Association Between Perfusate Oxygenation and Acute Lung Injury in Tetralogy of Fallot Surgery Purpose: Little is known regarding precise estimates of the association between perfusate oxygenation (PpO2) and acute lung injury (ALI) following tetralogy of Fallot repair. The objective is to investigate PpO2 and the risk of ALI following tetralogy of Fallot repair in pediatric patients. Methods: We conducted a nested case-control study within a prospective Chinese TedaICH cohort including 134 ALI patients aged 1 month to 18 years undergoing complete repair of tetralogy of Fallot, and each was matched to 2 controls. We selected the highest PpO2 during aortic crossclamp as the exposure. Conditional logistic regression was used to quantify the association between PpO2 and overall ALI risk by covariates of interest. We identified and integrated the risk covariates to build ALI nomograms and internally validated the nomograms using bootstrapping. Results: After adjusting for covariates, continuously and categorically higher PpO2 values were associated with ALI risk (all p < 0.05), especially for those with a z-score of pulmonary annulus < -4.0 (p = 0.002), McGoon ratio < 1.5 (p = 0.029), and major aortopulmonary collateral arteries (p = 0.005), despite no statistical heterogeneity (all p interaction >0.05). Younger age, lower oxyhemoglobin saturation, untreated minor aortopulmonary collateral arteries, transannular patch, larger transpulmonary gradient, major transfusion, and longer cardiopulmonary bypass time were independent risk factors for ALI (all p < 0.05). Combining the PpO2 nomogram provided further risk discriminative information on ALI diagnosis compared with the covariate-based nomogram alone in the training cohort (AUC 0.865, 95% CI [0.828 to 0.903] vs 0.869 [0.832 to 0.906], respectively) with no statistical significance (p = 0.445). Conclusions: The findings suggested an association between high PpO2 and ALI risk, and more importance should be attached to independent risk factors for ALI. Address reprint requests to Zhi-gang Liu, MD, PhD, Department of Cardiovascular Surgery, Graduate School, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, P.R China. E-mail: liuzgtich@sina.com, Yong-feng Shao, MD, PhD, Department of Cardiovascular Surgery, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210038, P.R China. E-mail: yfshaojph@sina.com, Hong Liu, MD, PhD, Department of Cardiovascular Surgery, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210038, P.R China. E-mail: dr.hongliu@foxmail.com Received 26 August, 2019 Revised 23 September, 2019 Accepted 25 October, 2019 Funding/Support: The research was supported by Fundamental Research Funds for the Central Universities (No.3332018189) and National Clinical Key Specialty Construction Projects of China. Conflict of interest: The authors have no conflict of interests. ClinicalTrials.gov: NCT03568357. © 2019 by the Shock Society

Resuscitation Fluids in Septic Shock: A Network Meta-Analysis of Randomized Controlled Trials The aim of this study was to assess the efficacy and safety of various resuscitation fluids in septic shock by adopting a network meta-analysis (NMA). Randomized controlled trials (RCTs) comparing resuscitation fluids in septic shock were carried out by retrieving electronic databases. NMAs of 28-day mortality, 90-day mortality, incidence of acute kidney injury (AKI), and the need for renal replacement therapy (RRT) were conducted using the STATA 15.0 software. Probability-based ranking and surface under cumulative ranking (SUCRA) were performed to identify the optimal resuscitation fluid. Inconsistencies were evaluated by node-splitting analysis and a loop-specific approach. Furthermore, publication bias was analyzed by funnel plots. A total of 13 RCTs were enrolled in the analysis. The NMA results revealed that no significant differences were detected in the outcomes of 28-day mortality and 90-day mortality among various resuscitation fluids. The SUCRAs (the first indicates the best) of 28-day mortality showed that the hypertonic sodium chloride/hydroxyethyl starch 40 solution ranked the highest (93.8%), followed by the balanced solution (BS) (69.6%), and albumin (61.9%). On the other hand, the SUCRAs of 90-day mortality revealed that gelatin (GEL) ranked the highest (75.1%), followed by BS (55.1%), and NS (52.4%). The NMA results of AKI demonstrated that high-molecular-weight hydroxyethyl starch (H-HES) was associated with increased risk of AKI in comparison with GEL, BS, and L-HES. The SUCRAs of AKI showed that GEL ranked the highest (74.4%), followed by NS (64.9%), and BS (58.3%). In addition, the NMA results of RRT revealed that H-HES was associated with an increased need for RRT in comparison with BS and NS, and L-HES was associated with increased need of RRT in comparison with BS. The SUCRAs of RRT revealed that NS ranked the highest (91.6%), followed by BS (74.4%) and L-HES (36.1%). No significant inconsistencies were shown by the node-splitting analysis and no publication bias was demonstrated in the funnel plots. In conclusion, BS was determined as the preferred resuscitation fluid for septic shock. Moreover, the use of GEL requires further evaluation. H-HES was associated with a significant risk of AKI and RRT, whereas L-HES with an increased need for RRT compared with BS. Thus, both resuscitation fluids should be avoided for septic shock. Address reprint requests to Liangming Liu, State Key Laboratory of Trauma, Burns, and Combined Injury, Department 2, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing 400042, P.R. China. E-mail: liangmingliu@yahoo.com. Co-correspondence: Tao Li, PhD, MD, State Key Laboratory of Trauma, Burns, and Combined Injury, Department 2, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing 400042, P.R. China. E-mail: lt200132@163.com. Received 11 August, 2019 Revised 16 September, 2019 Accepted 16 October, 2019 This work was supported by the Military Key Projects (Grant No. AWS16J032). The authors report no conflicts of interest. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). © 2019 by the Shock Society

Shock, not Blood Pressure or Shock, Determines the need for Thoracic Damage Control Following Penetrating Trauma Background: Damage control laparotomy has increased survival for critically injured patient with penetrating abdominal trauma. There has been a slower adoption of a damage control strategy for thoracic trauma despite the considerable mortality associated with emergent thoracotomy for patients in profound shock. We postulated admission physiology, not blood pressure or shock index, would identify patients who would benefit from thoracic damage control. Study Design: Retrospective trauma registry review from 2002 to 2017 at a busy, urban trauma center. 301 patients with penetrating thoracic trauma operated on within 6 hours of admission were identified. Of those 66 (21.9%) required thoracic damage control and comprise the study population. Results: Compared to the non-damage control group, the 66 damage control patients had significantly higher ISS, chest AIS, lactate and base deficit, and lower pH and temperature. In addition, the DCTS group had significantly more gunshot wounds, transfusions, concomitant laparotomies, vasoactive infusions, and shorter time to the operating room. Notably, however, there were no significant differences in admission systolic blood pressure or shock index between the groups. Once normal physiology was restored, chest closure was performed 1.7 (0.7) days after the index operation. Mortality for thoracic damage was 15.2%, significantly higher than the 4.3% in the non-damage control group. Over two-thirds of damage control deaths occurred prior to chest closure. Conclusions: Mortality in this series of severely injured, profoundly physiologically altered patients undergoing thoracic damage control is substantially lower than previously reported. Rather than relying on blood pressure and shock index, early recognition of shock identifies patients in whom thoracic damage control is beneficial. Address reprint requests to James V. O’Connor, MD, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S Greene Street, Baltimore, MD 21201. E-mail: james.oconnor@som.umaryland.edu Received 30 August, 2019 Revised 18 September, 2019 Accepted 24 October, 2019 The authors report no conflicts of interest. © 2019 by the Shock Society

