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

Effect of Ulinastatin Combined With High-Volume Hemofiltration on Inflammatory Response and MODS Incidence in Severe Sepsis

This study evaluated the impact of ulinastatin combined with high-volume hemofiltration (HVHF) on inflammation and the development of multiple organ dysfunction syndrome (MODS) in severe sepsis. One hundred patients with severe sepsis were recruited and allocated into two groups based on treatment methods (n = 50 patients). The control group underwent HVHF, while the observation group received ulinastatin-assisted HVHF. Comparisons of general data were made in treatment efficacy (APACHE II score), MODS score, and SOFA score. Inflammatory markers and organ function indicators were also measured before and after treatment. The incidence of disseminated intravascular coagulation (DIC), MODS, and mortality rates at 28 days were also analyzed. The observation group showed significantly reduced APACHE II, MODS, and SOFA scores, along with lower levels of IL-6, IL-10, TNF-α, ALT, and Scr (p < 0.05). Additionally, the observation group had lower incidences of DIC, MODS, and mortality (p < 0.05). Furthermore, elevated CD4+ and CD4+/CD8+ ratios while reduced CD8+ levels were noted in the observation group (p < 0.05). We demonstrate that ulinastatin combined with HVHF effectively reduces inflammatory levels in patients with severe sepsis, improves organ function, lowers the incidence of MODS and mortality, and enhances immune function.

Effect of Early Continuous Veno-Venous Haemofiltration in Severe Acute Pancreatitis for the Prevention of Local Pancreatic Complications

Objective

To compare the conventional treatment and continuous veno-venous haemofiltration (CVVH) in severe acute pancreatitis (SAP) for the prevention of pseudocyst and walled-off necrosis. Patients and Methods. Forty-two patients were divided into two treatment groups: conventional treatment group contained 24 patients and CVVH had 18. Conventional treatment group patients were treated symptomatically and according to the causes. CVVH group patients were treated symptomatically, and CVVH was done within 2 hours of admission.

Results

In both groups, there was a decrease in amylase, lipase, CRP, IL-6, IL-10, TNF-alpha, Ranson score, Balthazar score, and APACHE-II score after 72 hours, but the decrease was significantly greater in CVVH patients. There were no any local pancreatic complications in CVVH patients, but 1 patient had an acute peripancreatic fluid collection, 2 patients had pseudocyst, and 2 patients had walled-off necrosis (WON), and a mortality one was seen in the conventional treatment group.

Conclusion

The present study shows that early CVVH may be able to prevent the formation of pseudocyst and win in SAP patients.

[Acute kidney injury following acute pancreatitis (AP-AKI): Definition, Pathophysiology, Diagnosis and Therapy]

Acute pancreatitis (AP) is the most frequent gastrointestinal cause for hospitalization and one of the leading causes of in-hospital deaths. Severe acute pancreatitis is often associated with multiorgan failure and especially with acute kidney injury (AKI). AKI can develop early or late in the course of the disease and is a strong determinator of outcome. The mortality in the case of dialysis-dependent AKI and acute pancreatitis raises exponentially in the affected patients. AP-induced AKI (AP-AKI) shows many similarities but also distinct differences to other causes of AKI occurring in the intensive care unit setting. The knowledge of the exact pathophysiology can help to adjust, control and improve therapeutic approaches to the disease. Unfortunately, there are only a few studies dealing with AP and AKI.In this review, we discuss recent data about pathogenesis, causes and management of AP-AKI in patients with severe acute pancreatitis and exploit in this regard the diagnostic and prognostic potential of respective newer serum and urine markers.

Hemofiltration in Patients with Severe Acute Pancreatitis (Review)

Questions regarding the application of extracorporeal detoxification to patients with severe acute pancreatitis have been considered. Hemodialysis, the historically first method of extracorporeal detoxification for such patients, has been also described in the review. Appropriateness of using renal replacement therapy methods and among them continued renal replacement therapy has been shown. Hemofiltration and hemodiafiltration technologies are described in detail including different modes of their application and the possibility of using various types of filters. Available data on hemofiltration for patients with severe acute pancreatitis have been analyzed. Great attention is paid to the unsolved aspects of hemofiltration in severe acute pancreatitis such as determining renal and extrarenal indices; time of starting hemofiltration; selection of volume replacement modes and a buffer system; procedure duration; anticoagulation measures, defining criteria to assess the adequacy of hemofiltration, state severity, and organ dysfunction degree. Further multicenter investigations are necessary to be able to assess the efficacy of the hemofiltration procedures on the basis of the thoroughly worked out and pathogenically grounded protocol using adequate control methods taking into consideration endogenic intoxication phases and intensity of the multiple organ failure syndrome.

