Advances in critical care management of hepatic failure and insufficiency

High Volume Plasma Exchange Improves Survival Rates in Surgical Critically Ill Patients With Medical Jaundice and Hepatic Failure: A Comparative Study

OBJECTIVES

Acute liver failure poses a significant challenge in surgical critically ill patients. Treatments typically focus on physiological support and alleviation of hepatic insult. This study aims to evaluate the role of high-volume plasma exchange (HVPE) in surgical critically ill patients with medical jaundice and hepatic failure.

METHOD

A retrospective review was conducted on surgical critically ill patients with hepatic failure unresponsive to conventional therapy, excluding those with obstructive jaundice. HVPE was considered for patients with persistent hyperbilirubinemia (> 10 mg/dL) and coexisting conditions such as coagulopathy, hyperammonemia, more than Grade II hepato-encephalopathy, or exacerbated sepsis/septic shock status or multiple organ failure. Patients were categorized into standard medical treatment (SMT) and SMT + HVPE groups. Demographics and laboratory data were collected for analysis.

RESULT

A total of 117 patients were enrolled, with 79 in the SMT group and 38 in the SMT + HVPE group. There were no significant differences in laboratory data and MELD score upon admission. Before treatment, patients in the SMT + HVPE group exhibited higher levels of T-bil., D-bil., and sugar than the SMT group. After treatment, the SMT + HVPE group showed lower serum D-bil. and AST levels but higher levels of albumin and platelets compared to the SMT group. The SMT + HVPE group demonstrated significantly lower delta T-bil., delta D-bil., and higher delta platelet levels. The survival rate was 31.6% (12/38) in the SMT + HVPE group and 1.3% (1/79) in the SMT group. The in-hospital mortality rate in the SMT + HVPE group was lower than that in the SMT group, with a hazard ratio of 0.42 in the crude model and 0.34 (95% CI = 0.20-0.60 and p = 0.0002) in the adjusted model.

CONCLUSION

Our findings suggest that HVPE improves survival rates in surgical critically ill patients with medical jaundice and hepatic failure. However, due to its retrospective nature, further studies were warranted.

Early Prognostic Predictive System of AECHB and the Diagnosis of Severe Hepatitis B (Liver Failure)

This chapter describes the evaluations for the progression of chronic liver diseases, recent achievement for screening and early warning-parameters of AECHB, diagnosis criteria and grading standards of HBV ACLF.

Several methods have been used to evaluate the progression of chronic liver diseases, including the Child–Turcotte–Pugh (CTP) score, MELD, MESO index, MELD-Na joint formula, iMELD formula, King’s College Hospital (KCH) score, Sequential Organ Failure Assessment (SOFA) score and the Tongji prognostic predictor model (TPPM) score.

Technologies used for early screening of severe hepatitis B include gene-based diagnostic techniques, such as the polymerase chain reaction, gene sequence analysis, gene chips, and GWAS. Protein-based methods include two-dimensional gel electrophoresis and mass spectrometry; and epigenetic-based methods include assays of DNA methylation and histone modifications. In addition, meta-genomics and systematic biology have been used to analyze microbial sequence and function.

Early-warning parameters for severe hepatitis B mainly include serum concentrations of ALT, AST, total bilirubin, albumin and pre-albumin, and cholinesterase; and measurements of blood ammonia, prothrombin time and prothrombin activity. Several new parameters related to severe hepatitis B have been identified, including gene mutations (e.g. HBV 1896 site mutation and 1762/1764 double mutation), genetic molecular targets (e.g. CXCL10-201 g/A, IL10-592 t/C, ESR1 IVS1-401 t/C, TBX21-1993 t/C, and ICAM1 R241-E469), immune factors (e.g. TNF-α, reactive oxygen species, reactive nitrogen species, sCD163, hfgl2, HLA-DR, NK cells, CTL, Th17 cells, Treg cells, PD-1/PD-L), and metabolic factors (e.g. lecithin, fat amides and bile acids).

The clinical diagnosis of severe hepatitis B is mainly based on clinical manifestations, including jaundice, coagulation disorders, hepatic encephalopathy and ascites, and laboratory tests, including prothrombin time, prothrombin activity, international normalized ratio, AST/ALT ratio, and serum concentrations of albumin, bilirubin, cholinesterase, cholesterol, lactic acid, and alpha-fetoprotein.

