Drowning

Stephanie Lareau, MD, FAWM,
Assistant Professor Emergency Medicine,
Virginia Tech- Carillon Clinic School of Medicine

Objectives

  • Define drowning and the terminology used to describe this condition.
  • Discuss risk factors for drowning.
  • Discuss management of drowning in both pre-hospital and hospital environments.

Introduction

Drowning is defined as “the process of experiencing respiratory impairment from submersion/immersion in a liquid” by the World Health Organization. Drowning begins with respiratory impairment due to submersion (victim’s airway under the surface of the water) or immersion (water splashes over the victim’s face). Although no longer recommended, the classifications of “near drowning” and “drowning” are still commonly used in literature and among laypersons. Near drowning refers to respiratory impairment from submersion/immersion without mortality. Drowning refers to mortality from water submersion/immersion. The preferred terms to use now are “drowning without morbidity,” “drowning with morbidity” and “drowning with death.”
In the United States, drowning is the tenth leading cause of injury death overall. It is the leading cause of unintentional injury death in children between age 1-4 years and the second leading cause in children ages 5- 14.

Drowning is most common among toddlers and teenage boys. It typically occurs in home swimming pools, bathtubs or buckets. Males are 4 times more likely to drown than females and black children have a 1.3 times higher rate of drowning than children in other ethnic groups.

Alcohol use is common among older drowning victims. Pre-existing conditions including seizures and pre-existing cardiac disease also increase risk of drowning. Trauma may coexist as a result of diving or falls.

Initial Actions and Primary Survey

The initial approach to a patient with suspected drowning is similar to the approach to any other critically ill patient. Initial efforts should focus on resuscitation, including evaluation and treatment of airway, breathing and circulation. Because respiratory arrest is the most common cause of cardiac arrest in drowning victims, the traditional A-B-C approach should be used for drowning victims instead of the AHA’s new C-A-B approach. Resuscitation with rescue breaths may begin in the water if responders are properly trained. Chest compressions should not be attempted in the water as they will not be effective.
Mechanism of injury should also be considered to determine whether spinal immobilization and further trauma evaluation is indicated. Drowning victims are at high risk for hypothermia and should be treated for hypothermia if indicated.

Presentation

The history from the patient, witnesses or EMS are vital in diagnosing drowning. When the event was not witnessed it is important to remember to evaluate for trauma and other medical conditions.
The clinical presentation varies from asymptomatic to benign conditions like a mild cough to more serious conditions including respiratory failure with cardiac arrest, depending on various factors: the reason for submersion, time of submersion, temperature of the water, and amount of water aspirated.

Healthy patients who have been rescued from drowning and have no respiratory symptoms, clear lungs and normal mental status may not need any further care. These patients should receive explicit directions about when to return as some respiratory symptoms may be delayed up to 24 hours.

Symptomatic patients can present with symptoms such as respiratory distress, tachypnea, hypoxia, coughing, or foaming from the mouth or nose. Auscultation of the lungs may reveal rhonchi or rales. Vomiting is also common. Hypothermia may be present. Traumatic injuries, especially from falls or diving may also be present.

Drowning begins when the patient’s airway is occluded by a liquid medium. When a person can no longer keep their airway clear of water, the typical response is to hold one’s breath. At some point the respiratory drive becomes too high and water is aspirated, causing coughing.

Laryngospasm can occur, but usually is overcome by brain hypoxia. Water aspiration continues until respiratory arrest occurs. Cardiac arrest ensues, typically after a period of tachycardia followed by bradycardia. The initial rhythm in the arrest is PEA followed by asystole.

About half of drowning resuscitations begin with bystander CPR. Patients requiring CPR will often present with CPR still in progress or in the peri-resuscitation stages. Drowning should be considered in any unconscious patient found submerged in water; however, it is critical to evaluate for trauma and medical conditions that could have led to drowning.

Diagnostic Testing

Diagnostic testing will vary based on the severity of illness. Vital signs and most importantly SpO2 should be obtained on all patients with suspected drowning. An ABG should be obtained in mechanically ventilated patients. Core temperature should be measured to assess for hypothermia.