Early Gut Barrier Dysfunction in Patients with Severe Acute Pancreatitis: Attenuated by Continuous Blood Purification Treatment

Objectives

The aim of this study was to investigate the effect of continuous blood purification (CBP) on early gut mucosal dysfunction in patients with severe acute pancreatitis (SAP).

Methods

Patients with SAP were randomized to receive 24 hours of continuous veno-venous hemofiltration (CVVH; n=33) or no CVVH (n=30). Blood samples were taken from the patients at 0, 6, 12, and 24 hours during CVVH therapy. Serum diamine oxidase (DAO) and endotoxin, epithelial permeability, transepithelial electrical resistance (TER) and F-actin rearrangement of the epithelial monolayer were used as the markers for the assessment of gut barrier function and the effect of CBP therapy in patients with SAP.

Results

Patients with SAP had increased levels of serum DAO, endotoxin, and epithelial permeability when compared with normal controls, and the increase was more pronounced in patients with organ dysfunction (p<0.01). F-actin rearrangement, loose cell-cell junction, and iNOS mRNA upregulation were found in all patients. After CBP treatment, Acute Physiology and Chronic Health Evaluation II score and SOFA score improved significantly; levels of serum DAO, endotoxin, and epithelial permeability decreased (p<0.05). CBP also significantly attenuated reorganization of actin and downregulated iNOS mRNA expression and NO production (p<0.05).

Conclusions

CBP can not only improve the general conditions but also effectively improve gut barrier dysfunction. The beneficial effect of CBP on gut barrier dysfunction is associated with the improvement of cytoskeletal instability, by downregulating iNOS through the removal of excess proinflammatory factors.

Crush Syndrome after the Wenchuan Earthquake: New Experience with Regional Citrate Anticoagulation Continuous Veno-Venous Hemofiltration

Purpose

Acute renal failure (ARF) related to crush syndrome is usually treated with hemodialysis. Continuous veno-venous hemofiltration (CVVH) has seldom been adopted in this situation due to the main drawback of continuous anticoagulation. The purpose of this study was to evaluate the effectiveness and safety of regional citrate anticoagulation (RCA)-CVVH in two crush syndrome patients following the Wenchaun earthquake.

Methods

Two victims from the Wenchuan earthquake in Southwest China were admitted to our hospital on May 23, 2008, 11 days after their injury. The total entrapment time under the rubble was 5.5 and 22.5 hrs respectively. They remained oliguric on admission, in spite of vigorous treatment in the local hospital including aggressive fluid infusion, fasciotomy and intermittent hemodialysis. On admission, their serum myoglobin levels were 765 and 829 ng/mL, respectively. Further debridement and drainage were performed. RCA-CVVH was conducted; the citrate containing substitution fluid was infused in a pre-dilution manner at a rate of 4 l/h; calcium was infused through a separate access to the venous inlet of the double lumen catheter. The infusion rate was adjusted according to the serum ionized calcium and whole blood activated clotting time (WBACT). A low dose of low molecular weight heparin (LMWH) was infused at the rate of 150∼300 U/h simultaneously for anticoagulation after anemia had been corrected and their wounds were stable. RCA-CVVH was substituted by conventional CVVH and LMWH anticoagulation when case 2 complicated with hypoxia.

Results

RCA-CVVH was well tolerated, hemodynamic status was stable, and no complications related with RCA-CVVH were noted. The body temperature and WBC decreased to normal range, while anemia and hypoalbuminia were corrected. The levels of serum myoglobin and creatine phosphokinase were also decreased to normal range. Their urine volume increased after 20 and 22 days of oliguria and the tubular function of the patients recovered well. Although the second case encountered acute cholecystitis and acute lung injury in the hospital, both the patients recuperated and neither of them underwent amputation.

Conclusions

The present two crush patients have been successfully treated, but due to the limits of the small sample, it is difficult to generalize whether RCA-CVVH is safe enough for crush syndrome with a high risk of bleeding diathesis. Additional investigation with a larger number of patients is required. Fluid equilibrium, nutritional support, prevention of bleeding and infection are fundamental in this situation.

Improvement of Monocyte Secretion Function in a Porcine Pancreatitis Model by Continuous Dose-Dependent Veno-Venous Hemofiltration

Objective

Monocyte and its secreted cytokines play a crucial role in the process of severe acute pancreatitis (SAP). It has been known that continuous veno-venous hemofiltration (CVVH) can partially attenuate the inflammatory process by removal of cytokines, but the effect of CVVH on monocyte secretion function remains unknown. This study investigated the effect of different doses of CVVH on monocyte secretion function as well as the plasma cytokine profile in a SAP porcine model.