At present, there are differences among countries in the standard for diagnosing liver failure. In China, liver failure is referred to as severe hepatitis, whereas, in western counties, liver failure caused by viruses is diagnosed as fulminant hepatitis and refers only to acute liver failure. The main difference is that, in China, the concept of acute fulminant hepatitis has been extended to patients without encephalopathy. In contrast, hepatic encephalopathy II is a necessary condition to diagnose severe hepatitis in the United States, Europe and Japan.

Liver failure can be subdivided into acute and chronic liver failure. Acute liver failure includes acute and sub-acute liver failure, and chronic liver failure includes acute-on-chronic and chronic decompensated liver failure. To date, hepatic encephalopathy has been necessary for the diagnosis of acute, but not chronic, liver failure, which is characterized by decompensated liver.

Postoperative Liver Failure

Technical innovations in surgical techniques, anaesthesia, critical care and a spatial understanding of the intra-hepatic anatomy of the liver, have led to an increasing number of liver resections being performed all over the world. However, the number of complications directly attributed to the procedure and leading to inadequate or poor hepatic functional status in the postoperative period remains a matter of concern. There has always been a problem of arriving at a consensus in the definition of the term: postoperative liver failure (PLF). The burgeoning rate of living donor liver transplants, with lives of perfectly healthy donors involved, has mandated a consensual definition, uniform diagnosis and protocol for management of PLF. The absence of a uniform definition has led to poor comparison among various trials. PLF remains a dreaded complication in resection of the liver, with a reported incidence of up to 8 % [1], and mortality rates of up to 30–70 % have been quoted [2]. Several studies have quoted a lower incidence of PLF in eastern countries, but when it occurs the mortality is as high as in the West [3].

Critical Care Basic Ultrasound Learning Goals for American Anesthesiology Critical Care Trainees: Recommendations from an Expert Group

OBJECTIVE

In this review, we define learning goals and recommend competencies concerning focused basic critical care ultrasound (CCUS) for critical care specialists in training.

DESIGN

The narrative review is, and the recommendations contained herein are, sponsored by the Society of Critical Care Anesthesiologists. Our recommendations are based on a structured literature review by an expert panel of anesthesiology intensivists and cardiologists with formal training in ultrasound. Published descriptions of learning and training routines from anesthesia-critical care and other specialties were identified and considered. Sections were written by groups with special expertise, with dissent included in the text.

RESULTS

Learning goals and objectives were identified for achieving competence in the use of CCUS at a specialist level (critical care fellowship training) for diagnosis and monitoring of vital organ dysfunction in the critical care environment. The ultrasound examination was divided into vascular, abdominal, thoracic, and cardiac components. For each component, learning goals and specific skills were presented. Suggestions for teaching and training methods were described.

DISCUSSION

Immediate bedside availability of ultrasound resources can dramatically improve the ability of critical care physicians to care for critically ill patients. Anesthesia--critical care medicine training should have definitive expectations and performance standards for basic CCUS interpretation by anesthesiology--critical care specialists. The learning goals in this review reflect current trends in the multispecialty critical care environment where ultrasound-based diagnostic strategies are already frequently applied. These competencies should be formally taught as part of an established anesthesiology-critical care medicine graduate medical education programs.

Noninvasive surrogates of intracranial pressure: another piece added with magnetic resonance imaging of the cerebrospinal fluid thickness surrounding the optic nerve

Optic nerve sheath diameter enlargement measured by ultrasound is known to be associated with raised intracranial pressure (ICP). Magnetic resonance imaging (MRI) of the cerebrospinal fluid (CSF) surrounding the optic nerve has been found, in an elegant study published in Critical Care, to correlate well with lumbar CSF opening pressure, confirming previously published studies. A simple and rapid T2-weighted fat-suppressed sequence was used to noninvasively measure the CSF width surrounding the optic nerve, allowing one to predict lumbar CSF pressure with relatively good performances, taking into consideration the body mass index and the mean arterial blood pressure. Based on these results and when brain MRI is indicated in situations at risk for increased ICP, the optic CSF thickness measurement could be systematically performed and used as a surrogate marker of raised ICP.

