Rosen & Barkin's 5-Minute Emergency Medicine Consult (732 page)

• ABCs:
  
  • Low threshold to intubate patients with altered mental status
    
• IV 0.9% normal saline (NS)
  
• Oxygen
  
• Cardiac monitor:
  
  • For wide-complex rhythm (QRS >100–120 ms) bolus sodium bicarbonate
    
• Naloxone, thiamine, glucose (Accu-Chek) for altered mental status
  
• Flumazenil contraindicated in combined TCA/benzodiazepine overdose
  

• Initiate therapy for cardiac toxicity aggressively to prevent deterioration.
  
• QRS widening (>100–120 ms):
  
  • Bolus with 1 amp (peds: 1–2 mEq/kg) of sodium bicarbonate; repeat if sudden increase in QRS width
    
  • Maintain arterial pH of 7.45–7.5 with hyperventilation.
    
  • Initiate sodium bicarbonate infusion if hyperventilation alone does not reach target pH.
    
• Dysrhythmia:
  
  • Sinus tachycardia requires no treatment.
    
  • Bolus 1–2 amps of sodium bicarbonate (1–2 mEq/kg in children) for sudden change in rhythm
    
  • Follow advanced cardiac life support (ACLS) protocol with addition of sodium bicarbonate boluses:
    
    • Lidocaine is 2nd-line agent after sodium bicarbonate.
      
  • Use of class IA (procainamide) and IC agents and physostigmine contraindicated
    

• 0.9% NS fluid bolus
  
• Norepinephrine:
  
  • Preferred pressor (over dopamine)
    
  • Counters α-blockade better
    
  • Dopamine requires higher doses.
    

• Gastric lavage:
  
  • For recent ingestion (<1 hr)
    
  • Performed when airway has been secured in lethargic patient
    
• Administer activated charcoal with sorbitol.
  
• Ipecac contraindicated
  

• Diazepam 1st-line followed by phenobarbital
  
• Neuromuscular paralysis with short-acting agent (rocuronium/vecuronium) for refractory seizures (monitor EEG)
  
• Sodium bicarbonate bolus to prevent acidosis
  

• Sodium bicarbonate: 1–2 amps (50–100 mEq) IV push (peds: 1–2 mEq/kg)
  
• Activated charcoal slurry: 1–2 g/kg up to 90 g PO
  

• Dextrose: D
  ₅₀
  W, 1 amp: 50 mL or 25 g (peds: D
  ₂₅
  W, 2–4 mL/kg) IV
  
• Diazepam (benzodiazepine): 5–10 mg (peds: 0.2–0.5 mg/kg) IV
  
• Dopamine: 2–20 μg/kg/min IV infusion titrated to desired effect
  
• Intralipid fat emulsion 20%: 1.5 mL/kg IV followed by 0.25 mL/kg/min (experimental for patients refractory to bicarbonate). Call Poison Control Center for guidance.
  
• Lorazepam (benzodiazepine): 2–6 mg (peds: 0.03–0.05 mg/kg) IV
  
• Naloxone (Narcan): 2 mg (peds: 0.1 mg/kg) IV or IM initial dose
  
• Norepinephrine: 4–12 μg/min (peds: 0.05–0.1 μg/kg/min) IV infusion titrated to desired effect
  

FOLLOW-UP

• Symptomatic patients observed >6 hr
  
• Altered mental status
  
• Dysrhythmia or conduction delay
  
• Seizure
  
• Heart rate >100 beats/min 6 hr after ingestion
  
• Coingestion requiring prolonged observation
  

• Asymptomatic after 6-hr observation
  
• No alteration in mental status
  
• Normal ECG with heart rate <100 beats/min
  
• Active bowel sounds; tolerated, activated charcoal
  
• Psychiatry clearance if there has been suicide attempt or gesture
  

Toxicology or poison center consultation for significant ingestions

Psychiatry for suicide attempts

• The hallmark of TCA poisoning is rapid clinical deterioration.
  