Methods

After successful induction of SAP by pressure-controlled (100 mmHg), intraductal injection of sodium taurocholate (4%, 1 ml/kg) and trypsin (2 U/kg), 24 swine were randomly assigned to 3 groups. Swine in group I (n=8) serving as SAP controls received only standard medical therapy (SMT). Besides SMT, swine in two other groups received zero-balanced CVVH, one hour after the induction of SAP, with low volume fluid exchange (group II, n=8, ultrafiltration rate (UFR) 20 ml/kg/h, LV-CVVH) or high volume (group III, n=8, UFR 100 ml/kg/h, HV-CVVH). Using heparin as anticoagulant, the filter (AN69, Hospal, Lyon, France) was changed every 24 hours. Monocytes were isolated from porcine blood at various timepoints for detection of cytokine secretion (interleukin-6, IL-6; interleukin-10, IL-10; tumor necrosis-α, TNF-α) after LPS stimulus; plasma cytokines were measured simultaneously.

Results

CVVH showed a dose-dependent beneficial effect on the animals’ survival time. In control animals, plasma pro-inflammatory cytokine levels exhibited a double-phase fluctuation after SAP induction: IL-6 and TNF-α rapidly increased to a peak level within 6–12 hours, then dropped to very low level in the late stage. Unlike pro-inflammatory cytokines, the plasma level of anti-inflammatory cytokine IL-10 reached a plateau within 6–12 hours but dropped little. In CVVH-treated animals, the peak-nadir patterns of 3 cytokines were all flattened, most prominently in the HV-CVVH group. Similarly to plasma cytokine patterns, the monocyte ex vivo response to LPS stimulus showed an over-production of cytokines within 6–12 hours, but low production in the late stage. Although unable to totally prevent the abnormality of the monocyte secretion function, CVVH showed a dose-dependent ameliorative effect on it.

Conclusions

Monocytes are over-reactive to stimulus in the early stage of SAP, accompanied by a high level of plasma cytokines, and hypo-reactive to stimulus in the late stage of SAP, accompanied with a low level of plasma cytokines. CVVH treatment has a dose-dependent improvement effect on monocyte responsiveness.

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.

Acute kidney injury following acute pancreatitis: A review

BACKROUND. Acute kidney injury (AKI) is a common serious complication of severe acute pancreatitis (SAP) and an important marker of morbidity and mortality in critically ill septic patients. AKI due to severe acute pancreatitis can be the result of hypoxemia, release of pancreatic amylase from the injured pancreas with impairment of renal microcirculation, decrease in renal perfusion pressure due to abdominal compartment syndrome, intraabdominal hypertension or hypovolemia. Endotoxins and reactive oxygen species (ROS) also play an important role in the pathophysiology of SAP and AKI. Knowledge of the pathophysiology and diagnosis of AKI following SAP might improve the therapeutic outcome of critically ill patients.

METHODS AND RESULTS

An overview of the pathophysiology, diagnosis and potential treatment options based on a literature search of clinical human and experimental studies from 1987 to 2013.

CONCLUSIONS

Early recognition of AKI and SAP in order to prevent severe complication like septic shock, intraabdominal hypertension or abdominal compartment syndrome leading to multiple organ dysfunction syndrome is a crucial tool of therapeutic measures in intensive care.

Is continuous venovenous hemofiltration effective against severe acute pancreatitis?

Our aim was to investigate the efficacy of continuous venovenous hemofiltration (CVVH) in treating severe acute pancreatitis (SAP). A literature search was performed using PubMed (1992-present), and all studies investigating the efficacy of CVVH in treating SAP were included. Four comparative studies and seven case series comprising a total of 354 patients were included. The overall mortality rate of patients receiving CVVH was 20% (55/275). A decreased mortality rate and decreased serum cytokine levels were reported in the CVVH groups in only two studies. The starting time point, substitution fluid flow rate, filter membrane type, hemofilter change interval, anticoagulation, and sustaining times of CVVH varied among the studies, and the impact of these parameters on the efficacy of CVVH was poorly reported. High-volume CVVH, when started early, was demonstrated to be more effective in eliminating cytokines in only one study. After the application of CVVH, the patient conditions started to improve between the 6th and 72nd hours. In conclusion, no solid clinical evidence has proven the efficacy of CVVH in treating SAP. High-volume CVVH that is started early and sustained for at least 72 h may be adopted to investigate the efficacy of CVVH for treating SAP.

