Effects of continuous high-volume hemofiltration on experimental severe acute pancreatitis in pigs

Early continuous blood purification affects TNF-α, IL-1β, and IL-6 in patients with severe acute pancreatitis via inhibiting TLR4 signaling pathway

To exploit whether early continuous blood purification (CBP) inhibits the Toll-like receptors 4 (TLR4) signaling pathway in the peripheral blood of patients with severe acute pancreatitis (SAP) and whether it affects the abundance of inflammatory factors; 130 SAP patients were randomly selected and divided into Groups B and C. Both groups received conventional treatment. Among them, Group C was given early CBP treatment. Another 60 healthy cases in physical examination at the same time were selected as Group A. The abundances of TLR4 and inflammatory factors were detected before and after treatment. Compared with Group B, (1) the symptoms in Group C improved more markedly; (2) protein contents of TLR4 and nuclear factor kappa B (NF-κB) in Group C diminished more signally; (3) the abundances of tumor necrosis factor alpha (TNF-α), cytokine interleukin-1β (IL-1β), and cytokine interleukin 6 (IL-6) in Group C decreased (p < 0.05); and (4) the abundance of TLR4 in Group C was positively correlated with those of TNF-α, IL-1β, and IL-6 after treatment (all p < 0.001). Early CBP inhibits TLR4 signaling pathway in SAP patients and attenuates the abundance of inflammatory factors to a certain extent, which may provide a new clinical treatment strategy for SAP.

Early fluid resuscitation in severe acute pancreatitis

Acute pancreatitis (AP) is a common clinical emergency disorder, and its morbidity is increasing gradually. Severe AP (SAP) often occurs with a sudden onset and high mortality. Microcirculation disturbance and hemodynamic abnormality is one of the main pathophysiologic mechanisms of SAP. Early fluid resuscitation is the cornerstone of therapy. However, at present, the fluid type, the amount of fluid resuscitation, and the rehydration rate are still in dispute. Early goal-directed fluid therapy as an important individualized liquid resuscitation strategy has great significance to improve the prognosis of SAP. This article reviews the pathophysiological mechanisms of microcirculation disturbance, the related dispute of liquid resuscitation therapy, and the application of early goal-directed treatment strategy.

Evaluation of HVHF for the treatment of severe acute pancreatitis accompanying MODS

Systemic inflammatory response syndrome (SIRS) prevention is key to severe acute pancreatitis (SAP) treatment and the assessment of high-volume hemofiltration (HVHF) for treating SAP accompanying multiple organ dysfunction syndromes.In this prospective controlled study, 40 SAP patients were divided into 2 groups: control (n = 22, treated with fasting, decompression, and intravenous somatostatin) and HVHF (n = 18, HVHF administration in addition to the treatment in the control group) groups; and were assessed for serum and urine amylase, WBC, C-reactive protein (CRP), and hepatic and renal functions. Vital signs and abdominal symptoms were recorded, and complications and mortality were analyzed.APACHE II scores in the HVHF group were significantly lower than in the control group at 3 and 7 days (6.3 ± 1.7 vs 9.2 ± 2.1 and 3.3 ± 0.8 vs 6.2 ± 1.7, respectively). Compared with controls, serum, and urine amylase, WBC, CRP, and organ functions significantly improved after HVHF treatment. Meanwhile, mortality (16.7% vs 31.8%) and complication (11.1% vs 40.9%) rates were significantly reduced.The other clinical parameters were significantly ameliorated by HVHF. HVHF rapidly reduces abdominal symptoms and improves prognosis, reducing mortality in SAP patients; and is likely through systemic inflammatory response syndrome attenuation in the early disease stage.

Generation of blood circulating DNA: the sources, peculiarities of circulation and structure

Extracellular nucleic acids (exNA) were described in blood of both healthy and illness people as early as in 1948, but staied overlooked until middle 60-th. Starting from the beginning of new millennium and mainly in the last 5 years exNA are intensively studied. Main attention is directed to investigation of exNA as the source of diagnostic material whereas the mechanisms of their generation, as well as mechanisms to providing long-term circulation of exNA in the bloodstream are not established unambiguously. According to some authors, the main source of circulating nucleic acids in blood are the processes of apoptosis and necrosis, while others refer to the possible nucleic acid secretion by healthy and tumor cells. Circulating DNA were found to be stable in the blood for a long time, escaping from the action of DNA hydrolyzing enzymes and are apparently packed in different supramolecular complexes. This review presents the opinions of various authors and evidence in favor of all the theories describingappearance of extracellular DNA, the features of the circulation and structure of the extracellular DNA and factors affecting the time of DNA circulation in blood

