The Analgesic Effect of Single Dose of Intrathecal Magnesium Sulfate / 대한마취과학회지

BACKGROUND: Intrathecal (IT) magnesium has antinociceptive effects on animals and has been reported to prolong spinal opioid analgesia in humans. This study examined the effect of IT magnesium on spinal anesthesia and postoperative epidural analgesia. METHODS: Sixty patients undergoing total knee replacement were enrolled in this study. Before the IT injection of 0.5% isobaric tetracaine (10 mg), group C and group M received 0.9% saline or 50% magnesium sulfate 0.1 ml, respectively. The epidural solution for postoperative analgesia contained 0.2% ropivacaine (100 ml) only in group M, and 0.2% ropivacaine plus morphine (50microgram/ml) in group C. The verbal rating scale (VRS) scores for pain, sensory block level, intensity of motor block and side effects were recorded at 5, 60, and 120 minutes after the IT injection and at 1, 12 and 36 hours after surgery in the post-anesthesia care unit (PACU). RESULTS: The VRS score at 120 minutes after the IT injection were lower in group M than in group C (P< 0.05). There were no differences in the VRS scores and the use of supplemental analgesics at the postoperative period. The incidence of PONV, pruritus and urinary retention was significantly lower in group M than in group C at 12 and 36 hours after surgery. CONCLUSIONS: IT magnesium can be used as a local anesthetic adjuvant to strengthen the analgesic effect of spinal local anesthesia and to intensify the analgesic effect of epidural local anesthesia for postoperative pain control to the extent of 5 mg epidural morphine.

The Effect of Doxazosin Premedication on Urinary Retention after Epidural Morphine / 대한마취과학회지

BACKGROUND: Urinary retention is the most common and distressing complication in the postoperative period after an epidural morphine administration. In this prospective placebo-controlled study, the efficacy of doxazosin on preventing urinary retention after epidural morphine was investigated. METHODS: A total of 75 males who underwent elective arthroscopic knee surgery were randomized into three groups. Patients in group I received a placebo orally before surgery. Group II patients received 4 mg of doxazosin, and group III patients received 8 mg of doxazosin. In all patients, 2 mg of epidural morphine in 6 ml normal saline was administrated by the epidural route in the L3-4 interspace. General anesthesia was induced in all patients. The volumes of the first two postoperative urine voidings, the time intervals between the end of surgery and the first micturition and the need for bladder catheterization were recorded. RESULTS: There were statistically no significant differences among the groups in the first two postoperative voidings (Group I 449 ml/445 ml, Group II 343 ml/388 ml, Group III 376 ml/380 ml). No significant differences were noted among the three groups in the mean time between the end of the surgery and the first micturition (Group I 467 minutes, Group II 440 minutes, Group III 366 minutes). Also, with urinary catheterization, there were no differences among the groups (G I6/25, G II 5/25, G III 7/25). CONCLUSIONS: Prophylactic use of doxazosin does not prevent postoperative urinary retention after epidural morphine.

The Influence of Epidural Fentanyl and Meperidine injected during Cesarean Section on the Efficacy of Epidural Morphine / 대한마취과학회지

Drug interactions between intraoperative epidural fentanyl and meperidine (pethidine) added to epidural local anesthetic agent and postoperative epidural morphine for potentiation of the quality of intraoperative and postoperative analgesia during Cesarean section are controversial. The purpose of this study was to determine the influence of epidural fentanyl or meperidine on the efficacy of epidural local anesthetics and morphine during and after Cesarean section, respectively. Epidural anesthesia was established using a local anesthetic mixture of 2% lidocaine 10 ml and 0.5% bupivacaine 20 ml with epinephrine 1: 200,000 by fractionated dose administered via epidural catheter to anesthetize the patient up to T-4 sensory dermatome in 107 patients scheduled for elective Cesarean section. After delivery, 107 patients were received one of the following study drugs epidurally in a randomized, double-blind manner: saline 10 ml in saline group (n=50), fentanyl 100 ug/10 ml in fentanyl group (n=33), and meperidine 25 mg/10 ml in meperidine group (n=24). All patients were received 3.5 mg of morphine diluted with saline 6 ml epidurally just after peritoneal closure. Additional administration of the epidural fentanyl or meperidine didn't influence analgesic effect of the local anesthetics injected epidurally. In fentanyl group, postoperative pain, nausea, and sedation were more severe than saline group. In meperidine group, the incidences of intraoperative nausea and vomiting were highest among the groups, but the degree of postoperative pain, nausea, itching, and sedation were not significant. In conclusion, intraoperative injection of epidural fentanyl or meperidine were ineffective for the efficacy of epidural local anesthetics and morphine.