system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 59-year-old Caucasian man with a history of hypertension and emphysema is brought to the hospital because of progressive lethargy and confusion. The patient has been experiencing poor appetite for the past 3 months and has unintentionally lost 9 kg (19.8 lb). He was a smoker for 35 years and smoked 1 pack daily, but he quit 5 years ago. He takes lisinopril and bisoprolol for hypertension and has no allergies. On examination, the patient appears cachectic. He responds to stimulation but is lethargic and unable to provide any significant history. His blood pressure is 138/90 mm Hg, heart rate is 100/min, and his oxygen saturation on room air is 90%. His mucous membranes are moist, heart rate is regular without murmurs or an S3/S4 gallop, and his extremities are without any edema. His pulmonary examination shows mildly diminished breath sounds in the right lower lobe with bilateral wheezing. His laboratory values are shown:
Sodium 110 mEq/L
Potassium 4.1 mEq/L
Chloride 102 mEq/L
CO2 41 mm Hg
BUN 18
Creatinine 1.3 mg/dL
Glucose 93 mg/dL
Urine osmolality 600 mOsm/kg H2O
Plasma osmolality 229 mEq/L
WBC 8,200 cells/mL
Hgb 15.5 g/dL
Arterial blood gas pH 7.36/pCO2 60/pO2 285
Chest X-ray demonstrates a mass in the right upper lobe. What is the most appropriate treatment to address the patient’s hyponatremia?
assistant
3% saline at 35 mL/h