Watters V A, Grant J P
Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA.
Ann Surg. 1997 Feb;225(2):165-71. doi: 10.1097/00000658-199702000-00004.
This study evaluated the accuracy of placing right atrial catheters using an electrocardiographic (ECG) technique.
Placement of right atrial catheters for vascular access is a common operative procedure. Accurate placement is essential for proper function. Previous placement techniques have used fluoroscopy, which is both time consuming and hazardous.
The accuracy of placement of 1236 right atrial catheters using an ECG technique was compared to placement of 586 catheters using fluoroscopy between March 1991 and November 1995. In the ECG technique, the catheter was flushed with sodium bicarbonate. A sterile left-leg ECG lead was attached to the catheter with the other ECG leads applied normally. On advancing the catheter through the superior vena cava, the P-wave amplitude (lead II) increased in negative deflection until greater than the QRS complex. Passing the sinoatrial node, the P-wave developed an initial positive then negative deflection. The catheter was positioned so the P-wave was biphasic, representing a position midway between the sinoatrial and atrioventricular nodes. For the fluoroscopic technique, catheters were positioned under direct observation just within the atrium estimated from cardiac contour. Use of contrast was optional if atrial anatomy was unclear.
Postoperative portable chest x-rays showed the ECG method to position the catheter tip within the right atrium just as accurately (average, 1.9 +/- 1.3 cm) as with the use of fluoroscopy (average, 1.1 +/- 1.6 cm). The ECG method eliminated an average of 20 seconds of radiation exposure, an average of 3.0 minutes operating room time (p < 0.04), avoided all risks of contrast dye, and saved $279.10 per case.
The ECG method is a satisfactory alternative to that of fluoroscopy for placement of long-term central venous catheters into the right atrium.
本研究评估了使用心电图（ECG）技术放置右心房导管的准确性。
为建立血管通路而放置右心房导管是一种常见的手术操作。准确放置对于正常功能至关重要。先前的放置技术使用荧光透视法，既耗时又有风险。
比较了1991年3月至1995年11月期间使用ECG技术放置1236根右心房导管与使用荧光透视法放置586根导管的准确性。在ECG技术中，用碳酸氢钠冲洗导管。将无菌左腿心电图导联连接到导管上，其他心电图导联按常规方式应用。当导管经上腔静脉推进时，P波振幅（导联II）在负向偏转时增加，直至大于QRS波群。通过窦房结时，P波先出现正向然后负向偏转。将导管定位，使P波呈双相，代表位于窦房结和房室结之间的中间位置。对于荧光透视技术，导管在直接观察下根据心脏轮廓估计置于心房内。如果心房解剖结构不清楚，可选择使用造影剂。
术后便携式胸部X线片显示，ECG方法将导管尖端置于右心房内的准确性与使用荧光透视法相同（平均，1.9±1.3 cm）（平均，1.1±1.6 cm）。ECG方法平均减少了20秒的辐射暴露，平均减少了3.0分钟的手术室时间（p<0.04），避免了所有造影剂风险，且每例节省279.10美元。
对于将长期中心静脉导管放置到右心房，ECG方法是荧光透视法的一种令人满意的替代方法。
