Preoperative Management of Myasthenia Gravis

Preoperative Assessment

The American College of Physicians recommends a comprehensive respiratory assessment with measurements of negative inspiratory force (NIF) and vital capacity (VC) in patients with myasthenia gravis undergoing surgery 1
The American Academy of Neurology suggests checking acetylcholine receptor (AChR) and muscle-specific tyrosine kinase (MuSK) antibody levels in patients with myasthenia gravis 1, 2
The American College of Chest Physicians recommends considering a cardiac evaluation with electrocardiogram (ECG) and echocardiogram in patients with respiratory failure or elevated creatine phosphokinase (CPK) levels 1
The American Academy of Neurology suggests monitoring patients with myasthenia gravis for signs of myasthenic crisis, including respiratory failure, and considering plasma exchange or intravenous immunoglobulin (IVIG) therapy as needed 1

The American Academy of Neurology recommends continuing IVIG therapy at a dose of 2 g/kg divided over 5 days (0.4 g/kg/day) in patients with myasthenia gravis undergoing surgery 1, 3, 4
The American College of Rheumatology suggests considering high-dose corticosteroids, such as methylprednisolone 1-2 mg/kg/day IV or prednisone 1-1.5 mg/kg/day orally, in patients with myasthenia gravis 1

The American Academy of Neurology recommends using the "20/30/40" rule to identify patients with myasthenia gravis at risk for respiratory failure: vital capacity <20 mL/kg, maximum inspiratory pressure <30 cm H2O, or maximum expiratory pressure <40 cm H2O 1

The National Comprehensive Cancer Network recommends measuring serum antiacetylcholine receptor antibody levels in all patients suspected of having thymomas, even those without symptoms, to avoid respiratory failure during surgery 5
Patients with dysphagia, notable weight loss, or severe weakness should receive preoperative IVIG, as recommended by the Mayo Clinic 6

The Mayo Clinic recommends checking serum IgA levels before administering IVIG, as IgA deficiency may lead to severe anaphylaxis 6
Medical control of myasthenia gravis should be achieved before any surgical procedure, according to the National Comprehensive Cancer Network 5
The American Academy of Ophthalmology suggests continuing anticholinesterase medications (pyridostigmine) perioperatively unless contraindicated 7

Nature Reviews Neurology recommends monitoring closely for signs of myasthenic crisis postoperatively, including respiratory failure, and considering early tracheostomy in high-risk patients 8
Patients at risk for prolonged mechanical ventilation include those unable to lift arms from bed at 1 week after intubation and those with axonal subtype or unexcitable nerves on electrophysiology, as reported in Nature Reviews Neurology 8

Medical control of myasthenia gravis must be achieved before any surgical procedure, according to the National Comprehensive Cancer Network 9

The standard protocol for plasma exchange involves 5 sessions of plasma exchange (200-250 mL plasma/kg body weight or 1-L exchanges) performed every other day, 10-30 days before surgery, as recommended by Nature Reviews Neurology 10
The procedure should exchange twice the blood volume with fresh-frozen plasma or 5% albumin, as suggested by Circulation and Haematologica 11, 12

IVIG may be preferred over plasma exchange in most patients due to easier administration, wider availability, and fewer complications, according to Nature Reviews Neurology 10
The protocol for IVIG is 0.4 g/kg/day for 5 consecutive days (total 2 g/kg), as recommended by Nature Reviews Neurology 10