Patient-controlled epidural analgesia with low concentrations of anesthetics is effective in reducing labor pain. The aim of this study was to assess and compare two ultra-low dose regimens of ropivacaine and sufentanil (0.1% ropivacaine plus 0.5 μg.ml-1 sufentanil vs. 0.06% ropivacaine plus 0.5 μg.ml-1 sufentanil) on the intervals between boluses and the duration of labor.

PURPOSE: To evaluate in vitro lidocaine and racemic bupivacaine effects in neuromuscular transmission and in neuromuscular blockade produced by rocuronium. METHODS: Rats were distributed in 5 groups (n = 5) in agreement with the studied drugs: lidocaine, racemic bupivacaine, rocuronium, separately (Groups I, II, III); rocuronium in preparations exposed to local anesthetics (Groups IV, V). The concentrations used were: 20 µg/mL, 5 µg/mL and 4 µg/mL, for lidocaine, bupivacaine and rocuronium, respectively. It was evaluated: 1) amplitude of diaphragm muscle response to indirect stimulation, before and 60 minutes after separately addition of lidocaine, racemic bupivacaine and rocuronium and the association of local anesthetics - rocuronium; 2) membrane potentials (MP) and miniature end-plate potentials (MEPP). RESULTS: Lidocaine and bupivacaine separately didn't alter the amplitude of muscle response and MP. In preparations previously exposed to lidocaine and racemic bupivacaine, the rocuronium blockade was significantly larger (90.10 ± 9.15% and 100%, respectively), in relation to the produced by rocuronium separately (73.12 ± 9.89%). Lidocaine caused an increase in the frequency of MEPP, being followed by blockade; racemic bupivacaine produced decrease being followed by blockade. CONCLUSIONS: Local anesthetics potentiated the blockade caused by rocuronium. The alterations of MEPP identify presynaptic action.

PURPOSE: To compare the hemodynamic effects following a toxic dose of either agent after intravenous injection in swines, as might accidentally occur during regional anesthesia in humans. METHODS: Large White pigs were anesthetized with thiopental, tracheal intubation was performed and mechanical ventilation was instituted. Hemodynamic variables were recorded with invasive pressure monitoring and pulmonary artery catheterization. After a 30-minute resting period, the animals were randomly divided into two groups in a double-blinded fashion and received a bolus intravenous injection of 4 mg.kg-1 of either agent. Hemodynamic results were evaluated at rest and 1, 5, 10, 15, 20 and 30 minutes after intoxication. RESULTS: Hemodynamic repressions of acute intoxication with levobupivacaine were more important and more prolonged than those of ropivacaína. CONCLUSION: In pigs, levobupivacaine was shown to be more toxic than ropivacaine when the same large doses are injected intravenously.

PURPOSE: To determine the safety, pain intensity correlated with age and body mass index (BMI), epidural anesthesia with ropivacaine and clonidine in hemorrhoidectomy.METHODS: Eighty patients, both genders, 20-70 years old, ASA I or II, for hemorrhoidectomy were randomly divided into two groups: Control (n=38), epidural anesthesia with 14 mL of ropivacaine 0.75 % plus 0.0266 mL/kg of 0.9% saline solution; Experimental (n=42) epidural anesthesia with 14 mL of 0.75% ropivacaine plus 4.0 mcg/kg of clonidine. In preoperative and postoperative period were evaluated: systolic blood pressure (SBP), diastolic blood pressure (DBP ), heart rate (HR ), pulse oximetry (SpO2), electrocardiography (ECG), pain intensity (VAS ) in four, eight and, 12 hours and analgesic consumption.RESULTS: The VAS values differed between four, eight and 12 hours in the Experimental Group, where correlation of VAS 12h with age (p<0.05) occurred and not with BMI and more patients (p<0.05) did not receive analgesics. SBP, DBP, HR changed similarly in both groups at 15, 30 and 45 min. The ECG and SpO2 remained unchanged.CONCLUSIONS: Clonidine (4mcg/kg) in epidural anesthesia with ropivacaine 0.75% in hemorrhoidectomy showed safety and greater analgesia within four hours. The pain at 12 hours showed correlation with age and not with body mass index.

PURPOSE:To evaluate the efficacy and side-effects of fentanyl and sufentanil combined with hyperbaric spinal bupivacaine in elective cesarean section.METHODS:A prospective, randomized, double-blind study with 64 term parturients, distributed into 2 groups according to the opioid combined with hyperbaric bupivacaine 0.5% (10mg): GF - fentanyl (25µg) and GS - sufentanil (5.0µg). The latency and maximum sensory block level; degree and duration of motor block; duration and quality of analgesia; maternal-fetal repercussions were evaluated. This was an intention-to-treat analysis with a 5% significance level.RESULTS: The latency period, maximum sensory block level, motor block degree and perioperative analgesia were similar in both groups. Motor block and analgesia had a longer duration in the sufentanil group. Maternal adverse effects and neonatal repercussions were similar. The incidence of hypotension was higher in the fentanyl group. In both groups, there was a predominance of patients who were awake and either calm or sleepy.CONCLUSIONS:The addition of fentanyl and sufentanil to hyperbaric subarachnoid bupivacaine was shown to be effective for the performance of cesarean section, and safe for the mother and fetus. Analgesia was more prolonged with sufentanil.