Measurement of the efficacy of 2% lipid in reversing bupivacaine- induced asystole in isolated rat hearts

BMC Anesthesiol. 2014 Jul 30;14:60. doi: 10.1186/1471-2253-14-60. eCollection 2014.

Abstract

Background: The reversal efficacy of 2% lipid emulsion in cardiac asystole induced by different concentrations of bupivacaine is poorly defined and needs to be determined.

Methods: Forty-two male Sprague-Dawley rats were randomly divided into seven groups: B40, B60, B80, B100, B120, B140 and B160, n = 6. The Langendorff isolated heart perfusion model was used, which consisted of a balanced perfusion with Krebs-Henseleit solution for 25 minutes and a continuous infusion of 100 μmol/L bupivacaine until asystole had been induced for 3 minutes. The hearts in the seven groups were perfused with Krebs-Henseleit solution containing a 2% lipid emulsion, and 40, 60, 80, 100, 120, 140 or 160 μmol/L bupivacaine, respectively. Cardiac recovery was defined as a spontaneous and regular rhythm with a rate-pressure product > 10% of the baseline value for more than 1 minute. Our primary outcome was the rate-pressure product 25 minutes after cardiac recovery. Other cardiac function parameters were also recorded.

Results: All groups demonstrated cardiac recovery. During the recovery phase, heart rate, rate-pressure product, the maximum left ventricular pressure rise and decline in heart rate in the B120-B160 groups was significantly lower than those in the B40-B80 groups (P < 0.05). The concentration of bupivacaine and the reversal effects of a 2% lipid emulsion showed a typical transoid S-shaped curve, R(2) = 0.9983, IC50 value was 102.5 μmol/L (95% CI: 92.44 - 113.6).

Conclusions: There is a concentration-response relationship between the concentrations of bupivacaine and the reversal effects of 2% lipid emulsion.

Keywords: Anaesthetics local-bupivacaine; Complications-cardiac arrest; Lipid emulsion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anesthetics, Local / administration & dosage
  • Anesthetics, Local / toxicity*
  • Animals
  • Bupivacaine / administration & dosage
  • Bupivacaine / toxicity*
  • Dose-Response Relationship, Drug
  • Fat Emulsions, Intravenous / administration & dosage*
  • Heart Arrest / chemically induced
  • Heart Arrest / therapy*
  • Inhibitory Concentration 50
  • Male
  • Rats
  • Rats, Sprague-Dawley

Substances

  • Anesthetics, Local
  • Fat Emulsions, Intravenous
  • Bupivacaine