Evaluation of intestinal intramucosal pH, arterial and portal venous blood gas values, and intestinal blood flow during small intestinal ischemia and reperfusion in dogs.
OBJECTIVE
To determine whether small intestinal ischemia and reperfusion affects intestinal intramucosal pH (pHi), arterial and portal venous blood gas values, and intestinal blood flow (IBF) and to investigate relationships between regional intestinal tissue oxygenation and systemic variables in dogs.


METHODS
15 healthy adult Beagles.


METHODS
Occlusion of superior mesenteric artery (SMA) for 0, 30, or 60 minutes, followed by reperfusion for 180 minutes, was performed; IBF, pHi, arterial and portal venous blood gas values, arterial pressure, and heart rate were measured at various time points; and intestinal mucosal injury was histologically graded.


RESULTS
Occlusion of the SMA induced significant decreases in pHi and IBF. After the release of the occlusion, IBF returned rapidly to baseline values, but improvement in pHi was slow. Arterial and portal venous blood gas analyses were less sensitive than tonometric measurements of pHi, and there was no correlation between results of blood gas analyses and tonometric measurements. Histologic score for intestinal mucosal injury increased significantly, depending on duration of ischemia, and there was a correlation between tonometric results and the histologic score.


CONCLUSIONS
Results suggest that it is difficult to accurately evaluate local oxygenation disorders by monitoring at the systemic level, whereas clinically pHi is the only reliable indicator of inadequate regional intestinal tissue oxygenation in dogs.
Nezu
Yoshinori
Y
Department of Veterinary Science, Nippon Veterinary and Animal Science University, Tokyo, Japan.
Sakaue
Yoko
Y
Hara
Yasushi
Y
Tsuchida
Shuichi
S
Yokota
Fumiyo
F
Takahashi
Kimimasa
K
Tagawa
Masahiro
M
D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D001794:Blood Pressure / Q000502:physiology; D004283:Dog Diseases / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006651:Histocytochemistry / Q000662:veterinary; D006863:Hydrogen-Ion Concentration; D007410:Intestinal Diseases / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000662:veterinary*; D007413:Intestinal Mucosa / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D008297:Male; D017538:Mesenteric Artery, Superior / Q000503:physiopathology; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*