Systemic and Pulmonary Haemodynamic Effects of Intravenous Infusion of Non-Ionic Isoosmolar Dimeric Contrast Media

Safety and Hemodynamic Effects of Pulmonary Angiography in Patients with Pulmonary Hypertension: 10-Year Single-Center Experience

OBJECTIVE

We sought to examine the incidence of complications and change in pulmonary artery pressure in patients with pulmonary hypertension who were undergoing pulmonary angiography.

MATERIALS AND METHODS

A retrospective review was performed for all patients who underwent pulmonary angiography over a 10-year period at a single institution. Patients with moderate pulmonary hypertension (pulmonary artery pressure, 30-59 mm Hg) and severe pulmonary hypertension (pulmonary artery pressure, >/= 60 mm Hg) served as the study population. Demographic data, clinical indication, pre- and postcontrast pulmonary artery pressure measurements, type of pulmonary hypertension, contrast agent volume, complications, and American Society of Anesthesiologists (ASA) classification were recorded for all patients and compared.

RESULTS

Two hundred two of 612 patients who underwent pulmonary angiography had pulmonary hypertension. Moderate pulmonary hypertension was present in 155 patients (77%) and severe pulmonary hypertension, in 47 patients (23%). Three (2.0%) of four complications were fatal. The complication rate was higher in patients with severe pulmonary hypertension compared with patients with moderate pulmonary hypertension but not statistically significant (6.3% vs 0.6%, p = 0.63). Patients with complications had a higher mean ASA score than those without complications (4.0 vs 3.0, p = 0.03). Patients with lung transplants had the greatest increase in pulmonary artery pressure after pulmonary angiography compared with all other clinical indications (16.75 +/- 12.97 mm Hg vs 5.46 +/- 6.86 mm Hg, p = 0.003).

CONCLUSION

The complication rate of pulmonary angiography in patients with pulmonary hypertension is low. However, in severely ill patients with acute pulmonary hypertension, pulmonary angiography should be undertaken with extreme caution.

The haemodynamic effects of iodinated water soluble radiographic contrast media: a review

All classes of iodinated water-soluble radiographic contrast media (RCM) are vasoactive with the iso-osmolar dimers inducing the least changes in the vascular tone. The mechanisms responsible for RCM-induced changes in the vascular tone are not fully understood and could be multifactorial. A direct effect on the vascular smooth muscle cells causing alterations in the ion exchanges across the cell membrane is thought to be an important factor in RCM-induced vasodilatation. The release of the endogenous vasoactive mediators adenosine and endothelin may also play a crucial role in the haemodynamic effects of RCM particularly in the kidney. In addition, the effects of RCM on blood rheology can cause a reduction in the blood flow in the microcirculation. The purpose of this review is to discuss the pathophysiology of the haemodynamic effects of RCM and to offer some insight into the biology of the endothelium and vascular smooth muscle cells as well as the pharmacology of the important vasoactive mediators endothelin and adenosine.