Stauss Mary, Sherman Beth, Pugh Lorene, Parone Dominic, Looby-Rodriguez Karen, Bell Annette, Reed Carole-Rae
Camden, NJ.
Camden, NJ.
J Emerg Nurs. 2012 Jan;38(1):15-21. doi: 10.1016/j.jen.2010.08.011. Epub 2010 Oct 2.
Hemolysis of blood samples creates significant delays in the treatment and disposition of patients in the emergency department. The purpose of this study was to compare the hemolysis rates of coagulation blood samples obtained during insertion of an intravenous (IV) catheter without (group 1) or with (group 2) extension tubing connected to the IV catheter hub. A secondary purpose of this study was to determine whether the investigators could predict whether a coagulation sample was hemolyzed based on visual observation during the specimen withdrawal process.
A prospective, 2-group randomized comparative design was used to determine which method of blood collection for coagulation specimens provided the lowest hemolysis rate. This study was conducted in an urban level I emergency department averaging 58,000 visits per year. The sample consisted of 121 adult ED patients randomly assigned to 1 of the 2 groups. Data collectors were trained in the 2 methods of coagulation sample collection and followed a strict protocol. The clinical laboratory used a standardized color-coded scale to determine hemolysis.
Pearson χ(2) analysis was used to test for differences between all nominal variables. The level of significance for all tests was P < .05. There was no significant difference in hemolysis rates between the groups by use of χ(2) analysis (P = .84). Nurses were significantly more likely to predict that a sample was hemolyzed when it was not and to think that it was not hemolyzed when in fact it was (P < .001).
High hemolysis rates occurred equally when coagulation blood samples were drawn via a peripheral IV catheter either at the hub or through extension tubing. Emergency nurse investigators could not accurately predict by visualization whether a coagulation sample was hemolyzed at the time of blood withdrawal. Venipuncture as the preferred method of blood draw is an industry recommendation. This method has been shown in prior experimental studies to reduce hemolysis rates to less than 4%. Therefore, if hemolysis rates are a concern, one should consider obtaining blood whenever possible through a venipuncture rather than through an IV catheter. Replication studies are needed to determine whether the findings of this study can be generalized to the larger population.
血液样本的溶血会显著延迟急诊科患者的治疗和处置。本研究的目的是比较在插入静脉（IV）导管期间采集的凝血血液样本的溶血率，其中一组（第1组）静脉导管接口处未连接延长管，另一组（第2组）连接了延长管。本研究的第二个目的是确定研究人员能否在样本采集过程中通过视觉观察预测凝血样本是否发生溶血。
采用前瞻性、两组随机对照设计，以确定哪种凝血样本采集方法的溶血率最低。本研究在一家每年平均接诊58000例患者的城市一级急诊科进行。样本包括121例成年急诊科患者，随机分为两组。数据收集者接受了两种凝血样本采集方法的培训，并遵循严格的方案。临床实验室使用标准化的颜色编码量表来确定溶血情况。
采用Pearson χ²分析检验所有名义变量之间的差异。所有检验的显著性水平为P < .05。通过χ²分析，两组之间的溶血率没有显著差异（P = .84）。护士更有可能在样本未溶血时预测其溶血，而在样本实际溶血时认为未溶血（P < .001）。
通过外周静脉导管在接口处或通过延长管采集凝血血液样本时，高溶血率的发生情况相同。急诊护士研究人员无法通过视觉观察准确预测采血时凝血样本是否溶血。静脉穿刺作为首选的采血方法是行业推荐。先前的实验研究表明，这种方法可将溶血率降低至4%以下。因此，如果担心溶血率，应尽可能通过静脉穿刺而非静脉导管获取血液。需要进行重复研究以确定本研究结果是否可推广到更广泛的人群。
