An 80 year old woman is brought in semi-conscious. She had been lethargic for the last several weeks and was unable to get out of bed yesterday. She has no known comorbidities. A full blood count, c-reactive protein, capillary blood sugar, chest x-ray and CT brain are normal. Her ECG shows sinus bradycardia with low voltage complexes, while cardiac troponins are not elevated.
Na+ 125 mEq/l K+ 3.9 mEq/l Cl- 103 mEq/l
TSH: 100 mIU/l (range: 0.4 to 4 mIU/l) Free T3: undetectable Free T4: undetectable
PaO2: 68 mmHg (range: 75 - 100) PCO2: 50 mmHg (range: 36 - 44) HCO3: 27 mmol/l (range: 22 - 26) pH: 7.32 (range: 7.35 - 7.45)
Pus cells: field full/hpf RBC: 5 - 6/hpf Gram stain: Gram negative bacilli