Development of a new bioartificial liver module filled with porcine hepatocytes immobilized on non-woven fabric

We developed a new bioartificial liver module, a non-woven fabric (NWF) module, which was filled with hepatocytes immobilized on non-woven polyester fabric, and compared its efficacy with a suspension culture vessel. Porcine hepatocytes were isolated from whole pig liver, which formed spheroids in a 1L suspension culture vessel. Some of these spheroids were allowed to construct a 50 mL NWF module by inoculation onto 12 sheets of disk-shaped non-woven fabric then stuffed into a 50 mL column. The remaining spheroids were transferred to a 100 mL spinner flask and placed in suspension. The 50 mL NWF module maintained a much better metabolic and synthetic function than the 100 mL suspension culture vessel throughout the study. Based on these results, we developed a 200 mL radial-flow-type NWF module. This module filled with single hepatocytes showed promising efficiency.

Treatment of hepatic failure--1996: current concepts and progress toward liver dialysis

Liver failure, especially in its acute form, is a medical emergency that quickly leads to failure of multiple other organs. Many of these end-organ failures can be supported temporarily by drugs or medical devices, but the support is invariably short-lived if liver function is not restored. In most instances, liver function can only be restored by transplantation, although patients with acute disease have the potential to recover by regeneration ("spontaneous recovery"). Unfortunately, spontaneous recovery from acute liver failure is uncommon, so the two most important aspects of patient management are highly skilled intensive care and early recognition of patients in need of liver transplantation. Even under these circumstances, the mortality of liver failure remains high because we have no easy way of replacing liver function on demand and donor organs are becoming increasingly difficult to obtain in time. The development of techniques for liver assist offer the possibility that patients with liver failure will become a simple management problem, analogous to the options available in the treatment of acute and chronic renal failure.

Effect of ELAD liver support on plasma HGF and TGF-beta 1 in acute liver failure

The aim of this study was to investigate the effects of treatment with the extracorporeal liver assist device (ELAD) in patients with acute liver failure (ALF) on plasma hepatocyte growth factor (HGF), the most potent growth factor, and transforming growth factor-beta 1 (TGF-beta 1), an inhibitory factor for liver regeneration. Initial plasma HGF, measured by ELISA, was significantly increased in the ALF patients (7.86 +/- SEM 1.76 ng/ml) compared with normal subjects (0.10 +/- 0.02 ng/ml, p < 0.001). After 6 hours of ELAD haemoperfusion, plasma HGF increased further (30.5 +/- 6.19 ng/ml, p < 0.001), with a subsequent decrease towards the initial value by 48 hours. Initial plasma levels of TGF-beta 1 determined by ELISA were significantly increased in the ALF patients (43.4 +/- 5.9 ng/ml) compared with normal subjects (25.1 +/- 2.3 ng/ml, p < 0.01), but there was no change in plasma TGF-beta 1 during the study period in either the ELAD or control ALF group. As HGF is a heparin-binding growth factor and similar changes in HGF were observed during CVVHD, one possible explanation is that heparin administered as anticoagulant for extracorporeal circulation is involved in the effects observed on HGF.

Functional stability of porcine hepatocyte spheroids in various culture systems under 100% porcine and human plasma conditions

To select an immobilization method suitable for bioartificial liver (BAL) modules utilizing porcine hepatocyte spheroids, functional activities were compared in various systems in 100% porcine and human plasma together with a synthesized medium. The spheroids, continuously suspended in rotating dishes or entrapped in collagen (CN) gel, expressed approximately two times higher ammonium detoxification abilities over conventional monolayers during 8 days of direct contact with 100% human or porcine plasma with a standardized inoculum cell number. No significant deterioration was observed in the abilities as compared with that in a synthesized medium. Although the cell number gradually decreased in rotational culture, the abilities per cells remaining on Day 10 were two times higher than in the CN-gel entrapped spheroids in all the media examined, presumably due to the diffusion limitation by the gel. Thus, in utilizing porcine hepatocyte spheroids in BAL modules, immobilization allowing direct contact of spheroids with perfused patient plasma was concluded to be possible and suitable.

