Protectin conjugates in tissue regeneration 1 alleviates sepsis-induced acute lung injury by inhibiting ferroptosis.

BACKGROUND: Acute lung injury (ALI) is a common and serious complication of sepsis with high mortality. Ferroptosis, categorized as programmed cell death, contributes to the development of lung injury. Protectin conjugates in tissue regeneration 1 (PCTR1) is an endogenous lipid mediator that exerts protective effects against multiorgan injury. However, the role of PCTR1 in the ferroptosis of sepsis-related ALI remains unknown. METHODS: A pulmonary epithelial cell line and a mouse model of ALI stimulated with lipopolysaccharide (LPS) were established in vitro and in vivo. Ferroptosis biomarkers, including ferrous (Fe2+), glutathione (GSH), malondialdehyde (MDA) and 4-Hydroxynonenal (4-HNE), were assessed by relevant assay kits. Glutathione peroxidase 4 (GPX4) and prostaglandin-endoperoxide synthase 2 (PTGS2) protein levels were determined by western blotting. Lipid peroxides were examined by fluorescence microscopy and flow cytometry. Cell viability was determined by a CCK-8 assay kit. The ultrastructure of mitochondria was observed with transmission electron microscopy. Morphology and inflammatory cytokine levels predicted the severity of lung injury. Afterward, related inhibitors were used to explore the potential mechanism by which PCTR1 regulates ferroptosis. RESULTS: PCTR1 treatment protected mice from LPS-induced lung injury, which was consistent with the effect of the ferroptosis inhibitor ferrostatin-1. PCTR1 treatment decreased Fe2+, PTGS2 and lipid reactive oxygen species (ROS) contents, increased GSH and GPX4 levels and ameliorated mitochondrial ultrastructural injury. Administration of LPS or the ferroptosis agonist RSL3 resulted in reduced cell viability, which was rescued by PCTR1. Mechanistically, inhibition of the PCTR1 receptor lipoxin A4 (ALX), protein kinase A (PKA) and transcription factor cAMP-response element binding protein (CREB) partly decreased PCTR1 upregulated GPX4 expression and a CREB inhibitor blocked the effects ofPCTR1 on ferroptosis inhibition and lung protection. CONCLUSION: This study suggests that PCTR1 suppresses LPS-induced ferroptosis via the ALX/PKA/CREB signaling pathway, which may offer promising therapeutic prospects in sepsis-related ALI.

Effect of Regional vs General Anesthesia on Incidence of Postoperative Delirium in Older Patients Undergoing Hip Fracture Surgery: The RAGA Randomized Trial.

Importance: In adults undergoing hip fracture surgery, regional anesthesia may reduce postoperative delirium, but there is uncertainty about its effectiveness. Objective: To investigate, in older adults undergoing surgical repair for hip fracture, the effects of regional anesthesia on the incidence of postoperative delirium compared with general anesthesia. Design, Setting, and Participants: A randomized, allocation-concealed, open-label, multicenter clinical trial of 950 patients, aged 65 years and older, with or without preexisting dementia, and a fragility hip fracture requiring surgical repair from 9 university teaching hospitals in Southeastern China. Participants were enrolled between October 2014 and September 2018; 30-day follow-up ended November 2018. Interventions: Patients were randomized to receive either regional anesthesia (spinal, epidural, or both techniques combined with no sedation; n = 476) or general anesthesia (intravenous, inhalational, or combined anesthetic agents; n = 474). Main Outcomes and Measures: Primary outcome was incidence of delirium during the first 7 postoperative days. Secondary outcomes analyzed in this article include delirium severity, duration, and subtype; postoperative pain score; length of hospitalization; 30-day all-cause mortality; and complications. Results: Among 950 randomized patients (mean age, 76.5 years; 247 [26.8%] male), 941 were evaluable for the primary outcome (6 canceled surgery and 3 withdrew consent). Postoperative delirium occurred in 29 (6.2%) in the regional anesthesia group vs 24 (5.1%) in the general anesthesia group (unadjusted risk difference [RD], 1.1%; 95% CI, -1.7% to 3.8%; P = .48; unadjusted relative risk [RR], 1.2 [95% CI, 0.7 to 2.0]; P = .57]). Mean severity score of delirium was 23.0 vs 24.1, respectively (unadjusted difference, -1.1; 95% CI, -4.6 to 3.1). A single delirium episode occurred in 16 (3.4%) vs 10 (2.1%) (unadjusted RD, 1.1%; 95% CI, -1.7% to 3.9%; RR, 1.6 [95% CI, 0.7 to 3.5]). Hypoactive subtype in 11 (37.9%) vs 5 (20.8%) (RD, 11.5; 95% CI, -11.0% to 35.7%; RR, 2.2 [95% CI, 0.8 to 6.3]). Median worst pain score was 0 (IQR, 0 to 20) vs 0 (IQR, 0 to 10) (difference 0; 95% CI, 0 to 0). Median length of hospitalization was 7 days (IQR, 5 to 10) vs 7 days (IQR, 6 to 10) (difference 0; 95% CI, 0 to 0). Death occurred in 8 (1.7%) vs 4 (0.9%) (unadjusted RD, -0.8%; 95% CI, -2.2% to 0.7%; RR, 2.0 [95% CI, 0.6 to 6.5]). Adverse events were reported in 106 episodes in the regional anesthesia group and 102 in the general anesthesia group; the most frequently reported adverse events were nausea and vomiting (47 [44.3%] vs 34 [33.3%]) and postoperative hypotension (13 [12.3%] vs 10 [9.8%]). Conclusions and Relevance: In patients aged 65 years and older undergoing hip fracture surgery, regional anesthesia without sedation did not significantly reduce the incidence of postoperative delirium compared with general anesthesia. Trial Registration: ClinicalTrials.gov Identifier: NCT02213380.

