Acute Fulminant Hepatic Failure, Encephalopathy and Early CT Changes

Cerebral Edema in Acute Liver Failure: Insights From Autopsy

Acute liver failure (ALF) is a rare critical illness with a high mortality, characterised by the abrupt loss of hepatic function associated with altered consciousness from hepatic encephalopathy. In some patients, the further development of cerebral edema (CE) and intracranial hypertension (ICH) with cerebral herniation (CH) can be fatal. The current prevalence of CE and CH is unknown, and the utility of clinical physical signs and cerebral computed tomography (CT) imaging to assess the presence of CE and ICH has had limited evaluation. We investigated these issues in a large ALF patient series, evaluating cerebral findings at autopsy. The prevalence of CE and CH was markedly lower than previously reported, present in only a minority of cases studied. Younger age, more severe HE, and vasopressor requirement were closely associated with CE and CH, and manifestations were present early after transfer to a transplantation centre. External clinical signs were specific for CE but lacked sensitivity, failing to identify the majority of autopsy-proven cases. Cerebral CT showed high specificity, sensitivity, and accuracy.

Acute Liver Failure Study Group. Brain CT Scan Diagnostic and Prognostic Value in Patients With Acute Liver Failure and Cerebral Edema: A Multicenter Cohort Study

OBJECTIVE

Patients with acute liver failure (ALF) may develop cerebral edema. We aimed to study the CT scan diagnostic and prognostic value among patients with ALF and cerebral edema.

DESIGN

International multicenter retrospective cohort.

SETTING

U.S. Acute Liver Failure Study Group prospective registry.

PATIENTS

Consecutive patients with ALF within the registry from January 1998 to August 2016.

INTERVENTIONS

The primary exposure was cerebral edema on CT scan. The primary endpoint was 21-day post-inclusion transplant-free survival (TFS).

MEASUREMENTS AND MAIN RESULTS

Among 2108 patients with ALF, 243 (11.5%) had a brain CT scan. Among those 243 patients, 105 (43.2%) had cerebral edema and 11 (4.5%) later developed tonsillar herniation. Patients with cerebral edema on CT scan were younger (36 vs. 46 yr; p < 0.001) and more often females (81.0% vs. 63.8%; p = 0.003), had more acetaminophen-related ALF (61.0% vs. 39.4%; p < 0.001), required more frequently invasive mechanical ventilation on day 1 (73.3% vs. 55.8%; p = 0.005), and had higher maximum days 1-7 model for end-stage liver disease (MELD) score (39 vs. 35; p = 0.002) than others. Following adjustment for confounders (age, acetaminophen toxicity, and severity of disease by MELD), cerebral edema was associated with lower odds of 21-day TFS (adjusted odds ratio = 0.36 [95% CI, 0.18-0.72]; C-statistic = 0.81 [95% CI, 0.75-0.86]; p = 0.003). However, cerebral edema was not associated with selection for liver transplant (22.9% vs. 16.1%; p = 0.18).

CONCLUSIONS

In our cohort of patients with ALF, brain CT scan use increased overtime. Among those with a brain CT scan, about two in five had cerebral edema. Cerebral edema on CT scan was independently associated with worse 21-day TFS but did not preclude transplant. Brain CT scan may provide additional diagnostic and prognostic information in selected patients with ALF.

Altered Mental Status in the Solid-Organ Transplant Recipient

Patients undergoing solid-organ transplantation (SOT) face a tumultuous journey. Prior to transplant, their medical course is characterized by organ dysfunction, diminished quality of life, and reliance on organ support, all of which are endured in hopes of reaching the haven of organ transplantation. Peritransplant altered mental status may indicate neurologic insults acquired during transplant and may have long-lasting consequences. Even years after transplant, these patients are at heightened risk for neurologic dysfunction from a myriad of metabolic, toxic, and infectious causes. This review provides a comprehensive examination of causes, diagnostic approaches, neuroimaging findings, and management strategies for altered mental status in SOT recipients. Given their complexity and the numerous etiologies for neurologic dysfunction, liver transplant patients are a chief focus in this review; however, we also review lesser-known contributors to neurological injury across various transplant types. From hepatic encephalopathy to cerebral edema, seizures, and infections, this review highlights the importance of recognizing and managing pre- and posttransplant neurological complications to optimize patient outcomes.

The usefulness of head computed tomography in patients with known cirrhosis presenting to emergency department with suspected hepatic encephalopathy

Background

Computed tomography of the head (CT head) is frequently used for patients with cirrhosis presenting with suspected hepatic encephalopathy (HE).

Aims

The primary aims of this study were to assess the frequency of CT head usage in this patient population and to determine whether these scans yielded significant findings. Our secondary aims were to identify factors associated with the decision to order CTs and whether patients who received CTs had different outcomes.

Methods

A single-centre, retrospective chart review was performed. Patients presenting to the University of Alberta Hospital with cirrhosis and common liver disease aetiologies over a 27-month period were identified via discharge diagnosis codes. Charts of patients with suspected HE were manually identified. The use of a CT head was documented, as were patient demographics, cirrhosis aetiology, MELD, and outcomes. Comparisons were made between patients with and without CT head.

