February 2010

Notes from the Section

• The Winter issue of out section Bulletin is ONLINE now, with lots of information for sleep RTs, including an overview of OSA and a look at commercial truck drivers and their risk for the condition.
• Kudos to Patti Coogan, RRT, RPSGT, for passing the RPSGT exam in December of last year. Patti currently works in the respiratory therapy department and Sleep Center at Crouse Hospital in Syracuse, NY. (If you have a “kudos” to report, E-MAIL it to Section Chair Tony Stigall.)

Contaminated Water Leads to Lingering Infection
Sleep professionals warn their CPAP patients to use distilled water in their machines, and most patients follow through with that advice. A case report featured in the December issue of the Southern Medical Journal illustrates the importance of this precaution. Researchers outline the case of a woman who had been using CPAP for sleep apnea at home for a couple of years with no problem. However, when she traveled to a vacation home in a remote area, she forgot to bring distilled water and instead used tap water that came from a well located a few miles away. The well water was contaminated with a toxic bacterial compound called endotoxin that caused a lingering inflammatory disease of the lungs in the patient. While noting that city tap water would be unlikely to cause such a problem, the authors write, “We do believe that caution is warranted in CPAP humidification using tap water from wells in remote locations.” READ PRESS RELEASE

Residual Sleep Apnea Similar for Center, Home Testing
Irish researchers looked at the clinical implications, predictors, and patterns of residual sleep apnea on CPAP treatment in 61 patients with moderate-to-severe OSA who were randomly assigned to standard CPAP titration during polysomnography (PSG) or ambulatory titration using auto-CPAP and home sleep testing. Results showed 15 patients had residual sleep apnea (AHI>10/h on CPAP), with similar proportions in the PSG and ambulatory groups. Compliance to CPAP and other outcomes were worse in the residual sleep apnea patients. The study was published in the Jan. 16 Epub edition of Sleep Medicine. READ ABSTRACT

OSA and the Neural Respiratory Drive
According to German investigators, people with OSA require specific and increased levels of neural respiratory drive to maintain ventilation during sleep. They arrived at that conclusion after subjecting 21 OSA patients and 21 healthy controls to respiratory muscle testing and polysomnography. Among the findings:

• Neural respiratory drive as measured by the electromyogram of the diaphragm (EMG(di)) was elevated in the obese OSA patients, awake and supine (13.1(5.6)%max), compared to normal subjects (mean (SD) 8.1(2.3)%max.
• During unobstructed breathing in sleep (stage N2) normal subjects had an EMG(di) of 7.7(3.9) compared to 22.8(19.2)%max in the OSA group.
• Prior to airway occlusion, EMG(submandibular) and EMG(di) dropped markedly, then increased progressively following occlusion to their highest levels at airflow onset.

The study appeared in the Jan. 28 Epub edition of Respiratory Physiology & Neurobiology. READ ABSTRACT

REM versus NREM SDB: Affect on Sleepiness, QOL, and Sleep Maintenance
How does rapid eye-movement (REM) predominant sleep disordered breathing (SDB) affect sleepiness, quality of life, and sleep maintenance when compared to non-REM (NREM) SDB? Boston University School of Medicine investigators set out to answer that question in a study involving 5,649 people taking part in the Sleep Heart Health Study. They quantified SBD using a polysomnographically derived apnea-hypopnea index in REM (AHIREM) and AHINREM. Sleepiness, sleep maintenance, and quality of life were quantified using standard measures. After analyzing the results, the authors conclude, “In a community-based sample of middle aged and older adults, REM-predominant sleep-disordered breathing is not independently associated with daytime sleepiness, impaired health-related quality of life or self-reported sleep disruption.” The researchers published their findings in the Jan. 21 Epub edition of the American Journal of Respiratory and Critical Care Medicine. READ ABSTRACT