Changes in intracranial pressure during haemofiltration in oliguric patients with grade IV hepatic encephalopathy

Management of pediatric liver failure with therapeutic plasma exchange and continuous renal replacement therapy: A retrospective observational study

Liver failure represents a critical medical condition, marked by the rapid decline of hepatic functions. Emerging therapies, notably therapeutic plasma exchange (TPE) and continuous venovenous hemodiafiltration (CVVHDF), have demonstrated potential in mitigating these conditions through their roles in detoxification and hepatic support. The utility of these treatments, whether applied individually or in tandem, constitutes a significant area of research concerning the management of liver failure in pediatric patients. This study aims to evaluate the role and efficacy of TPE or TPE combined with CVVHDF in the treatment of liver failure among children. This retrospective study was conducted in a LTICU by reviewing the medical history of pediatric patients aged 1 month to 18 years. Patients were admitted between January 1, 2021 and December 1, 2023 due to acute liver failure or acute-chronic liver failure. The study evaluated those who received TPE or continuous renal replacement therapy combined with TPE. In statistical analyses, a P-value of <.05 was considered statistically significant. The study involved 24 patients with liver failure, comprising 13 males and 11 females. Sixteen patients (66.6%) received only TPE, while 8 patients (33.4%) were treated with TPE and CVVHDF. For patients treated only with TPE, the median INR reduced from 3.1 to 1.26, alanine aminotransferase from 1255 to 148, and aspartate aminotransferase from 2189 to 62. Similar significant reductions were observed in the TPE and CVVHDF group: INR from 3.9 to 1.26, alanine aminotransferase from 1749 to 1148, and aspartate aminotransferase from 1489 to 62. These changes were statistically significant with P-values of .01 for each parameter in both groups. Overall, 14 patients survived without requiring a liver transplant, while 4 patients underwent liver transplantation. Our study on pediatric liver failure treatment shows that both standalone TPE and its combination with CVVHDF are effective, especially as a bridge to transplantation. With 58% transplant-free survival, these therapies demonstrate significant clinical improvements. Future multicentric studies are needed for broader validation of these findings in liver failure management.

Volume Management with Kidney Replacement Therapy in the Critically Ill Patient

While the administration of intravenous fluids remains an important treatment, the negative consequences of subsequent fluid overload have raised questions about when and how clinicians should pursue avenues of fluid removal. Decisions regarding fluid removal during critical illness are complex even for patients with preserved kidney function. This article seeks to apply general concepts of fluid management to the care of patients who also require KRT. Because optimal fluid management for any specific patient is likely to change over the course of critical illness, conceptual models using phases of care have been developed. In this review, we will examine the implications of one such model on the use of ultrafiltration during KRT for volume removal in distributive shock. This will also provide a useful lens to re-examine published data of KRT during critical illness. We will highlight recent prospective trials of KRT as well as recent retrospective studies examining ultrafiltration rate and mortality, review the results, and discuss applications and shortcomings of these studies. We also emphasize that current data and techniques suggest that optimal guidelines will not consist of recommendations for or against absolute fluid removal rates but will instead require the development of dynamic protocols involving frequent cycles of reassessment and adjustment of net fluid removal goals. If optimal fluid management is dynamic, then frequent assessment of fluid responsiveness, fluid toxicity, and tolerance of fluid removal will be needed. Innovations in our ability to assess these parameters may improve our management of ultrafiltration in the future.

Extracorporeal renal and liver support in pediatric acute liver failure

The liver is the only organ which can regenerate and, thus, potentially negate the need for transplantation in acute liver failure (ALF). Cerebral edema and sepsis are leading causes of mortality in ALF. Both water-soluble and protein-bound toxins have been implicated in pathogenesis of various ALF complications. Ammonia is a surrogate marker of water-soluble toxin accumulation in ALF and high levels are associated with higher grades of hepatic encephalopathy, raised intracranial pressure, and mortality. Therefore, extracorporeal therapies aim to lower ammonia and maintain fluid balance and cytokine homeostasis. The most common and easily available modality is continuous kidney replacement therapy (CKRT). Early initiation of high-volume CKRT utilizing an anticoagulation regimen minimizing treatment downtime and delivering the prescribed dose is highly desirable. Ideally, extracorporeal liver-assist devices (ECLAD) should perform both synthetic and detoxification functions of the liver. ECLAD may temporarily replace lost liver function and serve as a bridge, either to spontaneous recovery or liver transplantation. Various bioartificial and biologic liver-assist devices are described in specialty literature, including molecular adsorbent recirculating system (MARS), single pass albumin dialysis (SPAD), and total plasma exchange (TPE); however, clinicians commonly use modalities easily available in intensive care units. There is a lack of standardization of indications for ECLAD, availability of different extracorporeal devices with varied technical approaches, and, of note, the differences in doses of ECLAD provided in clinical practice. We review the practicalities and evidence regarding these four artificial liver support devices in pediatric ALF.

Living Donor Liver Transplant in patients with Hepatorenal Syndrome without the use of Intraoperative Renal Replacement Therapy, a single-center experience

BACKGROUND

Continuous Renal Replacement Therapy (CRRT) is often used to support the intraoperative course during liver transplantation (LT) for patients with HRS. However, the use of intraoperative CRRT (IOCRRT) is not without its problems. Living donor liver transplantation (LDLT) is a planned operation and is possible without IOCRRT as the recipient can be optimized.

AIM

To study the peritransplant outcomes of patients with CLD and HRS undergoing LT without IOCRRT.

METHODS

Analysis of LT program database for perioperative outcomes in patients with HRS from Feb 2017 to Dec 2018.