Resolvin Conjugates in Tissue Regeneration 1 Promote Alveolar Fluid Clearance by Activating Alveolar Epithelial Sodium Channels and Na, K-ATPase in Lipopolysaccharide-Induced Acute Lung Injury.

Acute respiratory distress syndrome (ARDS), a common and fatal clinical condition, is characterized by the destruction of epithelium and augmented permeability of the alveolar-capillary barrier. Resolvin conjugates in tissue regeneration 1 (RCTR1) is an endogenous lipid mediator derived from docosahexaenoic acid , exerting proresolution effects in the process of inflammation. In our research, we evaluated the role of RCTR1 in alveolar fluid clearance (AFC) in lipopolysaccharide-induced ARDS/acute lung injury (ALI) rat model. Rats were injected with RCTR1 (5 µg/kg) via caudal veins 8 hours after lipopolysaccharide (LPS) (14 mg/kg) treatment, and then AFC was estimated after 1 hour of ventilation. Primary type II alveolar epithelial cells were incubated with LPS (1 ug/ml) with or without RCTR1 (10 nM) for 8 hours. Our results showed that RCTR1 significantly enhanced the survival rate, promoted the AFC, and alleviated LPS-induced ARDS/ALI in vivo. Furthermore, RCTR1 remarkably elevated the protein expression of sodium channels and Na, K-ATPase and the activity of Na, K-ATPase in vivo and in vitro. Additionally, RCTR1 also decreased neural precursor cell expressed developmentally downregulated 4-2 (Nedd4-2) level via upregulating Ser473-phosphorylated-Akt expression. Besides this, inhibitors of receptor for lipoxin A4 (ALX), cAMP, and phosphatidylinositol 3-kinase (PI3K) (BOC-2, KH-7, and LY294002) notably inhibited the effects of RCTR1 on AFC. In summary, RCTR1 enhances the protein levels of sodium channels and Na, K-ATPase and the Na, K-ATPase activity to improve AFC in ALI through ALX/cAMP/PI3K/Nedd4-2 pathway, suggesting that RCTR1 may become a therapeutic drug for ARDS/ALI. SIGNIFICANCE STATEMENT: RCTR1, an endogenous lipid mediator, enhanced the rate of AFC to accelerate the resolution of inflammation in the LPS-induced murine lung injury model. RCTR1 upregulates the expression of epithelial sodium channels (ENaCs) and Na, K-ATPase in vivo and in vitro to accelerate the AFC. The efficacy of RCTR1 on the ENaC and Na, K-ATPase level was in an ALX/cAMP/PI3K/Nedd4-2-dependent manner.

MCTR1 enhances the resolution of lipopolysaccharide-induced lung injury through STAT6-mediated resident M2 alveolar macrophage polarization in mice.

Acute respiratory distress syndrome (ARDS) is a fatal disease characterized by excessive infiltration of inflammatory cells. MCTR1 is an endogenously pro-resolution lipid mediator. We tested the hypothesis that MCTR1 accelerates inflammation resolution through resident M2 alveolar macrophage polarization. The mice received MCTR1 via intraperitoneal administration 3 days after LPS stimulation, and then, the bronchoalveolar lavage (BAL) fluid was collected 24 hours later to measure the neutrophil numbers. Flow cytometry was used to sort the resident and recruited macrophages. Post-treatment with MCTR1 offered dramatic benefits in the resolution phase of LPS-induced lung injury, including decreased neutrophil numbers, reduced BAL fluid protein and albumin concentrations and reduced histological injury. In addition, the expression of the M2 markers Arg1, FIZZ1, Remlα, CD206 and Dectin-1 was increased on resident macrophages in the LPS + MCTR1 group. Resident macrophage depletion abrogated the therapeutic effects of MCTR1, and reinjection of the sorted resident macrophages into the lung decreased neutrophil numbers. Finally, treatment with MCTR1 increased STAT6 phosphorylation. The STAT6 inhibitor AS1517499 abolished the beneficial effects of MCTR1. In conclusion, MCTR1 promotes resident M2 alveolar macrophage polarization via the STAT6 pathway to accelerate resolution of LPS-induced lung injury.

