OBJECTIVES: The use of hemoadsorption (HA) has become popular in the treatment of vasoplegic states associated with massive cytokine release, including septic shock. However, this approach does not seem to be based on robust evidence, and it does not follow international guidelines. To understand the pathophysiological rationale and timing of HA, we conducted a large animal septic shock experiment. DESIGN: Prospective randomized large-animal peritoneal septic shock experiment. SETTING: Laboratory investigation. SUBJECTS: Twenty-six anesthetized, mechanically ventilated, and instrumented pigs randomly assigned into (1) sham-operated group with HA (SHAM, n = 5); (2) sepsis animals without HA (SEPSIS, n = 5); (3) sepsis group with HA at norepinephrine initiation (EARLY, n = 8); and (4) sepsis group with HA initiated at norepinephrine rate reaching 0.5 μg/kg/min (LATE, n = 8). INTERVENTIONS: Peritoneal sepsis was induced by cultivated autologous feces inoculation. A CytoSorb cartridge (200 g) with a blood flow rate of 200 mL/min and heparin anticoagulation was used to perform HA. The animals received sedation and intensive organ support up to 48 h or until they experienced cardiovascular collapse. MEASUREMENTS AND MAIN RESULTS: Systemic hemodynamics, multiple-organ functions, and immune-inflammatory response were measured at predefined periods. The HA treatment was not associated with any measurable benefit in terms of systemic hemodynamics and organ support. The systemic inflammatory markers were unaffected by any of the treatment timings. In contrast, the HA resulted in higher vasopressor load and decreased 36-h survival (5 animals in SHAM (100%), 4 (80%) in SEPSIS, 4 (57%) in EARLY, and 2 (25%) in LATE; p = 0.041). The HA exposure in healthy animals was associated with hemodynamic deterioration, systemic inflammatory response, and cytopenia. CONCLUSIONS: In this large-animal-controlled fulminant sepsis study, the HA was unable to counteract the disease progression in the early or advanced septic shock phase. However, findings from the HA-exposed sham animals suggest potential safety concerns.
- Publikační typ
- časopisecké články MeSH
Infectious diseases, which often result in deadly sepsis or septic shock, represent a major global health problem. For understanding the pathophysiology of sepsis and developing new treatment strategies, reliable and clinically relevant animal models of the disease are necessary. In this review, two large animal (porcine) models of sepsis induced by either peritonitis or bacteremia are introduced and their strong and weak points are discussed in the context of clinical relevance and other animal models of sepsis, with a special focus on cardiovascular and immune systems, experimental design, and monitoring. Especially for testing new therapeutic strategies, the large animal (porcine) models represent a more clinically relevant alternative to small animal models, and the findings obtained in small animal (transgenic) models should be verified in these clinically relevant large animal models before translation to the clinical level.
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Animal models are essential in understanding of the mechanisms of sepsis moreover the development and the assessment of emerging therapies. In clinically relevant porcine model, however, a significant variability in the host response has been observed among animals. Thus, there is a strong demand to better understand the potential sources of this heterogeneity. In this study, we compared faecal microbiome composition of 12 animals. Three samples were collected at different time points from each animal. Bacteriome was subjected to 16S rDNA profiling. A significant difference in bacterial composition was associated with the season (p < 0.001) but not with the sex of the pig (p = 0.28), the timing of sample collection (p = 0.59), or interactions thereof (all p > 0.3). The season batch explained 55% of the total variance in the bacteriome diversity. The season term was highly significant from the high-resolution level of the bacterial amplicon sequencing variants up to the level of phylum. The diversity of the microbiome composition could significantly influence experimental model of sepsis, and studies are warranted to demonstrate the effects of gut microbiome diversity on the host-response. If confirmed, control of the gut microbiome should become a standard part of the pre-clinical sepsis experiments.
