Osmotically volumetric urine index in early recognition and evaluation of the central diabetes insipidus correction efficiency

Purpose of the work: to develop an information criterion for early recognition and evaluation of the homeostasis correction efficiency in central diabetes insipidus. Materials and methods. 48 neurosurgical patients who underwent traumatic brain injury (21), surgery for a brain tumor (14) and stroke (13), whose course of the disease was complicated by central diabetes insipidus, have been examined. The diuresis rate and urine density (refractometrically) were studied in each of its portions excreted out of the body within an hour. According to the indicator of osmotic density and the range of urine output, an information criterion for the diagnosis of diabetes insipidus and the dynamics of its course was developed – the osmotically volumetric urine index (OVUI). Results and discussion. With physiological water input, 0.8-1.0 ml∙kg-1of urine is usually excreted from the human body within an hour. Concurrently, its specific gravity (urine density, UD) is 1012-1025. In 12 patients of the comparison group without diabetes insipidus, the OVUI index was 8.0-12.0. Central diabetes insipidus is characterized by significant homeostasis disorders: blood hypohydration and hyperosmolarity due to violation of hypothalamic-pituitary regulation of antidiuretic hormone secretion. In these conditions the osmotically volumetric urine index decreases to indicators ˂ 1.0. The criterion for the intensive therapy efficiency for homeostasis disorders in diabetes insipidus is OVUI increase above 1.0. The article presents a clinical case of timely recognition and successful correction of homeostasis in a patient with traumatic brain injury complicated by central diabetes insipidus.  Conclusions. The osmotically volumetric urine index – is an indicator that allows diagnosing diabetes insipidus in its early manifestations and timely preventing a violation of homeostasis. With the norm of OVUI at 8.0-12.0, its decrease to ˂ 1.0 indicates the presence of diabetes insipidus in the patient. Timely and adequate correction of disorders of hydration, blood osmolarity and the use of desmopressin lead to the OVUI normalization, which is a dynamic marker of the efficiency of intensive therapy of diabetes insipidus. The simplicity of the study (the possibility of carrying it out directly at the patient’s bedside), as well as the informativeness of the OVUI diagnostic and prognostic values deserve to be used in clinical practice.