PDX regulates inflammatory cell infiltration via resident macrophage in LPS-induced lung injury.

Inflammatory cell infiltration contributes to the pathogenesis of acute respiratory distress syndrome (ARDS). Protectin DX (PDX), an endogenous lipid mediator, shows anti-inflammatory and proresolution bioactions. In vivo, the mice were intraperitoneally injected with PDX (0.1 µg/mouse) after intratracheal (1 mg/kg) or intraperitoneal (10 mg/kg) LPS administration. Flow cytometry was used to measure inflammatory cell numbers. Clodronate liposomes were used to deplete resident macrophages. RT-PCR, and ELISA was used to measure MIP-2, MCP-1, TNF-α and MMP9 levels. In vitro, sorted neutrophils, resident and recruited macrophages (1 × 106 ) were cultured with 1 µg/mL LPS and/or 100 nmol/L PDX to assess the chemokine receptor expression. PDX attenuated LPS-induced lung injury via inhibiting recruited macrophage and neutrophil recruitment through repressing resident macrophage MCP-1, MIP-2 expression and release, respectively. Finally, PDX inhibition of neutrophil infiltration and transmembrane was associated with TNF-α/MIP-2/MMP9 signalling pathway. These data suggest that PDX attenuates LPS-stimulated lung injury via reduction of the inflammatory cell recruitment mediated via resident macrophages.

Maresin Conjugates in Tissue Regeneration 1 improves alveolar fluid clearance by up-regulating alveolar ENaC, Na, K-ATPase in lipopolysaccharide-induced acute lung injury.

Maresin Conjugates in Tissue Regeneration 1 (MCTR1) is a newly identified macrophage-derived sulfido-conjugated mediator that stimulates the resolution of inflammation. This study assessed the role of MCTR1 in alveolar fluid clearance (AFC) in a rat model of acute lung injury (ALI) induced by lipopolysaccharide (LPS). Rats were intravenously injected with MCTR1 at a dose of 200 ng/rat, 8 hours after administration of 14 mg/kg LPS. The level of AFC was then determined in live rats. Primary rat ATII (Alveolar Type II) epithelial cells were also treated with MCTR1 (100 nmol/L) in a culture medium containing LPS for 8 hours. MCTR1 treatment improved AFC (18.85 ± 2.07 vs 10.11 ± 1.08, P < .0001) and ameliorated ALI in rats. MCTR1 also significantly promoted AFC by up-regulating epithelial sodium channel (ENaC) and Na+ -K+ -adenosine triphosphatase (Na, K-ATPase) expressions in vivo. MCTR1 also activated Na, K-ATPase and elevated phosphorylated-Akt (P-Akt) by up-regulating the expression of phosphorylated Nedd4-2 (P-Nedd4-2) in vivo and in vitro. However, BOC-2 (ALX inhibitor), KH7 (cAMP inhibitor) and LY294002 (PI3K inhibitor) abrogated the improved AFC induced by MCTR1. Based on the findings of this study, MCTR1 may be a novel therapeutic approach to improve reabsorption of pulmonary oedema during ALI/acute respiratory distress syndrome (ARDS).

PCTR1 improves pulmonary edema fluid clearance through activating the sodium channel and lymphatic drainage in lipopolysaccharide-induced ARDS.

Acute respiratory distress syndrome (ARDS) is a lethal clinical syndrome characterized by damage of the epithelial barriers and accumulation of pulmonary edema fluid. Protectin conjugates in tissue regeneration 1 (PCTR1), an endogenously produced lipid mediator, are believed to exert anti-inflammatory and pro-resolution effects. PCTR1 (1 µg/kg) was injected at 8 hr after lipopolysaccharide (LPS; 14 mg/kg) administration, and the rate of pulmonary fluid clearance was measured in live rats at 1 hr after PCTR1 treatment. The primary type II alveolar epithelial cells were cultured with PCTR1 (10 nmol/ml) and LPS (1 µg/ml) for 8 hr. PCTR1 effectively improved pulmonary fluid clearance and ameliorated morphological damage and reduced inflammation of lung tissue, as well as improved the survival rate in the LPS-induced acute lung injury (ALI) model. Moreover, PCTR1 markedly increased sodium channel expression as well as Na, K-ATPase expression and activity in vivo and in vitro. In addition, PCTR1i also upregulated the expression of LYVE-1 in vivo. Besides that, BOC-2, HK7, and LY294002 blocked the promoted effect of PCTR1 on pulmonary fluid clearance. Taken together, PCTR1 upregulates sodium channels' expression via activating the ALX/cAMP/P-Akt/Nedd4-2 pathway and increases Na, K-ATPase expression and activity to promote alveolar fluid clearance. Moreover, PCTR1 also promotes the expression of LYVE-1 to recover the lymphatic drainage resulting in the increase of lung interstitial fluid clearance. In summary, these results highlight a novel systematic mechanism for PCTR1 in pulmonary edema fluid clearance after ALI/ARDS, suggesting its potential role in a therapeutic approach for ALI/ARDS.

