Water intoxication, also known as water poisoning, occurs when too much water is consumed too quickly, causing an electrolyte imbalance that can lead to cellular swelling, especially in the brain. A 28-year-old woman died after drinking large amounts of water during a radio station contest. Drinking excessive water too quickly can cause the body's electrolyte balance to shift, causing cells including brain cells to swell. Symptoms range from headache to seizures and brain damage. Risk factors include low body mass, endurance exercise without electrolyte replenishment, psychiatric conditions, and medical treatment that does not balance fluids and electrolytes. Prevention involves drinking water in moderation over time rather than large volumes at once. Treatment focuses on fluid restriction
2. Water intoxication
Strange but True: Drinking Too Much Water Can
Kill
In a hydration-obsessed culture, people can and do
drink themselves to death.
Earlier this year, a 28-year-old California woman died
after competing in a radio station's on-air water-
drinking contest. After downing some six liters of
water in three hours in the "Hold Your Wee for a Wii"
(Nintendo game console) contest, Jennifer Strange
vomited, went home with a splitting headache, and
died from so-called water intoxication
3. Intro: water intoxication
Water intoxication, also known as water poisoning or
dilutional hyponatremia, is a potentially fatal
disturbance in brain functions that results when the
normal balance of electrolytes in the body is pushed
outside safe limits by over-hydration.
Water, just like any other substance, can be considered a
poison when over-consumed in a specific period of time.
Water intoxication mostly occurs when water is being
consumed in a high quantity without giving the body the
proper nutrients it needs to be healthy.
4. Cont;
Excess of body water may also be a result of a medical
condition or improper treatment; see "hyponatremia" for
some examples.
Water is considered the least toxic chemical
compound, with a LD50 of 90 g/kg or more in rats.
5. How can happen
Under normal circumstances, accidentally consuming
too much water is exceptionally rare. Nearly all deaths
related to water intoxication in normal individuals have
resulted either from
1. water drinking contests in which individuals attempt
to consume large amounts of water, or
2. long bouts of intensive exercise during which
electrolytes are not properly replenished, yet huge
amounts of fluid are still consumed
6. Cont:
Moreover, water cure, a method of torture in which the
victim is forced to consume excessive amounts of water,
can cause water intoxication.
7. The Water Torture — Facsimile of a woodcut in J. Damhoudère's
Praxis Rerum Criminalium, Antwerp, 1556.
8. Risk factors
• Low body mass (infants)
It can be very easy for children under one year old to absorb too
much water, especially if the child is under nine months old.
Because of their small body mass, it is easy to take in a large
amount of water relative to body mass and total body sodium
stores
• Endurance sports
Marathon runners are susceptible to water intoxication if they
drink too much while running. This is caused when sodium
levels drop below 135 mmol/L when athletes consume large
amounts of fluid. This has been noted to be the result of the
encouragement of excessive fluid replacement by various
guidelines. This has largely been identified in marathon runners
as a dilutional hyponatremia.
9. Cont.
• Overexertion and heat stress
Any activity or situation that promotes heavy sweating can lead
to water intoxication when water is consumed to replace lost
fluids. Persons working in extreme heat and/or humidity for
long periods must take care to drink and eat in ways that help to
maintain electrolyte balance. People using drugs such as MDMA
(often referred to colloquially as "Ecstasy") may overexert
themselves, perspire heavily, and then drink large amounts of
water to rehydrate, leading to electrolyte imbalance and water
intoxication .
• Psychiatric conditions
Psychogenic polydipsia is the psychiatric condition in which
patients feel compelled to drink large quantities of water, thus
putting them at risk of water intoxication. This condition can be
especially dangerous if the patient also exhibits other psychiatric
indications (as is often the case), as the care-takers might
misinterpret the hyponatremic symptoms.
10. Cont.
• Iatrogenic
When an unconscious person is being fed intravenously (for
example, total parenteral nutrition) or via a nasogastric tube the
fluids given must be carefully balanced in composition to match
fluids and electrolytes lost. These fluids are typically hypertonic,
and so water is often co-administered. If the electrolytes are not
monitored (even in an ambulatory patient) either hypernatremia
or hyponatremia may result.
N.B:
Some neurological/psychiatric medications (Oxcarbazepine,
among others) have been found to cause hyponatremia in some
patients. Patients with diabetes insipidus are particularly
vulnerable due to rapid fluid processing
11. Pathophysiology
At the onset of this condition, fluid outside the cells has an
excessively low amount of solutes (such as sodium
(hyponatremia) and other electrolytes) in comparison to
that inside the cells causing the fluid to shift through (via
osmosis) into the cells to balance its concentration. This
causes the cells to swell. In the brain, this swelling
increases intracranial pressure (ICP).
It is this increase in pressure which leads to the first
observable symptoms of water intoxication: headache,
personality changes, changes in behavior, confusion,
irritability, and drowsiness.
12. Cont.
These are sometimes followed by difficulty breathing
during exertion, muscle weakness & pain, twitching, or
cramping, nausea, vomiting, thirst, and a dulled ability to
perceive and interpret sensory information
As the condition persists, papillary and vital signs may
result including bradycardia and widened pulse pressure.
The cells in the brain may swell to the point where blood
flow is interrupted resulting in cerebral edema. Swollen
brain cells may also apply pressure to the brain stem
causing central nervous system dysfunction. Both cerebral
edema and interference with the central nervous system
are dangerous and could result in seizures, brain damage,
coma or death.
13. Prevention
It's Not How Much You Drink, It's How Fast You
Drink It!
The kidneys of a healthy adult can process fifteen liters of water a
day! You are unlikely to suffer from water intoxication, even if you
drink a lot of water, as long as you drink over time as opposed to
intaking an enormous volume at one time. As a general guideline,
most adults need about three quarts of fluid each day. Much of that
water comes from food, so 8-12 eight ounce glasses a day is a
common recommended intake. You may need more water if the
weather is very warm or very dry, if you are exercising, or if you are
taking certain medications. The bottom line is this: it's possible to
drink too much water, but unless you are running a marathon or an
infant, water intoxication is a very uncommon condition.
14. Cont.
Water intoxication can be prevented if a person's
intake of water does not grossly exceed his or her
losses.
15. Treatment
Mild intoxication may remain asymptomatic and require
only fluid restriction. In more severe cases, treatment
consists of:
• Diuretics to increase urination, which are most
effective for excess blood volume. Such as furosamide
(lasix)
• Vasopressin receptor antagonists. Lixivaptan
Mozavaptan Satavaptan Tolvaptan
16. References
Noakes TD, Wilson G, Gray DA, Lambert MI, Dennis SC
(October 2001). "Peak rates of diuresis in healthy humans
during oral fluid overload". S. Afr. Med. J. 91 (10): 852–7.
PMID 11732457. — refers to a renal excretion capacity of
3 ml/h
http://learn.caim.yale.edu/chemsafe/references/dose.html
[1] — see to Section 11:
Toxicological Information for the LD50 verification Water
Intoxication in Infants Almond CS, Shin AY, Fortescue EB,
et al. (April 2005).
"Hyponatremia among runners in the Boston Marathon".
N. Engl. J. Med. 352 (15): 1550–6.
doi:10.1056/NEJMoa043901. PMID 15829535.