Continuous hemofiltration/hemodiafiltration in critical care

Multicenter study on the consciousness-regaining effect of a newly developed artificial liver support system in acute liver failure: An on-line continuous hemodiafiltration system

AIM

Acute liver failure (ALF) patients with coma need to be revived not only for spontaneous recovery but also as a bridge to liver transplantation. We developed a new high-volume plasma purification system using an on-line continuous hemodiafiltration (CHDF) system, and evaluated its safety and efficacy in a multicenter study.

METHODS

A single arm interventional study using the new apparatus was undertaken in the six major liver centers in Japan. The primary end-point was the proportion of patients who regained consciousness within 10 days, which was compared with a historical control (47%). Nine ALF patients were enrolled and treated with the new machine. One patient was excluded because of the need for artificial respiration support according to the established protocol.

RESULTS

Seven of eight (87.5%) patients regained consciousness during the on-line CHDF session, with five of those seven waking within 4 days. After waking, one patient spontaneously recovered, three received liver transplantation, two died of liver failure, and one died of another disease. The plasma ammonia levels significantly decreased after the start of on-line CHDF from 182.5 ± 64.8 μg/dL (mean ± SD) on day 0 to 87.0 ± 38.9 μg/dL on the last day of the session (P < 0.001). Similarly, the plasma glutamine level also significantly decreased from 2069 ± 1234 μmol/L to 628 ± 193 μmol/L. Although seven severe adverse events occurred during on-line-CHDF, no causal relationship with liver support was recognized.

CONCLUSIONS

The newly developed on-line CHDF system showed high efficacy for regain of consciousness and excellent therapeutic safety for managing ALF.

Vorapaxar-modified polysulfone membrane with high hemocompatibility inhibits thrombosis

Hemodialysis therapy is intended for patients suffering from renal insufficiency, pancreatitis, and other serious diseases. Platelets are an important active ingredient in the thrombosis induced by hemodialysis membranes. So far, there are few studies of hemodialysis membranes focusing on the effects of protease-activated receptor 1 (PAR1) activation on the platelet membrane. Among various antithrombotic agents, vorapaxar is a novel PAR1 inhibitor with high efficacy. In this study, we constructed a vorapaxar-modified polysulfone (VMPSf) membrane using immersion-precipitation phase transformation methods and characterized the microstructure in terms of hydrophilicity and mechanical properties. The water contact angle of the VMPSf membrane was 22.45% lower than that of the PSf membrane. A focused determination of platelet morphology was obtained using scanning electron microscopy. Meanwhile, we evaluated the effects of a VMPSf membrane on platelet adhesion. We observed that the VMPSf membrane could reduce the number of adhered platelets without altering their spherical or elliptical shape. The PAR1 levels in VMPSf membranes were 7.4 MFI lower than those in PSf membranes, suggesting that this modified membrane can effectively inhibit platelet activation. Activated partial thromboplastin time (APTT, 5.3 s extension) and thrombin time (TT, 2.1 s extension) reflect good anticoagulant properties. Recalcification time (80.6 s extension) and fibrinogen adsorption (9.9 μg/cm² reduction) were related to antithrombotic properties. To determine the biosafety of VMPSf membranes, we investigated antianaphylactic and anti-inflammatory properties in vitro and acute toxicity in vivo, it was obvious that C3a and C5a had decreased to 9.6 and 0.8 ng/mL, respectively. The results indicated that the VMPSf membrane has potential for clinical application.

Posthepatectomy liver failure

Liver surgery is one of the most complex surgical interventions with high risk and potential for complications. Posthepatectomy liver failure (PHLF) is a serious complication of liver surgery that occurs in about 10% of patients undergoing major liver surgery. It is the main source of morbidity and mortality. Appropriate surgical techniques and intensive care management are important in preventing PHLF. Early start of the liver support systems is very important for the PHLF patient to recover, survive, or be ready for a liver transplant. Nonbiological and biological liver support systems should be used in PHLF to prepare for treatment or organ transplantation. The definition of the state, underlying pathophysiology and treatment strategies will be reviewed here.

A case series of the dynamics of lipid mediators in patients with sepsis

Background

Bioactive lipid mediators play a crucial role during infection. Previously, we showed the expression level of FAAHmRNA in septic patients was lower than in healthy controls.

Case Presentation

Four patients with a Sequential Organ Failure Assessment (SOFA) score of <7 recovered from sepsis. One patient with SOFA score of 12 on day 7 died on day 21. In the fatal case, eicosapentaenoic acid, docosahexaenoic acid, arachidonic acid, and linoleic acid‐derived lipid mediators, including 9‐hydroxyoctadecadienoic acid (9‐HODE), 13‐HODE, 9,10‐dihydroxy‐12‐octadecenoic acid (9,10‐DiHOME), and 12,13‐DiHOME, were elevated on day 1. Increase in anti‐inflammatory prostaglandin E₁ ethanolamide together with persistently lower transcription level of FAAHmRNA was detected on day 7 in the fatal case.

Conclusion

Lipidomic analysis on day 1 revealed elevated linoleic acid metabolites, whereas on day 7, elevated prostaglandin E₁ ethanolamide and low level of FAAHmRNA transcription were observed in the fatal case of sepsis.

Changes in acute blood purification therapy in critical care: republication of the article published in the Japanese Journal of Artificial Organs

Acute blood purification therapy is an essential artificial organ in critical care. In the review article, looking back on the history, we describe our present knowledge and techniques of acute blood purification therapy in critical care. The topics include continuous hemodiafiltration (CHDF), online HDF as an artificial liver support, blood purification therapy aiming to remove pathogenic substances of sepsis, a procedure for connecting a CRRT device into an extra-corporeal membrane oxygenation circuit, and replacement fluid for CHDF. We also raise remaining issues and clarify the future direction of acute blood purification therapy in critical care. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2017 (Vol. 46, No. 1, pp. 67-70), with adding some references.