RESULTS

87/363 (23.9%) adult LDLT patients had HRS, of whom 31 (35.6%) did not respond (NR) to standard medical therapy (SMT) prior to LT. Modified perioperative protocol enabled the NR patients (who were sicker and in persistent renal failure) to undergo LT without IOCRRT. Postoperative renal dysfunction was similar (2 in NR and 2 in R) at 1 year. Post-LT survival was also not different at one month (83.87% in NR and 87.5% in R [p = .640]) and at 1 year (77% in NR vs 80.4% in non-responders [p = .709]).

CONCLUSION

IOCRRT can be avoided in HRS patients undergoing LDLT without compromising their outcomes (post-LT survival and RD), even in patients who have not responded to SMT, preoperatively.

Effect of renal replacement therapy modalities on renal recovery and mortality for acute kidney injury: A PRISMA-compliant systematic review and meta-analysis

Previous investigations showed inconsistent results for comparison in renal recovery, in-hospital, and in-intensive care unit (ICU) mortalities between acute kidney injury (AKI) patients treated with continuous renal replacement therapy (CRRT) and some kinds of intermittent renal replacement therapies (IRRTs). We systematically searched for articles published in the databases (PubMed, Web of Science, EMBASE, Medline, and Google Scholar) until June 2019. We made all statistical analysis using STATA 12.0 software. In the present meta-analysis, relative risks with 95% confidence intervals were calculated for binary outcomes (renal recovery status or mortality). The present study indicated no significant differences in renal recovery, in-hospital mortality, and in-ICU mortality between AKI patients given CRRT and those given sustained low-efficiency dialysis (SLED). Additionally, the study showed no significant difference in in-hospital mortality between AKI patients given CRRT and those given intermittent hemodialysis (IHD), whereas elevated in-ICU mortality was detected in AKI patients given CRRT, compared to those given IHD. The three modalities (CRRT, IHD, and SLED) have their own advantages and disadvantages. More rigorous trials design with large cohort should be made to explore the differences in renal recovery, in-hospital, and in-ICU mortalities between different kinds of RRTs.

Intraoperative continuous renal replacement therapy during liver transplantation: a pilot randomized-controlled trial (INCEPTION)

PURPOSE

To evaluate the feasibility of intraoperative continuous renal replacement therapy (IoCRRT) during liver transplantation (LT), in terms of recruitment, protocol adherence, and ascertainment of follow-up.

METHODS

In this pilot randomized open-label controlled trial in adults receiving LT with a Model for End-Stage Liver Disease (MELD) score ≥ 25 and preoperative acute kidney injury (RIFLE - RISK or higher) and/or estimated glomerular filtration rate < 60 mL·min^-1·1.73 m^-2, patients were randomized to receive IoCRRT or standard of care (SOC). Primary endpoints were feasibility and adverse events. Primary analysis was intention-to-treat (n = 32) and secondary analysis was per-protocol (n = 28).

RESULTS

The trial was stopped early because of slow patient accrual and inadequate funding. Sixty patients were enrolled and 32 (53%) were randomized (n = 15 IoCRRT; n = 17 SOC). Mean (standard deviation) MELD was 36 (8), 81% (n = 26) had cirrhosis; 69% (n = 22) received preoperative RRT; 66% (n = 21) received LT from the intensive care unit. Four patients (n = 2 IoCRRT, n = 2 SOC) did not receive LT post-randomization. Seven patients (41%) allocated to SOC crossed over intraoperatively to IoCRRT. Three patients were lost to follow-up at one year. No adverse events occurred related to IoCRRT. There were no differences in survival at one year (IoCRRT, 71% [n = 10/14] vs SOC, 93% [n = 14/15]; risk ratio, 0.77; 95% confidence interval, 0.54 to 1.1). In the per-protocol analysis (n = 28 received IoCRRT after randomization - n = 20 IoCRRT, n = 8 SOC), one-year survival was 92% and perioperative complications were similar between groups. Only one patient was receiving dialysis one year after LT.

CONCLUSION

In this pilot randomized trial, IoCRRT was feasible and safe with no difference in complications. Crossover rates were high. Despite high preoperative severity of illness, one-year survival was excellent. These data can inform the design of a larger multicentre trial.

TRIAL REGISTRATION

www.clinicalTrials.gov (NCT01575015); registered 12 April, 2012.

Intraoperative Management of a Patient With Impaired Cardiac Function Undergoing Simultaneous ABO-Compatible Liver and ABO-Incompatible Kidney Transplant From 2 Living Donors: A Case Report

BACKGROUND

Combined liver and kidney transplant is a very complex surgery. To date, there has been no report on the intraoperative management of patients with impaired cardiac function undergoing simultaneous ABO-compatible liver and ABO-incompatible kidney transplant from 2 living donors.

CASE REPORT

A 60-year-old man underwent simultaneous ABO-compatible liver and ABO-incompatible kidney transplant from 2 living donors because of IgA nephropathy and alcoholic liver cirrhosis. The preoperative cardiac findings revealed continuous aggravation, shown by large left atrial enlargement, severe left ventricular hypertrophy, a very prolonged QT interval, and a calcified left anterior descending coronary artery. Severe hypotension with very weak pulsation and severe bradycardia developed, with an irregular junctional rhythm noted immediately after the liver graft was reperfused. Although epinephrine was administered as a rescue drug, hemodynamics did not improve, and central venous pressure and mean pulmonary arterial pressure increased to potentially fatal levels. Emergency phlebotomy via the central line was performed. Thereafter, hypotension and bradycardia recovered gradually as the central venous pressure and mean pulmonary arterial pressure decreased. The irregular junctional rhythm returned to a sinus rhythm, but the QTc interval was slightly more prolonged. Because of poor cardiac capacity, the volume and rate of fluid infusion were increased aggressively to maintain appropriate kidney graft perfusion after confirming vigorous urine production of the graft.

