CMC COMPENDIUM
  • RESIDENCY
    • About CMC
    • Curriculum
    • Benefits
    • Explore Charlotte
    • Official Site
  • FELLOWSHIP
    • EMS
    • Global EM
    • Pediatric EM
    • Toxicology >
      • Tox Faculty
      • Tox Application
    • (All Others)
  • PEOPLE
    • Program Leadership
    • PGY-3
    • PGY-2
    • PGY-1
    • Alumni
  • STUDENTS/APPLICANTS
    • Medical Students at CMC
    • EM Acting Internship
    • Healthcare Disparities Externship
    • Resident Mentorship
  • #FOAMed
    • EM GuideWire
    • CMC Imaging Mastery
    • Pediatric EM Morsels
    • Blogs, etc. >
      • CMC ECG Masters
      • Core Concepts
      • Cardiology Blog
      • Dr. Patel's Coding Blog
      • Global Health Blog
      • Ortho Blog
      • Pediatric Emergency Medicine
      • Tox Blog
  • Chiefs Corner
    • Top 20
    • Current Chiefs
    • Schedules >
      • Conference/Flashpoint
      • Block Schedule
      • ED Shift Schedule
      • AEC Moonlighting
      • Journal Club/OBP/Audits Schedule
      • Simulation
    • Resources >
      • Fox Reference Library
      • FlashPoint
      • Airway Lecture
      • Student Resources
      • PGY - 1
      • PGY - 2
      • PGY - 3
      • Simulation Reading
      • Resident Wellness
      • Resident Research
      • Resume Builder
    • Individualized Interactive Instruction

Propofol As Intralipid Therapy??

9/16/2015

1 Comment

 
20% intravenous fat emulsion (IFE) may be useful to resuscitate severe cardiotoxicty due to fat-soluble drugs; the so-called lipid rescue. Propofol is a fat soluble anesthetic agent that is formulated and delivered in 3% IFE. If 20% IFE is not immediately available, can I use propofol as a substitute for 20% IFE?

What is Intravenous Lipid Emulsion?
  • Also called ILE, Lipid resuscitation therapy (LRT), LipidRescue, or Intralipid
  • Composed of  medium- and long-chain triglycerides, free fatty acids, and phospholipids
  • Is a component of TPN

How does it work?
  • Think of lipid rescue as dialysis for lipophilic drugs. IFE acts as a lipid sink, sequestering fat soluble drugs away from critical organ tissue
  • Has shown promise in rat and dog models for treating lipid-soluble cardiotoxins 
  • First successful clinical case report in 2006 - patient arrested immediately after interscalene block with bupivacaine and mepivacaine - after 20 min of ACLS, gave 100mL of Intralipid and had pulse/BP within a few minutes
  • Theory of the “lipid sink”: draws medications into the lipid sink and away from target organs, but multiple theories exist 
Picture
What can it treat?
  • ACMT says that there is no “standard of care” for this treatment yet
  • Considered if patient is hemodynamically unstable from a substance with high lipid solubility and patient is unresponsive to standard therapies
  • Local anesthetics have a more clear indication
  • Other possible substances described in case reports: calcium-channel blockers, beta blockers, TCAs, antipsychotics, bupropion, chloroquine, glyphosate, and cocaine

How do you give it?
  • 20% lipid emulsion (e.g. Intralipid) given as 1.5 ml/kg bolus over 2-3 minutes. 
  • Follow immediately with infusion of Intralipid at a rate of 0.25 ml/kg/min
  • May repeat bolus if patient remains in asystole or PEA 
  • May increase infusion or even re-bolus if after an initial response, patient becomes unstable again
  • Therapy should be stopped after 1 hour, or less, if the patient’s clinical status permits

Are there any adverse reactions?
  • ILE has been associated with pancreatitis, fever, hematuria, and DVT
  • Just like TPN - also associated systemic infections, especially fungemia 
  • Animal studies show risk of acute lung injury

What lab tests are altered?
  • AST
  • Hgb
  • Met-Hgb
  • Electrolytes
  • Coags
  • ABG
  • ASA? unknown

Why do people think Propofol will work?
  • Propofol is in a medium/large chain triglyceride lipid emulsion, so it is also a fat emulsion, just like ILE
  • However there have been some misquoted studied that lead people to believe that Propofol has proven efficacy as an antidote 
  • One article that studied pressors (epinephrine and vasopressin for bupivacaine induced cardiac arrest in pigs) misquoted a study by Dr. Weinberg (MD behind “Lipid Rescue”) and stated that propofol treats bupivacaine toxicity
  • Dr. Weinberg refuted this misquote in an editorial: “We have never recommended use of propofol for treating bupivacaine overdose, and strongly suspect that its use in cardiac arrest will impede resuscitation”​

Have any studies been performed?
  • Ohmura 1999: In pigs: propofol vs sevoflurane 
  • Higher doses of bupivacaine in propofol group to induce dysrhythmias, seizures, or 50% reduction of heart rate
  • Zimmer 2007: Case report:  patient received BOTH propofol and intralipid
  • Mauch 2011: In piglets: propofol with sevoflurane vs sevoflurane alone.  No change in toxic dose of bupivacaine between the groups
  • Yilmaz 2014: Rat study with different preparations of propofol, propofol in intralipid, propofol in medialipid, or saline.  
                       * End points of: time to first dysrhythmia, times to 25% and 50% reduction in HR or BP, and time to asystole

                      * Propofol in intralipid group had longer time to each adverse outcome than the other groups
  • Güngör 2015: Case report - 76 y.o. female had interscalene block with bupivacaine. Patient became unresponsive and seized, thus was intubated with thiopental and atracurium. Propofol infusion was started. 
  • Bupivacaine levels were drawn just after intubation (1.6) and at the conclusion of the surgical case (undetectable at 135 min). Toxic level is 2-4. In the study discussion the authors believe that the Bupivacaine should have still been detectable and attribute this decrease to the propofol. 

