Polymyositis & Dermatomyositis 

 

 

Background 

 

  • Idiopathic inflammatory myopathies characterized by proximal skeletal muscle weakness & evidence of muscle inflammation 

  • Dermatomyositis but not polymyositis is associated with a variety of characteristic skin manifestations

 

 

Considerations

 

  • Potential difficult airway (restricted temporomandubular joint & cervical spine mobility) 

  • Aspiration risk (esophageal dysfunction) 

  • Respiratory:

    • Interstitial lung disease, pulmonary fibrosis  

    • Potential postoperative respiratory muscle failure & need for ventilation

  • Cardiovascular:

    • Myocardial fibrosis, myocarditis, conduction defects, arrhythmias 

  • Altered response to succinylcholine (theorectical hyperkalemia) & possible sensitivity to NdMRs (nondepolarizing muscle relaxants):

    • Avoid succinylcholine, consider ↓ rocuronium dose 

  • Treatment: steroids, immunosuppressants, IVIG, monoclonal antibodies

 

 

Conflicts

  • RSI for aspiration risk vs. difficult intubation

  • RSI for aspiration risk vs. avoid succinylcholine 

  • RSI for aspiration risk vs. cardiac induction

 

 

Pregnancy Considerations 

 

  • Avoid succinylcholine if RSI for general anesthesia

  • Caution with neuraxial if already compromised respiratory muscles