Pleural pressure measured with a rib capsule in anesthetized pneumonectomized rabbits

Pleural pressure was measured at end expiration in anesthetized rabbits using a rib capsule placed in the right fifth rib. Three groups of rabbits were studied in right and left lateral recumbency at least 8 weeks after surgery; rabbits that had undergone left pneumonectomy (Px, n = 8), rabbits that had undergone left pneumonectomy with wax plombage (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 nondependent), 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), pleural pressure was 0.64 +/- 0.22, 0.85 +/- 1.42, and 0.48 +/- 1.77 cmH2O respectively. In each position, pleural pressure did not differ among groups. This suggests that the compensatory increase in lung volume and reduced lung compliance following pneumonectomy in rabbits (Olson, J. Appl. Physiol. 74: 415-422, 1993) was not simply due to hyperinflation of the remaining lung.