thromboxane-a2 and Multiple-Organ-Failure

The role of the various cyclo-oxygenase products of arachidonic acid metabolism in the production of the pathologic, physiologic, hemodynamic, and metabolic derangements of sepsis has been reviewed and there is a wide variation in different species and with different models of sepsis. The relationship of these potential mediators cannot be definitely determined. There is much circumstantial evidence that would incriminate the various arachidonic metabolites in the production of the sepsis manifestations; however, we must keep in mind that this may only be "guilt by association." Clearly, the available evidence does suggest that there is some role played by TXA2 and PGI2 in the physiologic and hemodynamic manifestations of sepsis, but the exact role remains undetermined.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acids; Cyclooxygenase Inhibitors; Epoprostenol; Humans; Multiple Organ Failure; Prostaglandin-Endoperoxide Synthases; Shock, Septic; Thromboxane A2; Thromboxane-A Synthase

This study has shown that multiple organ failure (MOF) is one of the major causes of death in patients with severe burns. Both the plasma and visceral levels of TXB2 and the TXB2/6-keto-PGF1 alpha ratio were significantly increased. The changed plasma levels of TXB2 and the TXB2/6-keto-PGF1 alpha ratio paralleled the deterioration of the general condition in MOF patients. The circulatory platelet aggregation ratios (CPAR) in the MOF patients initially declined then dropped profoundly at 5-7 days postburn, indicating more microaggregate formation. CPK, LDH and GOT had increased markedly by 1 day, were elevated further at 2-3 days, and remained at supranormal levels for the first 7 days postburn. Degeneration, destruction, oedema, haemorrhage and thrombosis were observed in tissues from patients who died due to heart, lung, renal and hepatic failure. Clinically, 13 of the 16 MOF cases developed organ failure and 11 died between 3 and 7 days postburn. These findings confirmed that the increases of TXA2 and the TXA2/PGI2 ratio in plasma and visceral tissues can be an important factor in the genesis and development of postburn MOF.

Topics: 6-Ketoprostaglandin F1 alpha; Adolescent; Adult; Body Surface Area; Burns; Female; Humans; Male; Middle Aged; Multiple Organ Failure; Prospective Studies; Shock; Thromboxane A2

Arachidonic acid metabolites, especially thromboxane-A2 and prostacyclin, have been shown to be increased in experimental models of sepsis and the adult respiratory distress syndrome (ARDS) and play a major pathophysiologic role. This study was designed to determine if these metabolites are increased in human sepsis syndrome and if inhibition of fatty acid cyclooxygenase affects their formation and their pathophysiologic sequelae. We conducted a double-blind, placebo-controlled trial of ibuprofen (800 mg given rectally every 4 h for three doses) in 30 patients with sepsis syndrome defined by abnormal vital signs, the appearance of serious infection, and at least one major organ failure. Urinary concentrations of the metabolite of thromboxane-A2, 2,3-dinor-TxB2, and prostacyclin, 2,3-dinor-6-keto-prostaglandin F2 alpha, were elevated 10 to 20 times normal and declined to four to five times normal by 12 h after entry in the ibuprofen-treated group and remained elevated in the placebo-treated patients. The urinary concentration of TxB2 and 6-keto-prostaglandin F1 alpha, which reflect renal production of TxA2 and prostacyclin, respectively, were also increased approximately 10-fold over normal and were subsequently decreased by ibuprofen. Coincident with the reduction in metabolite levels, the ibuprofen-treated group, but not the placebo-treated group, experienced a significant decline in temperature, heart rate, and peak airway pressure, and a trend towards more rapid reversal of shock (p = 0.12).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Cyclooxygenase Inhibitors; Double-Blind Method; Epoprostenol; Humans; Ibuprofen; Multiple Organ Failure; Sepsis; Syndrome; Thromboxane A2; Time Factors

The study deals with an animal model for the problems of surgical intensive care patients. Following repeated applications of E. coli endotoxin WO 111:B4 under standard conditions, specific hemodynamic and biochemical (TNF, TXA2, PGI2, IL-6, PAF) and morphological (endothelium of the lung) alterations were detected. ARDS patterns induced by the sepsis were analyzed by high-frequency measurement of pressure and flow (385 measurements per breathing cycle). The role of the intestine in sepsis was investigated by ion-selective monitoring of surface potassium activity comparing mucosa and serosa. Every injection of endotoxin was followed by a selective increase of the potassium activity revealing relative ischemia induced by the endotoxin. The profile of the potassium levels on the surface correlates both with the cardiac output and with the prostacyclin levels. The continuous narrowing of the difference between mucosa and serosa, potassium during the period of investigation can be regarded as evidence for pathologic change in permeability fostering the septic course.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Critical Care; Epoprostenol; Escherichia coli Infections; Hemodynamics; Interleukin-6; Intestinal Mucosa; Intestines; Ion Channels; Ischemia; Lung; Microscopy, Electron; Multiple Organ Failure; Platelet Activating Factor; Postoperative Complications; Potassium; Pulmonary Gas Exchange; Respiratory Distress Syndrome; Shock, Septic; Swine; Thromboxane A2; Tumor Necrosis Factor-alpha

15 out of 68 patients with severe sepsis were examined in an early stage of shock and analyzed for objective hemodynamic and functional shock criteria. These data were correlated to endogenous plasma concentrations of the vasoactive arachidonate derivatives: prostaglandin F2 alpha (PGF2 alpha), thromboxane A2 (TXA2) and prostacyclin (PGI2). Marked differences in invasively measured data of cardiac, pulmonary and renal functions divided clinically otherwise comparable patients into group I and II. Group I was characterized by a hypodynamic response as compared to group II which was hyperdynamic. In spite of similar levels of PGF2 alpha (570 +/- 80 vs. 560 +/- 103 pg/ml) in both groups indicating a comparable state of arachidonate turnover, opposing profiles with regard to the TXA2/PGI2 ratio as measured from their stable degradation products were found (TXB2 [I]: a 740 +/- 184; TXB2 [II]: 280 +/- 75; 6-k-PGF1 alpha [I]: 260 +/- 117; 6-k-PGF1 alpha [II]: 940 +/- 190 pg/ml). It is concluded that early sepsis in man leads to variable profiles of endogenously released prostaglandins and thromboxane in which the predominance of PGI2 over TXA2 is associated with better cardiovascular performance and organ functions, and vice versa.

Topics: Adolescent; Adult; Aged; Creatinine; Dinoprost; Epoprostenol; Female; Hemodynamics; Humans; Kidney; Lung; Male; Middle Aged; Multiple Organ Failure; Prostaglandins F; Retrospective Studies; Shock, Septic; Thromboxane A2