MCTR1 alleviates lipopolysaccharide-induced acute lung injury by protecting lung endothelial glycocalyx.

Endothelial glycocalyx degradation, critical for increased pulmonary vascular permeability, is thought to facilitate the development of sepsis into the multiple organ failure. Maresin conjugates in tissue regeneration 1 (MCTR1), a macrophage-derived lipid mediator, which exhibits potentially beneficial effects via the regulation of bacterial phagocytosis, promotion of inflammation resolution, and regeneration of tissue. In this study, we show that MCTR1 (100 ng/mouse) enhances the survival of mice with lipopolysaccharide (LPS)-induced (15 mg/kg) sepsis. MCTR1 alleviates LPS (10 mg/kg)-induced lung dysfunction and lung tissue inflammatory response by decreasing inflammatory cytokines (tumor necrosis factor-α, interleukin-1ß [IL-1ß], and IL-6) expression in serum and reducing the serum levels of heparan sulfate (HS) and syndecan-1. In human umbilical vein endothelial cells (HUVECs) experiments, MCTR1 (100 nM) was added to the culture medium with LPS for 6 hr. MCTR1 treatment markedly inhibited HS degradation by downregulating heparanase (HPA) protein expression in vivo and in vitro. Further analyses indicated that MCTR1 upregulates sirtuin 1 (SIRT1) expression and decreases NF-κB p65 phosphorylation. In the presence of BOC-2 or EX527, the above effects of MCTR1 were abolished. These results suggest that MCTR1 protects against LPS-induced sepsis in mice by attenuating pulmonary endothelial glycocalyx injury via the ALX/SIRT1/NF-κB/HPA pathway.

Analgesia of Patients with Multiple Rib Fractures in Critical Care: A Survey of Healthcare Professionals in the UK.

INTRODUCTION: Good analgesia has been shown to reduce the risk of pneumonia, chronic pain, and mortality in patients with multiple rib fractures (MRFs). This survey explores the current analgesic practice in the UK, protocol use, barriers to provision, and physician preferences. MATERIALS AND METHODS: A web-based survey was distributed nationally to an enriched cohort of clinicians working in UK trauma units with an interest in MRF management. RESULTS: Seventy-nine healthcare professionals responded. A third (31.4%) reported that their department had a rib fracture pain protocol, 52.9% did not, and 15.7% were unsure. Significantly more respondents reported adequate pain control when a hospital protocol was present compared to when not (χ 2, p < 0.01). Inadequate analgesia, a poor cough, and inability to breathe deeply were the commonest complications reported by 81.4, 78.6, and 65.7%, respectively. Patient-controlled analgesia (PCA) was the most commonly used form of analgesia (38.6%) followed by thoracic epidural (TEA) (30.0%) and continuous opioid infusion (18.6%). However, TEA was the preferred method of analgesia among respondents (37.1%) followed by serratus block (21.4%), paravertebral block (17.1%), and PCA (14.3%). DISCUSSION: There is considerable variation among physicians in their current use of analgesic modalities, with opiate-based methods predominating despite a physician preference for regional techniques. Thoracic epidurals are preferred by physicians but of limited use as a result of contraindications, time pressures, and staff skill mix. Pain control is reported to be better handled when protocols are present. Further research focusing on currently utilized regional techniques is required in order to produce a validated standardized national protocol that is informed by the current practice, the evidence base, and limitations to service provision. KEY MESSAGES: There is considerable variation among physicians in their current use of analgesic modalities. Opiate-based methods dominate for thoracic trauma despite a physician preference for regional techniques, which can be challenging in this cohort due to contraindications, staff skill mix, and time pressures. Inadequate analgesia is common but is better managed when pain management protocols are available. HOW TO CITE THIS ARTICLE: Beard L, Holt B, Snelson C, Parcha C, Smith FG, Veenith T. Analgesia of Patients with Multiple Rib Fractures in Critical Care: A Survey of Healthcare Professionals in the UK. Indian J Crit Care Med 2020;24(3):184-189.