Hearing recovery from deafness caused by bromate intoxication

OBJECTIVES

Sodium bromate is a strong oxidant, and bromate intoxication can cause irreversible severe-to-profound sensorineural hearing loss. This paper reports the first case in the English literature of bromate-induced hearing loss with hearing recovery measured by formal audiological assessment.Case reportA 72-year-old woman was admitted to hospital with complaints of profound hearing loss, nausea, diarrhoea and anuria after bromate ingestion in a suicide attempt. On admission, pure tone audiometry and auditory brainstem responses showed profound bilateral deafness. Under the diagnosis of bromate-induced acute renal failure and sensorineural hearing loss, continuous haemodiafiltration was performed. When dialysis was discontinued, pure tone audiometry and auditory brainstem responses showed partial threshold recovery from profound deafness.

CONCLUSION

Severe-to-profound sensorineural hearing loss is a common symptom of bromate intoxication. Bromate-induced hearing loss may be partially treated, and early application of continuous haemodiafiltration might be useful as a treatment for this intractable condition.

Continuous blood purification ameliorates clinical signs and corrects the plasma phospholipid levels of patients with multiple organ dysfunction syndromes

BACKGROUND

Multiple organ dysfunction syndromes (MODS) is reported as a leading cause of mortality in intensive care units. Recently, continuous blood purification (CBP) has been mostly applied for MODS treatment. Thus, the purpose of this study was to investigate the effects of CBP on plasma phospholipid level in patients with MODS.

METHODS

A total of 126 patients with MODS and 120 healthy people were collected. The serum cytokine levels, blood biochemical parameters, and blood gas indexes were detected, and the correlation among phospholipid compounds with serum cytokine levels, blood biochemical parameters, and blood gas indexes was analyzed.

RESULTS

Before CBP, levels of body temperature, RR, HR, CVP, IL-6, IL-10, TNF-α, BUN, SCr, PaCO₂ , SM747, and LPC540 were obviously higher, and pH, HCO_3- , PaO₂ , SaO₂ , PE750, PI885, PC792, PC826, PC830, PC854, PC802, and PG747 were lower in the MODS group than those in the control group. During CBP, the MODS group had gradually declined RR, CVP, levels of IL-6, IL-10 and TNF-α, BUN, SCr, PaCO₂ , SM747, and LPC540 and increased HCO_3- , PaO₂ and SaO₂ , PE750, PI885, PC792, PC826, PC830, PC854, PC802, and PG747. Besides, levels of PE750, PI885, PC792, PC826, PC830, PC854, PC802, and PG747 had an obvious negative correlation with levels of TNF-α, IL-10, IL-6, BUN, SCr, and PaCO₂ , and a significant positive correlation with levels of HCO_3- , PaO₂ , and SaO₂ .

CONCLUSION

CBP could effectively ameliorate clinical signs of patients with MODS and correct the plasma phospholipid levels.

A Novel Bioartificial Liver Containing Small Tissue Fragments: Efficiency in the Treatment of Acute Hepatic Failure Induced by Carbon Tetrachloride in Rats

The efficiency of a new bioartificial liver (BAL) containing small tissue fragments in the treatment of acute hepatic failure induced by carbon tetrachloride in rats was evaluated. A day after injection (i.p.) of CCl4 the animals were connected to a BAL containing liver fragments (fragment BAL) and a BAL containing no liver fragments (no-fragment BAL), and extracorporeal hemoperfusion was carried out for 4 h. The activities of alanine transaminase and lactate dehydrogenase as well as the concentrations of ammonia, glucose, urea, and amino acids in plasma were measured. A tendency to the stabilisation of ammonia, glucose, phenylalanine, tyrosine, and other amino acids was revealed at the end of hemoperfusion in poisoned rats connected to the fragment BAL. A statistically significant difference in survival between the animals connected to the fragment BAL and no-fragment BAL was found. The results obtained indicate that the bioreactor containing small liver fragments is effective in the treatment of acute hepatic failure in animals.

Pharmacokinetics of linezolid during continuous hemodiafiltration: A case report

The pharmacokinetics of linezolid clearance (CL_LZD) during continuous hemodiafiltration (CHDF) has not been comprehensively analyzed. Here, we examined CL_LZD by CHDF in a patient with septic shock and disseminated intravascular coagulation due to methicillin-resistant Staphylococcus aureus. The extraction ratio of LZD by CHDF was 22.6%, and the protein-binding rate was 17.9% ± 7.7%. In addition, it was determined that the calculated total body clearance of LZD was 30.2 mL/min, plasma elimination half-life was 8.66 h, and the CL_LZD by the dialyzer used for CHDF was 23.0 mL/min. From the obtained pharmacokinetics, the CL_LZD of patients continuing CHDF was estimated to be approximately half of the reported CL_LZD for healthy subjects. In addition, the LZD concentration of the sepsis patient who underwent CHDF remained higher than the minimum inhibitory concentration and was similar to the LZD concentrations reported in normal renal function patients. Although further studies are warranted, when LZD is administered to patients treated with CHDF, the present findings suggest that dose regulation is not required.

Improving RhoA-mediated intestinal epithelial permeability by continuous blood purification in patients with severe acute pancreatitis

BACKGROUND

Early dysfunction of the intestinal mucosal barrier contributes to increasing intestinal permeability. It may play an important role in the pathophysiology of severe acute pancreatitis (SAP). A rising number of clinical data have showed that continuous blood purification (CBP) may improve the prognosis of SAP. However, the therapeutic effects of CBP on intestinal epithelial permeability have been rarely reported.

METHODS

Intestinal epithelial monolayer (Caco-2) was incubated with serum samples collected at specific time points from SAP patients during CBP. Changes in intestinal epithelial monolayer permeability and configuration, and levels of cellular tight junction structural proteins including occludin and ZO-1, and RhoA mRNA expression level were recorded, respectively. In addition, serum tumor necrosis factor-alpha (TNF-α) levels at specific time points during CBP were determined.