Clinical review: The liver in sepsis

During sepsis, the liver plays a key role. It is implicated in the host response, participating in the clearance of the infectious agents/products. Sepsis also induces liver damage through hemodynamic alterations or through direct or indirect assault on the hepatocytes or through both. Accordingly, liver dysfunction induced by sepsis is recognized as one of the components that contribute to the severity of the disease. Nevertheless, the incidence of liver dysfunction remains imprecise, probably because current diagnostic tools are lacking, notably those that can detect the early liver insult. In this review, we discuss the epidemiology, diagnostic tools, and impact on outcome as well as the pathophysiological aspects, including the cellular events and clinical picture leading to liver dysfunction. Finally, therapeutic considerations with regard to the weakness of the pertinent specific approach are examined.

[Non-invasive evaluation of intracranial pressure: how and for whom?]

The invasive monitoring of intracranial pressure is useful in circumstances associated with high-risk of raised intracranial pressure. However the placement of intracranial probe is not always possible and non-invasive assessment of intracranial pressure may be useful, particularly in case of emergencies. Transcranial Doppler measurements allow the estimation of perfusion pressure with the pulsatility index. Recently, new ultrasonographic methods of cerebral monitoring have been developed: the diameter of the optic nerve sheath diameter, a surrogate marker of raised intracranial pressure and the estimation of median shift line deviation.

Microencapsulated Saccharomyces cerevisiae column bioreactor for potential use in renal failure uremia

A novel bioreactor containing viable APA microencapsulated yeast cells was designed. Rat plasma was used for perfusion. Yeast cell loading and perfusion flow rate were studied to maximize urea removal. An increase in column loading from 25% to 100%, increased urea removal from 5.67 ± 1.34% to 30.45 ± 0.48%. An increase in flow rate from low to high, increased urea removal from 30.46% to 40.4%. At 100% column loading and high flow rate, the creatinine and phosphate concentrations decreased by 22% and 10%, respectively, while ammonia concentrations increased by 58.9% (p < 0.05). Our in-vitro perfusion study demonstrates that microencapsulated yeast cells can remove urea efficiently.

[Sedation and analgesia in intensive care: physiology and application]

Many therapeutic and diagnostic procedures in intensive care medicine are perceived as painful by most patients. As a consequence analgesia and sedation represent two of the main pillars in the treatment of the critically ill. Adaptation to the individual needs of the patients poses one of the biggest challenges that we are confronted with. Both morbidity and mortality can be positively influenced by adequate treatment. In the first part of this review we will discuss the physiology of sleep patterns and pain. Furthermore modes of action and side effects of the most common anesthetics and analgetics will be presented. Finally, the last part of the manuscript deals with the practical application of these therapeutics and their monitoring in intensive care medicine.

Critical care management of patients before liver transplantation

The critical care management of patients before liver transplantation is aimed at optimizing hepatic and extrahepatic organ function before the transplant operation, with a goal to favorably influence perioperative and postoperative graft and patient outcomes. Critical illness in liver disease can present in the context of acute liver failure or acute on chronic liver failure. The differing pathophysiologic processes underlying these 2 types of liver failure necessitate specific approaches to their intensive care management. In their extreme presentations, both types of liver failure present as multiorgan system failure; and therefore, the critical care management of these entities requires a systematic multiorgan system approach to address hepatic and extrahepatic organ dysfunction. This review provides a multiorgan system-based description of critical care management of acute liver failure and acute on chronic liver failure before liver transplantation.

Respiratory failure and hypoxemia in the cirrhotic patient including hepatopulmonary syndrome

PURPOSE OF REVIEW

Liver cirrhosis and portal hypertension present with three unique pulmonary complications that are the subject of ongoing clinical research: hepatopulmonary syndrome, portopulmonary hypertension (POPH), and hepatic hydrothorax. The present article is based on a review of the current literature on how to manage these disorders, which are highly important to both anesthesiologists and intensive care physicians.

