Contributing factors and outcomes of burn-associated cholestasis

Effect of quality nursing intervention on wound healing in patients with burns: A meta-analysis

This meta-analysis aimed to explore the effects of quality nursing intervention on wound healing in patients with burns. A computerised search was conducted for randomised controlled trials (RCTs) on the effect of quality nursing intervention on wound healing in patients with burns in the PubMed, Embase, Google Scholar, Cochrane Library, China National Knowledge Infrastructure and Wanfang databases from the date of database inception to November 2023. Two researchers independently screened the literature, extracted data and performed quality assessment based on the inclusion and exclusion criteria. Stata 17.0 software was used for the data analysis. Twenty-nine RCTs involving 2637 patients with burns were included. The meta-analysis revealed that compared with conventional nursing, the implementation of quality nursing intervention in patients with burns significantly shortened the wound healing time (standardised mean difference [SMD] = -2.93, 95% confidence interval [CI]: -3.44 to -2.42, p < 0.001). The incidence of wound infections (odds ratio [OR] = 0.14, 95% CI: 0.07-0.27, p < 0.001) and complications (OR = 0.16, 95% CI: 0.11-0.23, p < 0.001) was also reduced significantly. This meta-analysis shows that applying quality nursing interventions in patients with burns can significantly shorten the wound healing time and reduce the incidence of wound infection and complications, thus promoting early patient recovery.

Ketamine restriction correlates with reduced cholestatic liver injury and improved outcomes in critically ill patients with burn injury

Background & Aims

Ketamine-associated cholestatic liver injury is reported in patients with severe burn injury, but its association with patient outcome is unclear. We investigated the relationship between ketamine exposure, cholestatic liver injury, and outcome of critically ill patients with burn injury.

Methods

In a retrospective study, patients with severe burn injury were analysed across two periods: unrestricted ketamine prescription (ketamine-liberal) and capped ketamine dosage (ketamine-restricted). The primary endpoint was cholestatic liver injury, and the secondary endpoint was 3-month mortality. Binary logistic regression models and the revised electronic causality assessment method were used to measure the strength of associations and causality assessment, respectively.

Results

Of 279 patients (median age 51 [IQR 31-67] years; 63.1% men; burned surface area 28.5%, IQR 20-45%), 155 (56%) were in the ketamine-liberal group, and 124 (44%) were in the ketamine-restricted group, with comparable clinical characteristics, except for ketamine exposure (median doses 265.0 [IQR 0-8,021] mg and 20 [IQR 0-105] mg, respectively; p <0.001). A dose- and time-dependent relationship was observed between ketamine exposure and cholestatic liver injury. Ketamine restriction was associated with a reduced risk of cholestatic liver injury (adjusted odds ratio 0.16, 95% CI 0.04-0.50; p = 0.003) and with a higher probability of 3-month survival (p = 0.035). The revised electronic causality assessment method indicated that ketamine was probably and possibly the cause of cholestatic liver injury for 14 and 10 patients, respectively. Cholangitis was not observed in the ketamine-restricted group. In propensity-matched patients, the risk of 3-month mortality was higher (adjusted odds ratio 9.92, 95% CI 2.76-39.05; p = 0.001) in patients with cholestatic liver injury and ketamine exposure ≥10,000 mg. Other sedative drugs were not associated with liver and patient outcome.

Conclusions

In this cohort, ketamine restriction was associated with less cholestatic liver injury and reduced 3-month mortality.

Impact and implications

In a cohort of 279 critically ill patients with burn injury, ketamine was associated with a risk of liver bile duct toxicity. The risk was found to be dependent on both the dosage and duration of ketamine use. A restriction policy of ketamine prescription was associated with a risk reduction of liver injury and 3-month mortality. These findings have implications for the analgesia and sedation of critically ill patients with ketamine, with higher doses raising safety concerns.