CONCLUSIONS

A heart with impaired function due to both end-stage liver and kidney diseases may be less able to withstand surgical stress. Further study on cardiac dysfunction will be helpful for the management of patients undergoing complex transplant surgery.

Systematic review and meta-analysis of renal replacement therapy modalities for acute kidney injury in the intensive care unit

PURPOSE

To compare clinical outcomes among critically ill adults with acute kidney injury (AKI) treated with continuous renal replacement therapy (CRRT), intermittent hemodialysis (IHD) or sustained low efficiency dialysis (SLED).

MATERIALS AND METHODS

We completed a systematic review and meta-analysis of studies published in 2015 or earlier using MEDLINE®, EMBASE®, Cochrane databases and grey literature. Eligible studies included randomized clinical trials (RCTs) or prospective cohort studies comparing outcomes of mortality, dialysis dependence or length of stay among critically ill adults receiving CRRT, IHD or SLED to treat AKI. Mortality and dialysis dependence from RCTs were pooled using meta-analytic techniques. Length of stay from RCTs and results from prospective cohort studies were described qualitatively.

RESULTS

Twenty-one studies were eligible. RRT modality was not associated with in-hospital mortality (CRRT vs IHD: RR 1.00 [95% CI, 0.92-1.09], CRRT vs SLED: RR 1.23 [95% CI, 1.00-1.51]) or dialysis dependence (CRRT vs IHD: RR 0.90 [95% CI, 0.59-1.38], CRRT vs SLED: RR 1.15 [95% CI, 0.67-1.99]).

CONCLUSIONS

We did not find a definitive advantage for any RRT modality on short-term patient or kidney survival. Well-designed, adequately-powered trials are needed to better define the role of RRT modalities for treatment of critically ill patients with AKI.

Clinical Outcomes of Peritoneal Dialysis in End-Stage Renal Disease Patients with Liver Cirrhosis: A Propensity Score Matching Study

Background

Clinical results of long-term peritoneal dialysis (PD) therapy in patients with liver cirrhosis (LC) and end-stage renal disease (ESRD) are controversial. This study evaluated the clinical outcomes of LC patients undergoing PD.

Methods

Clinical records were retrospectively collected from a single center between January 2007 and December 2014. An analysis of PD patients with LC and without liver disease was performed using propensity score matching. We further restricted matching by age, gender, and the presence of diabetes mellitus. Two cohorts of 33 patients each were selected. Early technical complications were defined as the presence of catheter-related complications, including malposition, leakage, omental wrapping, obstruction, and requiring a transfer to hemodialysis (HD) within 6 months of initiating PD.

Results

Mean PD duration was lower in LC patients (57.2 ± 46.1 months) than in controls (85.8 ± 64.2 months). Blood urea nitrogen, creatinine, and albumin levels were significantly lower in LC patients than in the control group. Cystatin C and cystatin C-based glomerular filtration rates were not significantly different in the LC group compared with those in the controls. We found that the risks for early technical complications, peritonitis, and long-term PD and patient survival were not higher in patients with LC than in those without LC. Ascites were easily controlled, and hepatic encephalopathy did not affect PD maintenance in LC patients.

Conclusions

The clinical outcomes, including technical complications, peritonitis, and patients’ survival, suggest that PD can be used as a renal replacement therapy in ESRD patients with LC.

Continuous Renal Replacement Therapy (CRRT) in the Intensive Care Unit

This review is specifically designed to address the topic of CRRT based on the needs and interests of intensivists. Some of the materials, concepts, and formulas presented in this review have been drawn from a previous chapter authored by myself and intended for individuals whose primary interest is specifically dialysis[1]. Since this previous chapter was authored in 1994, similar material presented in this review has been updated in order to present the most current information.

Intraoperative hemodialysis during liver transplantation: a decade of experience

Liver transplantation (LT) for patients with renal dysfunction is frequently complicated by major fluid shifts, acidosis, and electrolyte and coagulation abnormalities. Continuous renal replacement therapy (CRRT) has been previously shown to ameliorate these problems. We describe the safety and clinical outcomes of intraoperative hemodialysis (IOHD) during LT for a group of patients with high Model for End-Stage Liver Disease (MELD) scores. We performed a retrospective study at our institution of patients who underwent IOHD from 2002 to 2012. Seven hundred thirty-seven patients underwent transplantation, and 32% received IOHD. The mean calculated MELD score was 37, with 38% having a MELD score ≥ 40. Preoperatively, 61% were in the intensive care unit, 19% were mechanically ventilated, 43% required vasopressor support, and 80% were on some form of renal replacement therapy at the time of transplantation, the majority being on CRRT. Patients on average received 35 U of blood products and 4.8 L of crystalloids without significant changes in hemodynamics or electrolytes. The average urine output was 450 ml, and the average amount of fluid removal with dialysis was 1.8 L. The 90-day patient and dialysis-free survival rates were 90% and 99%, respectively. One-year patient survival rates based on the pretransplant renal replacement status and the MELD status were not statistically different. This is the first large study to demonstrate the safety and feasibility of IOHD in a cohort of critically ill patients with high MELD scores undergoing LT with good patient and renal outcomes.

