The potential impact of admission insulin levels on patient outcome in the intensive care unit.

BACKGROUND: Blood levels of insulin in patients with critical illness at admission to the intensive care unit (ICU) and its association with in-hospital mortality are not fully defined. Our objective was to determine this association in a cohort of patients with critical illness who attended in a mixed ICU. METHODS: Prospective cohort was nested in a randomized clinical trial conducted in a 12-bed mixed ICU in a tertiary hospital in Medellin (Colombia). One hundred sixty consecutively admitted patients, 15 years or older, were analyzed. Blood insulin and blood glucose levels were measured at admission to the ICU, as well as Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores. A logistic regression model was created with in-hospital mortality as the outcome. RESULTS: In-hospital mortality was 57 (35.6%) of 160. Survivors had lower Acute Physiology and Chronic Health Evaluation II (median, 13 vs. 17) and lower insulin levels (median, 6.5 vs. 9 µU/mL) than did nonsurvivors. More women than men died (27 [48.2%] of 56 vs. 30 [28.8%] of 104), and 39% of the deaths (n = 22) occurred in patients with sepsis. Patients with insulin levels greater than 15 µU/mL had a higher mortality rate compared with patients with values of 5 µU/mL to 15 µU/mL (odds ratio, 3.57; 95% confidence interval, 1.18-10.8). CONCLUSION: At admission to the ICU, patients with critical illness showed hyperglycemia and relatively decreased insulin levels. High levels of insulin were independently associated with in-hospital mortality in this study population. LEVEL OF EVIDENCE: Prognostic study, level II.

Strict glycaemic control in patients hospitalised in a mixed medical and surgical intensive care unit: a randomised clinical trial.

INTRODUCTION: Critically ill patients can develop hyperglycaemia even if they do not have diabetes. Intensive insulin therapy decreases morbidity and mortality rates in patients in a surgical intensive care unit (ICU) and decreases morbidity in patients in a medical ICU. The effect of this therapy on patients in a mixed medical/surgical ICU is unknown. Our goal was to assess whether the effect of intensive insulin therapy, compared with standard therapy, decreases morbidity and mortality in patients hospitalised in a mixed ICU. METHODS: This is a prospective, randomised, non-blinded, single-centre clinical trial in a medical/surgical ICU. Patients were randomly assigned to receive either intensive insulin therapy to maintain glucose levels between 80 and 110 mg/dl (4.4 to 6.1 mmol/l) or standard insulin therapy to maintain glucose levels between 180 and 200 mg/dl (10 and 11.1 mmol/l). The primary end point was mortality at 28 days. RESULTS: Over a period of 30 months, 504 patients were enrolled. The 28-day mortality rate was 32.4% (81 of 250) in the standard insulin therapy group and 36.6% (93 of 254) in the intensive insulin therapy group (Relative Risk [RR]: 1.1; 95% confidence interval [CI]: 0.85 to 1.42). The ICU mortality in the standard insulin therapy group was 31.2% (78 of 250) and 33.1% (84 of 254) in the intensive insulin therapy group (RR: 1.06; 95%CI: 0.82 to 1.36). There was no statistically significant reduction in the rate of ICU-acquired infections: 33.2% in the standard insulin therapy group compared with 27.17% in the intensive insulin therapy group (RR: 0.82; 95%CI: 0.63 to 1.07). The rate of hypoglycaemia (< or = 40 mg/dl) was 1.7% in the standard insulin therapy group and 8.5% in the intensive insulin therapy group (RR: 5.04; 95% CI: 1.20 to 21.12). CONCLUSIONS: IIT used to maintain glucose levels within normal limits did not reduce morbidity or mortality of patients admitted to a mixed medical/surgical ICU. Furthermore, this therapy increased the risk of hypoglycaemia. TRIAL REGISTRATION: clinicaltrials.gov Identifiers: 4374-04-13031; 094-2 in 000966421.