Clinical Adult Literature Updates from July 2016

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).