A 14 month old male infant presents to the emergency department via ambulance in full arrest. His mother left him playing in the living room. After 30 minutes, she was not able to find him inside the house. He was found at the bottom of the swimming pool. The screen door which leads to the pool was found to be open. Initially, he was cold, blue and limp. She started CPR after calling 911. The EMS team performs CPR and resuscitation en route to the hospital. The infant is intubated and epinephrine is administered via the tracheal tube. An intraosseous (IO) line is started and epinephrine is given IO as well. After 35 minutes of resuscitation efforts in the emergency department, the infant is pronounced dead.
Submersion injuries, which include drowning and near-drowning continue to be one of the leading causes of deaths in children, after motor vehicle accidents and cancer. In the United States, approximately 5000 children and adolescents die every year as a result of submersion injuries (1,2). Submersion injuries have a bimodal age distribution. The first peak is seen in infants and toddlers less than 4 years of age, who are susceptible to submersion in swimming pools, baths or household buckets (2). Lack of caregiver supervision, neglect, and suboptimal barriers are contributing factors. The second peak occurs in adolescents and is associated with risk-taking behaviors as well as alcohol and drug use. Coexisting trauma and suicide intent should always be considered in this older age group (3).
Drowning is defined as death within the first 24 hours of submersion, which includes death at the scene. Near-drowning is defined as submersion in which survival is greater than 24 hours, regardless of morbidity and mortality. The common pathophysiologic events in all drowning incidents are asphyxia and hypoxia. After a submersion incident, most victims will go through a period of struggle and breath-holding, or water will enter the oropharynx and larynx resulting in choking and laryngospasm (4,5). This will lead to hypoxia and loss of consciousness, followed by asphyxia and death. Loss of protective reflexes will occur in most victims, leading to water aspiration. This is known as "wet drowning." In 10% to 20% of victims, intense laryngospasm persists and no significant amount of water enters the lungs, even though the victim is unconscious (4,5). This is also known as "dry drowning." A great deal of controversy existed in the past regarding the pathophysiology of drowning and near-drowning. Sufficient research data has shown that there are no significant physiologic differences between salt water and freshwater submersions or wet and dry drowning. Salt water submersion victims will likely be hypernatremic and fresh water submersion victims will likely be hyponatremic, but this difference does not appear to be clinically important in most instances, and is largely due to swallowed water rather than aspirated water.
All organ systems are affected after a submersion injury as a result of asphyxia, hypoxia and acidosis. Respiratory failure, aspiration pneumonia, barotrauma, and adult respiratory distress syndrome (ARDS) are frequent complications. Arrhythmias as well as cardiogenic shock may also be seen. Renal dysfunction is a common finding (acute tubular necrosis). Liver and gastrointestinal dysfunction may also occur. However, it is the irreversible hypoxic-ischemic damage to the brain that accounts for most of the long term complications (2,6). Risk factors that have been identified as indicators of irreversible neurologic injury and mortality include (2,6):
. . . . . 1) Age less than 3 years.
. . . . . 2) Submersion longer than 5 minutes.
. . . . . 3) Resuscitation not attempted for 10 minutes after rescue.
. . . . . 4) Seizures, fixed/dilated pupils, decerebrate posture, flaccid extremities and/or coma.
. . . . . 5) Asystole on arrival to the emergency department.
. . . . . 6) Arterial blood pH <7.1.
. . . . . 7) Elevated blood sugar level.
. . . . . 8) Glasgow Coma Scale <5.
. . . . . 9) Apnea after cardiopulmonary resuscitation.
A classification of submersion victims based on neurologic function was developed by Conn and Baker (7,8). This classification has several advantages: 1) It estimates the magnitude of hypoxic insult. 2) It guides the selection of appropriate therapy. 3) It is highly predictive of outcome. The classification is as follows:
Category A: Awake, alert, fully conscious, minimal injury.
Category B: Blunted, obtunded to stuporous, normal central respiratory drive, purposeful responses to pain.
Category C: Comatose. Unarousable, abnormal central respiratory pattern, abnormal motor responses to painful stimuli, seizures may occur. Category C is further divided into subcategories based on worsening CNS function: C1) Decorticate, Cheyne-Stokes respirations. C2) Decerebrate, central hyperventilation. C3) Flaccid, apneustic or cluster breathing. Manifestations of multiorgan dysfunction failure appear in category C (7,8).