Hemoperfusion plus continuous veno-venous hemofiltration in a pregnant woman with severe acute pancreatitis: a case report

Severe acute pancreatitis is a common critical disease, which may cause severe complications such as sepsis and multiple organ dysfunction syndrome (MODS), and has a high mortality. A 31-year-old woman with 25-weeks pregnancy presented with hyperlipidemic pancreatitis, sepsis and MODS. Based on conventional treatment, 125 h of continuous veno-venous hemofiltration (CVVH) and 3 sessions of hemoperfusion (HP) were carried out. The treatment turned out to be very successful. We suggest that early intervention by blood purification therapy, and CVVH combined with HP could be effective in severe acute pancreatitis.

Effects of high-volume hemofiltration on alveolar-arterial oxygen exchange in patients with refractory septic shock

BACKGROUND

High-volume hemofiltration (HVHF) is technically possible in severe acute pancreatitis (SAP) patients complicated with multiple organ dysfunction syndrome (MODS). Continuous HVHF is expected to become a beneficial adjunct therapy for SAP complicated with MODS. In this study, we aimed to explore the effects of fluid resuscitation and HVHF on alveolar-arterial oxygen exchange, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score in patients with refractory septic shock.

METHODS

A total of 89 refractory septic shock patients, who were admitted to ICU, the Provincial Hospital affiliated to Shandong University from August 2006 to December 2009, were enrolled in this retrospective study. The patients were randomly divided into two groups: fluid resuscitation (group A, n=41), and fluid resuscitation plus high-volume hemofiltration (group B, n=48). The levels of O2 content of central venous blood (CcvO2), arterial oxygen content (CaO2), alveolar-arterial oxygen pressure difference P(A-a)DO2, ratio of arterial oxygen pressure/alveolar oxygen pressure (PaO2/PaO2), respiratory index (RI) and oxygenation index (OI) were determined. The oxygen exchange levels of the two groups were examined based on the arterial blood gas analysis at different times (0, 24, 72 hours and 7 days of treatment) in the two groups. The APACHE II score was calculated before and after 7-day treatment in the two groups.

RESULTS

The levels of CcvO2, CaO2 on day 7 in group A were significantly lower than those in group B (CcvO2: 0.60±0.24 vs. 0.72±0.28, P<0.05; CaO2: 0.84±0.43 vs. 0.94±0.46, P<0.05). The level of oxygen extraction rate (O2ER) in group A on the 7th day was significantly higher than that in group B (28.7±2.4 vs. 21.7±3.4, P<0.01). The levels of P(A-a)DO2 and RI in group B on the 7th day were significantly lower than those in group A. The levels of PaO2/PaO2 and OI in group B on 7th day were significantly higher than those in group A (P<0.05 or P<0.01). The APACHE II score in the two groups reduced gradually after 7-day treatment, and the APACHE II score on the 7th day in group B was significantly lower than that in group A (8.2±3.8 vs. 17.2±6.8, P<0.01).

CONCLUSION

HVHF combined with fluid resuscitation can improve alveolar-arterial-oxygen exchange, decrease the APACHE II score in patients with refractory septic shock, and thus it increases the survival rate of patients.

Clinical effects of laparotomy with perioperative continuous peritoneal lavage and postoperative hemofiltration in patients with severe acute pancreatitis

BACKGROUND

The elevated serum and peritoneal cytokine concentrations responsible for the systemic response syndrome (SIRS) and multiorgan failure in patients with severe acute pancreatitis lead to high morbidity and mortality rates. Prompted by reports underlining the importance of reducing circulating inflammatory mediators in severe acute pancreatitis, we designed this study to evaluate the efficiency of laparotomy followed by continuous perioperative peritoneal lavage combined with postoperative continuous venovenous diahemofiltration (CVVDH) in managing critically ill patients refractory to intensive care therapy. As the major clinical outcome variables we measured morbidity, mortality and changes in the Acute Physiology and Chronic Health Evaluation (APACHE II) score and cytokine concentrations in serum and peritoneal lavage fluid over time.

METHODS

From a consecutive group of 23 patients hospitalized for acute pancreatitis, we studied 6 patients all with Apache II scores >/=19, who underwent emergency surgery for acute complications (5 for an abdominal compartment syndrome and 1 for septic shock) followed by continuous perioperative peritoneal lavage and postoperative CVVDH. CVVDH was started within 12 hours after surgery and maintained for at least 72 hours, until the multiorgan dysfunction syndrome improved. Samples were collected from serum, peritoneal lavage fluid and CVVDH dialysate for cytokine assay. Apache II scores were measured daily and their association with cytokine levels was assessed.

