Carla Carr knew she felt tired a lot, but never suspected sleep apnea. The Fort Gibson, Okla., woman said she'd never been diagnosed, although she'd often be awakened by her husband when he'd catch her not breathing during sleep.
Carr, 43, was identified as being at high risk for obstructive sleep apnea (OSA) just before undergoing nine-hour surgery at Barnes-Jewish Hospital in February.
That knowledge helped ensure she had the proper safety mechanisms and monitoring in place during her hospital stay.
Barnes-Jewish Hospital has begun screening its surgery patients for obstructive sleep apnea — something that hasn't been on hospitals' radar screen — after a devastating complication in another surgery patient three years ago.
A healthy 40-year-old patient who had undergone successful surgery for a minor injury stopped breathing, went into a persistent vegetative state, and eventually died. Doctors suspected he had an undiagnosed case of OSA.
Life or death diagnosis
"Most people think about the heart pre-surgery, but not sleep apnea affecting surgery," said Kevin Finkel, a Washington University anesthesiology resident at Barnes-Jewish.
Finkel was the lead author of an article about the hospital's initiative that will be presented at the American Society of Anesthesiologists' annual meeting next month.
Last year, the ASA approved practice guidelines for managing surgery patients with OSA.
While recommendations for safer outcomes are nothing new, it's difficult getting medical professionals to adopt and translate them into better practice, said Dr. Robert Caplan, a Seattle anesthesiologist who oversees the scientific development of practice guidelines for the ASA.
"Washington University learned from an episode in their institution, and used that as a stepping stone to make it part of routine care," Caplan said.
"They're one of the finest medical centers in the U.S. and world. They're really stepping out and serving as an important role model recognizing this risk and taking specific steps to manage it.
"They're hardwiring their lessons into protocol that gives us safer and better outcomes."
Obstructive sleep apnea is characterized by episodes of stopped breathing during sleep.
Normally, low levels of oxygen and high levels of carbon dioxide in the blood arouse the sleeper with apnea.
But an anesthetic, or powerful pain medicine after surgery may interfere with the protective mechanism and prevent the person from waking up, resulting in respiratory arrest, said Dr. Michael Avidan, Barnes-Jewish's division chief of cardiothoracic anesthesia and intensive care.
The hospital set up a task force to identify surgical patients with sleep apnea and modify their care to ensure their safety.
23 percent of patients had apnea
At the same time, a hospital research team, led by Finkley, studied the extent of sleep apnea in surgery patients. The team discovered that an alarmingly high 23 percent had sleep apnea, and 76 percent of them had not previously been diagnosed.
From December 2005 through June the hospital screened 2,500 surgery patients, including Carr, with a questionnaire that ranked their risk for OSA as high, medium or low. High-risk patients were sent home with a device worn on the head during sleep that would confirm a diagnosis.
The high-risk patients were flagged with purple wrist bracelets and on their chart to alert every caregiver in the system — from transporter to anesthesiologist — to monitor them carefully and take specific steps to ensure their safety.
Those included using fewer drugs that suppress the arousal response, positioning patients on their side, and monitoring the patients as they slept for periods of apnea or lowered blood-oxygen levels.
Avidan said the protocol may set national standards for improving the safety of surgery patients with sleep apnea.
Obesity is a major risk factor of OSA, as soft tissue crowding in the throat leads to an airway collapse. Males over 40 are especially at risk.
The hospital's preliminary study results were published in the July-August issue of Sleep Review. A second study will look at how surgery affects sleep apnea patients.
Caplan of ASA couldn't say what percentage of hospitals, if any, screen surgery patients for sleep apnea, but he said awareness of the problem is increasing.