Outcome of children with cerebral edema caused by fulminant hepatic failure

A case report of full recovery from severe cerebral edema secondary to acetaminophen-induced hepatotoxicity in a 13 year old girl

Background

Acetaminophen is a common cause of acute liver failure in pediatrics. Cerebral edema is a significant complication of acute hepatic failure and is associated with increased mortality.

Case presentation

We present a case of a 13 -year old girl with severe cerebral edema secondary to acetaminophen toxicity and hepatic failure. Her poor neurological status precluded her from liver transplantation and withdrawal of life sustaining treatment was recommended. However, with supportive care, she remarkably made a full recovery.

Conclusions

This case highlights the difficulties surrounding prognostication in pediatric patients with cerebral edema from acute liver failure secondary to acetaminophen toxicity.

Pediatric Liver Transplantation: Unique Concerns for the Critical Care Team

Liver transplantation originated in children more than 50 years ago, and these youngest patients, while comprising the minority of liver transplant recipients nationwide, can have some of the best and most rewarding outcomes. The indications for liver transplantation in children are generally more diverse than those seen in adult patients. This diversity in underlying cause of disease brings with it increased complexity for all who care for these patients. Children, still being completely dependent on others for survival, also require a care team that is able and ready to work with parents and family in addition to the patient at the center of the process. In this review, we aim to discuss diagnoses of particular uniqueness or importance to pediatric liver transplantation. We also discuss the evaluation of a pediatric patient for liver transplant, the system for allocating them a new liver, and also touch on postoperative concerns that are unique to the pediatric population.

Visualization of different characteristics of cerebrospinal fluid with acute encephalopathy and febrile seizures using pattern recognition analysis of 1H NMR

BACKGROUND

In acute encephalopathy, deterioration of the condition can be rapid, and early intervention is essential to prevent progression of the disease. However, in the acute period, differentiating acute encephalopathy from febrile seizures is difficult. Thus, an early diagnostic marker has been sought to enable early intervention. Proton nuclear magnetic resonance ((1)H NMR) spectroscopy is used to study the chemical characteristics of biological fluids such as cerebrospinal fluid (CSF). The purpose of this study was to ascertain if pattern recognition of (1)H NMR spectra could differentiate CSF obtained from patients with acute encephalopathy and febrile seizures.

METHODS

CSF was obtained from patients with acute encephalopathy (n = 4), complex febrile seizures (n = 9), and simple febrile seizures (n = 9).

RESULTS

NMR spectra of CSF did not visually differ across the three groups. Spectral data were analyzed by partial least squares discriminant analysis and visualized by plotting the partial least squares scores of each sample. The three patient groups clustered separately on the plots.

CONCLUSION

In this preliminary study, we were able to visualize different characteristics of CSF obtained from patients with acute encephalopathy and simple and complex febrile seizures using pattern recognition analysis of (1)H NMR data.

Molecular Absorbent Recirculating System therapy (MARS®) in pediatric acute liver failure: a single center experience

BACKGROUND

Supportive care as a bridge to transplant or recovery remains challenging in children suffering from acute liver failure (ALF). We report our experience in children using the Molecular Absorbent Recirculating System (MARS(®)).

METHODS

Retrospective data from children receiving therapy using MARS(®) from October 2009 to October 2012 were included in this single-center retrospective study. Patient characteristics, clinical presentation and complications of ALF, clinical and biological data before and after each MARS(®) session, technical modalities and adverse events were recorded.

RESULTS

A total of six children underwent 17 MARS(®) sessions during the study period. Two adolescents were treated with the adult filter MARSFLUX(®) and four infants were treated with the MiniMARS(®) filter. The mean PEdiatric Logistic Dysfunction (PELOD) score at admission was 19 (range 11-33). All patients were mechanically ventilated, and four had acute kidney injury. The neurological course improved in one case, judged as stable in two cases and worsened in one case; data were unavailable in two cases. Mean serum ammonia levels decreased significantly following treatment with MARS(®) from an initial 89 ± 29 to 58 ± 35 mcmol/L (p = 0.02). No other significant biological improvement was observed. Hemodynamic status improved/remained unchanged in the adolescent group, but in the infants four of the seven sessions were poorly tolerated and two sessions were aborted. Three patients died, two were successfully transplanted and one recovered without transplantation.

