Drowning Incidents

Written By: Corey Heitz
Boonshoft School of Medicine
Wright State University, Dayton, Ohio

Edited By: Lorraine Thibodeau
Albany Medical Center, Albany, New York

Drowning Incidents Objectives

Upon completion of this self-study module, you should be able to:

  • Define drowning and classify drowning incidents by outcome.
  • Stabilize and perform an initial evaluation of a patient after a drowning incident.
  • Appropriately test for and treat complications of drowning incidents.
  • Differentiate between primary and secondary drowning (evaluate for causes of secondary drowning).
  • Appropriately disposition a patient after a drowning incident.

In 2005, the World Health Organization made recommendations concerning the definition of submersion and immersion incidents. Drowning should be "the process of experiencing respiratory impairment from submersion/immersion in liquid." The term "near-drowning" should be abandoned, instead a description of the outcome of the drowning incident should be used (death, morbidity, no morbidity). In recent practice, drowning refers to death within 24 hours from submersion or immersion in liquid, while near-drowning refers to survival past 24 hours.

Drowning incidents are not uncommon. In 2006, 4,279 deaths were reported from drowning, with 5,163 nonfatal incidents. Nonfatal incidents may be underestimated due to underreporting. The majority of deaths are children, with peak ages of 1-4, and shows a seasonal variability. Drowning incidents most often occur in freshwater, with bathtubs and swimming pools being high on the list of locations. Predictably, saltwater drownings occur near coastlines.

Clinical Presentation

Drowning incidents will show a wide variation in how they present. Patients may be found at the bottom of a pool after a period of time not being seen, or in addition they may be found floating in a lake, pool or other body of water. Small children have been found face down in a bathtub, as well as toilets and 5-gallon buckets. The length of time of immersion or submersion is also variable, and quite possibly will be unknown.

Symptoms can range from the relatively asymptomatic patient to one with severe impairment. Respiratory complications and their manifestations include hypoxia, tachypnea, and abnormal lung sounds. Patients may develop cardiac dysrhythmias if hypoxic or hypothermic. Ingestion of water can lead to vomiting, and therefore aspiration must be considered. If the submersion time was lengthy, a patient is likely to be hypothermic. Neurologic complications can range from no alterations, to mildly altered mental status, to obtundation. It is important to evaluate motor and sensory function, as neurologic trauma may have occurred.

Initial Actions

Upon initial contact with the patient, it is imperative to evaluate the ABCs (airway, breathing, and circulation.) A full set of vital signs should be obtained, including pulse oximetry and rectal temperature. Any life-threatening abnormalities should be corrected prior to proceeding. Interventions may include high flow oxygen, as well as active airway management (endotracheal tube placement) not only to correct refractory hypoxemia, but in cases of severely altered mental status, to protect the airway from aspiration of gastric contents. Along with evaluation and management of the airway, circulatory status should be addressed. IV access will need to be established, with large bore IVs, intraosseus (IO), or central venous catheters, and high-volume fluid resuscitation may need to be initiated. Pulseless patients should have CPR initiated immediately. A delay in basic life support measures of 10 minutes, or 25 minutes of pulselessness, are both independent predictors of a poor prognosis. Rewarming measures may be needed for the hypothermic patient. If there is a concern for cervical spine injury, the patient should be placed in a cervical collar for immobilization. This decision will be made based on the history. Events that were unwitnessed, occurred during a diving injury, a fall, or a motor vehicle accident should result in the placement of a cervical collar. In one study, there was a 0.5% incidence of cervical injuries in patients who underwent drowning incidents; all of the injured patients exhibited a mechanism putting them at risk.

Once the initial steps of stabilization have been performed, continue the evaluation. A history of the events must be obtained, from the patient, witnesses, or emergency medical personnel who responded to the scene.

Important pieces of information include the details of what happened to the patient (how did they come to be submerged in the water), what was the duration of the submersion, and what occurred after they were removed from the water. Were the patient's breathing and pulse evaluated immediately? Were any resuscitative measures undertaken, such as CPR, rescue breaths, or removal of foreign bodies from the airway? Was the patient alert after being removed from the water, and if not, what was their level of alteration, and what changes occurred during transport to the hospital? What treatment was given prior to arrival at the hospital? Other pertinent facts may include the patient's medical history, medications, recent ingestion of drugs or alcohol, and history of suicidal ideation or suicide attempts in the past.

After the history is taken, a thorough but focused physical exam must be performed. Areas on which to focus include signs of external trauma, especially including the head and neck, lung sounds to evaluate for aspiration of water, skin color looking for evidence of cyanosis, and a rectal (core) body temperature. If the patient will cooperate, a neurologic exam should be performed.

