O. Chiara et al., Mesenteric and renal oxygen transport during hemorrhage and reperfusion: Evaluation of optimal goals for resuscitation, J TRAUMA, 51(2), 2001, pp. 356-362
Background. Changes in flow to the gut and the kidney during hemorrhage and
resuscitation contribute to organ dysfunction and outcome. We evaluated re
gional and splanchnic oxygen (O-2) now distribution and calculated oxygen s
upply distribution during hemorrhage and reperfusion and compared them with
global measures.
Methods: Seven anesthetized pigs were instrumented to evaluate global hemod
ynamics, visceral blood now, and oxygen transport. Tonometric pH probes wer
e positioned in the stomach and jejunum. Animals were bled to 45 mm Hg for
I hour. Crystalloids and blood were infused during the following 2 hours to
normalize blood pressure, heart rate, urine output, and hemoglobin.
Results: During hemorrhage, mesenteric flow and O-2 consumption were signif
icantly decreased, whereas systemic consumption remained normal. Renal flow
was reduced, but renal O-2 consumption remained normal. After resuscitatio
n, despite normal hemodynamics, neither systemic, mesenteric, nor renal O-2
delivery returned to baseline. Lactate remained significantly in-creased.
Arterial pH, base excess, and gastric and jejunal pH were all decreased.
Conclusion. During hemorrhage, the gut is more prone than other regions to
O-2 consumption supply dependency. After resuscitation, standard clinical p
arameters do not detect residual O-2 debt. Lactate, arterial pH, base exces
s, and intramucosal gut pH are all markers of residual tissue hypoperfusion
.