59 ASA I and II children undergoing orthopedic surgery were randomized to either receive: 1) intrathecal bupivacaine and intravenous saline, 2) intrathecal bupivacaine in combination with clonidine and intravenous saline, or 3) bupivacaine and intravenous clonidine in saline, in order to compare their effects on postoperative analgesia/sedation and intraoperative propofol requirements. Following assessments over a 12 hour period, the results indicated that regardless of intrathecal or intravenous administration, clonidine was effective in extending the amount of the time until the first dose of propofol was needed following surgery, and in reducing the total amount of propofol required. However, only intrathecal bupivacaine and clonidine prolonged the sensory and motor blocks in the patients.