Review Question - QID 213535

A 44-year-old woman is brought to the emergency department for confusion and lethargy for the past 2 hours. Per the husband, the patient was behaving weirdly and forgot how to get to the bathroom at her house. She was also difficult to arouse from her nap. The husband denies any fever, weight loss, headaches, dizziness, chest pain, or gastrointestinal changes. He reports that she had frequent diarrhea over the past 3 days but attributed it to food poisoning. In the emergency room, the patient has a 1-minute episode of seizure activity. Following initial resuscitation and stabilization, laboratory studies are performed and the results are shown below.

Hemoglobin: 13 g/dL
Hematocrit: 38%
Leukocyte count: 7,600/mm^3 with normal differential
Platelet count: 170,000/mm^3

Serum:
Na+: 125 mEq/L
Cl-: 90 mEq/L
K+: 3.2 mEq/L
HCO3-: 20 mEq/L
BUN: 22 mg/dL
Glucose: 101 mg/dL
Creatinine: 1.0 mg/dL
Thyroid-stimulating hormone: 3.2 µU/mL
Ca2+: 9.3 mg/dL
AST: 19 U/L
ALT: 22 U/L

What is the most appropriate treatment for this patient?