Postoperative narcotic requirement after microscopic lumbar discectomy is not affected by intraoperative ketorolac or bupivacaine.

STUDY DESIGN: Prospective, randomized, double-blind study. OBJECTIVE: To assess the efficacy of ketorolac and bupivacaine in reducing postoperative pain after microsurgical lumbar discectomy. SUMMARY OF BACKGROUND DATA: Microsurgical lumbar discectomy often is performed as an ambulatory procedure. Pain, nausea, and urinary retention may delay discharge. It was hypothesized that intraoperative ketorolac or bupivacaine would reduce postoperative pain as measured by morphine demand. METHODS: After Institutional Review Board (IRB) approval and informed consent, 30 patients undergoing single-level microsurgical lumbar discectomy under general anesthesia randomly received either intravenous ketorolac, intramuscular bupivacaine, or placebo before wound closure. After surgery, all patients received intravenous, MSO4, patient-controlled analgesia. MSO4 demand was compared between groups at 30 minutes and at 1, 4, 8, 16, 20, and 24 hours after surgery by one-way ANOVA. Pre- and postoperative pain was assessed by using a standard scale and was correlated to postoperative MSO4 demand by Pearson correlation. Significance was assumed at P < 0.05. RESULTS: There were no group differences in age, gender, weight, disc level, preoperative pain, or preoperative use of pain medication. Neither ketorolac nor bupivacaine decreased pain or nausea scores, MSO4 demand, or time to void and ambulation. Preoperative pain was significantly correlated to postoperative narcotic demand (r = 0.46, P < 0.01). Preoperative narcotic or NSAID use was not correlated to either preoperative pain scores or postoperative MSO4 requirement. CONCLUSIONS: Neither ketorolac nor bupivacaine decreased the postoperative narcotic requirement in patients undergoing microsurgical lumbar discectomy. Postoperative narcotic requirements are increased in patients who are in severe pain before surgery, regardless of preoperative narcotic use.

The effect of lumbar epidural anesthesia on maternal middle cerebral artery blood flow in normal pregnancy: a prospective, randomized, double-blind comparison study.

OBJECTIVE: Lumbar epidural anesthesia is associated with a transient elevation in intracranial pressure in both animals and humans and decreased cerebral blood flow in animals. We sought to determine the effect of medium-onset and slow-onset local anesthetic lumbar epidural anesthesia on maternal cerebral blood flow in normal human pregnancy. STUDY DESIGN: In an Institutional Review Board-approved, double-blind study, 24 healthy, normotensive, nonlaboring, term gravida women undergoing elective cesarean section were prospectively placed into random groups to receive either 2% lidocaine with 8.4% sodium bicarbonate (1:10) or 0.5% bupivacaine lumbar epidural anesthesia. After prehydration with 20 mL/kg crystalloid and 15-degree left-wedged supine positioning with 15-degree head tilt, transcranial Doppler ultrasound (Nicolet Pioneer EME) and simultaneous electrocardiogram, automatic blood pressure (Dinamap), and end-tidal CO2 (SAR-Trans) monitoring were performed. Pulse, blood pressure, respiratory rate, end-tidal CO2, middle cerebral artery blood flow velocity, and pulsatility index were measured at (1) baseline (once supine positioning was assumed); (2) immediately after administration of 20 mL local anesthetic; and (3) every 5 minutes for 25 minutes. Timing of the attainment of a T4 dermatome anesthetic level was noted. Comparisons were made by t test, rank sum tests, chi2, and repeated measures analysis of variance. P <.05 was considered significant. RESULTS: Maternal heart rate, blood pressure, respiratory rate, and end-tidal CO2 were not significantly different within or between groups. No significant difference was found in baseline middle cerebral artery blood flow velocity or pulsatility index values between groups. Neither middle cerebral artery blood flow velocity nor pulsatility index changed significantly within or between groups up to 25 minutes after institution of epidural anesthesia. CONCLUSIONS: Maternal middle cerebral artery blood flow velocity, as measured by transcranial Doppler ultrasonography, is maintained in normotensive, nonlaboring term gravida women receiving either lidocaine or bupivacaine lumbar epidural anesthesia, which supports intact cerebrovascular autoregulation in normal pregnancy.