Diuresis

Diuresis represents the urine volume which is formed in a human body for certain specific time. The concept of a daily urine – that is measurement of volume of the made urine in 24 hours, and also minute diuresis is most often used. The last size is used, as a rule, when studying function of kidneys by means of a clearance method.

Daily release of urine of the adult healthy person makes about 65-75% of volume of the drunk liquid in a day. To allocate all necessary products of a metabolism to a kidney not less than 500 ml therefore it is easy to count that the person needs to consume at least 800 ml of liquid a day that is the lower threshold indicator are necessary. At a normal water relationships which means the use of 1-2 liters of liquid the daily urine will make from 800 to 1500 ml, and the size of minute diuresis will make respectively 0,55-1 ml.

Various morbid conditions can influence release of urine, and is considerable. Distinguish an anury – release of urine less than 200 ml a day at a normal water relationships, an oligouriya – allocation urine no more than a halfliter a day, and also a polyuria – allocation to three liters of urine at the usual use of urine.

Also distinguish night and day diuresis. The ratio of day and night diuresis at the healthy person usually makes 3 to 1 or 4 to 1. The nocturia is pathology which develops at change of this ratio in favor of night diuresis.

Besides, diuresis is distinguished depending on the volume of urine and amount of the emitted active agents:

  • Water
  • Anti-diuresis
  • Osmotic diuresis

Large volume of urine at extremely low content of osmotic substances is characteristic of water diuresis. It represents release of gipoosmolyarny urine. At healthy people water diuresis can develop against consumption of large volume of liquid, at transition to a state of weightlessness, and also to a bed rest from a normal physical activity. Also it is characteristic at postencephalitic, psychogenic and primary polydipsia, in an end-stage of chronic diseases of kidneys, an alcoholism, a hypercalcemia, a hypopotassemia, a renal not diabetes mellitus, and also in a phase of a convergence of hypostases.

For anti-diuresis the small volume of urine together with high concentration of active osmotic agents is inherent.

Osmotic diuresis is an allocation of a large amount of urine because of the raised excretion of active agents. It usually develops because of excessive loading of department of nephron active agents exogenous (simple sugar, a mannitol) and an endogenous origin (bicarbonate, urea, glucose). When in a gleam of tubules availability of active agents in concentration which exceed ability to their reabsorption is observed, and also exogenous nereabsorbiruyemy substances there is accelerated liquid current. Thus, large volume of urine at high concentration is allocated in it osmotic active agents. Content of sodium, for example, makes 50-70 mmol/l. As a rule, such state can develop at use of osmotic diuretics, a chronic renal failure, a diabetes mellitus.

Section: D