Rosen & Barkin's 5-Minute Emergency Medicine Consult (423 page)

EKG:

• Prolonged QT (most common)
  
• Nonspecific ST changes
  
• Premature ventricular contractions
  
• Atrial fibrillation
  
• Ventricular tachycardia
  
• Acute MI (rare)
  

Other causes of coma, cardiac dysrhythmias, or trauma:

• Hypoglycemia
  
• Intoxication
  
• Drug overdose
  
• Cardiovascular disease
  
• Cerebrovascular accident
  
• Seizure
  
• Syncope
  

TREATMENT

• Field triage should rapidly focus on providing ventilatory support to unconscious victims or those in cardiopulmonary arrest:
  
  • Prevents primary cardiac arrest from degenerating into hypoxia-induced secondary cardiac arrest
    
  • Conscious victims are at lower risk for imminent demise.
    
• Spine immobilization for:
  
  • Cardiopulmonary arrest (suspected trauma)
    
  • Significant mechanical trauma
    
  • Suspected loss of consciousness at any time
    
• Cover superficial burns with sterile saline dressings.
  
• Immobilize injured extremities.
  
• Rapid extrication to decrease risk for repeat lightning strikes
  

• ABCs
  
• Standard advanced cardiac life support measures for cardiac arrest
  
• Diligent primary and secondary survey for traumatic injuries and other causes of collapse/injury:
  
  • Maintain cervical spine precautions until cleared.
    
• Treat altered mental status with glucose, naloxone, or thiamine as indicated.
  
• Hypotension requires volume expansion, blood products, and/or pressor agents.
  

• IV access
  
• Cardiac monitor and pulse oximetry
  
• Clean and dress burns.
  
• Tetanus prophylaxis
  
• Treat myoglobinuria if present:
  
  • Diuretics, such as furosemide or mannitol
    
  • Alkalinize urine to a pH of 7.45 with IV sodium bicarbonate
    
• Volume expansion:
  
  • Do not follow burn treatment formulas because lightning burns are rarely the cause of fluid loss.
    
  • Occult deep burn injury is rare when compared with other types of electrical current injury.
    
  • Titrate volume administration to urine output.
    
  • Fluid loading may be dangerous if patient has concomitant head injury.
    
• Compartment syndrome:
  
  • Must be distinguished from vasospasm, autonomic dysfunction, and paralysis, which are usually self-limited phenomena.
    
  • Fasciotomy will rarely be necessary.
    
• NSAIDs and high-dose steroids have been proposed to reduce long-term neurologic and corneal damage.
  

• Furosemide: 1 mg/kg IV slow bolus q6h
  
• Mannitol: 0.5 mg/kg IV, repeat PRN
  
• Sodium bicarbonate: 1 amp IV push (peds: 1 mEq/kg) followed by 2–3 amps/L D5W IV fluid
  

FOLLOW-UP

• Postcardiac arrest patients
  
• History of change in mental status/altered level of consciousness
  
• History of chest pain, dysrhythmias, or ECG changes:
  
  • May not resolve spontaneously
    
  • 24–48 hr observation period to identify potentially unstable cases
    
  • Myoglobinuria
    
  • Acidosis
    
  • Extremity injury with or at risk for compartment syndrome
    

Asymptomatic patients with no injuries

• Close follow-up with subspecialists may be required due to the risk for delayed sequelae:
  
  • Neurology:
    
    • Memory deficit
      
    • Attention deficit
      
    • Aphasia
      
    • Sleep disturbance
      
    • Prolonged paresthesia and dysesthesias
      
  • Ophthalmology
    
  • ENT
    
• Psychology/psychiatry:
  
  • Anxiety
    
  • Depression
    
  • Personality changes
    
  • Post-traumatic stress disorder
    

• Do not follow burn treatment formulas for lightning burns and injuries.
  
• Be diligent in the primary and secondary survey so as not to miss occult injuries.
  
• Have a low threshold to admit and monitor patients with cardiopulmonary complaints, as unstable dysrhythmias may occur 24–48 hr post injury.
  

• Cooper MA, Andrews CJ, Holle RL. Lightning injuries. In: Auerbach PS, ed.
  Wilderness Medicine
  . 5th ed. St. Louis, MO: Mosby; 2007:67–108.
  
• Cooper MA, Holle RL. Mechanisms of lightning injury should affect lightning safety messages. 21st International Lightning Detection Conference. April 19–20, 2010; Orlando, FL.
  
• O’Keefe Gatewood M, Zane RD. Lightning injuries.
  Emerg Med Clin North Am
  . 2004;22(2):369–403.
  
• Price T, Cooper MA. Electrical and lightning injuries. In: Marx JA, Hockenberger RS, Walls RM, et al., eds.
  Rosen’s Emergency Medicine
  . 6th ed. Philadelphia, PA: Mosby; 2006.
  

See Also (Topic, Algorithm, Electronic Media Element)

Electrical Injury

CODES

• 949.0 Burn of unspecified site, unspecified degree
  
• 994.0 Effects of lightning
  
• 994.8 Electrocution and nonfatal effects of electric current
  

BASICS

• GI absorption is rapid:
  
  • Regular release: Peak serum levels 2–4 hr
    
  • Sustained release: Peak serum levels 4–12 hr
    
• Half-life 24 hr
  
• Slow distribution (at least 6 hr)
  
• Volume of distribution 0.6–0.9 L/kg
  
• Elimination:
  
  • Not
    metabolized
    
  • Renal excretion (unchanged)
    
  • Reabsorbed in the
    proximal
    tubules by sodium transport mechanism
    
  • Elimination half-life (therapeutic) is 20–24 hr and prolonged in chronic users
    
• Therapeutic and toxic indices:
  
  • Therapeutic and toxic effects occur
    only
    when lithium is intracellular
    
  • Narrow toxic-to-therapeutic ratio
    
  • Therapeutic level 0.6–1.2 mEq/L (postdistribution)
    
  • Because of small size, renal handling is similar to sodium, potassium, and magnesium
    
• Risk factors:
  
  • Acute conditions increasing risk of toxicity:
    
    • Dehydration (larger percent reabsorbed)
      
    • Overdose
      
  • Chronic conditions:
    
    • Hypertension
      
    • Diabetes mellitus
      
    • Renal failure
      
    • Congestive heart failure
      
    • Advanced age
      
    • Dose change
      
    • Drug interactions
      
    • Lithium therapy
      
    • Low-salt diet
      
  • The following may result in increased serum lithium levels due to decreased renal clearance or exacerbated effects:
    
    • NSAIDs
      
    • Thiazide diuretics
      
    • ACE inhibitors
      
    • Phenytoin
      
    • Tricyclic antidepressants
      
    • Phenothiazines
      

• Acute or chronic conditions affecting lithium clearance
  
• Overdose
  

DIAGNOSIS