Mass transfer limitations to the performance of membrane bioartificial liver support devices

A number of membrane bioartificial devices have been proposed for liver support. However, their design does not yet ensure the successful treatment of acute liver insufficiency. In this paper, the Author reviews the limitations of the mass transport phenomena to the performance of a membrane bioartificial liver support device. First of all the requirements that an optimal membrane bioartificial liver support device has to meet for the therapy to be effective are presented. On these grounds, the issues that are still to be addressed to optimize the performance of such devices are discussed: particular attention is devoted to the mass transport phenomena in each region of the membrane bioartificial device. Finally, the main transport features of the membrane bioartificial liver support devices proposed so far are illustrated and examined.

Budd-Chiari syndrome: technical, hemodynamic, and clinical results of treatment with transjugular intrahepatic portosystemic shunt

PURPOSE

To evaluate use of the transjugular intrahepatic portosystemic shunt (TIPS) as a nonsurgical approach for the management of Budd-Chiari syndrome (BCS).

MATERIALS AND METHODS

Twelve patients with fulminant (n = 2), subacute (n = 5), or chronic (n = 5) BCS underwent TIPS placement. Hepatic venous obstruction was demonstrated at computed tomography and color duplex sonography. BCS was confirmed histologically in all patients. Hemodynamic parameters and clinical characteristics were assessed.

RESULTS

TIPS creation was successful in all patients. Treatment reduced the portal venous pressure gradient by 75% and resulted in a mean shunt flow of 2,300 mL/min +/- 650 (standard deviation). No serious procedure-related complications were observed. The two patients with fulminant BCS died of septicemia or progressive liver failure despite intervention. The other 10 patients showed clinical improvement with reduction or disappearance of ascites. During follow-up, shunt dysfunction occurred in five of 10 patients with recurrence of ascites requiring repeat intervention.

CONCLUSION

TIPS placement is safe and effective in patients with portal hypertension caused by subacute or chronic BCS.

Massive lower extremity arterial thrombosis and acute hepatic insufficiency in a young adult with premature atherosclerosis associated with hyperlipoprotein(a)emia and antiphospholipid syndrome. A case report

The authors describe a healthy young male smoker with familial history of recurrent thromboembolism who presented with severe, rapidly progressive lower limb ischemia and abnormal results from liver function tests. An arteriogram of the lower extremities showed bilateral infrainguinal atherosclerotic arterial occlusions. The laboratory findings, in addition to abnormal liver function findings, included moderately elevated antiphospholipid antibodies and hemostatic abnormalities involving elevated fibrinogen, lipoprotein (a) levels, and deficient fibrinolysis. He underwent bilateral femoral thrombectomy, which was followed by a meticulous anticoagulation, and had gradual improvement of ischemic symptoms and liver functions. This is, to their knowledge, the first reported case in the English literature of premature lower extremity atherosclerosis and antiphospholipid syndrome associated with elevated lipoprotein (a) levels and documented complex hemostatic abnormalities contributing to systemic thrombosis.

Primary or established liver cells for a hybrid liver? Comparison of metabolic features

It is currently in discussion whether or not established liver cell lines can be used for an extracorporeal liver assist device. Thus, metabolic features of primary hepatocytes, immortalized hepatocytes, and hepatoma cells were compared. The ability of these cells to process toxic blood of patients with hepatic failure was investigated by testing their viability in toxin enriched medium that was obtained by toxin separation from patients' blood via a molecular adsorbents recirculating system (MARS). In addition, glucose metabolism, urea synthesis, P450 dependent verapamil metabolism using high performance liquid chromatography, and interleukin-6 induced "acute phase" reaction by sulfodesoxysalicylic acid-polyacrylamide gel electrophoresis detected changes of albumin synthesis were determined in primary hepatocytes and in established liver cells. The viability of hepatoma cells after contact with the toxic compounds coming from the patients' blood was significantly decreased in comparison to that of immortalized hepatocytes and primary hepatocytes. Immortalized hepatocytes and hepatoma cells showed a significantly higher consumption of glucose associated with a significantly higher lactate synthesis. A basic urea synthesis rate could be measured in immortalized hepatocytes and hepatoma cells, but it was significantly lower than that of primary cells. P450 with its subenzyme CYP2C was inducible only in primary hepatocytes and in immortalized cells, but in the latter the enzymatic activity was lower than that of primary cells. The incubation with acute phase mediators resulted in a decrease of albumin synthesis in primary hepatocytes and in hepatoma cells, but it increased the albumin synthesis in immortalized hepatocytes. Summarizing these data, partially beneficial effects can be assumed if established cells are used in an extracorporeal liver assist device. These might include synthesis of some compounds and basic metabolic activities, such as urea synthesis. However, established liver cells showed clearly altered metabolic characteristics. The sufficient removal of toxic compounds requires additional strategies for detoxification by primary hepatocytes in sufficient amounts.

