An iatrogenic metabolic encephalopathy in a nonagenarian: The dilemma of a critical miss as a possible social dismissal
A 93-year-old male, 70 kg, 165 cm, was admitted to (the first of three hospitals) with a diagnosis of congestive heart failure attributed to right ventricular dysfunction. He required a walker for ambulation. He had a past medical history of a coronary artery disease, atrial fibrillation, mitral regurgitation, aortic stenosis, diverticular bleeding, hypertension, advanced chronic kidney disease, gout (remote), and nonAlzheimer's dementia. His surgical history included coronary artery bypass grafting with mitral valve and aortic valve replacement (tissue valves). His medications were donepezil for dementia, calcium carbonate, potassum chloride, isosorbide mononitrate, metamucil, pantoprazole, diltiazem, hydralazine, and bumetanide.\nThe laboratory evaluation demonstrated: Sodium 140 mmol/L, potassium 4.0 mmol/L, chloride 95 mmol/L, serum bicarbonate 36 mmol/L, phosphorus 3.4 mg/dl, magnesium 2.2 mg/dL, glucose 108 mg/dL, blood urea nitrogen (BUN) 73 mg/dL, creatinine 2.13 mg/dL, glomerular filtration rate (GFR) 29 mL/min, occult blood negative, total protein 6.3 g/dL, albumin 3.8 g/dL, thyroid function tests were normal, hemoglobin 9.7 g/dL, hematocrit 29.3%, white blood cell count 4.6 K/μL, and platelets 90 K/μL.\nPhysical examination revealed bilateral pulmonary rales, tachypnea, pedal edema, and rate-controlled atrial fibrillation (confirmed by electrocardiogram). Chest roentgenogram showed bilateral pleural effusions and pulmonary edema.\nA furosemide infusion promoted a 6 kg loss in 5 days; tachypnea, pedal edema, pulmonary edema, and pleural effusions improved. Concurrently he complained of leg pain and received tramadol 50 mg every 8 hours. His cognitive function worsened over 72 hours (days 3-5 of diuresis). He also became incontinent, needed skilled nursing care, and was transferred to a covalesent facility where he was difficult to arouse upon arrival. He had lost intravenous access and none was started. No laboratory studies were drawn. The staff suggested that the patient be made “comfort care” only. The next morning his condition remained unchanged. The family expressed concern and transferred the patient to a third institution.\nSubsequent examination revealed a Glasgow coma scale of 10, mild bilateral rales, rate controlled atrial fibrillation, no pretibial edema, and an edematous left foot with an erythematous, warm great toe. Urine output was diminished. Laboratory examination revealed a BUN of 81 mg/dL (GFR < 30 mL/min), potassium, sodium, and chloride were normal, and serum bicarbonate 43 mmol/L, and arterial blood gas was pH of 7.37, PaCO2 65, and PaO2 of 90 (2 liters nasal cannula). His uric acid level was 450 μmol/L.\nHe received crystalloid fluids at 100 mL/hour for 24 hours, and bilevel noninvasive mechanical ventilation 12/4 cm H2O. He subsequently improved over 36 hours. His ME from a compensated metabolic alkalosis with hypercapnea was corrected, and urine output improved. He could now converse, feed himself, and walk 50 feet with his walker.