A comparison of inhibiting the toxic effects of bupivacaine with using different lipid emulsion in rats

SUMMARY A comparison of inhibiting the toxic effects of bupivacaine with using different lipid emulsion in rats In anesthetized rats, different lipid emulsions preventiveeffects on bupivacaine induced toxictywere investigated in randomized,controlled,experimental study. Twenty-fiveadult femaleWistar-Albino rats were used. Preliminary studieswere performed to check the lethal dose and observe the experimental progress. Seizureswere observed in all rats following the administration of calculated bupivacaine dose during thepreliminary study. After preliminary studies, lipid emulsion administration time was decidedtothe onsetof seizures.The ratswererandomizedinto 3 groups;Group 1: Intralipid® % 20 (n:8), Group 2: ClinOleic® % 20 (n:9) and Group 3: SMOFlipid® % 20 (n:8) The rats were anesthetized with ether and monitorized for SpO2 and heart rate.Venouscannulationwas achievedby a 22-gauge cannula andfixed. After injection of 5 mg/kg Bupivacaine dose to each group,seizure development was expected.Rats which had seizure, considered that toxicity occured.Lipid emulsion at 3 ml/kg dose was administrated to each group via venous cannula. Ratswere observed forgeneral condition andmonitorizedfor 3 minutes. Seizure duration, timeofseizureoutcomeand / orexitusdevelopment timewere recorded. Seizure activity terminated and the surviving ratswere accepted tobe prevented from the toxicity. At dead rats we considerthat the toxicity couldn't be prevented. In statistical analysis Cox regression and Chi-square tests were used, p < 0.05 was considered significant. Initial values were not significantly differentbetween groups. Factors (dose-group-weight) that effect on seizure durationand conditions of life were not significantly differentbetween groups.Thestatus-group relations were not significantly differentbetween groups. At the end,bupivacainetoxicityin ratscan be preventedwith lipid emulsions and there wasn't a difference between the ü effects of used lipid emulsions. Key words: Bupivacaine, toxicity, lipid, rat