Cardiopulmonary adaptations to pneumonectomy in dogs. II. V̇A/Q̇ relationships and microvascular recruitment

C. C W Hsia, L. F. Herazo, M. Ramanathan, R. L. Johnson, P. D. Wagner

Research output: Contribution to journalArticlepeer-review

51 Scopus citations

Abstract

Ventilation-perfusion relationships, diffusing capacity for O2, and hemodynamic response were measured at rest and during exercise while five adult dogs breathed air and 15% O2 2 mo (Pnx-A, n = 2) or 12 mo (Pnx-B, n = 3) after right pneumonectomy (removal of 58% of lung tissue). Results were compared with those in five sham-operated controls. The multiple inert gas elimination technique was employed. Maximal O2 uptake was reduced by 50% in Pnx-A and by 15% in Pnx-B. Ventilation-perfusion matching was impaired in Pnx-A but not in Pnx-B. The increase in O2 diffusing capacity during exercise was significantly restricted in Pnx-A but was partially restored in Pnx-B. Mean pulmonary arterial pressure at a given blood flow through the remaining lung was normal in Pnx-A but lower than normal in Pnx-B compared with control values for a single lung. Stroke volume and cardiac output were lower in both Pnx-A and Pnx-B than in controls at a given exercise level. All functional abnormalities were more severe at 2 mo than at 12 mo postpneumonectomy. Gas phase diffusion resistance was present in both Pnx-A and Pnx-B but not in controls. We conclude that physiological compensation postpneumonectomy is progressive. Inability to recruit pulmonary vascular bed with incremental perfusion pressure or flow appears to be the major pathophysiological process that limits early functional capacity after right pneumonectomy.

Original languageEnglish (US)
Pages (from-to)1299-1309
Number of pages11
JournalJournal of applied physiology
Volume74
Issue number3
DOIs
StatePublished - 1993

Keywords

  • cardiac output
  • compensation
  • exercise
  • lung resection
  • multiple inert gas elimination technique
  • oxygen diffusing capacity
  • pulmonary arterial pressure
  • pulmonary vascular resistance
  • stroke volume
  • ventilation-perfusion distribution

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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