Resolvin D1 Improves the Resolution of Inflammation via Activating NF-κB p50/p50-Mediated Cyclooxygenase-2 Expression in Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) is a severe illness characterized by uncontrolled inflammation. The resolution of inflammation is a tightly regulated event controlled by endogenous mediators, such as resolvin D1 (RvD1). Cyclooxygenase-2 (COX-2) has been reported to promote inflammation, along with PGE2, in the initiation of inflammation, as well as in prompting resolution, with PGD2 acting in the later phase of inflammation. Our previous work demonstrated that RvD1 enhanced COX-2 and PGD2 expression to resolve inflammation. In this study, we investigated mechanisms underlying the effect of RvD1 in modulating proresolving COX-2 expression. In a self-limited ARDS model, an LPS challenge induced the biphasic activation of COX-2, and RvD1 promoted COX-2 expression during the resolution phase. However, it was significantly blocked by treatment of a NF-κB inhibitor. In pulmonary fibroblasts, NF-κB p50/p50 was shown to be responsible for the proresolving activity of COX-2. Additionally, RvD1 potently promoted p50 homodimer nuclear translocation and robustly triggered DNA-binding activity, upregulating COX-2 expression via lipoxin A4 receptor/formyl peptide receptor 2. Finally, the absence of p50 in knockout mice prevented RvD1 from promoting COX-2 and PGD2 expression and resulted in excessive pulmonary inflammation. In conclusion, RvD1 expedites the resolution of inflammation through activation of lipoxin A4 receptor/formyl peptide receptor 2 receptor and NF-κB p50/p50-COX-2 signaling pathways, indicating that RvD1 might have therapeutic potential in the management of ARDS.

Maresin1 Alleviates Metabolic Dysfunction in Septic Mice: A 1H NMR-Based Metabolomics Analysis.

Maresin1 (MaR1), a new anti-inflammatory and proresolving lipid mediator, has been proven to exert organ-protective effects in septic animal models. However, the potential mechanisms are still not fully elucidated. In this study, we sought to explore the impact of MaR1 on metabolic dysfunction in cecal ligation and puncture- (CLP-) induced septic mice. We found that MaR1 significantly increased the overall survival rate and attenuated lung and liver injuries in septic mice. In addition, MaR1 markedly reduced the levels of proinflammatory cytokines (TNF-α and IL-6) and alleviated mitochondrial damage. Based on a 1H NMR-based metabolomics analysis, CLP-induced septic mice had increased levels of acetate, pyruvate, and lactate in serum and decreased levels of alanine, aspartate, glutamate, and fumarate in lungs. However, these metabolic disorders, mainly involving energy and amino acid metabolism, can be recovered by MaR1 treatment. Therefore, our results suggest that the protective effects of MaR1 on sepsis could be related to the recovery of metabolic dysfunction and the alleviation of inflammation and mitochondrial damage.

Maresin 1 attenuates mitochondrial dysfunction through the ALX/cAMP/ROS pathway in the cecal ligation and puncture mouse model and sepsis patients.

Inflammation always accompanies infection during sepsis. Mitochondrial dysfunction and the role of reactive oxygen species (ROS) produced by mitochondria have been proposed in the pathogenesis of sepsis. Maresins have protective and resolving effects in experimental models of infection. In the present study, we investigated the effects of maresin 1 (MaR1) on mitochondrial function in cecal ligation and puncture (CLP)-induced sepsis and sepsis patients to identify mechanisms underlying maresin 1-mediated stimulation of ROS in mitochondria. We found that treatment with MaR1 significantly inhibited production of cytokines, decreased bacterial load in the peritoneal lavage fluid, reduced the number of neutrophils, decreased lactic acid level and upregulated cyclic AMP (cAMP) concentration, with the outcome of decreased lung injury in CLP-induced sepsis in mice. The effects of MaR1 on downregulation nitric oxide (NOX) activity, improvement CAT and SOD activity to inhibit ROS production in mitochondria was dependent on lipoxin receptor (ALX) and cAMP. Survival rates were significantly increased after the treatment of mice with MaR1. In BMDM stimulated with LPS, MaR1 inhibited the ROS production, downregulated enzyme activity, reduced mtO2 production, increased mitochondrial membrane potential, improved adenosine triphosphate (ATP) content and mitochondrial DNA (mtDNA) copy number. Finally, the effects of MaR1 on ROS production in the blood of healthy volunteers stimulated with LPS or sepsis patients were associated with ALX and cAMP. Taken together, these data suggest that treatment with MaR1 could attenuate mitochondrial dysfunction during sepsis through regulating ROS production.

Maresin1 stimulates alveolar fluid clearance through the alveolar epithelial sodium channel Na,K-ATPase via the ALX/PI3K/Nedd4-2 pathway.