RESULTS

Before CBP initiation, intestinal epithelial permeability was increased and tight junction structural protein level was decreased and reorganized, but RhoA mRNA expression and serum TNF-α were increased. However, after CBP treatment, intestinal epithelial permeability was reduced and tight junction protein levels were increased, with reorganization attenuated. Meanwhile, RhoA mRNA expression and serum TNF-α level was decreased.

CONCLUSIONS

After CBP treatment, intestinal epithelial permeability was reduced by increasing occludin and ZO-1 protein level and attenuating reorganization. This beneficial effect of CBP on intestinal epithelial permeability is associated with down-regulation of RhoA mRNA expression, and it may be related to the removal of TNF-α by CBP.

Continuous blood purification ameliorates endothelial hyperpermeability in SAP patients with MODS by regulating tight junction proteins via ROCK

BACKGROUND

Excessive activation of inflammatory mediator cascade during severe acute pancreatitis (SAP) is a major cause of multiple organ dysfunction and is associated with a high mortality. Recently, more and more studies have shown that continuous blood purification (CBP) could improve the prognosis of patients with multiple organ dysfunction syndrome (MODS), but the exact mechanism is still unclear. Many researchers have found that the disruption of tight junction barrier was an important factor for endothelial hyperpermeability, which played a key role in the pathogenesis of MODS. Previously, we found CBP could attenuate endothelial hyperpermeability in SAP patients with lung injury through regulating cytoskeleton reorganization mediated by RhoA/ROCK. However, the effect of CBP on the change of tight junction proteins in SAP patients with MODS was still unknown. This study aimed to investigate the role of tight junctions in endothelial hyperpermeability in SAP patients with MODS using an in vitro model, and the effect of CBP on tight junction barrier.


METHODS

Before CBP and after CBP, blood samples were collected to observe hepatic and renal function, and arterial blood gas, while the APACHE II score was calculated to evaluate the severity of patients. To test whether RhoA/ROCK signaling pathway was involved, human umbilical vein endothelial cells (HUVECs) were exposed to serum samples taken from patients at specific time points during CBP, or preincubated with ROCK inhibitor, Y-27632, followed by treatment with serum. Then, the changes in endothelial cell permeability and the expression and distribution of tight junction proteins occludin and claudin-1 were observed. 


RESULTS

Compared with before CBP, the APACHE II score, serum creatinine and alanine aminotransferase decreased significantly, while PaO2/FiO2 increased significantly after CBP. Meanwhile, endothelial permeability induced by serum from patients significantly increased, while the expression of tight junction proteins occludin and claudin-1 significantly decreased, and severe disruption of occludin and claudin-1 was found in these cells. However, pretreated with Rho-kinase inhibitor, Y-27632 could lessen all of these abnormalities, and in a dose-dependent way. Endothelial hyperpermeability, the abnormal expression and distribution of occludin and claudin-1 were attenuated in HUVECs treated with serum from patients after CBP treatment. 


CONCLUSIONS

The abnormality of tight junctions mediated by ROCK was an important mechanism for endothelial hyperpermeability induced by serum from SAP patients with MODS. CBP could ameliorate the disorganization and redistribution of tight junction proteins, hence improve the endothelial permeability.

Treatment of septic shock with continuous HDF using 2 PMMA hemofilters for enhanced intensity

PURPOSE

Cytokines play pivotal roles in the pathophysiology of severe sepsis/septic shock, and continuous hemodiafiltration using a polymethylmethacrylate membrane hemofilter (PMMA-CHDF) removes cytokines efficiently and continuously, mainly through adsorption to a hemofilter membrane. The aim of this study was to investigate the clinical efficacy of enhanced intensity PMMA-CHDF in treating refractory septic shock.

METHODS

Seventy-two septic shock patients admitted to the intensive care unit (ICU) underwent critical care including PMMA-CHDF. We employed enhanced intensity PMMA-CHDF to improve the cytokine removal rate by increasing the hemofilter membrane area in 10 refractory septic shock patients (enhanced intensity group, EI group; 2 extracorporeal CHDF circuits using the hemofilter with a larger membrane area of 2.1 m2). Other patients undergoing conventional PMMA-CHDF and matched for severity with the EI group, comprised a matched conventional group (MC group; using a PMMA membrane hemofilter with a membrane area of 1.0 m2; n=15). The case-control comparison was performed between the 2 groups.

RESULTS

Enhanced intensity PMMA-CHDF significantly increased mean arterial pressure by 23.8% in 1 hour (p=0.037), decreased the blood lactate level by 28.6% in 12 hours (p=0.006), and reduced blood IL-6 level in 24 hours (p=0.005). The ICU survival rate in the EI group was significantly better than that in the MC group (60% vs. 13.3%, p=0.028).

CONCLUSION

Enhanced intensity PMMA-CHDF may improve hemodynamics and survival rate in patients with refractory septic shock.

Continuous blood purification ameliorates RhoA-mediated endothelial permeability in severe acute pancreatitis patients with lung injury

BACKGROUND

In the early phase of severe acute pancreatitis (SAP), serious pulmonary complications which are directly correlated with mortality are very common. Endothelial injury has been shown to play a key role in the pathogenesis of ALI/ARDS. Continuous blood purification (CBP) has been widely used in treating patients with multiple organ dysfunction syndrome (MODS) including ARDS. However, the impact of CBP on endothelial function has been little studied.

METHODS

Human umbilical vein endothelial cells (HUVECs) were exposed to serum samples or replacement fluid taken from patients at specific time points during CBP, or pretreated with Y-27632 followed by treatment with serum, then, changes in cytoskeletal configuration, endothelial monolayer permeability, and RhoA activation were studied.

RESULTS

Endothelial permeability, RhoA activity, and stress fiber reorganization increased in HUVECs treated with serum from patients before CBP initiation, and lessened in HUVECs treated with serum from patients after CBP initiation. Endothelial hyperpermeability and stress fiber reorganization reduced in HUVECs pretreated with Rho-kinase inhibitor, Y-27632, and in a dose-dependent fashion. Endothelial permeability and RhoA activity increased in HUVECs treated with waste replacement fluid collected 2 h after CBP initiation.

