Motor and Sensory Disability Has a Strong Relationship to Induction Dose of Thiopental in Patients with the Hypertropic Variety of Charcot-Marie-Tooth Syndrome

Abstract

In a prospective study, we determined the anesthetic induction dose of thiopental and the clinical variables influencing the appropriate induction dose of thiopental in 20 patients with the hypertrophic variety of Charcot-Marie-Tooth syndrome (CMT). As controls we chose 50 patients without CMT. Motor disturbance was evaluated in terms of muscle weakness of the distal lower and upper extremities. We examined sensory disturbance by evaluating loss of sensation in the index finger and great toe. The preinduction cardiac output was measured by echocardiography. Anesthesia was induced with repeated injections of 50 mg thiopental. The minimum induction dose of thiopental (MID) was confirmed when the eyelash reflex ceased. We maintained anesthesia with enflurane and nitrous oxide. The 95% confidence interval of the MID in patients used as the controls was 2.5-4.9 mg/kg. The MID in 11 patients with CMT was less than 2.5 mg/kg. MIDs in the patients with CMT were significantly smaller than those of the control patients (P < 0.0001). Also we found a strong relationship between the MID and the severity of both motor and sensory disturbances (P = 0.003 and 0.002, respectively). There was no relationship between the MID and other clinical variables, such as age, gender, inherited type, body weight, and preinduction cardiac output. Because delay in the recovery from anesthesia can be caused by an inappropriate dose of thiopental in CMT patients in whom motor and sensory function is seriously impaired, the dose of thiopental probably should be reduced and based on the individual patient's response.