Risk Factors for Polyneuromyopathy of Critical Illness

Although abnormalities of the neuromuscular system complicating critical illness were recognized about 25 years ago [1], their clinical importance has only become appreciated over the last 15 years [2]. Clinical and paraclinical signs of critical illness neuromuscular abnormalities (CIMNA) and their outcomes have been described in many prospective cohort studies which we systematically reviewed recently [3]. Although weakness is the cardinal clinical sign, this sign was comprehensively assessed in only two of eight cohort studies [4, 5], and found to occur with a frequency of 36 and 70%, respectively. Electrophysiologic abnormalities involving the sensory or motor nerve, neuromuscular junction and/or muscle have been evaluated in seven studies, with a rate of abnormal findings up to 90% [6]. Muscle biopsy has been less frequently and less systematically performed, but has revealed a high rate of histologic abnormalities in patients with suspected CINMA.