Temporal course of gas exchange and mechanical compensation after
right pneumonectomy in immature dogs.
Takeda, S., E. Y. Wu, M. Ramanathan, A. S. Estrera, and C. C. W. Hsia.
Depts. of Medicine and Surgery, University of Texas Southwestern
Medical Center, Dallas, Texas 75235-9034
APStracts 3:0015A, 1996.
To determine the temporal progression and magnitude of functional
compensation in immature dogs raised to maturity after extensive lung
resection, we performed right pneumonectomy (R-PNX) or right
thoracotomy without pneumonectomy (SHAM) in matched foxhounds at 2
months of age. At 4, 8, 20, 40 and 60 weeks after surgery, static
transpulmonary pressure-lung volume relationships were determined.
Lung diffusing capacity (DLCO), membrane diffusing capacity (DMCO),
pulmonary capillary blood volume (Vc), pulmonary blood flow (c),
septal lung tissue volume (Vt) and lung volumes were measured
simultaneously by a rebreathing technique. During maturation, total
lung capacity, lung volume at a given distending pressure and
compliance were lower in the R-PNX than the SHAM group (p<0.05).
Pulmonary viscous resistance at maturity was elevated after R-PNX.
There were no significant differences in total DLCO, DMCO, Vc, c and
Vt between groups. Compensation of alveolar-capillary gas exchange
was complete by 4 to 8 weeks after R-PNX but compensation of
mechanical properties remained incomplete throughout maturation.
Relative magnitude of compensation after R-PNX was greater in
immature dogs than in adult dogs studied previously by similar
techniques.
Received 30 March 1995; accepted in final form 1 December 1995.
APS Manuscript Number A350-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 22 January 96