During transurethral resection of the prostate surgery, a sterile irrigation solution is used to keep the surgical area clean and to prevent distribution of cancer cells if they are present. This solution is low in sodium. When this solution enters the bloodstream, it can lower the sodium level in the body.
Hyponatremia, or low blood sodium, can cause disorientation, nausea, vomiting, fatigue, and in severe cases, brain edema and seizures.
Treatment varies based upon the severity of the low sodium, which can be determined by a simple blood test. Treatment may be as simple as restricting fluid intake, or may involve IV medication, or the administration of salt.