Spread of subarachnoid hyperbaric amethocaine in adolescents

We have compared the spread of subarachnoid hyperbaric amethocaine in adolescents with that in adults. Amethocaine 8 mg in 2 ml of 10% glucose was injected through a 25-gauge spinal needle inserted at the L3-4 interspace in 21 adolescents aged 12-16 yr and in 111 adults aged 17-82 yr. Although we found no differences in height, weight or body mass index between the adolescents and adults, maximum spread of analgesia was significantly higher in the adolescents (median T3 (range T4-C5) than in the adults (T4 (T9-C7)). We conclude that subarachnoid injection of hyperbaric amethocaine produces an unexpectedly higher level of analgesia in adolescents than in adults.