March 2010

Coming Soon: New and Improved Section Listserve
The AARC is getting ready to launch an exciting new social networking site for members called AARC Connect, and our section’s listserve will be moving to the new site as soon as it’s up and running. Now we’ll not only be able to communicate with each other in real time, we’ll also be able to view specific threads with ease, view posts by specific members, and much, much more.

Fixed-Pressure, Variable-Pressure CPAP Perform about the Same
British researchers who compared fixed-pressure and variable-pressure CPAP in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) found little difference between the two treatments. The randomized, blinded, crossover trial was conducted among 181 patients who used each of the devices for six weeks. At the end of the study 72 patients said they preferred fixed-pressure CPAP and 69 preferred variable-pressure CPAP. Slightly lower Epworth scores and slightly higher mean CPAP use were seen with the variable-pressure device. The research was published in the February issue of Sleep. READ ABSTRACT

Bi-PAP Can Benefit SMA Patients, if Therapy is Optimized
Children with spinal muscle atrophy (SMA) type II can benefit from Bi-PAP, but the effects on heart rate and blood pressure are unknown. Swedish researchers set out to determine those effects in a study conducted among ten children ages 8–12 who were evaluated during an overnight sleep study. Results showed comparable heart rate and blood pressure measurements during unsupported breathing and on optimal Bi-PAP. Blood gases were also similar. However, sub-optimal Bi-PAP due to air leaking from the mask was associated with marked increases in breath-to-breath variability of heart rate, blood pressure measurements, and phase angle. The authors conclude, “Bi-PAP therapy does not appear to adversely influence hemodynamics in children with SMA if pressures are optimized and the mask is correctly applied and sealed.” The study appeared in the Jan. 9 Epub edition of Sleep Medicine. READ ABSTRACT

Nightmare Recall Worse in Severe OSA
A new study out of the University of Colorado suggests people with severe obstructive sleep apnea (OSA) are less likely to recall nightmares. Researchers looked at 393 people undergoing clinical polysomnography. The patients also completed a general intake questionnaire that asked about dream and nightmare recall. The mean apnea-hypopnea index (AHI) in the group was 34.9. Both the AHI and apnea index were significantly higher in the patients who reported infrequent recall of nightmares. “Patients with higher AHI report a lower nightmare frequency, indicating that significant OSA suppresses the cognitive experience of nightmare recall,” write the authors. “Depressed nightmare recall may occur secondary to the REMS suppression know[n] to occur in patients with significant OSA.” The research appeared in the Feb. 15 edition of the Journal of Clinical Sleep Medicine. READ ABSTRACT

Improvement in LVEF Leads to Conversion from CSA to OSA in Heart Failure Patients
Canadian investigators who examined sleep studies and left ventricular ejection fraction (LVEF) in 98 heart failure patients with central sleep apnea (CSA) taking part in a large clinical trial find patients whose LVEF improved were more likely to spontaneously shift from mainly CSA to mainly obstructive sleep apnea. Eighteen of the patients converted, and among that group, a significantly greater increase in the LVEF was noted. The authors call for more study to examine this relationship. The study appears in this month’s European Respiratory Journal. READ ABSTRACT