Chapter 124: Near Drowning

INTRODUCTION

Drowning is submersion in a liquid resulting in respiratory distress or failure. 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 morbidity and mortality.

CLINICAL FEATURES

Up to 20% of patients who suffer submersion injuries do not aspirate water, but sustain injury due to asphyxia. 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.

DIAGNOSIS AND DIFFERENTIAL

Evaluate patients for associated injuries (e.g., traumatic injuries to the brain or 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 chest radiograph (CXR) is usually obtained but is frequently normal in patients who are otherwise asymptomatic. Without a history of diving or associated trauma, routine cervical immobilization and computerized tomography (CT) of the brain are not necessary.

EMERGENCY DEPARTMENT CARE AND DISPOSITION

1. Treatment for submersion events is summarized in Figure 124-1.

2. Measure core temperature. Treat hypothermia if present. (See Chapter 118, “Frostbite and Hypothermia.”) Hypothermic victims of cold-water submersion with cardiac arrest should undergo prolonged and aggressive resuscitation maneuvers until they are normothermic or considered not viable.

3. Data do not support routine antibiotic prophylaxis for pulmonary aspiration.

4. 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.

5. Patients who arrive in the emergency department in asystole or cardiac arrest after warm water submersion and are normothermic have a poor prognosis for recovery without significant neurologic handicaps.

FURTHER READING