Altered reactivity to acetylcholine in the pulmonary circulation after cardiopulmonary bypass is part of reperfusion injury.
OBJECTIVE
To investigate whether a time sequence of acetylcholine (ACH) reactivity indicative of endothelial reperfusion injury could be demonstrated in the pulmonary circulation in patients after cardiopulmonary bypass (CPB).


METHODS
Prospective study.


METHODS
Operating theater and intensive care unit of a university hospital.


METHODS
10 ASA physical status III and IV patients with ischemic or valvular heart disease.


METHODS
Pulmonary vascular resistance index (PVRI) was measured before and during an infusion of ACH. This procedure was done after induction of anesthesia but before surgery, immediately after weaning from bypass, and at 1 to 1.5 and 4 hours after CPB.


RESULTS
ACH caused a decrease in PVRI before (p < 0.01) and directly after CPB (p < 0.05) but not at 1 to 1.5 or 4 hours after bypass.


CONCLUSIONS
The maintained reactivity to ACH directly after CPB, followed by no reaction at 1 to 1.5 and 4 hours, was in agreement with experimental findings and indicates endothelial reperfusion injury caused by the period with no blood flow through the pulmonary artery during CPB and subsequent reperfusion.
Angdin
M
M
Department of Surgical Sciences, Karolinska Institute, Stockholm, Karolinska Hospital, Stockholm, Sweden.
Settergren
G
G
Astudillo
R
R
Liska
J
J
D000109:Acetylcholine; D000368:Aged; D002315:Cardiopulmonary Bypass; D005112:Extracorporeal Circulation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis*; D011292:Premedication; D011479:Protamines / Q000494:pharmacology; D011652:Pulmonary Circulation / Q000187:drug effects*; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology
D011479:Protamines; D000109:Acetylcholine