Abstract
We compared the effects of left caudal lobe (LCL) alveolar hypoxia on regional pulmonary blood flow (PBF) with the effects due to alveolar edema induced by plasma instilled directly into the LCL airways of 16 dogs. Regional measurements were made with positron emission tomography. After hypoxic ventilation of the LCL (n = 11), the LCL-to-right caudal lobe (L/R) PBF ratio fell from 0.94 +/- 0.21 during 100% oxygen ventilation of the LCL to 0.46 +/- 0.21 (P less than 0.05). After instillation of either isooncotic (n = 5) or hypooncotic plasma (n = 3) into the LCL, the L/R PBF ratio was similar to that during LCL hypoxia (0.50 +/- 0.27 and 0.64 +/- 0.10, respectively, P less than 0.05 compared with 100% oxygen ventilation of the LCL before plasma instillation). The changes in regional PBF due to LCL hypoxia and plasma instillation could be completely prevented (n = 8) by the prior administration of a single dose of endotoxin (15 micrograms/kg iv). In contrast to previous work, these results indicate that perfusion redistribution occurs regardless of the oncotic state of alveolar edema. More importantly, any change that does occur in regional PBF can be completely prevented by blocking regional vasoconstriction, indicating that mechanical compression cannot be the major factor determining the regional response of PBF to alveolar flooding.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