What did I take away from this?
  • Propofol has only been studied in animals or case reports
  • Many of these are giving intralipid with propofol
  • NEVER been used/studied in anything other than local anesthetic toxicity
  • In severe toxicities that involve hemodynamic collapse (indication for lipid emulsion therapy), giving a medication that causes hypotension doesn’t seem to make sense

References:
  • Antidotes For Overdose: Timely And Effective Counteraction, EM critical care, July 2014
  • American College of Medical Toxicology (ACMT) National Office -  Interim guidance for the use of lipid resuscitation therapy
  • Rosenblatt MA, Abel M, Fischer GW, et al. Successful use of a 20% lipid emulsion to resuscitate a patient after a presumed bupivacaine-related cardiac arrest. Anesthesiology. 2006;105(1):217-218.
  • Mauch J, Kutter AP, Martin Jurado O, Spielmann N, Frotzler A, Bettschart-Wolfensberger R, Weiss M. [Bupivacaine toxicity and propofol anesthesia : animal study on intravascular bupivacaine injection]. Anaesthesist.  2011 Sep;60(9):814-8. doi: 10.1007/s00101-011-1898-8. Epub 2011 Jul 3. German. PubMed PMID: 21725675.
  • Zimmer C, Piepenbrink K, Riest G, Peters J. [Cardiotoxic and neurotoxic effects after accidental intravascular bupivacaine administration. Therapy with lidocaine propofol and lipid emulsion]. Anaesthesist. 2007 May;56(5):449-53. German. PubMed PMID: 17277955.
  • Weinberg G, Hertz P, Newman J. Lipid, not propofol, treats bupivacaine overdose. Anesth Analg. 2004 Dec;99(6):1875-6; author reply 1876. PubMed PMID: 15562099.
  • A Comparison of Epinephrine and Vasopressin in a Porcine Model of Cardiac Arrest After Rapid Intravenous Injection of Bupivacaine, Mayr, Viktoria
  • Güngör İ, Akbaş B, Kaya K, Çelebi H, Tamer U. Sudden developing convulsion during interscalene block: Does propofol anesthesia diminish plasma bupivacaine level? Agri. 2015 Jan;27(1):54-7. doi: 10.5505/agri.2015.82160. PubMed PMID: 25867875.
  • Ohmura S, Ohta T, Yamamoto K, Kobayashi T. A comparison of the effects of propofol and sevoflurane on the systemic toxicity of intravenous bupivacaine in rats. Anesth Analg. 1999 Jan;88(1):155-9. PubMed PMID: 9895084
  • Yilmaz M, Celebi H, Akcali D, Gurel N. Pre-treatment of bupivacaine-induced cardiovascular depression using different lipid formulations of propofol. Acta Anaesthesiol Scand. 2014 Mar;58(3):298-302. doi: 10.1111/aas.12263. Epub 2014 Jan 20. PubMed PMID: 24438483
1 Comment

    Toxicology Blog

    Picture

    Author

    EM Rotators on Toxicology

    Selected by Feedspot as one of the Top 20 Toxicology Blogs on the web
    Subscribe to Tox Blog Emails

    Archives

    March 2018
    November 2017
    October 2017
    August 2017
    April 2016
    November 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015

    Categories

    All
    Bath Salts
    Domoic Acid
    Etomidate
    Herbals
    Intralipid Therapy
    Mercury
    Overdose
    Precedex
    Propofol
    SSRI

    Disclaimer: All images included on this blog are the sole property of CMC EM Residency and cannot be used or reproduced without written permission.  Patient identifiers have been redacted/changed or patient consent has been obtained.  Information contained in this blog is the opinion of the author and application of material contained in this blog is at the discretion of the practitioner to verify for accuracy.

    RSS Feed

Powered by Create your own unique website with customizable templates.
  • RESIDENCY
    • About CMC
    • Curriculum
    • Benefits
    • Explore Charlotte
    • Official Site
  • FELLOWSHIP
    • EMS
    • Global EM
    • Pediatric EM
    • Toxicology >
      • Tox Faculty
      • Tox Application
    • (All Others)
  • PEOPLE
    • Program Leadership
    • PGY-3
    • PGY-2
    • PGY-1
    • Alumni
  • STUDENTS/APPLICANTS
    • Medical Students at CMC
    • EM Acting Internship
    • Healthcare Disparities Externship
    • Resident Mentorship
  • #FOAMed
    • EM GuideWire
    • CMC Imaging Mastery
    • Pediatric EM Morsels
    • Blogs, etc. >
      • CMC ECG Masters
      • Core Concepts
      • Cardiology Blog
      • Dr. Patel's Coding Blog
      • Global Health Blog
      • Ortho Blog
      • Pediatric Emergency Medicine
      • Tox Blog
  • Chiefs Corner
    • Top 20
    • Current Chiefs
    • Schedules >
      • Conference/Flashpoint
      • Block Schedule
      • ED Shift Schedule
      • AEC Moonlighting
      • Journal Club/OBP/Audits Schedule
      • Simulation
    • Resources >
      • Fox Reference Library
      • FlashPoint
      • Airway Lecture
      • Student Resources
      • PGY - 1
      • PGY - 2
      • PGY - 3
      • Simulation Reading
      • Resident Wellness
      • Resident Research
      • Resume Builder
    • Individualized Interactive Instruction