Early Fluid Resuscitation and High Volume Hemofiltration Decrease Septic Shock Progression in Swine

A model of porcine polymicrobial septic shock

BACKGROUND

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Mortality of patients with sepsis is high and largely unchanged throughout the past decades. Animal models have been widely used for the study of sepsis and septic shock, but translation into effective treatment regimes in the clinic have mostly failed. Pigs are considered as suitable research models for human diseases due to their high comparability and similarity to human anatomy, genetics, and the immune system. We here evaluated the previously reported models of septic shock in pigs and established a novel model of polymicrobial sepsis that meets the clinical criteria of septic shock in pigs.

MATERIALS AND METHODS

The literature search was performed using the keywords "pig", "sepsis" and "septic shock". For the establishment of septic shock in n = 10 German landrace pigs, mechanical ventilation was initiated, central venous and arterial lines and invasive hemodynamic monitoring via pulse contour cardiac output measurement (PiCCO) established. Peritoneal polymicrobial faecal sepsis was induced by application of 3 g/kg body weight faeces into the abdominal cavity. Septic shock was defined according to the third international consensus definitions (Sepsis-3). Upon shock, pigs underwent the 1-h bundle for the treatment of human sepsis. Cytokine levels were measured by ELISA.

RESULTS

Published porcine sepsis models exhibited high methodological variability and did not meet the clinical criteria of septic shock. In our model, septic shock developed after an average of 4.8 ± 0.29 h and was associated with a reproducible drop in blood pressure (mean arterial pressure 54 ± 1 mmHg) and significant hyperlactatemia (3.76 ± 0.65 mmol/L). Septic shock was associated with elevated levels of interleukin-6 (IL6) and initial cardiac depression followed by a hyperdynamic phase with significant loss of systemic vascular resistance index after initial resuscitation. In addition, organ dysfunction (acute kidney injury) occurred.

CONCLUSIONS

We here established a model of septic shock in pigs that meets the clinical criteria of septic shock utilized in human patients. Our model may thus serve as a reference for clinically relevant sepsis research in pigs.

Clinical effects of hemoperfusion combined with pulse high-volume hemofiltration on septic shock

Sepsis can cause septic shock, multiple organ dysfunction and even death. The combination of different blood purification would be the certain trend in the treatment of sepsis.This study was to evaluate the clinical effects of hemoperfusion (HP) combined with pulse high volume hemofiltration (PHVHF) on septic shock.Thirty cases were involved in this study and were randomly divided into two groups: HP and PHVHF group (n = 15) and CVVH (continuous veno-venous hemofiltration) group (n = 15). Acute physiology and chronic health evaluation (APACHE) II scores, sequential organ failure assessment (SOFA) scores as well as biochemical changes were measured before and after the treatment. The levels of IL-6, IL-10, and TNF-α in plasma were assessed by ELISA before and after treatment for 2 and 24 h. The norepinephrine doses were also analyzed. The 28-day mortalities in both groups were also compared.In both groups, body temperature (BT), respiratory rate (RR), white blood cells (WBC), C-reactive protein (CRP), Procalcitonin (PCT), lactic acid, serum creatinine, APACHE II scores and SOFA scores decreased after hemofiltration (P < .05). The HP&PHVHF group was superior to the CVVH group in CRP, APACHE II score (P < .01), and heart rate (HR), WBC, PCT, SOFA (P < .05). The doses of norepinephrine were also decreased after treatment (P < .01), with more reduction in the HP&PHVHF group (P < .05). After 24 h of treatment, the levels of IL-6, IL-10, and TNF-α decreased in both groups (P < .05), and the decrease was more significant in HP&PHVHF group (P < .05). In combined group, after 2 h of hemoperfison, there was a significant reduction in these inflammatory factors (P < .01). Combined therapy group's mortality was 26.7%, while CVVH group's was 40%.HP combined with PHVHF has a significant effect on septic shock and can be an important therapy for septic shock.

Continuous hemodiafiltration as a rescue therapy for patients with cardiopulmonary failure caused by enterovirus-71: a retrospective observational study in a PICU

Background

Hand, foot and mouth disease (HFMD) remains a burdensome health issue in mainland China. Enterovirus71 (EV-A71) is the main pathogen of severe HFMD. Continuous hemofiltration improves fluid overload, restores kidney function and alleviates inflammatory reactions. The aim of the present study was to evaluate the effects of continuous veno-venous hemodiafiltration (CVVHDF) on severe HFMD caused by EV-A71(EV-A71-HFMD) in a pediatric intensive care unit (PICU).