In-line hemofiltration minimized extracorporeal membrane oxygenation-related inflammation in a porcine model

We evaluated a pattern for connecting a hemofiltration apparatus after the ECMO oxygenator and observed the effects on the levels of inflammatory cytokines. All animals were anesthetized and ventilated, were randomly divided into 3 groups and observed for 24 h: S group (n = 6) received cannulation and heparin infusion; E group (n = 6) received venovenous (VV)-ECMO and heparin infusion; E+H group (n = 6) received hemofiltration with VV-ECMO placed after the oxygenator and heparin infusion. Hemodynamics, gas exchange parameters and plasma cytokine levels were measured simultaneously. After VV-ECMO, oxygenation was maintained in the E and E+H groups. In the E group, the levels of TNF-α, IL-1β, IL-6 and IL-8 increased markedly in the first 2-6 h and then remained stable from 12-24 h. Concentrations of TNF-α, IL-1β, IL-6 and IL-8 in the E+H group were lower than those in the E group. We concluded that the manner of connecting the hemofiltration apparatus after the oxygenator helped maintain adequate oxygenation and was easy to perform. Connecting hemofiltration to ECMO minimized the ECMO-associated effects of pro-inflammatory cytokines.

Short-term continuous high-volume hemofiltration on clinical outcomes of severe acute pancreatitis

OBJECTIVES

This study aimed to conduct a single-center prospective trial of short-term continuous high-volume hemofiltration (HVHF) in patients with predicted severe acute pancreatitis (SAP).

METHODS

Patients with acute pancreatitis with Acute Physiology and Chronic Health Evaluation II scores of greater than 15 on admission between January 2008 and December 2010 were allocated to receive either optimal standard therapy or 72 hours of continuous HVHF on an alternate basis, beginning as soon as possible after admission. Biomarkers and clinical outcomes were compared between the 2 groups.

RESULTS

A total of 61 patients received either conventional therapy (n = 29) or HVHF (n = 32). High-volume hemofiltration treatment was associated with a significant reduction in the incidence of renal failure (P = 0.013), infected pancreatic necrosis (P = 0.048), length of hospitalization (P = 0.005), mortality (P = 0.033), as well as duration of renal (P < 0.001), respiratory (P = 0.002), and hepatic failure (P = 0.001). Acute Physiology and Chronic Health Evaluation II score and C-reactive protein and interleukin 6 levels were significantly reduced after the start of HVHF on days 1, 3, and 7 (all, P < 0.05).

CONCLUSIONS

This study suggests that short-term HVHF may reduce local and systemic complications and mortality in patients with SAP with Acute Physiology and Chronic Health Evaluation score of greater than 15.

Guanylate cyclase inhibition by methylene blue in circulatory shock caused by acute necrotizing pancreatitis: a word of caution based on a porcine model

OBJECTIVE

To study the therapeutic application of guanylate cyclase inhibition by methylene blue in an experimental model of acute pancreatitis in pigs.

METHODS

acute necrotizing pancreatitis was induced in anesthetized pigs by the retrograde infusion of 1 ml/kg of 5% sodium taurocholate and 8 U/kg enterokinase in the pancreatic duct. Three groups were studied (n = 5): control (C), pancreatitis (AP), and MB bolus followed by pancreatitis (MB+P). The data included serum and abdominal fluid enzymes, hemodynamic variables, arterial hemogasometry, abdominal fluid volume, inflammatory markers, plasma nitrite/nitrate (NOx), plasma myeloperoxidase (MPO) and plasma malondialdehyde (MDA). One- and two-way analysis of variance (ANOVA) was performed, followed by the Bonferroni test (p < 0.05).

RESULTS

amylase and lipase were three and 10-fold higher in the AP group. Myeloperoxidase activity was 50% higher in the AP group. The hemodynamic data indicated early hypovolemic shock followed by cardiogenic shock. Severe fluid translocation to the peritoneal cavity was observed. Plasma NOx remained unchanged. The MB+P group had a five-fold increase in MDA compared with the C group.

CONCLUSION

preemptive application of MB in pigs with AP demonstrated no significant effects on hemodynamic and inflammatory variables. The use of MB is inadequate in cases of exponential NO release, and extreme caution must be exercised, given the increase in lipid peroxidation based on the malondialdehyde dosage.

