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We administered a calcium channel blocker, nicardipine 0.01 mg.kg-1 i. v. bolus or 5 micrograms.kg-1.min-1 i. v. infusion before induction with thiamylal or modified NLA (thiamylal, droperidol and butorphanol) to prevent hypertension at intratracheal intubation, and measured blood pressure and heart rate before and after intubation. Blood pressure of all experimental groups was significantly reduced in comparison with the control group right after intubated. Nicardipine is effective to prevent hypertension at intubation.

We used the laser flowmeter to measure and compare the effect of nitroglycerin (TNG), trimetaphan (TMP) and prostaglandin E1 (PGE1) on the blood flow of operating field during hypotension induced by each drug. The study was done in 33 patients (TNG:13, TMP:13 and PGE1:7) anesthetized with modified NLA who underwent radical mastectomy. We put the probe of the laser flowmeter on the skin of the opposite breast to the operating field and measured the skin blood flow change. Measurements were made before and during hypotension induced by each drug. TMP-induced hypotension decreased blood flow significantly (P less than 0.05), but TNG and PGE1 had no significant effect. Intraoperative blood losses of TNG and PGE1 group were not significantly larger than that of TMP group. From this study we conclude that TNG, TMP and PGE1 can dry the operating field and decrease intraoperative blood loss similarly. Therefore we should choose the drugs to induce hypotension considering the effect of the drug on blood flow of the important organs and each patient's complications.

General anaesthesia with Althesin was administered on two occasions to a patient who was identified as susceptible to malignant hyperthermia, in whom there was identified familial subclinical myopathy and once in another patient suffering from arthrogryposis multiplex congenita with a history of fever associated with two previous anaesthetics. In the first patient halothane was administered by accident in association with the Althesin, but no hyperpyrexia occurred. In the second instance nitrous oxide-oxygen and halothane were associated purposely with Althesin. In none of these cases was there any rise in temperature, muscle rigor or elevation of the serum CPK level. This experience corroborates the experimental evidence of Hall, et al.10 and Harrison, who reported that Althesin prevented the onset of hyperthermia, and the clinical reports of Page and Judelman. Althesin can be assumed to be an effective anaesthetic for malignant hyperthermia susceptible patients.