Nondiabetic Cardiac Surgical Patients Benefit from Strict Glucose Control

Strict perioperative control of blood glucose levels in patients undergoing surgery is linked to a lower risk of postoperative renal impairment and failure, according to a new study.

Researchers from Onze-Lieve-Vrouw Hospital (Aalst, Belgium) retrospectively analyzed two groups of consecutive patients undergoing cardiac surgery with cardiopulmonary bypass between August 2004 and June 2006. In the first group, which contained 305 patients, no tight glycemic control was implemented. Insulin therapy was initiated at blood glucose levels higher than 150 mg/dl. In the group with tight glycemic control (745 patients), intra- and postoperative blood glucose levels were targeted between 80-110 mg/dl, using the Aalst glycemia insulin protocol. Postoperative renal impairment or failure was evaluated based on serum creatinine, glomerular filtration rate (GFR), and urinary output. The researchers used the Cleveland Clinic Severity Score to compare the predicted versus observed incidence of acute postoperative dialysis between groups.

The results showed that mean blood glucose levels in the Insulin group were lower compared to the control group, from re-warming on cardiopulmonary bypass onwards until intensive care unit (ICU) discharge. In nondiabetics, strict perioperative blood-glucose control was associated with a reduced incidence of renal impairment and failure, as well as a reduced incidence of acute postoperative dialysis. Thirty-day mortality was lower in the Insulin than in the control group, representing a 70% decrease in nondiabetics and 56.1% in diabetics. However, in patients that needed hemodialysis, tight glycemic control did not reduce mortality. The observed overall incidence of acute postoperative dialysis was adequately predicted by the Cleveland Clinic Severity Score in the Control group, but was lower than predicted in the Insulin group. The study was published on December 4, 2008, in Critical Care, a publication of BioMedCentral.

"The fact that relatively short-term tight glycemic control during and after cardiac surgery has such an impact on renal function and mortality, is new,” concluded lead author Patrick Lecomte, M.D., and colleagues. "Avoiding the need for renal replacement therapy is probably a key factor in reducing mortality. The observed 60% reduction in postoperative dialysis in our insulin group may have contributed to decreased mortality rates.”

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Onze-Lieve-Vrouw Hospital