RESULTS

All six patients tolerated CVVDH well, and the procedure lasted a mean 6 days (range, 3-12). Five patients survived and one died of Acinetobacter infection after surgery (mortality rate 16.6%). The mean APACHE II score was >/= 19 (range 19-22) before laparotomy and decreased significantly during peritoneal lavage and postoperative CVVDH (P = 0.013 by matched-pairs Students t-test). The decrease in cytokine concentrations in serum and lavage fluid was associated with the decrease in APACHE II scores and high interleukin 6 (IL-6) and tumor necrosis factor (TNF) concentrations in the hemofiltrate.

CONCLUSION

In critically ill patients with abdominal compartment syndrome, septic shock or high APACHE II scores related to severe acute pancreatitis, combining emergency laparotomy with continuous perioperative peritoneal lavage followed by postoperative CVVHD effectively reduces the local and systemic cytokines responsible for multiorgan dysfunction syndrome thus improving patients' outcome.

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.

Kinetics of Group IB and IIA Phospholipase A2 During Low-Volume Continuous Hemodiafiltration in Severe Acute Pancreatitis

Continuous hemodiafiltration (CHDF) has been performed for the treatment of severe acute pancreatitis. Phospholipase A2 (PLA2) is one of the important mediators which exacerbate acute pancreatitis, but whether PLA2 can be removed by CHDF is unclear. In this study, the kinetics of group IB and group IIA PLA2 was examined at the first session of low-volume CHDF in eight patients with severe acute pancreatitis. CHDF was performed using polysulfone hemofilters (surface area: 0.7 m(2)) at a blood flow rate of 100 mL/min and a filtration and dialysate flow rate of 10 mL/min each. The plasma concentrations of group IB and IIA PLA2 before the start of CHDF were 47.4 +/- 52.0 microg/L and 352 +/- 390 microg/L, respectively, and did not change significantly. The clearances of group IB and IIA PLA2 achieved by the CHDF circuit 1 h after the start of CHDF were 20.7 +/- 11.6 mL/min and 16.7 +/- 4.4 mL/min, respectively, with both clearances decreasing significantly with time. The clearance of group IB PLA2 into the waste fluid tended to increase with time; however, the concentrations of group IIA PLA2 in the waste fluid were less than the measurable sensitivity. These results indicate that group IB PLA2 is adsorbed on the hemofilter membrane in preference to being removed into the waste fluid, while group IIA PLA2 is mainly removed by adsorption. However, low-volume CHDF is not effective at eliminating the group IB and IIA PLA2 plasma concentration.

Low-Volume Continuous Hemodiafiltration With Nafamostat Mesilate Increases Trypsin Clearance Without Decreasing Plasma Trypsin Concentration in Severe Acute Pancreatitis

Continuous hemodiafiltration (CHDF) has recently been used for treatment of severe acute pancreatitis. CHDF is capable of eliminating small molecules from blood, but whether trypsin can be eliminated by CHDF is not clear. In this study, elimination of trypsin-like enzyme activity (TLE) and cationic trypsin-like immunoreactivity (TLI) using low-volume CHDF was examined at the first CHDF session in eight patients with severe acute pancreatitis. CHDF was performed with a polysulfone hemofilter (membrane area, 0.7 m2) and nafamostat mesilate, a protease inhibitor and anticoagulant, at a blood flow rate of 100 ml/min and a filtration and dialysis flow rate of 10 ml/min each. Before beginning CHDF, plasma TLE was 3.41 +/- 2.86 nmol/(ml.min), and TLI was 5,900 +/- 9,008 ng/ml. The average plasma clearances of TLE and TLI achieved by the circuit during the 12-hour therapy were 56.7 +/- 4.9 ml/min and 8.0 +/- 7.2 ml/min, respectively. The average plasma clearance of TLI into the waste fluid was 2.4 +/- 1.6 ml/min whereas TLE was below the measurable sensitivity. The plasma concentration of TLE and TLI remained unchanged. These results indicate that low-volume CHDF using nafamostat mesilate as an anticoagulant can increase trypsin plasma clearance. However, low-volume CHDF is not effective to eliminate the plasma trypsin concentration.

Hemofiltration in sepsis and systemic inflammatory response syndrome: the role of dosing and timing

INTRODUCTION

The benefit of hemofiltration (HF) as an adjunctive treatment of sepsis or the systemic inflammatory response syndrome (SIRS) in critically ill patients is a subject of severe debate. Firm conclusions on this subject are hampered by the heterogeneity in study populations and HF treatments, and the lack of adequately sized randomized controlled clinical trials. The aim of this review was to determine the importance of ultrafiltration dose and timing on the physiologic and clinical effects of HF in sepsis and SIRS. In addition, we discuss the issue of filter pore size.

