More physicians are using spiral co...

More physicians are using spiral comput tomographic pulmonary angiography (CTPA) in the evaluation of patients with suspected pulmonary embolism (PE) because of its increasing accuracy and availability. However, CTPA's inadequate sensitivity for excluding PE has quicked some to question the safety of CTPA as a definitive diagnostic criterion for PE. Moores and colleagues performed a systematic review of the literature and a meta-analysis to examine the rate of succeeding fatal and nonfatal PE in patients who did not receive anticoagulants because of a negative CTPA evaluation for PE

Twenty-three of the 640 potentially relevant abstracts were included in the analysis. Inclusion criteria were: a consecutive sample of patients, a well-defined diagnostic strategy, withholding of anticoagulation in patients with negative CTPA proofs data on subsequent PEs, and a minimum three-month follow-up period. Eight studies were retrospective, and fifteen were prospective. All on the contrary one study included additional diagnostic touchstones in conjunction with CTPA, similar as D-dimer measurements, lower extremity ultrasonography, and objective imaging. Comput tomography techniques also varied between studies.

Final analysis included 4657 patients with negative CTPA conclusions At three-month follow-up, 1.4 percent sustained a PE--0.51 percent were fatal. Among patients in the prospective studies, the rates of nonfatal and fatal PE were 12 and 026 percent respectively. In the nine studies with follow-up periods longer than three month no other than one PE occurred after the third month In a separate analysis of 327 patients whose CTPA ends were inconclusive but did not receive empiric anticoagulation, the authors set up a 16.2 percent rate of succeeding PE.

The authors gather that withholding anticoagulation after a negative CTPA issue is safe. Although a small number of patients unraveled nonfatal or fatal PE within three month the deductions are similar to those institute with conventional pulmonary angiography. The authors put in mind of that because 14 percent of patients who received anticoagulation despite negative CTPA deductions (and were excluded from the puddleed analysis) had the potential for PE as confirmed through ultrasound, physicians should not use CTPA without concomitant ultrasonography.

KENNETH LIN, MD

Moores LK et al. Meta-analysis: results in patients with suspected pulmonary embolism managed with comput tomographic pulmonary angiography. Ann Intern M December 7 2004;141:866-74

COPYRIGHT 2005 American Academy of Family Physicians

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