Should All Inpatients Undergo Sleep Apnea Screening?

Key Point

Routine screening of hospitalized patients for sleep apnea can be made easier through use of a protocol; however, there are some drawbacks that should be taken into consideration.

CHICAGO—At a “pro” versus “con” debate at the American College of Chest Physicians’ 2007 Annual International Scientific Assembly, experts agreed that sleep apnea is underdiagnosed in inpatients and patients who undergo same-day surgery, but they questioned whether routine screening is a viable strategy to identify at-risk patients.

ROUTINE SCREENING IDENTIFIES AT-RISK PATIENT

Anne E. O’Donnell, MD, Associate Professor of Medicine at Georgetown University School of Medicine in Washington, DC, argued in favor of sleep apnea screening for all inpatients. She described guidelines for such screening developed by the American Society of Anesthesiologists and by the American Academy of Sleep Medicine but predicted that routine screening is unlikely to gain acceptance at an institution unless required by hospital regulatory authorities. She also noted that, so far, there is no clear evidence supporting standard approaches to treating patients who might be identified by such screening.

“The prevalence of sleep-disordered breathing is unknown in medically ill inpatients, and the feasibility and utility of screening inpatients are untested,” Dr. O’Donnell acknowledged. She remarked that oximetry is probably not a reasonable screening tool for inpatients, of whom many have multiple comorbidities.

In 2006, Georgetown University formed a multidisciplinary team to address the issue of inpatient sleep apnea. “Our goal was to identify at-risk patients who could then be appropriately monitored when they were given therapies, such as IV opiates, that might exacerbate their sleep-disordered breathing,” Dr. O’Donnell said.

The hospital’s quality improvement group drove the initiative after three significant events and one sentinel event—the latter of which involved an orthopedic patient with sleep apnea who used a continuous positive airway pressure (CPAP) device at home but was not recognized as having sleep apnea when admitted to the hospital. Review of 12,000 hospital discharge records for the prior year showed only 274 patients coded with sleep apnea at discharge. “You would expect at least twice as many patients to have sleep apnea in this number of discharges,” Dr. O’Donnell said.

Few of the patients with sleep apnea had been seen by the respiratory therapy department during their hospital stay, only “a tiny percentage” had undergone pulse oximetry monitoring, and a few had received significant dosages of opiates. Until that time, patients were not allowed to bring their own CPAP equipment to the hospital.

The Georgetown team developed an algorithm to be included in the nursing intake form in all units. Patients were asked if they had sleep apnea. For those who answered yes, the nurse contacted the respiratory care team to arrange for patients to use their own CPAP unit from home or one provided by the hospital.

Patients who answered no were administered a screening questionnaire and were assessed for their Flemons sleep apnea score. Patients with a score that exceeded 48 were identified as having or being at risk for sleep apnea and tagged with purple wristbands. Patients on IV opiates or patient-controlled analgesia were tagged and also placed on oximetry.

The result was that 281 of the 1,162 patients with data collected were identified as being at risk for sleep-disordered breathing.
“The Flemons score is clearly imperfect, but applying it raised awareness. Since we started this screening project, we have not had any sentinel events related to sleep-
disordered breathing, nor have we canceled any surgeries or procedures as a result of such screening,” Dr. O’Donnell said.

Obtaining accurate neck measurements has been a concern, Dr. O’Donnell observed. “The most common problem is to see a 17-inch neck documented as 17 centimeters, with the person taking the measurements sometimes using the wrong side of the tape,” she said. She also noted that poor acceptance of the system by ICU nurses has been a problem. House staff also has been slow to accept the program.

SCREENING NOT LIKELY TO INFLUENCE INPATIENT CARE

Barbara A. Phillips, MD, Professor of Medicine at the University of Kentucky in Lexington, largely agreed with Dr. O’Donnell but said that many of the underlying conditions that lead to hospitalization are also associated with sleep-disordered breathing, including type 2 diabetes mellitus, heart failure, renal disease, acute coronary symptoms, and recurrent ischemic stroke. “Sleep apnea is not rare in the hospital setting,” she pointed out.

Treating sleep apnea has some concrete benefits, though. Dr. Phillips said that CPAP can lower blood pressure, reduce cardiovascular risk, and improve diabetic control in such patients.

“Even in mild to moderate sleep apnea, CPAP treatment reduced the risk of cardiovascular events. People with untreated severe sleep apnea were much more likely to die than people who received sleep apnea treatment,” Dr. Phillips said.

Dr. Phillips noted that primary care physicians appear to be missing the diagnosis quite often.

“In a study of people ultimately diagnosed with sleep apnea, one-third had been getting sedating medications from their doctors—most of whom were not pulmonary or sleep doctors. It turns out that at least 10% of people with chronic fatigue syndrome actually have unrecognized sleep apnea, and most of these also have inspiratory flow resistance,” Dr. Phillips said.

She emphasized that there is an urgent need for better collaboration between anesthesiologists and surgeons to evaluate patients for possible sleep apnea well before surgery to allow preparation of a perioperative management plan.

“You are not going to cancel somebody’s surgery that is scheduled for tomorrow because you suspect sleep apnea when the patient is admitted the night before. You are not going to cancel surgery for a dissecting aortic aneurysm no matter how worried you are about the possibility of obstructive sleep apnea,” she said. “But there is little talk about what should happen to such patients after they leave the hospital.”

Screening of inpatients “in real life” would create some major logistical problems. Dr. Phillips described a trial by anesthesiologists who screened all patients preoperatively. About one quarter of the patients were identified by the screening examination as “at risk,” but confirmatory preoperative polysomnography was only done in a very small minority of those who were believed to be at risk.

“Data show that a majority of hospitalized patients have sleep-disordered breathing,” Dr. Phillips said. “I think that definitive diagnostic testing, including a history or a physical with oximetry and/or an empiric CPAP trial, should be applied to all high-risk patients. Patients should also be followed after discharge, which is probably where we are most likely to drop the ball.”           

—Janis Kelly

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