Hemodynamic effects of local anesthetics intoxication. Experimental study in swine with levobupivacaine and bupivacaine

Purpose: To compare the hemodynamic repercussions following a toxic dose of levobupivacaine and bupivacaine intravascularly injected in swines. 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 (Swan-Ganz catheter). After a 30-minute resting period, the animals were randomly divided into two groups in a double-blinded fashion and received a bolus injection of 4 mg/kg of either agent for intoxication. Hemodynamic results were then evaluated at 1, 5, 10, 15, 20 and 30 minutes. Results: Levobupivacaine had greater hemodynamic repercussions than racemic bupivacaine. These results disagree with those found when the levorotatory isomer of bupivacaine was used in humans, but are in agreement with recently reported findings in animals. Conclusion: Levobupivacaine was shown to be more toxic in pigs than racemic bupivacaine when large doses are injected intravenously.231556

Haemodynamic effects of intoxication with bupivacaine and enantiomeric excess mixture. experimental study in swine

BACKGROUND. Racemic bupivacaine has been the local anaesthetic of choice in regional blocks due to quality and duration of anesthesia. However Its cardiovascular toxicity has been a source of concern and research has been made for lesser Impact drugs. One choice is its levogyre isomer, levobuoivacaine, apparently less cardiotoxic due a lower affinity to the heart sodium channels. In Brazil, a drug containing 7596 of levogyre isomer and 25961 of dextrogyre isomer, called enantiomeric excess mixture, is available. This study Intends to evaluate haemodynamic effects of the Intravascular injection of a toxic dose of both agents In swine. METHODS. Large White pigs were anaesthetized with thiopental, Intubated and placed on mechanical ventilation. Haemodynamic monitorin Was performed with an Invasive blood pressure and Swan-Ganz catheter on a pulmonary artery. Mer a 30 minute rest period, animals were randomly divided In two groups and the intoxication was performed on a double-blind method with 4 mg.kg of one of the drugs. Haemodynamic parameters were then evaluated at 1, 5, 10, 15, 20 and 30 minutes. RESULTS. The enantiomeric excess mixture caused greater haemodynamic effects than the racemic buoivacaie, These results diverge from those found in humans with levogyre isomer but are similar to recent results reported In animals. Care should be taken when extrapolating data obtained in swine to humans and further research is necessary. CONCLUSION. When high doses are injected in swine, the enantiomeric excess mixture was more toxic than the racemic bupivacaine.53650250