Florida State Paramedic Practice Exam

What serum electrolyte imbalance is likely to occur with fresh water drowning?

1. Hypernatremia

2. Hypokalemia

3. Hyponatremia

4. Hypercalcemia

The correct answer is: Hyponatremia

Freshwater drowning leads to a condition known as hyponatremia, which is characterized by a lower-than-normal concentration of sodium in the blood. When a person drowns in fresh water, the hypotonic nature of freshwater can cause the body's cells to absorb excess water, leading to dilution of sodium in the extracellular fluid. This influx of water into cells increases the intracellular fluid volume and decreases the osmolarity of the blood—resulting in a significant drop in serum sodium levels. Consequently, during freshwater drowning, the body attempts to balance the osmotic discrepancy but ends up in a state of hyponatremia, which can lead to serious neurological complications due to brain edema. Recognizing this electrolyte imbalance is crucial in the management and treatment of a patient who has experienced a freshwater drowning incident.