Mihaela-Elisabeta Stafie 1, I. Al. Checherită 1, A. Niculae 1, Gabriela Lupuşoru 1, Cristiana David 1, Al. Ciocâlteu 1
1 Nephrology Department, “Sf. Ioan” Emergency Clinical Hospital, “Carol Davila”, University of Medicine and Pharmacy, Bucharest
Abstract
Background Intradialytic hypotension continues to be a major problem in hemodialysis treatment today, despite technical improvements. Its origin is still a subject of extensive research. The aim of the study was to identify the cause of intradialytic hypotension, measuring hemodynamic parameters during a hemodialysis session. This strategy provides the opportunity of classifying the patients into different risk categories and may lead to an individualized dialysis protocol. Methods The variations in arterial blood pressure, cardiac stroke volume, heart rate, cardiac output and systemic vascular resistance were monitored during a hemodialysis session in sixty-two patients on chronic intermittent hemodialysis. Results Seventeen patients experienced an episode of intradialytic hypotension. Based on the predominance of systemic vascular resistance (SVR) or stroke volume (SV) decrease at the time of hypotension, two groups could be differentiated. Six patients showed a fall in SVR (HID_svr group) whereas eleven patients showed a more pronounced decrease in cardiac output, caused by a decline in stroke volume. In the HID_sv group, Pearson’s correlation revealed a predominant relationship between cardiac output variations and mean arterial pressure variations (R=0.59, p=0.001). No correlation was found between systemic vascular resistance and mean arterial pressure variations in this group. In the HID_svr group, the mean arterial pressure variations showed a strong correlation with systemic vascular resistance variations (R=0.71, p=0.002) and a poor correlation with stroke volume (R=0.21, p=0.001) and cardiac output variations (R=0.11, p=0.0012). Conclusion Based on the hemodynamic response, intradialytic hypotension is due to cardiac filling failure caused by hypovolemia in one group, while in another group a fall in systemic vascular resistance, independent of cardiac function, is the cause of this complication. Different preventive strategies are proposed for the different subgroups.