Intramucosal-arterial Pco2 gradient does not reflect intestinal dysoxia in anemic hypoxia.
BACKGROUND
An increase in intramucosal-arterial Pco2 gradient (DeltaPco2) might be caused by tissue hypoxia or by diminished blood flow. Our hypothesis was that DeltaPco2 should not be altered in anemic hypoxia with preserved blood flow.


METHODS
In 18 anesthetized, mechanically ventilated sheep, oxygen transport was stepwise reduced by hemorrhage (hypovolemia, n = 9) or by hemorrhage and simultaneous dextran infusion (hemodilution, n = 9).


RESULTS
Hypovolemia and hemodilution produced comparable decreases in systemic and intestinal oxygen transport and uptake. However, mixed venoarterial and mesenteric venoarterial Pco2 gradients and DeltaPco2 were significantly higher in hypovolemia than in hemodilution (25 +/- 5 vs. 10 +/- 2 mm Hg; 21 +/- 6 vs. 10 +/- 5 mm Hg; and 41 +/- 18 vs. 14 +/- 9 mm Hg, respectively; p < 0.01).


CONCLUSIONS
DeltaPco2 did not reflect intestinal dysoxia during Vo2/Do2 dependency attributable to hemodilution. Blood flow seems to be the main determinant of DeltaPco2.
Dubin
Arnaldo
A
Cátedra de Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina. arnaldodubin@speedy.com.ar
Estenssoro
Elisa
E
Murias
Gastón
G
Pozo
Mario O
MO
Sottile
Juan P
JP
Barán
Marcelo
M
Piacentini
Enrique
E
Canales
Héctor S
HS
Etcheverry
Graciela
G
D000704:Analysis of Variance; D000740:Anemia / Q000150:complications*; D000818:Animals; D002245:Carbon Dioxide / Q000097:blood*; D004730:Endothelium, Vascular / Q000378:metabolism*; D006438:Hemodilution; D020896:Hypovolemia / Q000503:physiopathology; D000860:Hypoxia / Q000150:complications / Q000175:diagnosis*; D007511:Ischemia / Q000175:diagnosis; D008365:Manometry; D010101:Oxygen Consumption; D012756:Sheep; D013152:Splanchnic Circulation
D002245:Carbon Dioxide