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IntroductionAccurate triage is an important first step to effectively manage the clinical treatment of severe cases in a pandemic outbreak. In the current COVID-19 global pandemic, there is a lack of reliable clinical tools to assist clinicians to perform accurate triage. Host response biomarkers have recently shown promise in risk stratification of disease progression; however, the role of these biomarkers in predicting disease progression in patients with COVID-19 is unknown. Here, we present a protocol outlining a prospective validation study to evaluate the biomarkers’ performance in predicting clinical outcomes of patients with COVID-19.Methods and analysisThis prospective validation study assesses patients infected with COVID-19, in whom blood samples are prospectively collected. Recruited patients include a range of infection severity from asymptomatic to critically ill patients, recruited from the community, outpatient clinics, emergency departments and hospitals. Study samples consist of peripheral blood samples collected into RNA-preserving (PAXgene/Tempus) tubes on patient presentation or immediately on study enrolment. Real-time PCR (RT-PCR) will be performed on total RNA extracted from collected blood samples using primers specific to host response gene expression biomarkers that have been previously identified in studies of respiratory viral infections. The RT-PCR data will be analysed to assess the diagnostic performance of individual biomarkers in predicting COVID-19-related outcomes, such as viral pneumonia, acute respiratory distress syndrome or bacterial pneumonia. Biomarker performance will be evaluated using sensitivity, specificity, positive and negative predictive values, likelihood ratios and area under the receiver operating characteristic curve.Ethics and disseminationThis research protocol aims to study the host response gene expression biomarkers in severe respiratory viral infections with a pandemic potential (COVID-19). It has been approved by the local ethics committee with approval number 2020/ETH00886. The results of this project will be disseminated in international peer-reviewed scientific journals.

Investigation of the effects of hyperoxia during resuscitation from hemorrhagic shock in swine with preexisting coronary artery disease.Prospective, controlled, randomized trial.University animal research laboratory.Nineteen hypercholesterolemic pigs with preexisting coronary artery disease.Anesthetized, mechanically ventilated, and surgically instrumented pigs underwent 3 hours of hemorrhagic shock (removal of 30% of the calculated blood volume and subsequent titration of mean arterial blood pressure ≈40 mm Hg). Postshock resuscitation (48 hr) comprised retransfusion of shed blood, crystalloids (balanced electrolyte solution), and norepinephrine support. Pigs were randomly assigned to "control" (FIO2 0.3, adjusted for arterial oxygen saturation ≥ 90%) and "hyperoxia" (FIO2 1.0 for 24 hr) groups.Before, at the end of shock and every 12 hours of resuscitation, datasets comprising hemodynamics, calorimetry, blood gases, cytokines, and cardiac and renal function were recorded. Postmortem, organs were sampled for immunohistochemistry, western blotting, and mitochondrial high-resolution respirometry. Survival rates were 50% and 89% in the control and hyperoxia groups, respectively (p = 0.077). Apart from higher relaxation constant τ at 24 hours, hyperoxia did not affect cardiac function. However, troponin values were lower (2.2 [0.9-6.2] vs 6.9 [4.8-9.8] ng/mL; p0.05) at the end of the experiment. Furthermore, hyperoxia decreased cardiac 3-nitrotyrosine formation and increased inducible nitric oxide synthase expression. Plasma creatinine values were lower in the hyperoxia group during resuscitation coinciding with significantly improved renal mitochondrial respiratory capacity and lower 3-nitrotyrosine formation.Hyperoxia during resuscitation from hemorrhagic shock in swine with preexisting coronary artery disease reduced renal dysfunction and cardiac injury, potentially resulting in improved survival, most likely due to increased mitochondrial respiratory capacity and decreased oxidative and nitrosative stress. Compared with our previous study, the present results suggest a higher benefit of hyperoxia in comorbid swine due to an increased susceptibility to hemorrhagic shock.

As controversy persists regarding the benefits of mechanical circulatory support in septic shock with a predominantly vasoplegic phenotype, preclinical studies may provide a useful alternative to fill the actual knowledge gap. Here, we investigated the physiologic responses to venoarterial extracorporeal membrane oxygenation therapy (VA-ECMO) in a clinically relevant porcine peritonitis-induced model of refractory vasodilatory septic shock. In 12 anesthetized, mechanically ventilated, and instrumented domestic pigs, septic shock was induced by intraperitoneally inoculating autologous feces. After reaching the threshold for refractory vasodilatory shock (norepinephrine dose ≥1 μg/kg/min), the pigs were randomized into the conservative treatment group (control) or the VA-ECMO group (target flow 100 mL/kg/min). The time to develop refractory vasodilatory shock was similar in both groups (18.8 h in the ECMO group, 18.1 h in the control group). There was no difference between the groups in terms of time to death measured from the point of reaching the predefined vasopressor threshold (7.1 h for the ECMO group, 7.9 h for the control group). The initiation of ECMO resulted in a markedly increased fluid and vasopressor support. Although treatment with ECMO compromised neither renal nor carotid blood flow initially, both progressively decreased later during the experiment. The pattern of sepsis-induced multiorgan injury, alterations in energy metabolism, and the systemic inflammatory response were remarkably similar between both groups. In conclusion, the application of VA-ECMO in this model of peritonitis-induced refractory vasodilatory septic shock aggravated hemodynamic deterioration. Our findings contribute to increasing equipoise with respect to the clinical utility of VA-ECMO in refractory vasodilatory shock.

Although the burden of septic acute kidney injury continues to increase, the molecular pathogenesis remains largely obscure. The aim of this exploratory study was a discovery-driven analysis of dynamic kidney tissue protein expression changes applied for the first time in a classic large mammal model of sepsis. To achieve this goal, analyses of protein expression alterations were performed in serial samples of kidney cortical biopsies (before, 12 and 22 h of sepsis) in mechanically ventilated pigs challenged with continuous infusion of pseudomonas aeruginosa and compared with sham-operated control data. Global protein expression was analyzed using two-dimensional gel electrophoresis and mass spectrometry-based proteomics. Normodynamic sepsis was associated with 43% reduction in glomerular filtration. The exposure to surgical stress per se altered the renal protein expression profile, while sepsis induced distinct and highly dynamic proteome evolution shifting the balance toward cellular distress phenotype. We identified 20 proteins whose expression changes discriminated effects of sepsis from those induced by surgery. The data implicate endoplasmic reticulum stress, oxidative stress, mitochondrial energy metabolism, immune/inflammatory signaling, and tubular transport as major activated pathways. Thus, by coupling the power of sequential tissue proteomics with whole-animal physiological studies, our study helped to establish a first global overview of critical renal proteomic events occurring during surgical trauma and early sepsis in a porcine model. The study supports the notion that multiple potentially subtle and even transient changes in several proteins which are members of key functional interrelated systems appear to play a role in septic acute kidney injury.

Background: Severe sepsis/septic shock is associated with high mortality. In Central Europe, there is a dearth of information on the prevalence and treatment of severe sepsis. The EPOSS (Data-based Evaluation and Prediction of Outcome in Severe Sepsis) project launched in 2011 was aimed at collecting data on patients with severe sepsis/septic shock. Methods: The EPOSS study processes data from the EPOSS project database, and is a retrospective, multicentre, observational study. This included all consecutive patients aged 18 and over who were admitted to participating ICUs from 1 January 2011 to 5 November 2013 and met the inclusion criteria of severe sepsis/septic shock. The primary endpoint was to analyse the relationship between in-hospital mortality (either in ICU or after discharge from ICU) and the type and number of fulfilled diagnostic and treatment interventions during the first 6 h after the diagnosis of severe sepsis/septic shock. Results: The collected dataset involved 1082 patients meeting the criteria of severe sepsis/septic shock. Following data validation, a final dataset of 897 patients was obtained. The average age of the patient group was 64.7 years; mortality at discharge from EPOSS ICUs was 35.5% and from hospital 40.7%. Of the 10 evaluated diagnostic and treatment interventions within the initial 6 hours of identifying severe sepsis/septic shock (i.e. fulfilment of SSC bundles), four or five diagnostic and treatment interventions were administered to 58.4% patients. Combined diagnostic and treatment interventions associated with the lowest in-hospital mortality were: CVP of ≥8-12 mm Hg & MAP of ≥65 mm Hg & Urine output at ≥0.5 mL/kg/h & Lactate of ≤4.0 mmol/L & Initial lactate measured & Antibiotics in the first hour. Lactate at

AIM The aim of our prospective study was to evaluate the development of postpartum anal incontinence in patients with inflammatory bowel disease (IBD) compared to healthy women. MATERIAL AND METHODS Patients with IBD and healthy controls enrolled in the study from January 1st 2013 to November 30th 2016 and filled in the anal incontinence questionnaire in the beginning of pregnancy and after vaginal delivery. The results were statistically processed using suitable tests. RESULTS A total of 57 women were enrolled, 17 (29.8 %) with ulcerative colitis, 23 (40.4 %) with Crohn's disease, and 17 (29.8 %) healthy controls. Incidence of postpartum anal incontinence is comparable across all groups; there was no statistically significant difference between the IBD and control groups (Kruskal-Wallis test by ranks with Dunn correction, non-significant). Postpartum anal incontinence was strongly correlated with the extent of perineal injury (r = 0.80; p < 0.0001; Pearson's linear correlation). CONCLUSIONS Women with inflammatory bowel disease in remission do not exhibit higher incidence of postpartum anal incontinence (PPAI) compared to healthy controls; the key correlate of PPAI appears to be the extent of obstetric injury, consistently across all study groups. These results suggest that concerns about postpartum anal incontinence development should not be an indication for Caesarean section in IBD patients (Tab. 6, Fig. 1, Ref. 34).

