A 75 -year-old male patient, a case of chronic obstructive pulmonary disease (COPD), was transferred from another hospital with complaints of fever, increased breathlessness for 5 days, and altered sensorium since yesterday. He also had an episode of seizure yesterday. He was being managed on the lines of acute exacerbation of COPD with cor pulmonale with pneumonia. He received antibiotics and diuretic therapy in the previous hospital. On evaluation, his laboratory values showed hemoglobin 13 g/dL, packed cell volume of 38.5%, serum sodium 160 mEq/L, serum potassium 3.0 mEq/L, serum urea 146 mg/dL, and serum creatinine of 1 mg/dL.