These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Ventilation-perfusion relationships with high cardiac output in lobar atelectasis.
    Author: Schumacker PT, Newell JC, Saba TM, Powers SR.
    Journal: J Appl Physiol Respir Environ Exerc Physiol; 1981 Feb; 50(2):341-7. PubMed ID: 7204208.
    Abstract:
    Pulmonary gas exchange was evaluated in 10 anesthetized mechanically ventilated dogs. Cardiac output (QT) was increased approximately 50% by opening peripheral arteriovenous fistulas. With both lungs ventilated, increasing QT increased mixed venous O2 both pressure (PO2) and pulmonary arterial pressure, but neither shunt fraction nor the distribution of ventilation-perfusion was consistently altered. During left lung atelectasis, increasing QT again increased mixed venous PO2 and pulmonary arterial pressure, but two different responses in shunt-like perfusion were measured. In four dogs, left lung atelectasis caused a shunt fraction of 46 +/- 6% that was not changed by high QT (P greater than 0.05). In six dogs, atelectasis caused a shunt fraction of 24 +/- 3% during normal QT that increased to 42 +/- 2% during high QT (P less than 0.001). Dogs whose shunt fraction during atelectasis was high and unchanged by QT had lower arterial pH (7.24 +/- 0.03) than dogs whose shunt fraction was initially lower and was increased with QT (7.36 +/- 0.02) (P less than 0.01). We conclude that increased QT can worsen shunt flow during lobar atelectasis when hypoxic vasoconstriction has been effective in limiting perfusion to the collapsed region at normal levels of QT.
    [Abstract] [Full Text] [Related] [New Search]