Multimodal assessment of intensive care unit acquired weakness (ICU-AW) in stroke patients in the neurology intensive care unit

Intensive care unit acquired weakness (ICU-AW) is a common condition that causes difficulty in weaning from mechanical ventilation, increases morbidity and mortality. In this study, ICU-AW development in stroke patients in the intensive care unit was evaluated by electrophysiological studies, bioimpedance analysis (BIA), muscle biopsy, and mitochondrial complex activities and the correlation between these methods was investigated. Twenty-four stroke patients were included in the study. The patients were followed by serial nerve conduction studies and BIA. Muscle biopsy was performed on patients who were considered having critical illness myopathy/neuromyopathy (CINM) in electrophysiological studies. Muscle biopsy specimens were examined histochemically. Respiratory chain complex activities were analysed and compared to control group consisted of muscle tissues of patients who underwent orthopaedic surgery for various reasons. The frequency of ICU-AW was found to be 33%. Femoral motor nerve conduction, which has not been used in previous studies, was the best parameter in predicting the development of CINM. It was observed that CMAP duration remained relatively constant in the early period and started to increase later on. The muscle biopsies revealed type 2 muscle fiber atrophy. The respiratory chain complex activity analysis showed a prominent decrease in complex I similar to septic patients. This was the first study evaluating the development of ICU-AW in stroke patients by electrophysiological studies, muscle biopsy and respiratory chain complex activities together. Studying all these parameters in larger cohorts is essential for a better understanding of the pathogenesis of critical illness neuromyopathy and new treatment strategies.