Hepatorenal syndrome: the 8th International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group

Introduction

Renal dysfunction is a common complication in patients with end-stage cirrhosis. Since the original publication of the definition and diagnostic criteria for the hepatorenal syndrome (HRS), there have been major advances in our understanding of its pathogenesis. The prognosis of patients with cirrhosis who develop HRS remains poor, with a median survival without liver transplantation of less than six months. However, a number of pharmacological and other therapeutic strategies have now become available which offer the ability to prevent or treat renal dysfunction more effectively in this setting. Accordingly, we sought to review the available evidence, make recommendations and delineate key questions for future studies.

Methods

We undertook a systematic review of the literature using Medline, PubMed and Web of Science, data provided by the Scientific Registry of Transplant Recipients and the bibliographies of key reviews. We determined a list of key questions and convened a two-day consensus conference to develop summary statements via a series of alternating breakout and plenary sessions. In these sessions, we identified supporting evidence and generated recommendations and/or directions for future research.

Results

Of the 30 questions considered, we found inadequate evidence for the majority of questions and our recommendations were mainly based on expert opinion. There was insufficient evidence to grade three questions, but we were able to develop a consensus definition for acute kidney injury in patients with cirrhosis and provide consensus recommendations for future investigations to address key areas of uncertainty.

Conclusions

Despite a paucity of sufficiently powered prospectively randomized trials, we were able to establish an evidence-based appraisal of this field and develop a set of consensus recommendations to standardize care and direct further research for patients with cirrhosis and renal dysfunction.

The challenges of providing renal replacement therapy in decompensated liver cirrhosis

Development of renal failure requiring renal replacement therapy (RRT) in the cirrhotic patient is a devastating complication. Survival without RRT is less than 10% on average at 6 months. However, it is now appreciated that all renal failure in this group of patients is not due solely to hepatorenal syndrome, and the cause of the renal failure affects the prognosis. This paper reviews the prognosis depending on cause and points out the difficulty in making the correct diagnosis. Provision of RRT is difficult in this group of patients due to hypotension and coagulopathy which is highly prevalent. Survival with RRT is still poor with only 30-60% of patients surviving to liver transplant. Provision of RRT should be offered as a bridge to patients awaiting liver transplant or those undergoing liver transplant evaluation. Provision of long-term RRT is usually not indicated in other cirrhotic patients who develop a need for RRT except as a trial to see if renal function will return. The decision between intermittent hemodialysis or continuous renal replacement therapy (CRRT) is usually based on the clinical characteristics of the patient. Neither has been demonstrated to be superior to the other, although CRRT may be better tolerated in the unstable patient. CRRT is clearly indicated in cases of fulminant hepatic failure as it does not raise intracranial pressure. Provision of intraoperative CRRT during liver transplant may be indicated to help control volume and electrolytes in those patients presenting for liver transplant with renal failure. Newer extracorporeal support systems, such as extracorporeal albumin dialysis (MARS) and fractional plasma separation and adsorption with hemodialysis (Prometheus), have recently been developed to provide both renal and liver support in this group of patients. These are still considered experimental, although the MARS system has been utilized to treat patients with hepatorenal syndrome, and is available outside the United States.

Management of hepatic encephalopathy

Hepatic encephalopathy (HE), the neuropsychiatric presentation of liver disease, is associated with high morbidity and mortality. Reduction of plasma ammonia remains the central therapeutic strategy, but there is a need for newer novel therapies. We discuss current evidence supporting the use of interventions for both the general management of chronic HE and that necessary for more acute and advanced disease.

Review article: Renal support in critical illness

PURPOSE

This review provides a focused and comprehensive update on established and emerging evidence in acute renal replacement therapy (RRT) for critically ill patients with acute kidney injury (AKI).

PRINCIPAL FINDINGS

There have been considerable technological innovations in the methods and techniques for provision of extracorporeal RRT in critical illness. These have greatly expanded our capability to provide both renal and non-renal life-sustaining organ support for critically ill patients. Recent data suggest earlier initiation of RRT in AKI may confer an advantage for survival and renal recovery. Two large trials have recently shown no added benefit to augmented RRT dose delivery in AKI. Observational data have also suggested that fluid accumulation in critically ill patients with AKI is associated with worse clinical outcome. However, several fundamental clinical questions remain to be answered, including issues regarding the time to ideally initiate/discontinue RRT, the role of high-volume hemofiltration or other blood purification techniques in sepsis, and extracorporeal support for combined liver-kidney failure. Extracorporeal support with RRT in sepsis, rhabdomyolysis, and liver failure are discussed, along with strategies for drug dosing and management of RRT in sodium disorders.

CONCLUSIONS

We anticipate that this field will continue to expand to promote research and innovation, hopefully for the benefit of sick critically ill patients.

Mathematical Modeling in Cardiac Surgery: Helping Clinical Trials Answer the Question

Mathematical modeling, based on fundamental principles from engineering may help clinical trial design, aiding in answering problems that remain in cardiac surgery, such as management of carotid artery stenosis in patients undergoing cardiopulmonary bypass (CPB), hematocrit during CPB, adequacy of oxygen delivery during CPB, adequacy of blood pressure management during CPB, filtration during bypass for renal failure, bypass circuit pacification, carbon dioxide wound insufflation and neurological events, and pulsatile to nonpulsatile flow during CPB. In addition, mathematical modeling may help explain deficiencies of previous work that have failed to clarify what to do.

