Does a patient with suspected water intoxication, particularly an endurance athlete with severe symptoms such as headache, nausea, vomiting, seizures, or altered mental status, need to go to the Emergency Room (ER) for evaluation and treatment?

Does Water Intoxication Need Emergency Room Evaluation?

Yes, patients with suspected water intoxication presenting with severe symptoms—including headache, nausea, vomiting, seizures, or altered mental status—require immediate emergency room evaluation and treatment, as this represents a life-threatening medical emergency that can progress to cerebral edema, coma, and death. 1, 2, 3

Severity-Based Approach to Emergency Care

Severe Symptoms Requiring Immediate ER Transfer

Patients presenting with any of the following require emergency department evaluation and treatment 1, 2:

• Altered mental status, confusion, or decreased level of consciousness 1, 2, 3
• Seizures or tonic-clonic activity 1, 4, 5
• Coma or obtundation 3, 6
• Collapse with mental status changes 1

These symptoms indicate hyponatremic encephalopathy with potential cerebral edema, which has caused multiple deaths and requires hypertonic saline administration 1, 2.

Mild to Moderate Symptoms

Patients with milder symptoms still warrant urgent medical evaluation 1:

• Nausea, vomiting, or bloating 1, 3
• Headache without confusion 1
• Weakness or muscle cramps 7, 3

While these patients may be managed with oral hypertonic solutions if able to drink and monitored closely, the threshold for ER evaluation should be low given the potential for rapid deterioration 1.

Critical Treatment Considerations

Emergency Management Protocol

For severe symptomatic hyponatremia, the American College of Sports Medicine recommends 2, 3:

• Immediate administration of 3% hypertonic saline as 100 mL boluses over 10 minutes 2
• Repeat up to three times at 10-minute intervals until symptoms resolve 2
• Target correction of 4-6 mEq/L increase within first 6 hours, maximum 8-10 mEq/L in 24 hours 2, 3

Why ER Evaluation is Essential

The emergency department provides critical capabilities that cannot be replicated at home 1, 2:

• Point-of-care serum sodium testing to confirm diagnosis and guide treatment 1
• Hypertonic saline administration for severe cases 1, 2, 3
• Monitoring for overcorrection to prevent osmotic demyelination syndrome 2, 3
• Airway management for patients with altered mental status or seizures 1

Common Pitfalls to Avoid

Do Not Delay Transfer for Diagnostic Testing

The most critical error is delaying treatment while pursuing imaging or other diagnostics 8. Computed tomography should not delay sodium correction therapy in patients with obvious clinical symptoms of severe hyponatremia 8.

Avoid Fluid Administration During Transport

A crucial caveat: EMS providers must be educated to restrict intravenous hydration during transport of patients with suspected water intoxication, as additional hypotonic fluids will worsen the condition 1. Fluid restriction is essential during transfer 1, 6.

Recognize the Mortality Risk

Water intoxication has been responsible for multiple deaths in otherwise healthy individuals 1, 4, 8. Even in patients with normal renal function, excessive water intake combined with increased antidiuretic hormone secretion (from exercise, stress, or illness) can be fatal 8.

Risk Factors Requiring Lower Threshold for ER Evaluation

Certain populations warrant immediate ER evaluation even with milder symptoms 1:

• Endurance athletes with exercise duration >4 hours 1, 2
• Patients with known excessive fluid consumption 1
• Female athletes or those with low body mass index 1
• Psychiatric patients with polydipsia 4
• Anyone with rapid symptom progression 9, 3

The incidence of exercise-associated hyponatremia ranges from 3-22% among marathon runners, making this a common and serious concern 1.