Clinical Adult Literature Updates

Supra-Epiglottic Upper Airway Volume in Elderly Patients with Obstructive Sleep Apnea Hypopnea Syndrome

In this study, the authors compared upper airway volume in elderly patients with OSAS treated with CPAP vs. without CPAP. Sixty elderly volunteers (20 with OSAS, 20 with OSAS treated with CPAP, and 20 controls) underwent MRI. There was no significant differences in supra-epiglottic upper airway volume between OSAS, CPAP treated patients with OSAS and controls. The retropalatal distance and anteroposterior to transverse diameter ratio differed between OSAS, CPAP treated patients and controls. There was a significant correlation between BMI and retropalatal distance.

Pain Intensity and Opioid Utilization in Response to CPAP Therapy in Veterans with Obstructive Sleep Apnea on Chronic Opioid Treatment

This retrospective case-control study compared 113 patients with OSA taking opioids for non-malignant pain vs. a control group of patients with OSA who were not taking opioids at a VA sleep center. Pain intensity was assessed prior to CPAP treatment and at 12-month follow-up. Opioid intake was assessed using the morphine equivalent daily dose (MEDD) and CPAP adherence was assessed. CPAP adherence was lower in opioid treated patients vs. control (37% vs. 55%, p=0.01). Greater pain intensity was associated with CPAP non-adherence. CPAP treatment did not reduce pain intensity of consumption of opioids in veterans with chronic pain and OSA.

Comparison of Sugammadex Versus Neostigmine Costs and Respiratory Complications in Patients with Obstructive Sleep Apnea

In this prospective study, 74 patients undergoing otolaryngological procedures for OSA were randomized to receive sugammadex or neostigmine to reverse neuromuscular blockade at the end of surgery. Postoperative complications including respiratory (desaturation, re-intubation, unplanned ICU admission) and cardiovascular complications were higher in those receiving neostigmine vs. sugammadex. The total costs were higher in the neostigmine vs. sugamadex group due to the higher cost to treat complications in the group receiving neostigmine.

Effects of γ-Aminobutyric Acid Type A Receptor Modulation by Flumazenil on Emergence from General Anesthesia

Using a rodent model of emergence from general anesthesia, flumazenil or saline control was administered to animals following isoflurane anesthesia.  Animals receiving flumazenil were found to emerge more quickly from anesthesia and to demonstrate electroencephalographic patterns consistent with waking sooner.  Post-anesthesia changes in sleep time and NREM sleep time in saline treated animals were not detected in animals receiving flumazenil.

Continuous Positive Airway Pressure Mitigates Opioid-Induced Worsening of Sleep-Disordered Breathing Early after Bariatric Surgery

In a randomized crossover trial, 33 patients completed postoperative polysomnography in the postanesthesia care unit following bariatric surgery.  64% demonstrated sleep disordered breathing during recovery.  CPAP administration was associated with decreased apnea hypopnea index, fewer oxygen desaturations, and amelioration of the respiratory depressant effects of sleep-wake transitions and opioid administration.  No significant hemodynamic effects of CPAP were observed.

The STOP BANG Questionnaire and the Risk of Perioperative Respiratory Complications in Urgent Surgery Patients: A Prospective, Observational Study

STOP BANG positivity was associated with increased intraoperative (21% vs. 6%) and postoperative (57% vs. 34%) respiratory complications in adult patients undergoing urgent surgery under general anesthesia and the association remained significant after multivariate analysis.  Patients with positive STOP BANG scores also had longer average hospital stays (6 vs. 4 days).

The Association Between Obstructive Sleep Apnea and Alzheimer’s Disease: A Meta-Analysis Perspective

Alzheimer’s disease (AD) and obstructive sleep apnea (OSA) are highly prevalent, and the prevalence of OSA syndrome in patients with AD remains unknown. The auhtors collected all available published clinical data and analyzed them through a quantitative meta-analytical approach by calculating the aggregate odds ratio for OSA in AD vs. healthy control was 5.05 and homogeneous. This reflects that patients with AD have a five times higher chance of presenting with OSA than cognitively non-impaired individuals of similar age. Moreover, they also found that around half of patients with AD have experienced OSA at some point after their initial diagnosis. Future research should focus on the pathophysiological intercations betwneen the two syndromes, and establish causality. This evidence also promotes intensive screening for OSA amongst patients with AD.

Effects of Exercise Training on Sleep Apnoea in Patients with Coronary Artery Disease: a Randomised Trial

Overnight rostral fluid shift to the neck and lungs may contribute to the pathogenesis of obstructive sleep apnea (OSA) and central sleep apnea (CSA). The authors hypothesized that exercise training will decrease daytime leg fluid accumulation and overnight rostral fluid shift thereby decreasing the severity of OSA and CSA in patients with coronary artery disease (CAD). Patients with CAD and OSA or CSA (apnea-hypopnea index >15 events per h) were randomized to 4 weeks of aerobic exercise training or to a control group. The Apnea-hypopnea index decreased significantly more in the exercise group than in the control group (p=0.047), in association with a greater reduction in the overnight change in leg fluid volume (p=0.04) and by a significantly greater increase in the overnight change in UA-XSA in the exercise group (p=0.04). This study adds to the expanding literature and the beneficial effects of aerobic exercise in this vulnerable patient population.

Updated Adaptive Servo-Ventilation Recommendations for the 2012 AASM Guideline: “The Treatment of Central Sleep Apnea Syndromes in Adults: Practice Parameters with an Evidence-Based Literature Review and Meta-Analyses”

In light of recent results of a multicenter RCT (the SERVE-HF trail), and use of adaptive servo-ventilation (ASV) for the treatment of central sleep apnea syndrome (CSAS) related to congestive heart failure (CHF) has been controversial. An update of the 2012 systematic review and meta-analyses were performed that demonstrated an improvement in LVEF and a normalization of AHI in all patients. However, they also found that an increased risk of cardiac mortality in patients with an LVEF of ≤45% and moderate or severe CSA predominant sleep-disordered breathing. These data supported a Standard level recommendation against the use of ASV to treat CHF-associated CSAS in patients with an LVEF of ≤45% and moderate or severe CSAS, and an Option level recommendation for the use of ASV in the treatment CHF-associated CSAS in patients with an LVEF >45% and mild CSAS. The ultimate judgment regarding propriety of any specific care must be made by the clinician as per the AASM.

Is Perioperative Fluid and Salt Balance a Contributing Factor in Postoperative Worsening of Obstructive Sleep Apnea?

This article summarizes the evidence on the impact of fluid and salt balance on obstructive sleep apnea severity and reviews the potential anesthetic implications of excessive fluid and salt volume on worsening sleep apnea in the perioperative period.