Five-sixths nephrectomy is a widely used experimental model of chronic kidney disease (CKD) that is associated with severe mitochondrial dysfunction of the remnant tissue. In this study, we assessed the effect of CKD on mitochondrial respiration separately in the rat kidney cortex and medulla 10 weeks after induction of CKD by subtotal 5/6 nephrectomy (SNX). Mitochondrial oxygen consumption was evaluated on mechanically permeabilized samples of kidney cortex and medulla using high-resolution respirometry and expressed per mg of tissue wet weight or IU citrate synthase (CS) activity. Mitochondrial respiration in the renal cortex of SNX rats was significantly reduced in all measured respiratory states if expressed per unit wet weight and remained lower if recalculated per IU citrate synthase activity, i.e. per mitochondrial mass. In contrast, the profound decrease in the activity of CS in SNX medulla resulted in significantly elevated respiratory states expressing the OXPHOS capacity when Complexes I and II or II only are provided with electrons, LEAK respiration after oligomycin injection, and Complex IV-linked oxygen consumption per unit CS activity suggesting compensatory hypermetabolic state in remaining functional mitochondria that is not sufficient to fully compensate for respiratory deficit expressed per tissue mass. The results document that CKD induced by 5/6 nephrectomy in the rat is likely to cause not only mitochondrial respiratory dysfunction (in the kidney cortex), but also adaptive changes in the medulla that tend to at least partially compensate for mitochondria loss.
- MeSH
- chronická renální insuficience * MeSH
- citrátsynthasa MeSH
- krysa rodu rattus MeSH
- kůra ledviny MeSH
- ledviny * metabolismus MeSH
- mitochondrie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Metabolic syndrome is associated with hypercholesterolemia, cardiac remodeling, and increased susceptibility to ventricular arrhythmias. Effects of diet-induced hypercholesterolemia on susceptibility to torsades de pointes arrhythmias (TdP) together with potential indicators of arrhythmic risk were investigated in three experimental groups of Carlsson's rabbit model: (1) young rabbits (YC, young control, age 12-16 weeks), older rabbits (AC, adult control, age 20-24 weeks), and older age-matched cholesterol-fed rabbits (CH, cholesterol, age 20-24 weeks). TdP was induced by α-adrenergic stimulation by methoxamine and IKr block in 83% of YC rabbits, 18% of AC rabbits, and 21% of CH rabbits. High incidence of TdP was associated with high incidence of single (SEB) and multiple ectopic beats (MEB), but the QTc prolongation and short-term variability (STV) were similar in all three groups. In TdP-susceptible rabbits, STV was significantly higher compared with arrhythmia-free rabbits but not with rabbits with other than TdP arrhythmias (SEB, MEB). Amplitude-aware permutation entropy analysis of baseline ECG could identify arrhythmia-resistant animals with high sensitivity and specificity. The data indicate that the TdP susceptibility in methoxamine-sensitized rabbits is affected by the age of rabbits but probably not by hypercholesterolemia. Entropy analysis could potentially stratify the arrhythmic risk and identify the low-risk individuals.
- Publikační typ
- časopisecké články MeSH
Porcine model of peritonitis-induced sepsis is a well-established clinically relevant model of human disease. Interindividual variability of the response often complicates the interpretation of findings. To better understand the biological basis of the disease variability, the progression of the disease was compared between animals with sepsis and septic shock. Peritonitis was induced by inoculation of autologous feces in fifteen anesthetized, mechanically ventilated and surgically instrumented pigs and continued for 24 h. Cardiovascular and biochemical parameters were collected at baseline (just before peritonitis induction), 12 h, 18 h and 24 h (end of the experiment) after induction of peritonitis. Analysis of multiple parameters revealed the earliest significant differences between sepsis and septic shock groups in the sequential organ failure assessment (SOFA) score, systemic vascular resistance, partial pressure of oxygen in mixed venous blood and body temperature. Other significant functional differences developed later in the course of the disease. The data indicate that SOFA score, hemodynamical parameters and body temperature discriminate early between sepsis and septic shock in a clinically relevant porcine model. Early pronounced alterations of these parameters may herald a progression of the disease toward irreversible septic shock.
- Publikační typ
- časopisecké články MeSH
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.
V posledních letech přitahuje terapeutický přístup s využitím mimotělních hemadsorpčních metod u kriticky nemocných stále větší zájem. Snaha o časný zásah do patofyziologických procesů, které doprovázejí řadu inzultů u pacientů v intenzivní péči, představuje nepochybně atraktivní koncept, v současnosti pronikající do klinické praxe navzdory absenci evidence. Níže uvedený text představuje kritický pohled autorů na současný stav problematiky hemadsorpčních metod a jejich využití u kriticky nemocných, zejména septických pacientů.