CONCLUSIONS

After CBP treatment, endothelial hyperpermeability induced by serum from SAP patients with lung injury was reduced. The inhibition of RhoA-mediated F-actin remodeling might be the mechanism.

Evaluation of a new polysulfone hemofilter for continuous renal replacement therapy

New strategies using continuous renal replacement therapy as a tool to achieve immunomodulation in septic acute kidney injury have been proposed. The hypothesis is based on the possibility to remove inflammatory mediators and oxidants in a wide spectrum of molecular weights, thanks to new, highly permeable synthetic membranes. A new polysulfone hemofilter with high permeability and a sharp high cut-off membrane (CUREFLO™; Asahi Kasei Kuraray Medical Co., Ltd., Tokyo, Japan) has been evaluated in this study to assess IL-6 and advanced oxidation protein product removal in critically ill patients undergoing continuous renal replacement therapy. Unit performance, sieving coefficients and clearances were evaluated in fourteen patients undergoing continuous veno-venous hemofiltration and continuous veno-venous hemodialysis.

Continuous renal replacement therapy for liver disease

Continuous renal replacement therapy (CRRT) is becoming the treatment of choice for critically ill patients with acute renal failure around the world. In particular, CRRT is used for patients with combined liver and acute renal failure, because they are often hemodynamically unstable. The question arises as to whether the use of CRRT should be extended to those patients with acute and chronic liver failure who do not have dialysis-dependent renal failure. CRRT could potentially allow some detoxification by removing water-soluble toxins and also allow regulation of intravascular volume and correction of sodium and other electrolyte and acid-base imbalances. By providing homeostatic control, CCRT could potentially help support patients by bridging to liver transplantation and managing those who eventually recover with hepatic regeneration.

The role of hypercytokinemia in the pathophysiology of tumor lysis syndrome (TLS) and the treatment with continuous hemodiafiltration using a polymethylmethacrylate membrane hemofilter (PMMA-CHDF)

OBJECTIVE

To examine the role of hypercytokinemia in the pathophysiology of tumor lysis syndrome (TLS) and the efficacy of continuous hemodiafiltration in the treatment of TLS.

DESIGN AND SETTING

Retrospective observational study in a general intensive care unit of a university hospital.

PATIENTS

Four patients with hematological disorder developing TLS after the treatment of anti-tumor chemotherapy.

INTERVENTIONS

Continuous hemodiafiltration using a polymethylmethacrylate membrane hemofilter (PMMA-CHDF) was performed at the onset of TLS. Blood samples were collected daily after ICU admission, and clinical parameters and blood levels of cytokines were evaluated.

MEASUREMENTS AND RESULTS

All four patients underwent induction anti-tumor chemotherapy, during which they developed hyperuricemia, hyperkalemia, and acute renal failure. Two of them also developed multiple organ failure. Serum levels of tumor necrosis factor (TNF) -alpha, interleukin-6 (IL-6), and IL-10 prior to the initiation of PMMA-CHDF were 102+/-85 pg/mL, 1097+/-546 pg/mL, and 98+/-83 pg/mL, respectively (mean +/- SD). After three days of PMMA-CHDF treatment, corresponding blood levels were 37+/-55 pg/mL, 326+/-511pg/mL, and 9+/-8 pg/mL, respectively. Thus, all cytokine levels were significantly decreased by three days of PMMA-CHDF treatment (p<0.05, paired t-test). Following three days of PMMA-CHDF treatment, blood urea nitrogen (BUN) and serum creatinine (Cre.) were significantly decreased (pre/post BUN 42.3+/-15.4/16.5+/-8.4 mg/dL, p<0.05, pre/post Cre. 2.7+/-1.2/1.2+/-0.6 mg/dL, mean +/- SD, p<0.05). Furthermore, the clinical condition of each patient was improved after the treatment of PMMA-CHDF, and all of four patients were survived.

CONCLUSION

Hypercytokinemia plays a pivotal role in the pathophysiology of TLS and PMMA-CHDF may be an effective therapeutic modality for TLS patients not only as renal replacement therapy but also as a cytokine modulator.

Comparison of efficacy between continuous hemodiafiltration with a PMMA membrane hemofilter and a PAN membrane hemofilter in the treatment of a patient with septic acute renal failure

The aim of this study was to investigate whether PMMA-CHDF in the treatment of a patient with septic acute renal failure (septic ARF) is clinically relevant. Thirteen patients were treated with PMMA-CHDF. Thirteen patients were treated with PAN-CHDF. The urinary output significantly increased in PMMA-CHDF group following 24h of the treatment (p<0.05), whereas those did not improve in PAN-CHDF group. The 28-day survival was 84.6% in PMMA-CHDF group and 38.5% in PAN-CHDF group, respectively (p<0.05). We can assume that the cytokine modulation with PMMA-CHDF in the treatment of patients with septic ARF is clinically relevant.

Continuous hemodiafiltration with PMMA Hemofilter in the treatment of patients with septic shock

Septic shock is the most severe form of sepsis. It is widely accepted that cytokines play pivotal roles in the pathophysiology of septic shock. We reported previously that continuous hemodiafiltration (CHDF) using a polymethylmethacrylate (PMMA) membrane hemofilter removed various cytokines from blood continuously and efficiently, mainly by adsorption to membrane matrix of the hemofilter. Furthermore, in April 2000, we introduced to clinical practice a rapid assay system that determines blood levels of IL (interleukin)-6 in approximately 30 min. This enabled us to routinely measure blood IL-6 as an index of cytokine cascade activation in critically ill patients for real-time clinical monitoring of hypercytokinemia. The aim of the present cohort study was to evaluate the clinical efficacy of PMMA-CHDF in septic shock, a typical condition associated with hypercytokinemia. Forty-three patients with septic shock were assessed by monitoring of blood IL-6 level with a rapid assay system and immediate initiation of critical care including PMMA-CHDF for cytokine removal. Following initiation of PMMA-CHDF, early improvement of hemodynamics was noted, as well as an increase in urine output. PMMA-CHDF treatment improved both hypercytokinemia (assessed by measurement of blood IL-6 level) and dysoxia (assessed by measurement of blood lactate level). The present findings suggest that cytokine-oriented critical care using PMMA-CHDF might be an effective strategy for the treatment of septic shock.