METHODS

Literature search was done in Embase and PubMed database for animal and human studies.

RESULTS

Animal studies suggest beneficial effects of HF on hemodynamics; gas exchange; sepsis-induced immunoparalysis; histology of gut, lung, and kidney; and (short-term) survival. These effects were more prominent with "very high" ultrafiltrate rates (> or =100 mL/kg per hour) and early initiation of HF (ie, before or very early after the septic challenge). Three small randomized studies and 3 observational studies in patients with sepsis or SIRS show beneficial effects of short-term or pulse HF using very high ultrafiltrate rates and/or early initiation of HF on physiologic endpoints and survival. However, the studies were underpowered for survival. The first observations of high permeability HF (pore size, about 10 nm; in vitro cutoff, 100 kd) are promising, but so far, it has not been sufficiently examined to allow strong conclusions.

CONCLUSION

Human and animal studies suggest that early initiation and high ultrafiltrate volumes are determinants of the beneficial physiologic and clinical effect of HF in sepsis and SIRS. As yet, the evidence in humans is too low to recommend HF as an adjunctive therapy for critically ill patients with sepsis or SIRS. Regarding the many uncertainties about optimal volume (high or very high) and type of membrane, clinical studies should first focus on endpoints as recovery from organ failure and length of treatment before survival studies are started.

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

OBJECTIVE

To compare the effects of different doses of hemofiltration on severe acute pancreatitis (SAP) in pigs.

METHODS

The animal model of SAP was produced by intraductal injection of sodium taurocholate and trypsin. Animals in group 1 served as SAP control. Animals in group 2 received (20 mL/kg per hour) continuous low-volume hemofiltration (LVHF), and animals in group 3 received (100 mL/kg per hour) continuous high-volume hemofiltration (HVHF) immediately after the induction of SAP. After the instrumentation of the animals by arterial and Swan-Ganz catheters, hemodynamic indexes were monitored intermittently at different times. The rectal temperature and the concentration of amylase and cytokines in serum were measured at the same time.

RESULTS

The survival time of HVHF group was significantly prolonged (P < 0.01). The initial elevation of body temperature and the hypothermia in the late course of experiments were significantly ameliorated by HVHF (P < 0.01). Six hours after the induction of pancreatitis, the urine output of animals in HVHF group was obviously higher than that in control group (P < 0.05), which stayed behind 36 hours later (P < 0.05). The major hemodynamic finding was that pancreatitis-induced hypotension was significantly attenuated by HVHF (P < 0.01). The development of hyperdynamic circulatory failure was simultaneously attenuated, as reflected by a limited increase in CI, an attenuated decrease in systemic vascular resistance index. Plasma amylases in the HVHF group were significantly lower than those in control and LVHF groups (P < 0.01). The serum concentrations of cytokines such as tumor necrosis factor alpha (TNF-alpha), interleukin (IL) 6, and IL-10 all decreased significantly in treatment groups (P < 0.01), and those of HVHF group were less significant than the HVHF group (P < 0.01).

CONCLUSIONS

The HVHF was associated with a better hemodynamic profile, a less hyperkinetic state, and more prolonged survival than that of LVHF, which may result from the HVHF that can remove the inflammatory cytokines more efficiently.

Continuous veno-venous haemofiltration in the treatment of severe acute pancreatitis: 6-year experience

BACKGROUND

Continuous veno-venous haemofiltration (CVVH) could be reasonable for attenuation of systemic complications in severe acute pancreatitis (SAP). The aim of the study was implementation and feasibility assessment of the CVVH in the treatment protocol of SAP.

PATIENTS AND METHODS

CVVH was applied to 111 SAP patients during 2000-2005. APACHE II, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), serum lipase, C-reactive protein (CRP), complication rate and main outcomes were analysed comparing two periods.

RESULTS

Overall, 39 patients corresponded to Balthazar grade E SAP and 72 patients to necrotizing SAP (NSAP), with an average APACHE II score of 7 and 8.5, respectively, on admission. CVVH was started within 48 h in 82% of patients. Duration of CVVH was significantly augmented in NSAP patients during the routine period, comprising 92 h (p=0.006). The clinical presentation of SIRS and MODS was similar in both periods, with more initial pulmonary dysfunctions in NSAP (p=0.048). Peripancreatic infection decreased in the routine period; surgical interventions were performed in 34.8% vs 72.4% of patients. Hospital stay comprised on average 15.9 days for grade E SAP and 29.4 days for NSAP in the routine period, with overall mortality of 10.26% and 30.5%, respectively.

