Damage-associated molecular patterns in resuscitated hemorrhagic shock are mitigated by peritoneal fluid administration

Phase I clinical trial of the feasibility and safety of direct peritoneal resuscitation in liver transplantation

BACKGROUND

Direct peritoneal resuscitation (DPR) is associated with improved outcomes in trauma. Animal models suggest DPR has favorable effects on the liver. We sought to evaluate its safety and assess for improved outcomes in liver transplantation (LT).

METHODS

LT patients with renal dysfunction and/or obesity were enrolled in a phase-I clinical trial. DPR lasted 8-24 ​h depending on postoperative disposition. Primary outcome was percent of patients completing DPR. Secondary outcomes evaluated complications. Controls with either obesity (control-1) or both risk factors (obesity ​+ ​renal dysfunction, control-2) were analyzed.

RESULTS

Fifteen patients were enrolled (seven with both criteria and eight with obesity alone). DPR was completed in 87 ​% of patients, with one meeting stopping criteria. Controls included 45 (control-1) and 24 (control-2) patients. Return to operating room, graft loss, and late infections were lower with DPR.

CONCLUSION

DPR appears to be safe in closed abdomens following LT, warranting a follow-up phase-II trial to assess efficacy.

Effects and Mechanisms of Peritoneal Resuscitation on Acute Kidney Injury After Severe Burns in Rats

INTRODUCTION

Acute kidney injury (AKI) is a common complication in severe burn patients with poor prognosis and high mortality. Reduced kidney perfusion induced by the decreased effective circulating blood volume after severe burn is a common cause of AKI. Routine intravenous resuscitation (IR) is difficult or delayed in extreme conditions such as war and disaster sites. Peritoneal resuscitation (PR) is a simple, rapid resuscitation strategy via a puncture in the abdominal wall. This study investigated whether PR is a validated resuscitation strategy for AKI after severe burns in rats and explored its mechanisms.

MATERIALS AND METHODS

Eighty Sprague-Dawley rats were randomized into four groups: (1) sham group; (2) IR group, which was characterized by the full thickness burn of 50% of the total body surface area received IR immediately post-injury; (3) early PR group, in which rats with the same burn model received PR immediately post-injury; and (4) delayed resuscitation (DR) group, in which rats with the same burn model received no resuscitation within 3-hour post-injury. PR and DR groups animals received IR after 3-hour post-injury. The survival rate, mean arterial pressure, renal histopathology, renal function, indicators of renal injury, and renal hypoxia-inducible factor-1α and NADPH oxidase 4 (NOX4) proteins of rats were measured at 3 h, 12 h, and 24 h post-injury.

RESULTS

Compared with rats in the DR group, rats in the PR group had a significantly improved survival rate (100% vs. 58.3% at 24 h, P = 0.0087), an increased mean arterial pressure (92.6 ± 6.6 vs. 65.3 ± 10.7, 85.1 ± 5.7 vs. 61.1 ± 6.9, 90.1 ± 8.7 vs. 74.9 ± 7.4 mmHg, at 3 h, 12 h, and 24 h, P < 0.01), a reduced renal water content rate (51.6% ± 5.0% vs. 70.1% ± 6.8%, 57.6% ± 7.7% vs. 69.5% ± 8.7%, at 12 h and 24 h, P < 0.01), attenuated histopathological damage, reduced serum creatinine expression (36.36 ± 4.27 vs. 49.98 ± 2.42, 52.29 ± 4.31 vs. 71.32 ± 5.2, 45.25 ± 2.55 vs. 81.15 ± 6.44 μmol/L, at 3 h, 12 h, and 24 h, P < 0.01) and BUN expression (7.62 ± 0.30 vs. 10.80 ± 0.58, 8.61 ± 0.32 vs. 28.58 ± 1.99, 8.09 ± 0.99 vs. 20.95 ± 1.02 mmol/L, at 3 h, 12 h, and 24 h, P < 0.01), increased kidney injury markers neutrophil gelatinase-associated lipocalin expression (95.09 ± 7.02 vs. 101.75 ± 6.23, 146.77 ± 11.54 vs. 190.03 ± 9.87, 112.79 ± 15.8 vs. 194.43 ± 11.47 ng/mL, at 3 h, 12 h, and 24 h, P < 0.01) and cystatin C expression (0.185 ± 0.006 vs. 0.197 ± 0.006, 0.345 ± 0.036 vs. 0.382 ± 0.013, 0.297 ± 0.012 vs. 0.371 ± 0.028 ng/mL, at 3 h, 12 h, and 24 h, P < 0.01), and reduced renal hypoxia-inducible factor-1α and NADPH oxidase 4 protein expression (P < 0.01). There was no significant difference between rats in the PR group and the IR group in the above indicators.