The diagnosis and management of acute liver failure in dogs and cats

Management of the small animal patient with a presumptive diagnosis of acute liver failure should aim to provide high quality supportive care aimed at the functional derangements that occur. A definitive histopathologic diagnosis should be pursued to allow evaluation of the reversibility of the underlying condition. With the current advances in veterinary critical care, improved medical and technical management should reduce both morbidity and mortality in the patient with potentially reversible liver failure.

Plasma separation for artificial liver support

A bioartificial liver (BAL) support system, using plasma separation, has been developed to support acute liver failure patients. This study examined 14 consecutive BAL treatments in nine patients with severe acute liver failure. We report methods to achieve and manage plasma separation for an extended period of time. The mean duration of a BAL treatment was 435 minutes, with 26-59 liters of blood processed. Ionized hypocalcemia resulting in muscle twitching was a side effect of the therapy. Ionized calcium levels decreased significantly (P < .02) after BAL treatment; however, total calcium levels increased (P < .05). No significant changes were noted in heart rate, electrocardiogram [Q-T (Q-Tc) interval], blood pressure, prothrombin time, partial thromboplastin time, hematocrit, platelet count and serum phosphorous, magnesium, glucose, and pH. Plasma fibrinogen levels decreased significantly (P < .002). Ionized hypocalcemia due to the chelating effect of sodium citrate was controlled by calcium chloride administration, adjustment of blood separation rates, and reduction of the blood-to-citrate ratio. This report demonstrates that intensive, large-volume plasma separation for long periods of time can be achieved safely in critically ill patients without serious adverse effects.

Viral causes and management of acute liver failure

Infection with an identified hepatotrophic virus accounts for 13-50% of acute liver failure (ALF) in Europe, and an additional 16-17% of cases have non-A non-B or indeterminate hepatitis in whom a viral aetiology is presumed. Hepatitis C is rarely responsible for acute liver failure in Europe and North America but accounts for a higher proportion of cases in Japan, and hepatitis E may lead to ALF, particularly in pregnant women. The survival in cases of acute liver failure associated with hepatitis A is 70%, whereas less than 30% of those with non-A non-B hepatitis survive without a transplant. Management depends on intensive care support and careful selection of patients likely to benefit from transplantation. Recurrence of hepatitis A and non-A non-B hepatitis has been reported following transplantation for ALF, and hepatitis B recurs less frequently in these circumstances than after transplantation for chronic infection.

[A hemolytic crisis with liver failure as the first manifestation of Wilson's disease]

An 18-year-old woman developed an acute haemolytic anaemia, acute transient renal failure and progressive hepatic failure. Coeruloplasmin and serum copper concentration were normal; a Kayser-Fleischer ring and any neurological symptoms were absent initially. Liver biopsy was contraindicated because of increased bleeding tendency. Wilson's disease was diagnosed only after the acute renal failure had regressed, on the basis of the urinary copper excretion (2890 micrograms/d, rising to 7330 micrograms/d after D-penicillamine administration). Progressive liver failure required transplantation. After it the patient quickly recovered and is now, two years later, free of disease. -This case demonstrates that Wilson's disease may be difficult to diagnose at the time of initial acute manifestation. But it can be recognized early from the pathognomonic low alkaline phosphatase and by calculation of free serum copper.

[Criteria for and results of liver transplantation in patients with acute liver insufficiency]

OBJECTIVE

Evaluation of the results of emergency liver transplantation in patients with acute liver failure.

DESIGN

Analysis of 25 patients with acute liver failure.

SETTING

University Hospital Rotterdam Dijkzigt.

METHOD

Twenty-five patients with acute liver failure were admitted to the Intensive Care Unit in January 1989-May 1993. Patients were selected for emergency liver transplantation according to the Clichy criteria (presence of confusion or coma and factor V activity less than 20-30%).

