What are the risks of acute water intoxication?

From the Guidelines

The risks of acute water intoxication include seizure, coma, and death due to acute cerebral edema.

Risks and Symptoms

• Mental status changes, with potential collapse, are associated with acute water intoxication, also known as exercise-associated hyponatremia (EAH) 1.
• The incidence of EAH in marathon runners has been reported to be between 3 and 22% 1.
• Risk factors for EAH include excessive fluid consumption, altered renal function, longer race times, female sex, and low body mass index 1.

Prevention and Management

• Education of athletes on potential individual risks and preventative measures, such as measuring body weight before and after long events, is crucial 1.
• Athletes should not gain weight and ideally should not lose more than 2-3% of their pre-training weight 1.
• Medical providers should be aware of presenting symptoms of symptomatic hyponatremia and have a plan in place for rapid identification and treatment, including oral hypertonic solutions and 3% sodium chloride solution for more severe cases 1.

From the Research

Risks of Acute Water Intoxication

The risks of acute water intoxication are significant and can be life-threatening. Some of the key risks include:

• Cerebral edema, which can lead to catastrophic consequences 2
• Pulmonary edema, which can cause respiratory distress 2
• Hyponatremia, which can lead to seizures, coma, and even death 3, 4
• Hypotension, which can cause dizziness, fainting, and decreased blood flow to vital organs 4
• Diffuse third-spacing, which can lead to hypovolemic shock and organ failure 4

Factors Contributing to Acute Water Intoxication

Several factors can contribute to the development of acute water intoxication, including:

• Excessive water intake, particularly in individuals with normal renal function 3
• Increased levels of antidiuretic hormones, which can reduce renal excretion of water 3
• Impaired urine dilution, which can occur in individuals with certain medical conditions or those undergoing urine drug testing 5
• Intake of more than 1 L of water, which can overwhelm the kidney's dilutional capacity of urine 5

Clinical Manifestations

The clinical manifestations of acute water intoxication can be non-specific and may include:

• Symptoms of cerebral dysfunction, such as headache, nausea, and vomiting 2, 5
• Respiratory distress, including shortness of breath and coughing 2
• Cardiovascular instability, including hypotension and tachycardia 4
• Gastrointestinal symptoms, including abdominal pain and diarrhea 3