CONCLUSION

In our experience, treatment with MARS(®) is associated with encouraging results in adolescents, but it needs modification for very sick infants to improve tolerance.

Predictors of outcome in children with acute viral hepatitis and coagulopathy

The presence of coagulopathy in acute viral hepatitis (AVH) in children raises issues about prognosis and need for liver transplantation. We evaluated factors predicting outcome in such patients and determined the applicability of the paediatric acute liver failure study group (PALFSG) definition of acute liver failure (ALF) of coagulopathy alone in comparison with coagulopathy and encephalopathy. Children with AVH (clinical features, raised transaminases and positive viral serology) with uncorrectable coagulopathy [prothrombin time (PT) > 15 s] with or without hepatic encephalopathy (HE) were enrolled. Comparative analysis was based on (i) outcome: survivors/nonsurvivors and (ii) ALF criteria: group A coagulopathy (PT > 15 s) and encephalopathy and group B coagulopathy (PT > 20 s). We studied 130 children (86 boys, mean age 7.5 ± 4.5 years): 86 recovered and 44 died. Single virus infection was present in 96 (74%), hepatitis A being the commonest (n-69). On multiple stepwise logistic regression analysis, age <3.5 years, serum bilirubin ≥ 16.7 mg/dL, PT ≥ 40.5 s and clinical signs of cerebral oedema were independent predictors of mortality. Mortality increased from 0% with single to 100% with four risk factors. Ninety-seven cases met the PALFSG criteria: group A-79 and group B-18. Group A subjects had higher mortality (55.6%vs 0%) and poorer liver functions (bilirubin 18.1 ± 8.9 vs 13.8 ± 6.9 mg/dL, PT 63.9 ± 35.1 vs 27.2 ± 5.2 s) than group B. PT deteriorated significantly with the appearance and progression of HE. One-third of children with AVH with coagulopathy die without transplantation. Age <3.5 years, bilirubin ≥ 16.7 mg/dL, PT ≥ 40.5 s and signs of cerebral oedema are predictors of poor outcome. Children with encephalopathy and coagulopathy have a poorer outcome than those with coagulopathy alone.

Invasive intracranial pressure monitoring is a useful adjunct in the management of severe hepatic encephalopathy associated with pediatric acute liver failure

OBJECTIVE

Pediatric acute liver failure is often accompanied by hepatic encephalopathy, cerebral edema, and raised intracranial pressure. Elevated intracranial pressure can be managed more effectively with intracranial monitoring, but acute-liver-failure-associated coagulopathy is often considered a contraindication for invasive monitoring due to risk for intracranial bleeding. We reviewed our experience with use of early intracranial pressure monitoring in acute liver failure in children listed for liver transplantation.

DESIGN AND PATIENTS

Retrospective review of all intubated pediatric acute liver failure patients with grade III and grade IV encephalopathy requiring intracranial pressure monitoring and evaluated for potential liver transplant who were identified from an institutional liver transplant patient database from 1999 to 2009.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 14 patients were identified who met the inclusion criteria. Their ages ranged from 7 months to 20 yrs. Diagnoses of acute liver failure were infectious (three), drug-induced (seven), autoimmune hepatitis (two), and indeterminate (two). Grade III and IV encephalopathy was seen in ten (71%) and four (29%) patients, respectively. Computed tomography scans before intracranial pressure monitor placement showed cerebral edema in five (35.7%) patients. Before intracranial pressure monitor placement, fresh frozen plasma, vitamin K, and activated recombinant factor VIIa were given to all 14 patients, with significant improvement in coagulopathy (p < .04). The initial intracranial pressure ranged from 5 to 50 cm H2O; the intracranial pressure was significantly higher in patients with cerebral edema by computed tomography (p < .05). Eleven of 14 (78%) patients received hypertonic saline, and three (22%) received mannitol for elevated intracranial pressure. Eight of 14 (56%) monitored patients were managed to liver transplant, with 100% surviving neurologically intact. Four of 14 (28%) patients had spontaneous recovery without liver transplant. Two of 14 (14%) patients died due to multiple organ failure before transplant. One patient had a small 9-mm intracranial hemorrhage but survived after receiving a liver transplant. No patient developed intracranial infection.

