Clinical Adult Literature Updates from July 2015

Comparison of Dexmedetomidine and Propofol Used for Drug-Induced Sleep Endoscopy in Patients with Obstructive Sleep Apnea Syndrome

Drug-Induced Sleep Endoscopy is a useful method to evaluate upper airway collapse using nasal endoscopy following pharmacologically induced somnolence in patients with OSA. In this randomized controlled trial, 40 patients were randomized to receive standardized doses of either propofol or dexmedetomidine infusion. Authors found that propofol provided rapid and deeper sedation and hemodynamic stability, and dexmedetomidine provided respiratory stability as well as adequate sedation level and better Aldrette scores in the recovery room, indicating advantages of dexmedetomidine. However, larger trials are needed to establish the generalizability of these results at other centers.

The Use of an Online Pictorial Epworth Sleepiness Scale in the Assessment of Age and Gender Specific Differences in Excessive Daytime Sleepiness

Use of cognitive aids in patient education and screening for OSA could be potentially useful, especially when used in conjunction with modern electronic media. In this study, an online pictorial Epworth Sleepiness Scale (ESS) was used to assess gender-related differences in excessive daytime somnolence (EDS) in a large sample of over 8000 patients. The range (0-24 points) and cut-off for EDS (ESS >10 points) was chosen in line with the traditional ESS. A gender gap was noted, in association with increased EDS with increasing age across both gender.

Perioperative Complications in Obstructive Sleep Apnea Patients Undergoing Surgery: A Review of the Legal Literature

Patients with OSA are associated with increased postoperative complications. A retrospective chart review of legal literature was conducted by searching three primary databases in the US, spanning 20 years. Adults with known or suspected OSA who underwent a surgical procedure, associated with a perioperative complication, were included. OSA had to be directly implicated in the outcome, and the perioperative outcome had to result in a lawsuit that was then adjudicated in a court of law with a final decision rendered. Most of the complications occurred in elective cases, and in the post-operative period. Use of opioids, general anesthesia played a role in 30-50% of cases. Verdicts favored the plaintiffs in 58% of cases and the average financial penalty was $2.5 million (±$2.3 million; range, $650,000-$7.7 million).

Obstructive Sleep Apnea: A Risk Factor for Surgical Site Infection Following Colectomy

This is a retrospective review of 507 colectomies, in which 42 patients had a diagnosis of OSA prior to surgery. These 42 patients were matched to 68 patients with a similar age, BMI, reason for surgery, surgical approach but without a diagnosis of OSA or diabetes. The rate of surgical site infection was 28.6% vs. 10.3% in patients with vs. without OSA, p=0.03. The odds for SSI was 3.98 in patients with OSA.

Sleep Apnoea and the Brain: A Complex Relationship

The authors review the evidence that OSA is a potentially modifiable risk factor for dementia. The effects of OSA on the central nervous system are reviewed. Both maladaptive and adaptive pathways initiated by nocturnal apneic and hypopneic episodes and ensuing sleep fragmentation are discussed.

Chronic Intermittent Hypoxia is Independently Associated with Reduced Postoperative Opioid Consumption in Bariatric Patients Suffering From Sleep-Disordered Breathing

This is a retrospective review including 218 patients who underwent laparoscopic bariatric surgery at Cleveland Clinic and who had an  available preoperative polysomnography study. The percentage of total sleep time spent at SaO2 < 90% was inversely associated with the total postoperative opioid consumption; a 5%- absolute increase in the former would relatively decrease median opioid consumption by 16%. The percentage of total sleep time spent at SaO2<90% was not associated with pain. The authors concluded that preoperative nocturnal intermittent hypoxia may enhance sensitivity to opioids.