Continuous renal replacement therapy reduces the systemic and pulmonary inflammation induced by venovenous extracorporeal membrane oxygenation in a porcine model

Pulmonary changes in veno-venous extracorporeal membrane oxygenation (VV-ECMO) are rarely determined. We compared the contribution of VV-ECMO and cannulation based on the observation of pulmonary inflammatory reaction and parenchymal construction in a porcine model of low tidal volume (VT ) ventilation. We also evaluated the effect of adding continuous renal replacement therapy (CRRT) to the ECMO circuit, because CRRT is known to reduce systemic cytokine release induced by VV-ECMO. A total of 18 pigs undergoing low-VT ventilation were randomly divided into three groups (group 1, cannulation; group 2, VV-ECMO; group 3, VV-ECMO + CRRT) and studied for 24 h. Hemodynamic and ventilation parameters were recorded. We assessed plasma and alveolar cytokines, expression of pulmonary inflammatory genes, histopathological grading, and ultrastructural changes of the lungs. During the process, inspiratory volume increased and PaO2 decreased in group 1. Systemic tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) levels increased at 2 h in group 2 and partly decreased in group 3. At 24 h, the levels of bronchoalveolar lavage fluid, TNF-α, and IL-6 in group 2 were remarkably higher than those in groups 1 and 3. Pulmonary mRNA expression of cytokines did not differ between the groups. We observed an increased score of pulmonary pathological findings in pro-inflammatory cell infiltration and interstitial thickening of the lungs in group 2. The epithelium of the blood-air barrier after VV-ECMO was swollen. In group 3, the pulmonary parenchyma and blood-air barrier were well preserved. We concluded that in a porcine model of low-VT ventilation, both VV-ECMO and VV-ECMO in combination with CRRT provided adequate oxygenation and carbon dioxide removal. Compared with VV-ECMO alone, VV-ECMO in combination with CRRT better preserved the lung parenchyma by eliminating systemic cytokines.

Portal vein cytokines in the early phase of acute experimental oedematous and necrotizing porcine pancreatitis

OBJECTIVE

Cytokines initiate and modify systemic inflammatory response in early acute pancreatitis. The aim of this study was to analyze which cytokines are released from the pancreas to portal venous blood in the early phase of acute experimental necrotizing and oedematous pancreatitis and which of those cytokines are correlated with the more severe form of the disease.

MATERIAL AND METHODS

Fifteen pigs were randomized to develop mild oedematous pancreatitis (n = 5, saline infusion to pancreatic duct), severe necrotizing pancreatitis (n = 5, taurocholic acid infusion) along with a control group (n = 5). Arterial and venous blood samples were drawn and cytokine levels were measured from portal vein blood at 0, 120, 240 and 360 min after the induction of pancreatitis. Tissue samples from the pancreas were harvested at 0 and 360 min.

RESULTS

White blood cell count increased in necrotizing pancreatitis and the control group. The amount of neutrophils increased (p < 0.001) and the lymphocyte and eosinophil counts decreased in all groups (p < 0.001, p < 0.001). The monocyte count, as well as PDGF and IL-6 concentrations, increased only in necrotizing pancreatitis. IL-8 and eotaxin increased both in oedematous and necrotizing pancreatitis. MCP-1 increased in all groups. IL-9, IL-4, MIP-1α, IFN- γ concentrations did not change. Eotaxin and MCP-1 plasma levels from a previous series between portal venous and pulmonary arterial blood were not significantly different.

CONCLUSIONS

The initial inflammatory process was diverse in oedematous and necrotizing pancreatitis. Increased monocyte count in combination with elevated PDGF and IL-6 are characteristic of necrotizing pancreatitis in our model.

Clinical effects of pulse high-volume hemofiltration on severe acute pancreatitis complicated with multiple organ dysfunction syndrome

To evaluate the effects of pulse high-volume hemofiltration (PHVHF) on severe acute pancreatitis (SAP) with multiple organ dysfunction syndrome (MODS). Thirty patients were divided into two groups: PHVHF group and continuous venovenous hemofiltration (CVVH) group. They were evaluated in terms of clinical symptoms, acute physiology and chronic health evaluation (APACHE) II score, sequential organ failure assessment (SOFA) score, simplified acute physiology (SAPS) II score and biochemical changes. The levels of IL-6, IL-10 and TNF-α in plasma were assessed by ELISA before and after treatment. The doses of dopamine used in shock patients were also analyzed. In the two groups, symptoms were markedly improved after treatment. Body temperature (BT), breath rate (BR), heart rate (HR), APACHE II score, SOFA score, SAPS II score, serum amylase, white blood cell count and C-reactive protein were decreased after hemofiltration (P < 0.05). The PHVHF group was superior to the CVVH group, especially in APACHE II score, CRP (P < 0.01), HR, temperature, SOFA score and SAPS II score (P < 0.05). The doses of dopamine for shock patients were also decreased in the two groups (P < 0.05), with more reduction in the PHVHF group than the CVVH group (P < 0.05). The levels of IL-6, IL-10 and TNF-α decreased (P < 0.05) in the PHVHF group more significantly than the CVVH group (P < 0.01). PHVHF appears to be superior to CVVH in the treatment of SAP with MODS.