CONCLUSIONS

In our series of patients, intracranial pressure monitoring had a low complication rate and was associated with a high survival rate despite severe hepatic encephalopathy and cerebral edema in the setting of pediatric acute liver failure. In our experience, monitoring of intracranial pressure allowed interventions to treat increased intracranial pressure and provided additional information regarding central nervous system injury before liver transplant. Further study is warranted to confirm if monitoring allows more directed intracranial pressure therapy and improves survival in pediatric acute liver failure.

Acute liver failure: Summary of a workshop

Acute liver failure (ALF) is a rare but challenging clinical syndrome with multiple causes; a specific etiology cannot be identified in 15% of adult and 50% of pediatric cases. The course of ALF is variable and the mortality rate is high. Liver transplantation is the only therapy of proven benefit, but the rapidity of progression and the variable course of ALF limit its use. Currently in the United States, spontaneous survival occurs in approximately 45%, liver transplantation in 25%, and death without transplantation in 30% of adults with ALF. Higher rates of spontaneous recovery (56%) and transplantation (31%) with lower rates of death (13%) occur in children. The outcome of ALF varies by etiology, favorable prognoses being found with acetaminophen overdose, hepatitis A, and ischemia (approximately 60% spontaneous survival), and poor prognoses with drug-induced ALF, hepatitis B, and indeterminate cases (approximately 25% spontaneous survival). Excellent intensive care is critical in management of patients with ALF. Nonspecific therapies are of unproven benefit. Future possible therapeutic approaches include N-acetylcysteine, hypothermia, liver assist devices, and hepatocyte transplantation. Advances in stem cell research may allow provision of cells for bioartificial liver support. ALF presents many challenging opportunities in both clinical and basic research.

Cerebrospinal fluid drainage and cranial decompression prolong survival in rats with fulminant hepatic failure

Fulminant hepatic failure (FHF) is a devastating disease. Liver transplantation is the definitive treatment. However, a third of these patients die due to brain edema before a donor becomes available. Cerebrospinal fluid (CSF) drainage and decompressive craniectomy have been used to treat brain edema in brain trauma and hemispheric stroke. However, their role in brain edema associated with FHF has not been examined. In this study we evaluated the potential effects of CSF drainage and decompressive craniectomy on survival in FHF using an experimental model in rats. In CSF drainage experiments all animals had ventriculostomy placed. Five days later FHF was induced with d-galactosamine. Those FHF rats that progressed into comatose stages either received CSF aspiration or did not. In separate experiments the study rats had either a decompressive craniectomy or a sham procedure. FHF was induced 5 days later. We found that both CSF drainage and decompressive craniectomy significantly increased survival of FHF rats compared with the controls: 53.2 +/- 1.1 vs. 48.7 +/- 1.5 h (P = 0.031), and 69.4 +/- 3.9 vs. 53.7 +/- 3.2 h (P = 0.009), respectively. In conclusion, these findings suggest that CSF drainage and decompressive craniectomy may increase the window of opportunity for liver transplantation.

Characterization of acute liver failure and development of a continuous risk of death staging system in children

BACKGROUND/AIMS

Acute liver failure (ALF) in children has been associated with an overall mortality of approximately 70% in the pretransplant era and 50-80% survival in those undergoing orthotopic liver transplantation. There is currently no system for staging severity of ALF in children. The aim of this study was to characterize pediatric ALF in a tertiary hospital and to derive a scoring system to stratify severity of ALF based on predicted mortality.