Stenotrophomonas maltophilia bacteremia after living donor liver transplantation: Report of a case

Stenotrophomonas maltophilia (previously named Xanthomonas maltophilia) is an aerobic, nonfermentive, Gram-negative bacillus that is widespread in the environment. It is considered to be an organism with a limited pathogenic potential, which is rarely capable of causing diseases in humans other than in those who are in an immunocompromised state. In this study, we outline the case of a patient with Stenotrophomonas maltophilia bacteremia after living donor liver transplantation, which showed the clinical signs of severe sepsis and was resistant to almost all antibiotics. However, we successfully treated the patient with the antibiotics trimethoprim-sulfamethoxazole (TMP/SMX) and minocycline hydrochloride (MINO), and performed endotoxin-absorbing therapy using polymyxin B (PMX) to remove the endotoxin from Gram-negative bacillus as well as continuous hemodiafiltration (CHDF) to remove inflammatory cytokines. To the best of our knowledge, this is the first report on the treatment of Stenotrophomonas maltophilia bacteremia after living donor liver transplantation.

Direct hemoperfusion with a cytokine-adsorbing device for the treatment of persistent or severe hypercytokinemia: a pilot study

BACKGROUND/AIMS

Cytokine overproduction has been noted during the aggravation of clinical conditions. Countermeasures to control hypercytokinemia are therefore important in critical care. We investigated the clinical efficacy of hemoadsorption therapy using a new cytokine-adsorbing device in critically ill patients with persistent or severe hypercytokinemia.

METHODS

Direct hemoperfusion using the CYT-860, a cytokine-adsorber column (CYT-860-DHP), was performed in critically ill patients with hypercytokinemia. To evaluate the efficacy of CYT-860-DHP, changes in pathological and clinical parameters were examined.

RESULTS

Seven patients with hypercytokinemia and a SOFA score of > or = 5 underwent CYT-860-DHP treatment. Four patients survived 28 days after CYT-860-DHP treatment. Significant decreases in blood levels of cytokines were observed. PaO2/F(I)O2 improved significantly.

CONCLUSION

The possibility that CYT-860-DHP treatment can reduce blood cytokine levels and thereby improve the general condition of patients was suggested. These findings warrant the initiation of a prospective randomized trial to evaluate the clinical efficacy of CYT-860-DHP treatment.

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.

Blood purification therapy for sepsis

Accumulating evidences of underlining pathogenesis of sepsis have contributed to the therapeutic strategy for sepsis. Not only endotoxin and cytokine, but also signal transduction through Toll-like receptors could be a strategic target for the management of sepsis. Blood purification therapy including polymyxin B-immobilized hemoperfusion cartridge and continuous hemodiafiltration has shown the beneficial effect on patients with sepsis in Japan. Although they were initially designed to remove endotoxin and cytokines respectively, they might eliminate unexpected mediators responsible for sepsis. Further elucidation of mechanism and randomized controlled studies are needed to establish the role of blood purification therapy in sepsis.

On-line continuous hemodiafiltration in sepsis

On-line products of substitution fluid by bicarbonate buffered dialysate permits virtually unlimited fluid volume exchange during continuous hemodiafiltration (CHDF) to critical care. In on-line hemodiafiltration (HDF), endotoxin free dialysate obtained using pyrogen cut filters is infused into the blood circuit, and HDF is automatically performed using the close-loop balancing system of the dialysis machine. On-line CHDF is the application of this on-line HDF to continuous renal replacement therapy in the critical care field. We performed on-line CHDF of the totally in 123 septic shock patients during a 5-year period and the mean survival rate was 54%. We concluded that on-line CHDF system is safe and effective at maintaining acute kidney injury with sepsis.

Blood purification for hypercytokinemia

Blood purification has been steadily improved in the field of critical care, supported by advances in related biomedical technologies as well as efforts to develop better operating procedures. As it has become clear that hypercytokinemia plays a key role in the pathophysiology of critical pathological conditions, use of various blood purification techniques to control hypercytokinemia has been investigated. Answers to questions concerning the optimal cytokine-removing device (dialyzer/hemofilter/adsorber) as well as operating procedures and conditions of such devices in particular clinical conditions have been obtained in the course of such investigations. The recent success in real-time monitoring of cytokine levels in clinical practice to assess the extent of cytokine network activation may improve the precision and efficacy of blood purification in the treatment of hypercytokinemia. In addition, the recently documented effects of genetic factors on hypercytokinemia suggest that the introduction of tailor-made medicine considering the differences in genetic background among individual patients may improve the efficacy of blood purification as a countermeasure to hypercytokinemia.

Artificial liver support at present and in the future

Liver failure is a fatal disease. Liver transplantation is the only established treatment for liver failure; however, donor shortages remain problematic. In the United States and Europe, artificial livers as a bridge to liver transplantation are being considered. In Japan, we have taken a different approach to the treatment of end-stage liver diseases because of the characteristics of the health-care insurance system, regulated by the government. Furthermore, cadaveric liver transplantations are unsuited to the social mores of Japanese culture. Practically speaking, we believe that plasma exchange (PE) and continuous hemodiafiltration (CHDF) are the most effective therapies for the treatment of liver failure, although randomized controlled studies are needed to determine their effects. Overall, we believe that the first line of treatment for liver failure should be PE and CHDF, and the second line should be bioartificial liver support. In the near future, we hope that both gene therapy and regenerative medicine will contribute to the development of a functional artificial liver.

