Drowning and Scuba Emergencies

Drowning and Scuba Emergencies

Drowning Definition

  • At the 2002 World Congress on Drowning in Amsterdam, experts proposed a unified definition of drowning to eliminate confusion stemming from various terms.

  • Definition: Drowning is a process resulting in primary respiratory impairment from submersion in a liquid medium.

  • The following terms are proposed for discontinuation:

    • Wet drowning

    • Dry drowning

    • Active drowning

    • Passive drowning

    • Near-drowning

    • Secondary drowning

    • Silent drowning

Submersion Events

  • Following breath-holding, laryngospasm occurs due to liquid presence in the oropharynx or larynx.

  • As the urge to breathe increases, laryngospasm relaxes, leading to gasping, and potential aspiration of liquid.

  • Asphyxia induces airway relaxation, allowing water intake into lungs; typically, individuals aspirate less than 4 ext{ mL/kg} of fluid.

Progression of Drowning

  • Laryngospasm Outcomes:

    • Dry Drowning: 10-15%

    • Wet Drowning: 85-90%

  • Consequences include:

    • Aspiration leading to cerebral hypoxia, acidosis, possible cardiac arrest, and subsequent brain injury or death.

Drowning Statistics (2018 Alberta Drowning Report)

  • Where do drownings occur?

    • Lakes: 28%

    • Rivers: 29%

    • Bathtubs: 19%

    • Pools: 8%

    • Hot Tubs: 4%

    • Other: 13%

  • Gender:

    • Women: 28%

    • Men: 72%

  • Time of Year:

    • Drownings are distributed unevenly throughout the year.

Risk Factors by Activity

  • Factors involved in drowning incidents include:

    • No Personal Flotation Device (PFD)

    • Capsizing

    • Alcohol consumption

    • Swimming alone

    • Poor swimming ability

Secondary Drowning

  • Defined as pulmonary function deterioration after deficient gas exchange, linked to surfactant loss or inactivation.

  • The term is gradually becoming obsolete due to better understanding.

Laryngospasm

  • Laryngospasm: A sudden spasm of the vocal cords causing breathing difficulties.

  • In drowning scenarios, this simulates airway obstruction.

  • Usually resolved with a forceful ventilation.

Cold Water & Hypothermia

  • Hypothermia onset times vary based on temperature exposure:

    • Belief information indicates expected effects in intervals from 0-30 minutes in cold water.

1-10-1 Principle for Cold Water

  • 1 minute: To gain breathing control.

  • 10 minutes: Of meaningful movement before exhaustion.

  • 1 hour: Until loss of consciousness from hypothermia.

Emergency Responder Protocol

  1. Standard approach includes:

    • Clear airway, apply oxygen.

    • If patient requires transport post-submersion, they must go to the hospital regardless of apparent injury.

    • Specific protocols for dealing with hypothermic cardiac arrest vary based on water temperature.

    • Always ensure patient safety by monitoring vital signs and readiness for potential advanced interventions.

Scuba Emergencies

The Physics of Pressure and Gas

  • Gas Characteristics: Gases are compressible, but liquids are not.

  • Pressure increases with depth, impacting air-filled cavities like the lungs and sinuses.

Barotrauma

  • Definition: Injuries caused by pressure changes on air-filled body cavities.

  • Common forms include middle ear and pulmonary barotrauma which occur due to rapid pressure changes (elevation in pressure on descent or rapid ascent).

Types of Barotrauma

  • Inner Ear Barotrauma: Damage linked to pressure differences across ear windows; symptoms include vertigo and nausea.

  • Pulmonary Barotrauma: Can lead to air embolism, pneumonia, or pneumothorax when ascending too quickly or holding breath.

Nitrogen Narcosis

  • Definition: Altered mental state due to high nitrogen partial pressure, typically at greater depths underwater.

  • Anesthesia-like effect on consciousness, with potentially serious safety implications.

Decompression Sickness

  • Known as The Bends; develops from nitrogen bubble build-up during rapid ascent.

  • Treatment includes immediate oxygen therapy followed by recompression therapy.

Vocabulary

  • Barotrauma

  • Embolism

  • Hypoxemia

  • Laryngospasm

  • Hypothermia

  • Drowning Morbidity

  • Mortality