Chest radiography should be obtained to evaluate for aspiration. Even in patients with mild symptoms, this can be important for use as a baseline. Cardiac monitoring and/or EKG should also be obtained. This is especially important if the patient may have had a medical etiology for drowning.

A trauma work up, especially c-spine imaging, should be obtained in any patient with a mechanism or exam concerning for trauma and in any obtunded patient for whom the cause of drowning is unknown. In the teenage and young adult population diving injuries commonly occur with drowning.

Treatment

Initial treatment should focus on correcting any airway and breathing difficulties with a goal of correcting hypoxemia and acidosis. Supplemental oxygen can be used for patients with mild symptoms. Patients with persistent hypoxia may require a trial of CPAP or even intubation. Patients with hypoxia and altered mental status will require endotracheal intubation. The treatment of pulmonary injury due to drowning is similar to the treatment of ARDS and applicable protocols should be utilized. Once a patient has been intubated, weaning should not occur for at least 24 hours as local pulmonary injury is unlikely to resolve in shorter timeframes.

Hypothermia is common in submersion patients. Depending on the degree of hypothermia, passive or active rewarming may be needed. Hypothermia has been shown to be neuroprotective in patients with prolonged time prior to ROSC.

There is no role for antibiotics in the initial treatment of drowning, but close monitoring for infection is indicated as bacterial pneumonia does occur from aspiration of water or vomit. This typically appears after 3-4 days, once pulmonary edema resolves. CNS infections have also been reported. In either situation, there is no evidence that empiric prophylactic treatment with antibiotics is efficacious. If pneumonia develops, antibiotic therapy can be tailored by using samples obtained from bronchial alveolar lavage.

The degree of hypoxia and amount of supplemental oxygen required will determine whether patients should be further observed in a general bed, telemetry bed or ICU.

The NEJM has created a useful algorithm for the treatment of persons who have drowned: http://www.nejm.org/action/showImage?doi=10.1056%2FNEJMra1013317&iid=f01

Pearls and Pitfalls

  • Always consider the mechanism of injury and evaluate for trauma.
  • Even on warm days, hypothermia is a real threat.
  • Remember to evaluate for underlying medical causes including seizures, dysrhythmias, or cardiac etiologies.
  • Respiratory symptoms may be delayed. If asymptomatic patients are discharged, ensure they have appropriate return precautions and the ability to access care.

References

  1. Cushing, T, Hawkins, S, et al. “Submersion Injuries and Drowning”. Wilderness Medicine. 2012; 1494-1513.
  2. David Szpilman, M.D., Joost J.L.M. Bierens, M.D., Ph.D., Anthony J. Handley, M.D., and
  3. James P. Orlowski, M.D. “Drowning” N Engl J Med 2012; 366:2102-2110
  4. http://www.nejm.org/doi/full/10.1056/NEJMra1013317#t=article
  5. van Beeck EF, Branche CM, Szpilman D, Modell JH, Bierens JJLM. A new definition of drowning: towards documentation and prevention of a global public health problem. Bull World Health Organ 2005;83:853-856
  6. http://cel.webofknowledge.com/InboundService.do?product=CEL&SID=4C74BbY13ULmjfJBrzI&UT=000233185100014&SrcApp=literatum&action=retrieve&Init=Yes&Func=Frame&SrcAuth=atyponcel&customersID=atyponcel&IsProductCode=Yes&mode=FullRecord
  7. Tipton MJ, Golden FS. A proposed decision-making guide for the search, rescue and resuscitation of submersion (head under) victims based on expert opinion. Resuscitation 2011;82:819-824 http://cel.webofknowledge.com/InboundService.do?product=CEL&SID=2Ewi5LfqojzJRaIqtZa&UT=000292763000007&SrcApp=literatum&action=retrieve&Init=Yes&Func=Frame&SrcAuth=atyponcel&customersID=atyponcel&IsProductCode=Yes&mode=FullRecord

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