Ginsberg J S, Wells P S, Hirsh J, Panju A A, Patel M A, Malone D E, McGinnis J, Stevens P, Brill-Edwards P
Department of Medicine, McMaster University, Hamilton, Ontario.
Arch Intern Med. 1994 Sep 12;154(17):1930-3.
To reevaluate the sensitivity of impedance plethysmography (IPG) for proximal deep vein thrombosis (DVT) and to establish a relationship between the location and size of thrombi and the results of IPG.
Prospective cohort study.
One hundred thirty-two consecutive patients with clinically suspected DVT underwent IPG testing and most (n = 118) underwent contrast-enhanced venography; in 14 patients, venous ultrasonography was performed and demonstrated definitive proximal DVT in which the size and extent of the thrombus could be delineated. All patients with dubious or normal ultrasound results underwent contrast-enhanced venography. All tests were performed and test results were interpreted without knowledge of the results of the other tests. Patients were considered to have proximal DVT if this was demonstrated on venography or ultrasound, calf DVT if this was demonstrated on venography, or no DVT if venography yielded normal findings. The sensitivity and specificity of IPG for DVT were calculated.
Of the 132 patients, 40 (30%) had proximal DVT, seven (5%) had calf DVT, and 85 (64%) had no DVT. The sensitivity of IPG for proximal DVT was 65% and the specificity was 93%. Of the proximal vein thrombi, IPG detected three (23%) of 13 that involved the popliteal vein but not the superficial femoral vein and 23 (85%) of 27 proximal vein thrombi that involved the superficial femoral vein.
Our study demonstrated that the sensitivity of IPG for proximal DVT at our center is only 65%, a figure that is much lower than those reported in earlier studies from our institution. We hypothesize that because of a change in referral practice, an increased proportion of patients with less severe symptoms are now referred to our center than in the past. These patients have thrombi that are smaller, less likely to be occlusive, and therefore less likely to yield abnormal IPG findings.
重新评估阻抗体积描记法（IPG）对近端深静脉血栓形成（DVT）的敏感性，并建立血栓的位置、大小与IPG结果之间的关系。
前瞻性队列研究。
132例临床怀疑为DVT的连续患者接受了IPG检测，大多数患者（n = 118）接受了静脉造影增强检查；14例患者进行了静脉超声检查，显示有明确的近端DVT，可描绘出血栓的大小和范围。所有超声结果可疑或正常的患者均接受静脉造影增强检查。所有检查均在不了解其他检查结果的情况下进行，检查结果也在不知情的情况下解读。如果静脉造影或超声显示有近端DVT，则患者被认为患有近端DVT；如果静脉造影显示有小腿DVT，则患者被认为患有小腿DVT；如果静脉造影结果正常，则患者被认为没有DVT。计算IPG对DVT的敏感性和特异性。
132例患者中，40例（30%）患有近端DVT，7例（5%）患有小腿DVT，85例（64%）没有DVT。IPG对近端DVT的敏感性为65%，特异性为93%。在近端静脉血栓中，IPG检测出13例累及腘静脉但未累及股浅静脉的血栓中的3例（23%），以及27例累及股浅静脉的近端静脉血栓中的23例（85%）。
我们的研究表明，IPG在我们中心对近端DVT的敏感性仅为65%，这一数字远低于我们机构早期研究报告的数字。我们推测，由于转诊方式的改变，与过去相比，现在转诊到我们中心的症状较轻的患者比例增加。这些患者的血栓较小，闭塞的可能性较小，因此产生异常IPG结果的可能性也较小。
