Comparison of adenosine, isoflurane, and desflurane on myocardial tissue oxygen pressure during coronary artery constriction in dogs.
OBJECTIVE
To compare adenosine-, isoflurane-, or desflurane-induced hypotension with and without left anterior descending (LAD) coronary artery constriction for the effects on myocardial tissue oxygen pressure (PmO(2)) in dogs.


METHODS
Prospective, randomized, nonblinded.


METHODS
University teaching hospital.


METHODS
Male nonpurpose-bred dogs (n = 18).


METHODS
Dogs were anesthetized with 1.5% isoflurane (n = 12) or 8% desflurane (n = 6). A flow probe and balloon occluder were placed on the LAD artery. A probe that measured myocardial oxygen pressure was inserted into the middle myocardium in the LAD region. Myocardial oxygen consumption (MVO(2)) was calculated as LAD flow x arterial minus coronary sinus oxygen content.


RESULTS
Measures were made during hypotension produced by adenosine infusion, 2.8% isoflurane, or 14% desflurane with and without LAD constriction to decrease blood flow 30%. Without LAD artery constriction, adenosine infusion increased LAD flow 90% and MVO(2) 70%, 2.8% isoflurane produced no change in MVO(2), and 14% desflurane decreased MVO(2) 25%, but no treatment changed PmO(2). LAD artery constriction decreased PmO(2) 50% by itself. Adenosine infusion during LAD constriction decreased tissue oxygen pressure an additional 60%, 2.8% isoflurane produced no change, and 14% desflurane increased PmO(2) 100%.


CONCLUSIONS
There was an inverse relationship between the effect of adenosine, 2.8% isoflurane, and 14% desflurane on MVO(2) and PmO(2) during ischemia. This is consistent with reports that increasing oxygen demand worsens myocardial ischemia.
Hoffman
William E
WE
Department of Anesthesiology and Physiology, University of Illinois at Chicago, Chicago, IL 60612, USA. whoffman@uic.edu
Albrecht
Ronald F
RF
Jonjev
Zivojin S
ZS
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002245:Carbon Dioxide / Q000378:metabolism; D003251:Constriction, Pathologic / Q000378:metabolism*; D003326:Coronary Circulation / Q000187:drug effects; D023921:Coronary Stenosis / Q000378:metabolism*; D000077335:Desflurane; D004195:Disease Models, Animal; D004285:Dogs; D006339:Heart Rate / Q000187:drug effects; D007022:Hypotension / Q000139:chemically induced / Q000378:metabolism; D007530:Isoflurane / Q000031:analogs & derivatives* / Q000494:pharmacology*; D008297:Male; D008955:Models, Cardiovascular; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D011446:Prospective Studies; D011897:Random Allocation; D014665:Vasodilator Agents / Q000494:pharmacology*
D014665:Vasodilator Agents; D002245:Carbon Dioxide; D000077335:Desflurane; D007530:Isoflurane; D000241:Adenosine; D010100:Oxygen