Diabetes and the Association of Postoperative Hyperglycemia With Clinical and Economic Outcomes in Cardiac Surgery

Abstract

OBJECTIVEThe management of postoperative hyperglycemia is controversial and generally does not take into account pre-existing diabetes. We analyzed clinical and economic outcomes associated with postoperative hyperglycemia in cardiac surgery patients, stratifying by diabetes status.RESEARCH DESIGN AND METHODSMulticenter cohort study in 4,316 cardiac surgery patients operated on in 2010. Glucose was measured at 6-h intervals for 48 h postoperatively. Outcomes included cost, hospital length of stay (LOS), cardiac and respiratory complications, major infections, and death. Associations between maximum glucose levels and outcomes were assessed with multivariable regression and recycled prediction analyses.RESULTSIn patients without diabetes, increasing glucose levels were associated with a gradual worsening of outcomes. In these patients, hyperglycemia (≥180 mg/dL) was associated with an additional cost of $3,192 (95% CI 1,972 to 4,456), an additional hospital LOS of 0.8 days (0.4 to 1.3), an increase in infections of 1.6% (0.5 to 2.8), and an increase in respiratory complications of 2.6% (0.0 to 5.3). However, among patients with insulin-treated diabetes, optimal outcomes were associated with glucose levels considered to be hyperglycemic (180 to 240 mg/dL). This level of hyperglycemia was associated with cost reductions of $6,225 (−12,886 to −222), hospital LOS reductions of 1.6 days (−3.7 to 0.4), infection reductions of 4.1% (−9.1 to 0.0), and reductions in respiratory complication of 12.5% (−22.4 to −3.0). In patients with non–insulin-treated diabetes, outcomes did not differ significantly when hyperglycemia was present.CONCLUSIONSGlucose levels <180 mg/dL are associated with better outcomes in most patients, but worse outcomes in patients with diabetes with a history of prior insulin use. These findings support further investigation of a stratified approach to the management of patients with stress-induced postoperative hyperglycemia based on prior diabetes status.

Acute severe illness in diabetes patients: is tolerating hyperglycemia beneficial?

“…Apart from the different diabetes treatment, the opposite relationship between glycemia and outcome in the current study of Greco could be explained by a difference in preadmission glucose levels. Indeed, the HbA1c was significantly different between insulin-treated and non-insulin-treated diabetics, with a significantly higher HbA1c (or higher mean glucose levels) in insulin-treated diabetics (17).…”

“…In addition, if hyperglycemia would be advantageous in insulin-treated diabetics, one would expect that patients with at least two hyperglycemic measurements would perform better than patients with only one measurement in that range, which was apparently not the case. It is also unclear why the authors did not always correct for all baseline risk factors (17).…”

“…To study the relationship of glycemia with outcome, Greco et al further divided diabetics regarding the diabetes treatment they received (17). Whereas non-insulin-treated diabetics behaved similarly as non-diabetics, with worse outcomes when peak glycemia exceeded 180 mg/dL (10 mmol/L), insulin-treated diabetics apparently had a better outcome when peak glycemia exceeded that value.…”

“…In a recent issue of Diabetes Care, Greco and colleagues investigated the relationship between postoperative glucose levels and outcome after cardiac surgery (17). In patients without pre-existing diabetes mellitus and in patients with diabetes not treated with insulin, corrected for baseline risk factors, they found significantly worse outcomes when peak glycemia in the first 48 hours was above 180 mg/dL (10 mmol/L).…”

The Incidence of Acute Kidney Injury after Coronary Artery Bypass Surgery with or without Cardiopulmonary Bypass

“…Previous studies have shown that anaemia is more prevalent than other surgeries in cardiac surgery (24). Another problem following CABG is hyperglycaemia which is related to decreased operational outcomes in the long run and increased mortality and morbidity after CABG (25,26). Hyperglycaemia after CABG has been observed in the non-diabetic patients (27).…”