Critical illness polyneuropathy and myopathy: a systematic review

Abstract

Critical illness polyneuropathy and critical illness myopathy are frequent complications of severe illness that involve sensorimotor axons and skeletal muscles, respectively. Clinically, they manifest as limb and respiratory muscle weakness. Critical illness polyneuropathy/myopathy in isolation or combination increases intensive care unit morbidity via the inability or difficulty in weaning these patients off mechanical ventilation. Many patients continue to suffer from decreased exercise capacity and compromised quality of life for months to years after the acute event. Substantial progress has been made lately in the understanding of the pathophysiology of critical illness polyneuropathy and myopathy. Clinical and ancillary test results should be carefully interpreted to differentiate critical illness polyneuropathy/myopathy from similar weaknesses in this patient population. The present review is aimed at providing the latest knowledge concerning the pathophysiology of critical illness polyneuropathy/myopathy along with relevant clinical, diagnostic, differentiating, and treatment information for this debilitating neurological disease.

Keywords: Guillain-Barré syndrome; NSFC grant; critical illness myopathy; critical illness polyneuropathy; intensive care unit; multiple organ failure; nerve regeneration; neural regeneration; neurodegenerative diseases; sepsis.

Figure 1

Pathogenesis of critical illness polyneuropathy (CIP) and myopathy (CIM). The pathogenesis of CIP and CIM is complex, involving microcirculatory changes, metabolic alterations, electrical abnormalities, and bioenergetic failure. They contribute independently, simultaneously, or synergistically to the pathogenesis of CIP and CIM. ROS: Reactive oxygen species.

Figure 2

Pathological classification of critical illness polyneuropathy (CIP) and myopathy (CIM).

Figure 3

Therapeutic strategies for critical illness polyneuropathy (CIP) and myopathy (CIM). Supportive measures include nutritional interventions, anti-oxidant therapies, hormone replacement, and immunoglobulins. Intensive insulin therapy improves blood glucose control, and independently reduces the incidence of CIP and CIM. Early rehabilitation combining mobilization with physiotherapy is also advisable.