Post-Surgery Stroke Risk Increases as Blood Pressure Levels Fall

Newswise — Occurring in only 0.1 percent to 3 percent of all noncardiac surgeries, the risk for stroke development following surgery remains a complication of concern for patients. New research reveals that patients who experience lower blood pressure during noncardiac surgery may face an increased risk of developing a stroke post-surgery.

Researchers from University Medical Center Utrecht, Netherlands, investigated the possible role of various levels of blood pressure during surgery in the occurrence of stroke after surgery. Stroke following surgery is most often an ischemic or embolic stroke due to the release of particles during surgery obstructing a blood vessel to the brain.

"The investigation focused on patients in procedures other than cardiac, neurological or carotid surgeries, which already carry a known increased risk for post-surgical stroke development," said Cor J. Kalkman, M.D., Ph.D., University Medical Center Utrecht, Netherlands.

The study included over 30,000 patients undergoing surgery from January 2002 to March 2008. 41 patients who experienced a stroke within 10 days after surgery were selected and matched with 164 control patients who did not experience a stroke.

After adjustment for known stroke risk factors of age, gender, history of diabetes, hypertension and previous stroke, researchers found a trend toward a higher risk for stroke after surgery for patients who experienced lower blood pressure levels during surgery.

"While these findings are of clinical importance because blood pressure is a controllable factor, the results should be interpreted with extreme caution due to the small numbers of stroke patients and the complex interaction of patient and surgical factors on the risk of stroke following surgery," said Dr. Kalkman. "Especially for sick or elderly patients who may be less tolerant to low blood pressure levels the results indicate that tight blood pressure control and monitoring may be the next step to prevent excess strokes."

For all groups of patients, a history of previous stroke remains the main risk factor for developing a stroke after surgery.

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