Prichard Jack S, French John S, Alvar Nestor
Shannon Medical Center, San Angelo, Texas, USA.
J Extra Corpor Technol. 2006 Jun;38(2):128-33.
As a small portable instrument, which can be dedicated to the perfusionist, the Radiometer model ABL-77 point-of-care blood gas, electrolyte, and hematocrit analyzer has come to provide an alternative to in-line monitoring of such parameters. This is not to say that it can necessarily replace the utility of in-line monitoring. However, point of care instruments, such as the ABL-77, can provide faster results than a more remote lab. This study was done as part of an ongoing quality assurance program in conjunction with the main lab department to maintain accreditation. The hypothesis being tested is that during cardiopulmonary bypass (CPB) the ABL-77 is in agreement with alternative instruments used outside the cardiovascular operating room. With the appropriate institutional approval, a total of 20 blood samples were randomly gathered among five patients after initiation of CPB. This was done over a five-day period for pH, pCO2, pO2, potassium, sodium, and hematocrit determinations. Analysis results from the ABL-77 were compared to those made by three other bench top models. These included a Radiometer model ABL-720 analyzer, a Dale Dimension model RxL analyzer, and a Beckerman model LH 750 Coulter Counter. A statistically significant difference is demonstrated for all parameters when each of these instruments is compared to the ABL-77. However, the observed mean differences are only judged to be clinically significant in the case of hematocrit. The ABL-77 is found to demonstrate a negative bias with respect to the different methodologies used by the ABL-720 and the Coulter Counter. This bias may be due to the hemodilution of plasma with crystalloid solution during CPB. This causes error in hematocrit results as the methodology of many point of care instruments is based on the electrical conductivity of whole blood. This may be corrected by using a relationship determined from linear regression analysis. This error adjustment has been implemented as part of a concerted blood conservation effort. Otherwise, the ABL-77 has been found to be reliable and consistent for point of care blood analysis.
作为一款可专门供灌注师使用的小型便携式仪器，雷度米特ABL-77即时检测血气、电解质及血细胞比容分析仪为在线监测这些参数提供了一种替代方案。但这并非意味着它必定能取代在线监测的作用。然而，像ABL-77这样的即时检测仪器能比距离更远的实验室更快地给出结果。本研究是作为与主要实验室部门联合开展的一项持续质量保证计划的一部分进行的，目的是维持认证。所检验的假设是，在体外循环（CPB）期间，ABL-77与心血管手术室之外使用的其他仪器结果一致。经适当的机构批准，在CPB开始后，从五名患者中随机采集了总共20份血样。这是在五天时间内针对pH值、二氧化碳分压（pCO2）、氧分压（pO2）、钾、钠和血细胞比容的测定进行的。将ABL-77的分析结果与其他三款台式仪器的结果进行了比较。这三款仪器包括雷度米特ABL-720分析仪、德灵Dimension RxL分析仪和贝克曼LH 750库尔特计数器。当将这些仪器中的每一款与ABL-77进行比较时，所有参数均显示出统计学上的显著差异。然而，观察到的平均差异仅在血细胞比容方面被判定具有临床意义。发现ABL-77相对于ABL-720和库尔特计数器所采用的不同方法存在负偏差。这种偏差可能是由于CPB期间晶体溶液对血浆的血液稀释所致。这会导致血细胞比容结果出现误差，因为许多即时检测仪器的方法是基于全血的电导率。这可以通过使用线性回归分析确定的关系来校正。这种误差调整已作为协同血液保护措施的一部分得以实施。否则，已发现ABL-77在即时检测血液分析方面可靠且一致。
