Continuous analysis of urine contents in intensive care unit

Research Project

Project/Area Number	14571458
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Anesthesiology/Resuscitation studies
Research Institution	Kyoto Prefectural University of Medicine
Principal Investigator	TANAKA Yoshifumi Kyoto Prefectural University of Medicine, Anesthesiology, Professor, 医学研究科, 教授 (50079935)
Project Period (FY)	2002 – 2003
Project Status	Completed (Fiscal Year 2003)
Budget Amount *help	¥2,700,000 (Direct Cost: ¥2,700,000) Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
Keywords	Urinary volume / Urinary osmolarity / Sodium concentration / Potassium concentrations / natriuretic condition / isosmotic condition / Urea / Creatinine / 集中治療 / 腎機能連続監視 / 浸透圧 / 塩素イオン / カリウムイオン / マグネシウムイオン / 尿量監視
Research Abstract	Compared with the attention to the concentration of electrolytes in blood, that of them in urine was minimized because of large variety in normal range. Urinary output and concentrations of electrolytes or other substances are strongly affected by the circulatory conditions or hormonal conditions. We devised an automatic and continuous measuring system of urinary output and concentration of each solute (Sodium, Potassium, Urea, Creatinine) and investigated of them in intensive care unit. The results of the investigation was quite interesting one. First of all, the relationship of the urinary volume and osmolarity of it was in inverse proportion. As the concentration of urea or creatinine increases, the osmolarity of urine was increased. However the relationship of sodium and potassium concentrations versus osmolarity was different and complicated. In the isosmotic urinary situation, the sodium and potassium concentrations depicted precisely 110 mEq/L and 10 mEq/L respectively. Then as the osmolarity in urine increases the concentration of sodium was decreased the minimized to 60 mEq/L at 560 mosmol, then the concentration of it was increased proportionally. The potassium concentration in urine was increased proportionally until to the 560 mosmol in urine osmolarity and measured almost 100 mEq/L of the concentration, after then the value was decreased. Those results seems to be quite natural phenomenon. We obtain 2 ml/kg/hour of fluid and 1 ml/kg/hour of urination in normal situation. Hence, two times of isosmotic condition of urinary output might be best suitable situation for sodium reabsorption and potassium secretion. These results also explains why hypokalemia will occur in natriuretic condition.