Nurse-Led Care for Sleep Apnea Passes Muster
By Michael Smith, North American Correspondent, MedPage Today
Published: March 06, 2009
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine.
ADELAIDE, March 6 -- A simplified model of care for obstructive sleep apnea led by nurses is as effective as the traditional physician-guided model, researchers here said. Action Points
--------------------------------------------------------------------------------
Explain to interested patients that obstructive sleep apnea is usually diagnosed and treated by specialist physicians using the resources of a sleep lab -- a model of care that is expensive and time-consuming.
Note that this study evaluated a simplified model of care, led by nurses, and found results equivalent to the traditional model.
In a randomized noninferiority trial, the two models had nearly equivalent results in terms of improvement on the Epworth Sleepiness Scale, according to Nick Antic, M.B.B.S., Ph.D., of the Adelaide Institute for Sleep Health, and colleagues.
The nurse-led model also cost $722 less per patient, Dr. Antic and colleagues reported in the March 15 issue of the American Journal of Respiratory and Critical Care Medicine.
"While we were not surprised at this finding," Dr. Antic said, "we were very pleased, as it indicates a robust new avenue for providing better access to sleep services for those with moderate-to-severe (obstructive sleep apnea) in a timely yet cost-effective fashion without sacrificing patient outcomes."
Dr. Antic and colleagues said they undertook the study because the prevalence of moderate-to-severe sleep apnea is likely to rise in lockstep with the epidemic of obesity.
At the same time, the traditional model of care -- involving specialist physicians and overnight polysomnography on at least two occasions -- is leading to a shortage of resources.
In this study, they compared the traditional model with a system in which patients referred to the sleep center were supervised by a specialist nurse.
Home autotitrating positive airway pressure machines were used for four nights to find the appropriate fixed pressure for continuous positive airway pressure (CPAP).
During the trial, the nurse dealt with CPAP complications and referred patients to a specialist physician as needed.
Patients were recruited for the trial from a group referred to three Australian sleep centers for possible obstructive sleep apnea. Those eligible had overnight home oximetry and were randomized if they had a greater than 2% dip in blood oxygen readings more than 27 times an hour.
All told, 195 patients were assigned to one of the two treatment arms and followed for three months. The primary outcome was change on the Epworth Sleepiness Scale, but researchers measured other outcomes, including general health, neurocognitive function, and patient satisfaction.
After three months, the researchers found, patients in the nurse-led arm had an average improvement of 4.02 on the sleepiness scale, compared with 4.15 in the physician-led arm.
The mean difference of -0.13 was within the preset margin of noninferiority, the researchers said.
There was also no significant difference in:
Average sleep latency as measured by the Maintenance of Wakefulness Test
Any of the quality of life indices
Adherence to CPAP
Executive neurocognitive function
In neurocognitive maze completion tests, the two groups exhibited no difference in the change from baseline.
At the end of the trial, the number of mazes completed in eight minutes fell by 2.1 and 1.2 in the nurse- and physician-led models, respectively. But the decline was accompanied, the researchers found, by a "marked reduction" in the number of errors -- 33% and 27%, respectively.
They wrote that "we believed it important for the specialist nurse to be able to cross-consult under circumstances in which they were uncertain about the management of the patient. Twelve of 100 patients had a sleep physician review as a result of unsatisfactory progress in model A. Nine of these reviews were a once-only consultation."
Once informed consent was provided, only 22% of patients met the inclusion/exclusion criteria. Dr. Antic and colleagues noted that the study drew from patients already thought to be at risk for sleep apnea, so that the diagnostic criteria might have to be adjusted to suit other settings.
They added that the benefits of nurse-led care may not generalize to a less severely-affected patient population.
They also noted that "it is possible that the favorable findings of the current study may have depended on the specific combination of diagnostic and therapeutic equipment used, and may not be replicated if different technologies are used."
The study was supported by the National Health and Medical Research Council of Australia. Oximeters were donated by Masimo, of Irvine, Calif., and CPAP equipment was loaned by ResMed, of Sydney, Australia. Dr. Antic reported financial links with Respironics, ResMed, and Masimo.
Primary source: American Journal of Respiratory and Critical Care Medicine
Source reference:
Antic NA, et al "A randomized controlled trial of nurse-led care for symptomatic moderate-severe obstructive sleep apnea" Am J Respir Crit Care Med 2009; 179: 501-508.
http://www.medpagetoday.com/Pulmonary/S ... ders/13156