Literature Updates from March 2018

Perioperative incidence of airway obstructive and hypoxemic events in patients with confirmed or suspected sleep apnea – a prospective, randomized pilot study comparing propofol/remifentanil and sevoflurane/remifentanil anesthesia

OSA is a risk factor for perioperative complications, however data on the impact of various anesthesia regimens on postoperative outcome is scarce. Randomized controlled study to assess the impact of propofol/remifentanil versus sevoflurane/remifentanil based anesthesia on nocturnal apnea-hypopnea index (AHI) and oxygen saturation. Neither the volatile agent sevoflurane nor the intravenous anesthetic propofol altered nocturnal AHI or oxygen saturation when combined with the short acting opioid remifentanil.

Knowledge Gaps in the Perioperative Management of Adults with Obstructive Sleep Apnea and Obesity Hypoventilation Syndrome. An Official American Thoracic Society Workshop Report

To identify knowledge gaps in the perioperative management of obstructive sleep apnea (OSA) and obesity hypoventilation syndrome (OHS). Further research is urgently needed to improve health outcomes for these patients. Currently evidence is insufficient to guide screening and optimization of OSA and OHS in the perioperative setting. Patients who are at greatest risk of respiratory or cardiac complications related to OSA and OHS are not well defined, and the effectiveness of monitoring and other interventions remains to be determined. Centers involved in sleep research need to develop collaborative networks to allow multicenter studies to address the knowledge gaps identified.

Perioperative Implementation of Noninvasive Positive Airway Pressure Therapies

Noninvasively applied positive airway pressure therapy (PAP) is available in 3 basic modes: continuous positive airway pressure (CPAP), bi-level positive airway pressure (BPAP), and adaptive servo-ventilation. They are increasingly being used perioperatively to prevent or treat upper airway obstruction, hypoventilation, and periodic breathing, and they have been found to improve postoperative outcomes in the case of obstructive sleep apnea. An impediment to their use in this setting is a lack of familiarity with their application by hospital clinical staff. This review describes the modes of PAP therapy available, their indications, how therapy is initiated, how efficacy is assessed, common problems encountered with its use, and how these problems can be addressed.

Barriers to Enhanced Recovery after Surgery after Laparoscopic Sleeve Gastrectomy

Enhanced Recovery after Surgery (ERAS) protocols lead to expedited discharges and decreased cost. Bariatric centers have adopted such programs for safely discharging patients after sleeve gastrectomy (LSG) on the first postoperative day (POD1), however this cannot be achieved in all patients.

In a retrospective review of patients undergoing LSG, from 2013 through 2016, using a standardized enhanced recovery pathway, treated OSA was associated with earlier hospital discharge. Understanding clinical and operative factors that enhance the success of ERAS as well as the causes and corrections for failed implementation allow teams to optimally direct care pathway resources.


Sleep-disordered breathing is associated with disturbed cardiac repolarization in patients with a coronary artery bypass graft surgery

This study demonstrates that OSA is associated with an increased risk of ventricular arrhythmias after coronary artery bypass graft surgery.

Obstructive sleep apnoea in adults: peri-operative considerations: A narrative review

This narrative review includes epidemiology, pathogenesis, and diagnosis of adult OSA patients. The article is well documented. It will help clinicians to deliver the best perioperative care.

Cardiac troponin values in patients with acute coronary syndrome and sleep apnea A pilot study

The authors compared peak cardiac troponin I (cTnI) levels in patients with OSA vs. patients without OSA who were admitted for an episode of acute coronary syndrome (ACS). They included 89 patients with OSA and 38 patients without OSA with a median AHI of 32. They reported that the peak cTnI was significantly higher in patients without OSA vs. with OSA. The multivariable linear regression analysis of the relationship between peak cTnI level and patient group, age, sex and type of ACS showed that the presence of OSA significantly contributed to the peak cTnI level. These results suggest that OSA – and intermittent hypoxia – has a protective effect in the context of myocardial infarction injury.

Associations between quantitative sleep EEG and subsequent cognitive decline in older women

This study examined whether quantitative sleep EEG changes pre-date the clinical development of mild cognitive impairment and/or incident dementia. Data from a nested case-control sample of women (mean age 83 yrs) from the Sleep and Cognition Study, an ancillary study to the longitudinal Study of Osteoporotic Fractures, were characterized as cognitively normal (MMSE>24) at the time of a baseline PSG is reported. A total of 85 women who developed new mild cognitive impairment or dementia by objective cognitive testing 5 years after PSG are included. Higher EEG power values were found in the dementia/mild cognitive impairment group for the alpha and theta bands in non-REM sleep and alpha and sigma bands in REM sleep. There was no group difference in traditional PSG measures of sleep architecture and sleep stage distribution, sleep apnea and periodic limb movement indices. These results suggest that quantitative EEG changes which precede the clinical onset of cognitive decline and the diagnosis of dementia in elderly women may be a potential biomarker for imminent cognitive decline.

Continuous positive airway pressure improves gait control in severe obstructive sleep apnoea: A prospective study

The authors examine the effect of 8 weeks of CPAP treatment on gait (as a cognitive task requiring attention and executive functioning resources) in non-obese patients with severe OSA in a prospective controlled trial. They included 12 severe OSA patients and 10 healthy matched subjects. They assessed spontaneous speed and stride time variability and the Stroop test before and after 8 weeks of CPAP. After CPAP treatment, stride time variability was significantly improved and cognitive performance under dual task was also improved. These results suggest using gait as a biomarker of OSA brain consequences.