We previously demonstrated beneficial effects of 22 h of hyperoxia following near-lethal porcine hemorrhagic shock, whereas therapeutic hypothermia was detrimental. Therefore, we investigated whether shorter exposure to hyperoxia (12 h) would still improve organ function, and whether 12 h of hypothermia with subsequent rewarming could avoid deleterious effects after less severe hemorrhagic shock.Twenty-seven anesthetized and surgically instrumented pigs underwent 3 h of hemorrhagic shock by removal of 30% of the blood volume and titration of the mean arterial blood pressure (MAP) to 40 mm Hg. Post-shock, pigs were randomly assigned to control, hyperoxia (FIO2 100% for 12 h) or hypothermia group (34°C core temperature for 12 h with subsequent rewarming). Before, at the end of shock, after 12 and 23 h of resuscitation, data sets comprising hemodynamics, blood gases, and parameters of inflammation and organ function were acquired. Postmortem, kidney samples were collected for immunohistochemistry and western blotting.Hyperoxia exerted neither beneficial nor detrimental effects. In contrast, mortality in the hypothermia group was significantly higher compared with controls (67% vs. 11%). Hypothermia impaired circulation (MAP 64 (57;89) mm Hg vs. 104 (98; 114) mm Hg) resulting in metabolic acidosis (lactate 11.0 (6.6;13.6) mmol L vs. 1.0 (0.8;1.5) mmol L) and reduced creatinine clearance (26 (9;61) mL min vs. 77 (52;80) mL min) compared to the control group after 12 h of resuscitation. Impaired kidney function coincided with increased renal 3-nitrotyrosine formation and extravascular albumin accumulation.In conclusion, hyperoxia proved to be safe during resuscitation from hemorrhagic shock. The lacking organ-protective effects of hyperoxia compared to resuscitation from near-lethal hemorrhage suggest a dependence of the effectiveness of hyperoxia from shock severity. In line with our previous report, therapeutic hypothermia (and rewarming) was confirmed to be detrimental most likely due to vascular barrier dysfunction.

Depression of heart-rate variability (HRV) in conditions of systemic inflammation has been shown in both patients and experimental animal models and HRV has been suggested as an early indicator of sepsis. The sensitivity of HRV-derived parameters to the severity of sepsis, however, remains unclear. In this study we modified the clinically relevant porcine model of peritonitis-induced sepsis in order to avoid the development of organ failure and to test the sensitivity of HRV to such non-severe conditions. In 11 anesthetized, mechanically ventilated and instrumented domestic pigs of both sexes, sepsis was induced by fecal peritonitis. The dose of feces was adjusted and antibiotic therapy was administered to avoid multiorgan failure. Experimental subjects were screened for 40 h from the induction of sepsis. In all septic animals, sepsis with hyperdynamic circulation and increased plasma levels of inflammatory mediators developed within 12 h from the induction of peritonitis. The sepsis did not progress to multiorgan failure and there was no spontaneous death during the experiment despite a modest requirement for vasopressor therapy in most animals (9/11). A pronounced reduction of HRV and elevation of heart rate developed quickly (within 5 h, time constant of 1.97 ± 0.80 h for HRV parameter TINN) upon the induction of sepsis and were maintained throughout the experiment. The frequency domain analysis revealed a decrease in the high-frequency component. The reduction of HRV parameters and elevation of heart rate preceded sepsis-associated hemodynamic changes by several hours (time constant of 11.28 ± 2.07 h for systemic vascular resistance decline). A pronounced and fast reduction of HRV occurred in the setting of a moderate experimental porcine sepsis without organ failure. Inhibition of parasympathetic cardiac signaling probably represents the main mechanism of HRV reduction in sepsis. The sensitivity of HRV to systemic inflammation may allow early detection of a moderate sepsis without organ failure. Impact statement A pronounced and fast reduction of heart-rate variability occurred in the setting of a moderate experimental porcine sepsis without organ failure. Dominant reduction of heart-rate variability was found in the high-frequency band indicating inhibition of parasympathetic cardiac signaling as the main mechanism of heart-rate variability reduction. The sensitivity of heart-rate variability to systemic inflammation may contribute to an early detection of moderate sepsis without organ failure.

Background Additional urinary biomarkers for diabetic nephropathy (DN) are needed, providing early and reliable diagnosis and new insights into its mechanisms. Rigorous selection criteria and homogeneous study population may improve reproducibility of the proteomic approach. Methods Long-term type 1 diabetes patients without metabolic comorbidities were included, 11 with sustained microalbuminuria (MA) and 14 without MA (nMA). Morning urine proteins were precipitated and resolved by 2D electrophoresis. Principal component analysis (PCA) and Projection to latent structures discriminatory analysis (PLS-DA) were adopted to assess general data validity, to pick protein fractions for identification with mass spectrometry (MS), and to test predictive value of the resulting model. Results Proteins (n = 113) detected in more than 90% patients were considered representative. Unsupervised PCA showed excellent natural data clustering without outliers. Protein spots reaching Variable Importance in Projection score above 1 in PLS (n = 42) were subjected to MS, yielding 33 positive identifications. The PLS model rebuilt with these proteins achieved accurate classification of all patients (R2X = 0.553, R2Y = 0.953, Q2 = 0.947). Thus, multiple earlier recognized biomarkers of DN were confirmed and several putative new biomarkers suggested. Among them, the highest significance was met in kininogen-1. Its activation products detected in nMA patients exceeded by an order of magnitude the amount found in MA patients. Conclusions Reducing metabolic complexity of the diseased and control groups by meticulous patients’ selection allows to focus the biomarker search in DN. Suggested new biomarkers, particularly kininogen fragments, exhibit the highest degree of correlation with MA and substantiate validation in larger and more varied cohorts. Electronic supplementary material The online version of this article (doi:10.1186/s12882-017-0519-4) contains supplementary material, which is available to authorized users.

The aim of this study was to identify pitfalls in establishing the diagnosis of celiac disease (CD) in patients with a history of lymphoma. A total of 103 patients with a history of lymphoma had anti-tissue transglutaminase antibodies (atTGA) and their class A, G, and M immunoglobulin (IgA, IgG) levels determined. Patients with atTGA positivity underwent enterobiopsy and CD-associated HLA locus testing. The mean age of patients was 55 ( ± 13.5) years. The predominant lymphoma types included B-type non-Hodgkin’s lymphoma (B-NHL, 66 %), T-type NHL (8 %), and Hodgkin’s lymphoma (26 %). Serological positivity was documented in 3.9 % of cases; one patient had the diagnosis of CD confirmed by enterobiopsy. In 11 patients (10.7 %), IgA levels were decreased to a various extent; of these patients, 10 were shown to have also their IgG levels decreased. The median time from follow-up to blood collection was 58 (32–104) months. The decrease in immunoglobulin levels correlated with a more advanced stage of the tumor (Ann Arbor III–IV) at the time of diagnosis [1.4 (0.9–2.0) g/l versus 2.4 (1.5–3.0) g/l for IgA, p = 0.0001; and 9.4 (7.2–11.5) g/l versus 11.2 (10.3–12.3) g/l for IgG, p = 0.001] and older age [65 (54–72) years versus 55 (44–61) years for IgA, p = 0.04; and 69 (59–74) years versus 53 (43–61) years for IgG, p = 0.0001]. Rituximab therapy in B-NHL patients had no effect on the subsequent incidence of decreased IgA levels. Reduced IgA and IgG levels represent important factors contributing to the low detection rate of serological screening for CD in patients with a history of lymphoma.

