Occlusive mesenteric ischemia and its effects on jejunal intramucosal pH, mesenteric oxygen consumption and oxygen tensions from surfaces of the jejunum in anesthetized pigs.
OBJECTIVE
To investigate the effects of superior mesenteric artery (SMA) flow reduction on the jejunal intramucosal pH (pHi) and to compare these effects with corresponding changes of mesenteric oxygen transport variables and oxygen tensions on the surfaces of the jejunal serosa and mucosa.


METHODS
Prospective, randomized, controlled, experimental study.


METHODS
Animal research laboratory.


METHODS
20 domestic pigs.


METHODS
Mechanical flow reduction in the SMA. The animals were randomized to have an SMA flow of 0%, 25%, 38%, 50% or 100% (control).


RESULTS
Measurements (baseline, ischemia, reperfusion) consisted of hemodynamic and oxygen transport variables, SMA blood flow, mesenteric oxygen transport variables, pHi and oxygen tensions of the jejunal serosa and mucosa. Flow reduction in the SMA resulted in a significant decrease of pHi indicating ischemia earlier than mesenteric oxygen transport variables. The relationship between mesenteric oxygen delivery (DO2ms) and pHi during acute ischemia is best described by a sigmoid curve. There was a linear correlation between the changes of the jejunal surface oxygen tensions and pHi due to SMA flow reduction.


CONCLUSIONS
The sigmoid relationship between pHi and DO2ms indicated that pHi is a sensitive parameter for detecting ischemia at 50% of the baseline oxygen delivery and that below 25% there was no further decrease of pHi. In contrast, mesenteric and whole body oxygen transport parameters were not indicative of impaired mucosal oxygen supply.
Pargger
H
H
Department of Anesthesia, University of Basel, Kantonsspital, Switzerland. pargger@ubaclu.unibas.ch
Staender
S
S
Studer
W
W
Schellscheidt
O
O
Mihatsch
M J
MJ
Scheidegger
D
D
Skarvan
K
K
D000704:Analysis of Variance; D000818:Animals; D006439:Hemodynamics; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000098:blood supply*; D007511:Ischemia / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D007583:Jejunum / Q000378:metabolism* / Q000473:pathology; D016014:Linear Models; D008365:Manometry; D017538:Mesenteric Artery, Superior; D008641:Mesenteric Vascular Occlusion / Q000150:complications* / Q000378:metabolism / Q000503:physiopathology; D010101:Oxygen Consumption; D011446:Prospective Studies; D011897:Random Allocation; D018709:Statistics, Nonparametric; D013552:Swine