Written by: Michael Conrardy , MD (NUEM PGY-2) Edited by: Gabby Ahlzadeh, MD (NUEM ‘19) Expert commentary by: Kristina McAteer, MD
Introduction
If you are an emergency physician, you likely will see submersion injuries often throughout your career. In the United States, from 2005-2014, there are approximately ten deaths per day from unintentional drowning, and about 3,536 annually. This number increases to eleven per day if you include boating-related deaths. One in five deaths involve children under the age of fourteen, and drowning is the second leading cause of death for children ages 1-14 [1,2]. Approximately 80% of all victims are male [2], and when considering adolescents and adults, alcohol is involved in up to 70% of cases [3]. Statistics for nonfatal drowning events are difficult to obtain, but studies estimate that they may occur several hundred times more frequently than reported deaths [4,5].
Example Case
While working in the emergency department on Friday night, three college students are brought in by EMS after “drinking alcohol and jumping in Lake Michigan.” Patient #1 received CPR for ten minutes en route, has a temperature of 32 degrees Celsius, signs of head trauma, and a cervical collar in place. Patient #2 experienced a short period of submersion and is in mild respiratory distress. Patient #3 was submerged for only a brief period of time and is completely asymptomatic.
Emergency Department Management of Submersion Injuries
Patient #1 - Severely Symptomatic Patients
Initial Management:
In serious cases of drowning, top concerns are hypoxemia, hypothermia, subsequent cardiac arrest, and other signs of trauma.
If in cardiac arrest, start ACLS and consider underlying causes such as hypoxemia or hypothermia
Remove wet clothing and use rewarming techniques
Chest x-ray, blood gas, labs, end tidal CO2. Initial CXR is often normal but can be helpful in tracking the patient’s condition.
Assess for signs of trauma and obtain appropriate imaging. It is important to note that cervical spine injuries are uncommon (<5%) in cases of drowning, and cervical collars should not distract from airway management [6].
Management of airway, ventilation, oxygenation:
Fluid aspiration can lead to loss of surfactant, pulmonary edema, and hypoxemia from V/Q mismatch. Hypoxemia is the primary cause of end-organ damage in submersion injuries (typically cardiac and neurologic) and treating it should be your top priority. Here are some general guidelines:
Airway: Intubate patients if unable to protect airway, O2Sat < 90% despite supplemental O2, or PaCO2 >50
Ventilation: Positive pressure opens alveoli and improves ventilation in drowning.
Unable to protect airway: Start with bag-valve-mask and then intubate. Use ARDS settings of Vt 6-8 mL/kg, Pplateau < 30mmHg, and increased PEEP.
Able to protect airway: Use non-invasive positive pressure ventilation in alert, symptomatic patients for goal O2Sat > 94% [6].
Oxygenation: Use maximum available supplemental O2 initially and wean as tolerated.
Medications:
No medications need to be routinely used for submersion injuries. Bronchospasm can occur, and if suspected should be treated with inhaled beta-adrenergic agonists. Glucocorticoids have not been shown to be helpful in preventing subsequent lung injury and may interfere with healing, and not enough data exists to support routine administration of exogenous surfactant. Antibiotics should only be used in cases where signs of infection develop or if the patient was submerged in grossly contaminated water [7].
ECMO:
Data on use of ECMO to treat patients with severe pulmonary edema or signs of ARDS are extremely limited, although initial results are encouraging [9]. This is an area of ongoing research, and perhaps we may eventually see early initiation of ECMO as standard practice for severely symptomatic patients.
Patient #2 - Mildly Symptomatic Patients
The main takeaway from patient #2 is that all patients who are symptomatic on arrival to the ED (requiring ventilatory assistance or supplemental O2) should be admitted to the hospital. Airway, ventilation, and oxygenation should be managed as above, and serial chest x-rays can help monitor for development of pulmonary edema in symptomatic patients [6].
