Continuous positive airway pressure machines (CPAP) are standard equipment for patients with obstructive sleep apnea (OSA), and they are no doubt effective. Yet patient compliance remains a problem. A number of CPAP accessories have come to market in an effort to better a patient’s experience, improving compliance and therapy effectiveness. And while hose covers, mask straps, and nasal pads have helped improve patient comfort while using CPAP, a number of treatment options are being studied to see if there is an alternative or adjunct treatment for OSA that could provide patients with more treatment choices.
IT’S WHAT YOU WEAR
French researchers recently found that the simple act of wearing compression stockings is effective in improving OSA in patients with chronic venous insufficiency (CVI), a condition that occurs when a patient’s veins cannot pump enough oxygen-depleted blood back to the heart. CVI occurs most often in the veins of the legs.
According to the researchers, the use of compression stockings reduced daytime fluid accumulation in the legs, which in turn reduced fluid flow into the neck during sleep. As a result, the number of apneas and hypopneas was reduced by a third, according to the study, titled “Attenuation of Obstructive Sleep Apnea by Compression Stockings in Subjects with Venous Insufficiency,” recently published in the American Journal of Respiratory and Critical Care Medicine.1
In active people, fluid accumulation in the legs is counteracted by leg muscle contractions that squeeze the veins. Prolonged sitting, however, can prevent this process, shifting the accumulated fluid in the legs rostrally overnight. This shift results in fluid accumulation in neck tissue and is thought to increase apneic events by increasing the volume of the tissue, leading to repetitive collapse of the pharynx during night breathing. In otherwise healthy subjects who have heart failure or hypertension, the amount of this overnight rostral fluid shift is strongly correlated with the degree of overnight increase in neck circumference and the number of apneas and hypopneas per hour of sleep.
“We hypothesized that the fluid accumulation that occurs in the legs of people with chronic venous insufficiency would be reduced by wearing compression stockings, and that the reduction in the fluid would also reduce the shift of that fluid to the neck during the night,” said Stefania Redolfi, MD, from the University of Brescia in Italy.
For the study, 12 patients with CVI were randomly assigned to either 1 week of wearing compression stockings during the day or to a 1-week control period without compression stockings. Once participants completed the first week, they were assigned to the other arm of the study. Each participant underwent polysomnography (PSG) and a baseline reading of overnight changes in leg fluid volume and neck circumference, as well as readings after completing each arm of the study.
Compared to the control period, patients saw a 62% reduction in overnight leg fluid volume change and a 60% reduction in overnight neck circumference increase, as well as a 36% reduction in the number of apneas and hypopneas per hour of sleep at the end of the compression stocking period. The findings show that among CVI patients, overnight rostral fluid displacement is a mechanism of disease for OSA and that the effect of compression stockings on OSA is based on counteracting this fluid displacement. According to Redolfi, prevention of this dependent fluid reduction could constitute a new therapeutic approach to OSA.
“These findings are what we expected, but the extent to which simply wearing compression stockings reduced apnea in just 1 week was not expected,” added Redolfi. “It would be very interesting to see whether the wearing of the stockings over longer periods would have an even greater effect. Whether prevention of overnight rostral fluid displacement can attenuate OSA in other patient populations is an important issue that remains to be addressed in future studies.”
IT’S HOW YOU SLEEP
From additional clothing to a different kind of pillow, Canadian researchers recently found that the addition of a novel pillow could help OSA patients better maintain a nonsupine sleep position. A supine position is associated with snoring, as well as worse OSA, and avoiding such a position may be desirable in such patients, according to the authors of this study, titled “Efficacy of the Somnaform Pillow in Maintaining Non-Supine Sleep.”
While the classic “tennis ball technique” has been recommended to keep patients from sleeping in a supine position, the reality is it does nothing to improve patient comfort or compliance with OSA therapy while trying to get a good night’s sleep. For this study, the researchers specifically used the Somnaform pillow—designed to help patients avoid the supine position—in their small pilot study to determine whether it prevents patients with supine-dependent OSA from moving into that sleep position.
To participate, patients had to have 5 to 40 apnea-hypopnea index (AHI) events per hour: AHI-supine/AHI-nonsupine >2; AHI-nonsupine <10 events per hour; and time supine >25% of total sleep time upon an initial PSG. The eight participants meeting this criteria then had a second PSG, during which they were instructed to avoid supine sleep. For half of the PSG, participants used a standard pillow; for the other half of the PSG, they used the Somnaform pillow. A technician determined body position using video monitoring.
The findings, also published in the American Journal of Respiratory and Critical Care Medicine,2 show that while using the Somnaform pillow, six of the eight participants, or 75%, completely avoided supine sleep. While using the standard pillow, only two of the eight participants (25%) managed to completely avoid a supine sleep position.
The researchers concluded that the Somnaform pillow is more effective than a standard pillow at preventing supine sleep in OSA patients. While the researchers point out that additional studies are needed to determine the effect of the Somnaform pillow on objectively measured snoring and on OSA, such a simple addition to an OSA patient’s sleep environment could have an immediate impact on their OSA and their health.
Meanwhile, Brazilian researchers have found an option requiring no additional tools. They found that simply elevating bedhead position can improve OSA. The discovery of such an easy adjustment to patient sleep habits could provide patients with the incentive to incorporate OSA treatment into their sleep routine.
While previous studies had suggested a correlation between bedhead elevation and stabilization of the upper airway in OSA patients, the researchers in this study, titled “The Influence of Bedhead Elevation on Patients with Obstructive Sleep Apnea,”3 which also appeared in the American Journal of Respiratory and Critical Care Medicine, sought to specifically test the impact of slope of the bedhead in patients with OSA and see if it could work as a possible therapy option.
The cross-sectional study enrolled 17 patients—eight of whom were men, aged 51.31 ± 9.76, with a body mass index of 30.86 ± 5.49. Over the course of 2 weeks, participants underwent a standard PSG at baseline and again while elevating the head at 15 cm, a 30-degree inclination.
The researchers found that compared to the baseline PSG, head elevation resulted in significant improvements, including reduction in AHI total, NREM AHI, number of respiratory events, number of hypopneas, duration of snoring percentage and snoring in minutes, hypopnea index, and REM sleep latency. In addition, the minimum oxygen saturation showed a trend toward improvement.
While the research team notes that additional studies with more patients are needed to confirm the “real benefits” of varying degrees of slope on OSA, this study shows that the elevation of the head at 30 degrees significantly reduces OSA, which, the researchers write, “is a simple measure that may help patients awaiting diagnosis or treatment.”
All in all, research into such supplemental treatment options provides an opportunity for a breakthrough in OSA treatment that could give patients choices when it comes to finding what is best for their lives and their health.
Mohammed Quadri, RPSGT, is project coordinator of clinical trials at the Institute of Sleep and Wake Disorders, Hackensack University Medical Center, Hackensack, NJ. He can be reached at [email protected] The author acknowledges the assistance of Susan Zafarlotfi, PhD, and Lauren Dempsey, RPSGT.
- Redolfi S, Arnulf A, Pottier M, et al. Attenuation of obstructive sleep apnea by compression stockings in subjects with venous insufficiency [published online ahead of print August 11, 2011]. Am J Respir Crit Care Med. doi:10.1164/rccm.201102-0350OC.
- Li C. Efficacy of the Somnaform pillow in maintaining non-supine sleep. Am J Respir Crit Care Med. 2011;183:A2733.
- Souza Filho AJ, Souza FJFB, Lorenzi-Filho G. The influence of bedhead elevation on patients with obstructive sleep apnea. Am J Respir Crit Care Med. 2011;183:A2732.