Measurement of 6-keto-PGF_1α and thromboxane B₂ levels in critically ill surgical patients

Systemic arterial and mixed venous plasma concentrations of 6-keto-PGF_1α and TxB₂ were measured by radioimmunoassay in 63 critically ill patients with major trauma (n = 20) or sepsis (n = 43). Patients undergoing elective catheterization procedures served as controls (n = 10). Arterial and mixed venous 6-keto-PGF_1α and TxB₂ levels were significantly elevated in patients with recent major trauma or active sepsis. The 6-keto-PGF_1α levels were found to be significantly elevated in the non-survivors and in patients with hepatic failure. The presence of severe pulmonary failure was not associated with increased levels of either 6-keto-PGF_1α or TxB₂. Comparison of arterial and mixed plasma samples did not demonstrate increased pulmonary release of either compound. Increased eicosanoid production may account, in part, for the local vascular and humoral responses to tissue injury or infection.