RESULTS

Liver transplantation was indicated in 17 patients and performed in 13. The 1-year survival rate in patients with a liver transplant was 85%. Four patients with an indication for liver transplantation, but who could not be transplanted died. All 8 patients without an indication for emergency liver transplantation survived.

CONCLUSION

Survival after liver transplantation for acute hepatic failure is now about 80%; the Clichy criteria appear to be helpful in selecting patients with acute hepatic failure for liver transplantation.

Effects of iso and xeno fetal liver fragments transplantation on acute and chronic liver failure in rats

Isogeneic (rat) and xenogeneic (swine) fetal liver fragments (FLF) transplantation into the omentum was performed for D-galactosamine (D-Gal)-induced acute and carbon tetrachloride (CCl4)-induced chronic hepatic failure in rats. The recipients that had iso or xeno FLF showed higher survival rates than the nontransplanted controls on a lethal dose (2.6 g/kg body weight) of D-Gal (survival rates: Iso 70%, Xeno 80%, and control 9.1%). On a sublethal dose (1.0 or 1.2 g/kg) of D-Gal, iso, or xeno FLF caused marked improvement of the values of GPT, GOT, and total bilirubin (T.Bil); at 72 h after D-Gal injection they went significantly lower than those of controls (Iso vs. control; p < 0.01, Xeno vs. control; p < 0.05). Histological examination of the livers revealed severe damage in controls, however, only a slight damage was found in iso or xeno FLF transplanted rats. Iso grafts were fairly well preserved in the omentum at 72 h posttransplants, however, xeno graft had almost changed into a necrotic tissue. CCl4 was administered subcutaneously for 14 wk to induce chronic hepatic failure and then iso FLF were transplanted 3 days after the last CCl4 injection. Iso FLF transplanted rats showed higher improvement of GPT and GOT values at 12 days posttransplants compared with controls (GPT p < 0.01, GOT p < 0.05), although histological improvement was not so remarkable in both group. Iso grafts formed nodules with many hepatocytes in the omentum 12 days posttransplant. The results indicate that iso or xeno FLF transplantation could be an alternative approach for incurable liver insufficiencies.

Combination of plasma exchange and continuous hemofiltration as temporary metabolic support for patients with acute liver failure

The combination of plasma exchange and continuous hemofiltration was applied to patients with acute liver failure, and its clinically advantageous effects were evaluated. This procedure was found to be a powerful approach in decreasing patient morbidity; however, the effect was temporary and the patients finally died. Efforts to eliminate the hepatitis virus, which is the main etiology of hepatic necrosis in Japan, are urgent to salvage patients with fulminant liver failure.

Acute liver failure of unknown pathogenesis: the hidden agenda

A major proportion of sporadic cases of ALF remain of uncertain cause (formerly termed NANB hepatitis). The application of sensitive molecular biology techniques such as PCR indicates that a few cases may be due to cryptic infections with one or more known hepatotropic agents, such as HBV and HCV. Evidence continues to accumulate to incriminate at least one potentially novel and transmissible agent (candidate hepatitis F). In ALF of unknown pathogenesis, survival without transplantation remains less than 20% despite recent improvements in medical management. Close study of recurrent hepatitis after grafting may provide further clues to the possible causes of ALF and the interaction between infectious agent and host. The continued pursuit of potential causes seems justified to allow stratification according to possible pathogeneses. This scientific approach should provide a rational basis for future therapeutic options.

A bioartificial liver to treat severe acute liver failure

OBJECTIVE

To test the safety and efficacy of a bioartificial liver support system in patients with severe acute liver failure.

SUMMARY BACKGROUND DATA

The authors developed a bioartificial liver using porcine hepatocytes. The system was tested in vitro and shown to have differentiated liver functions (cytochrome P450 activity, synthesis of liver-specific proteins, bilirubin synthesis, and conjugation). When tested in vivo in experimental animals with liver failure, it gave substantial metabolic and hemodynamic support.

METHODS

Seven patients with severe acute liver failure received a double lumen catheter in the saphenous vein; blood was removed, plasma was separated and perfused through a cartridge containing 4 to 6 x 10(9) porcine hepatocytes, and plasma and blood cells were reconstituted and reinfused. Each treatment lasted 6 to 7 hours.

