Komadina K H, Schenk D A, LaVeau P, Duncan C A, Chambers S L
Pulmonary/Critical Care Section, Wilford Hall USAF Medical Center, San Antonio, Tex.
Chest. 1991 Dec;100(6):1647-54. doi: 10.1378/chest.100.6.1647.
We evaluated the ability of three independent reviewers (R1, R2, R3) using waveform analysis to accurately identify confirmed valid PCWP tracings, and their ability to consistently report the PCWP numerical value.
Sixty PA and PCWP tracings were prospectively obtained and blindly reviewed by three independent critical care physicians.
The medical ICU of Wilford Hall USAF Medical Center.
Twenty mechanically ventilated patients with PA catheters inserted for hemodynamic assessment.
Sixty PA and PCWP tracings were reviewed blindly and independently for acceptability using waveform criteria by three critical care physicians. While recording all 60 tracings, blood was aspirated from the distal port of the PA catheter with the balloon "wedged" and blood gas analysis was done. Each reviewer analyzed the PCWP tracings for validity using waveform criteria, and reported a numerical PCWP reading for those tracings judged valid by waveform criteria. Reviewer sensitivity, specificity and accuracy in performing waveform analysis were assessed by comparing their predictions with those tracings that were confirmed their predictions with those tracings that were confirmed valid by the aspiration of pulmonary capillary blood. Inter-reviewer agreement upon which validity of PCWP tracings was based and reviewer agreement on the numerical PCWP reading were also assessed. All tracings were blindly reviewed by each physician, first without and then with an AP tracing to define end-expiration.
Thirty-eight of 60 PCWP tracings were confirmed valid by the aspiration of pulmonary capillary blood. In the remaining 22 tracings, mixed venous blood was aspirated with the balloon wedged, and tracing validity was unconfirmed. Reviewer accuracy in identifying was 50 percent for R1, 65 percent for R2 and 57 percent for R3. No reviewer's accuracy was significantly different from a random guess which would yield an accuracy of 50 percent. Agreement by all three reviewers in identifying valid PCWP tracings using waveform analysis varied from 37 percent in the absence of an AP tracing to 66 percent when an AP tracing was available to identify end-expiration (p less than 0.003). Agreement by all three reviewers on the PCWP numerical reading (within 4 mm Hg) was 79 percent without an AP tracing and 96 percent with an AP tracing (p = NS). The numerical reading reported by the ICU nurses and house staff correlated closely with the reviewers' readings. Agreement with the reported PCWP reading was improved only for R2 by the addition of an AP tracing.
We conclude that the validation of PCWP tracings by waveform analysis is subject to interobserver variability, and reviewer accuracy in identifying confirmed valid tracings was no better than a random guess. Agreement on the numerical PCWP reading was high among the reviewers as was agreement by each individual reviewer with the reported PCWP. Finally, the presence of an AP tracing, to define end-expiration, adds little to the interpretation of the PCWP numerical reading by experienced physicians.
我们评估了三位独立审阅者（R1、R2、R3）运用波形分析准确识别已确认有效的肺毛细血管楔压（PCWP）描记图的能力，以及他们一致报告PCWP数值的能力。
前瞻性获取60份肺动脉（PA）和PCWP描记图，并由三位独立的重症监护医师进行盲法审阅。
美国空军威尔福德·霍尔医疗中心的医学重症监护病房。
20例插入PA导管以进行血流动力学评估的机械通气患者。
三位重症监护医师使用波形标准对60份PA和PCWP描记图进行盲法且独立的可接受性审阅。在记录所有60份描记图时，在球囊“楔嵌”状态下从PA导管的远端端口抽取血液并进行血气分析。每位审阅者使用波形标准分析PCWP描记图的有效性，并对那些经波形标准判定为有效的描记图报告一个PCWP数值读数。通过将他们的预测与通过肺毛细血管采血确认有效的那些描记图进行比较，评估审阅者进行波形分析时的敏感性、特异性和准确性。还评估了审阅者之间关于PCWP描记图有效性的一致性以及审阅者关于PCWP数值读数的一致性。每位医师对所有描记图进行盲法审阅，首先不参考呼气末正压（AP）描记图，然后参考AP描记图以确定呼气末。
60份PCWP描记图中有38份经肺毛细血管采血确认有效。在其余22份描记图中，球囊楔嵌时抽取的是混合静脉血，描记图有效性未得到确认。R1识别的准确性为50%，R2为65%，R3为57%。没有一位审阅者的准确性与随机猜测（准确性为50%）有显著差异。三位审阅者使用波形分析识别有效PCWP描记图的一致性在没有AP描记图时为37%，在有AP描记图可用于确定呼气末时为66%（p<0.003）。三位审阅者关于PCWP数值读数（在4 mmHg范围内）的一致性在没有AP描记图时为79%，有AP描记图时为96%（p=无显著差异）。重症监护病房护士和住院医生报告的数值读数与审阅者的读数密切相关。仅对于R2，添加AP描记图后与报告的PCWP读数的一致性得到了改善。
我们得出结论，通过波形分析对PCWP描记图进行验证存在观察者间差异，并且审阅者识别已确认有效描记图的准确性并不比随机猜测更好。审阅者之间关于PCWP数值读数的一致性很高，每位审阅者与报告的PCWP读数的一致性也很高。最后，对于经验丰富的医生来说，用于确定呼气末的AP描记图对PCWP数值读数的解读帮助不大。
