Prostaglandin synthetase inhibitor treatment and the regulatory role of prostaglandins on organ perfusion.
Prostaglandin synthetase inhibitors (PGIs) are increasingly used in anesthetic practice and postoperative care. The influence of these agents on the hemodynamics and organ perfusion control remains largely unknown. This review attempts to assess the role of endogenous prostaglandins on the regulation of the microcirculation in different organs and to identify disease states in which PGIs may have deleterious effects. Prostanoids participate to the regulation of blood pressure as vascular tone is subject to the continuous relaxing influence from endogenous vasodilating prostaglandins or related substances. Prostacyclin (PGI2), probably the most important physiologic modulator, decreases blood pressure with concomitant increase in cardiac output and reduction of systemic vascular resistance related to the peripheral vasodilation. Also splanchnic, pulmonary and coronary vasodilation are observed with increased blood flows in the mesenteric, renal and coronary beds. These changes in regional blood flows have been linked to the inhibition by PGI2 of the vasoconstrictor response to sympathetic stimulation and pressor hormones (noradrenaline, angiotensin II). Other prostaglandins exert their effects by inhibiting the release of noradrenaline at the noradrenergic terminals of the sympathetic system. PGIs appear to provide hemodynamic stability during intra-abdominal surgery. Data suggest that the underlying mechanism is an increase in systemic vascular resistance. PGIs have beneficial effects in hemorrhagic shock models in animals and humans but can also exacerbate hemodynamic and metabolic derangements in acute hypovolemic hypotension. In animal models these agents reduce regional blood flow in the ischemic myocardium and may increase infarct size.(ABSTRACT TRUNCATED AT 250 WORDS)
Vanlersberghe
C
C
Department of Anesthesiology, Flemish Free University of Brussels Medical Center, Belgium.
Lauwers
M H
MH
Camu
F
F
D000818:Animals; D002318:Cardiovascular Diseases / Q000378:metabolism; D016861:Cyclooxygenase Inhibitors / Q000627:therapeutic use*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008833:Microcirculation / Q000187:drug effects; D011453:Prostaglandins / Q000494:pharmacology* / Q000502:physiology; D012039:Regional Blood Flow / Q000187:drug effects*; D013931:Thromboxanes / Q000494:pharmacology / Q000502:physiology
D016861:Cyclooxygenase Inhibitors; D011453:Prostaglandins; D013931:Thromboxanes