Rapid resuscitation of a drowning victim (quickly restoring ventilation and oxygenation) optimizes outcome. After safe removal of the victim from the water, CPR should be initiated as quickly as possible. Trauma as a cause of drowning is uncommon, and most injured drowning patients have a history of trauma or signs of injury on examination.10 Cervical spine injury is rare (0.5%) in drowning unless there is a history of diving, falling from a significant height, or motorized vehicle crash.11 Use cervical spine precautions if the history warrants it.
Administer high-flow oxygen by facemask if the patient is breathing or by positive-pressure bag-valve mask ventilation if the patient is not breathing. For patients who do not recover spontaneous respiratory effort, endotracheal intubation and positive-pressure ventilation are necessary.
All patients with drowning amnesia for the event, loss of or depressed consciousness, or an observed period of apnea, as well as those who require a period of artificial ventilation, should be transported to an ED for evaluation, even if they are asymptomatic at the scene. The patient should be warmed and monitored, and IV access should be established (Figure 215-1).
Drowning event algorithm. CBC = complete blood count; CK = creatine kinase; CPAP = continuous positive airway pressure; CVP = central venous pressure; CXR = chest radiograph; GCS = Glasgow Coma Scale score; ICU = intensive care unit; PEEP = positive end-expiratory pressure; PT = prothrombin time; PTT = partial thromboplastin time; SaO2 = oxygen saturation (via pulse oximetry); U/A = urinalysis.
Upon the patient's arrival at the ED, assess and secure the airway, provide oxygen, determine core temperature, and assist ventilation as necessary. If the patient is hypothermic, administer warmed isotonic IV fluids and apply warming adjuncts (e.g., blankets, overhead warmers, warming devices). Address any associated injuries. Because cervical injury is rare without a history of diving or associated trauma, routine cervical immobilization and CT of the brain are not necessary.11
Patients who present to the ED with a Glasgow Coma Scale score of >13 and an oxygen saturation of ≥95% are at low risk for complications (Figure 215-1) and should be observed for 4 to 6 hours. If the pulmonary examination does not reveal rales, rhonchi, wheezing, or retractions and arterial oxygen saturation on room air remains ≥95%, the patient can be safely discharged home. Laboratory studies and radiographs are unnecessary and are not predictive of discharge.12 The patient should be told to return if fever, mental status changes, or pulmonary symptoms occur. If, after 4 to 6 hours, the patient develops an oxygen requirement, the findings on pulmonary examination are abnormal (rales, rhonchi, wheeze, retractions, etc.), or the patient's condition deteriorates, reassessment and admission or transfer to a monitored bed are needed.
Patients who present to the ED with a Glasgow Coma Scale score of <13 should be maintained on supplemental oxygen and ventilatory support as needed. If high-flow oxygen (fraction of inspired oxygen of 40% to 60%) cannot maintain an adequate partial pressure of arterial oxygen (>60 mm Hg in adults, >80 mm Hg in children), then intubate the patient and provide positive-pressure ventilation. Chest radiography and laboratory studies should be done to evaluate for pulmonary aspiration and other complications (Figure 215-1). Although aspiration is common, prophylactic antibiotics have not been shown to improve outcome and may be associated with resistant infections.13 Continuous cardiac monitoring, pulse oximetry, temperature monitoring, and frequent reassessments should be performed for all patients. Hypothermia is a concern in patients who have been submerged in cold water (see chapter 209, Hypothermia).
If the patient is normothermic upon arrival in the ED and in cardiopulmonary arrest or asystole, serious thought should be given to discontinuing resuscitation efforts because recovery without profound neurologic complications is rare.14,15
Hospital management of drowning victims is largely supportive.16 All drowning victims who require ED resuscitation should be admitted to an intensive care unit for continuous cardiopulmonary and frequent neurologic monitoring. Most victims of significant submersion injury benefit from mechanical ventilation. Supernormal levels of positive end-expiratory pressure may be used to recruit fluid-filled lung units and aid oxygenation. Most patients demonstrate rapid improvement in oxygenation in the first 24 hours. Patients presenting with a significant aspiration pattern or cardiovascular collapse are predisposed to develop acute respiratory distress syndrome. Although prophylactic antibiotics lack supporting evidence, delayed pulmonary infection, particularly among patients requiring mechanical ventilation, is a risk, and unusual organisms, including Aeromonas species, should be considered if treatment is initiated. Care should be taken to avoid lung overdistention and ventilator-associated barotrauma.
For patients who have been resuscitated from cardiac arrest, the hemodynamic response to exogenously administered epinephrine is frequently short-lived, and most require a continuous infusion of dopamine or epinephrine in the ED or intensive care unit. Invasive (pulmonary artery catheter) or noninvasive (echocardiogram) measurement of ventricular function is often instructive. Hemodynamic recovery, when it occurs, can be expected within 48 hours. Patients demonstrating no hemodynamic recovery after 48 hours may slowly improve over the first week but are more likely to have long-term neurologic damage.17
Results of "brain resuscitation" after significant warm water drowning have been disappointing.9,16 The degree of cerebral edema is largely determined by the duration of the anoxic or ischemic insult at the time of submersion. Efforts to control cerebral edema, including the use of mannitol, loop diuretics, hypertonic saline, fluid restriction, and mechanical hyperventilation, have not shown benefit.16 Controlled hypothermia, barbiturate "coma," and intracranial pressure monitoring do not improve outcome in pediatric drowning victims.9 Although rare, complete or near-complete neurologic recovery after asystole has been reported in both children and adults after icy water submersion episodes.