The effects of cigarette smoking on pulmonary hemodynamics

Neutrophils are delayed in transit in the pulmonary circulation during smoking which could reflect smoke-induced changes in local hemodynamics. The purpose of this study was to measure the changes in pulmonary hemodynamics during cigarette smoking in both healthy smokers and patients with COPD with and without pulmonary hypertension. In eight healthy smokers, cigarette smoking decreased the transit time of technetium-99m-labeled red blood cells, associated with an increase in cardiac output and a fall in the pulmonary blood volume index. In patients with COPD, the cardiac index also increased during smoking associated with a small increase in pulmonary arterial pressure only in those patients with pulmonary hypertension. However, pulmonary vascular resistance fell. These changes in pulmonary hemodynamics during cigarette smoking could not account for the increased neutrophil sequestration that has been observed previously in the lungs during smoking.