II. Epidemiology
- Accounts for 25% of annual fatalities in divers
III. Pathophysiology
- Gas enters the aorta and distributes to organs
- Most significant adverse effects occur with spinal or cerebral emboli (CVA) or coronary emboli (ACS)
- Neurologic symptoms predominate
- Vision Loss occurs when Retinal arteries are involved
- Small vessel emboli to Muscles or viscera tend to be well tolerated
IV. Causes
-
Barotrauma and lung hyperexpansion
- Scuba injury resulting from Pulmonary Barotrauma
- Blast Injury
- Cardiopulmonary bypass pump or Extracorporeal Membrane Oxygenation (ECMO)
-
Venous Thromboembolism
- Patent Foramen Ovale
- Massive embolism that enters arterial circulation
V. Symptoms
- When due to SCUBA, occurs within 5 minutes of ascent in 80% of cases
- Altered Level of Consciousness
- Unilateral motor deficits (14%)
- Visual disturbances and Acute Vision Loss (9%)
- Vertigo (8%)
- Unilateral sensory deficits (8%)
- Bilateral motor deficits (8%)
VI. Exam
-
Fundoscopy
- Retinal arterial gas bubbles
- Cardiovascular exam
-
Neurologic Exam
- Focal neurologic deficit
- Skin
- Skin mottling
VII. Differential diagnosis
- When due to Blast Injury
- Consider other direct Trauma (e.g. globe injury, Closed Head Injury)
VIII. Management
- Supplemental Oxygen (as close to 100% FIO2 as possible)
- Left lateral decubitus position (if possible)
- Replaces prior recommendations for trandelenburg position (head down position)
- Hyperbaric oxygen chamber
- Preferred definitive management
- Other measures
- Aspirin may reduce injury secondary to inflammation
- Monitor and treat associated conditions
IX. Resources
- Life in the Fast Lane
X. References
- Jagminas (2015) Crit Dec Emerg Med 29(5): 2-11
- Clenney (1996) Am Fam Physician 53(5):1761-6 [PubMed]
- Newton (2001) Am Fam Physician 63(11): 2211-2226 [PubMed]