DISCUSSION

Application of CVVH in the treatment protocol of SAP is obscure due to relative invasiveness, a poorly understood mechanism of action and scarce clinical experience. We conclude that early pre-emptive application of CVVH is safe and feasible in the treatment of SAP. Duration of the procedure seems to be essential. Randomized clinical trials are justified. Our results are in favour of clinical application of CVVH in the treatment of SAP.

Effects of high-volume continuous hemofiltration on experimental pancreatitis associated lung injury in pigs

OBJECTIVE

To investigate the effect of high-volume continuous hemofiltration on experimental pancreatitis associated lung injury (PALI) in pigs.

METHODS

Animals had severe acute pancreatitis (SAP) induced by intraductal injection of sodium taurocholate and trypsin and were randomly assigned to three groups: 1) Controls, 2) Low-volume (LV) (20 ml/kg/h) continuous venovenous hemofiltration (CVVH) and 3) High-volume (HV) (100 ml/kg/h) CVVH at the onset of the induction of SAP. Systemic and pulmonary hemodynamic index were monitored intermittently. At the same time, arterial oxygen tension (PaO 2 ), cytokines and activated NF- ê B levels of peripheral blood mononuclear cell were measured. After the animals died, the degree of microscopic lung injury was judged and scored.

RESULTS

The median survival times of control, low-volume and high-volume groups were respectively 41 h, 50 h and 65 h. Temperatures in high-volume CVVH group were more steady than in control and LV CVVH groups (p<0.01). MPAP was significantly decreased by 4-5 mmHg in the HV CVVH group after 12 h of treatment. PaO(2) was significantly higher in HV group than in LV group at 6 h , 12 h, 24 h and 48 h (p<0.01). HV CVVH resulted in significant reductions not only in interstitial edema and atelectasis but also hemorrhages, hyaline membranes, microthrombi and total lung injury histology score. Plasma cytokines in the high-volume group were significantly lower than in the LV and control groups. In the HV group, the expression of NF- ê B activation at 6 h, 12 h and 24 h was lower than in the control and LV groups respectively.

CONCLUSION

CVVH can reduce pulmonary edema and the severity of PALI in pigs with high-volume CVVH being significantly better than low-volume CVVH. The beneficial effects of CVVH on arterial oxygenation and pulmonary function may be connected with improvements in systemic hemodynamics, reduction in plasma cytokine concentration and decreased activity of NF- ê B in peripheral blood mononuclear cells.

Increased intra-abdominal pressure: is it of any consequence in severe acute pancreatitis?

BACKGROUND

Increased intra-abdominal pressure (IAP) is detrimental for the recovery of organ function in trauma and emergency patients. The aim of this study was to assess the correlation between the dynamics of IAP and organ dysfunction in severe acute pancreatitis (SAP).

MATERIALS AND METHODS

Management of SAP between 2000 and 2004 was analysed. SAP was classified according to Atlanta 1992. Organ dysfunction, systemic inflammatory response syndrome (SIRS) and outcomes in relation to the IAP were assessed. IAP was measured indirectly.

RESULTS

A total of 65 patients, with an average APACHE II score of 6.44, complied with the Atlanta criteria. In all, 34 patients received conservative treatment and 31 were operated. SIRS was observed in 59 cases and multiple organ dysfunction syndrome (MODS) in 61 cases. IAP was significantly higher in the 25 most complicated patients requiring renal replacement therapy (RRT), compared with 40 patients without RRT, 31.72 vs 21.4 cm/H(2)O (p=0.037). IAP interrelated positively with SOFA score (r = + 0.371, p<0.01) and organs involved (r = + 0.356, p<0.01), and negatively with platelet count and enterally provided volume (r = - 0.284, p<0.01; r = - 0.5, p<0.01, respectively). Overall mortality (9.2%) was associated with surgery and sustained increase of the IAP over 25 cm/H(2)O. Our data support the pathophysiological interrelation of elevated IAP and development of organ dysfunction.

CONCLUSION

Development of organ dysfunction in SAP could be associated with increased IAP. Grade III increase of IAP should be considered as an indicator for revision of treatment modalities.

Amelioration of hemodynamics and oxygen metabolism by continuous venovenous hemofiltration in experimental porcine pancreatitis

AIM: To investigate the potential role of continuous venovenous hemofiltration (CVVH) in hemodynamics and oxygen metabolism in pigs with severe acute pancreatitis (SAP).