METHODS

Prospective data collection of 81 children from December 1993-2003 who presented with ALF. Data recorded included peak laboratory values, clinical characteristics, and survival.

RESULTS

Transplant-free survival was 56% with overall survival including those undergoing OLT of 72%. Transplantation rate was 22% with transplant survival of 72%. Of the peak laboratory values analyzed, total bilirubin, prothrombin time/INR, and ammonia were the most predictive of death or a need for liver transplant. A simple risk staging system was developed based on the ability of these three laboratory measurements to predict mortality.

CONCLUSIONS

The survival in pediatric ALF has improved in recent years. Risk staging for ALF could potentially be used in clinical research for risk-adjusted outcomes analysis and to help stratify patients for clinical studies according to mortality risk.

Cytotoxic edema is responsible for raised intracranial pressure in fulminant hepatic failure: in vivo demonstration using diffusion-weighted MRI in human subjects

It is not clear whether cerebral edema in fulminant hepatic failure is predominantly vasogenic or cytotoxic, though cytotoxic edema due to astrocyte swelling is more likely. Diffusion-weighted magnetic resonance imaging can differentiate vasogenic from cytotoxic edema. We performed diffusion-weighted imaging in patients with fulminant hepatic failure to clarify the issue by measuring apparent diffusion coefficient, which quantifies movement of water molecule across cell membrane. Seven patients with fulminant hepatic failure underwent conventional and diffusion-weighted magnetic resonance imaging. Apparent diffusion coefficient was measured in four cortical areas and 12 deep white and gray matter regions in both cerebral hemispheres. Thirteen healthy subjects served as controls. The apparent diffusion coefficient values in patients and controls were compared using Wilcoxon signed rank test. Two patients who survived underwent repeat imaging using same protocol. Patients with FHF had significantly lower apparent diffusion coefficient in all cortical and deep white and gray matter regions of interest compared to controls (p < 0.001), suggesting cytotoxic cell swelling. In two survivors with repeat imaging, one showed complete resolution while the changes persisted in the other, suggesting ischemic injury. Cerebral edema in fulminant hepatic failure is predominantly due to cytotoxic edema.

Liver support for fulminant hepatic failure: is it time to use the molecular adsorbents recycling system in children?

OBJECTIVE

To describe the main liver support devices used for fulminant hepatic failure (FHF) and to review data on the Molecular Adsorbents Recycling System (MARS) and assess its efficiency in children.

DATA SOURCE

Studies were identified through selected readings and a MEDLINE search from 1975 and 2004 using fulminant hepatic failure, acute liver failure, primary graft dysfunction, liver support, MARS, and extracorporeal liver assist device as key words.

STUDY SELECTION

All original studies, including case reports, relating to the use of the MARS or albumin dialysis system were included. Additional attention was put on prognosis criteria of FHF severity in children.

DATA EXTRACTION

Study design, numbers and diagnoses of patients, definite or bridging treatment, outcome measures, and complications were extracted and compiled. Results of individual trials were combined on the risk ratio scale.

DATA SYNTHESIS

Nine randomized trials including 354 patients were identified. However, liver support failed to significantly affect mortality when compared with standard medical therapy. Albumin dialysis, and particularly MARS, emerges as an easily applicable technique for temporary liver support. Some well-designed studies have characterized its efficiency in a few indications, such as in intractable pruritus in chronic liver disease, in acute or chronic liver diseases, and in decompensated cirrhosis with hepatorenal syndrome. In adults and children with FHF, anecdotal reports suggest that MARS may stabilize the patient. However, no randomized controlled study has validated its use in this indication. A randomized controlled study is ongoing in adults with FHF. Such a trial seems to be unfeasible in children for several methodologic reasons.

CONCLUSIONS

Although promising preliminary results suggest that MARS may have a significant position in the therapeutic arsenal for FHF, no sufficient data exist to justify its use in children. For as long as the results of the ongoing adult trial are not available, the indications of this expensive technique in children with FHF are limited.

