Drowning

by Ana Spehonja

Case Presentation

A 6-year-old previously healthy male was brought to the emergency department (ED) after he fell into a freshwater lake while playing on the dock. Eyewitnesses found his body floating face down in the water. He was unaccounted for 10-15 minutes. They started basic life support right after they pulled him out of the water. He was cyanotic, apnoeic, pulseless with fixated and dilated pupils and tympanic temperature of 26,7 at arrival to ED. CPR was continued. After established airway and assessment for other injuries, they began to warm him up. ABG showed combined respiratory and metabolic acidosis with severe uncorrected hypoxemia. 15 minutes post mechanical ventilation and the return of a spontaneous heart rate with adequate blood pressure 110/67, SpO2 was 96%, pupils small and reactive to light and the tympanic temperature was 32,2°C. There was no spontaneous respiratory effort. ABG analysis showed uncompensated metabolic acidosis with corrected hypoxemia. He was stable enough for transfer to Paediatric ICU. After two days, ICU reported him to be stable with normal temperature.

Definition and Terminology

Previous Definitions

  • Drowning – submersion injuries that resulted in death in under 24 hours
  • Near drowning – those that survived over 24 hours.
  • Dry drowning – a state caused by laryngospasm, followed by convulsion, hypoxia that leads to loss of consciousness and death without entry of fluid to lungs. It accounts for 10-20% of submersion injuries.
  • Wet drowning – is a state caused by the aspiration of water. This leads to dilution and washout of the pulmonary surfactant. The result of this situation is diminished gas transfer across the alveoli, atelectasis, and ventilation-perfusion mismatch.

Currently, all submersion injuries are defined as drowning. In 2005 World Health Organisation published a new policy defining drowning as the ˝the process of experiencing respiratory impairment from submersion/immersion in liquid. Drowning outcomes are defined as death, morbidity, and no morbidity.˝

Drowning happens due to closed glottis, hypoxia, and cardiac arrest.
People don’t inhale water; it gets into the lungs later.

 

Immersion syndrome is syncope resulting from cardiac dysrhythmias on sudden contact with water that is at least 5C lower than body temperature. Vagal simulation leads to asystole and ventricular fibrillation secondary to QT prolongation after a massive release of catecholamines on contact with cold water. Loss of consciousness leads to secondary drowning. We can prevent this from happening with wetting our face and head before entrance into the water.

Drowning incidence is most common in toddlers and young children as they can drown in toilets, buckets, and bathtubs. The second are adolescents and young adults and third are the elderly.

The fluid medium in which a submersion happened has little clinical relevance, pulmonary injury and hypoxia are caused by the amount of water aspirated and the duration of submersion. In both cases, the effect of the osmotic gradient on the very delicate alveolar-capillary membrane increases its permeability and exacerbates fluid, electrolyte shifts and plasma.

Rapid CNS cooling before significant cardiac dysrhythmia provides cerebral protection in cold water submersion.

In submersion victims amount of swallowed water is much greater than aspirated, as a consequence 60% of patients vomit after a submersion event. Well-known complication with aspiration of gastric contents is pulmonary injury and increased possibility for acute respiratory distress syndrome.

Thype of the water does not matter

 

When the patient is rescued alive is the clinical picture determined predominantly by the amount of water has been aspirated and its effects. Osmotic gradient effects the very delicate alveolar capillary membrane increases its permeability and exacerbates fluid, plasma and electrolyte shifts.

We should also consider the precipitants of submersion injury which may be drugs or ethanol intoxication, cardiac arrest, hypoglycemia, seizure and attempted suicide or homicide.

Prehospital Care

The most important thing is early CPR, as it optimizes the outcome. This is the reason why there is a need to train laypersons in CPR.

If the patient is not breathing give 5 rescue breaths immediately, followed by 30 chest compressions and continuing with 2 rescue breaths and 30 compressions until signs of life reappear. Positive pressure bag-valve-mask ventilation should be administered.

If the heart is beating give only breaths, not CPR. Victims with only respiratory arrest usually respond after a few rescue breaths.

If the patient is spontaneously breathing, let him cough, place him in the recovery position and administer high-flow oxygen mask (15 liters of oxygen per minute).

If it is possible, resuscitate in the water (ventilation alone)

 

Endotracheal intubation and positive pressure ventilation are necessary if there is no recovery of spontaneous respiratory effort.

Obligatory transportation to ED is for the patients who have a loss or depressed consciousness, an observed period of apnoea and those who require a period of artificial ventilation.

