Peixoto A J, Gray T A, Crowley S T
Sections of General Internal Medicine and Nephrology, Yale University School of Medicine, New Haven and Veterans Administration Connecticut Health Care System, West Haven Campus, West Haven, Connecticut, USA.
Blood Press Monit. 1999 Oct;4(5):217-21.
Background Ambulatory blood pressure monitoring (ABPM) has been used increasingly in assessing dialysis patients. However, devices have not been validated formally for this population. Formal device validation is important in order to guarantee adequate performance for populations with special characteristics, such as patients undergoing hemodialysis.
To achieve formal validation of the SpaceLabs 90207 ambulatory blood pressure device (SLD) using a modified British Hypertension Society protocol.
Eighty-five hemodialysis patients were studied, generating 255 readings. Readings were obtained with patients supine (in a dialysis chair) over 5-10 min during hemodialysis. Simultaneous, same-arm readings were obtained through the use of a T connector to a calibrated mercury manometer. The mean differences between readings obtained by observers and those obtained by the device were calculated. Limits of agreement between observers and SLD were determined and plotted according to the method of Bland and Altman. For grading of performance, we determined the number of readings for which the readings obtained by the device were within 5, 10, and 15mmHg of manometer readings. Final gradings were ascribed according to British Hypertension Society criteria.
The mean blood pressure (+/-SD) was 141/76+/-31/15mmHg (observers) and 141/77+/-27/15mmHg (SLD), and the mean (+/-SD) difference between observers and device (observer-device) was -0.5+/-7.5mmHg for systolic blood pressure (SBP) and -0.2+/-5.2mmHg for diastolic blood pressure (DBP). The device was less accurate in extreme ranges of SBP. In fact, there was a positive correlation between average [(observer+device)/2] and difference (observer-device) for SBP (r =0. 54, P <0.0001), showing that underestimation in higher ranges, and overestimation in lower ranges of blood pressure occurred for SBP. For SBP, 53% of readings were within 5mmHg of those obtained by the observers, 85% were within 10mmHg, and 97% within 15mmHg. For DBP, 78% were within 5mmHg, 96% within 10mmHg, and 98% within 15mmHg. These observations conferred on the device grade C for SBP and grade B for DBP. The type of vascular access and the presence of non-functioning arteriovenous grafts and fistulas in the ipsilateral arm did not alter these results significantly.
These data validate the use of this device for hemodialysis patients. However, caution should be exercised in the evaluation of upper and lower ranges of SBP.
动态血压监测（ABPM）在评估透析患者中的应用日益广泛。然而，相关设备尚未针对该人群进行正式验证。正式的设备验证对于确保其在具有特殊特征的人群（如接受血液透析的患者）中具有足够性能非常重要。
使用改良的英国高血压学会方案对太空实验室90207动态血压设备（SLD）进行正式验证。
对85例血液透析患者进行研究，共获得255次读数。在血液透析期间，让患者仰卧于透析椅上5 - 10分钟获取读数。通过T形连接器连接到校准的汞柱血压计，同时在同一手臂获取读数。计算观察者获得的读数与设备获得的读数之间的平均差异。根据布兰德和奥特曼方法确定观察者与SLD之间的一致性界限并绘图。为了评估性能等级，我们确定设备获得的读数与血压计读数相差在5、10和15mmHg范围内的读数数量。最终等级根据英国高血压学会标准确定。
平均血压（±标准差）观察者为141/76 ± 31/15mmHg，SLD为141/77 ± 27/15mmHg，观察者与设备之间收缩压（SBP）的平均（±标准差）差异为 - 0.5 ± 7.5mmHg，舒张压（DBP）为 - 0.2 ± 5.2mmHg。该设备在SBP的极端范围内准确性较低。实际上，SBP的平均[（观察者 + 设备）/2]与差异（观察者 - 设备）之间存在正相关（r = 0.54，P < 0.0001），表明SBP在较高血压范围存在低估，在较低血压范围存在高估。对于SBP，53%的读数与观察者获得的读数相差在5mmHg以内，85%在10mmHg以内，97%在15mmHg以内。对于DBP，78%在5mmHg以内，96%在10mmHg以内，98%在15mmHg以内。这些观察结果使该设备在SBP方面评定为C级，在DBP方面评定为B级。血管通路类型以及同侧手臂有无未发挥功能的动静脉移植物和瘘管并未显著改变这些结果。
这些数据验证了该设备在血液透析患者中的应用。然而，在评估SBP的上下限范围时应谨慎。
