The effect of diuretics upon the natrium and water homeostasis and renal bicarbonate metabolism is seldom monitored and utilized in the intensive care setting. The study deals in detail with the impact of diuretics upon the natrium and water homeostasis and their effects on acid-base balance. The administration of diuretics is enough invasive from the point of view of homeostatic monitoring with the aid of renal function tests. Therefore this study is the integral part of the monitoring system which is based on the use of the computer programme „KIDNEY“. The authors monitored effects of furosemide (18 patients), hydrochlorothiazide (8 patients), spironolactone (14 patients), acetazolamide (10 patients), amiclarane (4 patients) and manitol (8 patients) in critically ill patients using the computer programme working with 17 routinely monitored input values and 19 output parameters. The study attempts to clarify the exact mechanisms of the action of diuretics and to define the parameters available for monitoring and prediction of the effects of the selected agents. The broader and more correct administration of diuretics in homeostatic indications or the inclusion of some of the less used agents into the renoprotectione regimens could result from the study. This could be favoured by the acceptable costs of these agents.

        Key words: diuretics – intensive care – renal function tests – hypernatremia – hyponatremia – tonicity – osmolality – acidosis – alkalosis