Purpose: The purpose of the study is to understand what clinicians believe defines fluid bolus therapy (FBT) and the expected response to such intervention. Methods: We asked intensive care specialists in 30 countries to participate in an electronic questionnaire of their practice, definition, and expectations of FBT. Results: We obtained 3138 responses. Despite much variation, more than 80% of respondents felt that more than 250 mL of either colloid or crystalloid fluid given over less than 30 minutes defined FBT, with crystalloids most acceptable. The most acceptable crystalloid and colloid for use as FBT were 0.9% saline and 4% albumin solution, respectively. Most respondents believed that one or more of the following physiological changes indicates a response to FBT: a mean arterial pressure increase greater than 10 mm Hg, a heart rate decrease greater than 10 beats per minute, an increase in urinary output by more than 10 mL/h, an increase in central venous oxygen saturation greater than 4%, or a lactate decrease greater than 1 mmol/L. Conclusions: Despite wide variability between individuals and countries, clear majority views emerged to describe practice, define FBT, and identify a response to it. Further investigation is now required to describe actual FBT practice and to identify the magnitude and duration of the physiological response to FBT and its relationship to patient-centered outcomes., Facultad de Ciencias Médicas

Objective: To test the hypothesis whether pure oxygen ventilation is equally safe and beneficial in fully developed fecal peritonitis-induced septic shock as hyperoxia initiated at the induction of sepsis. Design: Prospective, randomized, controlled, experimental study with repeated measures. Setting: Animal research laboratory at a university medical school. Subjects: Twenty anesthetized, mechanically ventilated, and instrumented pigs. Interventions: Twelve hours after induction of fecal peritonitis by inoculation of autologous feces, swine, which were resuscitated with hydroxyethyl starch and norepinephrine to maintain mean arterial pressure at baseline values, were ventilated randomly with an Flo 2 required to keep Sao 2 >90% (controls: n = 10) or Flo 2 1.0 (hyperoxia, n = 10) during the next 12 hrs. Measurements and Main Results: Despite similar hemodynamic support (hydroxyethyl starch and norepinephrine doses), systemic and regional macrocirculatory and oxygen transport parameters, hyperoxia attenuated pulmonary hypertension, improved gut microcirculation (ileal mucosal laser Doppler flowmetry) and portal venous acidosis, prevented the deterioration in creatinine clearance (controls 61 (44;112), hyperoxia: 96 (88;110) ml·min ―1 , p = .074), and attenuated the increase in blood tumor necrosis factor-α concentrations (p = .045 and p = .112 vs. controls at 18 hrs and 24 hrs, respectively). Lung and liver histology (hematoxyline eosine staining) were comparable in the two groups, but hyperoxia reduced apoptosis (Tunel test) in the liver (4 (3;8) vs. 2 (1;5) apoptotic cells/field, p = .069) and the lung (36 (31;46) vs. 15 (13;17) apoptotic cells/field, p < .001). Parameters of lung function, tissue antioxidant activity, blood oxidative and nitrosative stress (nitrate + nitrite, 8-isoprostane levels; deoxyribonucleic acid (DNA) damage measured using the comet assay) were not further affected during hyperoxia. Conclusions: When compared with the previous report on hyperoxia initiated simultaneously with induction of sepsis, i.e., using a pretreatment approach, pure oxygen ventilation started when porcine fecal peritonitis-induced septic shock was fully developed proved to be equally safe with respect to lung function and oxidative stress, but exerted only moderate beneficial effects.

Critical illness, such as sepsis or septic shock with multiple organ dysfunction syndrome, is the leading cause of morbidity and mortality in intensive care units. The complexity of critical illness requires a robust methodology to explore the underlying mechanisms. Proteomics represents a powerful postgenomic biotechnology used for simultaneous examination of a large number of proteins or the proteome. Recent progress in proteomic techniques allows thorough evaluation of molecular changes associated with critical illness, thereby permitting to identify novel biomarkers and therapeutic targets. This review provides an update on the recent progress and potential of rapidly evolving proteomics approach to facilitate new discoveries in the field of critical care medicine.

Sepsis is a systemic response to infection commonly found in critically ill patients and is associated with multi-organ failure and high mortality rate. Its pathophysiology and molecular mechanisms are complicated and remain poorly understood. In the present study, we performed a proteomics investigation to characterize early host responses to sepsis as determined by an altered plasma proteome in a porcine model of peritonitis-induced sepsis, which simulated several clinical characteristics of human sepsis syndrome. Haemodynamics, oxygen exchange, inflammatory responses, oxidative and nitrosative stress, and other laboratory parameters were closely monitored. Plasma samples were obtained from seven pigs before and 12 h after the induction of sepsis, and plasma proteins were resolved with two-dimensional gel electrophoresis ( n =7 gels/group; before being compared with during sepsis). The resolved proteins were stained with the SYPRO Ruby fluorescence dye and subjected to quantitative and comparative analyses. From approx. 1500 protein spots visualized in each gel, levels of 36 protein spots were significantly altered in the plasma of animals with sepsis (sepsis/basal ratios or degrees of change ranged from 0.07 to 21.24). Q-TOF (quadrupole–time-of-flight) MS and MS/MS (tandem MS) identified 30 protein forms representing 22 unique proteins whose plasma levels were increased, whereas six forms of five unique proteins were significantly decreased during sepsis. The proteomic results could be related to the clinical features of this animal model, as most of these altered proteins have important roles in inflammatory responses and some of them play roles in oxidative and nitrosative stress. In conclusion, these findings may lead to a better understanding of the pathophysiology and molecular mechanisms underlying the sepsis syndrome. Abbreviations: 2-D, two-dimensional; ACN, acetonitrile; BP, blood pressure; CO, cardiac output; CVP, central venous pressure; DO2, oxygen delivery; DTT, dithiotheitol; FiO2, fraction of inspired oxygen; IEF, isoelectric focusing; IL, interleukin; LPS, lipopolysaccharide; Q-TOF, quadrupole–time-of-flight; MS/MS, tandem MS; NCBI, National Center for Biotechnology Information; NOx, nitrate/nitrite; PAOP, pulmonary artery occlusion pressure; PCO2, partial pressure of carbon dioxide; PEEP, positive end-expiratory pressure; PO2, partial pressure of oxygen; SVR, systemic vascular resistance; TBARS, thiobarbituric acid-reacting substances; TFA, trifluoroacetic acid; TNF-α, tumour necrosis factor-α; VO2, oxygen consumption

SummaryCoagulation abnormalities have been implicated in the pathogenesis of sepsis and organ dysfunction. Nitric oxide (NO) is regarded as a critical mediator of many vascular pathologies, including sepsis. However, limited evidence is available to document a relationship between NO generated by inducible NO synthase (iNOS) and hemostatic abnormalities in sepsis. Therefore, we evaluated the effects of selective iNOS inhibition on markers of endothelial and coagulation homeostasis in a clinically relevant model of porcine bacteremia induced and maintained for 24 hours (h) with a continuous infusion of live P. aeruginosa. After 12 h of sepsis, animals received either vehicle (Control, n = 7) or continuous infusion of selective iNOS inhibitor L-NIL (n=7). Before as well as 12, 18 and 24 h after starting P. aeruginosafollowing variables related to i) endothelial dysfunction (von Willebrand factor [vWf]; tissue plasminogen activator activity [t-PA]; ii) coagulation (thrombin-antithrombin complexes [TAT]; platelet count); iii) fibrinolysis (t-PA activity, activity of plasminogen activator inhibitor type 1 (PAI-1 act); and iv) oxidative/ nitrosative stress (isoprostanes, nitrate/nitrite levels) were measured. L-NIL inhibited sepsis-induced increase in plasma nitrate/nitrite and isoprostanes concentrations, prevented hypotension and acidosis. L-NIL significantly attenuated sepsisinduced rise in plasma vWF and TAT. P. aeruginosa-induced drop in t-PA activity was blunted by iNOS inhibition, while increased PAI-1 and reduced platelet count were not reversed by the treatment. In conclusion, selective iNOS inhibition was associated with attenuation of sepsis-induced coagulation and endothelial dysfunction suggesting the interplay between mediators of vascular system and hemostatic balance. Reduction of oxidative stress probably contributes to the beneficial effects afforded by iNOS blockade.

