Abstract
Segmental dose requirement of 2% mepivacaine in thoracic epidural anesthesia was examined. Two groups of patients scheduled for upper abdominal surgery were studied. Patients in group I (n=35) were over seventy years old and patients in group II (n=34) were younger than fifty years old. A Tuohy needle was inserted into the epidural space at one of the seventh to ninth thoracic interspace. Patients in group I and group II received 3ml and 6ml of 2% mepivacaine, respectively. Fifteen minutes after injection of mepivacaine, the extension of analgesia was evaluated by the pin-prick technique. As there was a significant difference in height between the two groups, segmental dose requirement per patients' height (ml/seg/M) as well as segmental dose requirement (ml/seg), was calculated. The doses in group I and II were 0.57 and 1.01ml/seg, respectively. The doses per patients' height in group I and group II were 0.37 and 0.61ml/seg/M, respectively. Both ml/seg and ml/seg/M were significantly smaller in group I than group II (p<0.01). Present results indicate that less anesthetic solution is needed in elderly patients for thoracic epidural anesthesia.
