PURPOSE:Hyperglycemia is associated with increased mortality among Intensive Care Unit (ICU) patients. Trials on intensive insulin therapy targeting blood glucose (BG) levels of 4.4–6.1 mmol/L (80–110 mg/dL) have yielded mixed results, raising questions about the most appropriate target for BG control in the ICU. The purpose of this exploratory study is to determine the most appropriate BG target by identifying the BG threshold that is associated with increased mortality.
METHODS:Nested cohort of 523 patients admitted to a medical/surgical ICU who were randomized to receive either intensive insulin therapy (BG 4.4–6.1 mmol/L ) or conventional therapy (BG 10–11.1 mmol/L [180–200 mg/dL]). Patients were divided into six groups of equal number of patients based on the average daily BG levels. The ICU mortality, hospital mortality and ICU related complications were compared. A logistic regression model was used to determine the effect of BG on ICU related mortality. Using multivariate analysis we compared mortality below and above different BG thresholds of 0.1 mmol/L (2 mg/dL) increments.
RESULTS:By comparing the six groups, we identified BG ≥ 8.7 mmol/L (157 mg/dL) as a threshold above which the ICU mortality is increased. The ICU mortality for patients with BG ≥ 8.7 mmol/L compared with patients with BG level <8.7 mmol/L was 23.2% Vs 11.1% respectively. P= 0.0004. In multivariate analysis, BG ≥ 8.7 mmol/L was independently associated with increased ICU mortality, P=0.02, odds ratio (OR) 1.21 (1.03–1.42).The incidence of severe sepsis acquired in the ICU was higher in patients with BG ≥ 8.7 mmol/L, P=0.02, OR 1.17 (1.02–1.35). Using 0.1 mmol/L (2 mg/dL) increments in BG level, there was a consistent increase in mortality in patients with BG ≥ 8.2 mmol/L (148 mg/dL).
CONCLUSION:Using increasing BG thresholds, BG level of 8.2 mmol/L appears to have the best separation in mortality.
CLINICAL IMPLICATIONS:A target of blood glucose below 8.2 mmol/L is associated with reduced mortality and may be more appropriate than more strict BG targets.
DISCLOSURE:Ashraf Al-Tarifi, No Financial Disclosure Information; No Product/Research Disclosure Information