Problem: An older adult client with severe dehydration is admitted to the intensive care unit (ICU) after being found unconscious on the floor of the home. ? Laboratory results include: ? sodium 122 mEq/L? hematocrit 56%? blood urea nitrogen (BUN) 38 mg/dL? The provider orders intravenous administration of D5W at 200 ml/hour to treat hypovolemia. Several hours after the infusion is started, the client has a generalized seizure. Which statement most accurately describes the cause of the seizure?