Weakness in the ICU: GBS & MG

• Myasthenic crisis: intubate when FVC <15 mL/kg or NIF >−20; treat with IVIG or PLEX; on the ventilator hold pyridostigmine; steer clear of crisis drugs (aminoglycosides, Mg, β-blockers).
• GBS: PLEX ×5 and IVIG 2 g/kg work equally; track FVC/NIF (20/30/40 rule) — autonomic swings kill.
• Botulism: early antitoxin plus supportive ventilation; descending paralysis with pupils.
• ICU-acquired weakness: cut steroids/NMB/sedation; mobilize early.
• Steroids are NOT recommended in GBS (2023 EAN/PNS).

Management of Neuromuscular Respiratory Failure

• Identify patients at risk for neuromuscular respiratory failure (Table 59.2)
• Close respiratory monitoring: spirometry (NIF, FVC) q6–12 hr · oxygen saturation · can patient lift head off bed, count to 20? · monitor cough and secretion clearance adequacy · ABG if respiratory symptoms or hypoventilation concern · CXR if desaturation or fever
• Aggressive pulmonary toilet: incentive spirometry (q1h) · mobilization against atelectasis · suctioning prn · glycopyrrolate for copious thin secretions · minimize sedatives · swallowing evaluation for dysphagia · aspiration prevention with post-pyloric feeding and/or motility agents
• Impending NMRF signs: FVC <15 mL/kg or 30% drop · NIF below −30 cm H₂O · cannot clear secretions · desaturation · hypercapnia
• Endotracheal intubation: avoid succinylcholine/NMBs · mechanical ventilation (settings per degree of weakness) · follow NIF/FVC daily on vent · wean as weakness improves with daily SBT once FVC >7 mL/kg · delay tracheostomy 1–2 weeks
• Treat the underlying disorder where possible: plasmapheresis or IVIG for GBS or MG · EMG/NCS for diagnosis if required · corticosteroids for inflammatory myopathy, CIDP, or MG (low-dose) · antibiotics for pneumonia/infections