RECENT FINDINGS

Hepatopulmonary syndrome leads to progressive hypoxemia through diffuse vasodilatation of the pulmonary microcirculation. Liver transplantation, although associated with increased mortality, is the only viable treatment. POPH occurs when vascular remodeling triggers an increase in pulmonary artery pressure and resistance. The role of liver transplantation in POPH is controversial given the excessive mortality in patients with moderate to severe POPH. Medical treatment is able to decrease pulmonary artery pressures, though multicenter randomized controlled trials showing improved outcome are lacking to date. Ultrasound plays an increasingly important role in the diagnosis of all three conditions.

SUMMARY

Patients with end-stage liver disease are at risk for respiratory failure and hypoxemia and need to be screened for hepatopulmonary syndrome, POPH, and hepatic hydrothorax. Failure to timely recognize and adequately treat these complications of cirrhosis may have severe consequences.

Acetaminophen hepatotoxicity and acute liver failure

Acetaminophen-induced hepatotoxicity is a common consequence of acetaminophen overdose and may lead to acute liver failure (ALF). Currently acetaminophen is the most common cause of ALF in both United States and United Kingdom, with a trend to increasing incidence in the United States. N-acetylcysteine is the most effective drug to prevent progression to liver failure with acetaminophen hepatotoxicity. Liver transplantation is the only definitive therapy that will significantly increase the chances of survival for advanced ALF. This communication reviews current information regarding causes and management of acetaminophen-induced hepatotoxicity and ALF.

Point-of-care continuous 13C-methacetin breath test improves decision making in acute liver disease: Results of a pilot clinical trial

AIM: To assess the role of the ¹³C-methacetin breath test (MBT) in patients with acute liver disease.

METHODS: Fifteen patients with severe acute liver disease from diverse etiologies were followed-up with ¹³C-MBT during the acute phase of their illnesses (range 3-116 d after treatment). Patients fasted for 8 h and ingested 75 mg of methacetin prior to the MBT. We compared results from standard clinical assessment, serum liver enzymes, synthetic function, and breath test scores.

RESULTS: Thirteen patients recovered and two patients died. In patients that recovered, MBT parameters improved in parallel with improvements in lab results. Evidence of consistent improvement began on day 3 for MBT parameters and between days 7 and 9 for blood tests. Later convergence to normality occurred at an average of 9 d for MBT parameters and from 13 to 28 d for blood tests. In both patients that died, MBT parameters remained low despite fluctuating laboratory values.

CONCLUSION: The ¹³C-MBT provides a rapid, non-invasive assessment of liver function in acute severe liver disease of diverse etiologies. The results of this pilot clinical trial suggest that the MBT may offer greater sensitivity than standard clinical tests for managing patients with severe acute liver disease.

Haematological malignancies presenting with acute liver injury: a single-centre experience

INTRODUCTION

Early recognition and identification of the underlying cause of acute liver injury (ALI) is crucial in instituting medical treatment and assessing the need for liver transplantation. Haematological malignancies have been reported to present as ALI with progression to acute liver failure but experience is limited.

AIM

Review our experience of ALI secondary to haematological malignancies.

PATIENTS AND METHODS

Patients admitted to the liver unit with ALI secondary to a haematological malignancy between 1996 and 2006 were identified. A retrospective review was made of their case notes and our database.

RESULTS

Of the 752 cases of ALI, six cases of ALI secondary to haematological malignancy were identified. Common features were a prodromal illness (median duration of 5 weeks; range 2-6 weeks) and jaundice (median bilirubin 208 micromol/l; range 112-238 micromol/l). The majority of patients (5/6) had hepatomegaly. Liver biopsy was performed in two patients and confirmed the diagnosis in both cases. In other cases, the diagnosis was made following lymph node biopsy (1), bone marrow examination (2) or from post-mortem examination (1). Median time from jaundice to encephalopathy was 12 days; range 1-22 days. A single patient underwent liver transplantation but died in the immediate post-operative period. All patients died soon after admission with a median survival of 8 days (range 3-26 days).

CONCLUSION

Haematological malignancy should be considered in ALI patients presenting with a prodromal illness, jaundice and hepatomegaly. Biopsy is essential to confirm the diagnosis but the benefit of definitive therapy such as chemotherapy and/or transplantation in this setting is unclear and survival is poor.

