Local anesthetic systemic toxicity: Difference between revisions
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==Background== | ==Background== | ||
* | *Life-threatening adverse reaction to local anesthetic toxicity. | ||
**0.2% of nerve blocks | *Cases<ref name="Fencl">Fencl JL. Local anesthetic systemic toxicity: perioperative implications. AORN J. 2015 Jun;101(6):697-700.</ref> | ||
* | **Injection of local anesthetic into systemic circulation | ||
**Exceeding the maximum dose of local anesthetic (see table below) | |||
**Absorption of anesthetic into systemic circulation by injection into extremely vascular area. | |||
*Incidence = ~0.2% of nerve blocks | |||
*Generally occurs within minutes of injection | |||
{{Maximum doses of anesthetic agents}} | {{Maximum doses of anesthetic agents}} | ||
==Clinical Features== | ==Clinical Features== | ||
*CNS symptoms | *CNS symptoms (typically occur before CVS symptoms<ref name="Fencl" />) | ||
**Agitation | **Agitation | ||
**Auditory changes | **Auditory changes | ||
Line 15: | Line 18: | ||
**Coma | **Coma | ||
**Respiratory arrest | **Respiratory arrest | ||
*Cardiovascular | *Cardiovascular<ref name="Fencl" /> | ||
** | **Early signs | ||
***Tachycardia | ***Tachycardia | ||
***Ventricular dysrhythmia | ***Ventricular dysrhythmia | ||
***Hypertension | ***Hypertension | ||
** | **Late signs | ||
***Bradycardia | ***Bradycardia | ||
***Conduction block | ***Conduction block | ||
***Cardiovascular collapse | |||
***[[Asystole]] | ***[[Asystole]] | ||
Revision as of 07:54, 16 July 2015
Background
- Life-threatening adverse reaction to local anesthetic toxicity.
- Cases[1]
- Injection of local anesthetic into systemic circulation
- Exceeding the maximum dose of local anesthetic (see table below)
- Absorption of anesthetic into systemic circulation by injection into extremely vascular area.
- Incidence = ~0.2% of nerve blocks
- Generally occurs within minutes of injection
Maximum Doses of Anesthetic Agents
Agent | Without Epinephrine | With Epinephrine | Duration | Notes |
Lidocaine | 5 mg/kg (max 300mg) | 7 mg/kg (max 500mg) | 30-90 min |
|
Mepivicaine | 7 mg/kg | 8 mg/kg | ||
Bupivicaine | 2.5 mg/kg (max 175mg) | 3 mg/kg (max 225mg) | 6-8 hr |
|
Ropivacaine | 3 mg/kg | |||
Prilocaine | 6 mg/kg | |||
Tetracaine | 1 mg/kg | 1.5 mg/kg | 3hrs (10hrs with epi) | |
Procaine | 7 mg/kg | 10 mg/kg | 30min (90min with epi) |
Clinical Features
- CNS symptoms (typically occur before CVS symptoms[1])
- Agitation
- Auditory changes
- Metallic taste
- Seizures or drowsiness
- Coma
- Respiratory arrest
- Cardiovascular[1]
- Early signs
- Tachycardia
- Ventricular dysrhythmia
- Hypertension
- Late signs
- Bradycardia
- Conduction block
- Cardiovascular collapse
- Asystole
- Early signs
Differential Diagnosis
- Anaphylaxis
- Anxiety
Diagnosis
- Clinical diagnosis
Workup
- Directed by clinical picture
- Blood levels of anesthetic are available, but not clinically useful.
Management
- Lipid emulsion, 20% solution
- 1.5 mL/kg bolus over 1 minute
- Then, 15 mL/kg per hour x 20-minute infusion (0.25 mL/kg/min for 20 min or until hemodynamic stability)
- Manage seizures with benzodiazepines; propofol is an option but may worsen CV toxicity
- ACLS modifications per ASRA (Am Soc of Regional Anesthesia):
- Small initial doses of 100 μg boluses in adults
- No vasopressin
- Avoid CCBs and BBs
- Amiodarone preferred in ventricular dysrhythmias
See Also
External Links
Medscape:Local Anesthetic Toxicity