Near Drowning

Near drowning (non-fatal drowning) is a process of respiratory impairment from submersion or immersion in liquid, in which the patient survives at least temporarily. Drowning is a leading cause of unintentional death worldwide, with over 200,000 deaths a year, most in low- and middle-income settings. Children aged 1 to 4 years and adolescent males are at highest risk, and most child deaths occur within sight of an adult.

Pathophysiology: breath-holding is followed by laryngospasm, then involuntary inhalation of water, hypoxemia and loss of consciousness, with cardiac arrest from hypoxia (asystole or pulseless electrical activity in most). Aspirated water washes out surfactant and damages the alveolar-capillary membrane, producing noncardiogenic pulmonary edema and acute respiratory distress syndrome. Fresh and salt water behave similarly in practice. Cold water adds hypothermia, which can protect the brain in children submerged in very cold water.

Risk factors: inability to swim, alcohol, seizures, cardiac arrhythmia (long QT syndrome and catecholaminergic polymorphic ventricular tachycardia in unexplained swimmer collapse), diving injury, cold shock and unsupervised access to water. Poor prognosis is predicted by submersion for over 10 minutes, delay in CPR, asystole, fixed pupils, pH under 7.0 and water over 6 degrees Celsius.

Complications: hypoxic brain injury, acute respiratory distress syndrome, aspiration pneumonia (including Aeromonas, Pseudomonas and fungi), arrhythmia, acute kidney injury and disseminated intravascular coagulation.

• Spectrum from no symptoms, to cough, dyspnea and wheeze, to frothy pink sputum, hypoxemia, cyanosis, altered consciousness and apnea
• Vomiting of swallowed water, hypothermia and abdominal distension
• Associated injury: cervical spine and head trauma after diving, and intoxication
• Delayed pulmonary edema over 4 to 6 hours after a symptom-free interval
• Red flags: apnea, Glasgow coma score under 13, saturation under 94%, abnormal chest radiograph, submersion for over 5 minutes and any cardiac arrest

1. Immediate assessment: airway, breathing, circulation, saturation, temperature and glucose.
2. Chest radiograph at presentation and again after 6 hours: bilateral infiltrates and pulmonary edema.
3. Arterial blood gas, electrolytes, creatinine, creatine kinase, lactate and full blood count.
4. ECG, and a family history with genetic testing when drowning was unexplained.
5. CT head and cervical spine when diving, trauma or unknown mechanism, or when consciousness is reduced.
6. Blood alcohol and toxicology screen, and sputum and blood cultures when pneumonia is suspected.

Differentials: cardiac arrhythmia as the primary event, seizure, intoxication, head injury, hypothermia and diving injury.

1. Rescue and resuscitation: begin ventilation as soon as possible (in the water if trained). For apnea or arrest give 5 initial rescue breaths with oxygen, then 30 chest compressions to 2 breaths, since the arrest is hypoxic. Do not try to drain water from the lungs or use abdominal thrusts. Use an automated defibrillator after drying the chest.
2. Oxygen: 15 L/min by mask. For hypoxemia use continuous positive airway pressure 5 to 10 cmH2O or non-invasive ventilation.
3. Intubation for Glasgow coma score under 9, exhaustion, or refractory hypoxemia: lung-protective ventilation with tidal volume 6 mL/kg ideal body weight and positive end-expiratory pressure 8 to 15 cmH2O titrated to oxygenation, and a nasogastric tube.
4. Arrest drugs: epinephrine 1 mg IV every 3 to 5 minutes (children 0.01 mg/kg), standard shock-based care, and extracorporeal life support for refractory arrest in centres with it.
5. Hypothermia: remove wet clothing and rewarm to a normal temperature. Avoid hyperthermia afterward.
6. Circulation: IV crystalloid 10 to 20 mL/kg for hypotension, and norepinephrine 0.05 to 0.5 micrograms/kg/min IV for persistent shock.
7. Antibiotics only for infection or for submersion in grossly contaminated water: amoxicillin-clavulanate 1.2 g IV every 8 hours (children 30 mg/kg every 8 hours), or piperacillin-tazobactam 4.5 g IV every 6 hours for severe or sewage exposure. Do not give prophylactic steroids or antibiotics routinely.
8. Seizures: lorazepam 4 mg IV (children 0.1 mg/kg). Immobilize the cervical spine only if trauma or a diving mechanism is possible.
9. Refractory acute respiratory distress syndrome: prone positioning, neuromuscular blockade, and venovenous extracorporeal membrane oxygenation.
10. Post-arrest care: maintain a normal temperature (36 to 37.5 degrees Celsius), avoid fever, and control glucose and blood pressure.
11. Observation: at least 6 to 8 hours for those who were symptomatic, and discharge only if saturation is normal on air, examination is normal and the repeat chest radiograph is clear. Admit all with abnormalities, and ventilated patients to intensive care.

Prevention: constant supervision of children, pool fencing, swimming lessons, life jackets and avoidance of alcohol near water. Follow-up for neurological and cognitive assessment at 3 months after hypoxic injury.