The management of the drowning victim starts in the field with bystander cardiopulmonary resuscitation (CPR) after activation of the Emergency Medical System (EMS). The goal is to improve oxygenation and ventilation as rapidly as possible to minimize cerebral hypoxic-ischemic damage. The neck should be immobilized if there is a suspicion of spinal cord injury (e.g., intoxicated adolescent). Patients should be kept warm and dry. Hypotension should be treated aggressively. All patients should be transported quickly to the emergency department for further evaluation and treatment. Initially, vital signs and core temperature are obtained, followed by respiratory, cardiovascular and neurologic evaluation. Traumatic injuries should be excluded. Initial laboratory tests include: arterial blood gas (ABG), chest radiograph, electrolytes and serum glucose. Optional tests to be considered include: CBC, renal function tests, liver function tests and urinalysis. Even the ABG is optional in many instances since oxygenation can be measured via pulse oximetry and metabolic acid-base status can be determined from the serum bicarbonate. Most patients with a significant submersion injury should be admitted to the hospital for observation; however category A patients, with no other significant injuries, may be discharged from the emergency department after a period of observation.
Although the survival rate has improved with advances in emergency care, prevention is the best strategy. Parental supervision of infants and children while in and around water is essential. Early swimming lessons have not been shown to reduce the incidence of drowning. The policy statement published in 2000 by the American Academy of Pediatrics entitled, "Swimming Programs for Infants and Toddlers" does not endorse swimming instructions for infants and children until after their fourth birthday (9). Moreover, children and adolescents prone to conditions such as syncope and seizures should always have a partner. So far, the only environmental preventive strategy that has decreased the number of submersion injuries in children is the installation of four-sided fencing that isolates the pool from the house (i.e., the house itself should not open directly into the pool area). Finally, all parents should be trained in cardiopulmonary resuscitation (CPR), since rapid institution of effective oxygenation and ventilation after a submersion injury has been associated with improved outcomes.
1. All of the following are considered risk factors for drowning except:
. . . . . a. Head trauma
. . . . . b. Alcohol use
. . . . . c. Upper respiratory infection with wheezing
. . . . . d. Seizure disorder
. . . . . e. Illegal drug use
2. True/False: The American Academy of Pediatrics advocates swimming classes for all children over two years of age.
3. Which of the following factors is associated with a poor outcome in a drowning case?
. . . . . a. Low blood sugar level
. . . . . b. Submersion longer than 5 minutes
. . . . . c. Drug or alcohol use
. . . . . d. Return of spontaneous cardiac rhythm following CPR
. . . . . e. CPR for less than 3 minutes
4. Which of the following interventions will improve the outcome in a drowning victim?
. . . . . a. Early intubation
. . . . . b. Transfer to a trauma center
. . . . . c. Intravenous access
. . . . . d. Early bystander CPR
. . . . . e. Cervical spine precautions
5. All of the following are complications after a submersion injury except?
. . . . . a. Adult respiratory distress syndrome (ARDS)
. . . . . b. Arrhythmias
. . . . . c. Renal dysfunction
. . . . . d. Hypernatremia
. . . . . e. Aspiration pneumonia
Morisada MM. Near Drowning. In: Yamamoto LG, Inaba AS, DiMauro R (eds). Radiology Cases In Pediatric Emergency Medicine, 1996, volume 5, case 15. Available online at: www.hawaii.edu/medicine/pediatrics/pemxray/v5c15.html
1. American Academy of Pediatrics, Committee on Injury and Poison Prevention. Drowning in infants, children, and adolescents. Pediatrics 1993;92:292-294.
2. Kallas HJ, O'Rourke PP. Drowning and Immersion Injuries in Children. Cur Opin Pediatr 1993;5:295-302.
3. Smith GS, Brenner RA. The Changing Risks of Drowning for Adolescents in the U.S. and Effective Control Strategies. Adolesc Med 1995;6(2):153-170.
4. Levine DL, Morriss FC, Toro LO, Brink LW, Turner GR. Drowning and Near-Drowning. Pediatr Clin North Am 1993;40(2):321-336.
5. Zuckerman GB, Conway EE. Drowning and Near Drowning: A Pediatric Epidemic. Pediatr Ann 2000;29(6):360-366.
6. Habib DM, Tecklenburg FW, Webb SA, et al. Prediction of childhood drowning and near-drowning morbidity and mortality. Pediatr Emerg Care 1996;12:255-258.
7. Conn AW, Montes JE, Baker GA. Cerebral Salvage in Near-Drowning Following Neurologic Classification by Triage. Can Anesth Soc J 1980;27:201.
8. McCloskey K, Aoki BY. Evaluation, Stabilization, and Transport of the Critically Ill Child. 1997, Year Book Medical Publishers.
9. American Academy of Pediatrics, Committee on Injury and Poison Prevention. Swimming program for infants and toddlers. Pediatrics 2000;105:868-870.
10. Yamamoto LG, Yee AB, Matthews WJ, Wiebe RA. A One Year Series of Pediatric Emergency Department Water-Related Injuries: The Hawaii EMS-C Project. Pediatr Emerg Care 1992;8:129-133
Answers to questions
2. False. The AAP recommends against swimming lessons below the age of 4 years.
5. d. Hypernatremia may occur in a salt water submersion victim, but it is not considered clinically important in most instances and it is not considered to be a "complication".