Abstract
The anesthetic management of patients undergoing surgery of lower extremity is fre-quently done under hyperbaric spinal anesthesia with dibucaine, and general anesthesia is used for operations of longer duration, such as total hip replacement. In hospitals with a rather small staff in the department of orthopedic surgery and no anesthesiologists avail-able like ours, the anesthetic management has to be done by the doctors of other depart-ments or anesthesiologists of other hospitals. So we took advantages of hypobaric spinal anesthesia with tetracaine. The advantages of this technic are: 1) Good analgesia and muscle relaxation can be achieved without respiratory or myocardial depression. 2) It is easy to place patients unaffected side up during the spinal puncture. 3) Relatively longer duration of anesthesia can be obtained.
The solution used for hypobaric spinal anesthesia is 20 mg tetracaine diluted in 37°C distilled water 10 ml with 0.1% epinephrine 0.1 ml. For premeditation scopolamine 0.5 mg and Atarax P(R) 25 mg are administered. The position for lumbar puncture is lateral decu-bitus position with unaffected side up and with slight head down. We compared the blood loss and operative duration of total hip replacement under general and hypobaric spinal anesthesia. Total hip replacements were performed twenty seven times in 28 patients from 1976 to 1983. The number of operations under general anesthesia were 15 in 14 patients; hypobaric spinal anesthesia; 12 in 10 patients. Average blood loss was 1172±498 g for general anesthesia and 547±182 g for spinal anesthesia. Average time of operation was 154±25 min. for general and 120+34 min. for spinal anes-thesia. Average blood loss per hour was 496±233 g for general and 251±80 g for spinal anesthesia. Blood loss was less and duration of operations was statistically shorter under spinal anesthesia compared with general anesthesia.
The disadvantages of this technic incude hypotension which is controlled by fluid infu-sion or intravenous injection of Carnaculin(R), consciousness during the operation, the possible complication of spinal anesthesia itself and discomfort produced by prolonged immobility. But they can be minimized by careful management. Thus we recommend usefulness of this technic which can be performed safely and steadily.