Cell column chromatography: a new research tool to quantify cerebral cell volume changes following chemically-induced anoxia/re-oxygenation

OBJECTIVE

The roles of individual types of cerebral cells in contributing to brain edema are undefined. The objective of this study was to determine the role of cerebral cell-column chromatography in quantifying cell volumes of individual cerebral cell lines, under chemically-induced anoxia/re-oxygenation (A/R).

METHODS

Cerebral endothelial cells (4 experiments) or type II astrocytes (4 experiments) were cultured to confluence on microcarrier beads. A chromatographic cell-column of 1.5 cm height was filled with non-treated cell-covered beads. The column was perfused at 1 ml/min with a balanced perfusate for one hour (Baseline). The perfusate was then switched to that containing 5 mM thioglycolic acid for one hour (Anoxia). Then the column was perfused with the normal perfusate for another two hours (Re-oxygenation). The total free space in the column, reversely reflecting cell volumes, was determined by averaged transit time (TTa) of a non-permeable flow tracer blue dextran. Decreased TTa means that cells swell, and vice versa.

RESULTS

TTa in endothelial cell columns increased with a peak at 60 minutes of re-oxygenation. TTa in astrocyte columns decreased with a nadir at 30 minutes of re-oxygenation.

CONCLUSION

Cell column chromatography can be used to determine the cerebral cell volume changes following chemically-induced anoxia/re-oxygenation.

Successful treatment of a child with fulminant liver failure and coma caused by Amanita phalloides intoxication with albumin dialysis without liver transplantation

FLF is a life-threatening disease. Hepatic coma exerts dramatic impact on patient survival. At present, LTx is the treatment modality of choice that provides significant improvement in outcome of most patients with FLF. Multiple attempts have been made to reduce mortality and improve the patient's condition. One of the new options is AD - MARS. We present the case of a 11-yr-old boy with FLF and hepatic coma who avoided the scheduled LTx because of rapid neurological and biochemical improvement immediately after three MARS sessions.

What is the optimal cerebral perfusion pressure in children suffering from traumatic coma?

Head injury is a major cause of death and disability in children. Despite advances in resuscitation, emergency care, intensive care monitoring, and clinical practices, there are few data demonstrating the predictive value of certain physiological variables regarding outcome in this patient population. Mean arterial blood pressure (MABP), intracranial pressure (ICP), and cerebral perfusion pressure (CPP = MABP − ICP) are routinely monitored in patients in many neurological intensive care units throughout the world, but there is little evidence indicating that advances in care have been matched with corresponding improvements in outcome.

Nonetheless, there is evidence that hypotension immediately following head injury is predictive of early death, and many patients with these features die with clinical signs of brain herniation caused by intracranial hypertension. Furthermore, available data indicate that a minimal and a mean CPP measured during intensive care are good predictors of outcome in survivors, but a target threshold to improve outcome has yet to be defined.

Some medical management strategies can have detrimental effects, and there is now a good case for undertaking a controlled trial of immediate or delayed craniectomy. Independent outcome in children following severe head injury is associated with higher levels of CPP. The ability to tolerate different levels of CPP may be related to age, and therefore any such surgical trial would need a carefully defined protocol so that the potential benefit of such a treatment is maximized.

Successful treatment of refractory cerebral oedema in ecstasy/cocaine-induced fulminant hepatic failure using a new high-efficacy liver detoxification device (FPSA-Prometheus)

Ecstasy-induced fulminant hepatic failure is associated with high mortality. If complicated by cerebral oedema, orthotopic liver transplantation is the only established treatment. We report a case of combined ecstasy/cocaine-induced fulminant hepatic failure presenting with severe rhabdomyolysis, myocardial infarction and multiorgan failure. Transplantation was declined by the transplant surgeons because of a history of intravenous drug abuse. As excessive hyperammonaemia (318 mumol/l) and refractory transtentorial herniation developed, treatment with a new liver detoxification device combining high-flux haemodialysis and adsorption (FPSA-Prometheus) was initiated. Within a few hours of treatment, ammonia levels normalised. Cerebral oedema was greatly reduced by day 4 and hepatic function gradually recovered. Following neurologic rehabilitation for ischaemic sequelae of herniation, the patient was discharged from hospital with only minimal deficits. In conclusion, efficient extracorporeal detoxification may be an option for reversal of hyperammonaemia and refractory cerebral oedema in ecstasy/cocaine-induced acute liver failure.

