Clinical year in review 2014: critical care medicine

Pain management in surgical intensive care patients: A retrospective observational research

Sepsis and septic shock are the most common causes of death in non-cardiac surgical intensive care units (ICU). Adequate analgesia is essential to achieve positive outcomes. There were differences in pain management between patients with and without sepsis or septic shock. The release of inflammatory mediators, especially cytokines, in sepsis or septic shock decreases the pain threshold. Septic intensive care patients probably require higher doses of opioids than do non-septic patients. A retrospective observational study was carried out in an anesthesiologic intensive care unit from January 1, 2014 to June 30, 2016. Patients were divided into 4 groups according to the following criteria: sepsis ("yes/no" and communication ability "yes/no"). After adjusting for the number of cases using the pairing method, a total of 356 patients were recruited. The endpoint of our study was defined as the "total opioid dose". Statistical evaluations were performed using t tests and 2-factor analysis of variance. There was a significant difference in opioid doses between communicative and non-communicative ICU patients F(1, 352) = 55.102, P < .001). This effect was observed in the ICU patients with and without sepsis. The mean sufentanil dose was significantly higher in non-communicative patients than in communicative patients group (E(1, 352) = 51.435, P < .001, partial ƞ2 = 0.144). The effect of higher opioid- (F(1, 352) = 1.941, P = .161) and sufentanil (F(1, 352) = 1.798, P = .342) requirement was not statistically significant due to sepsis. The hypothesis that sepsis decreases the pain threshold could not be proven in this study. The effect of a higher opioid requirement is not directly caused by sepsis but by communication ability. Furthermore, we were able to show through our investigations and especially through the data of the pain recording instruments that the septic and non-septic intensive care patients receive sufficient pain therapy treatment in our ICU. Regular pain evaluations should be performed on patients in the ICUs who are able to communicate and those who are not.

Emodin Protects Sepsis Associated Damage to the Intestinal Mucosal Barrier Through the VDR/ Nrf2 /HO-1 Pathway

Aims: Emodin is an anthraquinone extracted from Polygonum multiflorum, which has potential anti-inflammatory and anti-oxidative stress effects. However, the possible protective mechanism of emodin is unclear. The purpose of this study was to investigate the protective mechanism of emodin against cecal ligation and puncture and LPS-induced intestinal mucosal barrier injury through the VDR/ Nrf2 /HO-1 signaling pathway.

Methods: We established a mouse model of sepsis by cecal ligation and puncture (CLP), and stimulated normal intestinal epithelial cells with lipopolysaccharide (LPS). VDR in cellswas down-regulated by small interfering ribonucleic acid (siRNA) technology.Mice were perfused with VDR antagonists ZK168281 to reduce VDR expression and mRNA and protein levels of VDR and downstream molecules were detected in cells and tissue. Inflammation markers (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6)) and oxidative stress markers (superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione (GSH)) were measured in serum and intestinal tissueby enzym-linked immunosorbent assay. The expression of VDR in intestinal tissue was detected by immunofluorescence. Histopathological changes were assessed by hematoxylin and eosin staining.

Results: In NCM460 cells and animal models, emodin increased mRNA and protein expression of VDR and its downstream molecules. In addition, emodin could inhibit the expressions of TNF-α, IL-6 and MDA in serum and tissue, and increase the levels of SOD and GSH. The protective effect of emodin was confirmed in NCM460 cells and mice, where VDR was suppressed. In addition, emodin could alleviate the histopathological damage of intestinal mucosal barrier caused by cecal ligation and puncture.

Conclusion: Emodin has a good protective effect against sepsis related intestinal mucosal barrier injury, possibly through the VDR/ Nrf2 /HO-1 pathway.

Emodin attenuates acute lung injury in Cecal-ligation and puncture rats

Acute lung injury (ALI) is a major cause of sepsis-induced acute respiratory failure. Emodin has been considered to play a protective role for acute lung edema in cecal ligation and puncture (CLP)-induced sepsis model. In this study we aimed to investigate whether emodin could improve CLP-induced lung sepsis via regulating aquaporin (AQP) and tight junction (TJ), inflammatory factors, and pulmonary apoptosis. The results showed that sepsis-induced pulmonary pathological changes were significantly improved after emodin treatment. Emodin was found to upregulate AQP and TJ expression in the CLP model. Meanwhile, inflammatory cytokine release and pulmonary apoptosis was remarkably reduced after emodin treatment in lung sepsis. Our data demonstrated that emodin could suppresse inflammation, restore pulmonary epithelial barrier and reduce mortality in CLP-induced ALI, suggesting the potential therapeutic application of emodin in sepsis.

Carbon Monoxide-Releasing Molecule-2 Reduces Intestinal Epithelial Tight-Junction Damage and Mortality in Septic Rats

Objective

Damage to intestinal epithelial tight junctions plays an important role in sepsis. Recently we found that Carbon Monoxide-Releasing Molecule-2 (CORM-2) is able to protect LPS-induced intestinal epithelial tight junction damage and in this study we will investigate if CORM-2 could protect intestinal epithelial tight junctions in the rat cecal ligation and puncture (CLP) model.

Materials and Methods

The CLP model was generated using male Sprague-Dawley (SD) rats according to standard procedure and treated with CORM-2 or inactive CORM-2 (iCORM-2), 8 mg/kg, i.v. immediately after CLP induction and euthanized after 24h or 72h (for mortality rate only). Morphological changes were investigated using both transmission electron and confocal microscopy. The levels of important TJ proteins and phosphorylation of myosin light chain (MLC) were examined using Western blotting. Cytokines, IL-1β and TNF-α were measured using ELISA kits. The overall intestinal epithelial permeability was evaluated using FD-4 as a marker.

Results

CORM-2, but not iCORM-2, significantly reduced sepsis-induced damage of intestinal mucosa (including TJ disruption), TJ protein reduction (including zonula occludens-l (ZO-1), claudin-1 and occludin), MLC phosphorylation and proinflammatory cytokine release. The overall outcomes showed that CORM-2 suppressed sepsis-induced intestinal epithelial permeability changes and reduced mortality rate of those septic rats.

Conclusions

Our data strongly suggest that CORM-2 could be a potential therapeutic reagent for sepsis by suppressing inflammation, restoring intestinal epithelial barrier and reducing mortality.