Necrotizing myopathy in critically‐ill patients

TLDR

Skeletal muscle wasting is common in critically‑ill patients, attributed to catabolic fibre atrophy and neuropathy, and necrosis likely arises from multifactorial causes including ischemia and sepsis. This study describes the occurrence of a necrotizing myopathy in 15 of 31 critically‑ill patients who underwent percutaneous tibialis anterior muscle biopsies. Percutaneous tibialis anterior biopsies were performed on 31 critically‑ill patients, revealing necrotizing myopathy in 15 cases. Necrotizing myopathy was observed in 15 of 31 patients, with most cases showing isolated fibre necrosis, 5 of 12 serial biopsies demonstrating progressive necrosis up to 95 % of fibres, additional infarction or staphylococcal vasculitis in single cases, type‑1/type‑2 fibre atrophy in 12 cases, myoglobin‑containing casts in renal tubules in 5 of 7 cases, and the necrosis likely contributed to weakness, complicated biochemical interpretation, and renal failure.

Abstract

Skeletal muscle wasting is commonly observed in critically-ill patients and has been attributed to catabolic fibre atrophy and to neuropathy. This study describes the occurrence of a necrotizing myopathy in 15 out of 31 critically-ill patients who had percutaneous biopsies taken from the tibialis anterior muscles. While most cases showed necrosis of isolated fibres, 5 of the 12 patients who had serial biopsies showed progressive necrosis of up to 95 per cent of the fibres. One other case showed infarction and one case had staphylococcal vasculitis. Atrophy of type 1 and/or type 2 fibres was documented by morphometry in 12 cases. Myoglobin-containing casts were demonstrated immunohistochemically in renal tubules on either biopsy or necropsy material in 5 out of 7 cases. The presence of muscle necrosis was a clinically unexpected finding which may contribute to weakness, complicate the interpretation of tissue biochemistry and energy balance studies, and potentiate renal failure. The necrosis is probably multifactorial in origin, with ischaemia and sepsis contributing factors.