Intraoperative renal support during liver transplantation

Acute kidney injury (AKI) is common in liver failure prior to orthotopic liver transplantation (OLT) and may complicate the intraoperative course. We describe the logistics of intraoperative continuous renal replacement therapy (CRRT) during OLT and the associated clinical outcomes. We performed a retrospective review of adult patients (age > 18 years) receiving intraoperative CRRT during OLT at the University of Alberta Hospital between January 1, 1996 and December 31, 2005. Demographic, detailed clinical, and perioperative data, physiologic and laboratory measures, details of renal replacement therapy (RRT) provided, and data on renal recovery and survival were ascertained. Of 636 OLTs, 41 (6.4%) received intraoperative CRRT. The most common indications for OLT in these patients were hepatitis C (34.2%) and alcoholic (29.3%) cirrhosis. The median [interquartile range (IQR)] Model for End-Stage Liver Disease score was 38 (31-43), and 90.2% were classified as Child-Pugh class C. Preoperatively, 70% were in the intensive care unit, 58.5% were mechanically ventilated, and 48.7% required vasopressor support. The median (IQR) duration of intraoperative CRRT was 258 (189-390) minutes, representing 57% of the total operative time. Filter circuit clotting occurred in 40% but was not associated with a shorter CRRT duration (P = 0.41). No other complications were described. CRRT allowed an even or negative intraoperative fluid balance in 92.7%. CRRT was continued in 78% after OLT for a median (IQR) of 5 (3-11) days. Of these, 24 (75%) were transitioned to intermittent hemodialysis for a median (IQR) of 15 (4-39) days. Survival was 97.6% at 1 month and 75.6% at 1 year. Renal recovery to RRT independence occurred in 100% of survivors by 1 year; however, the mean (standard deviation) estimated glomerular filtration rate (eGFR) was 54.7 (19.1) mL/minute/m(2), with 62.1% having an eGFR < 60 mL/minute/m(2). In conclusion, our data suggest that intraoperative CRRT during OLT is achievable and safe. Intraoperative CRRT may be a valuable adjuvant therapy for those with preoperative AKI. Additional investigations are warranted.

Application of intensive care medicine principles in the management of the acute liver failure patient

1. Acute liver failure is a paradigm for multiple system organ failure that develops as a consequence of sepsis. 2. In the United States, systemic inflammatory response, sepsis, and septic shock are common reasons for intensive care unit admission. Intensive care management of these patients serves as a template for the management of patients with acute liver failure. 3. Acute liver failure is attended by high mortality. Although intensive care results in improved survival, the key treatment is liver transplantation. Intensive care unit intervention may open a "window of opportunity" and enable successful liver transplantation in patients who are too ill at presentation. 4. Intracranial hypertension complicates the course for many patients with acute liver failure. Initially, intracranial hypertension results from hyperemia, which is cerebral edema that reduces cerebral blood flow and eventuates in herniation. The precepts of neurocritical care-monitoring cerebral perfusion pressure, cerebral blood flow, and cortical activity-with rapid response to hemodynamic abnormalities, maintenance of normoxia, euglycemia, control of seizures, therapeutic hypothermia, osmotic therapy, and judicious hyperventilation are key to reducing mortality attributable to neurologic failure.

Acute liver failure: a review

Since publication of the first descriptions of acute liver failure (ALF) as a distinct clinical entity in the 1950's, the understanding of the pathophysiologic mechanisms involved and the management options have increased substantially. ALF still represents a major challenge for todays hepatologists, because it can rapidly lead to multiorgan failure and death that may be preventable with appropriate intervention. This article summarizes the basic patho-physiology underlying ALF, compares epidemiologic trends in the United States, the United Kingdom, and the Far East, and reviews prognostic markers and treatment options for ALF.

Artificial and bioartificial support systems for liver failure

BACKGROUND

Artificial and bioartificial liver support systems may 'bridge' patients with acute or acute-on-chronic liver failure to liver transplantation or recovery.

OBJECTIVES

To evaluate beneficial and harmful effects of artificial and bioartificial support systems for acute and acute-on-chronic liver failure.

SEARCH STRATEGY

Trials were identified through The Cochrane Hepato-Biliary Group Controlled Trials Register (September 2002), The Cochrane Central Register of Controlled Trials on The Cochrane Library (Issue 3, 2002), MEDLINE (1966 - September 2002), EMBASE (1985 - September 2002), and The Chinese Biomedical Database (September 2002), manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies.

SELECTION CRITERIA

Randomised clinical trials on artificial or bioartificial support systems for acute or acute on-chronic liver failure were included irrespective of blinding, publication status, or language. Non-randomised studies were included in explorative analyses.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by three reviewers. Results were presented as relative risks (RR) with 95% confidence intervals (CI). Sources of heterogeneity were explored through sensitivity analyses and meta-regression. The primary outcome was mortality.

MAIN RESULTS

Twelve trials on artificial or bioartificial support systems versus standard medical therapy (483 patients) and two trials comparing different artificial support systems (105 patients) were included. Most trials had unclear methodological quality. Compared to standard medical therapy, support systems had no significant effect on mortality (RR 0.86; 95% CI 0.65-1.12) or bridging to liver transplantation (RR 0.87; 95% CI 0.73-1.05), but a significant beneficial effect on hepatic encephalopathy (RR 0.67; 95% CI 0.52-0.86). Meta-regression indicated that the effect of support systems depended on the type of liver failure (P = 0.03). In subgroup analyses, artificial support systems appeared to reduce mortality by 33% in acute-on-chronic liver failure (RR 0.67; 95% CI 0.51-0.90), but not in acute liver failure (RR 0.95; 95% CI 0.71-1.29). Two trials comparing artificial support systems showed significant mortality reductions with intermittent versus continuous haemofiltration (RR 0.58; 95% CI 0.36-0.94) and no significant difference between five versus ten hours of charcoal haemoperfusion (RR 1.03; 95% CI 0.65-1.62). The incidence of adverse events was inconsistently reported.

