Hemorrhagic Complications of Invasive Intracranial Pressure Monitor Placement in Acute Liver Failure: Outcomes of a Single-Center Protocol and Comprehensive Literature Review

Paediatric acute liver failure: a multidisciplinary perspective on when a critically ill child is unsuitable for liver transplantation

Paediatric acute liver failure is a devastating condition with high morbidity and mortality, which is challenging to manage for the hepatologist, intensivist, and associated specialists. Emergency liver transplantation is required for 10-20% of patients, but for 10% of critically ill children, liver transplantation is deemed unsuitable; the child might be too unwell, or the underlying cause might carry a poor prognosis. Other social, logistical, or ethical considerations are often relevant. Liver transplantation when a patient is too unwell creates perioperative risk to the child that could lead to morbidity, mortality, and potential graft wastage, which is detrimental for others on the waiting list. Donor liver scarcity should prompt an evaluation of whether a transplant is justified through a holistic multidisciplinary lens that considers medical, social, logistical, and ethical concerns. In this Review, we explore, from a multidisciplinary perspective, why a critically unwell child with paediatric acute liver failure might be unsuitable for liver transplantation.

Acute liver failure: Management update and prognosis

Acute liver failure is a rare but serious syndrome, with an incidence of approximately 2,000 to 3,000 cases per year in North America. Its pathophysiology and clinical course vary, depending on the cause of the primary liver injury, and can lead to high morbidity and mortality or the need for liver transplantation, despite available therapies. This syndrome involves excessive activation of the immune system, with damage in other organs, contributing to its high mortality rate. The most accepted definition includes liver injury with hepatic encephalopathy and coagulopathy within the past 26 weeks in a patient with no previous liver disease. The main causes are paracetamol poisoning, viral hepatitis, and drug-induced liver injury, among others. Identifying the cause is crucial, given that it influences prognosis and treatment. Survival has improved with supportive measures, intensive therapy, complication prevention, and the use of medications, such as N-acetylcysteine. Liver transplantation is a curative option for nonresponders to medical treatment, but adequate evaluation of transplantation timing is vital for improving results. Factors such as patient age, underlying cause, and severity of organ failure influence the post-transplant outcomes and survival.

Role of point-of-care ultrasound (POCUS) in clinical hepatology

Hospitalized patients with cirrhosis frequently require critical care management for sepsis, HE, respiratory failure, acute variceal bleeding, acute kidney injury (AKI), shock, and optimization for liver transplantation, while outpatients have unique care considerations. Point-of-care ultrasonography (POCUS) enhances bedside examination of the hepatobiliary system and relevant extrahepatic sites. POCUS includes cardiac US and is used to assess volume status and hemodynamic parameters like cardiac output, systemic vascular resistance, cardiac contractility, and pulmonary artery pressure, which aid in the early and accurate diagnosis of heart failure, cirrhotic cardiomyopathy, porto-pulmonary hypertension, hepatopulmonary syndrome, arrhythmia, and pulmonary embolism. This also helps in fluid management and vasopressor use in the resuscitation of patients with cirrhosis. Lung ultrasound (LUS) can help in differentiating pneumonia, effusion, and edema. Further, US guides interventions such as line placement, drainage of abdominal collections/abscesses, relief of tension pneumothorax, drainage of pleural and pericardial effusions, and biliary drainage in cholangitis. Additionally, its role is essential to assess liver masses foci of sepsis, for appropriate sites for paracentesis, and to assess for vascular disorders such as portal vein or hepatic vein thrombosis. Renal US can identify renal and postrenal causes of AKI and aid in diagnosis of prerenal AKI through volume assessment. In this review, we address the principles and methods of POCUS in hospitalized patients and in outpatients with cirrhosis and discuss the application of this diverse modality in clinical hepatology.

Acute Liver Failure Guidelines

Acute liver failure (ALF) is a rare, acute, potentially reversible condition resulting in severe liver impairment and rapid clinical deterioration in patients without preexisting liver disease. Due to the rarity of this condition, published studies are limited by the use of retrospective or prospective cohorts and lack of randomized controlled trials. Current guidelines represent the suggested approach to the identification, treatment, and management of ALF and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence was reviewed using the Grading of Recommendations, Assessment, Development and Evaluation process to develop recommendations. When no robust evidence was available, expert opinions were summarized using Key Concepts. Considering the variety of clinical presentations of ALF, individualization of care should be applied in specific clinical scenarios.

Intracranial pressure monitoring in the perioperative period of patients with acute liver failure undergoing orthotopic liver transplantation

Acute liver failure (ALF) may result in severe neurological complications caused by cerebral edema and elevated intracranial pressure (ICP). Multiple pathogenic mechanisms explain the elevated ICP, and newer hypotheses have been descri bed. While invasive ICP monitoring (ICPM) may have a role in ALF management, these patients are typically coagulopathic and at risk for intracranial hemorrhage. ICPM is the subject of much debate, and significant heterogeneity exists in clinical practice regarding its use. Contemporary ICPM techniques and coagulopathy reversal strategies may be associated with a lower risk of hemor rhage; however, most of the evidence is limited by its retrospective nature and relatively small sample size.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Transcranial Doppler as a screening test to exclude intracranial hypertension in brain-injured patients: the IMPRESSIT-2 prospective multicenter international study

Background

Alternative noninvasive methods capable of excluding intracranial hypertension through use of transcranial Doppler (ICPtcd) in situations where invasive methods cannot be used or are not available would be useful during the management of acutely brain-injured patients. The objective of this study was to determine whether ICPtcd can be considered a reliable screening test compared to the reference standard method, invasive ICP monitoring (ICPi), in excluding the presence of intracranial hypertension.

Methods

This was a prospective, international, multicenter, unblinded, diagnostic accuracy study comparing the index test (ICPtcd) with a reference standard (ICPi), defined as the best available method for establishing the presence or absence of the condition of interest (i.e., intracranial hypertension). Acute brain-injured patients pertaining to one of four categories: traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH) or ischemic stroke (IS) requiring ICPi monitoring, were enrolled in 16 international intensive care units. ICPi measurements (reference test) were compared to simultaneous ICPtcd measurements (index test) at three different timepoints: before, immediately after and 2 to 3 h following ICPi catheter insertion. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated at three different ICPi thresholds (> 20, > 22 and > 25 mmHg) to assess ICPtcd as a bedside real-practice screening method. A receiver operating characteristic (ROC) curve analysis with the area under the curve (AUC) was used to evaluate the discriminative accuracy and predictive capability of ICPtcd.

Results

Two hundred and sixty-two patients were recruited for final analysis. Intracranial hypertension (> 22 mmHg) occurred in 87 patients (33.2%). The total number of paired comparisons between ICPtcd and ICPi was 687. The NPV was elevated (ICP > 20 mmHg = 91.3%, > 22 mmHg = 95.6%, > 25 mmHg = 98.6%), indicating high discriminant accuracy of ICPtcd in excluding intracranial hypertension. Concordance correlation between ICPtcd and ICPi was 33.3% (95% CI 25.6–40.5%), and Bland–Altman showed a mean bias of -3.3 mmHg. The optimal ICPtcd threshold for ruling out intracranial hypertension was 20.5 mmHg, corresponding to a sensitivity of 70% (95% CI 40.7–92.6%) and a specificity of 72% (95% CI 51.9–94.0%) with an AUC of 76% (95% CI 65.6–85.5%).

Conclusions and relevance

ICPtcd has a high NPV in ruling out intracranial hypertension and may be useful to clinicians in situations where invasive methods cannot be used or not available.

Trial registration: NCT02322970.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03978-2.