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: The influence of pulsatile perfusion on the vascular properties of the newborn lamb lung.
    Author: Johnson EH, Bennett SH, Goetzman BW.
    Journal: Pediatr Res; 1992 Apr; 31(4 Pt 1):349-53. PubMed ID: 1570201.
    Abstract:
    It is not known how the mode of flow alters the resistance properties of the newborn pulmonary circulation. Therefore, we compared the pressure responses of the perfused left pulmonary circulation of 16 newborn lambs with step changes in either pulsatile or steady flow. The slope of the pressure-flow curve differed significantly according to mode of perfusion. The slope of the pressure-flow curve was 0.125 +/- 0.115 mm Hg.mL-1.kg.min for pulsatile flow and 0.484 +/- 0.350 mm Hg.mL-1.kg.min for steady flow perfusion (p less than 0.05). The intercept pressure at zero flow was similar for both modes of flow, being 21.3 +/- 4.9 mm Hg for pulsatile flow compared with 23.8 +/- 11.3 mm Hg for steady flow perfusion. All perfusions with either mode of flow demonstrated flow-dependent decreases in pulmonary vascular resistance. However, the decreases in resistance were greater for pulsatile than for steady flow perfusion. In addition, the steady-perfused lungs demonstrated a significantly greater left lung wet/dry weight ratio than either the left lungs of pulsatile-perfused animals or the intact left lungs of 13 control animals not undergoing experimental perfusion (p less than 0.05). Thus, the mode of flow appears to play a major role in modulating the magnitude and distribution of pulmonary vascular resistance. This factor must be considered when interpreting the physiologic significance of hemodynamic experiments.
    [Abstract] [Full Text] [Related] [New Search]