Association of intraoperative hyperglycemia and postoperative outcomes in patients undergoing non-cardiac surgery: a multicenter retrospective study

BACKGROUND: While pre and postoperative hyperglycemia is associated with increased risk of surgical site infection, myocardial infarction, stroke and risk of death, there are no multicenter data regarding the association of intraoperative blood glucose levels and outcomes for the non-cardiac surgical population. METHODS: We conducted a retrospective cohort study from the Michigan Surgical Quality Collaborative, a network of 64 hospitals that prospectively collects validated data on surgical patients for the purpose of quality improvement. We included data for adult general, vascular, endocrine, hepatobiliary, and gastrointestinal operations between 2013 and 2015. We assessed the risk-adjusted, independent relationship between intraoperative hyperglycemia (glucose > 180) and the primary outcome of 30-day morbidity/mortality and secondary outcome of infectious complications using multivariable logistic regression modelling. Post hoc sensitivity analysis to assess the association between blood glucose values ≥250 mg/dL and outcomes was also performed. RESULTS: Ninety-two thousand seven hundred fifty-one patients underwent surgery between 2013 and 2015 and 5014 (5.4%) had glucose testing intra-operatively. Of these patients, 1647 patients (32.9%) experienced the primary outcome, and 909 (18.1%) the secondary outcome. After controlling for patient comorbidities and surgical factors, peak intraoperative glucose > 180 mg/dL was not an independent predictor of 30-day mortality/morbidity (adjusted OR 1.05, 95%CI:0.86 to 1.28; p-value 0.623; model c-statistic of 0.720) or 30-day infectious complications (adjusted OR 0.93, 95%CI:0.74,1.16; p 0.502; model c-statistic of 0.709). Subgroup analysis for patients with or without diabetes yielded similar results. Sensitivity analysis demonstrated blood glucose of 250 mg/dL was a predictor of 30-day mortality/morbidity (adjusted OR: 1.59, 95% CI: 1.24, 2.05; p < 0.001). CONCLUSIONS: Among more than 5000 patients across 64 hospitals who had glucose measurements during surgery, there was no difference in postoperative outcomes between patients who had intraoperative glucose > 180 mg/ dL compared to patients with glucose values ≤180 mg/ dL.