Prognosis after submersion injuries depends on the degree of pulmonary and central nervous system injury and therefore is highly dependent on early rescue and resuscitation. Prevention is the most important means to reduce associated morbidly and mortality.
Up to 20% of patients who suffer submersion injuries do not aspirate water. Patients who aspirate water into their lungs have washout of surfactant, resulting in diminished alveolar gas transfer, atelectasis, ventilation perfusion mismatch, and hypoxia. Noncardiogenic pulmonary edema results from moderate to severe aspiration. Physical examination findings at presentation vary. Lungs may be clear or have rales, rhonchi, or wheezes. Mental status ranges from normal to comatose. Patients are at risk for hypothermia even in “warm water” submersions.
Evaluate patients for associated injuries (spinal cord) and underlying precipitating disorders including syncope, seizures, hypoglycemia, and acute myocardial infarction or dysrhythmias. Respiratory acidosis may be present early followed by metabolic acidosis later. Early electrolyte disturbances are unusual. A CXR is usually obtained but is frequently normal in patients who are otherwise asymptomatic.
Treatment for submersion events is summarized in Fig. 124-1.
Measure core temperature. Treat hypothermia if present. (See Chapter 118 “Frostbite and Hypothermia”)
Data do not support routine antibiotic prophylaxis for pulmonary aspiration.
Efforts at “brain resuscitation,” including the use of mannitol, loop diuretics, hypertonic saline, fluid restriction, mechanical hyperventilation, controlled hypothermia, barbiturate coma, and intracranial pressure monitoring, have not shown benefit.
Hypothermic victims of cold-water submersion with cardiac arrest should undergo prolonged and aggressive resuscitation maneuvers until they are normothermic or considered not viable.
Patients who arrive in the ED in asystole or cardiac arrest after warm water submersion and are normothermic have a poor prognosis for recovery without significant neurologic handicaps.
Submersion event algorithm.
For further reading in Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7th ed., see Chapter 209, “Near Drowning,” by Alan L. Causey and Mark A. Nichter.