Experimental gas embolism and tissue oxygenation using intravital microscopy
Abstract
Little is known about microhemodynamic responses to arterial gas embolism (AGE) and associated local O2 tensions (PO2) have never been evaluated in vivo. Therefore, we assessed the adequacy of intravital microscopy to study the microcirculation during AGE, and investigated how bubble‐induced vaso‐occlusion and blood flow redistribution were associated with changes in arteriolar and tissue PO2. Blood pressure and heart rate were not significantly different before and after local AGE in the rat cremaster muscle. The first attempt of embolization did not result in arteriolar occlusion and multiple attempts were needed. Control diameter and blood flow averaged 53 ± 25 and 13 ± 10 nl/s, respectively. After AGE, these parameters changed to 53 ± 24 µm and 1 ± 3 nl/s. Arteriolar PO2 averaged 59 ± 19 mmHg during control and dropped to 34 ± 27 mmHg (upstream) and 24 ± 22 mmHg (downstream) after AGE. Interstitial PO2 changed from 44 ± 22 to 23 ± 20 mmHg and did not follow the drop recorded in the embolized arteriole when the PO2 in nearby flowing vessels remained high. We also measured in vivo bubble reabsorption (volume ≤ 20pL). Our findings suggest that blood redistribution in the muscle prevented severe hypoxia in some tissue areas after AGE and that arteriolar entrapment of air bubbles is associated with prior endothelial cell damage caused by the first bubble passage.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 01, 2009
- Source ID
- 10.1096/fasebj.23.1_supplement.948.23
Entities
People
- Bruce D Spiess
- Ivo P. Torres Filho
- Luciana N. Torres
- Shreya Kanth
Organizations
- National Institutes of Health
- Office of Naval Research
- Virginia Commonwealth University