EVALUATION OF OUTCOMES AND COMPLICATIONS IN PATIENTS WHO EXPERIENCE HYPOGLYCEMIA AFTER CARDIAC SURGERY.

OBJECTIVE: The objective of the study was to elucidate 30-day and long-term outcomes in patients experiencing postoperative hypoglycemia. METHODS: We conducted a retrospective review of patients who underwent cardiac surgery between September 4, 2007, and April 30, 2011, at Northwestern Memorial Hospital who had intensive treatment of hyperglycemia postoperatively. Of 1,325 patients, 215 experienced a hypoglycemic episode (blood glucose <70 mg/dL) within the first 3 postoperative days. A total of 198 were propensity-score (PS) matched to 363 patients without hypoglycemia. The analysis consisted of a comparison of 30-day cardiac outcomes and long-term mortality between those who experienced a hypoglycemic event and those who did not. RESULTS: Between patients who experienced hypoglycemia compared to those that did not, there were no significant differences in mean glucose values while on insulin drips (119.8 ± 33.5 mg/dL vs. 120.9 ± 30.5 mg/dL; P = .69) or subcutaneous insulin (122.0 ± 38.0 mg/dL vs. 127.2 ± 35.5 mg/dL; P = .11) or postoperative surgical complication rates (30-day mortality: 3.5% vs. 1.7%; complications (any): 40% vs. 42%; 30-day re-admissions: 13% vs. 13%; all cardiac complications: 35% vs. 31%; and all infections: 8% vs. 5%). Over an average of 5.1 ± 2.2 years following index surgery, there was higher all-cause mortality among those PS-matched who had experienced hypoglycemia compared to those who had not (log-rank P = .031), primarily due to those (n = 32) experiencing more than one episode of hypoglycemia. CONCLUSION: Postoperative hypoglycemia did not negatively impact immediate surgical complication rates but was associated with a significant risk of increased postoperative morbidity and long-term all-cause mortality in patients experiencing multiple episodes of hypoglycemia. ABBREVIATIONS: BG = blood glucose BMI = body mass index CARD = Cardiovascular Research Database HR = hazard rate PS = propensity score.

Comparison of glycemic and surgical outcomes after change in glycemic targets in cardiac surgery patients.

OBJECTIVE: To compare perioperative glycemic and long-term surgical outcomes in patients undergoing cardiac surgery before and after the recommended 2009 changes in inpatient glycemic targets. RESEARCH DESIGN AND METHODS: We performed a retrospective review of patients who underwent cardiac surgery between 4 September 2007 and 30 April 2011. Comparison was made of blood glucose (BG) outcomes 3 days after surgery, and 30-day cardiac outcomes before and after a change in insulin protocol that took place on 1 September 2009, which consisted of raising the glycemic targets during intravenous insulin infusions from 80-110 mg/dL (80-110 group) to 110-140 mg/dL (110-140 group). RESULTS: When compared with the 80-110 group (n = 667), the 110-140 group (n = 658) had higher mean postoperative BG levels during the intravenous insulin infusion (141 ± 15 vs. 121 ± 15 mg/dL, P < 0.001) and the subcutaneous insulin period (134 ± 24 vs. 130 ± 23 mg/dL, P < 0.001), and for 3 days postoperatively (141 ± 17 vs. 127 ± 15 mg/dL, P < 0.001). Fewer patients in the 110-140 mg/dL group experienced moderate hypoglycemia (BG <70 mg/dL) (177 vs. 73, P = 0.04). Severe hypoglycemia (BG <40 mg/dL) occurred in only one patient in the 80-110 group and three patients in the 110-140 group. There were no significant differences in mortality or surgical complication rates (with the exception of reintubation) between the groups. CONCLUSIONS: The higher glycemic target of 110-140 mg/dL resulted in similar mean glucose values, with significantly less hypoglycemia and no significant differences in mortality/morbidity compared with the more strict target of 80-110 mg/dL.