Drowning and Scuba Emergencies Notes

Drowning Overview

• Consensus Definition of Drowning

  • Established in 2002 at the World Congress on Drowning in Amsterdam.

  • Drowning is defined as a process resulting in primary respiratory impairment from submersion in a liquid.

  • Various terms like wet drowning, dry drowning, active drowning, and others are now discarded for clarity.

Submersion Events

• Initial Phase

  • Laryngospasm triggers after breath holding due to liquid presence in larynx.

  • Laryngospasm causes temporary airway blockage.

• Breathing Drive

  • Urge to breathe increases, leading to involuntary gasps, potentially resulting in aspiration of water.

  • Most patients aspirate less than 4 ext{ mL/kg} of fluid.

• Asphyxia Outcome

  • After asphyxia, relaxation of airway may happen, allowing water to enter lungs.

Drowning Statistics

• Location of Incidents (2018 Alberta Drowning Report):

  • Bathtubs: 19%

  • Rivers: 29%

  • Pools: 8%

  • Hot Tubs: 4%

  • Other: 13%

  • Lakes: 28%

• Gender Distribution

  • Women: 28%

  • Men: 72%

Risk Factors by Activity

• Activities with high risk include:

  • No Personal Flotation Device (PFD)

  • Capsizing

  • Alcohol use

  • Swimming ability

  • Conditions (e.g., being alone)

Secondary Drowning

• Defined as deterioration of pulmonary function post-immersion due to loss/inactivation of surfactant.

• Term is becoming obsolete.

Laryngospasm

• Brief spasm of vocal cords making it difficult to speak or breathe, often simulated as airway obstruction.

• Can often be resolved through forceful ventilation.

Hypothermia Considerations

• 1-10-1 Principle

  • 1 Minute to regain breathing control

  • 10 Minutes of meaningful movement

  • 1 Hour before loss of consciousness due to hypothermia.

Emergency Response**

• Any patient who has experienced submersion must be transported to a hospital.

• Patient Safety Considerations

  • Ensure clear airway, apply oxygen

  • Use specific protocols for cold water vs warm water incidents.

Scuba Emergencies Overview

• Pressure and Gas Physics

  • Gases are compressible; liquids are not

  • Air-containing cavities in the body are affected by external water pressure.

Barotrauma**

• Definition

  • Barotrauma occurs when external water pressure exceeds the air pressure in the body’s air spaces.

• Squeeze

  • Pain or injury due to pressure imbalance, particularly in ears and sinuses.

Ear Barotrauma**

• Most common in recreational diving; properly equalizing pressure can prevent it.

• Middle Ear Barotrauma Symptoms

  • Pressure and pain during descent, muffled hearing, dizziness.

Inner Ear Barotrauma

• Damage to round or oval windows causing vertigo, nausea, and hearing loss.

Pulmonary Barotrauma**

• Caused by expanding air trapped in lungs; can lead to serious conditions such as gas embolism.

• Prevention involves avoiding breath-holding and rapid ascents.

Decompression Sickness** (DCS)

• Caused by nitrogen bubble formation during rapid ascent.

• Treatment involves timely oxygen therapy and recompression in a chamber.

Vocabulary**

• Key terms:

  • Barotrauma

  • Embolism

  • Hypoxemia

  • Laryngospasm

  • Hypothermia

  • Drowning

  • Morbidity- the chances of death

  • Mortality- percentage of fatalities due to an incident or disease