Clinical Adult Literature Updates from May 2015

Home-Use Servo-Ventilation Therapy in Chronic Pain Patients with Central Sleep Apnea: Initial and 3-Month Follow-Up

This prospective multicenter study recruited chronic pain patients prescribed ≥100 morphine equivalents for at least 4 months. Following PSG to confirm SDB, patients were randomized to lab PSG with either CPAP, ASV, and ASV with an initial mandatory pressure support of 6 cm H2O. After 3 months of home use of ASV, patients had lower AHI, CAI and OAI.

The Impact of Untreated Obstructive Sleep Apnea on Cardiopulmonary Complications in General and Vascular Surgery: A Cohort Study

This cohort study of adult patients undergoing general or vascular operations at 52 hospitals in Michigan used multivariable regression models to compare complication rates between treated and untreated OSA. Patients with OSA who were not treated with positive airway pressure preoperatively were at increased risk for cardiopulmonary complications after general and vascular surgery.

Severity of Obstructive Sleep Apnea is an Independent Predictor of Incident Atrial Fibrillation Hospitalization in a Large Sleep-Clinic Cohort

There is a paucity of data from large longitudinal cohorts to establish whether OSA is a risk factor for AF independent of obesity and other established risk factors. In this large population based study from Australia, 455 out of 6.841 study cases developed atrial fibrillation during a median follow-up of 11.9 years. After multivariate regression, independent predictors were OSA diagnosis (AHI > 5 events per hour) and severity of nocturnal hypoxia (SaO2 less than 90%). Future trials should examine the effect of treatment of OSA on atrial fibrillation.

The Use of a Fully Automated Automatic Adaptive Servo Ventilation Algorithm in the Acute and Chronic Treatment of Central Sleep Apnea

In this prospective, multicenter, observational trial, the effect of a fully automated Adaptive Servo-Ventilation (ASV) device on control of mixed sleep apnea (central as well as obstructive) was studied in patients on chronic opioids and those with congestive heart failure. Overnight, ASV titration improved AHI, CAI, obstructive apnea and arousal index significantly. Patients reported better sleep quality on ASV than CPAP. The mean adherence was 4.2 hours per night, and the daytime sleepiness also improved with significant reduction in the Epworth Sleepiness scale.

The First Night of CPAP: Impact on Memory Consolidation Attention and Subjective Experience

The overnight effect of use of CPAP on sleep-dependent motor memory consolidation (using motor sequence testing (MST)), as well as attention and vigilance (using psychomotor vigilance testing (PVT)) were examined in this prospective study. An instant augmentation of subjective experience and, based on PVT results, attention and vigilance after one night of CPAP, but a lack of an effect on offline sleep-dependent motor memory consolidation on the MST was observed. Using similar methodology, it will be interesting to observe the long-term effect of CPAP on PVT and MST, and how it impacts the neuro-cognitive recovery in patients with OSA.

Obstructive Sleep Apnea and Acute Respiratory Failure: An Analysis of Mortality Risk in Patients with Pneumonia Requiring Invasive Mechanical Ventilation

In this database analysis the authors the authors found that “in mechanically ventilated patients with pneumonia, OSA was associated with decreased in-hospital mortality and nonroutine discharge. They conclude that it is possible that differences in treatment pattern may partially explain improved survival.”

The Effects of Continuous Positive Airway Pressure on Postoperative Outcomes in Obstructive Sleep Apnea Patients Undergoing Surgery: A Systematic Review and Meta-Analysis

In this systematic literature review the authors sought “to investigate the effectiveness of continuous positive airway pressure (CPAP) in reducing the risk of postoperative adverse events in patients with OSA undergoing surgery, the perioperative Apnea-Hypopnea Index (AHI), and the hospital length of stay (LOS).” They concluded “that there was no significant difference in the postoperative adverse events between CPAP and no-CPAP treatment. Patients using CPAP had significantly lower postoperative AHI and a trend toward shorter LOS. There may be potential benefits in the use of CPAP during the perioperative period. “

Postoperative Complications in Patients with Obstructive Sleep Apnea: A Meta-Analysis

In this metaanalysis including 7,162 patients from 17 studies the authors found that “OSA was associated with significant increase in risk of respiratory failure [odds ratio (OR) 2.42; 95% confidence intervals (CI) 1.53 – 3.84; P = 0.0002] and cardiac events postoperatively (OR = 1.63; 95% CI 1.16 – 2.29; P = 0.005). ICU transfer occurred also more frequently in patients with OSA (OR 2.46; 95% CI 1.29 – 4.68; P = 0.006).”