疑似肺栓塞的诊断策略:系统性综述和汇总分析

Systematic review and meta-analysis of strategies for the diagnosis of suspected pulmonary embolism

目的:评估肺栓塞诊断策略的似然比 (likelihood ratios),并通过验前概率(pretest probability)来决定其临床应用价值。数据来源:通过检索Medline,Embase, Pascal Biomed等网络资源,结合人工检索查找 1990年1月至2003年9月期间发表的文章。研究选择:选择评估确诊或排除肺栓塞的诊断性检查的研究。数据提取:确诊肺栓塞诊断策略的阳性似然比,排除肺栓塞诊断策略的阴性似然比。数据综合:1012篇文章中共有48篇入选。诊断性检查的阳性似然比为:肺通气灌注扫描呈高度可能为18．3(95％置信区间为10．3- 32．5),螺旋CT为24．1(12．4-46．7),下肢静脉超声为16．2(5．6-46．7)。如果患者具有中度或高度的肺栓塞验前概率,那么其验后概率将高于 85％。阴性似然比为:肺通气灌注扫描正常或接近正常为0．05(0．03-0．10);螺旋CT和超声波检查均阴性为0．04(0．03-0．06);定量酶联免疫吸附试验法所测定的D-dimer浓度小于500μg／L 的为0．08(0．04-0．18),如果肺栓塞验前概率为低度或中度,那么其验后概率则低于5％。然而,单纯螺旋CT、肺通气灌注扫描呈低度可能、磁共振血管造影、乳胶凝集法(latex)定量测定D- dimer以及全血凝集法测定D-dimer试验的阴性似然比也是较高的,从而只能排除那些肺栓塞验前概率低的诊断。结论:对于疑似肺栓塞的患者,各种诊断性检查的准确性差异很大。尽管如此,我们还是可以评估每一项确认或排除肺栓塞试验或策略的验前概率的范围。

Objective To assess the likelihood ratios of diagnostic strategies for pulmonary embolism and to determine their clinical application according to pretest probability. Data sources Medline, Embase, and Pascal Biomed and manual search for articles published from January 1990 to September 2003. Study selection Studies that evaluated diagnostic tests for confirmation or exclusion of pulmonary embolism. Data extracted Positive likelihood ratios for strategies that confirmed a diagnosis of pulmonary embolism and negative likelihood ratios for diagnostic strategies that excluded a diagnosis of pulmonary embolism. Data synthesis 48 of 1012 articles were included. Positive likelihood ratios for diagnostic tests were： high probability ventilation perfusion lung scan 18.3 （95% confidence interval 10.3 to 32. 5）, spiral computed tomography 24. 1 （ 12. 4 to 46. 7）, and ultrasonography of leg veins 16. 2 （5.6 to 46. 7）. In patients with a moderate or high pretest probability, these findings are associated with a greater than 85% post-test probability of pulmonary embolism. Negative likelihood ratios were ： normal or near normal appearance on lung scan 0.05 （0.03 to 0. 10）, a negative result on spiral computed tomography along with a negative result on ultrasonography 0. 04 （0. 03 to 0. 06 ）, and a D- dimer concentration 〈 500 μg/L measured by quantitative enzyme linked immunosorbent assay 0.08 （0.04 to 0.18）. In patients with a low or moderate pretest probability, these findings were associated with a post-test probability of pulmonary embolism below 5%. Spiral computed tomography alone, a low probability ventilation perfusion lung scan, magnetic resonance angiography, a quantitative latex D-dimer test , and haemagglutination D-dimers had higher negative likelihood ratios and can therefore only exclude pulmonary embolism in patients with a low pretest probability. Conclusions The accuracy of tests for suspected pulmonary embolism varies greatly, but it is possible to estimate the range of pretest probabilities over which each test or strategy can confirm or rule out pulmonary embolism.