Published in the New England Journal of Medicine, this paper by van der Pol LM, et al. studied 510 expecting women to see if an algorithm could diagnose pulmonary embolism without the need for imaging.
The aim of the study is to see if it is an effective alternative to ventilation-perfusion scanning and CT pulmonary angiography. These two traditional tests expose both the pregnant woman and the fetus to radiation.
Researchers evaluated three criteria from the YEARS algorithm. They were the clinical signs of hemoptysis, pulmonary embolism, and deep-vein thrombosis. The D-dimer level was also measured. The team ruled out pulmonary embolism if the three criteria had not been met and there was a D-dimer level of less than 500 ng per milliliter.
The possibility was also eliminated if at least one criterium was met but had a D-dimer level of below 500 ng per milliliter.
By the end of the study, the researchers arrived at the conclusion that the adapted YEARS algorithm can rule out pulmonary embolism in expecting women across the three trimesters. However, the diagnosis efficiency was highest in the first trimester but lowest in the third.
Of the women, 32% to 65% managed to avoid CT pulmonary angiography.