Hypotensive episodes on program hemodialysis during dialysis procedure: modern approach for diagnostics, prophylaxis and correction

Abstract

The study objective is to evaluate the effectiveness of different approaches to correction and prevention of arterial hypotension episodes in patients undergoing long-term hemodialysis (HD). Materials and methods. The study included 35patients undergoing long-term hemodialysis in the dialysis center. In all patients, automatic non-invasive measurement of arterial pressure (AP) was performed using a built-in option of the “artificial kidney” device. Prior to the study, all patients underwent clinical test with evaluation of “dry weight” and bioelectrical impedance analysis. Crossover design was used in the study: at the beginning, hypotensive episodes were corrected in all patients using the standard method (the first 4 hemodialysis procedures); then during the following 4 procedures in addition to standard methods a computer algorithm automatically controlling ultrafiltration rate using an automatic system of pressure control (ASPC) with constant AP monitoring (AP was measured prior to hemodialysis and after it and at least 1 time in the first 5 min of the procedure; from the 4h procedure onwards, intervals were determined by the algorithm automatically) was used. Values of mean AP during hemodialysis procedures for the whole monitoring period were analyzed. The duration of the study was 3 weeks for all patients. Results . Mean pre-dialysis systolic and diastolic AP in the patients for the standard approach was 124.6 ± 27.7 and 74.5 ± 21.1 mm Hg, post-dialysis AP was 114.4 ± 24.4 and 71.3 ± 16.3 mm Hg, respectively. For ASPC, pre-dialysis and post-dialysis AP was statistically significantly higher than for the standard approach: 133.2 ± 21.3 and 79.3 ± 15.8 mm Hg (p <0.001; p = 0.009), 125.7 ± 23.9 and 75.9 ± 18.3 mm Hg (p <0.001; p <0.001). Detailed analysis of intra-dialysis AP measured during the standard approach showed that it was 110.2 ± 17.3 and 68.3 ± 13.9 mm Hg. Using ASPC, intra-dialysis AP was significantly higher: 124 ± 20.5 and 75.9 ± 14.2 mm Hg (p = 0.03; p = 0.02). Mean AP was also higher: 82.5 ± 13.9 mm Hgfor the standard approach versus 91.5 ± 15.6 mm Hg (p = 0.01) for ASPC. The ultrafiltration rates were slightly higher without ASPC (8.2 ml/kg/hour vs. 7.9 ml/kg/hour). Therefore, it was shown that the use of ASPC in addition to standard methods of hypotension correction is effective and safe. There weren»t any significant differences in «hemodialysis-dose effectiveness» (Kt/V) in both groups; however, in the ASPC group target values of inorganic phosphorus in serum (for a dialysis patient) were reached which is one of the most important parameters of hemodialysis adequacy. Concentration of inorganic phosphorus for the ultrafiltration control algorithm was 1.5 mmol/l, for the standard dialysis program — 1.8 mmol/l which shows benefits of ASPC. This data didn»t reach statistical significance (p = 0.07) which likely can be attributed to a low number of observations. Conclusion . Intra-dialysis hypotension with high ultrafiltration rates is a frequent and potentially dangerous complication of hemodialysis which negatively affects patients» long-term prognosis mainly due to an increase in cardiovascular morbidity and mortality. A new method for prevention and correction of hypotension using ASPC allows to decrease ultrafiltration rate on time preventing a hypotensive episode, decreasing its rates and improving attainment of AP target values (both pre- and post-dialysis) as well as intra-dialysis variation during dialysis procedure.