BACKGROUND: Atracurium, a nondepolarizing muscle relaxant, is eliminated by Hofmann elimination and not affected by pseudocholinesterase(pChe). Many reports show fall in pChe activity during pregnancy and our measurement failed to prove it. However, the authors found previously the infusion rate of mivacurium, which is metabolized by pChe, to achieve surgical relaxation is decreased. So, we compared the difference in the infusion rate of atracurium between full-term pregnant and nonpregnant women. METHODS: Muscle relaxation of full-term pregnant women(C group, n=10) and nonpregnant women (Non-C group, n=10) was maintained by continuous infusion of atracurium to keep 1st response of TOF at 5 1%. After discontinuance of infusion, recovery index was measured without reversals using the accelerograph. RESULTS: There was no significant difference in infusion rate of atracurium to maintain 1st twitch response of TOF at 5 1% and recovery index between two groups. There was little correlation between the total infusion time and infusion rate, or between the total infusion time and recovery index. CONCLUSION: The atracurium infusion rate in parturients to maintain muscle relaxation was not different from that in non-parturients. For Cesarean section, the usual infusion rate of atracurium is recommended to achieve the adequate surgical relaxation.
Atracurium* ; Cesarean Section* ; Female ; Humans ; Muscle Relaxation ; Obstetrics ; Pregnancy ; Relaxation

BACKGROUND: With different injection levels, the dose-requirements of epidural opioids association with lipid solubility are controversial. The purpose of this study was to compare the effect of patient controlled lumbar(L group) and thoracic(T group) epidural morphine on dose-requirements, analgesia and side effects after thoracotomy. METHODS: Twenty patients were randomly assigned into one of two groups. Before the induction of general anesthesia, the epidural taps with 17G with Tuohy needle were done on the 6th or 7th thoracic and 2nd or 3rd lumbar intervertebral levels, respectively. The epidural catheter tips were placed 3~4 cm above the needle tips in either groups . Morphine 3 mg in 3 ml normal saline was administered via the epidural catheter in all the patients immediately at the end of surgical manipulation. PCA/basal infusion dose and lockout interval was 0.02 mg/once, 0.08 mg/hr and 5min respectively. After the initial dose dose-requirements were checked at 4, 8, 24 and 48hour and pain was assessed on visual analogue scale at 1, 4, 8, 24 and 48hour. Side effects were observed. RESULTS: There were no significant difference between groups in the dose-requirements of morphine, their analgesia and side effects. CONCLUSIONS: Lumbar epidural morphine provides postoperative analgesia after thoracotomy that is clinically indistinguishable from that provided by thoracic epidural morphine with respect to dosage, quality of analgesia and side effect.
Analgesia ; Analgesia, Epidural* ; Analgesia, Patient-Controlled ; Analgesics ; Analgesics, Opioid ; Anesthesia, General ; Catheters ; Humans ; Morphine* ; Needles ; Solubility ; Thoracotomy