Table of Contents
Drowning occurs when an individual is immersed in water
and takes water into the lungs, subsequently not being able
to breath. Drowning is divided into delayed drowning or secondary
drowning, and immersion incidents. For Survive Outdoors, we
are going to limit this to drowning and dry drowning incidents.
Approximately 140,000 deaths occur worldwide from drowning
annually. There are approximately 9,000 deaths/year in the
United States. This is second only to motor vehicle accidents.
64% of drowning victims are less than 30 years old, and 26%
are less than 5 years old.
One interesting, and important note is that the proficiency
at swimming is not related to drowning rates.
Gender differences need to be considered. White males have
a greater incidence of drowning than white females. However
white males have a greater ability to swim overall. Many individual
do not die from drowning, but suffer from secondary effects
such as hypothermia. For specifics of hypothermia, please
see the hypothermia section on Survive Outdoors.
There is a large difference between freshwater aspiration
and seawater aspiration. For more involved pathophysiology
of the differences between freshwater and seawater aspiration,
I would strongly advise you to seek other references, specifically
Wilderness Medicine by Auerbach. In general, seawater aspiration
has a higher mortality than freshwater. The reason for this
is seawater has an osmolarity 4 times higher than that of
the blood. When seawater is aspirated into the lungs, due
to the high osmolarity, you get a transfer of plasma fluid
directly into the small pockets of the lungs called alveoli
and the lung parenchyma resulting in severe pulmonary edema,
which is fluid in the lungs. For the general lay person, we
need to think back to our biology classes in high school and
cell membranes, and how chemicals like sodium and potassium
cross membrane cell walls. That is what happens when you aspirate
seawater, hence the severe reaction and higher mortality rate.
Shallow Water Blackout
Shallow water blackout is an event where an individual hyperventilates
before they enter the water, common in endurance events and
underwater swims. According to Dr. Auerbach, hyperventilation
reduces the arterial carbon dioxide pressure without increasing
oxygen storage. During swimming activity, the body then starts
using stored oxygen in muscles before the classic carbon dioxide
stimulus tells you to breathe, causing one to return to the
surface to breathe. When this occurs, the victim usually blacks
out and a drowning episode occurs. It is never advisable to
hyperventilate before swimming. It increases your chances
of causing greater harm than good. This author has frequently
seen this occur in swimming pool scenarios, where teenagers
are trying to compete in underwater swim contests such as
who can swim the longest underwater. What appears to be a
very harmless event can turn sour very quickly. Please refer
to drowning and dry drowning for treatment.
The statistics vary, but somewhere between 15-20% of individuals
who drown have what is called dry drowning. This is specifically
a laryngospasm in response to water just starting to be taken
into the lungs. It is a natural physiological mechanism for
the larynx to spasm, stopping the water from entering the
lungs. There is no evidence at this time to suggest that these
individuals, since they do not have water in their lungs,
would be better off treatment-wise, than others who do have
water in their lungs, contrary to popular opinion. Treatment
for these individuals remains the same as in a drowning incident,
to get oxygenation to their lungs to get them to start breathing
Predicting outcomes in near drowning scenarios
In any medical emergency, it would be great to be able to
predict the outcome. In many cases this cannot be done. It
is not an exact science. However many researchers have been
able to look at some prognostic factors through large sample
populations. There are many factors that impact the outcomes
in cases of near drowning. These include but are not limited
- Length of submersion;
- Length of time of being unconscious;
- Water temperature;
- Expedience of recovery and starting of treatment.
Near drowning victims who are alert, or at least have good
pupillary reflex and are not in a coma should do well. Individuals
who have been submerged greater than 10 minutes and have treatment
resuscitation lasting longer than 25 minutes have usually
less than a 5% chance of recovery.