Maresin1 (MaR1) is a new docosahexaenoic acid-derived pro-resolving agent that promotes the resolution of inflammation. In this study, we sought to investigate the effect and underlining mechanisms of MaR1 in modulating alveolar fluid clearance (AFC) on LPS-induced acute lung injury. MaR1 was injected intravenously or administered by instillation (200 ng/kg) 8 h after LPS (14 mg/kg) administration and AFC was measured in live rats. In primary rat alveolar type II epithelial cells, MaR1 (100 nM) was added to the culture medium with lipopolysaccharide for 6 h. MaR1 markedly stimulated AFC in LPS-induced lung injury, with the outcome of decreased pulmonary edema and lung injury. In addition, rat lung tissue protein was isolated after intervention, and we found MaR1 improved epithelial sodium channel (ENaC), Na,K-adenosine triphosphatase (ATPase) protein expression and Na,K-ATPase activity. MaR1 down-regulated Nedd4-2 protein expression though PI3k/Akt but not though PI3k/SGK1 pathway in vivo. In primary rat alveolar type II epithelial cells stimulated with LPS, MaR1-upregulated ENaC and Na,K-ATPase protein abundance in the plasma membrane. Finally, the lipoxin A4 Receptor inhibitor (BOC-2) and PI3K inhibitor (LY294002) not only blocked MaR1's effects on cAMP/cGMP, the expression of phosphorylated Akt and Nedd4-2, but also inhibited the effect of MaR1 on AFC in vivo. In conclusion, MaR1 stimulates AFC through a mechanism partly dependent on alveolar epithelial ENaC and Na,K-ATPase activation via the ALX/PI3K/Nedd4-2 signaling pathway. Our findings reveal a novel mechanism for pulmonary edema fluid reabsorption and MaR1 may provide a new therapy for the resolution of ALI/ARDS.

Cell salvage and donor blood transfusion during cesarean section: A pragmatic, multicentre randomised controlled trial (SALVO).

BACKGROUND: Excessive haemorrhage at cesarean section requires donor (allogeneic) blood transfusion. Cell salvage may reduce this requirement. METHODS AND FINDINGS: We conducted a pragmatic randomised controlled trial (at 26 obstetric units; participants recruited from 4 June 2013 to 17 April 2016) of routine cell salvage use (intervention) versus current standard of care without routine salvage use (control) in cesarean section among women at risk of haemorrhage. Randomisation was stratified, using random permuted blocks of variable sizes. In an intention-to-treat analysis, we used multivariable models, adjusting for stratification variables and prognostic factors identified a priori, to compare rates of donor blood transfusion (primary outcome) and fetomaternal haemorrhage ≥2 ml in RhD-negative women with RhD-positive babies (a secondary outcome) between groups. Among 3,028 women randomised (2,990 analysed), 95.6% of 1,498 assigned to intervention had cell salvage deployed (50.8% had salvaged blood returned; mean 259.9 ml) versus 3.9% of 1,492 assigned to control. Donor blood transfusion rate was 3.5% in the control group versus 2.5% in the intervention group (adjusted odds ratio [OR] 0.65, 95% confidence interval [CI] 0.42 to 1.01, p = 0.056; adjusted risk difference -1.03, 95% CI -2.13 to 0.06). In a planned subgroup analysis, the transfusion rate was 4.6% in women assigned to control versus 3.0% in the intervention group among emergency cesareans (adjusted OR 0.58, 95% CI 0.34 to 0.99), whereas it was 2.2% versus 1.8% among elective cesareans (adjusted OR 0.83, 95% CI 0.38 to 1.83) (interaction p = 0.46). No case of amniotic fluid embolism was observed. The rate of fetomaternal haemorrhage was higher with the intervention (10.5% in the control group versus 25.6% in the intervention group, adjusted OR 5.63, 95% CI 1.43 to 22.14, p = 0.013). We are unable to comment on long-term antibody sensitisation effects. CONCLUSIONS: The overall reduction observed in donor blood transfusion associated with the routine use of cell salvage during cesarean section was not statistically significant. TRIAL REGISTRATION: This trial was prospectively registered on ISRCTN as trial number 66118656 and can be viewed on http://www.isrctn.com/ISRCTN66118656.

Characterization of systemic neutrophil function in patients undergoing colorectal cancer resection.