Nitric Oxide (NO) plays a controversial role in the pathophysiology of sepsis and septic shock. Its vasodilatory effects are well known, but it also has pro- and antiinflammatory properties, assumes crucial importance in antimicrobial host defense, may act as an oxidant as well as an antioxidant, and is said to be a "vital poison" for the immune and inflammatory network. Large amounts of NO and peroxynitrite are responsible for hypotension, vasoplegia, cellular suffocation, apoptosis, lactic acidosis, and ultimately multiorgan failure. Therefore, NO synthase (NOS) inhibitors were developed to reverse the deleterious effects of NO. Studies using these compounds have not met with uniform success however, and a trial using the nonselective NOS inhibitor N(G)-methyl-l-arginine hydrochloride was terminated prematurely because of increased mortality in the treatment arm despite improved shock resolution. Thus, the issue of NOS inhibition in sepsis remains a matter of debate. Several publications have emphasized the differences concerning clinical applicability of data obtained from unresuscitated, hypodynamic rodent models using a pretreatment approach versus resuscitated, hyperdynamic models in high-order species using posttreatment approaches. Therefore, the present review focuses on clinically relevant large-animal studies of endotoxin or living bacteria-induced, hyperdynamic models of sepsis that integrate standard day-to-day care resuscitative measures.

Pretreatment with tempol, a membrane-permeable radical scavenger, has been shown to be protective in rodent models of endotoxic and Gram-positive shock. However, neither the pretreatment design nor hypodynamic endotoxic shock in rodents mimics the clinical scenario. Therefore, we investigated the effects of tempol in a posttreatment model of long-term, volume-resuscitated, hyperdynamic porcine bacteremia.Prospective, randomized, controlled experimental study.University animal laboratory.Sixteen anesthetized, mechanically ventilated, and instrumented pigs.Sepsis was induced and maintained for 24 hrs with continuous infusion of live Pseudomonas aeruginosa. After 12 hrs of hyperdynamic sepsis, animals were randomized to receive either vehicle (control, n = 8) or continuous infusion of tempol (n = 8, 30 mg/kg/hr).Systemic and hepatosplanchnic hemodynamics, oxygen exchange, metabolism, ileal mucosal microcirculation, and tonometry as well as oxidative stress and coagulation variables were assessed before and after 12, 18, and 24 hrs of P. aeruginosa infusion. Tempol significantly attenuated reduction in mean arterial pressure. Despite comparable mesenteric macrocirculation, tempol attenuated the otherwise progressive deterioration in ileal mucosal microcirculation and prevented mucosal acidosis. By contrast, treatment with tempol failed to influence the P. aeruginosa-induced derangements of hepatosplanchnic redox state, liver lactate clearance, and regional acidosis but prevented the development of renal dysfunction. In addition, tempol reduced nitrosative stress without significant effect on the gradual increase in plasma 8-isoprostanes. Finally, tempol attenuated sepsis-induced endothelial (von Willebrand factor) and hemostatic dysfunction (thrombin-antithrombin complexes, plasminogen activator inhibitor-type 1).The radical scavenger tempol partially prevented live bacteria from causing key features of hemodynamic and metabolic derangements in porcine hyperdynamic sepsis and beneficially affected surrogate markers of sepsis-induced endothelial and coagulation dysfunction. Incomplete reduction of oxidative stress because of dilutional effects and/or missed optimal therapeutic window for antioxidant treatment when used in posttreatment approach may account for the only partial protection by tempol in this model.

To evaluate the effects of post-pyloric enteral nutrition (EN) on hepato-splanchnic and systemic hemodynamics, metabolism and gastric mucosal energy balance in septic patients.Prospective clinical study.Medical intensive care unit (ICU) in a university hospital.Ten hemodynamically stable, mechanically ventilated patients with severe sepsis. Eight patients required norepinephrine.Low dose post-pyloric EN (Survimed, 40 ml bolus, 40 ml h(-1) continuously).Three data sets: F1 = baseline fasting, EN(120) = after 120 min of EN, F2=120 min after EN cessation. In addition to global hemodynamics and gastric mucosal PCO(2), we measured hepato-splanchnic blood flow (HSBF) using continuous primed indocyanine green dye infusion with hepatic venous sampling. The mean arterial pressure remained unchanged. During EN systemic vascular resistance decreased ( p0.05), while cardiac index increased (p0.001). Simultaneously, HSBF increased during EN and decreased again at F2 (1.54 [0.88; 1.66] l min(-1) m(-2 )at F1; 1.72 [1.18; 1.83] l min(-1) m(-2 )at EN and 1.38 [0.91; 1.63] l min(-1) m-(2 )at F2, p0.001). Hepatic venous acid base status, lactate/pyruvate ratio and splanchnic lactate balance remained unchanged. There was also no change in splanchnic oxygen extraction ratio or in gastric mucosal to arterial PCO(2) difference.The initiation of low dose post-pyloric EN in medical ICU patients with severe sepsis led to the parallel increase of systemic and hepato-splanchnic blood flow. Hepato-splanchnic energy metabolism, oxygen kinetics and gastric mucosal energy balance did not deteriorate during EN, suggesting that EN during sepsis may not be harmful even in patients requiring norepinephrine.

Purpose. To investigate the pattern of changes of gut mucosal, glomerular, and pulmonary permeability in response to major resectional intestinal surgery, and to evaluate whether these changes are related to oxidative stress. Methods. Eight patients undergoing elective intestinal surgery. Lactulose/mannitol ratio (LMR), urinary albumin/creatinine ratio (MACR), and extravascular lung water and its ratio to intrathoracic blood volume (EVLW/ITBV) were measured preoperatively and at different time points postsurgery. The oxidant/antioxidant balance was assessed by measuring thiobarbituric acid-reactive species, reduced glutathione, plasma total antioxidant capacity, superoxide dismutase, and glutathione peroxidase. Results. Uncomplicated intestinal surgery was associated with early increase in LMR and MACR. The EVLW/ITBV ratio increased, but still remained within the normal range. The amount of EVLW was not affected. While renal permeability changes resolved rapidly, increased intestinal permeability persisted longer postoperatively. There was no evidence for any marked disturbances in the oxidant/antioxidant balance. Conclusions. This pilot study indicated that a moderate increase in gut and renal permeability, even in the absence of clinical sequelae, is an early feature of uncomplicated intestinal surgical trauma. These alterations are not accompanied by any clinically detectable changes in pulmonary permeability.

Background: This study evaluated the effects of protocol-guided fluid loading on extravascular lung water (EVLW) and hemodynamics in a group of patients at high risk for volume expansion-induced pulmonary and systemic edema. Methods: Nine acutely admitted septic patients with acute lung injury (ALI) were prospectively studied. In addition to sepsis and ALI, the following criteria indicating increased risk for edema formation had to be fulfilled: increased vascular permeability defined as microalbuminuria greater than fivefold normal and hypoalbuminemia

Introduction: Insulin pump therapy presents an increasingly used method. Its usage has been steadily increasing within last 40 years and number of studies concerning the insulin pump therapy commencement and various aspects arising in course of the treatment, was presented. But only few studies dealing with the patients after insulin pump treatment termination exist. Furthermore, the majority of these studies are focused on pediatric population. Objectives: to determine, whether the glycemic control changes after insulin pump termination regardless of the type of diabetes or method of treatment withdrawn (pump withdrawn by a physician vs. patient’s wish). To evaluate whether the glycemic control after insulin pump termination differs in type 1 and type 2 diabetic patients and if there are any changes after insulin pump termination due to the method of treatment withdrawn (pump withdrawn by a physician vs. patient’s wish). Methods: The CSII treatment was terminated to a total of 228 patients in 2001 - 2012. 74 patients had sufficient data to analyze four variables: HbA1c, weight, total daily bolus insulin dose, and total daily basal insulin dose. The initial values was derived from data 3-6 months before the treatment withdrawal, other data were collected at time of withdrawal, and at 3, 6, 12 and 24 months following the CSII treatment termination. Total length of follow-up was 2.5 years. Results: There was no significant change in HbA1c: it was 78.5 mmol/mol (interquartil range 69; 95) at time of insulin pump treatment (specifically in the last half year prior to treatment withdrawal) and 81 mmol/mol (68; 93) at time of treatment termination (p=0,365). The median of weight was 81 kg (interquartil range 67; 95) 3-6 months prior to treatment termination and 80 kg (interquartil range 66,8; 97) at time of withdrawal. These changes are also nonsignificant (p=0,963). The only significant change observed was the increase in the total daily bolus insulin dose after the treatment termination - median at time of termination 20 IU/day and after withdrawal 30 IU/day (p=0,001). The dose of basal insulin was not significant (p=0,619). The evaluation of subgroups (type 1 diabetes versus type 2 diabetes and pump withdrawn by a physician versus patient’s wish group) was the same results - e.g. the only significant change was in the dose of bolus insulin. Conclusions: In our study, we were not able to demonstrate any impact of insulin pump treatment termination on the further development of glycemic control of the patients.

