Update on the Wells Criteria for PE-patients with a score of 4 or less (which means low to moderate probability) can be considered for a "d-dimer negative" rule out approach. This is a bit of a change from the low risk only approach. Additionally, the British Thoracic Society guidelines support the low and moderate risk group patient rule out strategy. So, if you have a low or even moderate risk patient, you can use the approach of obtaining a highly sensitive d-dimer and if it is negative, the hunt for PE is over.
