In Reply:-I appreciate the interest in our article expressed by Dr. Andrea Michalek-Sauberer. She raises four points regarding the diagnosis and management of malignant hyperthermia.
We agree that the use of “clinical grading scale for malignant hyperthermia”is useful for evaluating the probability of malignant hyperthermia. However, in our case report, we did not show the grading scale because the signs and symptoms indicated malignant hyperthermia undoubtedly. According to our hospital therapeutic protocol for malignant hyperthermia, dantrolene should be used initially at a dose of 1 mg/kg, body weight, and if the signs are not improved, additional doses of dantrolene, up to 7 mg/kg, are recommended. In this case, signs were improved with initially administered dantrolene at a dose of 100 mg. The highest concentration of creatinine phosphokinase was recorded at 78,672 U/l on the next day of the operation. The high concentration of creatinine phosphokinase strongly suggested the muscle destruction. Because we could not obtain the patient's consent to the muscle biopsy, no histologic nor pharmacologic information was available.
The patient, whose occupation was a manual laborer, had been healthy before the anesthesia. The muscle weakness occurred just after the episode of malignant hyperthermia. Because the recovery from muscle weakness was a matter of deep concern to the patient, we performed careful tests of his muscle strength repeatedly. Although there have been numerous reports regarding diagnosis or treatment of malignant hyperthermia, to our best knowledge, no precise description concerning muscle weakness as a post-episode of malignant hyperthermia have been made. In our case, it took 3 months to recover from this weakness. Our report may provide helpful information about the post-malignant hyperthermia muscle weakness.
Hiroshi Maeda, M.D.
Department of Anesthesiology; Wakayama Medical College; 7-bancho 27, Wakayama City; Wakayama, 640; Japan
(Accepted for publication December 10, 1997.)