Toll like receptor 2 and 9 expression on circulating neutrophils is associated with increased mortality in critically ill patients Background: Toll-like receptors (TLRs) play an important role in inflammatory processes in critically ill patients by binding to pathogen-associated molecular patterns and danger-associated molecular patterns (DAMPs). Whether neutrophil or monocyte TLR expression patterns are associated with outcome in critical illness is unknown. Objectives: To answer this question, we conducted a prospective, observational study including 215 consecutive patients admitted to a medical ICU at a tertiary care center. Methods: Blood was drawn at admission and expression of TLR-2, TLR-4, and TLR-9 on neutrophils and monocytes were analyzed by flow cytometry. Results: Median Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 19, and 30-day mortality was 26%. TLR-2 expression on neutrophils was associated with APACHE II, Simplified Acute Physiology Score II, and Sepsis-related Organ Failure Assessment score. TLR-2 (P < 0.001) and TLR-9 (P < 0.05) expression on neutrophils was significantly higher in nonsurvivors. In contrast, neutrophil TLR-4 expression and monocyte TLR expression were not associated with survival. Neutrophil TLR-2 (OR 3.8; 95% CI 1.4–10.2; P < 0.05) and TLR-9 (OR 4.0; 95% CI 2.0–8.1; P < 0.001) expression in the third tertile predicted mortality independent from APACHE II, serum lactate, serum creatinine, and procalcitonin, respectively. Conclusion: We provide evidence for prognostic properties of neutrophil TLR-2 and TLR-9 expression regarding 30-day mortality in unselected critically ill patients, independent from baseline clinical characteristics, and laboratory values. These findings suggest that specific TLR-dependent activation of the innate immune system via neutrophils possibly caused by cell damage and release of otherwise intracellular components may play a significant role in the pathophysiology of critical illness. Address reprint requests to Walter S. Speidl, MD, Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria. E-mail: Walter.Speidl@meduniwien.ac.at Received 7 August, 2019 Revised 28 August, 2019 Accepted 7 October, 2019 Conflicts of interest: the authors declare no conflict of interest. Availability of materials and data: The datasets generated during and/or analyzed during the present study are available from the corresponding author on reasonable request. Author contributions: K.A.K. and W.S.S. designed the study and were involved in data analysis and interpretation. A.N., K.H., J.W., and G.H. were strongly involved in analysis and interpretation of data. D.F.D., C.Z., M.K., and S.P.K. were strongly involved in data acquisition. M.L., K.A.K., and W.S.S. drafted the manuscript. D.F.D., C.Z., M.K., S.P.K., A.N., K.H., J.W., and G.H. critically revised the manuscript. All authors gave final approval of the version submitted. Each author has participated sufficiently in the work to take public responsibility for appropriate portions of the content and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. Competing interests: All authors declare no competing interests. © 2019 by the Shock Society

The Effect of Burn Resuscitation Volumes on the Gut Microbiome in a Swine Model Introduction: While recent reports underscore the significance of the gut microbiome (GM) in health and disease, its importance in burn outcomes remains unclear. Moreover, aggressive intravenous (IV) fluid resuscitation of patients may alter intestinal flora. Herein, we describe GM changes following a large burn in swine randomized to different volumes of IV Lactated Ringers’ (LR). Methods: Anesthetized Yorkshire swine sustained 40% Total body surface area full-thickness burns and were randomized to different volumes of IV LR: none (n = 3), 15 mL/kg/day (Low; n = 6), or 80 mL/kg/day (High; n = 6). At baseline and days 1 and 2, fecal swabs were collected for 16 s rDNA sequencing. Proximal jejunum was collected immediately after euthanasia (day 2) for western blot, histopathology, and cytokine analyses. Results: Burns produced significant shifts in β-diversity and non-significant reductions in α-diversity that did not recover regardless of treatment group. Burn-induced increases in Proteobacteria and decreases in Firmicutes were attenuated by IV fluids in a dose-dependent manner, and also correlated with α-diversity. IV fluids caused a dose-dependent increase in