Pulmonary blood flow regulation: Influence of positive pressure ventilation

J. L. Theissen, S. R. Fischer, L. D. Traber, D. L. Traber

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Positive pressure ventilation with PEEP has been reported to reduce hypoxic pulmonary vasoconstriction (HPV) and thus increase venous admixture. This effect was investigated in six chronically instrumented unanesthetized healthy sheep. The change in left pulmonary arterial blood flow (Q̇lpa, ultrasonic transit time) in response to unilateral lung hypoxia (10 min of N2 alternately to the left (LLH) and right lung (RLH)) was evaluated during mechanical ventilation with and without PEEP of 10 cm H2O in comparison to spontaneous breathing. In the spontaneously breathing animal and during mechanical ventilation without PEEP, Q̇lpa decreased during LLH from 30% to 16% of cardiac index, during RLH it increased to 51%. With 10 cm H2O of PEEP, Q̇lpa showed an identical reaction to hypoxia both in the left and right lung. It is concluded that mechanical ventilation and PEEP up to 10 cm H2O does not interfere with pulmonary blood flow regulation to hypoxia.

Original languageEnglish (US)
Pages (from-to)251-260
Number of pages10
JournalRespiration Physiology
Issue number2-3
StatePublished - Dec 1995
Externally publishedYes


  • Blood flow, pulmonary artery
  • Hypoxia, pulmonary vasoconstriction
  • Hypoxic pulmonary vasoconstriction
  • Mammals, sheep
  • PEEP
  • Positive pressure ventilation

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine


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