Implementing intensive insulin therapy in daily practice reduces the incidence of critical illness polyneuropathy and/or myopathy

Introduction

In two randomised controlled trials (RCTs) on the effect of intensive insulin therapy (IIT) in a surgical ICU (SICU) and a medical ICU (MICU), IIT reduced the incidence of critical illness polyneuropathy and/or myopathy (CIP/CIM) and the need for prolonged mechanical ventilation (MV ≥ 14 days). Here we investigated whether these effects are present in daily practice when IIT is implemented outside a study protocol.

Methods

We retrospectively studied all electronically available electrophysiological data (electroneuromyography (ENMG)) from patients in the SICU and MICU before and after implementation of IIT in routine practice (omitting data obtained during the two RCTs). All ENMGs were performed because of clinical weakness and/or weaning failure. As in the RCTs, CIP/CIM was diagnosed by the presence of abundant spontaneous electrical activity (fibrillation potentials or positive sharp waves). Baseline and outcome variables were compared using Student's t test, chi-square test or Mann–Whitney U test when appropriate. The effect of implementing IIT on CIP/CIM and prolonged MV were assessed using univariate analysis and multivariate logistic regression analysis (MVLR) correcting for baseline and ICU risk factors.

Results

ENMGs were performed in 193 long-stay ICU patients before and 494 after implementing IIT. This population comprised 4.6% of all patients before and 5.6% after IIT implementation in the MICU and 4.0% before and 3.9% of all patients after IIT implementation in the SICU. With IIT, mean glycemia was significantly lowered (median 142 (130–153) to 106 mg/dl (100–113)). IIT implementation significantly reduced ENMG diagnosis of CIP/CIM in this population (71.6% to 48.7% (P < 0.0001)). MVLR identified implementing IIT as an independent protective factor (P < 0.0001, OR = 0.24 (95% CI = 0.14–0.43)). MVLR confirmed the independent protective effect of IIT on prolonged MV (P = 0.03, OR = 0.55 (95% CI = 0.31–0.95)). This effect was explained by the reduction in CIP/CIM (P = 0.009, OR = 1.13 (95% CI = 1.65–2.42)).

Conclusion

Implementing IIT in daily practice evokes a similar beneficial effect on neuromuscular function, as observed in two RCTs. IIT significantly improves glycemic control and significantly and independently reduces the electrophysiological incidence of CIP/CIM. This reduction explains the beneficial effect of IIT-prolonged MV.