REVIEWER'S CONCLUSIONS

This Review indicates that artificial support systems may reduce mortality in acute-on-chronic liver failure. Artificial and bioartificial support systems did not appear to affect mortality in acute liver failure. However, considering the strength of the evidence additional randomised clinical trials are needed before any support system can be recommended for routine use.

Artificial and bioartificial support systems for liver failure

BACKGROUND

Artificial and bioartificial liver support systems may 'bridge' patients with acute or acute-on-chronic liver failure to liver transplantation or recovery.

OBJECTIVES

To evaluate beneficial and harmful effects of artificial and bioartificial support systems for acute and acute-on-chronic liver failure.

SEARCH STRATEGY

Trials were identified through The Cochrane Hepato-Biliary Group Controlled Trials Register (September 2002), The Cochrane Central Register of Controlled Trials on The Cochrane Library (Issue 3, 2002), MEDLINE (1966 - September 2002), EMBASE (1985 - September 2002), and The Chinese Biomedical Database (September 2002), manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies.

SELECTION CRITERIA

Randomised clinical trials on artificial or bioartificial support systems for acute or acute on-chronic liver failure were included irrespective of blinding, publication status, or language. Non-randomised studies were included in explorative analyses.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by three reviewers. Results were presented as relative risks (RR) with 95% confidence intervals (CI). Sources of heterogeneity were explored through sensitivity analyses and meta-regression. The primary outcome was mortality.

MAIN RESULTS

Twelve trials on artificial or bioartificial support systems versus standard medical therapy (483 patients) and two trials comparing different artificial support systems (105 patients) were included. Most trials had unclear methodological quality. Compared to standard medical therapy, support systems had no significant effect on mortality (RR 0.86; 95% CI 0.65-1.12) or bridging to liver transplantation (RR 0.87; 95% CI 0.73-1.05), but a significant beneficial effect on hepatic encephalopathy (RR 0.67; 95% CI 0.52-0.86). Meta-regression indicated that the effect of support systems depended on the type of liver failure (P = 0.03). In subgroup analyses, artificial support systems appeared to reduce mortality by 33% in acute-on-chronic liver failure (RR 0.67; 95% CI 0.51-0.90), but not in acute liver failure (RR 0.95; 95% CI 0.71-1.29). Two trials comparing artificial support systems showed significant mortality reductions with intermittent versus continuous haemofiltration (RR 0.58; 95% CI 0.36-0.94) and no significant difference between five versus ten hours of charcoal haemoperfusion (RR 1.03; 95% CI 0.65-1.62). The incidence of adverse events was inconsistently reported.

REVIEWER'S CONCLUSIONS

This Review indicates that artificial support systems may reduce mortality in acute-on-chronic liver failure. Artificial and bioartificial support systems did not appear to affect mortality in acute liver failure. However, considering the strength of the evidence additional randomised clinical trials are needed before any support system can be recommended for routine use.

The first international consensus conference on continuous renal replacement therapy

BACKGROUND

Management of acute renal failure (ARF) in the critically ill is extremely variable and there are no published standards for the provision of renal replacement therapy in this population. We sought to review the available evidence, make evidence-based practice recommendations, and delineate key questions for future study.

METHODS

We undertook an evidence-based review of the literature on continuous renal replacement therapy (CRRT) using MEDLINE searches. We determined a list of key questions and convened a 2-day consensus conference to develop summary statements via a series of alternating breakout and plenary sessions. In these sessions, we identified supporting evidence and generated practice guidelines and/or directions for future research.

RESULTS

Of the 46 questions considered, we found consensus for 20. We found inadequate evidence for 21 questions and for the remaining five we found data but no consensus. Full versions of workgroup findings are available on the Internet at http://www.ADQI.net.

CONCLUSIONS

Despite limited data, broad areas of consensus exist for use of CRRT and guideline development appears feasible. Equally broad areas of disagreement also exist and additional basic and applied research in acute renal failure is needed.

The Acute Dialysis Quality Initiative--part II: patient selection for CRRT

The delivery of optimal acute dialytic support requires that the correct patients be selected for such treatment in a timely fashion and that such treatment be delivered at the appropriate dose, for an appropriate length of time, and for the appropriate indications. The Acute Dialysis Quality Initiative sought to address these issues through an expert-enhanced review of the literature. This article represents a condensation of its findings with regard to patients selection for CRRT, indications for initiation of treatment, transition to other treatments, cessation of treatment, and availability of continuous therapy. The article offers recommendations for clinical practice based on the findings of the expert group. It also offers suggestions and sets priorities for future research in this important area of critical care nephrology.

Outcome of peritoneal dialysis in cirrhotic patients with chronic renal failure

BACKGROUND

Results of peritoneal dialysis (PD) in cirrhotic patients with renal failure are debated. The aim of the present study is to assess the outcome of PD patients with liver cirrhosis.

METHODS

A retrospective study based on clinical records was performed in 21 cirrhotic and 41 PD patients without liver disease followed up at our PD unit.

RESULTS

Five-year patient and technique survival were similar in the two groups. Seven cirrhotic patients (33%) died of liver failure (5 patients), liver cancer (1 patient), and peritonitis (1 patient). Ten controls (24%) died of cardiovascular complications (6 patients), pneumonia (1 patient), cachexia (1 patient), and unknown reasons (2 patients). Six cirrhotic patients discontinued PD therapy after 44.3 +/- 24.7 months because of inadequate dialysis (2 patients), sclerosing peritonitis (2 patients), dementia (1 patient), or patient choice (1 patient). Twelve controls discontinued PD therapy after 33 +/- 25.9 months because of peritonitis (6 patients), exit-site infection (1 patient), inadequate peritoneal clearance (3 patients), catheter malfunction (1 patient), and patient request (1 patient). The peritonitis rate was 0.31 episodes/y in cirrhotic patients and 0.53 episodes/y in controls (P = not significant). The hospitalization rate was similar (16.5 d/y in cirrhotic patients, 15.4 d/y in controls). In cirrhotic patients, complications were leakage (3 patients), symptomatic hypotension (5 patients), anemia (5 patients), severe malnutrition (14 patients), sclerosing peritonitis (2 patients), and hepatic encephalopathy (3 patients).

