March 2012

 

Nominate a Peer for Sleep Specialty Practitioner of the Year

We’re accepting nominations for our 2012 Specialty Practitioner of the Year Award now through July 31, so take a few moments to brainstorm deserving candidates and then nominate them via our online NOMINATION FORM. It’s a great way to recognize a fellow section member who you believe has gone above and beyond for our specialty.

OSA Severity Predicts Health Outcomes

U.S. and Canadian researchers who conducted an eight year follow up analysis of 1025 obstructive sleep apnea (OSA) patients and 494 non-apneic snorers are shedding some light on health risks for OSA patients. Overall results showed older age, male gender, and history of cardiovascular diseases or procedures are independently predictive of all-cause mortality. In a subgroup analysis based on age and gender, severe OSA, defined as an apnea hypopnea index (AHI) ≥ 30, was an independent predictor of mortality in males and patients under age 50. Maleness, age, and hypertension interacted with severe OSA to predict mortality and myocardial infarction. However, lower mortality rates were seen in males and those age 50 and older with severe OSA who used CPAP four or more hours per night. The authors conclude, “OSA severity was an important predictor of mortality in male and young OSA patients. CPAP use appeared protective in older and male severe OSA patients.” The study was published in the February issue of the Journal of Clinical Sleep Medicine. READ ABSTRACT

CPAP Therapy May Impact Coagulability

Studies have suggested that CPAP treatment for OSA reduces the risk of cardiovascular events. Australian researchers wondered whether CPAP may achieve this result through an effect on coagulability across the sleep-wake cycle. Their randomized crossover trial involved 28 patients with severe OSA who were assigned to either two months of therapeutic or placebo CPAP followed by a one month washout period. A 24 hour coagulation study was conducted after each treatment period. Compared with placebo CPAP, therapeutic CPAP resulted in lower 24 hour levels of von Willebrand Factor, factor VIII, and factor V, with the greatest difference seen during the nocturnal and early morning periods. Other coagulation factors were unchanged. The authors write, “These findings suggest that CPAP may reduce cardiovascular risk in OSA, in part through reducing risk of thrombosis.” The study was published ahead of print by Thorax on Feb. 14. READ ABSTRACT

Bi-Flex, CPAP Elicit Similar Results

A new study from investigators in Philadelphia and Denver compared the effect of CPAP with that of pressure release technology (Bi-Flex) on adherence and efficacy in children and adolescents with OSA. The randomized, double-blinded trial was conducted among 56 subjects who were assessed with polysomnography on pressure three months following randomization. Objective adherence data were collected at one and three month follow ups. Results showed both devices significantly decreased the AHI and the Epworth Sleepiness Scale. No statistical differences were seen in the number of nights the devices were turned on or the mean number of minutes they were used per night. However, the authors emphasize adherence was suboptimal for both methods of treatment. The study was published in the February issue of the Journal of Clinical Sleep Medicine. READ ABSTRACT

ODI May Predict SDB in Surgical Patients

Noting that it is impractical to perform polysomnography (PSG) on all surgical patients considered at risk for OSA, Canadian researchers tested the use of overnight PSG at home using a portable device and pulse oximeter in 217 males and 258 females with an average age of 60 and an average body mass index of 31. Results showed:

• The average AHI was 9.1 and 64% of patients had an AHI >5.
• There was a significant correlation between the oxygen desaturation index (ODI) and cumulative time percentage with Spo2 <90% from nocturnal oximetry and parameters measuring sleep breathing disorders from PSG.
• Compared to CT90, ODI had a stronger correlation and was a better predictor of AHI.
• The area under the receiver operator characteristics curve for ODI to predict AHI >5, AHI >15, and AHI >30 was 0.908, 0.931, and 0.958, respectively.
• The cutoff value based on the maximal accuracy for ODI to predict AHI >5, AHI >15, and AHI >30 was ODI >5, ODI >15, and ODI >30.
• The accuracy was 86% and 94%, respectively.
• ODI >10 demonstrated a sensitivity of 93% and a specificity of 75% to detect moderate and severe sleep disordered breathing (SDB).

The authors believe these findings show the “ODI from a high-resolution nocturnal oximeter is a sensitive and specific tool to detect undiagnosed SDB in surgical patients.” The study was published ahead of print by Anesthesia and Analygesia on Feb. 24. READ ABSTRACT