Emerging evidence has linked mitochondrial dysfunction to the pathogenesis of many renal disorders, including acute kidney injury, sepsis and even chronic kidney disease. Proteomics is a powerful tool in elucidating the role of mitochondria in renal pathologies. Since the pig is increasingly recognized as a major mammalian model for translational research, the lack of physiological proteome data of large mammals prompted us to examine renal mitochondrial proteome in porcine kidney cortex and medulla Kidneys were obtained from six healthy pigs. Mitochondria from cortex and medulla were isolated using differential centrifugation and proteome maps of cortical and medullar mitochondria were constructed using two-dimensional gel electrophoresis (2DE). Protein spots with significant difference between mitochondrial fraction of renal cortex and medulla were identified by mass spectrometry. Proteomic analysis identified 81 protein spots. Of these spots, 41 mitochondrial proteins were statistically different between renal cortex and medulla (p

Objective: To compare the effects of a 12 h continuous infusion of iloprost, a stable prostacyclin analogue, on hepatic blood flow (Qliv), O2 exchange, and energy metabolism during a 24 h hyperdynamic, porcine endotoxemia with volume resuscitation alone. Design: Prospective, randomized, experimental study with repeated measures. Setting: Investigational animal laboratory. Subjects: Twenty-eight domestic pigs: 16 animals during endotoxemia with volume resuscitation alone (ETX), 12 with endotoxemia, volume resuscitation, and treatment with iloprost (ILO). Interventions: Endotoxemia was initiated by continuous infusion of E. coli lipopolysaccharide. Animals were resuscitated with hetastarch, aimed at maintaining a MAP of >60 mmHg. After 12 h of endotoxemia, iloprost was administered for 12 h in the treatment group, titrated to avoid pharmacologically induced hypotension (MAP

Background In un-resuscitated rodent models of septic shock, the peroxisome proliferator-activated receptor-β/δ (PPAR-β/δ) agonist GW0742 improved visceral organ function. Therefore, we tested the hypothesis whether GW0742 would attenuate kidney injury during long-term, resuscitated, porcine polymicrobial septic shock. Methods Six, 12, and 18 h after the induction of fecal peritonitis by inoculation of autologous feces, anesthetized, mechanically ventilated, and instrumented male pigs with pre-existing atherosclerosis resulting from familial hypercholesteremia and atherogenic diet randomly received either vehicle (dimethyl sulfoxide, n = 12) or GW0742 (n = 10). Resuscitation comprised hydroxyethyl starch and norepinephrine infusion titrated to maintain mean arterial pressure at baseline values. Results Despite aggressive fluid resuscitation, fecal peritonitis was associated with arterial hypotension requiring norepinephrine infusion, ultimately resulting in progressive lactic acidosis and acute kidney injury. GW0742 did not beneficially affect any parameter of systemic and regional hemodynamics, gas exchange, metabolism, or organ function. The parameters of inflammation, oxidative and nitrosative stress, and organ injury (post-mortem analysis for histomorphology and markers of apoptosis) were not influenced either. Immunohistochemistry of pre-shock kidney biopsies from a previous study in this swine strain showed markedly lower PPAR-β/δ receptor expression than in healthy animals. Conclusions In swine with pre-existing atherosclerosis, the PPAR-β/δ agonist GW0742 failed to attenuate septic shock-induced circulatory failure and kidney dysfunction, most likely due to reduced receptor expression coinciding with cardiovascular and metabolic co-morbidity.

Selective incircuit blood cooling could be an effective anticoagulation strategy during hemodialysis. However, it is currently unknown what blood temperature would ensure sufficient anticoagulation. Similarly, no information exists about potential interindividual variability in response to graded hypothermia. Therefore, the aim of this study was to analyze effects of profound hypothermia on human coagulation. Furthermore, a mathematical relationship between blood temperatures and coagulation was sought to predict individual responses to blood cooling. It was designed as a laboratory study. Thromboelastography (TEG) measurements were taken at a temperature range of 38-12°C. To enable measurements below 20°C, the TEG device was placed into an air conditioned chamber allowing for setting of the temperatures over a wide range. The data were analyzed by regression analysis for pooled and individual measurements. Decreasing temperatures always led to a progressive reduction in blood coagulation by delaying the initiation of thrombus formation, as well as by decreasing the speed of its creation and growth. However, the response to cooling was not uniform and the interindividual variability exists. The relationship between blood temperature and coagulation is not linear but exponential (parameters R and K) and sigmoid (parameter α-angle). The lower the blood temperature, the more significant effect on blood coagulation decline. To predict an individual response of the coagulation system over a wide range of temperatures, a mathematical modeling can be used.

Neutrophil and platelet activation and their interactions with endothelial cells are considered central features of sepsis-induced microcirculatory alterations. However, no study has evaluated the microvascular pattern of septic shock patients with chemotherapy-induced severe cytopenia.Demographic and hemodynamic variables together with sublingual microcirculation recording [orthogonal polarization spectral imaging enhanced by sidestream dark-field technology (OPS-SDF) videomicroscopy] were collected in four groups of subjects: septic shock (SS, N = 9), septic shock in cytopenic patients (NSS, N = 8), cytopenia without infection (NEUTR, N = 7), and healthy controls (CTRL, N = 13). Except for controls, all measurements were repeated after complete resolution of septic shock and/or neutropenia. Video files were processed using appropriate software tool and semiquantitatively evaluated [total vascular density (TVD, mm/mm(2)), perfused vessel density (PVD, mm/mm(2)), proportion of perfused vessels (PPV, %), mean flow index (MFI), and flow heterogeneity index (FHI)].Compared with controls, there were statistically significant microcirculatory alterations within all tested groups of patients (TVD: SS = 8.8, NSS = 8.8, NEUTR = 9.1 versus CTRL = 12.6, p0.001; PVD: SS = 6.3, NSS = 6.1, NEUTR = 6.9 versus CTRL = 12.5, p0.001; PPV: SS = 71.6, NSS = 68.9, NEUTR = 73.3 versus CTRL = 98.7, p0.001; MFI: SS = 2.1, NSS = 1.9, NEUTR = 2.1 versus CTRL = 3.0, p0.05; FHI: SS = 1.0, NSS = 0.9, NEUTR = 0.6 versus CTRL = 0.0, p0.001). No significant differences were detected between SS, NSS, and NEUTR groups at baseline. Incomplete restoration of microcirculatory perfusion was observed after septic shock and/or neutropenia resolution with a trend towards better recovery in MFI and FHI variables in NSS as compared with SS patients.Microvascular derangements in septic shock did not differ between noncytopenic and cytopenic patients. Our data might suggest that profound neutropenia and thrombocytopenia do not render microcirculation more resistant to sepsis-induced microvascular alterations. The role and mechanisms of microvascular alterations associated with chemotherapy-induced cytopenia warrant further investigation.

Sepsis has been defined as the systemic host response to infection with an overwhelming systemic production of cytokines leading to generalized endothelial and epithelial damages, to the changes in immune and neuroendocrine systems and consequently to (multiple) organ dysfunction. The myocardial contractile performance is significantly impaired in severe sepsis and septic shock. In this review the major cytokines involved in the development of sepsis are characterized with special emphasis on cardiac function and on regulation of cardiac calcium current.

Sepsis is the most common cause of acute kidney injury (AKI). There has been a growing body of evidence demonstrating the association between worsening of kidney function during sepsis and the risk of short- and long-term mortality. AKI in sepsis is associated with poor outcome and independently predicts increased mortality. Sepsis-associated AKI may therefore serve as a biomarker of adverse physiological events that portends worse outcome. Conversely, the important role of sepsis among intensive care unit patients with nonseptic AKI is increasingly being recognized. Indeed, sepsis represents a significant contributing factor to the overall mortality and incomplete recovery of kidney function in subjects who developed nonseptic AKI. Because AKI portends such an ominous prognosis in sepsis and vice versa, there has been a surge of interest in elucidating mechanisms underlying the complex and bidirectional nature of the interconnections between AKI, sepsis and multiorgan dysfunction. Accumulating data indicate that AKI can trigger several immune, metabolic and humoral pathways, thus potentially contributing to distant organ dysfunction and overall morbidity and mortality. The expanding population of patients with sepsis and AKI, and the associated excess mortality provide a strong basis for further research aimed at addressing more rigorously all potentially modifiable factors to reduce this burden to patients and health care systems. Better insights into bidirectional and synergistic pathways linking sepsis and AKI might open the window for new therapeutic approaches that interrupt this vicious circle. Here, we discuss the rationale for and the current understanding of the bidirectional relationship between AKI and sepsis.

