Predisposing Factors for Hypoglycemia and Its Relation With Mortality in Critically Ill Patients Undergoing Insulin Therapy in an Intensive Care Unit

BACKGROUND: Hypoglycemia is a common and the most important complication of intensive insulin therapy in critically ill patients. Because of hypoglycemia’s impact on the cardinal organs as a fuel, if untreated it could results in permanent brain damage and increased mortality. OBJECTIVES: In this study, we aim to evaluate the incidence of hypoglycemia, its risk factors, and its relationship with mortality in critically ill patients. PATIENTS AND METHODS: Five hundred adult patients who admitted to an intensive care unit (ICU) were enrolled in this study. A program of glycemic control with a target of 100 - 140 mg/dL was instituted. We used the threshold of 150 mg/dL for septic patients, which were monitored by point of care devices for capillary blood measurement. We detected hypoglycemia with a blood sugar of less than 50 mg/dL and with the detection of each episode of hypoglycemia, blood glucose measurement was performed every 30 minutes. RESULTS: Five hundred patients experienced at least one episode of hypoglycemia, almost always on the third day. Of 15 expired patients who had one hypoglycemia episode, the most common causes were multiple trauma and sepsis. Increases in the sequential organ failure assessment (SOFA) number augmented the hypoglycemia risk to 52% (P < 0.001). Moreover, in patients with acute kidney injury (AKI), the risk of hypoglycemia is 10 times greater than in those without AKI (RR: 10.3, CI: 3.16 - 33.6, P < 0.001). ICU admission blood sugar has a significant relationship with mortality (RR: 1.01, CI: 1.004 - 1.02, P < 0.006). Hypoglycemia increased the mortality rate twofold, but it was not significant (RR: 1.2, CI: 0.927 - 1.58, P = 0.221). CONCLUSIONS: Our results showed that the SOFA score, AKI, and hemoglobin A1c are the independent risk factors for the development of hypoglycemia and demonstrated that ICU admission blood glucose, Hba1c, and hypoglycemia increased the risk of death, but only ICU admission blood glucose is significantly related to increased mortality.