Mask reduces apnea risk after surgery

Respiratory complications immediately after surgery can be reduced if patients with obstructive sleep apnea are identified beforehand, according to research from Utah Valley Regional Medical Center.

It's as simple as using a continuous positive airway pressure (CPAP) mask in the first few minutes in the recovery room for those patients, said Dr. Douglas Ross and respiratory therapist Karl Ludwig.

The research began with a search for the roots of respiratory distress suffered by some patients in the recovery room following surgery, a time when patients are particularly vulnerable.

Examination of the records indicated about a third were caused by pulmonary embolism, a third by pain medication and the final third by "undiagnosed, unappreciated obstructive sleep apnea," Ross said. "We decided we needed to do something to prevent these adverse effects after surgery."

A literature review wasn't very helpful, said Ludwig, but they did find a questionnaire that "kind of worked" to help identify patients with obstructive sleep apnea. With permission from the questionnaire's authors, the UVRMC team made changes to come up with their own screening tool, which they're calling the "Modified Berlin Questionnaire."

They assigned point values to questions such as whether someone snores and how loudly. Loud enough to bother others? Are patients tired during their work times and waking hours? Do they have high blood pressure? They also measured height and weight because of an established link between sleep apnea and excess weight.

During surgery, patients are usually intubated to help them breathe, and the anesthesiologist monitors them. Right after, that breathing tube is removed, which starts the dangerous period for respiratory complications in the recovery room. Often the tube must be put back in, Ross said.

Post-surgical complications can include low oxygen levels that fail to rise, inability to control the airway, pneumonia, partial lung collapse and aspiration, Ludwig said.

For the study, 200 patients earmarked by the questionnaire as likely to have sleep apnea were randomly assigned to traditional treatment or to have the breathing tube replaced by a CPAP mask after surgery.