Drowning: Causes

Pathogenesis (development of disease)

Typical drowning is divided into the following sequential stages of suffocation:

  1. Pre-submersion: Stage of inspiration (inhalation of air) at the water surface.
  2. After sinking: Willful cessation of breathing (apnea phase) → accumulation of CO2 (carbon dioxide) in the blood (hypercapnia).
  3. CO2 retention irritates the respiratory center and causes another gasp for air, against which the drowning person cannot defend himself → exhalation of air and inhalation of water → the water enters the lungs and mixes with air and mucus → dyspnea (shortness of breath)
  4. Asphyxiation convulsions (choking spasms) occur → loss of consciousness.
  5. Preterminal paralysis due to lack of oxygen to the brain → death.

The struggle for survival can last up to 15 minutes with repeated surfacing and gasping for air.

In atypical drowning, the person suffocates rapidly, that is, repeated gasping for air at the water surface fails to occur. Inspiration (inhalation of air) is absent; instead, water is aspirated (inhaled). The typical signs of drowning are much less pronounced in this species.

The drowning victim’s chances of survival are partly determined by water temperature and hypothermia (hypothermia).Water temperature affects the efficiency of muscle cells. The cold also reduces the speed of stimulus transmission in the nerve pathways. Muscle contractions, grip strength and hand coordination decrease rapidly (→ cold paralysis). Affected persons are no longer able to put on a buoyancy aid, let alone rescue themselves from the water under their own power.Hypothermia is said to occur when the tympanic temperature (measured in the ear) is below 35°C. Whether and how quickly hypothermia occurs depends not only on the water temperature but also on the body mass, body fat, insulating clothing, water movement and the current nutritional status of the drowning victim. Hypothermia itself can lead to death, for example, if someone collapses on the ice. From a water temperature of below 28°C, the body temperature cannot be maintained permanently.

The following table shows the maximum survival times in cold water:

Water temperature Time to unconsciousness Possible survival time
0,3 °C <15 minutes up to 45 minutes
0,3-4,5 °C 15-30 minutes 30-90 minutes
4,5-10,0 °C 30-60 minutes 1-3 hours
10,0-15,5 °C 1-2 hours 1-6 hours
15,5-21,0 °C 2-7 hours 2-40 hours
21,0-26,5 °C 2-12 hours 3 hours to (undefined)
> 26,5 °C (indeterminate) (undefined)

Etiology (causes)

Typical drowning (drowning death).

Biographical causes

  • Refugees – the majority of asylum seekers are non-swimmers.

Behavioral causes

  • Consumption of stimulants
    • Alcohol – reaction capacity and coordination ability of the drowning person are reduced as a result.
  • Drug use
  • Poor physical condition
  • Inexperienced swimmers
  • Overestimation of their own strength
  • Cocky behavior

Atypical drowning

Causes related to disease

  • The person is forcibly pushed/brought under water (homicide) or is in a vehicle that is sinking due to an accident.
  • Unconsciousness due to traumatic brain injury (TBI) – e.g., head on or accidents resulting in falling into water, e.g., boating accidents