Blood purification for critical illness: cytokines adsorption therapy

Blood purification therapies have been clinically applied to treat cytokine-induced pathological effects. The effects of broad-spectrum adsorption using Lixelle (beta2-microglobulin adsorption column; Kaneka Corporation, Osaka, Japan) for the condition of hypercytokinemia in vitro, in an animal model and in humans with sepsis were investigated. We found that Lixelle could selectively adsorb not only beta2-microglobulin but also cytokines composed of glycoproteins in vitro. In addition, Lixelle beads could adsorb not only endotoxin (ET) but also microbial fragments such as peptidoglycan (PG) which is a component of Gram-positive bacteria. Hypercytokinemic rats were connected to a direct hemoperfusion (DHP) system using a mini Lixelle column and time-course changes in plasma levels of inflammatory cytokines were examined. In addition, a Lixelle column was used in direct hemoperfusion in patients with systemic inflammatory response syndrome (SIRS), and the relationship between a decrease in cytokines and clinical course was examined. The increases in plasma levels of IL-6 and tumor necrosis factor-alpha (TNF-alpha) were significantly inhibited in the group treated with the Lixelle column in an animal model. In humans with sepsis, for IL-1beta, IL-1Ra, IL-6, IL-8, and TNF-alpha, the adsorbing rates in vivo before and after the use of the Lixelle column tended to decrease with time. However, the reduction rates at 5 min after the start were 31.4, 39.3, 36.4, 76.2 and 71.6%, respectively, and at 3 h after the start, the rates were 18.0, 17.7, 12.9, 31.8, and 32.9%, respectively. Clinically, their blood pressure increased and they recovered from shock status. These results suggest that SIRS and sepsis with hypercytokinemia can be treated with the DHP using the Lixelle column.

Management of intra-abdominal hypertension in patients with severe acute pancreatitis with continuous hemodiafiltration using a polymethyl methacrylate membrane hemofilter

To evaluate, with a prospective observational study, whether continuous hemodiafiltration using a polymethyl methacrylate membrane hemofilter (PMMA-CHDF) is effective for prevention and treatment of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) on patients with severe acute pancreatitis (SAP). The study was carried out in the general intensive care unit (ICU) of a university hospital. Seventeen consecutive patients with SAP were treated in the intensive care unit and underwent PMMA-CHDF whether or not they had renal failure. Blood level of interleukin (IL)-6, as an indicator of cytokine network activation, and intra-abdominal pressure (IAP) were measured daily to investigate their time-course of changes and the correlation between the two. The blood level of IL-6 was high at 1350+/-1540 pg/mL on admission to the ICU. However, it significantly decreased to 679+/-594 pg/mL 24 h after initiation of PMMA-CHDF (P<0.05), and thereafter decreased rapidly. Mean intra-abdominal pressure (IAP) on admission was high, at 14.6+/-5.3 mm Hg, with an IAP of 20 mm Hg or over in 2 of 17 patients, showing that they had already developed IAH. The IAP was significantly lower (P<0.05) 24 h after initiation of PMMA-CHDF, and subsequently decreased. There was a significant positive correlation between blood level of IL-6 and IAP, suggesting that PMMA-CHDF improved vascular permeability through elimination of cytokines, and that it thereby decreased interstitial edema to lower IAP. Sixteen of the 17 patients were discharged from the hospital in remission from SAP without development of complications. Continuous hemodiafiltration using a polymethyl methacrylate membrane hemofilter appears to be effective for prevention and treatment of IAH in patients with SAP through the removal of causative cytokines of hyperpermeability.

Influence of continuous veno-venous hemofiltration on the course of acute pancreatitis

AIM: To investigate whether continuous veno-venous hemofiltration (CVVH) in different filtration rate to eliminate cytokines would result in different efficiency in acute pancreatitis, whether the saturation time of filter membrane was related to different filtration rate, and whether the onset time of CVVH could influence the survival of acute pancreatitis.

METHODS: Thirty-seven patients were classified into four groups randomly. Group 1 underwent low-volume CVVH within 48 h of the onset of abdominal pain (early CVVH, n = 9). Group 2 received low-volume CVVH after 96 h of the onset of abdominal pain (late CVVH, n = 10). Group 3 underwent high-volume CVVH within 48 h of the onset of abdominal pain (early CVVH, n = 9). Group 4 received high-volume CVVH after 96 h of the onset of abdominal pain (late CVVH, n = 9). CVVH was sustained for at least 72 h. Blood was taken before hemofiltration, and ultrafiltrate was collected at the start of CVVH and every 12 h during CVVH period for the purpose of measuring the concentrations of TNF-α, IL-1β and IL-6. The concentrations of TNF-α, IL-1β and IL-6 were measured by swine-specific ELISA. The Solartron 1 255 B frequency response analyzer (British) was used to observe the resistance of filter membrane.

RESULTS: The survival rate had a significant difference (94.44% vs 68.42%, P<0.01) high-volume and low-volume CVVH patients. The survival rate had also a significant difference (88.89% vs 73.68%, P<0.05) between early and late CVVH patients. The hemodynamic deterioration (MAP, HR, CVP) was less severe in groups 4 and 1 than that in group 2, and in group 3 than in group 4. The adsorptive saturation time of filters membranes was 120-180 min if the filtration rate was 1 000-4 000 mL/h. After the first, second and third new hemofilters were changed, serum TNF-α concentrations had a negative correlation with resistance (r: -0.91, -0.89, and -0.86, respectively in group 1; -0.89, -0.85, and -0.76, respectively in group 2; -0.88, -0.92, and -0.82, respectively in group 3; -0.84, -0.87, and -0.79, respectively in group 4). The decreasing extent of TNF-α, IL-1β and IL-6 was significantly different between group 3 and group 1 (TNF-α P<0.05, IL-1β P<0.05, IL-6 P<0.01), between group 4 and group 2 (TNF-α P<0.05, IL-1β P<0.05, IL-6 P<0.01), between group 1 and group 2 (TNF-α P<0.05, IL-1β P<0.05, IL-6 P<0.05), and between group 3 and group 4 (TNF-α P<0.01, IL-1β P<0.01, IL-6 P<0.05), respectively during CVVH period. The decreasing extent of TNF-α and IL-1β was also significantly different between survival patients and dead patients (TNF-α P<0.05, IL-1β P<0.05). In survival patients, serum concentration of TNF-α and IL-1β decreased more significantly than that in dead patients.

