Drowning

Terminology

Wet, dry, or near drowning are not medically accepted terms and should not be used.

There is nothing “near” about drowning. It happened or it didn’t.

Drowning is:

“the process of experiencing respiratory impairment due to submersion or immersion in liquid.”

Drowning has three outcomes. This is a uniform way of reporting data after a drowning event is using the Utstein template:

1) Morbidity

2) No morbidity

3) Mortality

Submersion or immersion incident without evidence of respiratory impairment is considered a water rescue and not a drowning.


Pathophysiology

  1. A person holds their breath until water enters the mouth.
  2. This water is voluntarily spat out or swallowed.
  3. The next conscious response is breath holding which lasts around one minute.
  4. The inspiratory drive becomes to strong and some water is aspirated into the airways (reflexive swallowing).
  5. Laryngospasm occurs, but is rapidly terminated by the onset of brain hypoxia.
  6. Aspiration continues, and hypoxemia leads to the loss of consciousness and apnea.
  7. The initial cardiac rhythm is tachycardia, then bradycardia, then asystole.

– Adapted from Szpilman et. al.

On average, less than 30 mL of fluid or NO fluid enters the lungs. 


Clinical presentation

  1. Water washes out surfactant = frothy pulmonary edema
  2. Cellular Injury – alveolar collapse leads to atelectasis
  3. Hypoxic vasoconstriction due to V/Q mismatch
  4. Bronchospasm
  5. Inflamation

The main problem is NO OXYGEN TO THE BRAIN. This is a hypoxic cardiac arrest and should be treated as such. 


In-water Rescue (If properly trained)

“Reach, Throw, Row, Don’t GO” – Don’t become a victim

If properly trained, and the patient HAS A PULSE, mouth to mouth resuscitation can result and a 3 times greater likelihood of surviving as compared with taking the person first to land.

CPR will be ineffective. If the patient is in the water and has an arrest due to cardiac causes, rapidly extricate them. 


Cervical Spine Immobilization

 Incidence of cervical spine injuries is 0.5%-5%

Without obvious signs of trauma or a known fall or diving event, routine cervical spine immobilization is unnecessary and can delay providing oxygen to the brain.

If the patient is awake, follow standard spinal clearance algorithms.


Land Resuscitation

 Airway, Airway, Airway

formofasphyxia

 Start with basics: Mouth to mouth, mouth to mask, BVM, Etc.

Delay placing an advanced airway – restoring oxygenation is more important.

Cardiac arrest in drowning is due to hypoxia.

There is no place for “hands only CPR”

CPR only will only circulate blood with a severe oxygen debt that won’t be restored without positive pressure ventilation.

Beware of Acute Pulmonary Edema

 Water + Soap = Foam. Possibly lots of it. You don’t need to suction unless vomit or frank water is present. Suctioning foam will keep coming. Bag it down.

Use PEEP


The Heimlich maneuver

No.

Little water is aspirated into the lungs, and it only delays the administration of oxygen.


If patient is awake and/or has a pulse and is intubated

CPAP if not at risk for vomiting

If managed via an advanced airway, use an ARDS approach

  • Low tidal volumes: 6-8 cc/kg of ideal body weight
  • Respiratory rate to maintain eucapnea: 16-18
  • Increase PEEP and FiO2 in tandem to achieve and adequate SpO2

Who should be resuscitated?

 Per WMS Practice Guidelines:

“Minimal chance of neurologically intact survival with submersion time greater than 30 minutes in water greater than 43 degrees F.”

“Minimal chance of Minimal chance of neurologically intact survival with submersion time greater than 90 minutes in water less than 43 degrees F.”


When should resuscitative efforts cease?

 WMS Recommendation: After 25 minutes continuous CPR


What about cold water drowning?

A Dutch prospective of children who drowned in cold water showed that no child in asystole, who was resuscitated for more than 30 min survived without being neurologically devastated.

Another large study conducted by Quan et. al. involving adults who drowned in cold or very cold waters showed that of 1094 victims, the majority had bad outcomes. Those with good outcomes were likely to be submerged for less than 11 minutes.

Brown et. al found that there is a neuroprotective effect in avalanche victims, but not in those who asphyxiated first, then became hypothermic.

The mantra “they’re not dead until they’re warm and dead” appears to be overhyped, and more and more data suggests there’s not as much of a neuroprotective effect of cold water drowning as once thought, and that mantra is probably only applicable to the patient who becomes hypothermic before going into cardiac arrest or becoming hypoxic.


Disposition of an awake patient

Most patients who experienced a drowning incident requiring the need for EMS to be contacted should be transported for evaluation. Depending on where you practice, you may have to make a mission critical decision of whether or not to evacuate or continue with close monitoring of the patient.

Statistically, a person without a severe cough, frothy sputum or a foamy airway, and a normal cardiac examination has a mortality rate of 0%.

The more severe the symptoms, the higher the mortality:

triage of the drowning patient

References:

McIntosh, S. E., Opacic, M., Freer, L., Grissom, C. K., Auerbach, P. S., Rodway, G. W., … Hackett, P. H. (2014). Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Frostbite: 2014 Update. Wilderness & Environmental Medicine. https://doi.org/10.1016/j.wem.2014.09.001
Quan, L., Mack, C. D., & Schiff, M. A. (2014). Association of water temperature and submersion duration and drowning outcome. Resuscitation. https://doi.org/10.1016/j.resuscitation.2014.02.024
Suominen, P. K., & Vähätalo, R. (2012). Neurologic long term outcome after drowning in children. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. https://doi.org/10.1186/1757-7241-20-55
Szpilman, D., Bierens, J. J. L. M., Handley, A. J., & Orlowski, J. P. (2012). Drowning. New England Journal of Medicine. https://doi.org/10.1056/NEJMra1013317

Curbside to Bedside

Curbside to Bedside is a blogcast created by front line EMS Clinicians to provide simple and relevant initial and continuing prehospital EMS education.

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