RESULTS

All patients tolerated the procedure(s) well, with neurologic improvement, decreased intracranial pressure (23.0 +/- 2.3 to 7.8 +/- 1.7 mm Hg; p < 0.005) associated with an increase in cerebral perfusion pressure, decreased plasma ammonia (163.3 +/- 21.3 to 112.2 +/- 9.8 microMoles/L; p < 0.01), and increased encephalopathy index (0.60 +/- 0.17 to 1.24 +/- 0.22; p < 0.03). All patients survived, had a liver transplant, and were discharged from the hospital.

CONCLUSIONS

This bioartificial liver is safe and serves as an effective "bridge" to liver transplant in some patients.

Plasma exchange and the arterial blood ketone body ratio in patients with acute hepatic failure

Hepatocyte regeneration in acute hepatic failure is essential for recovery, but requires a large amount of energy. One problem with plasma exchange as supportive therapy in these cases is that massive citrate infusion has an adverse effect on the hepatic energy charge, which may be a serious risk in these patients. The ratio of acetoacetate to beta-hydroxybutyrate in arterial blood has been reported to reflect the cellular energy charge of hepatocytes. In this study, this ratio was assessed before and after plasma exchange in 19 patients with acute hepatic failure. Eight patients recovered and 11 died. The arterial blood ketone body ratio was below 0.6 in all 11 nonsurvivors. It fell to below 0.4 in 10 of them during the first plasma exchange session, and remained below 0.4 for over 12 h in seven of them. On the other hand, the arterial blood ketone body ratio returned to above 0.6 in four of eight surviving patients within 12 h after the first plasma exchange and remained below 0.4 for over 12 h only in two of eight patients. These data indicate that plasma exchange may cause suppression of the arterial ketone body ratio in patients with severe acute hepatic failure. These metabolic changes impair liver metabolism and may make effective hepatocyte regeneration impossible.

Acute liver failure

Acute liver failure is a multiorgan syndrome with dramatic clinical features and, often, a fatal outcome. It is characterized by the onset of coma and coagulopathy within 6 months, and usually in < 6 weeks, from onset of illness. Viral hepatitis, drug-related liver injury, and the alcohol-acetaminophen syndrome are the most common etiologies. Altered mental status accompanied by jaundice is a hallmark of acute liver failure. A unique feature is the evolution of increased intracranial pressure due to cerebral edema. The resulting cerebral ischemia and brainstem herniation account for approximately 50% of deaths in patients with acute liver failure. Mannitol therapy may successfully treat most patients with high intracerebral pressure. Most patients demonstrate features of the multiple organ failure syndrome, including a shock-like state, renal failure, and occasionally respiratory distress syndrome. Close monitoring of volume status is necessary, since administration of large quantities of fluid may be required. Infection is also common; most pathogens are gram-positive, and fungal infections are also seen. Because an optimum therapy for acute liver failure does not yet exist, liver transplantation should be considered early, before advanced levels of coma develop. Alternative, experimental treatment modalities include heterotopic liver grafting, administration of hepatocyte growth factor, use of an extracorporeal liver-assist device, and liver cell transplantation, but none of these has attained widespread use.

Significance of pathologic oxygen supply dependency in critically ill patients: comparison between measured and calculated methods

OBJECTIVE

oxygen supply dependency at normal or high oxygen delivery rate has been increasingly proposed as a hallmark and a risk factor in critical illnesses. We hypothesized that as far as an adequate oxygen delivery is provided, oxygen consumption, when determined by indirect calorimetry, is not dependent on oxygen delivery in critically ill patients whereas calculated oxygen consumption is associated with artefactual correlation of oxygen consumption and delivery.

DESIGN

oxygen delivery, oxygen consumption and their relationship were analyzed prospectively. Metabolic data gained from both measured and calculated methods were obtained simultaneously before and after volume loading.

SETTING

the study was completed in the intensive care unit as part of the management protocol of the patients.

PATIENTS

32 consecutive patients entered the study and were divided into 3 groups according to a clinical condition known to favour oxygen supply dependency: sepsis syndrome, adult respiratory distress syndrome and acute primary liver failure.

INTERVENTION

the rise in oxygen delivery was obtained by colloid infusion (oxygen flux test) performed in hemodynamically and metabolically stable patients. All were mechanically ventilated. No change in therapy was allowed during the test.

