Does your standard rapid seuence intubation (RSI) technique need to be modified when intubating patients with myasthenia gravis (MG)?

Maybe. Depends on your technique.

• MG patients are supersensitive to nondepolarizing muscle relaxants. Avoid if possible otherwise use smaller amounts, 0.1 - 0.05 of the normal dose, as this will be enough to block the fewer number of acetylcholine receptors. If used in usual doses, prolonged weakness may ensue.
  
• MG patients have a resistance to succinylcholine. A higher dose in the range of 1.5 - 2 mg/kg should be used. Preoperative administration of pyridostigmine or other anticholinesterase inhibitors used to treat MG, however, may prolong the action of succinylcholine.

Source

Barash, P. MD. , Clinical Anesthesia. Lippincott Williams and Wilkins. 2001.

Dunn, P. MD., Clinical Anesthesia Procedures of the Massachusetts General Hospital. 7th ed.

Bowman-Howard, M. MD. Anesthesia Review. Lippincott Williams and Wilkins. 2007.