Organ failure in sepsis

Effect of low-dose hydrocortisone and inhaled nitric oxide on inflammatory mediators and local pulmonary metalloproteinases activity in LPS-induced sepsis in piglets

Hospital mortality in sepsis varies between 30-45%. It has been shown that administration of inhaled nitric oxide (iNO) and intravenous corticosteroid in a porcine endotoxemia model attenuated the systemic inflammatory response. We explored the anti-inflammatory effect of a double-treatment strategy (iNO + low-dose steroid) on the lungs in a long-term porcine endotoxic shock model. As metalloproteinases (MMPs) are involved in the initiation of multiple organ dysfunction in septic shock, we evaluated the influence of this combination therapy on MMP2 and MMP9 activity and proIL-1β maturation. A shock-like condition was established in 23 animals by continuous infusion of E. coli lipopolysaccharide (LPS) for 10 h. Then the animals were observed for 10 h. Twelve pigs received iNO and hydrocortisone (iNO treatment started 3 h after the initial LPS infusion and continued until the end of the experiment). Eleven pigs were controls. Pigs treated with iNO and hydrocortisone displayed less inflammatory infiltrates in the lungs than the controls and a lower level of IL-1β. The proMMP2 was significantly decreased in the iNO and hydrocortisone group. The amount of an active MMP9 (~ 60 kDa) was decreased in the iNO and hydrocortisone group. Total gelatinolytic activity was lower in the iNO and hydrocortisone group. Reduced MMP activity was accompanied by a 2.5-fold decrease of the active IL-1β form (17 kDa) in the pulmonary tissue of iNO combined with hydrocortisone exposed pigs. We demonstrated that in a porcine endotoxemia model the NO inhalation combined with intravenous hydrocortisone led to the attenuation of the inflammatory cascade induced by bacterial LPS. The decrease in pulmonary MMPs activities was accompanied by reduced proIL-1β processing.

Tp-Te Interval and Tp-Te/QT Ratio Are Valuable Tools in Predicting Poor Outcome in Sepsis Patients

Objective

About 50% of patients with sepsis have different degrees of myocardial inhibition, known as sepsis-induced myocardial dysfunction (SMD), which increases the mortality rate of sepsis. Tp-Te interval and Tp-Te/QT ratio reflect ventricular transmural dispersion repolarization (TDR), and have good predictive value for death in patients with heart disease. This study aimed to investigate the prognostic value of Tp-Te and Tp-Te/QT in patients with sepsis.

Methods

The current study included a total of 625 participants: 201 patients with sepsis, 213 patients with heart failure, and 211 healthy participants. According to the severity and outcome, the patients with sepsis were divided into the sepsis group and the septic shock group, and the death group and the survival group to explore the differences of indicators among subgroups of sepsis. The ROC curve was used to analyze the predictive value of the indicators for deaths of patients with sepsis and calculate the cutoff point. Then, we investigated the incidence of arrhythmia in patients with sepsis with different TDR. The correlation between Tp-Te/QT and the commonly used predictive indicators in ICU was also discussed.

Results

(1) Tp-Te and Tp-Te/QT in patients with sepsis and heart failure (HF) were significantly higher than the control group (p < 0.01). (2) Compared with patients with sepsis, the increase of Tp-Te and Tp-Te/QT is more prominent in patients with HF. Especially, the increase of the Tp-Te/QT was statistically significant (p < 0.001). (3) compared with patients with sepsis (no shock), the Tp-Te, Tp-Te/QT, and SOFA were increased in patients with septic shock (p < 0.05). (4) In the death group, Tp-Te /QT, SOFA, and Apache-II were higher; LVEF was lower than the survival group (p < 0.05). (5) ROC curves showed that Tp-Te/QT, SOFA, and LVEF have predictive values for death (p < 0.05; AUC = 0.808, 0.716, 0.412). The cutoff point of Tp-Te/QT was 0.32. (6) The incidence of arrhythmia is different in patients with sepsis with different TDR. (7) There is a significant correlation between Tp-Te/QT and SOFA (p < 0.001, r = 0.79).

Conclusion

TDR in patients with sepsis is significantly increased, which was between healthy population and patients with HF. Tp-Te and Tp-Te/QT are effective indicators to reflect the severity and poor outcome of patients with sepsis.

Recent advances in understanding and managing sepsis

The last two to three years provided several “big steps” regarding our understanding and management of sepsis. The increasing insight into pathomechanisms of post-infectious defense led to some new models of host response. Besides hyper-, hypo-, and anti-inflammation as the traditional approaches to sepsis pathophysiology, tolerance and resilience were described as natural ways that organisms react to microbes. In parallel, huge data analyses confirmed these research insights with a new way to define sepsis and septic shock (called “Sepsis-3”), which led to discussions within the scientific community. In addition to these advances in understanding and defining the disease, follow-up protocols of the initial “sepsis bundles” from the Surviving Sepsis Campaign were created; some of them were part of quality management studies by clinicians, and some were in the form of mandatory procedures. As a result, new “bundles” were initiated with the goal of enabling standardized management of sepsis and septic shock, especially in the very early phase. This short commentary provides a brief overview of these two major fields as recent hallmarks of sepsis research.

