Lidocaine Toxicity 


Lidocaine is metabolized by the liver

The therapeutic range is 1.5 to 5.0 mcg/mL

In higher doses and at toxic levels, the central nervous and respiratory systems will be affected.



Effects on Heart and Electrocardiogram (ECG)

  • Blocks sodium channels and slows conduction in atria and ventricles

  • Reduces automaticity in ventricles and bundle of His–Purkinje system

  • Accelerates repolarization

  • No significant impact on ECG


Signs and Symptoms of Toxicity

  • High and prolonged doses—drowsiness, confusion, paresthesias

  • Toxic doses—seizure, respiratory arrest


Treatment

  • Equipment for resuscitation (code cart)

  • Diazepam or phenytoin to be used for seizures

  • IV Lipid emulsion infusion


Nursing Implications


1. Assess level of consciousness and orientation.

2. Administer at the prescribed IV rate—administration that is too rapid can cause problems.

3. Protect for possible seizure activity; assess for paresthesia.

4. Check vital signs frequently.

5. Monitor ECG and report unusual activity or changes in rhythm.

6. Assess respiratory system, ventilation, and gas exchange (oxygen saturation).

7. Lidocaine preparations that contain epinephrine must never be administered IV; doing so can cause severe hypertension and life-threatening dysrhythmias. Lidocaine used for local anesthesia often contains epinephrine.



Excerpt From

Mosby's Pharmacology Memory NoteCards - E-Book | Find it here

JoAnn Zerwekh MSN, EdD, RN

Cheryl