Drowning
Mercedes M. Blackstone
INTRODUCTION
Terminology
Historically, the terminology used to describe drowning events has been somewhat confusing. The World Congress on Drowning has suggested that the term drowning be uniformly applied to describe any process in which there is respiratory impairment from submersion in a liquid medium, regardless of outcome. Inconsistent terms such as “near drowning,” “wet drowning,” and “dry drowning” should be abandoned. Similarly, there is no need to distinguish freshwater or saltwater drownings, because it makes little difference in the management of the patient. Water temperature at the time of drowning is significant because children who drown in very cold water (≤5°C) may have a better prognosis. Drowning usually results in either severe permanent brain damage or prompt complete recovery.
Epidemiology
Nationally, drowning is second only to motor vehicle accidents as the most common cause of death caused by nonintentional injury in children <19 years. For every drowning death, several children are hospitalized and countless others have submersion events with no morbidity. Males of all ages drown at higher rates than females. The highest rate of drowning is seen in children 1 to 4 years of age. In California, Arizona, and Florida, drowning is the leading cause of death in this age group. The vast majority of deaths in this age group occur in residential swimming pools. Infants are most likely to drown in bathtubs, and these drownings are sometimes the result of abuse or neglect. A second peak in drowning deaths occurs in the teen and young adult age groups in bodies of fresh water, with the highest rate in black males. These deaths are often associated with drug and alcohol use and other risk-taking behaviors.
Most drownings are preventable. Passage of legislation that requires proper pool fencing, limits alcohol access at public pools and beaches, and demands pool owners to be proficient in cardiopulmonary resuscitation (CPR) could significantly reduce morbidity and mortality rates. Preventive counseling for parents and swimming lessons for young children may also be helpful.
Pathophysiology
Drowning begins with a period of panic, during which the normal breathing pattern is lost and fluid enters the hypopharynx, triggering laryngospasm. The victim
then swallows large volumes of water, which is often aspirated into the lungs once the laryngospasm abates. This cascade results in poor surfactant function, increased capillary permeability, ventilation/perfusion mismatch, and poor lung compliance, all of which leads to acute respiratory distress syndrome (ARDS). The severe hypoxia that results from this pulmonary injury leads to multisystem organ failure, with cerebral hypoxia causing the majority of morbidity and mortality. Global anoxic-ischemic injury in turn causes cerebral edema and increased intracranial pressure. Hypothermia may protect the brain by causing a decrease in metabolic demand, but this is true only if the hypothermia occurred at the time of the drowning in extremely cold water.
then swallows large volumes of water, which is often aspirated into the lungs once the laryngospasm abates. This cascade results in poor surfactant function, increased capillary permeability, ventilation/perfusion mismatch, and poor lung compliance, all of which leads to acute respiratory distress syndrome (ARDS). The severe hypoxia that results from this pulmonary injury leads to multisystem organ failure, with cerebral hypoxia causing the majority of morbidity and mortality. Global anoxic-ischemic injury in turn causes cerebral edema and increased intracranial pressure. Hypothermia may protect the brain by causing a decrease in metabolic demand, but this is true only if the hypothermia occurred at the time of the drowning in extremely cold water.
APPROACH TO THE PATIENT
History
The age of the patient, duration of submersion, temperature of the water, presence of cyanosis or apnea at the scene, performance of CPR at the recovery scene, and amount of time that elapsed until CPR was initiated are all important historical points that influence prognosis and management (Table 29-1). One should also inquire about the possibility of a diving injury, alcohol use, or a past history of a seizure disorder or underlying cardiac dysrhythmia.
Physical Examination
During the physical examination, particular attention should be paid to assessment of vital signs (including the temperature) and to the neurologic and respiratory examinations. Frequent reassessment of the patient’s neurologic and respiratory status is an extremely important component of managing drowning victims.
TABLE 29-1 Prognostic Indicators of Poor Neurologic Outcome in Drowning Victimsa | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Pupillary response and the Glasgow coma score (GCS) (see Chapter 21, “Coma,” Table 21-4) should be assessed serially to determine the extent of anoxic-ischemic injury and the patient’s response to resuscitation attempts. The child who presents in asystole with fixed, dilated pupils and a GCS of <5 generally has a poor prognosis unless he responds fairly rapidly to resuscitation efforts or he has a core temperature of <32°C, following a very-cold-water drowning. In children with a GCS of >5 at presentation, the outcome is generally good. Unfortunately, neurologic damage as a result of drowning cannot be reversed. The gag reflex should be assessed to determine whether the child can protect his or her own airway. The cervical spine should be examined for any signs of injury, and if there is any history of diving, a cervical collar should be placed immediately.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
