A 75-year-old female presented with increasing drowsiness and no other specific features. Past medical history included the antiphospholipid syndrome, three episodes of myocardial infarction, left ischaemic leg, epilepsy, hypothyroidism and splenectomy. Medications included warfarin. Examination showed pulse 70/min, blood pressure 120/60 mmHg, crepitations at the left lung base, a Glasgow Coma Scale 14/15. Investigations revealed serum sodium 117 mmol/l, urea 8.8 mmol/l, serum osmolality 269 mOsmol/kg, urine osmolality 493 mOsmol/kg, urine sodium 49 mmol/l. Haemoglobin was 13.2 g/dl, initial INR 7.5. Chest X-ray showed consolidation at the left lung base. CT brain scan was unremarkable. Short synacthen test showed serum cortisol 585 nmol/l (basal) and 482 nmol/l (stimulated).
The patient was treated with intravenous antibiotics and fluid restriction with improvement in her serum sodium (128 mmol/l). The short synacthen test repeated after 1 week showed hypoadrenalism (peak cortisol 149 nmol/l). Serum ACTH was 65 ng/l (050), FT4 19.8 pmol/l (11.522.7), TSH 0.51 mIU/l (0.355.50). CT showed bilateral bulky adrenals compatible with adrenal infarction with some haemorrhage. A repeat scan after three months showed significant resolution. Investigations for antiphospholipid syndrome were repeated and showed Anti-cardiolipin IgG 1902.0 GPL U/ml (09.9), Anti-cardiolipin IgM 119.0 MPL U/ml (09.9), lupus anticoagulant positive. The patient was treated with hydrocortisone and fludrocortisone and her condition improved. Her electrolytes returned to normal (serum sodium 133 mmol/l, potassium 4.7 mmol/l).
This lady therefore had evidence of SIADH which was probably secondary to respiratory infection but also had acute adrenal failure due to infarction associated with the antiphospholipid syndrome. This case illustrated the importance of considering adrenal failure due to infarction in patients with antiphospholipid syndrome who present non-specifically unwell, even when there is evidence of infection.