Abstract
Objective. To analyse hyponatraemia symptoms in psychiatric inpatients, with the focus on factors adversely affecting the course of the condition. Hyponatreamia may develop in the course of mental disorders and somatic diseases. Early symptoms may either suggest the onset of mental disorders or modify the clinical pattern of those already present. An increasing hyponatraemia may lead to an irreversible brain damage and death. Too rapid sodium supplementation may be also life threatening.
Case. In the first case hyponatraemia resulted in an irreversible brain damage and the patient's death. He suffered from chronic schizophrenia and unrecognized polydipsia, and was treated with haloperidol. The second patient with schizoaffective psychosis and unrecognized adrenal tumours developed hyponatraemia in the course of an infection of upper airways, and his death was due to septicaemia. In the third case mental disorders were caused by hyponatraemia in the course of a paraneoplastic syndrome with ecotopic ADH secretion by a latent microcellular carcinoma of the left lung. In this case psychiatric symptoms and metabolic disorders preceded by a few months both the clinical and radiological manifestation of the neoplastic process.
Commentary. Long-term schizophrenia and persistent, chronic psychotic symptoms increase the risk of polydipsia with overhydration and hyponatraemia. In such cases the amount of ingested liquids, urine specific weight and natraemia should be controlled. There is a need for more accessible specialist medical services for patients living in a local community, who suffer from chronic mental disorders and are helpless. The first episode of hyponatraemia in the course of mental disorders always requires a thorough diagnosis of the patient's physical state.