Audit of Computed Tomographic Angiograms for Pulmonary Embolism in a Regional Hospital in Hong Kong
EMW Man, SY Luk, CS Cheng
Hong Kong J Radiol 2010;13:68-72
Objective: To audit requests for computed tomographic pulmonary angiograms, usage of pre-test pulmonary embolism probability scores, and D-dimer measurements in patients with suspected pulmonary embolism in aregional hospital in Hong Kong.
Methods: A retrospective study was performed for all computed tomographic pulmonary angiograms requested for clinically suspicious pulmonary embolism during the period of 1 January 2008 to 31 December 2008. Clinical notes were reviewed and patients were being included or excluded according to predefined inclusion and exclusion criteria.
Results: Of the 109 cases of computed tomographic pulmonary angiogram requests (after excluding 12), there were 25 who had pulmonary embolism. The percentage of computed tomographic pulmonary angiograms positive for pulmonary embolism was 23%. Not any documented standardised pre-test pulmonary embolism probability score was noted. D-dimer tests were performed in 27 cases, however, most of these requested tests were not performed according to 2003 British Thoracic Society guidelines.
Conclusion: There was a nearly 5-fold increase in requests for computed tomographic pulmonary angiograms for suspected pulmonary embolism over a 4-year period (2004 vs 2008). In our audit, the percentage reported positive was 23%, which was lower than most diagnostic study series in which the reported prevalence ranged from 28 to 33%. Reasons for this are multifactorial and may include a lower overall prevalence of pulmonary embolism in Chinese patients and speculations about ineffective patient selection by referring physicians. The latter possibility was supported by the observation that there was no documented use of any standardised pre-test pulmonary embolism probability score in our 109 cases. The audit also suggested misuse of D-dimer tests, which can be improved if the referring physicians were more aware of the sensitivity and the limitations of such tests.
中文摘要
香港一間地區醫院肺動脈栓塞患者的電腦斷層血管造影審核
萬民偉、陸嬈、鄭志成
目的：對香港一間地區醫院作以下三方面的審核：進行電腦斷層（CT）肺動脈血管造影的轉介病例，檢查前肺動脈栓塞預測值的使用，以及對懷疑肺動脈栓塞患者的D﹣二聚體的測量。
方法：用事先制定的排除及納入準則，回顧2008年1月1日至12月31日期間因懷疑患上肺動脈栓塞而進行CT肺動脈血管造影病人的病歷紀錄。
結果：研究期間，除了12宗病例無被納入研究範圍外，共有109宗要求進行CT肺動脈血管造影的轉介病例，其中肺動脈栓塞的確診病例有25個。CT肺動脈血管造影呈陽性結果的佔23%。病歷紀錄中並沒有記載任何肺動脈栓塞預測值的標準。有27個病例進行了D﹣二聚體測試，可是其中大部份未有根據英國胸科協會2003年的指引進行此檢測。
結論：因懷疑患上肺動脈栓塞而要進行CT肺動脈血管造影的病例數目，2008年比2004年四年間幾乎增加了5倍。本研究所得的陽性率為23%，比其他大部份診斷研究系列（陽性率為28%至33%）都要低。造成這結果有很多原因，其中包括患有肺動脈栓塞華籍病人的總發病率偏低；而且在缺乏肺動脈栓塞預測值標準的情況下，醫生可能未有一套有效的病人篩選準則所致。本研究亦發現D﹣二聚體測試有可能被不當使用，如果負責轉介的醫生能掌握此測試的敏感度及了解其限制，相信可以改善情況。