[Effect of intra and postoperative magnesium sulphate infusion on postoperative pain]. / Effet de l'administration intraveineuse per et post-opératoire du sulfate de magnésium sur la douleur post-opératoire.

AIM: Evaluate the effect of intra and postoperative magnesium sulphate infusion on postoperative pain in abdominal surgery. METHODS: Prospective double-blind randomized controlled study. Forty eight patients were randomly allocated to receive in the induction of anaesthesia, intraoperatively and six hours postoperatively either magnesium sulphate M Group (bolus 50 mg/kg and 0.5 g/h) or placebo (P Group). Patients were given a dose of morphine (0.1 mg/kg) IV, 45 min before the end of surgery. Sedation, pain scores, cumulative morphine consumption and adverse effects were recorded up to 24 hours postoperatively. RESULTS: The duration of anaesthesia was similar in both groups. The time of the first demand of morphine was significantly longer in M Group then in P Group, respectively (18+/-5 min vs 7+/-1 min, p=0.03). Morphine consumption was significantly higher in control group than M group on the first postoperative day (52+/-4 mg vs 30+/-3 mg, p=0.0002). Pain scores were significantly lower in M group than in P group. Serum magnesium concentration was significantly higher in the M group. The frequency of side effects was similar in the two groups. CONCLUSION: The results of the study support magnesium sulphate as useful adjuvant for postoperative analgesia in abdominal surgery.

Spinal anesthesia for endoscopic urological surgery--low dose vs. varying doses of hyperbaric bupivacaine.

BACKGROUND AND OBJECTIVE: The aim of this study is to compare the efficiency of low dose vs. varying doses of hyperbaric bupivacaine in spinal anesthesia for endoscopic urological procedures. METHODS: Sixty consecutive patients were studied in a randomized prospective manner. They received either of 5 (Gr I), 7.5 (Gr II) or 10 mg (Gr III) of hyperbaric bupivacaine 0.5% combined with 25 microg of fentanyl, through a 25-gauge W hitacre spinal needle placed in the L3-L4 interspace. Characteristics of sensory and motor block, dose of ephedrine required, secondary effects, the patients, and the surgeons satisfaction, were noted. RESULTS: The maximum number of blocked segments was 14 +/- 1 (Gr I), 15 +/- 2 (Gr II) and 16 +/- 2 (Gr III). Time to T12 regression was significantly shorter for Gr I (53 +/- 13 min) than for Gr II (69 +/- 20 min) or Gr III (94 +/- 14 min). Bromage 3 block was not found in Gr I compared to 4 patients in Gr II and 15 patients in Gr III. The duration of motor block was shorter in Gr 1(51 +/- 18 min) than in Gr II (86 +/- 19 min) and in Gr III (138 +/- 21 min). Ephedrine was used for 16 patients in Gr III (9.8 +/- 12.2 mg), 5 patients in Gr II (3.7 +/- 7.8 mg) and 2 patients in Gr I (0.5 +/- 1.5 mg). The difference is statistically significant between Gr III and the other groups. CONCLUSIONS: These results suggest that the use of a low dose of bupivacaine (5 mg) added to fentanyl (25 microg) for endoscopic urological surgery, resulted in short-acting sensory block, without motor block and a lower incidence of cardiovascular side effects, as compared to either of 7.5 or 10 mg bupivacaine with 25 microg fentanyl.