BACKGROUND: In patients with colorectal cancer, the generation and maintenance of a systemic inflammatory response is associated with poor outcomes. Neutrophils have been implicated in the prognosis of such patients, but little is known about their functional response to surgery. This study was conducted to characterize neutrophil function of patients undergoing colorectal cancer resection. MATERIALS AND METHODS: Systemic neutrophils were isolated from patients with colorectal cancer who underwent surgical resection preoperatively (day 0) and postoperatively (day 1 and day 3). Neutrophils were stimulated to produce neutrophil extracellular traps, which were quantified by a measure of the fluorescence of the extracellular DNA. Neutrophil apoptosis and phagocytosis were measured by fluorescence-activated cell sorting. RESULTS: Forty-five patients were evaluated. Statistically significant differences were identified in NET formation over the perioperative period (reduced NET production [day 0 to day 1] and restored NET production [day 1 to day 3]) in the absence of stimulation (P = 0.0016) and in response to stimulation with interleukin 8 (P = 0.0045), lipopolysaccharide (P = 0.0025), and N-formylmethionyl-leucyl-phenylalanine (P = 0.0014). No statistically significant differences were identified in apoptosis at 4-hour incubation; however, at 24-hours, significant differences were identified in alive (P < 0.0001), early apoptotic (P = 0.0008) and late apoptotic (P = 0.0018) stages (impaired apoptosis [day 0 to day 1] and restored apoptosis [day 1 to day 3]). Demonstrable, but nonsignificant, increases in neutrophil phagocytotic activity were revealed on sequential perioperative days, and a significant increase in phagocytosis was identified from day 1 to day 3 in response to E coli (P = 0.0078). CONCLUSIONS: A novel neutrophil phenotype demonstrating reduced NET formation, reduced apoptosis, and increased phagocytosis has been demonstrated in patients undergoing colorectal cancer resection. As a consequence of impaired cell death, an accumulation of neutrophils in the circulation could be potentially harmful to the host following surgery and an early phenotypic switch may be desirable.

Resolvin D1 stimulates alveolar fluid clearance through alveolar epithelial sodium channel, Na,K-ATPase via ALX/cAMP/PI3K pathway in lipopolysaccharide-induced acute lung injury.

Resolvin D1 (7S,8R,17S-trihydroxy-4Z,9E,11E,13Z,15E,19Z-docosahexaenoic acid) (RvD1), generated from ω-3 fatty docosahexaenoic acids, is believed to exert anti-inflammatory properties including inhibition of neutrophil activation and regulating inflammatory cytokines. In this study, we sought to investigate the effect of RvD1 in modulating alveolar fluid clearance (AFC) on LPS-induced acute lung injury. In vivo, RvD1 was injected i.v. (5 µg/kg) 8 h after LPS (20 mg/kg) administration, which markedly stimulated AFC in LPS-induced lung injury, with the outcome of decreased pulmonary edema. In addition, rat lung tissue protein was isolated after intervention and we found RvD1 improved epithelial sodium channel (ENaC) α, γ, Na,K-adenosine triphosphatase (ATPase) α1, ß1 subunit protein expression and Na,K-ATPase activity. In primary rat alveolar type II epithelial cells stimulated with LPS, RvD1 not only upregulated ENaC α, γ and Na,K-ATPase α1 subunits protein expression, but also increased Na+ currents and Na,K-ATPase activity. Finally, protein kinase A and cGMP were not responsible for RvD1's function because a protein kinase A inhibitor (H89) and cGMP inhibitor (Rp-cGMP) did not reduce RvD1's effects. However, the RvD1 receptor (formyl-peptide receptor type 2 [FPR2], also called ALX [the lipoxin A4 receptor]) inhibitor (BOC-2), cAMP inhibitor (Rp-cAMP), and PI3K inhibitor (LY294002) not only blocked RvD1's effects on the expression of ENaC α in vitro, but also inhibited the AFC in vivo. In summary, RvD1 stimulates AFC through a mechanism partly dependent on alveolar epithelial ENaC and Na,K-ATPase activation via the ALX/cAMP/PI3K signaling pathway.

Paravertebral block versus thoracic epidural for patients undergoing thoracotomy.

