Comparison of Intrathecal Fentanyl Infusion with Intrathecal Morphine Infusion or Bolus for Postoperative Pain Relief After Hip Arthroplasty

Abstract

The purpose of this study was to compare an intrathecal fentanyl infusion with intrathecal morphine infusion or bolus for postoperative pain relief after hip arthroplasty. Sixty patients scheduled to undergo hip joint replacement were studied. A 28-gauge (n = 12) or a 22-gauge (n = 48) spinal catheter was introduced through the L3-4 interspace, 3-4 cm into the subarachnoid space. Spinal anesthesia was induced with 2 mL of plain 0.5% bupivacaine; additional bupivacaine was given in 0.5-mL increments, as required. Patients were given in a random and double-blind fashion either 0.5 mL of saline as a single bolus, followed by an infusion of 120 micrograms of fentanyl in 24 h (Group I, n = 20), 0.5 mL of saline, followed by an infusion of 200 micrograms of morphine in 24 h (Group II, n = 20), or 200 micrograms of morphine as a single bolus, followed by an infusion of 3 mL of saline in 24 h (Group III, n = 20) through the intrathecal catheter. In Group I, supplementary intramuscular (IM) opioid was required more often (46 doses) than in Group II (18 doses) in 24 h (P < 0.01). The number of patients given IM administered opioid was larger in Group I (18 patients) than in Group II (8 patients) (P < 0.01). The IM opioid was requested sooner in Group I (18 patients, mean 480 min) after the intrathecal injection than in Group III (13 patients, mean 786 min) (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)