Emergency Department Care

First steps are assessing and securing the airway, providing oxygen, determine core temperature and assisted ventilation as necessary.
If the patient is in cardiac arrest you should follow ACLS guidelines.

The following management shows the steps when the patient is not in cardiac arrest:

 

A. Airway

  • When the pulmonary examination is abnormal or there is oxygen requirement, admission or transfer to monitored bed is needed.
  • When the GCS is under 13 the patient should receive supplemental oxygen and ventilator support if needed.
  • The patient should be intubated when high-flow oxygen cannot maintain an adequate partial pressure of arterial oxygen.

B. Breathing

  • Arterial saturation should be between 92-96%. Treatment should be administered like ARDS: add PEEP, low tidal volumes, and permissive hypercarbia.
  • Supranormal levels of positive end-expiratory pressure are beneficial to recruit fluid-filled lung units. Special consideration should be taken to avoid lung over-distention and ventilate-associate lung trauma.
  • Avoid suction as it disrupts oxygenation and do not extubate early (lung injury may present later). Medications should not be administered through the endotracheal tube.

C. Circulation

  • We are looking for the presence of significant dysrhythmias, QT prolongation or ischemia with cardiac monitoring and an electrocardiogram.
  • If there is cardiopulmonary arrest or asystole when the patient comes to ED, we should consider discontinuing resuscitation efforts, because of profound neurologic handicaps.
  • There was not shown benefit in efforts to control cerebral edema, with use of mannitol, loop diuretics, hypertonic saline, fluid restriction and mechanical hyperventilation.
  • Continuous cardiac monitoring, pulse oximetry, temperature monitoring.

Varieties of tests in the ED include

  • Gastric tube, laboratory studies (frequent arterial blood gas measurements)
  • Chest radiography (initial chest radiographs may be unremarkable, even in the setting of severe and evolving pathologic process)

Risk Groups

  • Drowning is the leading cause of injury mortality in children 1 to 4 years of age.
  • Children can develop dilutional hyponatremia and seizures in freshwater near-drowning.
  • Children have hypothermia more quickly because of a lower ratio of body mass to surface area. There was no shown benefit in controlled hypothermia, barbiturate coma, and intracranial pressure monitoring.

Prognosis

There is no prognostic scale that accurately predicts long-term neurologic outcome. There is documented normal neurologic recovery even with fixed and dilated pupils, cardiovascular instability, prolonged submersions and persistent coma. Complete recovery within 48 hours is expected if there was no need for cardiopulmonary resuscitation on the scene or in ED. If there are no continuous neurologic and cardiovascular deficits shown, the patients should recover completely. Those who needed CPR in ED have a poor prognosis, because of significant anoxic or ischemic insult to the brain and other vital organs.

Disposition Decisions

Apnoea, hypoxia, unconsciousness, dysrhythmia or abnormal chest radiograph are signs for admission.

If ED resuscitation/CPR was required the patient should be admitted to the intensive care unit for continuous cardiopulmonary and frequent neurologic monitoring.

The patient can be discharged after 4-6 hour observation period if the Glasgow Coma Scale is 15, oxygen saturation over 94% on room air and if pulmonary examination does not reveal rales, rhonchi, wheezing, or retractions. We should warn the patient to return if mental status changes, pulmonary symptoms or fever occur.

References and Further Reading

  • Virtual Health Care Team [homepage on the Internet]. Near Drowning: [updated 2012 August 1]. Available from: http://shp.missouri.edu/vhct/case699/index.htm. Accessed March 23, 2016.
  • Rosen, P. M. Rosen’s emergency medicine: Concepts and clinical practice. 8th ed. Philadelphia: Elsevier Saunders; 2014;145(Pt 2):1941-1944.
  • Tintinalli, J. E.. Tintinalli’s emergency medicine: A comprehensive study guide. 7th ed. New York: McGraw-Hill; 2011.
  • David Szpilman, M.D., Joost J.L.M. Bierens, M.D., Ph.D., Anthony J. Handley, M.D., and James P. Orlowski, M.D. Drowning. New English Journal of Medicine. 2012; 366:2102-2110
  • Policy and Practice – WHO. http://www.who.int/bulletin/volumes/83/11/853.pdf
  • David Szpilman, M.D., Joost J.L.M. Bierens, M.D., Ph.D., Anthony J. Handley, M.D., and James P. Orlowski, M.D. Drowning. New English Journal of Medicine. 2012; 366:2102-2110.

Links To More Information