Methods

A retrospective observational study was performed in a tertiary university PICU from January 2012 to December 2016. Children with severe EV-A71-HFMD complicated by cardiopulmonary failure were included. The patients were divided into a CVVHDF group and a conventional therapy (control) group (non-CVVHDF). The demographics, characteristics, and outcomes between the groups were collected and analyzed.

Results

Twenty-nine patients with severe EV-A71-HFMD were enrolled. The 28-day mortality was 17.6% (3/17) in the CVVHDF group and 33.3% (4/12) in the non-CVVHDF group, with no statistical significance between the two groups (P = 0.403). The median interval between CVVHDF initiation and PICU admission was 6 (4,8.5) hrs, and the median duration of CVVHDF was 48 (36, 64) hrs. The left ventricular ejection fraction (LVEF) and cardiac index (CI) in the CVVHDF group were improved after treatment. The plasma levels of catecholamines and renin-angiotensin-aldosterone system (RAAS) substances in the CVVHDF group were significantly decreased after treatment. The decreased catecholamines and RAAS substances included adrenalin (169.8 [145.5, 244.6] vs. 148.0 [109.0, 208.1] ng/L, P = 0.033), dopamine (152.7 [97.0, 191.1] vs. 96.0 [68.0, 160.9] ng/L, P = 0.026), angiotensin II (185.9 [125.2, 800.0] vs. 106.0 [90.8, 232.5] ng/L, P = 0.047), aldosterone (165.7 [94.0, 353.3] vs. 103.3 [84.3, 144.3] ng/L, P = 0.033), and renin (1.12 [0.74, 3.45] vs. 0.79 [0.52, 1.25] μg/L/h, P = 0.029),

Conclusions

CVVHDF reduced the levels of catecholamines and RAAS substances and improved cardiovascular function. Continuous hemodiafiltration may represent a potential therapy in patients with severe EV-A71-HFMD complicated with cardiopulmonary failure.

The Systemic Alterations of Lipids, Alanine-Glucose Cycle and Inter-Organ Amino Acid Metabolism in Swine Model Confirms the Role of Liver in Early Phase of Septic Shock

Septic shock is a medical emergency and is one of the main causes of mortality in critically ill patients. Given the pathophysiological complexity of sepsis spectrum and progression in clinical settings, animal models become essential tools to improve patient care, and to understand key mechanisms that may remain masked from the heterogeneity of clinical practice. Our aim was to verify whether the metabolic constellations we previously reported for septic shock patients appear also in our septic shock swine model as systemic markers of early disturbances in energy metabolism and hepatic homeostasis. Septic shock was induced in anesthetized, instrumented, and ventilated adult swines by polymicrobial peritonitis. Hemodynamic and serial measurements of arterial and mixed venous blood gasses were made. Laboratory measurements and mass spectrometry-based targeted quantitative plasma metabolomics were performed in blood samples collected at baseline, at shock and at fully resuscitation after fluids and vasopressors administration. Data elaboration was performed by multilevel and multivariate analysis. Changes in hemodynamic, blood chemistry, and inflammatory markers were in line with a septic shock phenotype. Time course alteration of systemic metabolites were characterized by marked decreased in phosphatidylcholines and lysophosphatidylcholines species, altered alanine-glucose cycle and inter-organ amino acid metabolism, pointing toward an early hepatic impairment similarly to what we previously reported for septic shock. This is the first study in which an experimental swine model of septic shock recapitulates the main metabolic derangements reported in a clinical setting of shock. These events occur within hours from infections and may act as early metabolic features to assist in evaluating subclinical hepatic alterations and pave the way to improve the management of septic shock.

Oxygen delivery to the blood stream by the dialysis fluid during continuous renal replacement therapy ex vivo

Continuous renal replacement therapy (CRRT) maintains a balance in body water and electrolytes. CRRT supplies a higher quantity of fluid than intravenous fluid therapy along with simultaneous fluid withdrawal. We hypothesized that use of a high-oxygen-containing solution for high-volume fluid exchange would improve oxygenation in the blood during CRRT. To start with, we prepared a solution containing high oxygen. The objective of this study was to determine if this solution would increase the partial pressure of oxygen (pO₂) in the blood more than that using a conventional solution during CRRT. We compared the gas profile of the experimental fluid ex vivo in a simulated CRRT for 24 h, using 2-L batches of bovine blood. A significant increase in the pO₂, pH, and total oxygen delivery, and a significant decrease in the partial pressure of carbon dioxide (pCO₂) were estimated in the bovine blood using the experimental solution during the simulated CRRT. This method is simpler to apply for oxygenation than the conventional method, and will be beneficial to hypoxic patients in terms of improving their blood oxygenation during CRRT.