Beneficial effect of hypertonic saline resuscitation in a porcine model of severe acute pancreatitis

OBJECTIVE

Hypertonic saline (HTS) solution resuscitation has been used in a variety of clinical settings. The aim of this study was to assess the effect of HTS resuscitation on hemodynamics, systemic oxygenation, and organ damage in a porcine model of severe acute pancreatitis.

METHODS

Eighteen anesthetized and mechanically ventilated pigs were divided into 3 groups: HTS group, lactated Ringer solution (LR) group, and sham-operated group. Severe acute pancreatitis was induced in the first 2 groups by injecting 5% sodium taurocholate into the pancreatic duct, and the investigation period was 12 hours. Hemodynamic parameters, urine output, oxygenation parameters, and serum parameters were recorded consecutively. Finally, histologic examinations of the kidney, intestine, pancreas, and lung were performed.

RESULTS

In the HTS group, cardiac output decreased less significantly compared with the LR group. Furthermore, aspartate aminotransferase, creatinine, and lactate levels increased significantly in all animals with severe acute pancreatitis, but the increasing tendency was slower in the HTS group. Nevertheless, the histopathologic analysis revealed similar injuries of the kidney, intestine, pancreas, and lung between the HTS and LR groups.

CONCLUSIONS

Early administration of HTS generally improves hemodynamics and peripheral oxygenation. Despite these normalized parameters, organ damage could not be diminished to a significant degree during observation.

Adjunctive continuous high-volume hemofiltration in patients with acute severe pancreatitis: a prospective nonrandomized study

OBJECTIVES

To evaluate the efficacy of adjunctive continuous high-volume hemofiltration (HVHF) in patients with severe acute pancreatitis.

METHODS

Seventy-five patients admitted to the intensive care unit for severe acute pancreatitis from July 2006 to May 2009 were given informed consent and were followed prospectively. Patients were divided into 4 groups according to whether they accepted continuous HVHF (42 vs 33) and if they showed signs of acute kidney injury.

RESULTS

Patients of the 4 groups were comparable at baseline. The 28-day survival rate was higher in patients who accepted HVHF (81% vs 57.6%, P=0.026), especially in those without acute kidney injury (95% vs 66.7, P=0.026). Furthermore, after 72 hours of therapy, the patients who accepted HVHF had significantly better Acute Physiology and Chronic Health Evaluation II scores (16.8±4.37 vs 13.39±3.17; P<0.05), body temperature (38.2°C±1.01°C vs 37.73°C±0.95°C; P<0.05), urine volume (1186±841 mL vs 2381±2462 mL; P<0.05), and base excess (-6.3±4.5 vs 0.64±3.4; P<0.05). However, the improvement in patients who did not accept HVHF was not so obviously.

CONCLUSION

High-volume hemofiltration was associated with improved clinical outcome in acute pancreatitis patients, and should be initiated before kidney injury appearance.

Establishment of a secondary infection model of severe acute pancreatitis in swine

OBJECTIVE

Develop a swine model of secondary infection in severe acute pancreatitis (SAP).

METHODS

Twenty-seven female swine were divided into 3 groups (1-3). In the first experiment, a SAP model was developed by retrograde injection of sodium taurocholate and trypsin into the pancreatic duct. In the second experiment, the SAP model was used to develop a secondary infection model. In groups 1 to 3, 10⁸/mL or 10⁴/mL Escherichia coli or saline were respectively used to inoculate necrotic areas of the pancreas using computed tomographic guidance. Biochemical, histopathological, and imaging analyses were used to characterize disease presentation.

RESULTS

The survival rate was 85.2% (23/27) during the course of the 9-day experiment. The secondary infection rates in groups 1 to 3 were 100% (8/8), 37.5% (3/8), and 14.3% (1/7), respectively. In group 1, the infection rate was significantly higher in comparison to the other 2 groups (χ²=4.66 and 8.14, respectively, and both P<0.05). The biochemical and histopathological parameters and computed tomographic images indicated successful development of the SAP secondary infection model.

