RT Journal Article
SR Electronic
T1 Age-adjusted D-dimers can safely exclude pulmonary embolism: Implications for a UK district general hospital
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P4102
VO 42
IS Suppl 57
A1 Craig Batista
A1 Jonathan Ratoff
YR 2013
UL http://erj.ersjournals.com/content/42/Suppl_57/P4102.abstract
AB IntroductionNegative D-dimers are used to reliably exclude pulmonary embolism (PE) in patients with an unlikely clinical probability. However, D-dimer values increase with age reducing the test’s specificity. Age-adjustment of the reference range’s upper limit (age x 0.01 mg/L) for patients older than 50 years has been suggested to overcome this problem. To understand how this might affect a typical district general hospital, we carried out a retrospective analysis between August and October 2012.MethodThe medical records of all patients admitted for the radiological investigation of PE with an unlikely clinical probability (two-tier Wells score) and a positive D-dimer (> 0.5 mg/L) were analysed. Patients older than 50 years had an alternative reference range calculated retrospectively (age x 0.01 mg/L).Results86 patients underwent computed tomography pulmonary angiography or ventilation perfusion imaging (78 and 8 respectively). The mean age was 70.9 years. Only 14 patients had PE (16%). A greater proportion of older patients had negative imaging: 92% (≥ 70 years) compared to 67% (< 70 years). We identified 28 patients with negative imaging, in whom PE could have been excluded with age-adjusted D-dimers alone; a potential 39% reduction in the need for radiology to exclude PE. All patients diagnosed with PE would still have undergone radiological investigation despite age-adjustment.DiscussionOur study demonstrates that the application of age-adjusted D-dimers is safe, improves the test’s sensitivity and significantly reduces the requirement for radiological investigation in an elderly population.