International audience

International audience; The current practice of mechanical ventilation comprises the use of the least inspiratory O2 fraction associated with an arterial O2 tension of 55 to 80 mm Hg or an arterial hemoglobin O2 saturation of 88% to 95%. Early goal-directed therapy for septic shock, however, attempts to balance O2 delivery and demand by optimizing cardiac function and hemoglobin concentration, without making use of hyperoxia. Clearly, it has been well-established for more than a century that long-term exposure to pure O2 results in pulmonary and, under hyperbaric conditions, central nervous O2 toxicity. Nevertheless, several arguments support the use of ventilation with 100% O2 as a supportive measure during the first 12 to 24 hrs of septic shock. In contrast to patients without lung disease undergoing anesthesia, ventilation with 100% O2 does not worsen intrapulmonary shunt under conditions of hyperinflammation, particularly when low tidal volume-high positive end-expiratory pressure ventilation is used. In healthy volunteers and experimental animals, exposure to hyperoxia may cause pulmonary inflammation, enhanced oxidative stress, and tissue apoptosis. This, however, requires long-term exposure or injurious tidal volumes. In contrast, within the timeframe of a perioperative administration, direct O2 toxicity only plays a negligible role. Pure O2 ventilation induces peripheral vasoconstriction and thus may counteract shock-induced hypotension and reduce vasopressor requirements. Furthermore, in experimental animals, a redistribution of cardiac output toward the kidney and the hepato-splanchnic organs was observed. Hyperoxia not only reverses the anesthesia-related impairment of the host defense but also is an antibiotic. In fact, perioperative hyperoxia significantly reduced wound infections, and this effect was directly related to the tissue O2 tension. Therefore, we advocate mechanical ventilation with 100% O2 during the first 12 to 24 hrs of septic shock. However, controlled clinical trials are mandatory to test the safety and efficacy of this approach.

To hypothesize that reduced L-type calcium current with consequent shortening of cardiac repolarization is present in a clinically relevant porcine model of hyperdynamic septic shock. Myocardial depression is a well-recognized manifestation of sepsis and septic shock. Reduction of L-type calcium current was demonstrated to contribute to the myocardial depression in endotoxemic rodents.Laboratory animal experiments.Animal research laboratory at a university.Twenty-two domestic pigs of either gender.In anesthetized, mechanically ventilated, and instrumented pigs, sepsis was induced by bacteremia (central venous infusion of live Pseudomonas aeruginosa) and continued for 22 hrs.Electrocardiogram was recorded before and 22 hrs after induction of bacteremia. RR, QT, and QTc intervals were significantly shortened by sepsis. In vitro, action potentials were recorded in right ventricular trabeculae. Action potential durations were shortened in septic preparations. Tumor necrosis factor-alpha did not influence action potential durations. L-type calcium current was measured in isolated ventricular myocytes. Peak L-type calcium current density was reduced in myocytes from septic animals (8.3 +/- 0.4 pA/pF vs. 11.2 +/- 0.6 pA/pF in control). The voltage dependence of both L-type calcium current activation and inactivation was shifted to more negative potentials in myocytes from septic animals. Action potential-clamp experiments revealed that the contribution of L-type calcium current to the septic action potential was significantly diminished. In cardiac myocytes incubated with tumor necrosis factor-alpha, L-type calcium current was not further affected.In a clinically relevant porcine model, hyperdynamic septic shock induced shortening of ventricular repolarization and reduction of L-type calcium current. The contribution of L-type calcium current to the action potential in septic ventricular myocytes was significantly diminished. Tumor necrosis factor-alpha probably did not contribute to this effect.

There is increasing evidence that the microcirculation and its regulation are severely compromised during many pathological conditions, such as hemorrhage, sepsis, or trauma. The effects of anesthetic agents on macrohemodynamics were investigated intensively in the last several decades. Research regarding modern anesthetics and anesthesia techniques has increased knowledge regarding the nonanesthetic effects of anesthetic agents, including those on organ perfusion and the microcirculation. Alterations in microvascular reactivity, nitric oxide pathways, and cytokine release are presumably the main mechanisms of anesthetic-induced tissue perfusion changes. This review summarizes current methods of microcirculatory status assessment and current knowledge regarding the microcirculatory effects of intravenous and potent volatile anesthetics and anesthesia-related techniques under both normal and pathophysiological conditions.

The aim was to investigate effects of continuous hemofiltration (CHF) and of coupled plasma filtration adsorption (CPFA) on electrophysiological properties of the septic heart. Sepsis was induced in anesthetized pigs by fecal peritonitis and continued for 22 h either without intervention (control sepsis) or with intervention (CHF or CPFA) applied for the last 10 h of this period. Electrocardiograms were recorded at baseline, before induction of peritonitis, and 22 h later, at the end of in vivo experiment. In vitro, action potentials were recorded in right ventricular trabeculae. RR, QT, and QTc (QT corrected for heart rate) intervals were shortened by sepsis. Action potential durations (APDs) were shortened by CHF, but not by CPFA, compared with control sepsis. Continuous hemofiltration prolonged APD. Coupled plasma filtration adsorption filtrate did not exert any effect on APD. Plasma separated during CPFA prolonged APD. Continuous hemofiltration shortened cardiac repolarization, and this effect was reversed by the hemofiltrate. In contrast, neither CPFA nor the CPFA filtrate influenced APD. The data indicate that some inflammatory mediators able to delay cardiac repolarization were removed from plasma to hemofiltrate by CHF but not by CPFA.

Objective Sepsis has been defined as the systemic host response to infection with an overwhelming systemic production of both proinflammatory and anti-inflammatory mediators. Continuous hemofiltration has been suggested as possible therapeutic option that may remove the inflammatory mediators. However, hemodialysis and hemofiltration were reported to influence cardiac electrophysiologic parameters and to increase the arrhythmogenic risk. We hypothesize that sepsis affects electrophysiologic properties of the pig heart and that the effects of sepsis are modified by hemofiltration. Design Laboratory animal experiments. Setting Animal research laboratory at university medical school. Subjects Forty domestic pigs of either gender. Interventions In anesthetized, mechanically ventilated, and instrumented pigs sepsis was induced by fecal peritonitis and continued for 22 hours. Conventional or high-volume hemofiltration was applied for the last 10 hours of this period. Measurements and main results Electrocardiogram was recorded before and 22 hours after induction of peritonitis. RR, QT, and QTc intervals were significantly shortened by sepsis. The plasma levels of interleukin-6 and tumor necrosis factor-alpha were increased in sepsis. High-volume hemofiltration blunted the sepsis-induced increase in tumor necrosis factor-alpha. Action potentials were recorded in isolated ventricular tissues obtained at the end of in vivo experiments. Action potential durations were significantly shortened in septic preparations at all stimulation cycle lengths tested. Both conventional and high-volume hemofiltrations lead to further shortening of action potential durations measured afterward in vitro. This action potential duration shortening was reversed by septic hemofiltrates obtained previously by conventional or high-volume hemofiltration. Tumor necrosis factor-alpha (500 ng/L) had no effect on action potential durations in vitro. Conclusions In a clinically relevant porcine model of hyperdynamic septic shock, both sepsis and continuous hemofiltration shortened duration of cardiac repolarization. The continuous hemofiltration was not associated with an increased prevalence of ventricular arrhythmias. Tumor necrosis factor-alpha or interleukin-6 did not contribute to the observed changes in action potential durations.

The coupled plasma filtration adsorption (CPFA) was developed as an adsorptive hemopurification method aimed at nonselective removal of circulating soluble mediators potentially involved in the pathogenesis of sepsis. We hypothesized that this nonselective hemopurification could protect from detrimental consequences of long-term, volume-resuscitated porcine septic shock. In 16 anesthetized, mechanically ventilated, and instrumented pigs, the hyperdynamic septic shock secondary to peritonitis was induced by intraperitoneally inoculating feces and maintained for 22 h with fluid resuscitation and norepinephrine infusion as needed to maintain MAP above 65 mmHg. After 12 h of peritonitis, animals were randomized to receive either supportive treatment (control, n = 8) or CPFA treatment (CPFA, n = 8). Systemic, hepatosplanchnic, and renal hemodynamics; oxygen exchange; energy metabolism (lactate/pyruvate and ketone body ratios); ileal mucosal and renal cortex microcirculation; systemic inflammation (TNF-alpha, IL-6); nitrosative/oxidative stress (thiobarbituric acid reactive species, nitrates + nitrites); and endothelial/coagulation dysfunction (asymmetric dimethylarginine, von Willebrand factor, thrombin-antithrombin complexes, platelet count) were assessed before and 12, 18, and 22 h of peritonitis. Coupled plasma filtration adsorption neither delayed the development of hypotension nor reduced the dose of norepinephrine. The treatment failed to attenuate sepsis-induced alterations in microcirculation, surrogate markers of cellular energetics, endothelial injury, and systemic inflammation. Similarly, CPFA did not protect from lung and liver dysfunction and even aggravated sepsis-induced disturbances in coagulation and oxidative/nitrosative stress. In this porcine model of septic shock, the early treatment with CPFA was not capable of reversing the sepsis-induced disturbances in various biological pathways and organ systems. Both the efficacy and safety of this method require further rigorous experimental validation in clinically relevant models.