CONCLUSIONS

Early PR could protect severe burn injury rats from AKI. It may be an alternative resuscitation strategy in severe burn injury when IR cannot be achieved.

Facing Trauma and Surgical Emergency in Space: Hemorrhagic Shock

Although the risk of trauma in space is low, unpredictable events can occur that may require surgical treatment. Hemorrhage can be a life-threatening condition while traveling to another planet and after landing on it. These exploration missions call for a different approach than rapid return to Earth, which is the policy currently adopted on the International Space Station (ISS) in low Earth orbit (LEO). Consequences are difficult to predict, given the still scarce knowledge of human physiology in such environments. Blood loss in space can deplete the affected astronaut's physiological reserves and all stored crew supplies. In this review, we will describe different aspects of hemorrhage in space, and by comparison with terrestrial conditions, the possible solutions to be adopted, and the current state of the art.

Mechanisms and prevention of intestinal barrier function damage in traumatic hemorrhagic shock

The intestinal barrier is composed of mechanical barrier, chemical barrier, immune barrier, and microbial barrier, which has an important role in defense against microbial invasion. The components of intestinal barrier coordinate with each other under physiological conditions to maintain the homeostasis of intestinal internal and external environment. In traumatic hemorrhagic shock, intestinal barrier function is prone to be impaired by intestinal hypoperfusion, intestinal ischemia-reperfusion injury, and many other factors. Bacterial translocation and endotoxin entry into the blood may occur, leading to enterogenic infection, multiple organ dysfunction, and even death. At present, there are many conceptual updates and technical progress on the mechanisms, prevention, and treatment of intestinal barrier function injury in traumatic hemorrhagic shock both at home and abroad. This paper intends to make a literature review in this field based on the previous research of our team, in order to provide a systematic and comprehensive theoretical system for the clinical prevention and treatment of post-traumatic intestinal dysfunction related diseases.

The role of direct peritoneal resuscitation in the treatment of hemorrhagic shock after trauma and in emergency acute care surgery: a systematic review

PURPOSE

Direct peritoneal resuscitation (DPR) has been used to help preserve microcirculation by reversing vasoconstriction and hypoperfusion associated with the pathophysiological process of shock, which can occur despite appropriate intravenous resuscitation. This approach depends on infusing a hyperosmolar solution intraperitoneally via a percutaneous catheter with the tip ending near the pelvis or the root of the mesentery. The abdomen is usually left open with a negative pressure abdominal dressing to continuously evacuate the infused dialysate. Hypertonicity of the solution triggers visceral vasodilation to help maintain blood flow, even during shock, and is also associated with reduced local inflammatory cytokines and other mediators, preservation of endothelial cell function, and mitigation of organ edema and necrosis. It also has a direct effect on liver perfusion and edema, more rapidly corrects electrolyte abnormalities compared to intravenous resuscitation alone, and may requireless intravenous fluid to stabilize blood pressure, all of which shortens the time required to close patients' abdomen.

METHODS

An online query using the search term "direct peritoneal resuscitation" was carried out in PubMed, MEDLINE and SciELO, limited to publications indexed from January 2014 to June 2020. Of the 20 articles returned, full text was able to be obtained for 19. A manual review of included articles' references was resulted in the addition of 1 article, for a total of 20 included articles.

RESULTS

The 20 articles were comprised of 15 animal studies, 4 clinical studies,and 1 expert opinion. The benefits include both local and possibly systemic effects on perfusion, hypoxia, acidosis, and inflammation, and are associated with improved outcomes and reduced complications.

