The incomplete puzzle of vasoactive medication in (abdominal) sepsis

Adrenergic Effect on Cytokine Release After Ex Vivo Healthy Volunteers' Whole Blood LPS Stimulation

Catecholamines are molecules with immunomodulatory properties in health and disease. Several studies showed the effect of catecholamines when administered to restore hemodynamic stability in septic patients. This study investigates the effect of norepinephrine and dobutamine on whole blood cytokine release after ex vivo lipopolysaccharide (LPS) stimulation. Whole blood collected from healthy individuals was stimulated with LPS, in the presence of norepinephrine or dobutamine at different concentrations, with or without metoprolol, a β1 receptor antagonist. Cytokine measurement was performed in isolated cell culture supernatants with ELISA. Results are expressed as mean ± SEM and compared with Mann-Whitney rank-sum test. Both norepinephrine and dobutamine significantly reduced TNF-α and IL-6 production after ex vivo LPS stimulation of whole blood in a dose-dependent manner, and this effect was partially reversed by the presence of metoprolol. Norepinephrine and dobutamine reduce the LPS-induced production of pro-inflammatory cytokines, thus possibly contributing to altered balance between the inflammatory and anti-inflammatory responses, which are vital for a successful host response to severe disease, shock, and sepsis.

Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

OBJECTIVE

It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chiús classification to grade the histopathological damage.

METHODS

We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ± standard deviation and compared the baseline and maximum values for each marker using Student's t-test.

RESULTS

The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group.

CONCLUSION

For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion.

Systematic review and pooled estimates for the diagnostic accuracy of serological markers for intestinal ischemia

BACKGROUND

Intestinal ischemia is a potentially catastrophic abdominal emergency that presents a significant diagnostic challenge in the critical care setting. We performed a systematic review of the literature to define the diagnostic accuracy of serological markers of intestinal ischemia.

METHODS

Observational studies on the performance of markers of intestinal ischemia were identified within the MEDLINE and EMBASE electronic databases. All studies from which it was possible to derive true positive, false positive, false negative, and true negative results were included. A random-effects model was used to calculate the pooled estimates of diagnostic accuracy.

RESULTS

A total of 20 articles examining 18 different serological markers were identified that met the inclusion criteria. The global measures of test performance (diagnostic odds ratio and area under the summary receiver operating characteristic curve) for markers investigated in three or more studies were D-lactate (10.75 and 0.86, respectively), glutathione S-transferase (GST; 8.82 and 0.87, respectively), intestinal fatty-acid binding protein (i-FABP; 7.62 and 0.78, respectively), and D-dimer (5.77 and 0.53, respectively).

CONCLUSIONS

The performance of the currently available serological markers is suboptimal for routine clinical use, but novel markers of intestinal ischemia such as D-lactate, GST, and i-FABP may offer improved diagnostic accuracy. The early diagnosis of intestinal ischemia remains a challenge, and further research is required to identify improved serological markers and to demonstrate their clinical utility in the individual patient.