CONCLUSION: High-volume and early CVVH improve hemodynamic deterioration and survival in acute pancreatitis patients. High-volume CVVH can eliminate cytokines more efficiently than low-volume CVVH. The survival rate is related to the decrease extent of TNF-α and IL-1β. The adsorptive saturation time of filter membranes are different under different filtration rate condition. The filter should be changed timely once filter membrane adsorption is saturated.

Assessment of resin perfusion in hepatic failure in vitro and in vivo

AIM: To observe the adsorbent effect of resin on endotoxin, cytokine, bilirubin in plasma of patients with hepatic failure and to determine the resin perfusion as an artificial liver support system in the treatment of hepatic failure.

METHODS: One thousand milliliters of discarded plasma was collected from each of 6 severe hepatitis patients treated with plasma exchange. The plasma was passed through a resin perfusion equipment for 1-2 h via extracorporeal circulation, and then absorbent indicators of transaminase, bilirubin, blood ammonia, endotoxin and cytokines were examined. In the meantime, study of in vivo resin plasma perfusion was performed on 7 severe hepatitis patients to compare the changes of endotoxin and cytokines in blood before and after perfusion.

RESULTS: The levels of total bilirubin, endotoxin, interleukin 1β and TNF-α in plasma were significantly decreased after in vitro resin plasma perfusion. The levels of interleukin 1β, TNF-α and endotoxin in blood were also evidently declined after in vivo resin plasma perfusion. Nevertheless, no obvious changes in IL-6, creatinine (Cr) and urea nitrogen (UN), blood ammonia and electrolytes were found both in vitro and in vivo.

CONCLUSION: Bilirubin, endotoxin and cytokines in plasma of patients with hepatic failure can be effectively adsorbed by resin in vitro. Most cytokines and endotoxin in plasma can also be effectively removed by resin in vivo. It demonstrates that resin perfusion may have good treatment efficacy on hepatic failure and can be expected to slow down the progression of hepatic failure.

Clinical characteristics and management of patients with early acute severe pancreatitis: Experience from a medical center in China

AIM: To study clinical characteristics and management of patients with early severe acute pancreatitis (ESAP).

METHODS: Data of 297 patients with severe acute pancreatitis (SAP) admitted to our hospital within 72 h after onset of symptoms from January 1991 to June 2003 were reviewed for the occurrence and development of early severe acute pancreatitis (ESAP). ESAP was defined as presence of organ dysfunction within 72 h after onset of symptoms. Sixty-nine patients had ESAP, 228 patients without organ dysfunction within 72 h after onset of symptoms had SAP. The clinical characteristics, incidence of organ dysfunction during hospitalization and prognosis between ESAP and SAP were compared.

RESULTS: Impairment degree of pancreas (Balthazar CT class) in ESAP was more serious than that in SAP (5.31 ± 0.68 vs 3.68 ± 0.29, P < 0.01). ESAP had a higher mortality than SAP (43.4% vs 2.6%, P < 0.01), and a higher incidence of hypoxemia (85.5% vs 25%, P < 0.01), pancreas infection (15.9% vs 7.5%, P < 0.05), abdominal compartment syndrome (ACS) (78.3% vs 23.2%, P < 0.01) and multiple organ dysfunction syndrome (MODS)(78.3% vs 10.1%, P < 0.01). In multiple logistic regression analysis, the main predisposing factors to ESAP were higher APACHE II score, Balthazar CT class, MODS and hypoxemia.

CONCLUSION: ESAP is characterised by MODS, severe pathological changes of pancreas, early hypoxemia and abdominal compartment syndrome. Given the poor prognosis of ESAP, these patients should be treated in specialized intensive care units with special measures such as close supervision, fluid resuscitation, improvement of hypoxemia, reduction of pancreatic secretion, elimination of inflammatory mediators, prevention and treatment of pancreatic infections.

Catheter-Related Infections in Continuous Hemodiafiltration in Intensive Care Patients

BACKGROUND/AIMS

Infection control is of key importance especially in the application of long-term continuous hemodiafiltration (CHDF) involving invasive vascular catheterization to critically ill patients. We investigated hemodialysis catheter-related infections in long-term CHDF.

METHODS

We examined catheter infections in 54 patients who were admitted to the intensive care unit and underwent CHDF for 2 weeks or longer.

RESULTS

With a total of 155 catheters (1,071 catheter days) studied, catheter colonization and catheter-related bloodstream infection were noted with an incidence rate of 4.8 and 2.7 per 1,000 catheter days, respectively. No difference in catheter colonization rate was observed depending on the catheterization sites or duration of catheterization. Infections were identified in 39 patients (72%) and blood culture positivity was noted in 25 patients (46%).

CONCLUSIONS

Since the majority of cases requiring long-term CHDF are complicated with a variety of infections, it is difficult to control infections associated with hemodialysis catheters separately from infections of other types. Systemic infection control should serve as a strategy finally leading to successful control of catheter-related infection.

Cytokine Adsorptive Property of Various Adsorbents in Immunoadsorption Columns and a Newly Developed Adsorbent: An in vitro Study

BACKGROUND/AIMS

Cytokines play important roles in the pathophysiology of systemic inflammatory response syndrome (SIRS) and sepsis. Therefore, some effective measures to remove cytokines from the bloodstream could be effective in the treatment of SIRS and sepsis. The aim of this study was to evaluate the cytokine adsorptive property of various adsorbents for the purpose of the development of new selective cytokine adsorption columns.

