Decompression sickness

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Background

  • Also known as "the bends"
  • Dissolved nitrogen (and occasionally helium) comes out of solution and forms bubbles in blood and tissue

Clinical Features

  • Symptom typically start soon after surfacing
    • 42% in 1 hr, 60% in 3 hr, and 98% in 24 hr[1]
    • CNS cases present more rapidly – 56% within 10 mins[2]
    • Some symptoms can be delayed for days[3]

Type I (Pain only DCS)

  • Involves the joints, extremities, skin (livedo reticularis/cutis marmorata), and constitutional symptoms
  • 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") involvement
    • 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

Scuba Diving Emergencies

Workup

Decompression sickness is a clinical diagnosis

  • In patients that are ambiguous or decompensated, consider additional workup 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

Management

Treatment based almost solely on case reports and series

  • ABCs/BLS/ACLS
  • 100% NRB regardless of SpO2
  • Keep supine, Trendelenburg not recommended[4]
  • Hyperbaric oxygen
    • Effective even in delayed cases
    • Do not wait for recompression, but if delayed presentation, may recompress up to 14 days after symptom onset[5][6]
  • Contact Divers Alert Medicine (DAN) at 1-800-446-2671
    • Similar function as to poison control
  • Consider adjuncts

Disposition

  • Hyperbaric chamber and admission

Prognosis

  • One study showed at an average of 6.1 yrs, almost 50% of patients had impairments[7]
    • These include impaired urination, defication, and sexual function

See Also

External Links

References

  1. ↑ Navy Department. US Navy Diving Manual. Revision 6. Vol 5: Diving Medicine and Recompression Chamber Operations. NAVSEA 0910-LP-106-0957. Washington, DC: Naval Sea Systems Command, 2008.
  2. ↑ Francis TJ, et al. Central nervous system decompression sickness: latency of 1070 human cases. Undersea Biomed Res. 1988; 15:403–417.
  3. ↑ Freiberger JJ, et al. The relative risk of decompression sickness during and after air travel following diving. Aviat Space Environ Med. 2002; 73:980–984.
  4. ↑ Moon RE, ry sl. Guidelines for treatment of decompression illness. Aviat Space Environ Med. 1997; 68:234–243.
  5. ↑ Marx et al. Rosen's Emergency Medicine - Concepts and Clinical Practice. 8th Ed. 2013. Ch 143. Pg. 1925.
  6. ↑ Edmonds C et al. Diving and Subaquatic Medicine, Fifth Edition. 2015. Decompression Sickness: Treatments. Pg 173.
  7. ↑ Vann RD, et al. Decompression illness. Lancet. 2011; 377(9760):153-164.
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