title: Measurement of the efficacy of 2% lipid in reversing bupivacaine- induced asystole in isolated rat hearts.
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.
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, 2 Fuxue Road, 325000 Zhejiang, China.
authors.forename: Hongfei
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, The Ohio State University Medical Center, Ohio, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, 2 Fuxue Road, 325000 Zhejiang, China.
authors.forename: Binbin
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, 2 Fuxue Road, 325000 Zhejiang, China.
authors.forename: Xiawei
authors.initials: X
authors.lastname: Hu
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, 2 Fuxue Road, 325000 Zhejiang, China.
authors.forename: Shihao
authors.initials: S
authors.lastname: Xu
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, 2 Fuxue Road, 325000 Zhejiang, China.
authors.forename: Limei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, The Ohio State University Medical Center, Ohio, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Papadimos
authors.affiliation: Department of Pathophysiology, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Wantie
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, 2 Fuxue Road, 325000 Zhejiang, China.
authors.forename: Quanguang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, 2 Fuxue Road, 325000 Zhejiang, China.
authors.forename: Xuzhong
authors.initials: X
authors.lastname: Xu
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage / Q000633:toxicity*; D000818:Animals; D002045:Bupivacaine / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005217:Fat Emulsions, Intravenous / Q000008:administration & dosage*; D006323:Heart Arrest / Q000139:chemically induced / Q000628:therapy*; D020128:Inhibitory Concentration 50; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000779:Anesthetics, Local; D005217:Fat Emulsions, Intravenous; D002045:Bupivacaine
keywords: Anaesthetics local-bupivacaine; Complications-cardiac arrest; Lipid emulsion
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