Bacteroides and prevented a transient increase in the opportunistic pathogen Haemophilus parainfluenzae. While high volumes of IV fluids increased intestinal Hsp70 levels (p = 0.0464), they reduced SGLT1 (p = 0.0213) and caspase3 (p = 0.0139) levels. IV fluids elicited a non-specific cytokine response however Bacteroidetes levels correlated with intestinal IL18 levels (p = 0.0166, R2 = 0.4201). Conclusions: We present the first report on the gut microbiome in a porcine burn model, and present data to suggest that IV fluids may influence GM and gut functional proteins following a burn. Overall, burn injury results GM diversity shifts, which may expose diagnostic and/or therapeutic targets to improve outcomes. Address reprint requests to David M. Burmeister, PhD, US Army Institute of Surgical Research, Office. E-mail: David.m.burmeister3.civ@mail.mil Received 7 August, 2019 Revised 23 August, 2019 Accepted 27 September, 2019 Funded by US Army Medical Research Development Command W81XWH-16-2-0041. Competing Interests: The authors declare no competing interests. Authors’ Contributions: DB, SN and MD conceived the study. MM and DB prepared the manuscript. BG, JL and DB performed the animal experiments. MM analyzed the sequencing data. CW, JL, and JPL performed histological, imaging, and Western Blot analyses. All authors read and approved the final manuscript. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). © 2019 by the Shock Society

Hydrogen Gas Inhalation Attenuates Endothelial Glycocalyx Damage and Stabilizes Hemodynamics in a Rat Hemorrhagic Shock Model Background: Hydrogen gas (H2) inhalation during hemorrhage stabilizes post-resuscitation hemodynamics, improving short-term survival in a rat hemorrhagic shock and resuscitation (HS/R) model. However, the underlying molecular mechanism of H2 in HS/R is unclear. Endothelial glycocalyx (EG) damage causes hemodynamic failure associated with HS/R. In this study, we tested the hypothesis that H2 alleviates oxidative stress by suppressing xanthine oxidoreductase (XOR) and/or preventing tumor necrosis factor-alfa (TNF-α)-mediated syndecan-1 shedding during EG damage. Methods: HS/R was induced in rats by reducing mean arterial pressure (MAP) to 35 mm Hg for 60 min followed by resuscitation. Rats inhaled oxygen or H2 + oxygen after achieving shock either in the presence or absence of an XOR inhibitor (XOR-I) for both groups. In a second test, rats received oxygen alone or anti-tumor necrosis factor (TNF)-α monoclonal antibody with oxygen or H2. Two hours after resuscitation, XOR activity, purine metabolites, cytokines, syndecan-1 were measured and survival rates were assessed 6 h after resuscitation. Results: H2 and XOR-I both suppressed MAP reduction and improved survival rates. H2 did not affect XOR activity and the therapeutic effects of XOR-I and H2 were additive. H2 suppressed plasma TNF-α and syndecan-1 expression; however, no additional H2 therapeutic effect was observed in the presence of anti-TNF-α monoclonal antibody. Conclusions: H2 inhalation after shock stabilized hemodynamics and improved survival rates in an HS/R model independent of XOR. The therapeutic action of H2 was partially mediated by inhibition of TNF-α-dependent syndecan-1 shedding. Address for correspondence: Motoaki Sano, M.D, PhD, 35 Shinanomachi Shinjuku-ku Tokyo 160-8582, Japan, Department of Cardiology, Keio University School of Medicine, The center for molecular hydrogen medicine, Keio University. E-mail: msano@keio.jp. Received 7 August, 2019 Revised 27 August, 2019 Accepted 27 September, 2019 Reprints will not be ordered. Conflicts of Interest and Source of Funding: The research was supported by a research grant from Taiyo Nissan Corporation to M.Sa., and xanthine oxidoreductase inhibitor (Topiroxat) was provided by Sanwa Kagaku Kenkyusho Co., Ltd. T.T, M.Sa., and M.Su. received a travel grant from the Taiyo Nippon Sanso Corporation. The remaining authors declare no conflicts of interest. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). © 2019 by the Shock Society

The Shock Society 2019–2021 Strategic Plan No abstract available

