Effect of Indomethacin on Peripheral Tissue Perfusion After Coronary Artery Bypass Surgery

Abstract

The effect of indomethacin on peripheral tissue perfusion in the early phase after coronary artery bypass grafting (CABG) was investigated in ten patients randomly allocated to receive indomethacin 25 mg i.v. or placebo ‘double-blind’. The patients were coupled to a respirator with FiO₂ 30 v/v%. Central haemodynamics, intrapulmonary shunt and blood gases showed no significant change in either group during the 2-hour study period. The thromboxane A₂ metabolite P-TXB₂ decreased significantly (p<0.05) in the indomethacin group, but the prostacyclin metabolite P-6-K PGF_1α showed no significant change in either group. The PtcO₂ index (transcutaneous oxygen tension/arterial PO₂), measured in the upper extremity, rose (p<0.05) after indomethacin infusion, but was almost unchanged in the controls. The mean subcutaneous tissue oxygen tension and the laser-Doppler skin red-cell flux underwent no significant change. The data thus suggested that indomethacin administered intravenously post-CABG may exert beneficial effects on peripheral tissue perfusion and oxygenation, possibly mediated by improvements in prostacyclin-thromboxane balance and microcirculation.

Key Words:

• indomethacin
• prostacyclin
• chromboxane
• cardiac surgery
• haemodynamics
• tissue oxygen tension
• transcutaneous oxygen tension
• laser-Doppler flowmetry