Object of the study: pyelonephritis (PN) in children. Purpose of the study: perfection of the diagnosis and prognosis of PN course in children on the basis of revealing peculiarities in the relationships of the central, renal haemodynamics and neurohu-moral mechanisms of its control. Methods of the study: clinical, laboratory (determination of the level of angiotensin I, angiotensin II, hydrocortisone, nitrogen ox-ide in the blood serum), instrumental (echocardiography, ultrasonographic examination of the kidneys in Doppler mode). Practical significance: on the basis of the conducted research with use of modern instrumental and laboratory methods, the state of the central and renal haemodynamics in children with PN was charac-terized depending upon the form, course of PN and duration of the disease, as well as their relationships with the state of the rennin-angiotensin system, the level of glucocorticoids and nitrogen oxide. The conducted research resulted in the proof that it was necessary to supplement a complex of the clinical-laboratory examination of children, ill with PN, with Doppler ultrasonographic examination of the kidneys, the study of the indices of the rennin-angiotensin system, hydrocortisone and nitrogen oxide metabolites in order to increase the level of diagnosis and prognosis for the course of PN. The importance of studying the levels of NO2-, NO3-, hy-drocortisone in the blood serum was scientifically grounded as an additional significant criterion of the degree of activity and severity of PN course. A number of highly informative prognosticating criteria of possible progression of PN were determined and grounded for practical health protection: resistance index, systolic-diastolic proportion, minimum rate of diastolic blood flow in the renal artery, the level of angiotensin and nitrogen oxide in the blood serum. Novelty of the obtained results: for the first time, it was revealed that in children with PN, even before the latter was accompanied by chronic renal insufficiency, there were compensatory-adaptive reconstructions in the central and renal blood flow, caused by acti-vation of the rennin-angiotensin system and depression of nitrogen oxide synthesis, which were characterized by the formation of the hypokinetic type of haemodynamics in 42.2 % of patients, and dis-turbances of the renal blood flow in 65.1 % of cases. For the first time, criteria for assessing PN activity degree by the level of nitrogen oxide and hydrocortisone were scientificcally grounded and suggested (A way for diagnosing pyelonephritis activity degree in children: Pat. 28610 UA /Yu.V. Odinets, Yu.I. Sharkovskaya. Cl. №u200711042. Appl. 5.10.2007. Publ. 10.12.2007). It was proved that the most significant in the diagnosis of PN progression were a high level of angiotensin II, a low level of nitrogen oxide in the blood serum against a background of the vasospastic variant of the renal blood flow (a higher resistance index and a lower mini-mum diastolic rate of the blood flow). Introduction: the main results of theconducted researches were introduced into the work of the Nephrology Department of Kharkiv City Children’s Clinical Hospital No. 16, Evpatoria Regional Children’s Clinical Hospital, First Children’s Clinical Union of the City of Simferopol. Sphere (area) of application: medicine, paediatrics.