Liver transplantation for fulminant hepatitis at Stanford University

BACKGROUND

To review the clinical characteristics and outcomes of 26 patients evaluated for liver transplantation for fulminant hepatic failure at Stanford University and Lucile Packard Children's Hospital in an attempt to identify risk factors and prognostic predictors of survival.

METHODS

A retrospective review of the records of 26 consecutive patients who were evaluated for possible liver transplantation for acute liver failure from May 1, 1995, to January 1, 2000. Pretransplant patient demographics and clinical characteristics were collected, and the data were analyzed by univariate and multivariate analysis.

RESULTS

Clinical assessment of encephalopathy did not predict outcome. Patients with abnormal computed tomography (CT) of the brain had a twofold increase in mortality compared with those patients with normal studies (p = 0.03). Patients requiring mechanical ventilation and continuous venovenous hemofiltration (CVVH) also had a poor prognosis.

CONCLUSION

Predictors of poor outcome after fulminant hepatic failure include abnormal CT scan, mechanical ventilation, and requirement for hemofiltration.

High-flow-rate haemodiafiltration as a brain-support therapy proceeding to liver transplantation for hyperacute fulminant hepatic failure

In fulminant hepatic failure (FHF), rapidly progressive cerebral oedema remains the main fatal complication and an obstacle in liver transplantation. A 29-year-old Japanese woman presented with sudden-onset hepatic encephalopathy and jaundice. Hepatic encephalopathy deteriorated within 2 days of the onset of jaundice. She manifested extensory sustained clonus and was responsive only to pain. Diffuse cerebral oedema was noted on brain computerized tomography (CT) scan. Urgent living-donor liver transplantation (LDLT) at the time of admission was abandoned because of deterioration of neurological status and radiologically evident diffuse cerebral oedema. Instead, a high-flow-rate (7.2-9.0 l/h) haemodiafiltration with a high-performance membrane was commenced, combined with plasma exchange. This treatment regimen resulted in a gradual improvement of hepatic encephalopathy and complete disappearance of cerebral oedema within 7 days. Liver regeneration did not occur during this period, as evident by CT scan volumetry and serological tests. LDLT was subsequently performed using the right liver lobe of the patient's brother. Our case suggests that high-flow-rate haemodiafiltration with a high-performance membrane, combined with plasma exchange, could potentially be brain-support therapy for patients with FHF, and may contribute, when combined with liver transplantation, to the improvement of prognosis in hyperacute FHF.

Graft loss after pediatric liver transplantation

OBJECTIVE

To describe the epidemiology and causes of graft loss after pediatric liver transplantation and to identify risk factors.

SUMMARY BACKGROUND DATA

Graft failure after transplantation remains an important problem. It results in patient death or retransplantation, resulting in lower survival rates.

METHODS

A series of 157 transplantations in 120 children was analyzed. Graft loss was categorized as early (within 1 month) and late (after 1 month). Risk factors were identified by analyzing recipient, donor, and transplantation variables.

RESULTS

Kaplan-Meier 1-month and 1-, 3-, and 5-year patient survival rates were 85%, 82%, 77%, and 71%, respectively. Graft survival rates were 71%, 64%, 59%, and 53%, respectively. Seventy-one of 157 grafts (45%) were lost: 18 (25%) by death of patients with functioning grafts and 53 (75%) by graft-related complications. Forty-five grafts (63%) were lost early after transplantation. Main causes of early loss were vascular complications, primary nonfunction, and patient death. Main cause of late graft loss was fibrosis/cirrhosis, mainly as a result of biliary complications or unknown causes. Child-Pugh score, anhepatic phase, and urgent transplantation were risk factors for early loss. Donor age, donor/recipient weight ratio, blood loss, and technical-variant liver grafts were risk factors for late loss.