CONCLUSION

DPR shows promise in patients with hemorrhagic shock, septic shock, and other conditions resulting in an open abdomen after damage control laparotomy.

Tenascin-C Participates Pulmonary Injury Induced by Paraquat Through Regulating TLR4 and TGF-β Signaling Pathways

This study was conducted to investigate the role of Tenascin-C (TNC) in paraquat (PQ)-induced lung injury in vivo and in vitro and explore its related mechanism during this process. Six- to eight-week-old male C57BL/6 mice were injected with 30 mg/kg PQ by intraperitoneal injection and sacrificed on 2 days, 7 days, 14 days, and 28 days after PQ administration. In vivo, we detected the expression of TNC at all time points of lung tissues in mice by reverse transcription-quantitative-polymerase chain reaction, western blotting, and immunohistochemistry. Expression of TLR4, NF-κB p65, TGF-β1, and α-SMA in lung tissues have also been tested. In vitro, siRNA was used to knock down TNC expression in A549 cells and TLR4, NF-κB p65, and TGF-β1 expressions were examined after PQ exposure. TNC expression increased in both lung tissues of mice model and A549 cells after PQ administration. In vivo, TNC mostly located at the extracellular matrix of thickened alveolar septum, especially at sites of injury, together with the increasing of TLR4, NF-κB p65, TGF-β1, and α-SMA. In vitro, PQ exposure also increased the expressions of TLR4, NF-κB p65, and TGF-β1 in A549 cells, but knocking down TNC gene expression obviously down-regulated the expressions of TLR4, NF-κB p65, NF-κB Pp65, and TGF-β1. The results of this study demonstrate, for the first time, that TNC participates in the development of lung injury induced by PQ poisoning. The role of TNC in this process is closely related to TLR4 and TGF-β signaling pathways.

Role of DAMPs in respiratory virus-induced acute respiratory distress syndrome-with a preliminary reference to SARS-CoV-2 pneumonia

When surveying the current literature on COVID-19, the "cytokine storm" is considered to be pathogenetically involved in its severe outcomes such as acute respiratory distress syndrome, systemic inflammatory response syndrome, and eventually multiple organ failure. In this review, the similar role of DAMPs is addressed, that is, of those molecules, which operate upstream of the inflammatory pathway by activating those cells, which ultimately release the cytokines. Given the still limited reports on their role in COVID-19, the emerging topic is extended to respiratory viral infections with focus on influenza. At first, a brief introduction is given on the function of various classes of activating DAMPs and counterbalancing suppressing DAMPs (SAMPs) in initiating controlled inflammation-promoting and inflammation-resolving defense responses upon infectious and sterile insults. It is stressed that the excessive emission of DAMPs upon severe injury uncovers their fateful property in triggering dysregulated life-threatening hyperinflammatory responses. Such a scenario may happen when the viral load is too high, for example, in the respiratory tract, "forcing" many virus-infected host cells to decide to commit "suicidal" regulated cell death (e.g., necroptosis, pyroptosis) associated with release of large amounts of DAMPs: an important topic of this review. Ironically, although the aim of this "suicidal" cell death is to save and restore organismal homeostasis, the intrinsic release of excessive amounts of DAMPs leads to those dysregulated hyperinflammatory responses-as typically involved in the pathogenesis of acute respiratory distress syndrome and systemic inflammatory response syndrome in respiratory viral infections. Consequently, as briefly outlined in this review, these molecules can be considered valuable diagnostic and prognostic biomarkers to monitor and evaluate the course of the viral disorder, in particular, to grasp the eventual transition precociously from a controlled defense response as observed in mild/moderate cases to a dysregulated life-threatening hyperinflammatory response as seen, for example, in severe/fatal COVID-19. Moreover, the pathogenetic involvement of these molecules qualifies them as relevant future therapeutic targets to prevent severe/ fatal outcomes. Finally, a theory is presented proposing that the superimposition of coronavirus-induced DAMPs with non-virus-induced DAMPs from other origins such as air pollution or high age may contribute to severe and fatal courses of coronavirus pneumonia.