Recently, the therapeutic approach using the extracorporeal hemadsorption technologies attracted much attention. Effort to affect the patophysiological processess associated with critical illness represents an attractive concept, that penetrates into clinical practice. Here we present the critical opinion on current status of hemadsorption therapy in critical ill patients in the context of published evidence.
Background: Treatment with mesenchymal stem cells (MSCs) has elicited considerable interest as an adjunctive therapy in sepsis. However, the encouraging effects of experiments with MSC in rodents have not been adequately studied in large-animal models with better relevance to human sepsis. Objectives: Here, we aimed to assess safety and efficacy of bone marrow-derived MSCs in a clinically relevant porcine model of progressive peritonitis-induced sepsis. Methods: Thirty-two anesthetized, mechanically ventilated, and instrumented pigs were randomly assigned into four groups (n = 8 per group): (1) sham-operated group (CONTROL); (2) sham-operated group treated with MSCs (MSC-CONTROL); (3) sepsis group with standard supportive care (SEPSIS); and (4) sepsis group treated with MSCs (MSC-SEPSIS). Peritoneal sepsis was induced by inoculating cultivated autologous feces. MSCs (1 × 106/kg) were administered intravenously at 6 h after sepsis induction. Results: Before, 12, 18, and 24 h after the induction of peritonitis, we measured systemic, regional, and microvascular hemodynamics, multiple-organ functions, mitochondrial energy metabolism, systemic immune-inflammatory response, and oxidative stress. Administration of MSCs in the MSC-CONTROL group did not elicit any measurable acute effects. Treatment of septic animals with MSCs failed to mitigate sepsis-induced hemodynamic alterations or the gradual rise in Sepsis-related organ failure assessment scores. MSCs did not confer any protection against sepsis-mediated cellular myocardial depression and mitochondrial dysfunction. MSCs also failed to modulate the deregulated immune-inflammatory response. Conclusion: Intravenous administration of bone marrow-derived MSCs to healthy animals was well-tolerated. However, in this large-animal, clinically relevant peritonitis-induced sepsis model, MSCs were not capable of reversing any of the sepsis-induced disturbances in multiple biological, organ, and cellular systems.
Increased activity of the sympathetic nervous system (SNS) has been proposed as a risk factor for increased cardiovascular mortality in patients with chronic kidney disease (CKD). Information on the activity of cardiac sympathetic innervation is non-homogeneous and incomplete. The aim of our study was to evaluate the tonic effect of SNS on heart rate, norepinephrine turnover and direct and indirect effects of norepinephrine in left ventricles of subtotally nephrectomized rats (SNX) in comparison with sham-operated animals (SHAM). Renal failure was verified by measuring serum creatinine and urea levels. SNX rats developed increased heart rates and blood pressure (BP). The increase in heart rate was not caused by sympathetic overactivity as the negative chronotropic effect of metipranolol did not differ between the SNX and SHAM animals. The positive inotropic effects of norepinephrine and tyramine on papillary muscle were not significantly different. Norepinephrine turnover was measured after the administration of tyrosine hydroxylase inhibitor, pargyline, tyramine, desipramine, and KCl induced depolarization. The absolute amount of released norepinephrine was comparable in both groups despite a significantly decreased norepinephrine concentration in the cardiac tissue of the SNX rats. We conclude that CKD associated with renal denervation in rats led to adaptive changes characterized by an increased reuptake and intracellular norepinephrine turnover which maintained normal reactivity of the heart to sympathetic stimulation.
- MeSH
- chronická renální insuficience komplikace metabolismus patofyziologie MeSH
- kardiovaskulární nemoci etiologie MeSH
- ledviny metabolismus MeSH
- modely nemocí na zvířatech MeSH
- nefrektomie MeSH
- neuropeptid Y metabolismus MeSH
- noradrenalin krev MeSH
- peptid spojený s genem pro kalcitonin metabolismus MeSH
- potkani Wistar MeSH
- srdeční frekvence MeSH
- srdeční komory metabolismus patofyziologie MeSH
- sympatický nervový systém patofyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
