Sleep Apnea's Implications for Surgery

Delirium experienced after a surgical procedure may be related to sleep apnea

(RxWiki News) Feeling confused and losing consciousness after a surgery is no light matter - it can cause health problems later on. But if it's related to a treatable condition, that's good news.

A recently published small study has found a link between sleep apnea and delirium experienced by patients after a surgery. If the link is confirmed, better treatment of the apnea may reduce the likelihood of delirium.

"Get screened for sleep apnea prior to a major surgery."

Lead author Benjamin Flink, a student in the Duke School of Medicine, and fellow researchers studied 106 patients over the age of 65 who underwent total knee replacement to see what underlying medical conditions might relate to the patient's experiencing delirium immediately after the surgery.

Delirium occurs when a person experiences confusion and goes in and out of consciousness.

Previous research has found that patients who experience delirium after a surgery are at a higher risk for health issues and death immediately after surgery and even ten years down the road.

Patients with dementia, a nervous system or neurological disorder, alcoholism, depression or any serious psychiatric disorder were excluded from the study.

Of the 15 people undergoing the surgery who had sleep apnea, eight developed delirium within the first three days following the procedure - approximately 53 percent.

There were 19 others who developed delirium on the second or third day after surgery, but they were out of a total 91 patients who did not have sleep apnea, a rate of only 20 percent.

The researchers did not identify any other conditions that increased the likelihood that a patient would experience delirium after the surgery, and they adjusted their statistics to account for the patients' age, gender, weight and education level.

Because the number of people who had sleep apnea in the study was small, the researchers recommended a larger study to confirm their results.

The researchers also recommended that patients be screened for sleep apnea prior to a surgery.

"If the association between pre-existing sleep apnea and postoperative delirium discovered in this study is confirmed by a larger study, we may be able to prevent postoperative delirium by treating sleep apnea before and immediately after surgery," said senior author Madan Kwatra, Ph.D., an anesthesiology professor at Duke University Medical Center.

Although doctors are not sure what causes delirium after a surgery, one theory is that a patient is not getting enough oxygen before or just after a surgery. Another proposes that the cause is related to problems with a person's immune system.

The study appears in the April issue of Anesthesiology. The research was funded by a National Institutes of Health grant and the Department of Anesthesia at the Duke University Medical Center. No competing interests of authors were noted.

Review Date: 
March 30, 2012