Local Anesthetic Toxicity

Report
Local Anesthetic
Toxicity
Chuck Magich, MS, CRNA
Staff Nurse Anesthetist
R Adams Cowley, Shock Trauma Center
Baltimore, MD
October 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
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

Dizziness
Circumoral numbness
Tinnitus
Metallic taste
Confusion
Seizure
Coma




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
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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
History of Lipid Rescue
 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
Rat Experiment
http://youtu.be/b70Li9r3pL8
http://youtu.be/B3au3aKU4oE
Lipid Rescue Protocol
Calculations
70 Kg patient:
1. Bolus dose?
2. Infusion rate (cc/hr)?
105 cc’s IV push
1050 cc/hr
“Rule of 15:”
Bolus = 1.5
0.25ml/kg/min = 15 X wt(kg) = cc/hr
 Notify pharmacy ASAP!
How it works
“Partitioning”:
• Lipid Sink
• Lipid Pool
• Lipid Sponge
Location
Currently in large omnicell just outside New TOR entrance
 Available at all satellite
pharmacy windows:
• GOR
• 3rd floor old trauma
building
 Hospital-wide date TBA
 Once hospital wide, only in key omnicells, not every one.
Contents:
1. 20% Intralipid (500ml)
2. A l a r i s p u m p t u b i n g
3. C o p y o f p r o t o c o l
Case Study
• 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
Need to Know More???
Websites:
1. http://lipidrescue.org
2. http://www.lipidrescue.com
References
1. http://lipidrescue.org
2. http://www.lipidrescue.com
3. 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.

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