General: The process of experiencing respiratory impairment from submersion/immersion in liquid. There are three outcomes:

• Drowning without morbidity. 
• Drowning with morbidity. 
• Drowning with death. 
• Terms like near-drowning, dry-drowning, etc. are no longer used. 

Epidemiology: #1 cause of death in 1-4 year olds.

Pathophysiology: breathholding followed by involuntary gasps > aspiration and laryngospasm > loss of consciousness > active aspiration leading to loss of surfactant, atelectasis, V/Q mismatch and ARDS. Generally, there is respiratory arrest and tachycardia followed by bradycardia, PEA and asystole.

Clinical: Think about what caused the drowning; Trauma v. intoxication v. seizure v. cardiac arrhythmia/ syncope.

Management

• Pre-Hospital:
• if unconscious but breathing, place in lateral decubitus position.
• if unconscious and not breathing, administer rescue breaths.
• if unconscious, not breathing and without pulses use usual BLS and ACLS with a emphasis and "ABC's" instead of "CAB's".
• Heimlich Maneuver is not indicated.

Evaluation:

• HPI and Exam + CXR + observation x 8 hours and repeat CXR prior to discharge; consider EKG to evaluate for long QTc or other cardiac etiology as source.
• Mild - asymptomatic patient with a normal exam, normal SaO2 and normal CXR can be discharged.
• Moderate - symptomatic patient or abnormal SaO2; admit for observation.
• Severe - requiring BiPAP or intubation; lung protective strategy, ARDS management, ECMO; ICU.
• Manage hypothermia and consider C-Collar if evidence of trauma or traumatic mechanism.
• No prophylactic antibiotics are indicated unless drowning occured in very dirty water.
• Provide infectious return to ER precautions. 
• No steroids are indicated

References:

Szpilman, D., Bierens, J. J., Handley, A. J., & Orlowski, J. P. (2012). Drowning. N Engl J Med, 366(22), 2102-2110. doi: 10.1056/NEJMra1013317