local anesthetic toxicity chuck magich, ms, crna staff nurse anesthetist r adams cowley, shock...
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Local Anesthetic Toxicity
Chuck Magich, MS, CRNAStaff Nurse Anesthetist
R Adams Cowley, Shock Trauma CenterBaltimore, MDOctober 2013
Used in epidural catheters & peripheral nerve block catheters.
“caine” family: Lidocaine Bupivicaine
Physiology
Local anesthetics block Na+ channels to prevent impulse transmission.
Meant for perineuronal injection, not IV!
Can bind to other receptors, especially cardiac.
More about Locals• Bolus at insertion 20-40 cc’s
• Infusion rates 5-10cc’s /hr
• Epi used in local to detect intravascular injection (HTN, tachy)
• Epi also used to prolong duration of action by causing vasoconstriction to area infiltrated
• Always aspirate before injecting
• Small incremental injections
Signs & symptoms of toxicity
CNS Dizziness Circumoral numbness Tinnitus Metallic taste Confusion Seizure Coma
Cardiovacular Hypotension Bradycardia Heart Block Vent Arrythmias V-tach V-Fib Asystole
Traditional Management of Toxicity
BLS ACLS
CPB Often prolonged
resus w/poor outcomes
First discovered in 1998 by Weinberg First used to successfully treat patient in
2006 (Rosenblatt) Now being shown to be effective for other
types of OD’s: TCA’s, beta blockers, calcium channel blockers
History of Lipid Rescue
Rat Experiment
http://youtu.be/b70Li9r3pL8
http://youtu.be/B3au3aKU4oE
Lipid Rescue Protocol
105 cc’s IV push
1050 cc/hr
Calculations
70 Kg patient:1. Bolus dose?2. Infusion rate
(cc/hr)?
Notify pharmacy ASAP!
“Rule of 15:” Bolus = 1.5
0.25ml/kg/min = 15 X wt(kg) = cc/hr
How it works
“Partitioning”:• Lipid Sink• Lipid Pool• Lipid
Sponge
Location
Available at all satellite pharmacy windows:• GOR• 3rd floor old trauma
building
Hospital-wide date TBA
Currently in large omnicell just outside New TOR entrance
Once hospital wide, only in key omnicells, not every one.
What & Where?
Contents:1. 20% Intralipid
(500ml)2. Alaris pump tubing3. Copy of protocol
• 84 y/o, ASA 2, 70 kg• Femoral neck fx• Block w/ 30cc 0.25%
Bupivicaine• Neg asp after every 5 cc• c/o feeling “funny” 1 min
after block• Became unresponsive
followed by seizure• Developed PEA arrest• Intubated & CPR started• 1mg epi given• 20% intralipid started
within 5-8 mins after LOC• Rec’d 500 ml lipid total
• Soon after lipid started developed SB 35
• Atropine 0.5mg x 2• Ext pacing started• HR 70 w/stable BP• To ICU on no pressors• 24* later hemiarthroplasty
performed• Extubated end of case• DC to floor 3 days later• Completely neurologically
intact
Case Study
Websites:
1. http://lipidrescue.org2. http://www.lipidrescue.c
om
Need to Know More???
LIPID RESCUE APP
1. http://lipidrescue.org2. http://www.lipidrescue.com3. Weinberg, GL (2012). Lipid Emulsion Infusion:
Resuscitation for Local Anesthetic and Other Drug Overdose. Anesthesiology 2012; 117 (1), pp. 180-187.
4. Hiller, DB; Gregorio, GD; Ripper, R; Kelly, K; Massad, M; Edelman, L; Edelman, G; Feinstein, DL; Weinberg, GL. Epinephrine Impairs Lipid Resuscitation from Bupivacaine Overdose: A Threshold Effect. Anesthesiology 2009: 111 (3), pp.498-505.
References