Cardiac Dysfunction in Severely Burned Patients: Current Understanding of Etiology, Pathophysiology and Treatment Patients that experience severe burn injuries face a massive inflammatory response resulting in hemodynamic and cardiovascular complications. Even after immediate and appropriate resuscitation, removal of burn eschar and covering of open areas, burn patients remain at high risk for serious morbidity and mortality. As a result of the massive fluid shifts following the initial injury, along with large volume fluid resuscitation, the cardiovascular system is critically affected. Further, increased inflammation, catecholamine surge and hypermetabolic syndrome impacts cardiac dysfunction, which worsens outcomes of burn patients. This review aimed to summarize the current knowledge about the effect of burns on the cardiovascular system. A comprehensive search of the PubMed and Embase databases and manual review of articles involving effects of burns on the cardiovascular system was conducted. Many burn units use multi-modal monitors (e.g. transpulmonary thermodilution) to assess hemodynamics and optimize cardiovascular function. Echocardiography is often used for additional evaluations of hemodynamically unstable patients to assess systolic and diastolic function. Due to its non-invasive character, echocardiography can be repeated easily, which allows to follow patients longitudinally. The use of anabolic and anti-catabolic agents has been shown to be beneficial for short- and long-term outcomes of burn survivors. Administration of propranolol (non-selective β-receptor antagonist) or oxandrolone (synthetic testosterone) for up to 12 months post-burn counteracts hypermetabolism during hospital stay and improves cardiac function. A comprehensive understanding of how burns lead to cardiac dysfunction and new therapeutic options could contribute to better outcomes in this patient population. Address reprint requests to Christian Tapking, MD, MMS, Department of Surgery, University of Texas Medical Branch Galveston, 301 University Blvd, Galveston, TX 77555, USA. E-mail: christian.tapking@googlemail.com Received 21 August, 2019 Revised 11 September, 2019 Accepted 2 October, 2019 Conflicts of interest: The authors declare that they have no conflicts of interest. Funding: None. © 2019 by the Shock Society

Hemophagocytic Lymphohistiocytosis in Critically Ill Patients Background: Hemophagocytic lymphohistiocytosis (HLH), an uncontrolled overactivation of the immune system, is well characterized in pediatric patients, yet, much less is known about this life-threatening condition in adult patients. As HLH is often complicated by organ failure, patients will require admission to the intensive care unit for organ support therapy. However, recognition of HLH patients in the ICU is challenged by the clinical overlap with sepsis. Here, we analyze HLH patients to better understand its clinical presentation, diagnosis and treatment. Methods: For the purpose of this retrospective observational study, we searched for suspected and diagnosed adult HLH of all patients admitted to at least one adult surgical, anesthesiological or medical ICU between January 2006 and August 2018 at the university hospital Charité – Universitätsmedizin Berlin. All cases were reviewed by two HLH experts, who confirmed or declined the diagnosis. Results: Of 6340 ICU patients with ferritin measurement, 40 suffered from HLH (0.63%). Of these, in-hospital mortality was 60.0% over all cases, which was highest in malignancy-associated HLH (71.4%). Infections were identified as most common triggers (42.5%). A variety of 19 different treatment strategies were applied. Non-survivors showed higher ferritin at diagnosis compared to survivors (p = 0.021), which was also seen in multivariable analyses. A minimum ferritin of 4083 μg/L after diagnosis was most predictive for 30-day mortality (AUC 0.888, 95% CI 0.771–1.000; sensitivity 93.8%, specificity 78.9%). Conclusions: Mortality in adult HLH patients in the ICU is high, particularly in malignancy-associated HLH. Infections are the most frequent HLH triggers in critically ill patients. At present, there is no standardized treatment for HLH in adult patients available. Assessment of ferritin is valuable for diagnosis, prognosis, and treatment monitoring. Trial registration: The study was registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016. Address reprint requests to