• Vigilant monitoring for QRS widening beyond 120 ms is essential.
  
• Achieve target pH with hyperventilation in the intubated TCA overdose patient.
  
• Treat acute widening of the QRS beyond 120 ms with bolus bicarbonate.
  

• Blaber MS, Khan JN, Brebner JA, et al. “Lipid rescue” for tricyclic antidepressant cardiotoxicity.
  J Emerg Med
  . 2012;3:465–467.
  
• Geis GL, Bond GR. Antidepressant overdose: Tricyclics, selective serotonin reuptake inhibitors, and atypical antidepressants. In: Erickson TB, Ahrens W, Aks SE, et al., eds.
  Pediatric Toxicology
  . New York, NY: McGraw-Hill; 2004:297–302.
  
• Reilly TH, Kirk MA. Atypical antipsychotics and newer antidepressants.
  Emerg Med Clin North Am
  . 2007;25:477–497.
  
• Woolf AD, Erdman AR, Nelson LS, et al. Tricyclic antidepressant poisoning: An evidence-based consensus guideline for out-of-hospital management.
  Clin Toxicol (Phila)
  . 2007;45:203–233.
  

See Also (Topic, Algorithm, Electronic Media Element)

Antidepressant Poisoning

CODES

969.05 Poisoning by tricyclic antidepressants

BASICS

• The trigeminal nerve (cranial nerve [CN] V) innervates the face, oral mucosa, nasal mucosa, and cornea with its sensory fibers
  
• Trigeminal neuralgia is also known as tic douloureux:
  
  • Tic = spasmodic muscular contraction or movement
    
  • Douloureux = painful
    
• Usually occurs in patients >50 yr of age
  
• Facial pain syndrome recognizable by history alone
  
• Classical:
  
  • Paroxysmal attacks of unilateral (uncommonly bilateral) pain affecting 1 or more divisions of the trigeminal nerve
    
  • Has 1 of the following characteristics:
    
    • Superficial, sharp, or stabbing pain
      
    • Precipitated from trigger areas or factors
      
  • Lasts for <1 sec–2 min
    
  • Episodes are stereotyped in each individual
    
  • No clinically evident neurologic deficit
    
  • Not caused by another disorder
    
• Symptomatic:
  
  • Same as above but a causative lesion (not vascular compression) is identified
    
• Most common age group is 50–60 yr
  
• Females > males
  

• Mechanism of pain production remains controversial; accepted theory suggests:
  
  • Demyelination of CN, leading to ectopic stimulation and pain:
    
    • Demyelination caused by tortuous or aberrant vascular compression of nerve root
      
    • 80–90% of classical trigeminal neuralgia have compression
      
    • Superior cerebellar artery is the most common (75%)
      
    • Anterior inferior cerebellar artery (10%)
      
• Secondary causes:
  
  • Herpes zoster
    
  • Multiple sclerosis
    
  • Space-occupying lesions:
    
    • Cerebropontine angle tumor
      
    • Aneurysm
      
    • Arteriovenous malformation
      

DIAGNOSIS

• Brief, intense, recurrent sharp pain
  
• Often described as “electric like”
  
• Unilateral in the distribution of a branch of the trigeminal nerve:
  
  • Can occur in all 3 nerves: Maxillary > mandibular > ophthalmic
    
• More common on right side of face
  
• May occur without provocation, but triggers can be produced by talking, smiling, chewing, brushing teeth, shaving, or touching the face:
  
  • Touch and vibration are the most common stimulus
    
• Can occur infrequently or hundreds of times per day
  
• No pain between episodes, although chronic cases may complain of a continuous ache
  

• Rule out possible symptomatic causes with the following atypical features:
  
  • Abnormal neurologic exam
    
  • Abnormal oral/dental exam
    
  • Abnormal ear exam or hearing loss
    
  • Symptoms of dizziness, vertigo, visual changes, or numbness
    
  • Pain lasting >2 min
    
  • Not in trigeminal nerve distribution