CONCLUSION

The outcome of PD and risk for bacterial peritonitis or other dialysis complications are not worsened by the presence of liver cirrhosis.

Hepatorenal syndrome. Definition, pathophysiology, and intervention

Hepatorenal syndrome is a well characterized entity in which vasodilation of splanchnic vessels and intense constriction of the renal cortical vasculature occur in concert. The condition is often fatal unless orthotopic liver transplantation (OLT) is performed. Many extracorporeal blood purification techniques exist which can be offered to patients awaiting OLT. Continuous hemofiltration, with or without other modalities such as therapeutic plasma exchange and hemoperfusion, may be helpful in improving the level of consciousness of these patients. Unfortunately, mortality and hepatic regeneration do not appear to be affected by such interventions. The development of a hybrid bioartifical liver support system and pharmacologic manipulation of the hemodynamic perturbations that occur in HRS provide particularly appealing prospects as a means of providing a bridge to liver transplantation in the future.

Usefulness of plasma exchange plus continuous hemodiafiltration to reduce adverse effects associated with plasma exchange in patients with acute liver failure

OBJECTIVE

To efficiently remove middle-molecular-weight substances such as hepatic toxins and minimize adverse effects associated with plasma exchange implementation, we have performed plasma exchange slowly in combination with continuous hemodiafiltration. This study was designed to determine the usefulness of plasma exchange with continuous hemodiafiltration in reducing the adverse effects associated with implementation of plasma exchange alone.

DESIGN

A retrospective clinical study.

SETTING

University teaching hospital.

PATIENTS

The study involved 90 patients with liver failure who had been treated with plasma exchange in our department over the past 12 yrs. We examined these patients by dividing them into two groups (48 patients treated with plasma exchange alone and 42 patients treated with plasma exchange plus continuous hemodiafiltration at the time of plasma exchange implementation).

MEASUREMENTS AND MAIN RESULTS

Baseline blood Na+ concentration, HCO3- concentration, and colloid osmotic pressure were followed after implementation of plasma exchange to compare the frequency of development of three adverse effects (hypernatremia, metabolic alkalosis, and sharp decrease in colloid osmotic pressure) in the two groups. Hypernatremia was found in 26.7% of treatments in the group with plasma exchange alone and 3.3% in the group of plasma exchange plus continuous hemodiafiltration, and metabolic alkalosis was found in 30.6% of treatments in the group with plasma exchange alone and 4.9% in the group of plasma exchange plus continuous hemodiafiltration; both percentages were significantly higher in the group with plasma exchange alone (p <.001). A sharp decrease in colloid osmotic pressure occurred in 13.3% of treatments in the group with plasma exchange alone but was not observed at all in the patients treated with plasma exchange plus continuous hemodiafiltration.

CONCLUSIONS

We conclude that adverse effects associated with plasma exchange for artificial liver support for liver failure can be alleviated with use of plasma exchange plus continuous hemodiafiltration instead of plasma exchange alone.

Acute renal failure associated with liver disease in India: etiology and outcome

Acute renal failure (ARF) associated with liver disease is a commonly encountered clinical problem of varied etiology and high mortality. We have prospectively analyzed patients with liver disease and ARF to determine the etiology, clinical spectrum, prognosis and factors affecting the outcome. Other than hepatorenal syndrome patients, out of 221 cases, 66 developed ARF secondary to various liver disease like cirrhosis (n = 29, mortality 8, risk factors-older age p < 0.01, grade III/IV encephalopathy p < 0.05), fulminant hepatic failure (n = 25, mortality 15, risk factor-prolonged prothrombin time p < 0.01), and obstructive jaundice (n = 12, mortality 7, risk factor-sepsis p < 0.01). In these three groups the factors leading to ARF were volume depletion (24), gastrointestinal bleed (28), sepsis (34), drugs (27) [aminoglycosides (9) and NSAID (18)] along with hyperbilirubinemia. Various types of ARF with contemporaneous liver injury were malaria (n = 37, mortality 15, risk factors-higher bilirubin p < 0.001, higher creatinine p < 0.05, anuria p < 0.05 and dialysis dependency p < 0.05), sepsis (n = 36, mortality 22, risk factors-age p < 0.001, higher bilirubin p < 0.01, oliguria p < 0.05), hypovolemia with ischemic hepatic injury (n = 14, mortality 5, risk factors-higher creatinine p < 0.05 and SGPT p < 0.01), acute pancreatitis (n = 12, mortality 4, risk factors-higher bilirubin p < 0.001, higher SGPT p < 0.01, dialysis dependency p < 0.05), rifampicin toxicity (n = 10, no mortality), paroxysmal nocturnal hemoglobinuria (n = 3, no mortality), CuSO4 poisoning (n = 3 mortality 2), post abortal (n = 11, mortality 6, risk factors higher creatinine p < 0.05 and SGPT p < 0.01), ARF following delivery including HELLP syndrome (n = 12, mortality 4, risk factors-higher bilirubin p < 0.01 and SGPT p < 0.01), and of uncertain etiology (n= 14 mortality 4). 133 patients (60.2%), required hemodialysis hemodialfiltration or peritoneal dialysis. ARF associated with liver disease is having high mortality (42.5%). Avoidance of dehydration, hypotension, nephrotoxic drugs and sepsis, with promote dialytic support are necessary to reduce mortality and morbidity.

