1 / 21

Lipid Emulsion Infusion Rescues Dogs From Bupivacaine-Induced Cardiac Toxicity

Lipid Emulsion Infusion Rescues Dogs From Bupivacaine-Induced Cardiac Toxicity Weinberg et. al. Regional Anesthesia and Pain Medicine Vol 28, No 3 (May-June), 2003: pp 198-202 Overview Purpose:

arleen
Download Presentation

Lipid Emulsion Infusion Rescues Dogs From Bupivacaine-Induced Cardiac Toxicity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Lipid Emulsion Infusion Rescues Dogs From Bupivacaine-Induced Cardiac Toxicity Weinberg et. al. Regional Anesthesia and Pain Medicine Vol 28, No 3 (May-June), 2003: pp 198-202

  2. Overview • Purpose: • author previously demonstrated encouraging results in resuscitation of severe bupivacaine cardiac toxicity in rats treated w/ IV lipid emulsion infusion. • Authors wanted to test hypothesis that Bupivacaine-induced cardiac toxicity in dogs (larger non-rodent mammals) could also be treated w/ lipid emulsion infusion.

  3. Overview… • Methodology: • Bupivacaine 10 mg/kg IV over 10 sec. • Resuscitation • internal cardiac massage x 10 min • Either saline or 20% lipid infusion @ 4 mL/kg bolus then 0.5 mL/kg/min x 10 min • EKG, MAP, pHm, pmO2 monitored

  4. Overview… • Significant findings: • Survival after 10 min unsuccessful cardiac massage • 100% for lipid treated dogs • 0% for saline treated dogs • Hemodynamics (PmO2, pHm) • Improved during resuscitation w/ lipids vs. saline

  5. Overview… • Conclusion: • Infusing lipid emulsions during resuscitation from bupivacaine-induced cardiac toxicity substantially improved • Hemodynamics, pmO2, and pHm • Substantially increased survival in dogs.

  6. Authorship • Guy Weinberg et al: • Department of Anesthesiology, University of Illinois at Chicago College of Medicine • Supported by Department of Anesthesiology at same school.

  7. Audience • Anesthesiologists and all MDs

  8. Impact • Increasing use of regional techniques • Bupivacaine-induced cardiac toxicity rare, but quite fatal • Could prove to be huge breakthrough

  9. Introduction • Author clearly underlines significance of problem with opening statement: • “Bupivacaine overdose can lead to fatal cardiac toxicity in the form of severe arrhythmias and contractile dysfunction.” • Situates his own research by discussing his previous research on rats.

  10. Introduction… • Hypothesis clearly stated: • “We hypothesized that lipid infusion following bupivacaine treatment would improve recovery of cardiac function, hemodynamics, and myocaridal metabolism compared with saline-treated controls”.

  11. Methodology • Approved by Institutional Animal Care Committee • 12 male non-purpose bread hounds (22-26 kg) • ? Randomly assigned to tmt vs. non-tmt arm • Non-blinded

  12. Methodology… • Instruments described: • Very detailed description of tissue probe • Anesthetic technique • 5 mg/kg propofol • Intubated ventilated w/ 1.5% Isoflurane + 30% O2 • Details probe insertion, and surgical preparation of the animals etc.

  13. Methodology… • Details of bupivacaine overdose and subsequent resuscitation: • 10 mg/kg bupivacaine over 10 sec • Time of circulatory arrest noted (HR<10, MAP<30) • d/c Isoflurane and started 100% O2 • Internal cardiac massage initiated x 10min • 4 mL/kg bolus (over 2 min) either saline or lipid emulsion • followed by continuous infusion 0.5 mL/kg/min x 10 min

  14. Methodology… • If NSR returned, internal cardiac massage continued until: • MAP>30mm Hg • 30 minute recovery measures recorded • All dogs sacrificed at the end.

  15. Methodology… • Statistics: • Statistical analysis tools used by author clearly identified in “statistics” subsection of Methods section.

  16. Results… • Major findings presented clearly in results section: • Tables and graphs included • Findings address research objectives stated

  17. Discussion • Results validate authors hypothesis • Limitations discussed: • Not blinded • But similar protocol before, during, after • No difference at baseline in hemodynamics, myocardial tissue measures • Difference not likely due to bias • Plus all dogs treated w/ lipid emulsion survived, and non treated w/ saline survived • When to start tmt • Dose of bupivacaine used

  18. Discussion… • Authors suggest further research in lipid based resuscitation for treatment of bupivacaine-induced cardiac toxicity: • Optimum dose • Dosage regimen • Risks of rapid lipid emulsion infusions need study too

  19. Discussion… • Suggestion of possible benefit of Propofol • Known to suppress bupivacaine-induced seizures • Commonly formulated in a 10% lipid emulsion vehicle • Theoretically could be used before severe hypotention/cardiac depression • Standard dose 2 mg/kg Propofol only provides 3% of dose of lipid in study

  20. Editorial by Groban et al • Recommendations: • Bupivacaine-induced toxicity: • When CNS hyperactivity doesn’t cease • Barbiturates, BZ or propofol • Standard ACLS 1st for cardiac arrest • Vassopressin over Epi (? Less drug induced VF, less acidosis) • Amiodarone over lido • Initiation of lipid infusion at earliest sign of severe LA cardiotoxicity (difficulty in tmt, good safety profile of lipids)

  21. Editorial by Groban et al… • Recommendations: • Bupivacaine-induced toxicity: • If no lipid infusion available, and standard ACLS NOT working…try propofol • Animal experiments needed • Propofol as “antidote” • Tread w/ caution…negative ionotrope • Propofol for sedation in surgery under regional anesthesia may reduced susceptibility to LA-induced toxicity

More Related