METHODS

The cytokine adsorptive property of adsorbent in a CF-X column, which consists of cellulose beads cross-linked with hexamethylene-di-isocyanate, was compared with those of various adsorbents in currently available immunoadsorption columns, such as Immusorba TR, Immusorba PH, Selesorb, and Lixelle, in vitro batchwise test using patients' plasma. A newly developed adsorbent, MPCF-X, which was modified by coating the surface of the adsorbent in CF-X with 2-methacryloyloxyethyl phosphorylcholine (MPC), was also tested for its cytokine adsorptive property.

RESULTS

The adsorbent in CF-X showed a significantly higher adsorption rate for TNF-alpha, interleukin (IL)-6 and IL-10 compared with other adsorbents (p < 0.05). Adsorbent in Lixelle showed good affinity to TNF-alpha and IL-8. Especially, the adsorbent in CF-X almost completely removed TNF-alpha, whereas it also had considerable affinity to normal IgG. MPCF-X showed decreased affinity to IgG with considerable adsorptive properties to cytokines.

CONCLUSION

Selective cytokine adsorption columns could be developed with improvement of currently available adsorbents. Such a new selective cytokine adsorption column could be clinically applied for the treatment of SIRS/sepsis.

Effect of continuous hemofiltration on hemodynamics, lung inflammation and pulmonary edema in a canine model of acute lung injury

OBJECTIVE

This study examined whether continuous hemofiltration favorably affects cardiopulmonary variables, lung inflammation, and lung fluid balance in a canine model of oleic acid induced acute lung injury.

METHODS

Eleven pentobarbital-anesthetized dogs were randomly divided into a control (mechanical ventilation, MV) group (n=6) and a MV plus hemofiltration (HF) group (n=5). All animals received an intravenous injection of oleic acid (0.09 ml/kg) to induce acute lung injury. Continuous arterial-venous hemofiltration (blood flow 100 ml/min, ultrafiltration rate at 50-65 ml kg(-1) h(-1)) was started after establishment of oleic acid induced acute lung injury and continued for 4 h. Hemodynamics, lung mechanics, gas exchange, lung fluid balance, lung histology, and the level of plasma cytokines were assessed.

RESULTS

After 240 min of HF treatment there was a significant increase in cardiac output, reduction in pulmonary arterial pressure, and improvement in both oxygenation and lung mechanics. Also, in the HF group the lung wet-to-dry weight ratio was significantly reduced. Histologically, HF reduced edema and inflammatory cell infiltration in the lung. There was also a significantly greater decrease in plasma IL-6 and IL-8 levels in the HF group than in group receiving MV alone.

CONCLUSIONS

In a canine model of acute lung injury continuous HF improved cardiopulmonary function, reduced pulmonary edema, decreased lung permeability and inflammation, and decreased the plasma concentration of proinflammatory cytokines.

Factors predisposing to severe acute pancreatitis: evaluation and prevention

AIM: To analyze factors predisposing to the infections associated with severe acute pancreatitis (SAP) and to work out ways for its prevention.

METHODS: Total 208 cases of SAP treated in this hospital from Jan. 1980 to Dec. 2001 were retrospectively analyzed.

RESULTS: Statistical difference in the incidence of the aforementioned infections was found between the following pairs: between the groups of bloody or non-bloody ascites, paralytic ileus lasting shorter or longer than 5 days, Ranson scores lower or higher than 5, hematocrit lower or higher than 45%, CT Balthazar scores lower or higher than 7 and between 1980.1-1992.6 or 1992.7-2001.12 admissions (χ² > 3.84, P < 0.05), while no statistical difference was established between the groups of biliogenic and non-biliogenic pancreatitis, serum amylase < 200 U/L and ≥ 200 U/L, serum calcium < 2 mmol/L and ≥ 2 mmol/L or groups of total parenteral nutrition shorter or longer than 7 days (χ² < 3.84, P > 0.05).

CONCLUSION: Occurrence of infection in patients with SAP is closely related with bloody ascites, paralytic ileus ≥ 5 days, Ranson scores ≥ 5, hematocrit ≥ 45% and CT Balthazar Scores ≥ 7, but not with pathogens, serum calcium and total parenteral nutrition (TPN). Comprehensive prevention of pancreatic infection and practice of individualized therapy contribute to reducing the incidence of infection.

Effects of time interval for hemofiltration on the prognosis of severe acute pancreatitis

AIM: To evaluate the impact of time interval for hemofiltration (HF) on the prognosis of severe acute pancreatitis (SAP).

METHODS: Thirty-six consecutive patients with severe acute pancreatitis were included in the study. Atlanta classification system was applied for stratification. They were randomly divided into short veno-venous HF group, (SVVH, Group 1, 20 patients); and long veno-venous HF group (LVVH, Group 2, 16 patients). In group 1, SVVH was stopped when the abdominal signs disappeared, and heart rate and breath rate were less than 90 beats/min and 20 times/min, respectively. HF was stopped if SVVH was continued, and when heart rate and breath rate were more than 90 beats/min and 20 times/min again (Group 2). Except that the time interval for HF was different, other parameters for HF were the same. And conservative curing rate, survival rate, cost for hospital stay and length of hospital stay were observed.

RESULTS: Time interval for HF in Group 1 (3.81 ± 1.3 h) was shorter than that of in Group 2 (9.38 ± 2.9 hr), P < 0.01. Conservative curing rate (90%) in Group 1 was much higher than that in Group 2 (56.3%) (P < 0.05); but cost in Group 1 (RMB 56600 ± 56400 Yuan) was lower than that in Group 2 (RMB 137000 ± 105000 Yuan) (P < 0.05). And the survival rate (95%) in Group 1 was higher than that in Group 2 (81.3%) (P < 0.25); however, hospital stay in Group 1 (44.3 ± 41 d) was shorter than that in Group 2 (55.2 ± 39.5 d) (P < 0.2). So, the prognosis was not improved through the prolongation of time interval for HF, but side-effects were seen.

CONCLUSION: The prognosis was not further improved by LVVH in the treatment of SAP, with side-effects. Time interval for HF plays an important role in treatment of SAP in early stage. SVVH is thought to be superior to LVVH; and LVVH is superior to CVVH in early (72 h) treatment of SAP.