Subclinical seizure activity and prophylactic phenytoin infusion in acute liver failure: a controlled clinical trial

Subclinical seizure activity in the patient with encephalopathy and on ventilation with acute liver failure (ALF) is a poorly recognized entity. Its importance lies in the likely exacerbation of cerebral hypoxia and the contribution of such seizure activity to the development of cerebral edema. The aim of the present study was to document the frequency of subclinical seizure activity in a cohort of patients with ALF by using a cerebral function and activity monitor that allows continuous recording of electroencephalogram activity at the bedside and to determine whether the prophylactic administration of the antiepileptic agent phenytoin would reduce its occurrence. Forty-two patients were enrolled in a controlled clinical trial: 20 patients were given phenytoin and 22 acted as controls. Subclinical seizure activity was recorded in 3 and 10 patients, respectively, of the treated and control groups. Pupillary abnormalities indicative of seizure activity and/or raised intracranial pressure (ICP) were also seen less frequently in the phenytoin-treated group compared with the controls (5 and 11 patients, respectively). Autopsy examinations available in 19 patients showed signs of cerebral edema in only 2 (22%) of the phenytoin-treated patients compared with 7 (70%) of the controls (P <.033). Based on these findings, we recommend that patients with ALF, on reaching the stage of grade III or IV encephalopathy, should be routinely monitored for subclinical seizure activity. In this study, prophylaxis with phenytoin reduced the frequency of such seizure activity and its effects, and proved to be safe with the regimen used.

Renal replacement therapies

Slow continuous renal replacement therapy is more hemodynamically stabilizing and is replacing conventional hemodialysis as the therapy of choice for acute renal failure in the intensive care unit. This article presents practical information, including basic terminology, basic physiology, technical aspects, and indications for and application of this technique.

Review article: the management of acute liver failure

Acute liver failure (ALF) is a relatively uncommon but dramatic clinical syndrome with high mortality rates, in which a previously normal liver fails within days or weeks. Paracetamol overdose remains the major cause of ALF in the UK, while viral hepatitis is the commonest cause world-wide. Cerebral oedema is the leading cause of death in patients with ALF. Despite advances in intensive care and the development of new treatment modalities, ALF remains a condition of high mortality best managed in specialist centres. Orthotopic liver transplantation is the only new treatment modality that has made a significant impact in improving outcome. Bioartificial liver support systems and hepatocyte transplantation are new promising treatment options that may change the management of ALF in the future.

Acute continuous hemodiafiltration: a prospective study of 110 patients and a review of the literature

One hundred ten critically ill patients with acute renal failure receiving acute continuous hemodiafiltration (ACHD) in our intensive care unit were studied prospectively. Acute continuous hemodiafiltration consisted either of continuous arteriovenous hemodiafiltration or of continuous veno-venous hemodiafiltration, and was used for 17,817 hours (mean duration of patient treatment, 161.9 hours), resulting in a fall from a mean pre-ACHD urea of 35.7 mmol/L to a plateau value of 16.8 mmol/L at 72 hours of treatment. The mean urea clearance achieved was 24.9 mL/min. Eighty of these patients (72.7%) were receiving artificial ventilation at the time of ACHD and 45 (40.9%) had more than four failing organs. The mean APACHE II score was 27.7. Despite the degree of illness severity, 42 patients (32.2%) survived to discharge from hospital. The use of ACHD was associated with hemodynamic stability, rapid normalization of electrolytes, and the ability to freely administer drugs, blood, and/or blood products. It also allowed for maintenance of an aggressive, nitrogen-rich, nutritional regimen. Support of these critically ill patients with acute renal failure using ACHD was achieved safely and without the employment of additional dialysis-trained nursing staff. Our own experience and a review of the available literature strongly suggest that the advantages associated with the use of ACHD therapies are clinically significant and support the view that ACHD is a modality of renal replacement most suited to critically ill patients with acute renal failure.

Artificial renal and liver support in a severe hepatorenal syndrome of childhood

This case report describes a special management approach in a child aged 4.5 years with a severe form of hepatorenal syndrome in which the final diagnosis was familial hemophagocytic lymphohistiocytosis (FHL). The patient presented with grade IV hepatic coma and acute renal failure (ARF). While the diagnosis was difficult at the time of admission, as well as during acute treatment, artificial liver support was established for elimination of bilirubin and other metabolic by-products by using charcoal column plasma perfusion (CCPP) and bilirubin-adsorbing resin column plasma perfusion (BRCPP). Serum levels of bilirubin showed a notable decrease after each of the four treatment sessions. Additional artificial renal function replacement by continuous arteriovenous hemofiltration and hemodialysis (CAVH, CAVHD, respectively) had a marked lowering effect on urea and creatinine serum concentrations. Both artificial liver and renal support contributed to the general clinical improvement and survival of the patient. Further experience in these therapies will be needed to establish better prognosis in such fatal or acute similar conditions.

Rebound surges of intracranial pressure as a consequence of forced ultrafiltration used to control intracranial pressure in patients with severe hepatorenal failure

Cerebral edema remains the most common immediate cause of death in patients with fulminant hepatic failure. We have used ultrafiltration as a method of controlling intracranial pressure (ICP) when other measures have failed. Two cases in which an initial decrease in ICP was followed by a marked rebound increase resulting in death are reported.