PLEURAL PRESSURE MEASURED WITH A RIB CAPSULE IN ANESTHETIZED PNEUMONECTOMIZED RABBITS

Pleural pressure was measured at end expiration in anesthetized rabbit s using a rib capsule placed in the right fifth rib. Three groups of r abbits were studied in right and left lateral recumbency at least 8 we eks after surgery; rabbits that had undergone left pneumonectomy (Px, n = 8), rabbits that had undergone left pneumonectomy with wax plombag e (Px + W, n = 7), and sham-operated control rabbits (S, n = 6). In S. Px. and Px+W rabbits in the left lateral position (lung and capsule n ondependent), pleural pressure was -2.11 +/- 0.88 (mean +/- SD), -2.65 +/- 0.23, and - 1.96 +/- 0.55 cmH2O respectively. In S. Px and Px + W rabbits in the right lateral position (lung and capsule dependent), p leural pressure was 0.64 +/- 0.22, 0.85 +/- 1.42, and 0.48 +/- 1.77 cm H2O respectively. In each position, pleural pressure did nol differ am ong groups. This suggests that the compensatory increase in lung volum e and reduced lung compliance following pneumonectomy in rabbits (Olso n, J. Appl. Physiol. 74: 415-422, 1993) was not simply due to hyperinf lation of the remaining lung.