MEASUREMENTS AND RESULTS

oxygen consumption was simultaneously evaluated by calculation (Fick Principle) and direct measurement using indirect calorimetry. Oxygen delivery was derived from the cardiac output (thermodilution) and arterial content of oxygen. Oxygen supply dependency was considered while observing an increase in oxygen delivery greater than 45 ml/min.m2. Irrespective of patient's clinical diagnosis and outcome, measured oxygen uptake remained unaltered by volume infusion whereas both oxygen delivery and calculated oxygen consumption increased significantly. Arterial lactate level > 2 mmol/l and measured oxygen extraction ratio > 25% failed to identify oxygen supply dependency when measured data were considered.

CONCLUSION

analysis of oxygen uptake, when measured by indirect calorimetry, failed to substantiate oxygen supply dependency in the vast majority of the critically ill patients irrespective of diagnosis and outcome. Mathematical coupling of shared variables accounted for the correlation between oxygen delivery and calculated oxygen consumption.

[Change in the concentration of nontoxic plasma components in the process of hemosorption in experimental acute liver failure]

To study the hemosorption-induced changes in the plasma levels on nontoxic components, experiments were made on dogs with acute hepatic failure simulated by ligation of the common bile and vesicle tracts followed by administration of carbon tetrachloride into the common bile duct. Hemosorption was accomplished by the vein-vein variant by using KAU-type sorbent. Changes in lipid metabolism and the concentrations of biogenic amines were examined during and after a hemosorption session. The positive action of this procedure was found to appear as normalization of lipolysis whose activation occurred in acute hepatic failure, and as increases in the level of histamine and moderate-weight molecules.

Performance of plasma-perfused, microencapsulated hepatocytes: prospects for extracorporeal liver support

The growing success of liver transplantation and the shortage of donor livers has turned attention to the possibility of utilizing hepatocytes within artificial liver support systems to allow time for donor livers to become available and to improve the condition of patients with hepatic failure. This study evaluated encapsulated hepatocytes, a technology which might allow the possibility of using xenogenic or human hepatoma cells. Rabbit hepatocytes were encapsulated using the ionic polysaccharides carboxymethylcellulose, chondroitin sulfate A, chitosan, and polygalacturonic acid. Encapsulated cells were maintained in perfusion culture for at least 6 days in heparinized, normal human plasma or in a defined culture medium. Parallel cultures of plated hepatocytes were also conducted. The metabolic capability of the cells was evaluated by following the rates of urea, albumin, and transferrin synthesis and the transformation rate of the drug antipyrine. Protein synthesis and ureogenesis in plasma were depressed from the levels expressed in defined culture medium. Drug detoxification as measured by antipyrine metabolism appeared to be enhanced in plasma. We conclude that encapsulated rabbit hepatocytes retain significant levels of function for at least 6 days of perfusion with human plasma, suggesting the feasibility of this technology as a potential method of short-term liver support.

Side effects of hybrid liver support therapy: TNF-alpha liberation in pigs, associated with extracorporeal bioreactors

During acute liver failure, hybrid liver support therapy could serve as a bridge to liver transplantation. In this desired temporary use, immune competent cell responses, such as the production of cytokines, might be of limiting relevance. We have investigated the Tumor Necrosis Factor-alpha (TNF) liberation in two models using pigs, connected with an extracorporeal bioreactor with homologous hepatocytes: TNF liberation was measured in arterial plasma during a 4 day perfusion time in untreated animals, model (i), and during short term perfusion of hepatectomized pigs in model (ii). Animals four days after catheter implantation in model (i) had TNF values of < 5 pg/ml. After connecting the system without hepatocytes, TNF rose to 9.7 +/- 2 within 120 min and rose further to 32.6 +/- 6 pg/ml within 4 hours after filling the system with the homologous hepatocytes. After 24 hours of continuous perfusion and during four days of perfusion, the TNF levels were lowered to baseline levels. In model (ii), TNF rose to 220 +/- 130 pg/ml within 180 min and decreased to 110 +/- 10 pg/ml within six hours, whereas controls without hepatocytes showed mean levels with a maximum of 120 +/- 20 pg/ml. In both models, there was no correlation between TNF levels and clinical abnormalities such as fever or shock symptoms. There is evidence for an activation of blood cells during experimental extracorporeal hybrid support. No typical side effects were, however, observed. Thus, TNF mediated extracorporeal cell activation does not appear to limit the application of homologous hybrid liver support therapy.

