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Magnetic Resonance Imaging Quantification of Pulmonary Perfusion using Calibrated Arterial Spin Labeling
Published on: May 30, 2011
The alveolar-arterial difference in oxygen tension increases with temperature-corrected determination during moderate
1Klinik für Anaesthesiologie und operative Intensivmedizin, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Germany. hansen@ukbf.fu-berlin.de
Anesthesia and Analgesia
|March 11, 1999
Summary
Moderate hypothermia increases the alveolar-arterial oxygen difference (AaDO2) during anesthesia. This change is only detectable when blood gases and water vapor pressure are corrected to actual body temperature.
Area of Science:
- Anesthesiology
- Physiology
- Respiratory Medicine
Background:
- Moderate hypothermia (32-33°C) is common in anesthesia.
- Intrapulmonary gas exchange during hypothermia requires further investigation.
Purpose of the Study:
- To investigate intrapulmonary gas exchange during moderate hypothermia.
- To assess the effect of temperature correction on blood gas analysis.
Main Methods:
- Eight patients undergoing anesthesia were studied during rewarming from 32°C hypothermia.
- Alveolar-arterial oxygen tension difference (AaDO2) and arterial to end-tidal carbon dioxide difference (Pa-ETCO2) were measured.
- Blood gases and water vapor pressure were analyzed corrected and uncorrected to actual body temperature.
Main Results:
- Temperature correction revealed a significantly higher AaDO2 at 33°C and 32°C compared to 36°C.
- Pulmonary oxygen exchange deterioration was not apparent without temperature correction.
- Respiratory quotient (RQ) and temperature-corrected Pa-ETCO2 remained unaffected by hypothermia.
Conclusions:
- Moderate hypothermia increases AaDO2, but only when blood gases and water vapor pressure are temperature-corrected.
- Carbon dioxide exchange and RQ are not significantly affected by moderate hypothermia.
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