The role of haemofiltration as an adjunctive treatment of sepsis remains a contentious issue. To address the role of dose and to explore the biological effects of haemofiltration we compared the effects of standard and high-volume haemofiltration (HVHF) in a peritonitis-induced model of porcine septic shock. Randomized, controlled experimental study. Twenty-one anesthetized and mechanically ventilated pigs. After 12 h of hyperdynamic peritonitis, animals were randomized to receive either supportive treatment (Control, n = 7) or standard haemofiltration (HF 35 ml/kg per h, n = 7) or HVHF (100 ml/kg per hour, n = 7). Systemic and hepatosplanchnic haemodynamics, oxygen exchange, energy metabolism (lactate/pyruvate, ketone body ratios), ileal and renal cortex microcirculation and systemic inflammation (TNF-α, IL-6), nitrosative/oxidative stress (TBARS, nitrates, GSH/GSSG) and endothelial/coagulation dysfunction (von Willebrand factor, asymmetric dimethylarginine, platelet count) were assessed before, 12, 18, and 22 h of peritonitis. Although fewer haemofiltration-treated animals required noradrenaline support (86, 43 and 29% animals in the control, HF and HVHF groups, respectively), neither of haemofiltration doses reversed hyperdynamic circulation, lung dysfunction and ameliorated alterations in gut and kidney microvascular perfusion. Both HF and HVHF failed to attenuate sepsis-induced alterations in surrogate markers of cellular energetics, nitrosative/oxidative stress, endothelial injury or systemic inflammation. In this porcine model of septic shock early HVHF proved superior in preventing the development of septic hypotension. However, neither of haemofiltration doses was capable of reversing the progressive disturbances in microvascular, metabolic, endothelial and lung function, at least within the timeframe of the study and severity of the model.

Objective: Early goal-directed therapy aims at balancing tissue oxygen delivery and demand. Hyperoxia (i.e., pure oxygen breathing) has not been studied in this context, since sepsis increases oxygen radical production, which is believed to be directly related to the oxygen tension. On the other hand, oxygen breathing improved survival in various shock models. Therefore, we hypothesized that hyperoxia may be beneficial during early septic shock. Design: Laboratory animal experiments. Setting: Animal research laboratory at university medical school. Subjects: Twenty domestic pigs of either gender. Interventions: After induction of fecal peritonitis, anesthetized and instrumented pigs were ventilated with either 100% oxygen or supplemental oxygen as needed to maintain arterial hemoglobin oxygen saturation ≥90%. Normotensive and hyperdynamic hemodynamics were achieved using hydroxyethyl starch and norepinephrine infusion. Measurements and Main Results: Before and at 12,18, and 24 hrs of peritonitis, we measured lung compliance; systemic, pulmonary, and hepatosplanchnic hemodynamics; gas exchange; acid-base status; blood isoprostanes; nitrates; DNA strand breaks; and organ function. Gluconeogenesis and glucose oxidation were calculated from blood isotope and expiratory 13 CO 2 enrichments during continuous intravenous 1,2,3,4,5,6- 13 C 6 -glucose. Apoptosis in lung and liver was assessed postmortem (TUNEL staining). Hyperoxia did not affect lung mechanics or gas exchange but redistributed cardiac output to the hepatosplanchnic region, attenuated regional venous metabolic acidosis, increased glucose oxidation, improved renal function, and markedly reduced the apoptotic death rate in liver and lung. Conclusions: During early hyperdynamic porcine septic shock, 100% oxygen improved organ function and attenuated tissue apoptosis without affecting lung function and oxidative or nitrosative stress. Therefore, it might be considered as an additional measure in the first phase of early goal-directed therapy.

Until now, catecholamines were the drugs of choice to treat hypotension during shock states. Catecholamines, however, also have marked metabolic effects, particularly on glucose metabolism, and the degree of this metabolic response is directly related to the beta2-adrenoceptor activity of the individual compound used. Under physiologic conditions, infusing catecholamine is associated with enhanced rates of aerobic glycolysis (resulting in adenosine triphosphate production), glucose release (both from glycogenolysis and gluconeogenesis), and inhibition of insulin-mediated glycogenesis. Consequently, hyperglycemia and hyperlactatemia are the hallmarks of this metabolic response. Under pathophysiologic conditions, the metabolic effects of catecholamines are less predictable because of changes in receptor affinity and density and in drug kinetics and the metabolic capacity of the major gluconeogenic organs, both resulting from the disease per se and the ongoing treatment. It is also well-established that shock states are characterized by a hypermetabolic condition with insulin resistance and increased oxygen demands, which coincide with both compromised tissue microcirculatory perfusion and mitochondrial dysfunction. This, in turn, causes impaired glucose utilization and may lead to inadequate glucose supply and, ultimately, metabolic failure. Based on the landmark studies on intensive insulin use, a crucial role is currently attributed to glucose homeostasis. This article reviews the effects of the various catecholamines on glucose utilization, both under physiologic conditions, as well as during shock states. Because, to date (to our knowledge), no patient data are available, results from relevant animal experiments are discussed. In addition, potential strategies are outlined to influence the catecholamine-induced effects on glucose homeostasis.

Complex interactions of nitric oxide and other free radicals have been implicated in the pathogenesis of sepsis and organ dysfunction. We hypothesized that simultaneous inducible nitric oxide synthase inhibition (L-N6-[1-iminoethyl]-lysine [L-NIL]) and neutralization of superoxide (O2-) (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl [Tempol]) would protect from detrimental consequences of long-term, volume-resuscitated, hyperdynamic porcine bacteremia. In this prospective, randomized, controlled experimental study, 16 anesthetized, mechanically ventilated and instrumented pigs were exposed to 24 h of continuous infusion of live Pseudomonas aeruginosa. After 12 h of hyperdynamic sepsis, animals were randomized to receive either vehicle (control, n = 8) or combination of L-NIL and Tempol (n = 8). Systemic and hepatosplanchnic hemodynamics, oxygen exchange, metabolism, ileal mucosal microcirculation and tonometry, oxidative stress and coagulation parameters were assessed before, 12, 18, and 24 h of P. aeruginosa infusion. Combined treatment inhibited sepsis-induced increase in plasma nitrate/nitrite, 8-isoprostane, and thiobarbituric acid reactive species concentrations, prevented hypotension, and reversed hyperdynamic circulation. Despite lower intestinal macrocirculation, combined regimen attenuated the otherwise progressive deterioration in ileal mucosal microcirculation and prevented mucosal acidosis. Treatment substantially attenuated mesenteric and hepatic venous acidosis, preserved sepsis-induced impairment of hepatosplanchnic redox state, and prevented the development of renal dysfunction. Finally, coinfusion of L-NIL and Tempol largely attenuated the sepsis-induced rise in plasma von Willebrand factor and thrombin-antithrombin complexes. Thus, hemodynamic, microcirculatory, metabolic, renal, and coagulation data indicate that combining inducible inhibition with cell permeable O2(-) radical scavenger afforded significant protection in porcine sepsis, thus suggesting an important interactive role of O2(-) and nitric oxide in mediating organ dysfunction.

International audience; Lactate is a key metabolite that is produced by every cell and oxidized by most of them, provided that they do contain mitochondria. Its metabolism is connected to energetic homeostasis and the cellular redox state. It is well recognized as an indicator of severe outcome in severely ill patients, however, it is not a detrimental factor per se. Conversely, some recent data tend even to indicate a beneficial effect in several metabolic disorders. Although the liver has long been recognized as a key organ in lactate homeostasis, the kidney also plays a major role as a gluconeogenic organ significantly involved in the glucose-lactate cycle. In acute renal failure, sodium lactate is widely used as a buffer in replacement fluids because the anion (lactate - ) is metabolized and the cation (Na + ) remains, leading to decreased water dissociation and proton concentration. The metabolic disorders related to acute renal failure or associated with it, such as liver failure, may affect lactate metabolism, and therefore they are often regarded as limiting factors for the use of lactate-containing fluids in such patients. By investigating endogenous lactate production in severe septic patients with acute renal failure, we found that an acute exogenous load of lactate did not affect the basal endogenous lactate production and metabolism. This indicates that exogenous lactate is well metabolized even in patients suffering from acute renal failure and severe sepsis with a compromised hemodynamic status.