Patient #3 - Asymptomatic Patients
Although most research on safe discharge has been in children, it is generally accepted that asymptomatic patients can be safely discharged after 4-6 hours of monitoring. Patients should have normal pulmonary exam, SaO2>95% on room air, and GCS>13 [6,10]. Some clinicians advocate for observing up to eight hours based on a study that observed one pediatric patient who did not develop symptoms until seven hours post-submersion [11], although six hours in the ED with return precautions is probably adequate in most cases. Many clinicians obtain basic labs on all patients and a chest x-ray prior to discharge to confirm that there are no signs of pulmonary edema, although no strong evidence supports these practices.
Key Takeaways:
Hypoxemia is the main cause of harm, prioritize the airway and use positive pressure
Initial chest radiographs are often normal, but can be used to track a patient’s clinical status
Blood gas is the most useful laboratory test in symptomatic patients, additional testing (e.g. ECG, CBC, chem, troponin) is particularly useful in patients with altered mental status
Asymptomatic patients may be safely discharged after six hours of monitoring
Expert Commentary
The terminology can be confusing with such terms as drowning, nonfatal drowning, submersion injury, dry drowning, wet nonfatal drowning, and so on. Most recently (2010) the AHA recommended a more straightforward approach and supported the Utstein definition which hopefully offers some clarification, relieves some of the angst when approaching this population, and standardizes research and reporting. The Utstein defines a drowning as “a process resulting in a primary impairment from submersion or immersion in a liquid medium.” [1]
The key is to keep it simple. Is your patient symptomatic from the exposure? If so, focus on the ABC’s and get to work!
You will often see pediatric patients as drowning victims. Drowning is a leading cause of accidental death in children under 5 years of age, particularly in states where swimming pools or beaches are more accessible. The states of California, Arizona and Florida lead the way [2]. The second peak is in older ages (15-25 yo), primarily males, and involves more rivers, lakes and beaches. [3]. The distinction between fresh and salt water drownings is no longer considered important as the volume of aspirated water is so small that the theorized electrolyte shifts do not have any real physiological impact [4]. Both wash out pulmonary surfactant.
As appropriately pointed out it is often is not the drowning that causes mortality. It is therefore necessary to consider concomitant trauma, toxic ingestions (at the very least alcohol leading to impaired judgment!), and hypothermia. Hypoxemia and the resultant hypoxia is ultimately the cause for death, often impacting multiple organ systems, and thus it is your job to reverse the hypoxemia as quickly as possible! Supplemental oxygen, BIPAP (Bilevel positive airway pressure), endotracheal intubation and if necessary, ECMO (extracorporeal membrane oxygenation) are management options. There is a neuroprotective effect of hypothermia and in some cases patients make a complete recovery despite a prolonged resuscitation. Age > 14, duration of submersion > 5 minutes, time to basic life support > 10 minutes, resuscitation duration > 25 minutes, GCS (Glascow coma scale) <5, persistent apnea and requirement of CPR in the emergency department and arterial blood pH <7.1 have all been associated with a poor prognosis. [5]
Vanden Hoek TJ, Morrison LJ, Shuster M, et al. Part 12: Cardiac Arrest in special situations 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergent Cardiovascular Care. Circulation 2010; 122: S829.
Brenner Ra. Prevention of drowning in infants, children, and adolescents. Pediatrics 2003; 112:440.
DeNivola, LK, Falk, JL, Swanson ME, et al. Submersion injuries in children and adults. Crit Care Clin 1997;12:477.
Orlowski JP, Szpilman D. Drowning, Resucue, resuscitation and reanimation. Pediatr Clin. North Am 2001. 48:627.
Quan L, Mack CD, Schiff MA. Association of water temperature and submersion duration and drowning outcome. Resuscitation 2014.85:790.
Kristina McAteer, MD
Assistant Professor of Emergency Medicine
Brown University
How To Cite This Post
[Peer-Reviewed, Web Publication] Conrardy M, Ahlzadeh G. (2019, July 1). Sink or Swim: The management of submersion injuries. [NUEM Blog. Expert Commentary by McAteer Kristina]. Retrieved from http://www.nuemblog.com/blog/drowning.
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