Drowning & Immersion

Drowning is the process of respiratory impairment from submersion or immersion in liquid. Outcomes are fatal or non-fatal drowning — older terms like “near-drowning”, “dry drowning”, “secondary drowning” and “wet drowning” are outdated and shouldn’t be used; they don’t change management. Not all water deaths are primarily drowning — sudden incapacitation (cardiac event, seizure, hypoglycaemia, decompression illness, drugs/alcohol) can cause a competent swimmer to lose consciousness in the water and should be suspected when drowning seems unexpected.

Rescue

Only attempt a rescue if it’s safe to do so — rescue from land or craft is safest; enter the water only with some form of flotation, and if entering isn’t safe, wait for rescue services. Throw something that floats (life-ring, lifejacket, buoyant object) to interrupt the drowning process while help arrives.

Spinal injury is rare in drowning but should be suspected after a dive into shallow water, dumping surf, rocks, or a boat/craft incident — even then, speed of rescue and airway management take priority over spinal precautions, and an unresponsive, not-breathing person should be removed from the water immediately by whatever means possible.

Assessment

Responsive after removal from water: minor incidents are often followed by coughing and return of normal breathing. Post-drowning complications resulting in death are rare, but everyone who required any treatment still needs health-professional assessment, discharge advice and — in some cases — observation, even if they appear fully recovered.

Unresponsive: assess on the back, head and body at the same level (not head-down) — this reduces regurgitation risk and is associated with better survival. Don’t routinely roll to the side to assess airway and breathing; only roll onto the side if the airway is obviously obstructed by fluid or debris, to let it drain by gravity, with minimal interruption to CPR. Don’t try to expel or drain frothy fluid that may re-accumulate in the airway during resuscitation, and don’t apply external pressure to empty a distended stomach.

Resuscitation

• Start CPR with rescue breaths for anyone unresponsive and not breathing normally — don’t delay for oxygen equipment or an AED. Chest-compression-only CPR is strongly discouraged in drowning (the primary problem is lack of oxygen, not a primary cardiac event) and should only be used temporarily if rescue breathing genuinely isn’t possible.
• AED: attach as soon as available and follow the prompts; dry the chest first if feasible. The rhythm is usually non-shockable, but the AED may still be lifesaving in the minority who are shockable. Defibrillation on a wet surface (e.g. poolside) is not dangerous.
• Oxygen: use if available for anyone with abnormal breathing, cyanosis, or after successful resuscitation, regardless of saturation — but don’t delay CPR waiting for oxygen equipment to arrive. Pulse oximetry can be unreliable in a wet or cold patient.
• In a hypothermic patient, extend pulse checks to 30 seconds (pulses may be weak) and treat gently — inappropriate compressions on an organised rhythm can precipitate a dysrhythmia. Both passive and active rewarming should be used; see Hypothermia for detail.

Disposition

Submersion duration is the single most important prognostic factor — mortality rises sharply once submersion exceeds 5 minutes. Everyone involved in a drowning incident needs an ambulance/assessment, even if they seem to have fully recovered, because post-drowning deterioration can occur in the following minutes to hours from lung and cardiac injury.

• Asymptomatic, normal oxygenation: drowning is primarily a clinical diagnosis — labs and imaging aren’t routinely needed in a well patient with normal oxygen saturation. Chest X-ray and blood gas are reasonable for persistent hypoxaemia or progressive respiratory symptoms, not routinely.
• Mild or no symptoms: observe (in an ED or equivalent monitored setting) for 4–8 hours; discharge with clear return precautions if stable throughout.
• Symptomatic: extended observation, with ward or ICU admission depending on severity.
• Watch for delayed pulmonary oedema — rarely, a patient with a normal initial chest X-ray develops fulminant pulmonary oedema within 12 hours (delayed ARDS, neurogenic oedema, or airway hyperreactivity), which is part of why even “recovered” patients need a period of observation rather than immediate discharge.

An alert or only mildly confused patient generally has a favourable prognosis; a comatose patient after resuscitation typically does not — hypoxic-ischaemic brain injury is the main driver of long-term morbidity after drowning, not the lung injury itself.

Prevention

Prevention is the most effective intervention in the Drowning Chain of Survival. Key messages for patients:

• Learn to swim.
• Always swim with others, in areas with lifeguards.
• Never enter the water after drinking alcohol.
• Know how and when to use a lifejacket.
• Enter unknown or shallow water feet-first.
• Supervise children in or near water constantly, including baths and buckets for infants. Pool fencing significantly reduces child drowning risk.

Learning first aid and CPR is itself a prevention measure, since it converts a bystander into someone who can interrupt the Chain of Survival early.