All Emergencies - Basic life support principles:

  1. Maintain an airway
  2. Assess breathing
  3. Monitor circulation
Monitor and record all vital signs.
Local Anesthetic Reactions

Differential diagnosis:

  • Hyperventilation: Highly anxious, light-headed, fast respiration
  • Allergic reaction: Itching, wheezing, skin rash
  • Epinephrine overdose (Below)
  • Local anesthetic overdose: Anxious, tremor, heart palpitations (Below)


Epinephrine overdose:

  1. Terminate dental treatment.
  2. Position patient semi-upright
  3. ABC or BLS as indicated
  4. Manage symptoms
    1. Reassure patient
    2. Monitor vital signs
    3. Contact EMS if marked elevation in blood pressure or heart rate combined with headache & flushing
    4. Administer oxygen
    5. Recovery - patient will typically feel fatigued and depressed
    6. Optional: Administer vasodilator if blood pressure does not return to baseline level


Local Anesthetic Overdose:
Maximum dose of mepivacaine and lidocaine is 2mg/lb body weight (54 mg/cartridge).
Local anesthetic overdose frequently involves physically small patients.


Signs & Symptoms:

  1. Can become talkative, increased apprehension, slurred speech & stuttering.
  2. As the blood level of the overdose increases, muscles begin to twitch, and finally generalized convulsions develop.
  3. Since the muscle contractions release lactic acid into the bloodstream, seizures from local anesthetic overdose are frequently prolonged.


Management of local anesthetic overdose:

  1. PABC - Position, airway, breathing, circulation
  2. Manage this situation as you would with any patient having seizures.
  3. Activate the EMS if:
    1. Carotid pulse absent
    2. Immediately if seizure begins
    3. Unconsciousness that persists
  4. If patient is conscious, consider syncope from vasodepressor
  5. If patient is unconscious, consider allergic reaction.
    It is essential that allergic reactions be treated aggressively. In general, the faster the onset of symptoms, the more rapidly they will progress and the more severe the allergic reaction will become.
  6. Keep patient supine.
  7. Administer oxygen, maintain airway. Oxygenation & ventilation remove carbon dioxide from the blood, countering the acidosis that develops.
  8. The seizure will stop when the blood level of local anesthetic falls below the seizure threshold. Reassess the patient's airway, breathing & circulation
  9. Breathing may be depressed or absent. Blood pressure is usually low, heart rate rapid.
  10. Patients who have experienced a serious local anesthetic overdose will usually be hospitalized for observation and treatment.


Medications for Seizures

Lorazepam 2 mg/ml
Adults: 4 mg IV, given slowly, 2 mg/ml, may repeat q10-15 minutes
Pedo: 0.05 - 0.1 mg /kg, max 4 mg/dose