METHODS: SAP model was produced by intraductal injection of sodium taurocholate [4%, 1 mL/kg body weight (BW)] and trypsin (2 U/kg BW). Animals were allocated either to untreated controls as group 1 or to one of two treatment groups as group 2 receiving a low-volume CVVH [20 mL/(kg.h)], and group 3 receiving a high-volume CVVH [100 (mL/kg.h)]. Swan-Ganz catheter was inserted during the operation. Heart rate, arterial blood pressure, cardiac output, mean pulmonary arterial pressure, pulmonary arterial wedge pressure, central venous pressure, systemic vascular resistance, oxygen delivery, oxygen consumption, oxygen extraction ratio, as well as survival of pigs were evaluated in the study.

RESULTS: Survival time was significantly prolonged by low-volume and high-volume CVVHs, which was more pronounced in the latter. High-volume CVVH was significantly superior compared with less intensive treatment modalities (low-volume CVVH) in systemic inflammatory reaction protection. The major hemodynamic finding was that pancreatitis-induced hypotension was significantly attenuated by intensive CVVH (87.4±12.5 kPa vs 116.3±7.8 kPa, P<0.01). The development of hyperdynamic circulatory failure was simultaneously attenuated, as reflected by a limited increase in cardiac output, an attenuated decrease in systemic vascular resistance and an elevation in oxygen extraction ratio.

CONCLUSION: CVVH blunts the pancreatitis-induced cardiovascular response and increases tissue oxygen extraction. The high-volume CVVH is distinctly superior in preventing sepsis-related hemodynamic impairment.

Mechanism of hemofiltration in treatment of severe acute pancreatitis

AIM: To study the mechanism of hemofiltration in the reduction of systemic inflammatory response in severe acute pancreatitis (SAP).

METHODS: A mixture composed of sodium taurocholate (50 g/L) and bile was antidromicly injected into pancreatic duct of dogs to establish SAP model. Two hours later, hemofiltration was performed (last 2 h). Heart rate, as well as the acute injury scores of lung, liver and pancreas were compared between model and test groups. Nuclear translocation of nuclear factor-κB (NF-κB) was detected by Western blotting, and TNF-α mRNA expression was determined by reverse transcription-polymerase chain reaction. Then the therapeutic mechanism of hemofiltration in SAP was analyzed.

RESULTS: Significant decrease of heart rates was observed 8 and 12 h after the hemofiltration (P = 0.0 181 < 0.05, P = 0.0 141 < 0.05 respectively). Hemofiltration resulted in reduction of pulmonary pathological score (1 ± 0.63 vs 2.83 ± 0.75, P = 0.001 < 0.01), but did not affect hepatic and pancreatic ones. NF-κB nuclear translocation and TNF-α expression were inhibited by hemofiltration both in lung and in liver.

CONCLUSION: Hemofiltration ameliorates pulmonary and hepatic inflammatory response induced by SAP. This may relate to removal of the over-produced pro-inflammatory cytokines from circulation.

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Effects of antioxidant on NF-κB and iNOS in rats with acute necrotizing pancreatitis

AIM: To observe the influence of antioxidant N-acetylcysteine (NAC) on nuclear factor-kappa B (NF-κB) and inducible nitric oxide synthase (iNOS) in pancreatic tissue of rats with acute necrotizing pancreatitis (ANP).

METHODS: A total of 95 Spraque-Dawley (SD) male rats were randomly divided into control group (group C, n = 25), acute pancreatitis group (group A, n = 35) and NAC intervention group (group N, n = 35). In group A, SD rats were injected twice intraperitoneally with 8 g/L L-arginine (2×1.2 mg/g) in an interval of 1 hour for ANP. In group C, SD rats received the same amount of saline at the same time. In group N, 0.5 mol/L NAC (0.05 mg/g) was administered intraperitoneally 1 hour before the start of L-arginine injection. Animals were killed at 6, 12, 24, 36, and 48 hours after the first L-arginine injection. The concentration of NF-κB and the activity of iNOS in rat's pancreatic tissue of each group were assayed.

RESULTS: The concentration of NF-κB in pancreatic tissue in group N significantly decreased in earlier period than that in group A (10.4±2.3 vs 89.7±6.4, 6.8±3.2 vs 21.5±3.5, 7.9±3.4 vs 32.5±4.5, 5.4±2.7 vs 14.7±5.2, and 5.0±3.7 vs 11.1±2.3, P < 0.05 or P < 0.01). iNOS activity increased in group A, whereas it significantly decreased in group N (15.2± 4.0 vs 24.2±3.8, 28.3±8.0 vs 36.8±6.0, 25.2±3.8 vs 30.5±3.5 , 21.2±3.7 vs 28.7±7.2, and 18.8±5.5 vs 28.2±4.2, P < 0.05 or P < 0.01).

CONCLUSION: Antioxidants may decrease the activity of iNOS through the inhibition of NF-κB activation.