%, p < 0.001).

CONCLUSIONS

Further prospective studies are needed to understand the contribution of undiagnosed OSA to in-hospital respiratory outcomes.

Chronic hypoxia–induced Cirbp hypermethylation attenuates hypothermic cardioprotection via down-regulation of ubiquinone biosynthesis

Therapeutic hypothermia is commonly used during cardiopulmonary bypass (CPB) to protect the heart against myocardial injury in cardiac surgery. Patients who suffer from chronic hypoxia (CH), such as those with certain heart or lung conditions, are at high risk of severe myocardial injury after cardiac surgery, but the underlying mechanisms are unknown. This study tested whether CH attenuates hypothermic cardioprotection during CPB. Using a rat model of CPB, we found that hypothermic cardioprotection was impaired in CH rats but was preserved in normoxic rats. Cardiac proteomes showed that cold-inducible RNA binding protein (CIRBP) was significantly (P = 0.03) decreased in CH rats during CPB. Methylation analysis of neonatal rat cardiomyocytes under CH and myocardium specimens from patients with CH showed that CH induced hypermethylation of the Cirbp promoter region, resulting in its depression and failure to respond to cold stress. Cirbp-knockout rats showed attenuated hypothermic cardioprotection, whereas Cirbp-transgenic rats showed an enhanced response. Proteomics analysis revealed that the cardiac ubiquinone biosynthesis pathway was down-regulated during CPB in Cirbp-knockout rats, resulting in a significantly (P = 0.01) decreased concentration of ubiquinone (CoQ10). Consequently, cardiac oxidative stress was aggravated and adenosine 5′-triphosphate production was impaired, leading to increased myocardial injury during CPB. CoQ10-supplemented cardioplegic solution improved cardioprotection in rats exposed to CH, but its effect was limited in normoxic rats. Our study suggests that an individualized cardioprotection strategy should be used to fully compensate for the consequences of epigenetic modification of Cirbp in patients with CH who require therapeutic hypothermia.

Risk factors for opioid-induced respiratory depression in surgical patients: a systematic review and meta-analyses

OBJECTIVE

This systematic review and meta-analysis aim to evaluate the risk factors associated with postoperative opioid-induced respiratory depression (OIRD).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed-MEDLINE, MEDLINE in-process, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PubMed and Clinicaltrials.gov (January 1946 to November 2017).

ELIGIBILITY CRITERIA

The inclusion criteria were: (1) adult patients 18 years or older who were administered opioids after surgery and developed postoperative OIRD (OIRD group); (2) all studies which reported both OIRD events and associated risk factors; (3) all studies with reported data for each risk factor on patients with no OIRD (control group) and (4) published articles in English language.

DATA ANALYSIS

We used a random effects inverse variance analysis to evaluate the existing evidence of risk factors associated with OIRD. Newcastle-Ottawa scale scoring system was used to assess quality of study.

RESULTS

Twelve observational studies were included from 8690 citations. The incidence of postoperative OIRD was 5.0 cases per 1000 anaesthetics administered (95% CI: 4.8 to 5.1; total patients: 841 424; OIRD: 4194). Eighty-five per cent of OIRD occurred within the first 24 hours postoperatively. Increased risk for OIRD was associated with pre-existing cardiac disease (OIRD vs control: 42.8% vs 29.6%; OR: 1.7; 95% CI: 1.2 to 2.5; I²: 0%; p<0.002), pulmonary disease (OIRD vs control: 17.8% vs 10.3%; OR: 2.2; 95% CI: 1.3 to 3.6; I²: 0%; p<0.001) and obstructive sleep apnoea (OIRD vs control: 17.9% vs 16.5%; OR: 1.4; 95% CI: 1.2 to 1.7; I²: 31%; p=0.0003). The morphine equivalent daily dose of the postoperative opioids was higher in the OIRD group than in the control; (24.7±14 mg vs 18.9±13.0 mg; mean difference: 2.8; 95% CI: 0.4 to 5.3; I²: 98%; p=0.02). There was no significant association between OIRD and age, gender, body mass index or American Society of Anesthesiologists physical status.

CONCLUSION

Patients with cardiac, respiratory disease and/or obstructive sleep apnoea were at increased risk for OIRD. Patients with postoperative OIRD received higher doses of morphine equivalent daily dose.

Preoperative Evaluation: Estimation of Pulmonary Risk Including Obstructive Sleep Apnea Impact

One in 4 deaths occurring within a week of surgery are related to pulmonary complications, making it the second most common serious morbidity after cardiovascular events. The most significant predictors of the postoperative pulmonary complications (PPCs) are American Society of Anesthesiologists physical status, advanced age, dependent functional status, surgical site, and duration of surgery. The overall risk of PPCs can be predicted using scores that incorporate readily available clinical data.