BACKGROUND: Operations on structures in the chest (usually the lungs) involve cutting between the ribs (thoracotomy). Severe post-thoracotomy pain can result from pleural (lung lining) and muscular damage, costovertebral joint (ribcage) disruption and intercostal nerve (nerves that run along the ribs) damage during surgery. Poor pain relief after surgery can impede recovery and increase the risks of developing complications such as lung collapse, chest infections and blood clots due to ineffective breathing and clearing of secretions. Effective management of acute pain following thoracotomy may prevent these complications and reduce the likelihood of developing chronic pain. A multi-modal approach to analgesia is widely employed by thoracic anaesthetists using a combination of regional anaesthetic blockade and systemic analgesia, with both non-opioid and opioid medications and local anaesthesia blockade.There is some evidence that blocking the nerves as they emerge from the spinal column (paravertebral block, PVB) may be associated with a lower risk of major complications in thoracic surgery but the majority of thoracic anaesthetists still prefer to use a thoracic epidural blockade (TEB) as analgesia for their patients undergoing thoracotomy. In order to bring about a change in practice, anaesthetists need a review that evaluates the risk of all major complications associated with thoracic epidural and paravertebral block in thoracotomy. OBJECTIVES: To compare the two regional techniques of TEB and PVB in adults undergoing elective thoracotomy with respect to:1. analgesic efficacy;2. the incidence of major complications (including mortality);3. the incidence of minor complications;4. length of hospital stay;5. cost effectiveness. SEARCH METHODS: We searched for studies in the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 9); MEDLINE via Ovid (1966 to 16 October 2013); EMBASE via Ovid (1980 to 16 October 2013); CINAHL via EBSCO host (1982 to 16 October 2013); and reference lists of retrieved studies. We handsearched the Journal of Cardiothoracic Surgery and Journal of Cardiothoracic and Vascular Anesthesia (16 October 2013). We reran the search on 31st January 2015. We found one additional study which is awaiting classification and will be addressed when we update the review. SELECTION CRITERIA: We included all randomized controlled trials (RCTs) comparing PVB with TEB in thoracotomy, including upper gastrointestinal surgery. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Two review authors (JY and SG) independently assessed the studies for inclusion and then extracted data as eligible for inclusion in qualitative and quantitative synthesis (meta-analysis). MAIN RESULTS: We included 14 studies with a total of 698 participants undergoing thoracotomy. There are two studies awaiting classification. The studies demonstrated high heterogeneity in insertion and use of both regional techniques, reflecting real-world differences in the anaesthesia techniques. Overall, the included studies have a moderate to high potential for bias, lacking details of randomization, group allocation concealment or arrangements to blind participants or outcome assessors. There was low to very low-quality evidence that showed no significant difference in 30-day mortality (2 studies, 125 participants. risk ratio (RR) 1.28, 95% confidence interval (CI) 0.39 to 4.23, P value = 0.68) and major complications (cardiovascular: 2 studies, 114 participants. Hypotension RR 0.30, 95% CI 0.01 to 6.62, P value = 0.45; arrhythmias RR 0.36, 95% CI 0.04 to 3.29, P value = 0.36, myocardial infarction RR 3.19, 95% CI 0.13, 76.42, P value = 0.47); respiratory: 5 studies, 280 participants. RR 0.62, 95% CI 0.26 to 1.52, P value = 0.30). There was moderate-quality evidence that showed comparable analgesic efficacy across all time points both at rest and after coughing or physiotherapy (14 studies, 698 participants). There was moderate-quality evidence that showed PVB had a better minor complication profile than TEB including hypotension (8 studies, 445 participants. RR 0.16, 95% CI 0.07 to 0.38, P value < 0.0001), nausea and vomiting (6 studies, 345 participants. RR 0.48, 95% CI 0.30 to 0.75, P value = 0.001), pruritis (5 studies, 249 participants. RR 0.29, 95% CI 0.14 to 0.59, P value = 0.0005) and urinary retention (5 studies, 258 participants. RR 0.22, 95% CI 0.11 to 0.46, P value < 0.0001). There was insufficient data in chronic pain (six or 12 months). There was no difference found in and length of hospital stay (3 studies, 124 participants). We found no studies that reported costs. AUTHORS' CONCLUSIONS: Paravertebral blockade reduced the risks of developing minor complications compared to thoracic epidural blockade. Paravertebral blockade was as effective as thoracic epidural blockade in controlling acute pain. There was a lack of evidence in other outcomes. There was no difference in 30-day mortality, major complications, or length of hospital stay. There was insufficient data on chronic pain and costs. Results from this review should be interpreted with caution due to the heterogeneity of the included studies and the lack of reliable evidence. Future studies in this area need well-conducted, adequately-powered RCTs that focus not only on acute pain but also on major complications, chronic pain, length of stay and costs.

Lipoxin A4 activates alveolar epithelial sodium channel gamma via the microRNA-21/PTEN/AKT pathway in lipopolysaccharide-induced inflammatory lung injury.

Lipoxin A4 (LXA4), as an endogenously produced lipid mediator, promotes the resolution of inflammation. Previously, we demonstrated that LXA4 stimulated alveolar fluid clearance through alveolar epithelial sodium channel gamma (ENaC-γ). In this study, we sought to investigate the mechanisms of LXA4 in modulation of ENaC-γ in lipopolysaccharide (LPS)-induced inflammatory lung injury. miR-21 was upregulated during an LPS challenge and downregulated by LXA4 administration in vivo and in vitro. Serum miR-21 concentration was also elevated in acute respiratory distress syndrome patients as compared with healthy volunteers. LPS increased miR-21 expression by activation of activator protein 1 (AP-1). In A549 cells, miR-21 upregulated phosphorylation of AKT activation via inhibition of phosphatase and tensin homolog (PTEN), and therefore reduced the expression of ENaC-γ. In contrast, LXA4 reversed LPS-inhibited ENaC-γ expression through inhibition of AP-1 and activation of PTEN. In addition, an miR-21 inhibitor mimicked the effects of LXA4; overexpression of miR-21 abolished the protective effects of LXA4. Finally, both AKT and ERK inhibitors (LY294002 and UO126) blocked effects of LPS on the depression of ENaC-γ. However, LXA4 only inhibited LPS-induced phosphorylation of AKT. In summary, LXA4 activates ENaC-γ in part via the miR-21/PTEN/AKT signaling pathway.