High performance of a unique mesoporous polystyrene-based adsorbent for blood purification

A multi-functional polystyrene based adsorbent (NKU-9) with a unique mesoporous and a high surface area was prepared by suspension polymerization for removal of therapeutic toxins in blood purification. The adsorbent produced had an almost equal amount of mesopore distribution in the range from 2 to 50 nm. The adsorption of serum toxins with different molecular weights were examined by in vitro adsorption assays and compared with some clinical currently used adsorbents such as HA-330, Cytosorb and BL-300 which are produced by China, America and Japan, respectively. Test results indicated that the adsorption rate for pentobarbital by NKU-9 was 81.24% which is nearly as high as HA-330 (81.44%). The latter adsorbent is currently used for acute detoxification treatment in China. To reach adsorption equilibrium, NKU-9 was faster than HA-330, which implies short treatment time. For the removal of middle molecular toxins such as β2-microglobulin (98.88%), NKU-9 performed better adsorptive selectivity than Cytosorb (92.80%). In addition, NKU-9 showed high performance for the removal of albumin-bound toxins (e.g., bilirubin), and its adsorption rate for total bilirubin (80.79%) in plasma was 8.4% higher than that of anion exchange resin BL-300 which is currently used to eliminate bilirubin in clinic. Therefore, our results indicate that the newly developed adsorbent with a wide distribution and almost equal amount of mesopores is a multifunctional adsorbent for high efficient removal of serum toxins with different molecular weights which might be an excellent blood purification adsorbent especially to treat diseases that conventional medical methods are low or not efficient.

Agents to reduce cytokine storm

The increasing insight into pathomechanisms of dysregulated host response in several inflammatory diseases led to the implementation of the term “cytokine storm” in the literature more than 20 years ago. Direct toxic effects as well as indirect immunomodulatory mechanisms during cytokine storm have been described and were the basis for the rationale to use several substances and devices in life-threatening infections and hyperinflammatory states. Clinical trials have been performed, most of them in the form of minor, investigator-initiated protocols; major clinical trials focused mostly on sepsis and septic shock. The following review tries to summarize the background, pathophysiology, and results of clinical investigations that had implications for the development of therapeutic strategies and international guidelines for the management of hyperinflammation during syndromes of cytokine storm in adult patients, predominantly in septic shock.

Effect of induced mild hypothermia on two pro-inflammatory cytokines and oxidative parameters during experimental acute sepsis

This study aimed to determine the effect of induced mild hypothermia (34°C) on the production of two cytokines (interleukin (IL-6) and tumor necrosis factor (TNF)alpha) and reactive nitrogen and oxygen species in plasma and the heart of acutely septic rats. After anesthesia and in conditions of normothermia (38°C) or mild hypothermia (34°C), acute sepsis was induced by cecal ligation and perforation. For each temperature three groups were formed: (1) baseline (blood sample collected at T0 hour), (2) sham (blood sample at T4 hours) and (3) septic (blood sample at T4 hours). At either temperature sepsis induced a significant increase in plasma IL-6, TNF-alpha and HO• concentration, compared with the sham groups (P≤0.016). Compared with the normothermic septic group, septic rats exposed to mild hypothermia showed a mild decrease in TNF-alpha concentration (104±50 pg/ml vs. 215±114 pg/ml; P>0.05) and a significant decrease in IL-6 (1131±402 pg/ml vs. 2494±691 pg/ml, P=0.038). At either temperature sepsis induced no enhancement within the heart of lipoperoxidation (malondialdehyde content) or antioxidant activities (superoxide dismutase and catalase). In conclusion, during acute sepsis, induced mild hypothermia appears to reduce some pro-inflammatory and oxidative responses. This may, in part, explain the beneficial effect of hypothermia on survival duration of septic rats.

Immunoglobulins in adult sepsis and septic shock

For more than 30 years, intravenously administered immunoglobulins (ivIG) have been used to treat primary and secondary syndromes of immune deficiency. Increasing insight into pathomechanisms of severe sepsis and septic shock have led to the implementation of ivIG therapy in the strategies for adjunctive therapy in sepsis in both adults and children. Direct antitoxic effects, as well as indirect immunomodulatory mechanisms of ivIG have been described in the literature and were the basis for the rationale to use these substances in life-threatening infections and hyperinflammatory states. Several clinical trials have been performed, most of them as minor, investigator-initiated protocols. This review summarizes the results of clinical investigations and systematic meta-analyses that have implications for the development of therapeutic strategies, and international guidelines for the management of severe sepsis and septic shock in adult patients.