Gunnar Lachmann, MD, Department of Anesthesiology and Operative Intensive Care Medicine (CCM, CVK) Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health Augustenburger Platz 1, D-13353 Berlin, Germany. E-mail: gunnar.lachmann@charite.de. Received 9 August, 2019 Revised 26 August, 2019 Accepted 17 September, 2019 Ethics approval: Ethics approval was obtained from the institutional review board (Ethikkommission der Charité – Universitätsmedizin Berlin, EA1/176/16). The study was registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016. Consent for publication: Not applicable. Availability of data and material: Due to legal restrictions imposed by the data protection commissioner of the Charité – Universitätsmedizin Berlin, public sharing of study data with other researchers or entities is not allowed. Requests may be sent to dai-researchdata@charite.de. Competing interests: The authors declare that they have no competing interests. Funding: Gunnar Lachmann is participant of the BIH Charité Clinician Scientist Program funded by the Charité – Universitätsmedizin Berlin and the Berlin Institute of Health (BIH). Authors’ contributions: Conceived and designed the study: CK, GL. Analyzed the data: CK, FSS, GV, TSGL. Wrote the manuscript: CK, GJ, GL. Commented on the manuscript: all authors. The authors declare that they have no competing interests. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). © 2019 by the Shock Society

Neonatal Sepsis Alters the Excitability of Regular Spiking Cells in the Nucleus of the Solitary Tract in Rats Objective: Sepsis is a leading cause of mortality and morbidity in infants. Although the measures of autonomic dysfunction (e.g. reduced heart rate variability) predict mortality in sepsis, the mechanism of sepsis-induced autonomic dysfunction has remained elusive. The nucleus of the solitary tract hjh(NTS) is a vital structure for the integrated autonomic response to physiological challenges. In the present study we hypothesized that sepsis alters the excitability of NTS neurons in a rat model of neonatal sepsis (14-day old rats). Methods and results: Sepsis was induced by intraperitoneal injection of cecal slurry (CS) in rat neonates. The presence of autonomic dysfunction was confirmed by observing a significant reduction in both short-term and long-term heart rate variably following CS injection. We investigated the effect of polymicrobial sepsis on the electrophysiological properties of the medial NTS neurons using a whole cell patch clamp recording. Our results showed that the resting membrane potential in regular spiking neurons was significantly less polarized in the septic group (-37.6 ± 1.76 mv) when compared with the control group (-54.7 ± 1.73 mv, P < 0.001). The number of spontaneous action potentials in the septic group, was also significantly higher than the control group (P < 0.05). In addition, the frequency and amplitude of the spontaneous excitatory post synaptic potentials (EPSPs) was significantly higher in neurons recorded in the septic group (P < 0.001). Interestingly, regular spiking cells in the CS group exhibited a rebound action potential following hyperpolarization. Injection of depolarizing currents was associated with lower first spike latency and changes in rise slope of action potential (P < 0.001). Conclusions: We showed that polymicrobial sepsis increases the excitability of regular spiking cells in the medial NTS. These alterations can potentially affect neural coding and thus may contribute to an abnormal homeostatic or allostatic physiological response to sepsis and systemic inflammation. Address reprint requests to Alireza Mani, MD, PhD, and Saeed Semnanian, MD, PhD, University College London, London, London United Kingdom. E-mail: a.r.mani@ucl.ac.uk; ssemnan@modares.ac.ir. Received 15 July, 2019 Revised 17 August, 2019 Accepted 13 September, 2019 Conflicts of interest: none Disclosure statement: Authors declare no conflict of interest. The funder had no influence on the study design or analysis or on the content of this article Funding: This study was supported by a grant from Tarbiat Modares University (PhD project grant to Golnar Eftekhari: g.eftekhari@modares.ac.ir). Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). © 2019 by the Shock Society