Immediate Management of Accidental Intravenous Lidocaine Injection
Stop the injection immediately, assess for signs of toxicity, maintain airway/breathing/circulation, and have 20% lipid emulsion ready for administration according to local anesthetic systemic toxicity (LAST) protocols. 1
Immediate Actions (First 5 Minutes)
- Discontinue lidocaine administration immediately and preserve the pump/syringe with settings intact for later investigation 1
- Call for help and ensure resuscitation equipment, oxygen, and 20% lipid emulsion are immediately available 1, 2
- Establish continuous monitoring: ECG, pulse oximetry, and blood pressure every 5 minutes 1
- Maintain airway patency and ensure adequate ventilation/oxygenation, as acidosis accelerates toxicity 2, 3
Assess for Toxicity Signs
Early Neurological Signs (appear first at 5-10 μg/mL plasma concentration):
- Perioral tingling and numbness of tongue/lips 1, 3
- Tinnitus and auditory disturbances 1
- Light-headedness, dizziness, restlessness 1
- Slurred speech and facial flushing 1, 3
- Confusion and altered mental status 4, 5
Critical point: Neurological symptoms appear BEFORE cardiovascular signs, so ECG changes are late manifestations 1. Do not wait for cardiac symptoms to act. 1
Severe Toxicity Signs (at >10 μg/mL):
- Muscle twitching and tremors 1, 3
- Seizures/convulsions 1, 5, 3
- Loss of consciousness and coma 1, 3
- Respiratory arrest 1, 2, 3
- Cardiac arrhythmias, bradycardia, myocardial depression 1, 3
- Ventricular arrest and asystole 1, 3
Treatment Protocol
For Mild Toxicity (early neurological signs only):
- Administer 100% oxygen and support ventilation 2, 3
- Position patient supine with legs elevated 3
- Monitor continuously for progression to severe toxicity 1
- Do NOT give additional local anesthetics for at least 4 hours 1, 4
For Seizures:
- Administer benzodiazepines (midazolam 2-5 mg IV or diazepam 5-10 mg IV) as first-line treatment 5, 3
- Alternative: thiopental sodium if benzodiazepines fail 3
- Maintain oxygenation throughout seizure activity to prevent acidosis 2, 3
For Cardiovascular Collapse:
- Initiate 20% lipid emulsion immediately according to Association of Anaesthetists' LAST guidelines 1
- Bolus: 1.5 mL/kg IV over 1 minute
- Followed by infusion: 0.25 mL/kg/min
- Repeat bolus every 5 minutes up to 3 times if needed
- Continue infusion until hemodynamic stability achieved
- Begin standard ACLS protocols, but note that bupivacaine-induced arrest may be refractory to standard treatment 3
- Prolonged resuscitation may be necessary as lipid emulsion takes time to work 1
Laboratory and Documentation
- Draw blood immediately for lidocaine levels in both EDTA and lithium heparin tubes before treatment obscures results 1
- Document the dose administered, time of injection, and patient weight for toxicity assessment 1, 6
- Calculate total dose: Maximum safe dose without epinephrine is 4.5 mg/kg in adults 4
Special Considerations
High-Risk Patients (increased toxicity risk):
- Age >70 years 4
- Weight <40 kg 1, 4
- Hepatic disease (decreased metabolism) 2, 3
- Cardiac disease, heart block 2, 3
- Concurrent use of other local anesthetics 1, 4
- Patients on cimetidine, beta-blockers, or calcium channel blockers 3
These patients require even more aggressive monitoring and lower threshold for lipid emulsion administration. 4, 2
Common Pitfall to Avoid:
Do not rely solely on ECG monitoring, as cardiovascular toxicity is a late sign that appears after neurological symptoms. 1 Act on early neurological symptoms rather than waiting for cardiac changes. 1