Wells P S, Anderson D R, Bormanis J, Guy F, Mitchell M, Gray L, Clement C, Robinson K S, Lewandowski B
Department of Medicine, University of Ottawa, Ontario, Canada.
Lancet. 1997;350(9094):1795-8. doi: 10.1016/S0140-6736(97)08140-3.
When ultrasonography is used to investigate deep-vein thrombosis, serial testing is recommended for those who test negative initially. Serial testing is inconvenient for patients and costly. We aimed to assess whether the calculation of pretest probability of deep-vein thrombosis, with a simple clinical model, could be used to improve the management of patients who present with suspected deep-vein thrombosis.
Consecutive outpatients with suspected deep-vein thrombosis had their pretest probability calculated with a clinical model. They then underwent compression ultrasound imaging of proximal veins of the legs. Patients at low pretest probability underwent a single ultrasound test. A negative ultrasound excluded the diagnosis of deep-vein thrombosis whereas a positive ultrasound was confirmed by venography. Patients at moderate pretest probability with a positive ultrasound were treated for deep-vein thrombosis whereas patients with an initial negative ultrasound underwent a single follow-up ultrasound 1 week later. Patients at high pretest probability with a positive ultrasound were treated whereas those with negative ultrasound underwent venography. All patients were followed up for 3 months for thromboembolic complications.
95 (16.0%) of all 593 patients had deep-vein thrombosis; 3%, 17%, and 75% of the patients with low, moderate, and high pretest probability, respectively, had deep-vein thrombosis. Ten of 329 patients with low pretest probability had the diagnosis confirmed, nine at initial testing and one at follow-up. 32 of 193 patients with moderate pretest probability had deep-vein thrombosis, three diagnosed by the serial (1 week) test, and two during follow-up. 53 of 71 patients with high pretest probability had deep-vein thrombosis (49 by the initial ultrasound and four by venography). Only three (0.6%) of all 501 (95% CI 0.1-1.8) patients diagnosed as not having deep-vein thrombosis had events during the 3-month follow-up. Overall only 33 (5.6%) of 593 patients required venography and serial testing was limited to 166 (28%) of 593 patients.
Management of patients with suspected deep-vein thrombosis based on clinical probability and ultrasound of the proximal deep veins is safe and feasible. Our strategy reduced the need for serial ultrasound testing and reduced the rate of false-negative or false-positive ultrasound studies.
当使用超声检查来研究深静脉血栓形成时，建议对最初检查结果为阴性的患者进行系列检测。系列检测对患者来说不方便且成本高。我们旨在评估使用一个简单的临床模型计算深静脉血栓形成的预检概率是否可用于改善疑似深静脉血栓形成患者的管理。
连续的疑似深静脉血栓形成的门诊患者使用临床模型计算其预检概率。然后他们接受腿部近端静脉的压迫超声成像检查。预检概率低的患者接受单次超声检查。超声检查结果为阴性可排除深静脉血栓形成的诊断，而超声检查结果为阳性则通过静脉造影确认。预检概率中等且超声检查结果为阳性的患者接受深静脉血栓形成的治疗，而最初超声检查结果为阴性的患者在1周后接受单次随访超声检查。预检概率高且超声检查结果为阳性的患者接受治疗，而超声检查结果为阴性的患者接受静脉造影检查。所有患者随访3个月以观察血栓栓塞并发症。
593例患者中95例（16.0%）患有深静脉血栓形成；预检概率低、中等和高的患者中分别有3%、17%和75%患有深静脉血栓形成。329例预检概率低的患者中有10例确诊，9例在初次检查时确诊，1例在随访时确诊。193例预检概率中等的患者中有32例患有深静脉血栓形成，3例通过系列（1周）检查确诊，2例在随访期间确诊。71例预检概率高的患者中有53例患有深静脉血栓形成（49例通过初次超声检查确诊，4例通过静脉造影确诊）。在所有501例（95%CI 0.1 - 1.8）被诊断为没有深静脉血栓形成的患者中，只有3例（0.6%）在3个月的随访期间发生了相关事件。总体而言，593例患者中只有33例（5.6%）需要进行静脉造影检查，系列检测仅限于593例患者中的166例（28%）。
基于临床概率和近端深静脉超声检查对疑似深静脉血栓形成患者进行管理是安全可行的。我们的策略减少了系列超声检查的需求，并降低了超声检查假阴性或假阳性的发生率。
