Donauer Johannes, Schweiger Christoph, Rumberger Brigitta, Krumme Bernd, Böhler Joachim
Department of Nephrology, University Hospital Freiburg, Germany.
Nephrol Dial Transplant. 2003 Aug;18(8):1616-22. doi: 10.1093/ndt/gfg206.
This study compares the effect of online-haemodiafiltration (o-HDF, post-dilution mode) with conventional haemodialysis (HD) and 'temperature-controlled' HD (Temp-HD) on the haemodynamic stability of hypotension-prone patients.
Seventeen patients with a history of frequent hypotensive episodes during dialysis sessions were studied, each patient serving as his or her own control. The first 25 HD treatments in comparison with 25 o-HDF sessions were evaluated using identical dialysate temperature. In the second part of the study, o-HDF (n = 25) was compared with Temp-HD (n = 25). In the latter method, the temperature of the dialysate was adjusted to result in identical energy transfer rates to those in the corresponding o-HDF. The number of hypotensive episodes, blood temperature and blood volume regulation were assessed.
Symptomatic hypotension was much more frequent during HD (40%) than during o-HDF (4%) (P < 0.001). During o-HDF, an enhanced energy loss within the extracorporeal system occurred (o-HDF, 16.6 +/- 4.0 W; HD, 5.4 +/- 5.1 W; P < 0.0001), despite identical temperature settings for dialysate and substitution fluid. As a result, the blood returning to the patient was cooler during o-HDF than during HD (o-HDF 35 +/- 0.2 degrees C vs HD 36.5 +/- 0.3 degrees C; P < 0.0001). In o-HDF, even in the patients' circulation, the mean blood temperature was lower (o-HDF 36.7 +/- 0.2 degrees C vs HD 36.9 +/- 0.3 degrees C; P < 0.0001) and blood volume was significantly more reduced (o-HDF, 91.8 +/- 3.1%; HD, 94.0 +/- 3.2%; P < 0.05). Energy transfer rates and blood temperature did not differ significantly between o-HDF and Temp-HD. The rate of hypotensive episodes was low and not different between o-HDF (4%) and Temp-HD (4%). Neither was there any significant difference in blood volume reduction.
O-HDF showed a significant reduction of hypotensive episodes compared with HD. Surprisingly, o-HDF resulted in cooling of the blood via enhanced thermal energy losses within the extracorporeal system, despite use of replacement fluid prepared from pre-warmed dialysate. The incidence of symptomatic hypotension was reduced to that of o-HDF by using cooler Temp-HD. Thus, unexpected blood cooling appears to be the main blood pressure-stabilizing factor in o-HDF.
本研究比较了在线血液透析滤过（o-HDF，后置稀释模式）与传统血液透析（HD）以及“温度控制”血液透析（Temp-HD）对低血压倾向患者血流动力学稳定性的影响。
对17例在透析过程中频繁出现低血压发作史的患者进行研究，每位患者作为自身对照。使用相同的透析液温度评估前25次HD治疗与25次o-HDF治疗。在研究的第二部分，将o-HDF（n = 25）与Temp-HD（n = 25）进行比较。在后者方法中，调整透析液温度以使其能量传递速率与相应的o-HDF相同。评估低血压发作次数、血液温度和血容量调节情况。
HD期间症状性低血压的发生频率（40%）远高于o-HDF期间（4%）（P < 0.001）。在o-HDF期间，尽管透析液和置换液的温度设置相同，但体外系统内的能量损失增加（o-HDF，16.6 +/- 4.0瓦；HD，5.4 +/- 5.1瓦；P < 0.0001）。结果，o-HDF期间返回患者体内的血液比HD期间更冷（o-HDF 35 +/- 0.2℃对HD 36.5 +/- 0.3℃；P < 0.0001）。在o-HDF中，即使在患者循环中，平均血液温度也较低（o-HDF 36.7 +/- 0.2℃对HD 36.9 +/- 0.3℃；P < 0.0001），且血容量显著减少更多（o-HDF，91.8 +/- 3.1%；HD，94.0 +/- 3.2%；P < 0.05）。o-HDF与Temp-HD之间的能量传递速率和血液温度无显著差异。低血压发作率较低，o-HDF（4%）与Temp-HD（4%）之间无差异。血容量减少方面也无显著差异。
与HD相比，o-HDF显示出低血压发作显著减少。令人惊讶的是，尽管使用了由预温透析液制备的置换液，但o-HDF通过体外系统内增强的热能损失导致血液冷却。使用较冷的Temp-HD可将症状性低血压的发生率降低至o-HDF的水平。因此，意外的血液冷却似乎是o-HDF中主要的血压稳定因素。
