Surgery Might Be Risky for People With High Blood Sugar
Diabetics with uncontrolled blood sugar levels may want to get them back to normal before going under the knife. A new study suggests that people with the highest levels have more than six times the risk of developing potentially fatal blood clots in their lungs following surgery. The study will be presented today at the annual meeting of the American Society of Anesthesiologists in Chicago.
Researchers at the Jefferson Medical College of Thomas Jefferson University in Philadelphia examined the records of more than 6,500 patients who had had hip or knee replacement surgery at Thomas Jefferson University Hospital and found that those who had blood sugar levels over 250 milligrams/deciliter before surgery had a greater risk of developing blood clots than a control group of surgical patients with normal glucose levels of below 125 mg/dl. (Blood glucose screenings are routinely performed before surgery.) About 11 percent of the diabetic patients with the highest blood sugar levels developed a pulmonary embolismwhich occurs when blood clots in leg veins break off and travel to the lungcompared with 2 percent of the healthy group. None of these patients died, though the condition can be deadly.
"This was an unexpected result," says study leader Boris Mraovic, an assistant professor of anesthesiology at Jefferson Medical College. The researchers controlled for body weight, the use of blood thinners, and a patient's previous history of blood clots, all of which could have affected the results. High blood sugar levels appear to increase clotting factors in the blood, which makes the blood thicker and more likely to form clumps. Studies suggest that one third of surgery patients have elevated blood sugar levels due to uncontrolled diabetes or presurgery stress.
This new study adds to a growing body of evidence about risks to surgical patients with high blood sugar, including greater danger of infections, renal failure, and even death. Despite this, Mraovic says, hospitals don't have standards in place for controlling blood sugar levels before surgery, and doctors usually don't delay surgery for this reason. His advice? Patients should take matters into their own hands. "Check your blood test results before surgery. If your blood sugar is high, ask your doctor if you can postpone surgery until it's within a normal range."