Decompression sickness

Background

• Dissolved inert gases (e.g. Nitrogen) come out of solution and form bubbles in blood and tissue

Clinical Features

Type I (Pain only DCS)

• Involves the joints, extremities, and skin ("cutis marmorata")
• Usually only single joint is involved

Type II (Serious DCS)

• Spinal cord involvement
  • Ascending paralysis
  • Signs often cannot be traced to single location in the cord (may have skip lesions)
    • Limb weakness, paresthesias, or paralysis
    • Urinary retention, fecal incontinence, or priapism
• Vestibular ("staggers") involvment
  • Vertigo, hearing loss, tinnitus
    • Differentiated from inner ear barotrauma which usually occurs on descent
• Pulmonary "chokes"
  • Cough, hemoptysis, dyspnea, substernal chest pain

Type III (Type II + gas embolism)

• Variety of stroke symptoms/signs
  • May spontaneously resolve

Differential Diagnosis

Diving Emergencies

• Barotrauma of descent
  • Otic barotrauma
  • Pulmonary barotrauma
  • Sinus barotrauma
  • Mask squeeze
  • Barodentalgia (trapped dental air causing squeeze)
• Barotrauma of ascent
  • Pulmonary barotrauma (pulmonary overpressurization syndrome)
  • Decompression sickness (DCS)
  • Arterial gas embolism
  • Alternobaric vertigo
  • Facial baroparesis (Bells Palsy)
• At depth injuries
  • Oxygen toxicity
  • Nitrogen narcosis
  • Hypothermia
  • Contaminated gas mixture (e.g. CO toxicity)
  • Caustic cocktail from rebreathing circuit

Workup

Decompression sickness is a clinical diagnosis

• In patients that are ambiguous or decompensated, consider additional w/u without delaying definitive treatment
• Other considerations
  1. Fingerstick
  2. CBC
  3. Chem10
  4. Lactate
  5. PT/PTT
  6. VBG (or ABG)
  7. Ethanol level
  8. Consider UDT

See Also

• Scuba diving emergencies