Table 1 Causes of myopathy associated with respiratory failure

Inflammatory

Electrolyte disorders

Polymyositis, dermatomyositis

Hypokalemia

Inclusion body myositis

Hypophosphatemia

Systemic lupus erythematosus, rheumatoid arthritis, Sjogren’s Syndrome, Overlap Syndromes

Viral myositis

Endocrine

Drug/toxin

Hypothyroidism

Cocaine, heroin, alcohol

Cushing’s syndrome

Corticosteroids

Inherited myopathies

HMG-CoA reductase inhibitors, SSRIs, zidovudine

Acid maltase deficiency

Other

Muscular dystrophy

Sarcoidosis

Critical illness

Amyloidosis

Critical illness, sepsis, ventilator-associated injury

Paraneoplastic syndromes