BACKGROUND: Critical illness neuropathy (CINP) is defined as an acute and primary axonal motor and sensory neural disease occurring in critically ill patients leading to severe limb weakness as well as difficulty in weaning. It could co-exist with myopathy hence the term critical illness polyneuropathy and myopathy (CIPNM). The clinical presentation of critical illness polyneuropathy includes flaccid quadriplegia without affecting cranial nerves. It usually complicates the clinical course of a patient on mechanical ventilation with severe sepsis and MODS. The cornerstone in the diagnosis of neuromuscular disorders in the critically ill is the electrophysiological evaluation. Until recently the only possible way to affect the incidence was to reduce the risk factors. Hyperglycemia is associated with adverse outcomes, including increased mortality and CIPNM, in acutely ill patients.

OBJECTIVES: To evaluate the relevant literature and determine the effect of intensive insulin therapy (ITT) versus conventional insulin therapy (ITT) in preventing the occurrence of critical illness polyneuropathy and myopathy among critically ill patients.

SEARCH STRATEGY: The search was performed by means of MEDLINE, PUBMED, Ovid SP, Science Direct, and Cochrane library database limited to studies written in English using the words "randomized clinical trial", "intensive insulin therapy", "intensive insulin therapy in critical illness", "critical illness", "critical illness polyneuropathy", "critical illness myopathy", and "critical illness polyneuropathy and myopathy". The title and abstract of the studies were evaluated. The references of each study selected were screened to identify studies that were not included on electronic search. Key journals and textbooks were also searched. References mentioned in the textbooks were likewise reviewed.

SELECTION CRITERIA: Studies were chosen if they met the following inclusion criteria: the study was a randomized controlled trial; the study participants were adults; a critical care setting used; the intensive insulin therapy was defined by a target blood glucose concentration of 80-110mg/dl; the conventional insulin therapy was defined by a target blood glucose concentration 210mg/dl; studies that documented critical illness polyneuropathy and myopathy (CIPNM).

DATA COLLECTION & ANALYSIS: Two reviewers independently did validity assessment. Analysis of data was done by statistical packs Revman 5.0 from the Cochrane Collaboration.

MAIN RESULTS: The search resulted in recovery of 3 trials met the inclusion criteria. A total of 1,188 patients from the 3 randomized trials were evaluated. Five hundred forty six (546) to received intensive insulin therapy (ITT) in contrast the six hundred forty two (642) who received conventional insulin therapy (CIT). The analysis using the presence of electrophysiological evidence of CIP/CIM showed that the IIT group had a lower event rate (151/546 or 28%) as compared to the CIT group (263/642 or 41%). This resulted to a total odds ratio (OR) of 0.51 with the confidence interval fixed at 95%. The relative risk (RR) was computed at 0.68 with a number needed to treat (NNT) of 7.8

REVIEWERS' CONCLUSIONS: IIT is an effective therapy that could actually decrease the incidence of critical illness polyneuropathy and myopathy among critically ill patients.