Determination of Endotoxin-Neutralizing Capacity of Plasma in Postsurgical Patients

Abstract

In 92 patients who underwent abdominal and goiter surgery endotoxin and endotoxin-neutralizing capacity (ENC) were determined in plasma preoperatively and daily postoperatively. Endotoxin plasma levels started to increase on day 1 in patients who were laparotomized. Correspondingly ENC was reduced during the 1st postoperative week. Even on the 1st postoperative day determination of ENC made the differentiation between patients possible who showed an uneventful course and patients who developed pneumonia, pulmonary failure, or mental disorders. Furthermore the need for diuretics in order to maintain sufficient renal function was associated with lower ENC during days 1–3. Endotoxin plasma levels were significantly elevated in patients who developed pneumonia during days 1–4, whereas the occurrence of pulmonary failure was only correlated with elevated endotoxin levels on day 3. Endotoxemia was pronounced in patients needing diuretics on days 1, 4, and 5. In patients who underwent goiter surgery ENC changed significantly as found for endotoxin plasma values during the postoperative course. Determination of endotoxin and especially ENC with the use of the limulus amebocyte lysate test turned out to be a reliable method correlating with impending complications at least in postsurgical patients.

Changes in Endotoxin-Binding Proteins during Major Elective Surgery: Important Role for Soluble CD14 in Regulation of Biological Activity of Systemic Endotoxin

“…In the present study, we assessed the biological activity of the translocated endotoxin after major elective surgery. Our results demonstrated the presence of significant endotoxemia during major abdominal surgery, which is related to a loss of plasma ENC, as described previously (4). Preoperative patient plasma neutralized almost all exogenously added endotoxin, whereas postoperative plasma did not have enough capacity to neutralize the same quantity of endotoxin, resulting in postoperative loss of ENC.…”

“…Estimation of ENC. The ENC of plasma, expressed as endotoxin recovery, was measured by using the LAL test and has been recently described in detail (4). The method principally relies on the determination of the recovery of exogenously added endotoxin to plasma samples.…”

“…The endotoxin-neutralizing capacity (ENC) of plasma can be easily determined by a direct Limulus amebocyte lysate (LAL) test without heat inactivation of the inhibitors present in plasma (4). Our previous studies showed that ENC was decreased significantly during aseptic abdominal surgery, which is associated with impending complications due to infection (4).…”

“…The endotoxin-neutralizing capacity (ENC) of plasma can be easily determined by a direct Limulus amebocyte lysate (LAL) test without heat inactivation of the inhibitors present in plasma (4). Our previous studies showed that ENC was decreased significantly during aseptic abdominal surgery, which is associated with impending complications due to infection (4). Elective aseptic abdominal surgery represents a human model characterized by a significant and reproducible endotoxemia and a well-defined acute phase reaction (5,6,12,37,46).…”

Pathophysiological relevance of the CD14 receptor in surgical patients: biological activity of endotoxin is regulated by the CD14 receptor

“…The endotoxin-neutralizing capacity (ENC) of plasma can easily be determined by a direct LAL test without heat inactivation of inhibitors present in plasma. 23 This method principally relies on determining the recovery of endotoxin exogenously added to plasma samples. In contrast to the estimation of endogenous endotoxin, inactivation of the plasma samples was omitted.…”