Abstract
Hypoxemia during anesthesia can cause severe morbidity and mortality. To determine how the volatile anesthetics alter the normal hemodynamic compensation for hypoxemia, we investigated the effects of various anesthetics on regional blood flows during normoxemia and during normocapnic hypoxemia (FIO2 0.12 for 20 min) in rats. Using the radioactive microsphere method, organ blood flows were determined in animals anesthetized with 1 MAC of halothane, enflurane, or isoflurane and in awake animals. Brain blood flow increased significantly with hypoxemia in awake animals. However, brain blood flow decreased in all anesthetized animals that were hypoxemic. Coronary blood flow also increased significantly with hypoxemia in awake animals. In the presence of volatile anesthetics, coronary blood flow decreased, a decrease that was unchanged with hypoxemia. Thus, there was a large difference in brain and coronary blood flows between awake hypoxemic and anesthetized hypoxemic animals. Hypoxemia did not alter the magnitude of renal, gastrointestinal tract, or total hepatic blood flows in awake animals. However, all three blood flows decreased significantly in anesthetized hypoxemic animals. We conclude that volatile anesthetics modify the compensatory responses to hypoxemia that occur in awake animals, resulting in decreased blood flow to vital organs.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.