[Effect of age on dose requirement for lumbar epidural anesthesia]

In 161 patients, aged 19-75 yr and subjected to epidural anesthesia for extracorporeal shock wave lithotripsy, the relationships between the spread of lumbar epidural analgesia with 10 ml of 2% mepivacaine and age, height, weight, weight/height ratio, and body mass index were studied. The highest correlation was found between the age and the spread (r = 0.67, P < 0.001). The next higher correlation was found between the height and the spread (r = -0.32, P < 0.001). The lowest but a statistically significant correlation was found between the body mass index and the spread (r = 0.16, P < 0.05). A strong inverse linear relationship was found between the age and the epidural dose requirement (r = -0.59, P < 0.001).