[Infusion speed as a factor to influence the analgesic level of spinal anesthesia--hypobaric solution of tetracaine].
In spinal anesthesia, as known, the injection speed of local anesthetic drug is a factor which influences the analgesic level. For study it, automatic infusion apparatus was available to control as 5 kinds of infusion speed (0.02-0.51 mL/s), and 78 patients were divided into 6 groups. The results of the painless level was discussed by T-test and distribution analysis (F-test). The mean of painless level in each group was found to be no significant difference as discussed by T-test. But the largest distribution was found in the group of 0.04 mL/s, and high analgesic level as rise up to T6 was occasionally found in groups of 0.04 mL/s & 0.02 mL/s. It means, the infusion speed is not an important factor, but extremely slow infusion is more dangerous than high speed infusion, which will take a risk of high level spinal anesthesia.