In the journal of American College of Emergency Physicians,
1979. Orlowski lists unfavorable prognostic factors of individuals
of near drowning as follows:
- Age less than 3 years;
- Estimates submersion time longer than 5 minutes;
- No resuscitation attempt for at least 10 minutes after
- Patient is in a coma on admission in the emergency dept.;
- The have an arterial blood gas measurement of pH 7.1 or
Treatment for Near Drowning
Outdoor treatment for near drowning
Administering CPR and assisting an individual
in breathing are clearly the most important treatment interventions
in victims of near drowning episodes. Mouth to mouth ventilation
is still the treatment of choice in the outdoors. Attempting
to perform cardiac compressions in the water is also a possibility,
although very difficult to perform. In the last 30 years,
this author has attempted to perform cardiac compressions
on two occasions, one with success and one not.
There are really no available studies showing
good circulation with cardiac compressions in the water. However
the attempt should be made if there is cardiac arrest. Mouth
to mouth ventilation should continue.
The following treatment discuss is based on
having next to nothing on hand with you in an outdoor setting.
Most individuals in the outdoors will not have float boards.
However if one can improvise and has anything hard that can
be placed on a victim’s back, this can be beneficial.
This can be anything from a paddle to a boat seat that can
be taken off and used in the water to help perform compressions.
It is also helpful to have another individual with you. Once
ashore, the individual should be laid in a supine position,
with the head neither up nor down, parallel to the beach,
as in a head up position, there is concern about intracranial
pressure building. Respirator drainage and gastric drainage
by pushing on the victim’s belly, or turning the victim
over and perform the Heimlich maneuver have shown no great
improvement in outcome. However if an individual has swallowed
a large amount of water, and their stomach is distended, this
can interfere with mouth to mouth ventilation, so it may be
very beneficial in this situation to push on the stomach to
expel water, turning the victim’s head sideways, or
rolling the victim on his side, at which point ventilations
Regarding near drowning incidents, The American
Heart Association advises against the Heimlich maneuver unless
there is gross blockage.
Healthcare Provider: Medical Treatment
In-hospital management of asymptomatic
victims of submersion incidents
- Check the airway.
- Supplemental oxygen, 12-15 liters/minute.
- Pulse Oximetry and/or arterial blood gas.
- Obtain a thorough history of the incident
- Underlying causes, any history of epilepsy,
drugs, heart attack, arrhythmias, or cerebral vascular accidents.
- Take the vital signs every 10 minutes.
- Draw bloods: CBC, complete metabolic panel,
assess blood urea, nitrogen, platelets, PT and PTT.
- Strongly consider a blood alcohol level
and toxicology screen.
- Observe all patients; they should be kept
for at least 4-6 hours before discharge.
In-hospital management of symptomatic victims
of submersion incidents
- Check the airway.
- Supplemental oxygen with a non-breathing
mask, 12-15 liters/minute.
- Consider endotracheal intubation for comatose
patients and patients unable to maintain an oxygen level
above 90 mm. of mercury on a high flow oxygen mask.
- Check vital signs.
- Start an intravenous line.
- Draw blood for electrolytes, BUN, platelets,
PT, PTT, arterial gas studies are imperative, urinalysis.
- Administer bi-carb according to blood
- Chest x-rays, cervical spine x-rays, if
concerned about neck trauma.
- Nasogastric tube and in-dwelling urinary
- Admit all patients with abnormal vital
signs and abnormal findings on blood values.
1. Paul S. Auerbach, Wilderness
2. Greenbaum, DM, et al., Continuous
Positive Airway Pressure without Tracheal Intubation
in Spontaneously-breathing patients,
3. Ornato, JP: The Resuscitation
of Near Drowning Victims,
4. Pearn, JH: Secondary Drowning in Children, British
Medical Journal, 1980.
5. Shelhamer, JH, Nathanson, C, Positive
and Expiratory Pressure in Adults,
6. Fisher, B., Peterson, B., Hicks, G.: Use of Brain
Stem Auditory-Evoked Response Testing to Assess Neurologic
Outcome Following Near Drowning in Children. Critical
Care Medicine, 1992.
7. Gooden, BA: Why Some People Do Not Drown: Hypothermia
vs. The Diving Response, Medical
Journal of Australia, 1992.
8. Kemp, AM, Sibert, JR: Outcome in Children Who Nearly
Drown, British Isles Study, British
Medical Journal, 1991.
9. Schuman, Shuman, et al., The Iceberg Phenomenon of
Near Drowning, Critical
Care Medicine, 1976.