Intensive Care Unit, Hospital Universitario de Móstoles, Móstoles, Madrid, Spain.
Faculty of Nursing, Physiotherapy and Podology, Universidad Complutense de Madrid, Madrid, Spain.
Nurs Crit Care. 2017 Sep;22(5):298-304. doi: 10.1111/nicc.12220. Epub 2015 Oct 21.
Intensive care patients require a high frequency of blood testing, which results in a significant amount of blood loss. When blood is obtained from a central venous catheter (CVC), a large volume is usually discarded to obtain an unaltered sample for testing.
To determine the reliability of complete blood test results in blood samples obtained from the proximal lumen of a triple-lumen CVC using a 2-mL discard volume DESIGN: Observational study with the prospective collection of data METHODS: The subjects enrolled were all patients with a subclavian triple-lumen CVC, older than 17 years and consecutively admitted to intensive care over a 2-year period. In each of the 54 participants, one blood sample was drawn from the proximal lumen of the catheter, discarding 1·61 mL of blood plus 0·39 mL of catheter deadspace (2 mL) and without interrupting infusion in the middle and distal lumens. A second sample was then obtained by direct venous puncture. The reliability of blood test results was determined by comparing sets of variables recorded for the two sampling methods through intraclass correlation coefficients in the Bland-Altman method.
Inter-method reliability for the variables examined was excellent, >0·75; range (0·868-0·998). Mean differences between the two sample types for the variables most often determined in critically ill patients were leukocytes: 0·200 × 10 /µL, 95% confidence interval (CI) (0·025 to 0·375); erythrocytes: 0·045 × 10 /uL, 95% CI (-0·003 to 0·094); sodium: 0·074 mEq/L, 95% CI (-0·369 to 0·517); potassium: -0·002mEq/L, 95% CI (-0·065 to 0·061) and glucose: 2·426 mg/dL, 95% CI (0·498-4·354).
The sampling method proposed minimizes blood loss while offering reliable blood test results.
The main benefit of the method proposed is reduced blood loss, improving the care of a critically ill patient.
重症监护患者需要频繁进行血液检测，这会导致大量失血。当从中心静脉导管（CVC）获取血液时，通常会丢弃大量血液以获得用于检测的未改变样本。
确定使用 2 毫升丢弃量从三腔 CVC 近端腔获得的全血细胞检测结果的可靠性。
前瞻性数据收集的观察性研究。
所有研究对象均为锁骨下三腔 CVC 的患者，年龄大于 17 岁，在 2 年内连续入住重症监护病房。在 54 名参与者中的每一位中，从导管的近端腔中抽取一份血样，丢弃 1.61 毫升血液和 0.39 毫升导管死腔（2 毫升），而不中断中间和远端腔的输液。然后通过直接静脉穿刺获取第二份样本。通过 Bland-Altman 方法中的组内相关系数比较两种采样方法记录的变量集来确定血液检测结果的可靠性。
所检查变量的两种方法之间的可靠性很高，>0.75；范围（0.868-0.998）。对于在重症患者中最常确定的变量，两种样本类型之间的平均差异为白细胞：0.200×10 /µL，95%置信区间（CI）（0.025 至 0.375）；红细胞：0.045×10 /uL，95% CI（-0.003 至 0.094）；钠：0.074 mEq/L，95% CI（-0.369 至 0.517）；钾：-0.002 mEq/L，95% CI（-0.065 至 0.061）和葡萄糖：2.426 mg/dL，95% CI（0.498-4.354）。
所提出的采样方法可最大程度地减少血液丢失，同时提供可靠的血液检测结果。
该方法的主要优点是减少血液丢失，从而改善重症患者的护理。