CONCLUSIONS

The swine model of SAP secondary infection was successfully developed using a 2-step method, which could serve as a platform for SAP studies that need complex experimental manipulations for longer time spans, especially for imaging research.

Adjunctive continuous high-volume hemofiltration in acute severe pancreatitis patients: a retrospective study

OBJECTIVE. To evaluate the efficacy of continuous high-volume hemofiltration for the treatment of severe acute pancreatitis patients and the impact of acute physiology and chronic health evaluation (APACHE) II score on the efficacy of high-volume hemofiltration. MATERIAL AND METHODS. A total of 63 patients diagnosed with severe acute pancreatitis between January 2005 and July 2007 were retrospectively analyzed: 34 accepted adjunctive continuous high-volume hemofiltration (HVHF group); and 29 only accepted conventional recommended treatments (control group). RESULTS. There were no differences in physiological characteristics between the two groups when entering the intensive care unit. After treatment, the percentages of patients successfully weaned from mechanical ventilation (p = 0.004) and who experienced renal function recovery (p = 0.046) were significantly higher in the HVHF group than in the control group. The 28-day survival rate was 91.2% in the HVHF group, compared with 65.5% in the control group (p = 0.014). For patients with APACHE II scores > 15, survival was significant higher in the HVHF group than in the control group (87.5% vs 50%; p = 0.044). No difference in survival was found in patients with APACHE II scores < or = 15 between the two groups (94.4% vs 76.5%; p = 0.177). After HVHF therapy, APACHE II score, body temperature, urine volume and laboratory indices, including serum creatinine, base excess and blood calcium, were significantly improved. CONCLUSIONS. Adjunctive continuous HVHF was beneficial for the survival of severe acute pancreatitis patients. Survival improvement was significant in patients with APACHE II score > 15.

Rheologic reflection in hypertriglyceridemia-induced pancreatitis

Triglyceride levels greater than 1,000 mg/dL may cause severe pancreatitis, and there is mounting evidence for the use of plasmapheresis to remove triglycerides for the treatment of triglyceride-induced pancreatitis. The failure of continuous venovenous hemodialysis (CVVHD) due to severe lipemia, necessitating plasmapheresis in the early phase of severe acute hypertriglyceridemia-induced pancreatitis, is reported. We suggest that in the setting of hypertriglyceridemia-induced pancreatitis with urgent indication for dialysis, plasmapheresis be initiated prior to CVVHD to prevent rheologic failure.

Fluid resuscitation in acute pancreatitis

Acute pancreatitis is a common inflammatory disorder of the pancreas resulting in considerable morbidity and a mortality rate of approximately 5%. Although there are no pharmacologic treatments known to improve important outcomes, aggressive intravenous fluid resuscitation generally is recommended in all patients. However, few human investigations have been performed and several important questions have not been answered. For example, what is the optimal resuscitative fluid? Is there a role for colloid solutions? To what clinical marker should resuscitation be targeted? When is the best time to start such fluids and in which group of patients? This review describes the microcirculation of the pancreas and the pathophysiologic alterations caused by acute pancreatitis. Previous animal experiments are described, as are the limited human studies specifically addressing fluid resuscitation. Finally, current recommendations and goals for further investigation are highlighted. It is our hope that this review will stimulate interest in this often overlooked subject and lead to carefully designed human clinical trials using varying fluid solutions and rates, with an emphasis on patient monitoring and safety, in the near future.

Management of sepsis in patients with liver failure

PURPOSE OF REVIEW

Sepsis constitutes the most common cause of death in the ICU. Liver dysfunction is manifested among previously normal subjects with sepsis but even more so in populations with preexisting liver disease. Managing these patients is more challenging. We will review recent literature in sepsis and liver disease, and their bedside application.

RECENT FINDINGS

At the cellular-chemical level, studies showed that platelet aggregation and neutrophil activation occur before and are independent of microcirculatory changes which are apparent in all animal septic models. At the clinical level, early goal-directed therapy, euglycemia, low tidal volume ventilation, and early and appropriately dosed renal replacement therapy among others are all tools to improve sepsis survival. Acknowledgement of liver disease as an immunocompromised host, and identification and treatment of complications can positively change the outcome of sepsis in liver disease.

SUMMARY

Much has been advanced in the field of sepsis management. Understanding the pathophysiology of liver dysfunction and decompensation of a diseased liver incites questions for future research. Early goal-directed therapy, lactate clearance, glycemic control, low volume ventilation strategies, nutrition, adrenal insufficiency, renal dysfunction, hepatorenal syndrome prevention and treatment are some of the issues in the management of sepsis, with or without liver disease, that are relevant in this review.