An integrative physiological approach to polyuria and hyponatraemia: a 'double-take' on the diagnosis and therapy in a patient with schizophrenia.
A patient with a history of schizophrenia was brought to the emergency department with extensive self-inflicted soft tissue injuries. Primary polydipsia was evident on admission, because he had a maximally dilute urine, a urine flow rate of 10 ml/min, and hyponatraemia (100 mmol/l). During an imaginary consultation with Professor McCance in which he applied basic principles of integrative physiology and a deductive analysis in quantitative terms, other reasons for the polyuric state were considered. Moreover, based on the very low value for the concentration of urea in plasma (< 0.7 mmol/l, BUN 1 mg /dl), the goals of therapy to prevent osmotic demyelination became evident. Applying this simple approach, a more comprehensive and accurate differential diagnosis, and a plan for therapy to avoid serious complications was compiled.
Edoute
Y
Y
Department of Internal Medicine C, Rambam Medical Center, Faculty of Medicine, Technion Israel Institute of Technology, Haifa, Israel.
Davids
M R
MR
Johnston
C
C
Halperin
M L
ML
D000328:Adult; D003919:Diabetes Insipidus / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004231:Diuresis; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D011141:Polyuria / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D012076:Renal Agents / Q000627:therapeutic use; D012559:Schizophrenia / Q000150:complications*; D014508:Urea / Q000097:blood; D014667:Vasopressins / Q000627:therapeutic use
D012076:Renal Agents; D014667:Vasopressins; D014508:Urea