CASE REPORT
Mr M.R, 57 years-old, was admitted to the intensive care unit of the emergency room for apyretic loss of consciousness. He had a history of schizophrenic disorders for which he was treated with Olanzapine 10mg/day. His family reported that the symptoms were poorly controlled pushing the patient to increase the daily dosage of his medication by himself.
The day of admission, the patient was found unconscious by his family, prompting a visit to the emergency room.
On admission, his Glasgow consciousness score was 6, pupils were equal and reactive, with no signs of focalization or extrapyramidal syndrome and no signs of seizures.
He was polypneic at 34 cpm, his saturation was 80% on room air with paradoxical breathing and respiratory pauses. Pulmonary auscultation was unremarkable.
Hemodynamically, BP was 115/70 mmHg, HR 110 bpm, RT < 3sec. Capillary glycemia was 2g/l, and the temperature 37.3°. His diuresis was preserved and urine was slightly concentrated.
After conditioning, the patient was intubated and then sedated, with a cerebral CT scan that came back normal, and a biological workup that came back in favour of hyponatremia at 106 mEq/l and rhabdomyolysis with CPK at 19829 UI/l, LDH at 2254 UI/l and concomitant hyperkaliemia at 6.9 meq/l.
Management consisted of correction of the natremia and forced alkaline diuresis.
The rest of the work-up showed a urinary osmolarity of 638 mOsm with a natriuresis of 190 mEq/l and a blood osmolarity of 219 mOsm and thus met all the major criteria for inappropriate secretion of anti-diuretic hormone (ISADH). The etiological investigation came back negative, and the patient was diagnosed with SIADH with rhabdomyolysis secondary to Olanzapine.
The patient was subsequently transferred to a medical intensive care unit for further management. The evolution was marked by a complete awakening of the patient, extubation on day 6 of his admission, after correction of the natremia (146 mEq/l), decrease in the markers of rhabdomyolysis from day 3 (CPK: 1681 UI/l, LDH: 503 UI/l) and normal kaliemia.