Non-invasive assessment of intracranial pressure using ocular sonography in neurocritical care patients

OBJECTIVE

To assess the relationship between optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in neurocritical care patients.

DESIGN

Prospective, observational study.

SETTING

Surgical critical care unit, level 1 trauma center.

PATIENTS

A total number of 37 adult patients requiring sedation and ICP monitoring after severe traumatic brain injury, subarachnoid hemorrhage, intracranial hematoma, or stroke.

MEASUREMENTS AND MAIN RESULTS

Optic nerve sheath diameter was measured with a 7.5 MHz linear ultrasound probe. ICP was measured invasively via a parenchymal device. Simultaneous measurements were performed at least once a day during the first 2 days after ICP insertion and in cases of acute changes. There was a significant relationship between ONSD and ICP (78 simultaneous measures, r = 0.71, P < 0.0001). Changes in ICP were strongly correlated with changes in ONSD (39 measures, r = 0.73, P < 0.0001). Enlarged ONSD was a suitable predictor of elevated ICP (>20 mmHg) (area under ROC curve = 0.91). When ONSD was less than 5.86 mm, the negative likehood ratio for raised ICP was 0.06.

CONCLUSION

In sedated neurocritical care patients, non-invasive sonographic measurements of ONSD are correlated with invasive ICP, and the probability to have raised ICP if ONSD is less than 5.86 mm is very low. This method could be used as a screening test when raised ICP is suspected.

Preoperative assessment of elderly cancer patients

The incidence of most types of cancers is age-dependent and progressive ageing is rapidly increasing the number of elderly people who need treatment for cancer. It is an ethical dilemma how aggressive one should be when it comes to treating cancer in the older population. Presumed fear of increased postoperative morbidity and mortality often results in delivery of sub-optimal cancer surgery. A careful evaluation of the general and organ-related conditions of the patients is absolutely necessary for planning the right treatment. Nevertheless, preoperative removal of risk factors and postoperative rehabilitation are as important as the use of the best techniques of anaesthesia and surgery to achieve good postoperative outcomes in these patients. In this review article we take into consideration physiology of the aged and tools available to assess surgical risks in elderly patients, in the aim of increasing awareness on optimising surgical management of elderly patients with cancer. MEDLINE and EMBASE.com (search terms: "elderly", "preoperative", "surgery"), bibliographies of articles retrieved and the authors' reference files have been used as data sources. Independent extraction has been performed by the authors using predefined criteria, including study quality indicators.

Incidence and prognosis of early hepatic dysfunction in critically ill patients--a prospective multicenter study

OBJECTIVE

In critically ill patients, hepatic dysfunction is regarded as a late organ failure associated with poor prognosis. We investigated the incidence and prognostic implications of early hepatic dysfunction (serum bilirubin >2 mg/dL within 48 hrs of admission).

DESIGN

Prospective, multicenter cohort study.

SETTING

Thirty-two medical, surgical, and mixed intensive care units.

PATIENTS

A total of 38,036 adult patients admitted consecutively over a period of 4 yrs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Excluding patients with preexisting cirrhosis (n = 691; 1.8%) and acute or acute-on-chronic hepatic failure (n = 108, 0.3%), we identified 4,146 patients (10.9%) with early hepatic dysfunction. These patients had different baseline characteristics, longer median intensive care unit stays (5 vs. 3 days; p < .001) and increased hospital mortality (30.4% vs. 16.4%; p < .001). Hepatic dysfunction was also associated with higher observed-to-expected mortality ratios (1.02 vs. 0.91; p < .001). Multiple logistic regression analysis showed an independent mortality risk of hepatic dysfunction (odds ratio, 1.86; 95% confidence interval, 1.71-2.03; p < .001), which exceeded the impact of all other organ dysfunctions. A case-control study further confirmed these results: Patients with early hepatic dysfunction exhibited significantly increased raw and risk-adjusted mortality compared with control subjects.

CONCLUSIONS

Our results provide strong evidence that early hepatic dysfunction, occurring in 11% of critically ill patients, presents a specific and independent risk factor for poor prognosis.