Effects of intra-aortic balloon occlusion on intestinal perfusion, oxygen metabolism and gastric mucosal PCO2 during experimental hemorrhagic shock.
BACKGROUND
Aortic occlusion has been suggested for the initial treatment of severe uncontrolled hemorrhagic shock. Our objective is to determine the impact of aortic occlusion, during hemorrhagic shock, on splanchnic mucosal perfusion and to correlate these findings with other systemic and regional markers of splanchnic ischemia.


METHODS
Fourteen dogs (17 +/- 1.7 kg) anesthetized with pentobarbital were bled to a mean arterial pressure (MAP) of 40 mm Hg. After 30 min, the animals were randomly assigned to controls (no aortic occlusion, n = 7) and transfemoral aortic occlusion (TAO) at T9 level (n = 7). Superior mesenteric artery blood flow (SMABF, ultrasonic flow probe), gastric mucosal PCO2 (gastric tonometry) and splanchnic oxygen extraction ratio (O2ERsplanc) were evaluated for 120 min.


RESULTS
Hemorrhage caused a marked reduction in SMABF and increases in PCO2-gap and O2ERsplanc in both groups. TAO significantly improved MAP and further increased the PCO2-gap and O2ERsplanc, with a decreased SMABF. After reperfusion, SMABF, MAP and O2ERsplanc returned to pre-occlusion values, although the PCO2-gap remained higher in the TAO group.


CONCLUSIONS
Aortic occlusion promotes blood pressure restoration with an additional insult to mucosal perfusion, which could be adequately predicted by global and/or splanchnic oxygen-derived variables during ischemia, but not during the early reperfusion period.
Cruz
R J
RJ
Division of Applied Physiology, Heart Institute - InCor, University of São Paulo Medical School, São Paulo, Brazil. expcruzjr@incor.usp.br
Poli de Figueiredo
L F
LF
Bras
J L M
JL
Rocha e Silva
M
M
D000818:Animals; D001013:Aorta, Thoracic; D021721:Balloon Occlusion; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000378:metabolism; D004285:Dogs; D005753:Gastric Mucosa / Q000098:blood supply / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy; D008297:Male; D010100:Oxygen / Q000378:metabolism; D012771:Shock, Hemorrhagic / Q000378:metabolism / Q000503:physiopathology* / Q000628:therapy*; D013152:Splanchnic Circulation
D002245:Carbon Dioxide; D010100:Oxygen