CONCLUSIONS

To prevent graft loss after pediatric liver transplantation, potential recipients should be referred early so they can be transplanted in an earlier phase of their disease. Technical-variant liver grafts are risk factors for graft survival. The logistics of the operation need to be optimized to minimize the length of the anhepatic phase.

Detection and monitoring of intracranial pressure dysregulation in liver failure by ultrasound

BACKGROUND

Development of elevated intracranial pressure (ICP) in hepatic failure indicates poor prognosis. Its detection by invasive methods poses methodological problems. We applied ultrasound studies of the optic nerves to noninvasively estimated ICP status.

METHODS

A total of 22 pediatric patients with hepatic failure were examined by serial B scan ultrasound and followed up clinically. Outcome was scored as survival or death due to multiorgan failure (MOF) or raised ICP. In 18 patients, transplantations were performed.

RESULTS

Four patients died before transplantation was possible (raised ICP: n=3, MOF: n=1). After OLT there were 10 survivors and 8 patients died (MOF: n=3, raised ICP: n=5). In 10 patients we found optic nerve sheath diameter (ONSD) above normal limits. Eight patients died, mostly because of raised ICP (n=7). Only 2 of the 10 survivors experienced a transient ONSD increase, steadily normalized after transplantation. Preoperatively, normal ONSD was detected in four of seven patients. The outcome of these four cases was clearly superior (three survivors and one MOF) compared with abnormal pre-OLT ultrasound findings (raised ICP: n=3).

CONCLUSION

Patients with poor prognosis related to raised ICP in pediatric liver failure can be identified by ultrasound measurement of ONSD without the disadvantages of invasive procedures. Although the exact intracranial pressure level cannot be deduced from single examinations, ONSD trends can reflect the evolution of ICP in hepatic encephalopathy.

Protein S-100beta: a biochemical marker for increased intracranial pressure in pigs with acute hepatic failure

BACKGROUND

Acute hepatic failure (AHF) may cause encephalopathy. Intracranial pressure (ICP) is frequently monitored to guide therapy, but such monitoring may cause intracerebral haemorrhagic complications. We hypothesize that determination of serum levels of S-100beta, a protein synthesized in astroglial cells, will provide useful clinical information on the presence and extent of intracranial hypertension in AHF.

METHODS

Continuous intraparenchymatous ICP monitoring and serial S-100beta measurements in serum were performed in 11 Norwegian Landrace pigs with surgically induced AHF and in 4 sham-operated controls.

RESULTS

ICP increased hour by hour in the devascularized pigs in parallel with increased serum levels of protein S-100beta. In the sham-operated controls S-100beta was not detectable at any time point.

CONCLUSIONS

Serum levels of S-100beta are increased early in experimental AHF. Determination of protein S-100beta may provide useful information on the presence and extent of intracranial hypertension in AHF.

Acute liver failure

Severe hepatitis A infection is an infrequent but well-recognized cause of acute liver failure that can now be effectively prevented with vaccination against hepatitis A virus. Bromfenac and troglitazone hepatotoxicity as well as various herbal remedies are some of the newly identified causes of acute liver failure. The recently identified transfusion-transmitted virus has been implicated in some cases of idiopathic acute liver failure whereas hepatitis G virus does not appear to be a causative agent. Recognizing, monitoring, and treating patients with life-threatening cerebral edema remain critically important but difficult aspects of the clinical care of acute liver failure. Hypothermia and N-acetylcysteine are promising experimental approaches to cerebral edema but emergency liver transplantation is the only proven means of improving patient survival. Although recent changes in organ allocation may reduce waiting time to transplantation, more reliable and validated markers of liver regeneration and prognosis are needed to triage patients. The potential application and limitations of novel technologies including bioartificial liver devices and auxiliary liver transplantation continue to evolve from pioneering work in animal models and human subjects.