The role of CT pulmonary angiography in patients with suspected pulmonary embolism admitted to general medicine.
BACKGROUND
CT pulmonary angiography (CTPA), D-dimer testing, and pre-test probability scoring have greatly improved the ability to manage patients with suspected pulmonary embolism. International guidelines suggest combining these investigations for the best yield. We have been investigating the use of CTPA in patients with suspected pulmonary embolism (PE) admitted to the Department of General Medicine at Christchurch Hospital, New Zealand.


METHODS
A retrospective audit of 100 patients with suspected pulmonary embolism who had a CTPA performed between October 2003 and April 2004.


RESULTS
CTPA was positive for PE in 31% of admissions. The pre-test probability was documented in only 4% of admissions. All patients with PE had a significantly elevated D-dimer (> 499 ng/mL). Wells score calculated by the investigators showed 59 (59%) to have a low, 33 (33%) a moderate, and 8 (8%) a high risk for PE. Of these, PE was diagnosed in 9 (15%), 15 (45%), and 7 (88%) respectively; 93% of patients had a blood gas performed, yet only 77% had the D-dimer measured. No patient with a measured and negative D-dimer had a diagnosis of a PE; 32 CTPAs were performed on 32 patients out of hours.


CONCLUSIONS
There was a very low uptake of the formal use of pre-test probability scores by medical registrars. This audit confirms that, in patients with low or moderate risk of PE and a negative D-dimer, an alternative diagnosis should be considered. The management of suspected venous thromboembolism (VTE) could be improved; it is likely that after hours CTPA could be reduced.
Chin
Paul
P
Department of General Medicine, Christchurch Hospital, Christchurch.
Hurrell
Mike
M
McGregor
David
D
Beckert
Lutz
L
D000792:Angiography / Q000191:economics / Q000592:standards / Q000706:statistics & numerical data*; D000933:Antifibrinolytic Agents / Q000032:analysis; D003362:Cost-Benefit Analysis; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D019983:Guideline Adherence / Q000706:statistics & numerical data; D006760:Hospitalization; D006801:Humans; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D009520:New Zealand; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011655:Pulmonary Embolism / Q000097:blood / Q000000981:diagnostic imaging*; D012189:Retrospective Studies
D000933:Antifibrinolytic Agents; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D