Respiratory mechanics and gas exchange in postobstructive pulmonary vasculopathy

Abstract

R Re es sp pi ir ra at to or ry y m me ec ch ha an ni ic cs s a an nd d g ga as s e ex xc ch ha an ng ge e i in n p po os st to ob bs st tr ru uc ct ti iv ve e p pu ul lm mo on na ar ry y v va as sc cu ul lo op pa at th hy y ABSTRACT: Chronic unilateral pulmonary artery ligation induces formation of new bronchial collateral vessels in the affected lung. These vessels form precapillary anastomoses with the pulmonary circulation and the lung is perfused with arterial blood. Inspired gas is diverted to the contralateral lung to maintain the ventilation/ perfusion ratio (VA/Q) and gas exchange. This study was designed to determine the mechanism responsible for this shift of ventilation, which has not previously been investigated. We studied six dogs, before and 6 months after ligation of the left main pulmonary artery. We measured pulmonary resistance (RL) and elastance (EL), minute ventilation (VE), O 2 consumption (VO 2 ) and CO 2 production (VCO 2 ) of the right and left lungs. We also examined the effect of CO 2 , atropine and isoproterenol on RL and EL.In the lung with ligated pulmonary artery: 1) VE was significantly reduced; 2) RL and EL were increased and were unresponsive to CO 2 , atropine and isoproterenol; and 3) VO 2 decreased more than VCO 2 and, consequently, respiratory quotient (RQ) was greater than 1.We conclude that, with chronic pulmonary artery obstruction, ventilation shifts to the contralateral lung because of an increase in RL and EL not related to airway smooth muscle tone.

Production and transplantation of bioengineered lung into a large-animal model

“…4 Weill Cornell Medical College, New York, NY 10065, USA. 5 Department of Radiology, UTMB, Galveston, TX 77555, USA. 6 Pulmonary Division, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.…”

“…We performed a pilot study to establish feasibility of BEL transplantation, with an airway anastomosis but without a vascular (pulmonary) anastomosis. We relied on the development of collateral systemic circulation to support tissue survival (5,6). BELs were created using autologous cells isolated from a left lung pneumonectomy for n = 6 pigs.…”

Effects of preceding sialadenitis on the development of autoimmunity against salivary gland

“…In general, with paired organs, when the organ on one side is damaged in some way and its function deteriorates, the contralateral organ is thought to either maintain its function unchanged or undergo a compensatory elevation of function as in the lung and kidney (Kinn and Bohman, 1983; Kelly et al , 1995). This phenomenon has also been reported in the salivary glands (Scott et al , 1999).…”