[The extracorporeal correction of disorders in the blood aggregate state in patients with acute infectious destructions of the lungs and pleura]

Positive hemorheological effect was found in using therapeutical plasmapheresis in combination with extracorporeal blood oxygenation. Indications and contraindications for therapeutical plasmapheresis are discussed in the paper.

[Acute liver failure caused by methylenedioxymethamphetamine ('ecstasy')]

A female aged 18 years who had regularly taken 1-2 tablets of methylenedioxymethamphetamine ('ecstasy') every weekend developed acute liver failure. She recovered after two months hospitalization with conservative treatment. This is the 10th case of hepatotoxicity after use of ecstasy described in the literature. One patient died, another required liver transplantation. In young patients with jaundice and liver dysfunction a side effect of use of ecstasy should be considered as a possible cause.

Improved cardiovascular stability during continuous modes of renal replacement therapy in critically ill patients with acute hepatic and renal failure

OBJECTIVE

To determine whether continuous modes of renal replacement therapy result in improved cardiovascular stability compared with standard daily intermittent treatment in critically ill patients.

DESIGN

Prospective, randomized controlled trial.

SETTING

Intensive care unit in a quaternary referral center for liver failure/transplantation.

PATIENTS

Thirty-two consecutive, critically ill, mechanically ventilated patients with combined acute hepatic and renal failure.

INTERVENTIONS

Patients were randomized to treatment with either intermittent machine hemofiltration or continuous modes of renal replacement therapy; continuous arteriovenous hemofiltration (CAVH) or arteriovenous hemofiltration with dialysis (CAVHD), provided intracranial pressure was controlled.

MEASUREMENTS AND MAIN RESULTS

Cardiac output, tissue oxygen delivery (DO2), and uptake were assessed during 32 treatments with intermittent machine hemofiltration (4 hrs) and during the first 5 hrs of 25 continuous treatments (CAVH and CAVHD). During the first hour of treatment, there was a reduction in cardiac index of 15 +/- 2% during intermittent machine hemofiltration compared with no significant change during the continuous modes of treatment (CAVH/CAVHD) (3 +/- 3%; p < .05). This reduction in cardiac output during intermittent machine hemofiltration was associated with a maximum reduction in mean arterial pressure from 82 +/- 2 to 66 +/- 2 mm Hg (p < .001), a reduction in pulmonary artery occlusion pressure of 27 +/- 4%, tissue DO2 of 15 +/- 3%, and tissue oxygen uptake of 12 +/- 5%, with no significant change in systemic vascular resistance and an increase in pulmonary vascular resistance of 50 +/- 12%. In addition, there was a maximum increase in intracranial pressure of 45 +/- 5% during the first hour of intermittent machine hemofiltration. There were no significant changes during the same time period during the continuous modes of renal replacement therapy.

CONCLUSIONS

In critically ill patients, in whom DO2 is impaired, the use of continuous forms of renal replacement therapy is preferred for its improved cardiovascular tolerance compared with daily intermittent machine treatments.

Cognitive development and learning in the pediatric organ transplant recipient

Although organ transplantation is considered a viable treatment approach for end-stage organ disease, few empirical investigations have assessed the effects of transplantation on the cognitive development and learning of pediatric organ transplant recipients. This article reviews studies evaluating neurocognitive changes following organ transplantation in pediatric end-stage renal and liver disease. Despite numerous methodological problems inherent in the investigations examined, the findings of some studies are suggestive of potential neurocognitive benefits associated with organ transplantation. Recommendations are made regarding methodological improvements for future investigations assessing neurocognitive outcomes of organ transplantation.

[Therapeutic plasmapheresis and extracorporeal low-flow blood oxygenation in the combined treatment of patients with acute suppurative-septic lesions of the lungs and pleura]

It was shown that plasmapheresis included in the complex program of intensive therapy of patients with acute pyo-septic lesions of the lungs and pleura allowed to effectively arrest manifestations of endotoxicosis and to improve results of treatment of this category of patients. Extracorporeal hemoxygenation of small volumes added to plasmapheresis at the expense of inclusion of dialyzer DIP-02-02 in the extracorporeal contour considerably reinforced the detoxicating effect of plasmapheresis at the expense of nonspecific biotransformation of toxins.