Is critical illness neuromyopathy and duration of mechanical ventilation decreased by strict glucose control?

Strict glycemic control (SGC) is reported to have a beneficial effect on critical illness polyneuropathy/myopathy (CINM) and the duration of mechanical ventilation. The methodology used to diagnose CINM differs substantially in studies on this topic. This may influence the reported treatment effect. We reviewed literature on the effect of SGC on CINM and duration of ventilation by conducting a OVID Medline systematic electronic search of literature describing effects of SGC on occurrence of CINM and the effect of SGC on the duration of mechanical ventilation. A beneficial effect of SGC on CINM, diagnosed by needle myography, was reported in three studies. One of these studies showed that the incidence of weakness or failure to wean did not decrease by SGC, as the number of electrophysiological studies (EMG) ordered for these problems remained the same. Another study reported no improvement of muscle strength due to SGC. SGC reduced the duration of mechanical ventilation in three studies while six other studies did not report this beneficial effect. SGC seems to have a beneficial effect on CINM, but the reported risk reduction is likely to be an overestimation of the treatment effect due to the diagnostic methods used. Duration of mechanical ventilation may not be a reliable surrogate marker for CINM and a beneficial effect of SGC on this parameter has not been proven. We propose to use the recently developed diagnostic criteria for ICU-acquired weakness and critical illness neuromyopathy in future studies.