目的 不同排液理念和排液方式在透析器与血液净化管路内残存的液体量存在差异，本研究探讨血液透析患者治疗结束后不同排液方式对透析器与血液净化管路内残存的液体(废液)的排空效果，探索最佳安全有效的排液方式，以减少对环境的污染和感染的发生。方法  选取200例维持性血液透析患者透析后的透析器与血液净化管路；实验组150例，选用以负压和正压(血泵)排液方式为代表的透析机厂商指导排液方法，分为3组，每组50例，分别使用100ml/min、200ml/min、300ml/min的血泵转速提供不同的正压。对照组50例选用以负压加重力排液方式为代表的透析机厂商指导的排液法；进行实验组与对照组排液过程中跨膜压、排液后透析器与血液净化管路废液残存重量、排液时间比较，实验组上述指标亦进行组间比较。 结果 与对照组相比，实验组较对照组排空时间短(泵速200ml/min：Z=6.598，P＜0.001；泵速300ml/min：Z=10.920，P＜0.001)，排空后液体残存量低于对照组(泵速100ml/min：Z=8.202,P＜0.001；泵速200ml/min：Z=8.888,P＜0.001；泵速300ml/min：Z =7.894,P＜0.001)。对照组排液过程中跨膜压(transmembrane pressure，TMP)均在厂家标注的透析器破膜安全值范围内，并且压力低于实验组(泵速100ml/min：Z =-3.965，P＜0.001；泵速200ml/min：Z =-6.945，P＜0.001；泵速300ml/min：Z =-9.498,P＜0.001)。实验组组间比较，排液泵速300ml/min组跨膜压瞬时值会高于透析器制造商使用说明书的最大安全值500mmHg，有10%破膜的风险。 排液血泵转速200ml/min时TMP均在安全范围内，且排液时间短于血泵转速100ml/min组，为最安全高效的排液泵速(1.48min比2.21min，Z=6.359，P＜0.001)。 结论 以负压和正压(血泵)排液方式，排液泵速控制在不破膜的基础上排液时间及废液残存的量都优于以负压加重力排液式的透析机。

Objective   The amount of liquid remaining in the dialyzer and blood purification pipeline is variable with different drainage methods. This study investigated the evacuation effect of different drainage methods on residual waste volume in the dialyzer and blood purification pipeline after the treatment of hemodialysis patients, and explored the safest and effective drainage method to reduce the risks of environmental pollution and infection.  Methods  The dialyzers and blood purification tubes after hemodialysis of 200 cases were selected. In the experimental group, the dialyzers with the drainage method of negative pressure plus positive pressure (blood pump) guided by the manufacturers were used for 150 cases, who were then divided into 3 subgroups (50/each subgroup); positive pressures were provided by the blood pump of 100ml/min, 200ml/min and 300ml/min for the 3 subgroups respectively. In the control group, the dialyzers with the drainage method of negative pressure plus gravity guided by the manufacturers were used for 50 cases. The transmembrane pressure during drainage, drainage time, and residual waste volume (gram) in dialyzer and blood purification pipeline after drainage were compared between experimental group and control group and among the 3 subgroups in the experimental group.  Results   In the experimental group, the evacuation time was shorter (blood pump speed 200ml/min: 1.48 vs. 2.22 min, Z=6.598, P＜0.001; 300ml/min: 0.49 vs. 2.22 min,            Z=10.920, P＜0.001), and the residual waste volume after drainage was lower (blood pump speed 100ml/min: 90.9 vs. 136.4g, Z=8.202, P＜0.001; 200ml/min: 88.9 vs. 136.4 g, Z=8.888, P＜0.001; 300ml/min: 91.9 vs. 136.4 g, Z=7.894, P＜0.001), as compared with those in the control group. In the control group, the transmembrane pressure during drainage was within the safety range not causing membrane rupture set by the manufacturers, and the transmembrane pressure was lower than that in the experimental group (blood pump speed 100ml/min: 359.5 vs. 457.5 mmHg, Z=-3.965, P＜0.001; 200ml/min: 359.5 vs. 476.0 mmHg, Z=-6.945, P＜0.001; 300ml/min: 359.5 vs. 487.5 mmHg, Z=-9.498, P＜0.001). In the subgroup of blood pump speed 300ml/min in the experimental group, the instant transmembrane pressure exceeded the maximal safety value of 500mmHg set by the manufacturers, leading 10% risk of membrane rupture; in the subgroup of blood pump speed 200ml/min, the transmembrane pressure during drainage was within the safety range, and the evacuation time was shorter than that in the 100m/min subgroup, being the safest and efficient drainage pump speed (1.48 vs. 2.21min, Z=6.359, P＜0.001).  Conclusion  Compared with the dialyzers using negative pressure and gravity as the drainage method, the dialyzers using negative pressure and positive pressure (blood pump) as the drainage method had the advantages of shorter evacuation time and lower residual waste volume when the drainage pump speed was set within the pressure not breaking the membrane.