The objective of this study is to evaluate the effect of intrathecal hydromorphone on the
duration of labor analgesia and the incidence of epidural-associated temperature increase in
laboring parturients. We hypothesize that intrathecal administration of longer-acting
hydromorphone will:
1. Prolong the duration and improve the quality of analgesia in labor, and
2. Decrease the incidence of epidural-associated temperature increase in labor.