Venous thromboembolism: AAFP and ACP issue untried practice guidelines

New guidelines on diagnosis and management of insightful venous thrombosis and pulmonary embolism in primary consideration are derived from a well-done systematic review of the literature (1) performed by the Agency for Healthcare Research and Quality Evidence-Based Practice Centers. The recommendation were derived largely from fine randomized controlled trials (level of evidence: 1a).

What is the best diagnostic strategy?

Qaseem A, Snow V, Barry P, et al, for the Joint American Academy of Family Physicians/American College of Physicians Panel on Deep Venous Thrombosis/Pulmonary Embolism. Current diagnosis of venous thromboembolism in primary care: a clinical practice guideline from the American Academy of Family Physicians and the American College of Physicians. Ann Fam Med 2007; 5:57-62.

The guideline on diagnosis answers question about the role of clinical prediction rules, D-dimer test, ultrasounds, and computed axial tomography (CT) in the diagnosis of VTE.

Clinical prediction rules and D-dimer tests

The researchers found 19 studies using clinical prediction rules, 17 of which used the Wells prediction rule. These studies support the use of prediction rules for detecting VTE. With the combination of a unenthusiastic D-dimer result and a negative clinical prediction rule for low-risk patients, the probability of VTE is reasonably low.

Ultrasound

The Evidence-Based Practice Center review found ultrasound to be very sensitive (89%-96%) and specific (94%-99%) within diagnosing symptomatic proximal vein lower extremity thromboses. It is smaller number sensitive in diagnosing asymptomatic thromboses (47%-62%).

CT scans

The studies of CT be of variable feature and the results were thus less consistent. Because of this, further imaging is credible needed for patients who have a illustrious pretest probability of pulmonary embolism and a negative CT scan result.

REFERENCE

1. Segal JB, Eng J, Tamariz L J, Bass EB. Review of the evidence on diagnosis of cavernous venous thrombosis and pulmonary embolism. Ann Fam Med 2007; 5:63-73.

* Key points

1. Begin by using validated clinical prediction rules, similar to the Wells prediction rule, to estimate the clinical likelihood of VTE.

2. Order a high-sensitivity D-dimer assessment for patients with a low clinical prospect of VTE. A negative question paper result confirms that the patient is unlikely to hold a VTE.

3. Perform an ultrasound of the lower extremities of patients with an intermediate to elevated clinical likelihood of VTE.

4. Order diagnostic imaging studies for patients beside intermediate or high clinical prospect of pulmonary embolism.

FAST TRACK

Start with a clinical prediction rule (eg, Wells) to estimate chance of an embolism