European Journal of Cardio-Thoracic Surgery, Vol 10, 579-584, Copyright © 1996 by European Association for Cardio-thoracic Surgery
Endothelin plasma levels during heart surgery: influence on pulmonary artery pressure?
C Knothe, J Boldt, E Schindler, B Zickmann, S Konstantinov, F Dapper and G Hempelmann
Department of Anesthesiology and Intensive Care Medicine, Justus-Liebig- University, Giessen, Germany.
OBJECTIVE: Some studies found endothelin-1 to be a trigger for pulmonary
hypertension. Endothelin-1 is an endothelial derived substance with
generally vasoconstrictive properties, but probably vasodilatory effects on
pulmonary arteries. The aim of the present study was to look for influences
of endothelin-1 plasma values on pulmonary artery pressure. METHODS:
Endothelin-1 levels during and after cardiac surgery and correlations to
pulmonary artery pressure were tested in 10 control patients and 21
patients with pulmonary hypertension (mean pulmonary arterial pressure >
20 mmHg, systolic pulmonary arterial pressure > 30 mmHg). RESULTS:
According to endothelin-1 values before anaesthesia (normal value below 4
pg/ml) patients with pulmonary hypertension could be divided into a "high
endothelin-1" (10 patients, mean 8.25 +/- 2.06 pg/ml) and a "normal
endothelin-1" (11 patients, mean 2.13 +/- 0.86 pg/ml) subgroup (p <
0.01). Values of the "high endothelin-1" group decreased until end of
operation (from 7.58 +/- 2.35 to 2.95 +/- 1.44 pg/ml, n = 6) when pulmonary
artery pressure returned to normal. Otherwise they slightly increased (from
9.43 +/- 2.24 to 11.07 +/- 1.96 pg/ml, n = 4). Levels of the "normal
endothelin-1" group increased (to 2.55 pg/ml). Endothelin-1 values peaked
on the intensive care unit (ICU) in all patients. Baseline endothelin-1 and
systolic pulmonary artery pressure values correlated well with each other
(r = 0.73, p < 0.001). Endothelin-1 decreased after extracorporeal
circulation in all patients in whom pulmonary artery pressure tended to
normalise, whereas no rise in pulmonary artery pressure paralleled the
marked increase in endothelin-1 on the ICU. Vasodilatory effects of
endothelin on pulmonary arteries can attribute to this course. CONCLUSIONS:
Endothelin-1 seems not to trigger pulmonary hypertension but rather to
vasodilate pulmonary vasculature.