Clinical use of the STOP-BANG questionnaire to determine postoperative risk in veterans

OBJECTIVES

To determine whether STOP-BANG (snoring, tiredness, observed apnea, high blood pressure, body mass index, age, neck circumference, gender) scores are associated with immediate postoperative adverse events in veterans undergoing surgery.

METHODS

In this prospective cohort study, veterans presenting to the presurgical clinic at a Veterans Affairs hospital answered the STOP-BANG questionnaire, which was scored as high risk (5-8), intermediate risk (3-4), and low risk (0-2) for obstructive sleep apnea (OSA), during a 6-month study period. Immediate postoperative respiratory and cardiovascular adverse events were recorded.

RESULTS

The patient population included 1,080 veterans. Ninety-five patients (8.8%) experienced adverse events, of which 74 (6.9%) were respiratory and 21 (1.9%) were cardiovascular in nature. Patients with high-risk STOP-BANG scores (5-8) had significantly greater odds of having an adverse event odds ratio (OR) 2.1 (95% confidence interval [CI]: 1.4, 3.3) and hypoxia OR 2.8 (95% CI: 1.7, 4.6) compared to those with low- to intermediate-risk scores (0-4). Among patients with OSA, those with high-risk scores (5-8) had greater odds of an adverse event OR 3.9 (95% CI: 1.1, 13.9) and hypoxia OR 3.7 (95% CI: 1.1, 13.0) compared to those with low- to intermediate-risk scores (0-4). Patients without a history of OSA with high-risk scores (5-8) did not have significantly greater odds of an adverse event OR 1.5 (95% CI: 0.82, 2.6) or a hypoxic event OR 1.7 (95% CI: 0.87, 3.4) compared to those with low- to intermediate-risk scores (0-4).

CONCLUSION

The STOP-BANG questionnaire was useful in the veteran population because high-risk scores were predictive of adverse events, in particular, hypoxia for patients with a previous diagnosis of OSA. In the future, this may direct studies and clinical activities aimed at optimizing safe and effective perioperative practices.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:259-264, 2019.

Usefulness of the STOP-Bang Questionnaire in a Cardiac Surgical Population

OBJECTIVE

The aim of this study was to assess the predictive accuracy of the STOP-Bang questionnaire in relation to obstructive sleep apnea (OSA) detected by nocturnal oximetry, as well as postoperative outcomes, in a population undergoing cardiac surgery.

DESIGN

A prospective observational cohort study.

SETTING

The specialist cardiothoracic center at the Royal Papworth Hospital, Cambridge University Health Partners, United Kingdom.

PARTICIPANTS

All adult patients, undergoing elective coronary artery bypass grafting with or without cardiac valve surgery between March 2013 and July 2014 were included. The authors excluded patients participating in other interventional studies, those who had a tracheostomy before surgery, and those who required emergency surgery or were due to be admitted on the day of surgery.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Cardiac surgical patients were screened for the risk of OSA with the use of STOP-Bang questionnaire. The presence of OSA prior to surgery was assessed with overnight oximetry. The predictive performance of the STOP-Bang questionnaire was assessed by calculating sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC)-receiver operating characteristic curve (ROC). Multiple-logistic regression models were used to assess for associations between the STOP-Bang scores and postoperative outcomes. The STOP-Bang questionnaire discriminated poorly between mild OSA (AUC-ROC 0.57 [95% confidence interval (CI) 0.47-0.67]) and moderate/severe OSA (AUC-ROC 0.82 (95% CI 0.69-0.95)]. Accuracy was increased by modifying the cut-off value to 6 or greater, with sensitivity and specificity of 75% and 77%, respectively. A STOP-Bang score indicating the possibility of OSA was not significantly associated with prolonged intensive care unit lengths of stay (hazard ratio [HR] 1.1; 95% CI 0.99-1.19; p = 0.08) or postoperative complications (odds ratio [OR] 1.0; 95% CI 0.59-1.72; p = 0.98).

CONCLUSIONS

In the study population, a STOP-Bang questionnaire score of 3 or greater had limited predictive value for identifying cardiac surgical patients at high risk of OSA. STOP-Bang scores were not significantly associated with worse postoperative outcomes. A STOP-Bang score of 6 or greater could help identify patients in need of a sleep study to confirm the presence of OSA as such patients may be at increased risk of postoperative complications.