Ahead of Print: Tight Glycemic Control Reduces Infection
Background: Tight glycemic control (TGC) may improve outcomes in hyperglycemic neurosurgical patients. The adoption of TGC has been limited by lack of adequate data regarding optimal insulin delivery protocols and serum glucose concentration, and concerns regarding the risks of hypoglycemia.
Objective: This study was designed as a meta-analysis of outcomes to compare IIT (Intensive Insulin Therapy) and TGC with CIT (Conventional Insulin Therapy) and CGC (Conventional Glucose Control). The secondary objective was to determine retrospectively whether a particular glucose range correlates with better outcomes.
Methods: Using electronic databases, we retrieved all English language studies published between January 1997 and December 2010 reporting outcomes in neurological and neurosurgical patients as a function of glucose levels and insulin protocols. We conducted a meta-analysis around four outcome measures: infection, neurological outcome, hypoglycemia, and mortality. Effect sizes in each study were individually correlated with target IIT glucose levels. Individual studies were assessed for quality using the Jadad scale.
Results: Nine studies reporting on 1459 patients met the inclusion criteria. Five were restricted to neurosurgical patients. Four included neurological patients. In comparison to CGC, TGC lowered infection rates (OR: 0.59, 95% CI: 0.47-0.76, P<0.00001) and yielded better neurological outcomes (OR: 1.72, 95%CI:1.36-2.16, P<0.00001). Beneficial effects increased as glucose limits tightened and study quality improved (R2 > 0.9 for both). TGC resulted in a higher rate of hypoglycemic events (OR: 8.04, 95%CI:4.85-13.31, P<0.00001). Mortality was not affected.
Conclusion: TGC reduced infection risk and improved neurological outcome despite increased rates of hypoglycemic events. An optimal target for serum glucose concentrations could not be determined.
From: Tight Glycemic Control Reduces Infection and Improves Neurological Outcome in Critically Ill Neurosurgical and Neurological Patients by Ooi et al.