Literature Updates from January 2016

Polysomnographic Findings After Adenotonsillectomy for Obstructive Sleep Apnea in Obese and Non-Obese Children: A Systemic Review and Meta-Analysis

Meta-analysis of current literature shows T&A offers prominent improvement in a variety of sleep parameters. Improvements in non-obese children exceeded those for obese children. Postoperative residual OSA remained in roughly half of the children, especially those with severe disease and obesity, making additional treatment strategies and/or long-term follow-up highly desirable.

The Effect of Sex and Age on the Comorbidity Burden of OSA: An Observational Analysis from a Large Nationwide US Health Claims Database

In a large, nationally representative sample of working and retired people, OSA is strongly associated with significant comorbidities in both men and women with unique sex differences emerging.

The Cognitive Effects of Obstructive Sleep Apnea: An Updated Meta-Analysis

In this meta-analysis of 19 studies, authors investigated the cognitive function of obstructive sleep apnea (OSA) patients as measured through objective neuropsychological tests. They fund that many of the studies did not perform comprehensive neuropsychological examinations; with the majority using neuropsychological tests which indexed only a limited number of cognitive domains. However, they found statistically significant negative effect sizes in the cognitive domains of non-verbal memory, concept formation, psychomotor speed, construction, executive functioning, perception, motor control and performance, attention, speed of processing, working and verbal memory, verbal functioning and verbal reasoning. However, the extent of improvement of these symptoms with initiation of treatment such as CPAP, was not conducted due to lack of data.

Treatment Discontinuation Following Bariatric Surgery in Obstructive Sleep Apnea: a Controlled Cohort Study

Previous literature has suggested that discontinuation of obstructive sleep apnea (OSA) treatment after bariatric surgery (BS) occurs and associated with improvement in OSA severity following surgery. In this retrospective cohort study, patients with severe OSA on CPAP undergoing bariatric surgery were compared to a carefully matched sample of severe OSA patients on CPAP, but no bariatric surgery. Patients with BS stopped OSA treatment more often than controls, usually between 6 months and 1 year after BS: hazards ratio (HR (95 %, CI)) 15.93 (3.29, 77.00).

In the univariate analysis, patients were more likely to stop nocturnal positive airway pressure therapy after bariatric surgery if they were female, free of cardiovascular disease, if they had lost more than 18.4 % of body weight at 6 months after surgery, and exhibited lower OSA severity at baseline (<35 events/h). Prospective studies should investigate this relationship further.

Prediction of Oral Appliance Treatment Outcomes in Obstructive Sleep Apnea: A Systematic Review

Oral appliances can be useful in the management of OSA in patients with varying disease severity, and with variable treatment responses. It has been found that treatment response is not dependent solely on apnea hypopnea index severity, the prediction of OA treatment efficacy is of key importance for efficient disease management. This systematic review aims to investigate the accuracy of a variety of clinical and experimental tests for predicting OA treatment outcomes in OSA. The authors found that the predictive accuracy varied depending on the definitions of treatment success used as well as the type of index test. The studies with the best predictive accuracy and lowest risk of bias and concerns of applicability used a multi-sensor catheter. The highest accuracy was shown in a study using a remotely controlled mandibular positioner study, however, there was a high risk of bias. In the presence of CPAP no-compliance, alternative treatment strategies such as oral appliances can be useful in the management of OSA, and future studies should evaluate the cost and resource management issues pertaining the use of oral appliances.

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

The authors performed a retrospective review of 3 primary legal databases between 1991 and 2010 for cases involving adults with known or suspected OSA who had a surgical procedure associated with an adverse perioperative outcome (surgical mishaps were excluded). The adverse outcome had to result in a lawsuit adjudicated in a court of law with a final decision rendered. Twenty-four cases were identified. The patients were young, male, with a known diagnosis of OSA. Ninety-two percent of the cases were elective, with complications occurring intraoperatively (21%), in PACU (33%), and on the surgical floors (46%). The most common complications were respiratory arrest in an unmonitored setting and difficulty in airway management. Adverse outcomes included death, anoxic brain injury and upper airway complications. The use of opioids and general anesthesia were implicated in 38% and 58% of cases. In cases favoring the plaintiff, the financial penalty was high.

STOP-BANG Questionnaire as a Screening Tool for Diagnosis of Obstructive Sleep Apnea by Unattended Portable Monitoring Sleep Study

The authors conducted a retrospective chart review of 502 unattended portable monitoring sleep studies in order to assess the performance of the STOP-Bang questionnaire as a screening tool for diagnosis of OSA in patients undergoing portable sleep studies. STOP-Bang score thresholds of ≥ 7 and 8 were highly specific and had high PPV and may reduce the need for diagnostic sleep studies in selected patients.

An Integrative Model of Physiological Traits Can Be Used To Predict Obstructive Sleep Apnea and Response to Non-Positive Airway Pressure Therapy

In this study, 57 subjects with and without OSA underwent standard clinical and research sleep studies to measure OSA severity and the physiological traits important for OSA pathogenesis in order to develop a valid model to predict OSA. The model had good sensitivity and specificity for predicting OSA. This model may be used to predict population-wide and individual responses to non-PAP therapy.

Development and Validation of a Morphologic Obstructive Sleep Apnea Prediction Score: The DES-OSA Score

A morphology based OSA prediction score was developed based on clinical characteristics measured in 149 European patients and their overnight polysomnography results. The resulting DES-OSA score is based on assessment of Mallampati score, thyro-mental distance, BMI, neck circumference, and sex. The DES-OSA area under the curve for the receiver operating characteristic curves were between 0.81 and 0.84 for prediction of AHI events at >5, >15, and >30 per hour.

Effect of Melatonin on Sleep in the Perioperative Period After Breast Cancer Surgery: A Randomized, Double-Blind, Placebo-Controlled Trial

48 patients were randomized to receive 6mg melatonin or placebo for three preoperative nights, continuing into the postoperative period. As measured by actigraphy, melatonin was shown to increase sleep efficiency and decrease waking during the two weeks following surgery.