Introduction:
Cesarean section (C/S) is usually performed under spinal with preservative free morphine for
pain relief, but the investigators have a severe shortage of this formulation of morphine.
Hydromorphone is a narcotic which acts peripherally and centrally to decrease pain. It has
been used in spinals for postoperative pain relief and in pain pumps for relief of chronic
pain. No randomized controlled studies have evaluated intrathecal (IT) hydromorphone for post
C/S pain.
Methods:
This is a randomized double-blind controlled trial utilizing the up-down sequential
allocation method1,2 to find the best dose of IT hydromorphone that provides pain relief
following C/S. Patients will be given a morphine PCA pump for additional pain relief. Our
first patient will receive 200 mcg of IT hydromorphone. Pain, nausea, and itching will be
evaluated at 4, 8, 12 and 24 hours following the C/S via numeric rating scales; vomiting and
morphine use per hour will be recorded. Success will be a median morphine usage of less than
or equal to 1mg/hour in the following 16 hours. If a success, the next patient will be given
10 mcg less IT hydromorphone; if a failure, she will receive 10 mcg more. The study will end
after 5 successes.
Objective:
The primary objective is to find the optimal dose of IT hydromorphone for pain relief
following C/S. The secondary objectives are to define the incidence and severity of
hydromorphone's side effects and determine the duration of analgesia.