Muscle Relaxant Effect of Isoflurane in Patients with Myasthenia Gravis

Abstract

Nineteen patients with myasthenia gravis were anesthetized with isoflurane (N₂O-O₂ -Isoflurane, GUI) or ènflurane (N₂O-O₂-Ènflurane, GOÈ), prior to undergo transsternal thymectomy.
The larynx was very easily visualized following slow induction with either inhaled anesthetic for ten minutes.
The patients anesthetized with GOI demonstrated stable hemodynamics during the operation, and adequate muscle relaxation was obtained for operation as shown by the depression in T₁ and TR.
Using a scoring system which predicts the postoperative need for mechanical ventilation, we found that Isoflurane had no adverse effects on postoperative respiratory function.
As the blood/gas coefficient of isoflurane is smaller than that of ènflurane, induction and recovery from GOI may be accomplished more quickly than that with GOÈ.
In conclusion, isoflurane may be a useful anesthetic agent for myasthenic patients.