thromboxane-b2 and Flushing

Mesenteric traction during aortic surgery produces facial flushing, reduced mean arterial pressure (MAP), and systemic vascular resistance (SVR) with increased heart rate (HR) and cardiac index (CI). Elevated 6-keto-prostaglandin-F1 alpha (6-keto-PGF1 alpha) suggests prostacyclin is the mediator. To test this hypothesis, the cyclooxygenase inhibitor, ibuprofen (n = 14), or placebo (n = 13) was administered to patients electively scheduled for aortic reconstruction. The hemodynamic measurements and plasma concentrations of prostanoids between groups were compared immediately before (0), and 5, 10, 15, 30, and 45 min following mesenteric traction. Following mesenteric traction significant differences (P less than 0.05) were observed between the ibuprofen pretreatment and placebo group over time in SVR, MAP, HR, CI, 6-keto-PGF1 alpha, and thromboxane B2 (TXB2). Significant differences between groups at individual times were found in SVR, HR, CI, 6-keto-PGF1 alpha, and TXB2. In the placebo group flushing was accompanied by reduced SVR and MAP and increased HR and CI. The greatest effect was seen at 10 min and resolved over 30 min. Plasma concentration of 6-keto-PGF1 alpha increased from 159 +/- 103 (mean +/- SEM) pg/ml to a peak value of 3,765 +/- 803 at 10 min. A late increase in TXB2 occurred with a peak value of 1,970 +/- 891 (mean +/- SEM) pg/ml at 30 min. In the ibuprofen pretreated group no significant changes occurred in hemodynamic measurements or concentrations of prostanoids. The inhibition of 6-keto-PGF1 alpha and its associated hemodynamic changes in the treatment group, but not in the placebo group, confirms the hypothesis that prostacyclin is the mediator of the mesenteric traction response in abdominal aortic surgery.

Topics: 6-Ketoprostaglandin F1 alpha; Abdomen; Adult; Aged; Aorta; Double-Blind Method; Epoprostenol; Female; Flushing; Hemodynamics; Humans; Ibuprofen; Male; Middle Aged; Premedication; Prospective Studies; Randomized Controlled Trials as Topic; Thromboxane B2

Levels of immunoreactive 6-oxo-prostaglandin F1 alpha (6-oxo-PGF1 alpha) and thromboxane B2 (TXB2) were measured in peripheral venous plasma in a group of volunteers and non-insulin dependent diabetic patients (NIDDS). Levels of these eicosanoids were close to the limit of sensitivity of the radioimmunoassays and consequently data are reported as maximal values. Basal plasma levels of 6-oxo-PGF1 alpha did not exceed 5 pg/ml in either group and maximal levels of immunoreactive TXB2 were 125 +/- 14 and 128 +/- 8 pg/ml for volunteers and NIDDS respectively. Attempts to elicit peripheral vascular prostacyclin biosynthesis in volunteers by using forearm ischaemia produced no increase in plasma 6-oxo-PGF1 alpha levels. Measurement of the combined plasma levels of 6-oxo-PGF1 alpha, 13,14-dihydro-6-oxo-PGF1 alpha, 13,14-dihydro-6,15-dioxo-PGF1 alpha and 6-oxo-PGE1 indicated that these were also low (less than 5 pg/ml) and that failure to demonstrate increased 6-oxo-PGF1 alpha levels was unlikely to have arisen from metabolism of prostacyclin to one or more of these metabolites. Measurement of 6-oxo-PGF1 alpha and TXB2 in peripheral venous plasma before and during chloropropamide alcohol flushing (CPAF) did not provide evidence for a role for these eicosanoids in the etiology of this phenomenon. These findings point to the need for a reappraisal of studies that have described altered plasma levels of 6-oxo-PGF1 alpha and TXB2 in CPAF and other pathophysiological conditions in man.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Chlorpropamide; Diabetes Mellitus, Type 2; Ethanol; Female; Flushing; Forearm; Humans; Indomethacin; Ischemia; Male; Middle Aged; Radioimmunoassay; Thromboxane B2; Thromboxanes

Mesenteric traction syndrome consists of sudden tachycardia, hypotension, and cutaneous hyperemia, and frequently occurs during mesenteric traction in patients undergoing abdominal aortic aneurysm (AAA) reconstructive surgery. The etiology and clinical impact of this phenomenon are unknown, but the symptoms suggest a release of vasoactive materials from the mesenteric vascular bed. Thirty-one patients who underwent AAA surgery were studied. Mesenteric traction was accompanied by a decrease in systolic (p = 0.005) and diastolic (p less than 0.05) blood pressures, and in systemic vascular resistance (p less than 0.005), and was accompanied by an increase in heart rate (HR) (p less than 0.005), and cardiac output (p = 0.01). These hemodynamic changes coincided with an increase (p less than 0.001) in plasma concentrations of 6-keto-prostaglandin F1 (6-K-PGF1). No apparent change was found in prostaglandin E2, thromboxane B2, and histamine concentrations. The concentration of 6-K-PGF1 was correlated with diastolic blood pressure (r = -0.52, p less than 0.005) and HR (r = 0.65, p less than 0.001). Cutaneous hyperemia was observed in 58% of the patients. In an additional six patients, who had taken aspirin daily before AAA surgery, no significant changes were observed in the hemodynamic measurements or 6-K-PGF1 concentrations. These data suggest that mesenteric traction syndrome may be mediated at least in part by a selective release of prostacyclin.

Topics: 6-Ketoprostaglandin F1 alpha; Aged; Aged, 80 and over; Anesthesia, General; Aortic Aneurysm; Epoprostenol; Female; Flushing; Humans; Hypotension; Intraoperative Complications; Male; Mesenteric Arteries; Mesenteric Veins; Middle Aged; Syndrome; Tachycardia; Thromboxane B2