Barometric pressure and the incidence of pulmonary embolism

Reports in the literature suggest that weather changes may play a role in venous thrombotic disease. An increase in patients with pulmonary embolism (PE) during the spring season led us to investigate the relationship between atmospheric pressure (AP) and the incidence of PE, as diagnosed in most of the patients by helical CT angiography, and in the minority of patients by conventional pulmonary angiography and lung scanning.

We retrospectively investigated the charts of 91 consecutive patients with a diagnosis of PE who were evaluated by the Department of Pulmonary Medicine between August 2000 and September 2004. We documented AP changes as recorded by the Erzurum Provincial Department of Meteorology. Of the 91 patients, the diagnosis of PE was made by helical CT angiography in 84 patients, isotope lung scan in 5 patients, and conventional pulmonary angiography in 2 patients.

More patients presented in the spring months (March, n = 15; April, n = 10; and May, n = 12) than during other seasons (p < 0.001). The frequency of PE was inversely related to general average AP (r = - 0.70; p < 0.01). When the average seasonal AP was correlated with the incidence of PE, however, the relationship was found to not be statistically significant (r = - 0.66; p = 0.34). There was no correlation between the severity of PE or mortality and AP.

The incidence of PE was significantly higher in the spring months, when AP was low. A regional study to capture all PE patients will need to be done to confirm our findings. Other meteorologic factors should be investigated regarding their effect on thromboembolic disease.