Sepsis may lead to deranged thromboxane-prostacyclin ratio with consecutive organ dysfunction. Because of the suggested role of the gut in the pathogenesis of septic shock and multiple organ failure, we investigated the effects of the novel dual thromboxane synthase inhibitor and receptor antagonist DTTX-30 (TRASI) on intestinal tissue perfusion, O2 kinetics, and energy metabolism over 24 h of hyperdynamic, normotensive porcine endotoxemia. Before, 12, 18, and 24 h after starting continuous i.v. endotoxin (LPS), we measured portal venous (PV) blood flow, intestinal oxygen extraction (iO2ER), intracapillary hemoglobin O2 saturation (HbO2%) of the ileal wall, intramucosal ileal PCO2, PV lactate-pyruvate (L-P) ratio, and plasma levels of thromboxane and prostacyclin. Treatment with TRASI (0.12 mg/kg i.v. bolus injection followed by an infusion of 0.29 mg/kg/h) initiated after 12 h of LPS infusion markedly reduced the plasma thromboxane levels and attenuated the LPS-induced fall in systemic vascular resistance, resulting in hemodynamic stabilization. TRASI did not influence the LPS-induced increase in PV blood flow nor intracapillary HbO2%, thus reflecting unchanged microcirculatory O2 availability and decreased iO2ER, possibly because of reduced O2 requirements. Nevertheless, TRASI prevented the LPS-induced increase in the PV L-P ratio, attenuated the progression of the ileal mucosal-arterial PCO2 gap, and tended to attenuate the gradual fall of PV pH. Hence, compounds like TRASI may beneficially influence LPS-related derangements of gut energy metabolism.

Our goal was to evaluate the effect of hyperoxia on sublingual and ileostomal microcirculation during hemorrhagic and reperfusion shock in a porcine model simulating the rupture of an abdominal aortic aneurysm (AAA). We wanted to test the effect of hyperoxia on these two vascular beds because hyperoxia is known to cause different arteriolar responses [1].

In almost half of all sepsis patients, acute kidney injury (AKI) develops. However, the pathobiologic differences between sepsis patients with and without AKI are only poorly understood. We used a unique opportunity to examine dynamic inflammatory, renal hemodynamic, and microvascular changes in two clinically relevant large-animal models of sepsis. Our aim was to assess variability in renal responses to sepsis and to identify both hemodynamic and nonhemodynamic mechanisms discriminating individuals with AKI from those in whom AKI did not develop.Thirty-six pigs were anesthetized, mechanically ventilated, and instrumented. After a recovery period, progressive sepsis was induced either by peritonitis (n = 13) or by continuous intravenous infusion of live Pseudomonas aeruginosa (n = 15). Eight sham operated-on animals served as time-matched controls. All animals received standard intensive care unit (ICU) care, including goal-directed hemodynamic management. Before, and at 12, 18, and 22 hours of sepsis, systemic and renal (ultrasound flow probe) hemodynamics, renal cortex microcirculation (laser Doppler), inflammation (interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), oxidative stress (thiobarbituric acid reactive species (TBARS), nitrite/nitrate concentrations (NOx), and renal oxygen kinetics and energy metabolism were measured.In 14 (50%) pigs, AKI developed (62% in peritonitis, 40% in bacteria infusion model). Fecal peritonitis resulted in hyperdynamic circulation, whereas continuous bacteria infusion was associated with normodynamic hemodynamics. Despite insults of equal magnitude, comparable systemic hemodynamic response, and uniform supportive treatment, only those pigs with AKI exhibited a progressive increase in renal vascular resistance. This intrarenal vasoconstriction occurred predominantly in the live-bacteria infusion model. In contrast to AKI-free animals, the development of septic AKI was preceded by early and remarkable inflammatory response (TNF-α, IL-6) and oxidative stress (TBARS).The observed variability in susceptibility to septic AKI in our models replicates that of human disease. Early abnormal host response accompanied by subsequent uncoupling between systemic and renal vascular resistance appear to be major determinants in the early phase of porcine septic AKI. Nonuniform and model-related renal hemodynamic responses that are unpredictable from systemic changes should be taken into consideration when evaluating hemodynamic therapeutic interventions in septic AKI.

Introduction Mechanical ventilation (MV) can injure the lungs and contribute to an overwhelming inflammatory response, leading to acute renal failure (ARF). We previously showed that poly(adenosine diphosphate-ribose) polymerase (PARP) is involved in the development of ventilator-induced lung injury (VILI) and the related ARF, but the mechanisms underneath remain unclear. In the current study we therefore tested the hypothesis that renal blood flow and endothelial, functional and tissue changes in the kidney of rats with lipopolysaccharide (LPS)-induced lung injury aggravated by MV, is caused, in part, by activation of PARP by peroxynitrite. Methods Anesthetized Sprague Dawley rats (n = 31), were subjected to intratracheal instillation of lipopolysaccharide at 10 mg/kg followed by 210 min of mechanical ventilation at either low tidal volume (6 mL/kg) with 5 cm H2O positive end-expiratory pressure or high tidal volume (19 mL/kg) with zero positive end-expiratory pressure in the presence or absence of a peroxynitrite decomposition catalyst, WW85 or a PARP inhibitor, PJ-34. During the experiment, hemodynamics and blood gas variables were monitored. At time (t) t = 0 and t = 180 min, renal blood flow was measured. Blood and urine were collected for creatinine clearance measurement. Arcuate renal arteries were isolated for vasoreactivity experiment and kidneys snap frozen for staining. Results High tidal volume ventilation resulted in lung injury, hypotension, renal hypoperfusion and impaired renal endothelium-dependent vasodilation, associated with renal dysfunction and tissue changes (leukocyte accumulation and increased expression of neutrophil gelatinase-associated lipocalin). Both WW85 and PJ-34 treatments attenuated lung injury, preserved blood pressure, attenuated renal endothelial dysfunction and maintained renal blood flow. In multivariable analysis, renal blood flow improvement was, independently from each other, associated with both maintained blood pressure and endothelium-dependent vasodilation by drug treatment. Finally, drug treatment improved renal function and reduced tissue changes. Conclusions The peroxynitrite-induced PARP activation is involved in renal hypoperfusion, impaired endothelium-dependent vasodilation and resultant dysfunction, and injury, in a model of lung injury.

Continuous renal replacement therapies (CRRT) are widely used for treatment of acute kidney injury in critically ill patients. Little attention has been paid to the potential adverse effects of CRRT related to extracorporeal circuit bioincompatibility. Limited available evidence suggests that intermittent dialysis may compromise hepatosplanchnic perfusion in acute renal failure patients. By contrast, there are no data on the bio(in)compatibility indices in patients treated by CRRT. To investigate this issue, we utilized a long-term porcine model allowing a broad insight into organ hemodynamic, microvascular, metabolic and other pathways not accessible in human medicine.

Introduction Our understanding of septic acute kidney injury (AKI) remains incomplete. A fundamental step is the use of animal models designed to meet the criteria of human sepsis. Therefore, we dynamically assessed renal haemodynamic, microvascular and metabolic responses to, and ultrastructural sequelae of, sepsis in a porcine model of faecal peritonitis-induced progressive hyperdynamic sepsis. Methods In eight anaesthetised and mechanically ventilated pigs, faecal peritonitis was induced by inoculating autologous faeces. Six sham-operated animals served as time-matched controls. Noradrenaline was administered to maintain mean arterial pressure (MAP) greater than or equal to 65 mmHg. Before and at 12, 18 and 22 hours of peritonitis systemic haemodynamics, total renal (ultrasound Doppler) and cortex microvascular (laser Doppler) blood flow, oxygen transport and renal venous pressure, acid base balance and lactate/pyruvate ratios were measured. Postmortem histological analysis of kidney tissue was performed. Results All septic pigs developed hyperdynamic shock with AKI as evidenced by a 30% increase in plasma creatinine levels. Kidney blood flow remained well-preserved and renal vascular resistance did not change either. Renal perfusion pressure significantly decreased in the AKI group as a result of gradually increased renal venous pressure. In parallel with a significant decrease in renal cortex microvascular perfusion, progressive renal venous acidosis and an increase in lactate/pyruvate ratio developed, while renal oxygen consumption remained unchanged. Renal histology revealed only subtle changes without signs of acute tubular necrosis. Conclusion The results of this experimental study argue against the concept of renal vasoconstriction and tubular necrosis as physiological and morphological substrates of early septic AKI. Renal venous congestion might be a hidden and clinically unrecognised contributor to the development of kidney dysfunction.