Polymyositis & Dermatomyositis
Background
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Idiopathic inflammatory myopathies characterized by proximal skeletal muscle weakness & evidence of muscle inflammation
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Dermatomyositis but not polymyositis is associated with a variety of characteristic skin manifestations
Considerations
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Potential difficult airway (restricted temporomandubular joint & cervical spine mobility)
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Aspiration risk (esophageal dysfunction)
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Respiratory:
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Interstitial lung disease, pulmonary fibrosis
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Potential postoperative respiratory muscle failure & need for ventilation
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Cardiovascular:
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Myocardial fibrosis, myocarditis, conduction defects, arrhythmias
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Altered response to succinylcholine (theorectical hyperkalemia) & possible sensitivity to NdMRs (nondepolarizing muscle relaxants):
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Avoid succinylcholine, consider ↓ rocuronium dose
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Treatment: steroids, immunosuppressants, IVIG, monoclonal antibodies
Conflicts
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RSI for aspiration risk vs. difficult intubation
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RSI for aspiration risk vs. avoid succinylcholine
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RSI for aspiration risk vs. cardiac induction
Pregnancy Considerations
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Avoid succinylcholine if RSI for general anesthesia
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Caution with neuraxial if already compromised respiratory muscles