Results

A total of 119 encounters from 100 patients met our inclusion criteria. In 57% of encounters, a CT scan was performed on presentation. None of these CT scans had significant findings. Patient factors associated with the decision to order CT included older age, more preserved liver function, and longer length of time between patient's current and previous presentations. Patients who did not receive CT head had higher in-hospital mortality, which was likely reflective of more severe underlying liver dysfunction in this group.

Conclusions

The frequency of CT head usage in the studied patient population was high while the yield was low. This calls into question the usefulness of CT head in this population.

Brain and the Liver: Cerebral Edema, Hepatic Encephalopathy and Beyond

Occurrence of brain dysfunction is common in both chronic liver disease as well as acute liver failure. While brain dysfunction most commonly manifests as hepatic encephalopathy is chronic liver disease; devastating complications of cerebral edema and brain herniation syndromes may occur with acute liver failure. Ammonia seems to play a central role in the pathogenesis of brain dysfunction in both chronic liver disease and acute liver failure. In this chapter we outline the pathophysiology and clinical management of brain dysfunction in the critically ill patients with liver disease.

Hepatic Encephalopathy-the Old and the New

Hepatic encephalopathy occurs ubiquitously in all causes of advanced liver failure, however, its implications on mortality diverge and vary depending upon acuity and severity of liver failure. This associated mortality has decreased in subsets of liver failure over the last 20 years. Aside from liver transplantation, this improvement is not attributable to a single intervention but likely to a combination of practical advances in critical care management. Misconceptions surrounding many facets of hepatic encephalopathy exists due to heterogeneity in presentation, pathophysiology and outcome. This review is intended to highlight the important concepts, rationales and strategies for managing hepatic encephalopathy.

Emerging strategies for the treatment of patients with acute hepatic failure

PURPOSE OF REVIEW

The objective of this article is to review the latest developments related to the treatment of patients with acute liver failure (ALF).

RECENT FINDINGS

As the treatment of ALF has evolved, there is an increasing recognition regarding the risk of intracranial hypertension related to advanced hepatic encephalopathy. Therefore, there is an enhanced emphasis on neuromonitoring and therapies targeting intracranial hypertension. Also, new evidence implicates systemic proinflammatory cytokines as an etiology for the development of multiorgan system dysfunction in ALF; the recent finding of a survival benefit in ALF with high-volume plasmapheresis further supports this theory.

SUMMARY

Advances in the critical care management of ALF have translated to a substantial decrease in mortality related to this disease process. The extrapolation of therapies from general neurocritical care to the treatment of ALF-induced intracranial hypertension has resulted in improved neurologic outcomes. In addition, recognition of the systemic inflammatory response and multiorgan dysfunction in ALF has guided current treatment recommendations, and will provide avenues for future research endeavors. With respect to extracorporeal liver support systems, further randomized studies are required to assess their efficacy in ALF, with attention to nonsurvival end points such as bridging to liver transplantation.

23.4% Saline Decreases Brain Tissue Volume in Severe Hepatic Encephalopathy as Assessed by a Quantitative CT Marker

OBJECTIVE

Cerebral edema is common in severe hepatic encephalopathy and may be life threatening. Bolus 23.4% hypertonic saline improves surveillance neuromonitoring scores, although its mechanism of action is not clearly established. We investigated the hypothesis that bolus hypertonic saline decreases cerebral edema in severe hepatic encephalopathy utilizing a quantitative technique to measure brain and cerebrospinal fluid volume changes.

DESIGN

Retrospective analysis of serial CT scans, and clinical data for a case-control series were performed.

SETTING

ICUs of a tertiary care hospital.

PATIENTS

Patients with severe hepatic encephalopathy treated with 23.4% hypertonic saline and control patients who did not receive 23.4% hypertonic saline.

INTERVENTIONS

23.4% hypertonic saline bolus administration.

MEASUREMENTS AND MAIN RESULTS

We used clinically obtained CT scans to measure volumes of the ventricles, intracranial cerebrospinal fluid, and brain using a previously validated semiautomated technique (Analyze Direct, Overland Park, KS). Volumes before and after 23.4% hypertonic saline were compared with Wilcoxon signed rank test. Associations among total cerebrospinal fluid volume, ventricular volume, serum sodium, and Glasgow Coma Scale scores were assessed using Spearman rank correlation test. Eleven patients with 18 administrations of 23.4% hypertonic saline met inclusion criteria. Total cerebrospinal fluid (median, 47.6 mL [35.1-69.4 mL] to 61.9 mL [47.7-87.0 mL]; p < 0.001) and ventricular volumes (median, 8.0 mL [6.9-9.5 mL] to 9.2 mL [7.8-11.9 mL]; p = 0.002) increased and Glasgow Coma Scale scores improved (median, 4 [3-6] to 7 [6-9]; p = 0.008) after 23.4% hypertonic saline. In contrast, total cerebrospinal fluid and ventricular volumes decreased in untreated control patients. Serum sodium increase was associated with increase in total cerebrospinal fluid volume (r = 0.83, p < 0.001), and change in total cerebrospinal fluid volume was associated with ventricular volume change (r = 0.86; p < 0.001).

CONCLUSIONS

Total cerebrospinal fluid and ventricular volumes increased after 23.4% hypertonic saline, consistent with a reduction in brain tissue volume. Total cerebrospinal fluid and ventricular volume change may be useful quantitative measures to assess cerebral edema in severe hepatic encephalopathy.