Understanding Drowning
The World Health Organization defines drowning as the process of experiencing respiratory impairment from submersion or immersion in liquid. This definition encompasses the full spectrum from mild aspiration to death. Previous terms like "near-drowning," "wet drowning," and "dry drowning" have been abandoned in favor of describing outcomes along a continuum. Drowning is the third leading cause of unintentional injury death worldwide and disproportionately affects children under 5 and young males ages 15 to 24.
The primary pathophysiology of drowning is hypoxia. When a person submerges, voluntary breath-holding eventually gives way to involuntary aspiration of water. Laryngospasm may occur initially but relaxes as hypoxia worsens, allowing water aspiration. Aspirated water disrupts surfactant in the alveoli, causing atelectasis, ventilation-perfusion mismatch, and progressive hypoxemia. The distinction between freshwater and saltwater drowning, while physiologically different, is clinically irrelevant in the prehospital setting because management is the same.
Scene Safety and Rescue
The first priority in any water emergency is rescuer safety. More than one drowning has been caused by a rescuer becoming a victim. Follow the "reach, throw, row, go" hierarchy: reach to the patient with a pole or hand from a stable surface, throw a rope or flotation device, row to the patient in a boat, and enter the water only as a last resort with proper training and equipment. Never attempt a swimming rescue unless you are trained as a water rescue swimmer with appropriate PPE.
Once the patient is out of the water, initiate resuscitation immediately. If the patient is not breathing, begin rescue breathing while still in shallow water if it is safe to do so. Chest compressions require a firm surface, so they must wait until the patient is on land or in a boat. Suspect cervical spine injury in diving accidents, jumps into shallow water, and when the mechanism is unknown, but do not delay resuscitation for spinal precautions.
Prehospital Management
Management of drowning patients follows standard resuscitation priorities with emphasis on airway and oxygenation:
- Airway: Suction any water, vomit, or debris from the airway. Position for drainage. Drowning patients frequently vomit during resuscitation, so have suction ready continuously.
- Breathing: Provide high-flow oxygen by nonrebreather mask for spontaneously breathing patients. For apneic patients, initiate BVM ventilation. Expect increased resistance due to water in the lungs; use higher pressures cautiously to avoid gastric distension.
- Circulation: Begin CPR for pulseless patients. Follow standard ACLS/BLS protocols. Note that hypothermic drowning patients may have very faint pulses; spend up to 60 seconds checking for a pulse before initiating compressions.
Special Considerations
Cold water submersion offers some neuroprotective benefit, especially in young children. There are documented cases of complete neurological recovery after prolonged submersion in cold water (below 70 degrees F). For this reason, resuscitation efforts should be prolonged for cold water drowning victims. All drowning patients who had any respiratory symptoms should be transported for observation, as delayed pulmonary edema (previously called "secondary drowning") can develop 2 to 24 hours after the event. Even patients who appear completely asymptomatic at the scene should be evaluated at the hospital.