Effect of acute hemodilution on intestinal perfusion and intramucosal pH after shock.
BACKGROUND
Restoration of oxygen delivery, especially to the splanchnic bed, is of critical importance during trauma resuscitation. Acute normovolemic hemodilution (ANH) has been used to reduce blood transfusion requirement during elective surgery. The effect of hemodilution on the splanchnic circulation during hemorrhagic shock (HS) is not well defined.


METHODS
Swine were instrumented to measure systemic and splanchnic circulation effects of ANH after HS. The adequacy of the splanchnic circulation was assessed by changes in measured mucosal blood flow, mucosal tonometry, as well as by portal venous blood O2 saturation, portal venous CO2 saturation, and lactate.


RESULTS
ANH after HS resulted in a final hematocrit of 18+/-2%. Superior mesenteric artery blood flow was returned to baseline levels; however, mucosal blood flow was still only 64% of baseline levels. However, at the same time mucosal PCO2 and intramucosal pH as well as portal venous O2 and CO2 saturation had normalized.


CONCLUSIONS
As long as an adequate intravascular volume is maintained, hemodilution is well tolerated by the gut after HS. Concern about the adequacy of gut perfusion should not be a transfusion trigger after HS.
Diebel
L N
LN
University Health Center, Wayne State University, Detroit, Michigan 48201, USA.
Tyburski
J G
JG
Dulchavsky
S A
SA
D000818:Animals; D001783:Blood Flow Velocity; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood; D004195:Disease Models, Animal; D006438:Hemodilution / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000098:blood supply*; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D012771:Shock, Hemorrhagic / Q000378:metabolism* / Q000503:physiopathology*; D013152:Splanchnic Circulation / Q000502:physiology*; D013552:Swine
D002245:Carbon Dioxide; D010100:Oxygen