Diagnostic Testing

Diagnostic testing in the case of a drowning incident should be based on the severity of the injury. All patients should initially be placed on cardiac monitoring with pulse oximetry, and symptomatic patients should have an electrocardiogram (EKG) to evaluate for arrhythmias. Anyone who has impairment of respiratory function or any concern for aspiration should undergo chest radiography. An evaluation of blood electrolytes may be performed. Historically, it has been proposed that severe fluid volume and electrolyte changes could be seen based on the amount of fresh or saltwater ingested or aspirated. Freshwater ingestions would lead to hypervolemia from the hypotonicity of the fluid, while saltwater would lead to hypovolemia and resultant hypernatremia. However, animal studies show that while the observed changes in volume status, electrolytes, and hemoglobin following aspiration or ingestion of fluid do occur,3 the amount ingested must be greater than 11cc/kg, and victims typically aspirate less than 4cc/kg.6 More likely, it is hypoxia and metabolic acidosis that results in morbidity and mortality. In the patient with severe or persistent hypoxia, or altered mental status, arterial blood gases may assist in the evaluation.

The chest x-ray above demonstrates a pneumonitis developing soon after submersion injury.

Secondary drowning is a drowning incident that occurs due to another cause. Causes of secondary drowning may include ingestion of drugs or alcohol (with or without intent for self-harm), myocardial infarction, syncope, cerebrovascular accident, and trauma such as mentioned above during a motor vehicle accident or a diving injury. Pursue causes of secondary drowning in cases where the events are unclear, or when the history or physical exam give you suspicion that something may have occurred prior to the drowning incident.

Treatment

Emergency department treatment will mostly consist of stabilization and supportive care, with protection of the airway, the correction of hypoxia, and minimization or prevention of complications from traumatic injuries sustained at the time of the incident. Treatment modalities may include placement of an advanced airway for severely altered mental status or hypoxia resistant to high-flow oxygen, management of cardiac dysrhythmias, volume resuscitation, and active rewarming in cases of hypothermia.

When water enters the alveoli, it causes a loss of surfactant. Alveolar collapse occurs, with resultant hypoxia. Once intubated, ventilator settings similar to those used in acute respiratory distress syndrome (ARDS) may be needed. This includes positive end-expiratory pressure (PEEP), as well as the use of alveolar recruitment maneuvers. Suctioning may be indicated in large-volume aspiration. Empiric antibiotics are not recommended,7 but in cases where infection develops, broad-spectrum antibiotics should be used.8 Steroids, while once thought to be helpful, have not been shown to be beneficial to treat or prevent pneumonia.8 If the drowning occurred during scuba diving, hyperbaric oxygen may be indicated, but only after initial resuscitative efforts have been performed.9 While theorized, no clinical evidence currently exists supporting the use of hyperbaric chambers for drowning in the absence of decompression illness.

The most common dysrhythmia exhibited after a drowning incident is bradycardia, likely due to prolonged hypothermia. Cardiac manifestations should be managed as recommended by ACLS protocols. Hypotension may occur due to peripheral vasoconstriction to keep core temperature elevated, as well as from cardiac suppression from hypothermia.7

Disposition

Prognosis and disposition of the patient will be largely determined by their clinical status.

Any intubated patient, those with persistent alterations of mental status, large oxygen requirements, or those who are hypothermic should be admitted to intensive care. Patients who exhibit respiratory symptoms or changes on chest radiography should be admitted to a monitored bed, and have repeat exams and radiographs performed until they normalize. A patient who has normal oxygen saturations, no respiratory symptoms, and has a normal mental status may be safely discharged after a period of observation of at least 6 hours.10

It is also necessary to consider the circumstances surrounding the incident. If suspicion of child abuse exists, or if the drowning occurred due to self-harm or suicidal intent, then the patient may require admission from a standpoint other than a medical one.

Pearls & Pitfalls

References

  1. van Beeck EF, Branche CM, Szpilman D, Modell JH, Bierens JJ. A new definition of drowning: towards documentation and prevention of a global public health problem. Bull World Health Organ. Nov 2005;83(11):853-856.
  2. Web-based injury statistics query and reporting system [database]. 2006. Accessed December 21, 2009.
  3. Salomez F, Vincent JL. Drowning: a review of epidemiology, pathophysiology, treatment and prevention. Resuscitation. Dec 2004;63(3):261-268.
  4. Papa L, Hoelle R, Idris A. Systematic review of definitions for drowning incidents. Resuscitation. Jun 2005;65(3):255-264.
  5. Watson RS, Cummings P, Quan L, Bratton S, Weiss NS. Cervical spine injuries among submersion victims. J Trauma. Oct 2001;51(4):658-662.
  6. Modell JH, Davis JH. Electrolyte changes in human drowning victims. Anesthesiology. Apr 1969;30(4):414-420.
  7. Wagner C. Pediatric submersion injuries. Air Med J. May-Jun 2009;28(3):116-119.
  8. van Berkel M, Bierens JJ, Lie RL, et al. Pulmonary oedema, pneumonia and mortality in submersion victims; a retrospective study in 125 patients. Intensive Care Med. Feb 1996;22(2):101-107.
  9. Moon RE, Long RJ. Drowning and near-drowning. Emerg Med (Fremantle). Dec 2002;14(4):377-386.
  10. Causey AL, Tilelli JA, Swanson ME. Predicting discharge in uncomplicated near-drowning. Am J Emerg Med. Jan 2000;18(1):9-11.