Hemodynamic Parameters Changes in the Course of Hemodialysis Sessions in Patients With Intradialytic Hypertension

The number of patients with end stage renal disease (ESRD) is growing worldwide and nowadays hemodialysis (HD) treatment is the prevalent modality of renal replacement therapy. Paradoxically an increase of BP during or immediately after the HD sessions has been observed in some patients. This phenomenon is referred to as Intradialytic Hypertension (IDH). The focus will be on systolic BP increase ≥ 10 mmHg during or immediately after hemodialysis which results in post-dialysis hypertension BP above ≥130/80 mmHg. IDH affects up to 10-15% of hemodialysis patients. Patients with IDH have unfavorable outcomes; previous epidemiological data showed that IDH is associated with higher cardiovascular morbidity and mortality rates.

From the view of hemodynamic profile, peripheral resistance and cardiac output are the most important factors contributing to arterial blood pressure. The pathogenesis of IDH is likely to be multifactorial. Several mechanisms were proposed to be involved in the pathogenesis of this phenomenon.

Endothelial dysfunction, increased activity of the renin angiotensin aldosterone system (RAAS) and activation of the sympathetic nervous system had been shown to be involved in the increase of blood pressure during Hemodialysis in this group of patients.

None of these possible explanations or their inter-relationships has been studied in a controlled experimental setting and the actual physiological changes during hemodialysis in intradialytic hypertensive patients still remain unexplored.

The NICAS (Non-Invasive Cardiac System) device, used mainly for noninvasive cardiac diagnostic purposes, is substantially equivalent to the use of other hemodynamic evaluation tools, yet it is non-invasive and provides on-line data regarding the hemodynamic status of patients. Using this device, the hemodynamic changes during the HD session of IDH patients will be investigated.