Acetylcholine reactivity in the pulmonary artery during cardiac surgery in patients with ischemic or valvular heart disease.
OBJECTIVE
During cardiopulmonary bypass, there is almost no blood flow through the pulmonary artery. Ischemia and reperfusion are known to attenuate the reaction to acetylcholine. An attenuated reactivity to acetylcholine in the pulmonary circulation after cardiopulmonary bypass was previously shown in children. The current study in adult patients was designed to analyze the change over time of acetylcholine reactivity after cardiac surgery.


METHODS
A prospective study.


METHODS
The operating room and intensive care unit of a university hospital.


METHODS
Eighteen patients with ischemic or valvular heart disease.


METHODS
Pulmonary vascular resistance was measured with a pulmonary artery catheter before and during an infusion of acetylcholine. This procedure was done after induction of anesthesia before surgery and 1, 4, 8, and 20 to 24 hours after cardiopulmonary bypass.


RESULTS
Pulmonary vascular resistance index decreased during infusion of acetylcholine before surgery by 27% from 286 +/- 27 dyne/sec/cm-5/m2 (mean and standard error of mean) to 209 +/- 28 and at 8 and 20 to 24 hours by 23% and 34%, respectively, 288 +/- 27 to 221 +/- 29 and 229 +/- 22 to 150 +/- 17 (p < 0.001, paired t-test). One and 4 hours after cardiopulmonary bypass, no significant decrease was observed.


CONCLUSIONS
These results confirm the finding of altered reactivity to acetylcholine in the pulmonary circulation after cardiopulmonary bypass. In view of the often prolonged tendency toward pulmonary hypertension observed in children, the recovery at 8 hours after surgery was unexpectedly rapid. The attenuated response to acetylcholine is most likely explained by relative ischemia in the pulmonary circulation during cardiopulmonary bypass.
Angdin
M
M
Department of Cardiothoracic Anaesthetics and Intensive Care, Karolinska Hospital, Stockholm, Sweden.
Settergren
G
G
D000109:Acetylcholine / Q000008:administration & dosage / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000601:surgery; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002315:Cardiopulmonary Bypass; D002407:Catheterization, Swan-Ganz; D001026:Coronary Artery Bypass; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000601:surgery*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology; D007261:Infusions, Intra-Arterial; D007511:Ischemia / Q000503:physiopathology; D008168:Lung / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D017202:Myocardial Ischemia / Q000601:surgery*; D015425:Myocardial Reperfusion; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000187:drug effects*; D011652:Pulmonary Circulation / Q000187:drug effects; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D000109:Acetylcholine