Higher insulin infusion rate but not 24-h insulin consumption is associated with hypoglycemia in critically ill patients

• Hypoglycemia is a serious complication of insulin therapy in the critically ill.
• We examine indices of insulin consumption on the occurrence of hypoglycemia.
• 24-h insulin consumption is not associated with hypoglycemia.
• Peak insulin infusion rate is associated with hypoglycemia.
• Risk of hypoglycemia was 4-times higher if insulin rate was more than 8 units/h.

AimsTo assess the association between insulin infusion rates, and 24-h insulin consumption on hypoglycemia in the intensive care unit (ICU).MethodsThis was a retrospective case–control study, conducted at an academic institution in the United States. Adult patients admitted to the ICU receiving intravenous insulin infusions for blood glucose control were included. Hypoglycemic (blood glucose <70 mg/dL) patients were matched 1:1 with non-hypoglycemic controls based on age, gender, and body mass index. Multivariable conditional logistic regression analyses were conducted to determine the effect of: (1) weight-adjusted insulin infusion rate (units/kg/h), (2) non-weight-adjusted insulin infusion rate (units/h), or (3) 24-h insulin consumption (units/day) on hypoglycemia.ResultsA total of 122 patients were included in the study (61 cases, 61 controls). Compared to those patients who received <0.05 units/kg/h, the odds of hypoglycemia was higher in those who received was ≥0.1 units/kg/h (OR 4.57, 95% CI 1.45–14.41, p = 0.010). Compared to those patients who received <4 units/h, the odds of hypoglycemia was higher in those who received was ≥8 units/h (4.17, 95% CI 1.18–14.75, p = 0.027). The risk of hypoglycemia did not increase with higher 24-h insulin consumption.ConclusionsHigher insulin infusion rates rather than 24-h insulin consumption may be associated with hypoglycemia in critically ill patients in the ICU.