Burn-Induced Apoptosis in the Livers of Aged Mice Is Associated With Caspase Cleavage of Bcl-xL

INTRODUCTION

Older adult burn victims have poorer outcomes than younger burn victims. The liver is critical for the recovery of patients with burns. Postburn hepatic apoptosis in young individuals compromises liver integrity; however, this pathway has not yet been studied in older individuals. Because aged animals with burns suffer significant liver damage, we hypothesized that apoptosis is altered in these animals and may affect liver function. Understanding postburn hepatic apoptosis and its effects on liver function in aged animals may help improve outcomes in older patients.

METHODS

We compared the protein and gene expression levels in young and aged mice after a 15% total-body-surface-area burn. Liver and serum samples were collected at different time points after injury.

RESULTS

Caspase-9 expression in liver tissue was downregulated by 47% in young animals and upregulated by 62% in aged animals 9 h postburn (P < 0.05). The livers of aged mice showed a Bcl-extra-large (Bcl-xL) transcription increase only after 6 h; however, the livers of young mice exhibited 4.3-fold, 14.4-fold, and 7.8-fold Bcl-xL transcription increases at 3, 6, and 9 h postburn, respectively (P < 0.05). The livers of young mice showed no changes in Caspase-9, Caspase-3, or Bcl-xL protein levels during the early postburn period. In contrast, the livers of aged mice contained cleaved caspase-9, reduced full-length caspase-3, and an accumulation of ΔN-Bcl-x at 6 and 9 h postburn (P < 0.05). p21 expression decreased in aged mice; however, it was significantly increased in the liver tissue of young mice postburn (P < 0.05). Serum amyloid A1 and serum amyloid A2 serum protein levels were 5.2- and 3.1-fold higher in young mice than in aged mice, respectively, at 6 and 9 h postburn (P < 0.05).

CONCLUSIONS

Livers of aged mice exhibited different apoptotic processes compared to those of young mice early after burn injury. Collectively, burn-induced liver apoptosis in aged mice compromises hepatic serum protein production.

IDENTIFICATION OF SUBPHENOTYPES OF SEPSIS-ASSOCIATED LIVER DYSFUNCTION USING CLUSTER ANALYSIS

ABSTRACT

Objectives: We attempted to identify and validate the subphenotypes of sepsis-associated liver dysfunction (SALD) using routine clinical information. Design: This article is a retrospective observational cohort study. Setting: We used the Medical Information Mart for Intensive Care IV database and the eICU Collaborative Research Database. Patients: We included adult patients (age ≥18 years) who developed SALD within the first 48 hours of intensive care unit (ICU) admission. We excluded patients who died or were discharged from the ICU within the first 48 hours of admission. Patients with abnormal liver function before ICU admission were also excluded. Measurements and Main Results: Patients in the MIMIC-IV 1.0 database served as a derivation cohort. Patients in the eICU database were used as validation cohort. We identified four subphenotypes of SALD (subphenotype α, β, γ, δ) using K-means cluster analysis in 5234 patients in derivation cohort. The baseline characteristics and clinical outcomes were compared between the phenotypes using one-way analysis of variance/Kruskal-Wallis test and the χ 2 test. Moreover, we used line charts to illustrate the trend of liver function parameters over 14 days after ICU admission. Subphenotype α (n = 1,055) was the most severe cluster, characterized by shock with multiple organ dysfunction (MODS) group. Subphenotype β (n = 1,179) had the highest median bilirubin level and the highest proportion of patients with underlying liver disease and coexisting coagulopathy (increased bilirubin group). Subphenotype γ (n = 1,661) was the cluster with the highest mean age and had the highest proportion of patients with chronic kidney disease (aged group). Subphenotype δ (n = 1,683) had the lowest 28-day and in-hospital mortality (mild group). The characteristics of clusters in the validation cohort were similar to those in the derivation cohort. In addition, we were surprised to find that GGT levels in subphenotype δ were significantly higher than in other subphenotypes, showing a different pattern from bilirubin. Conclusions: We identified four subphenotypes of SALD that presented with different clinical features and outcomes. These results can provide a valuable reference for understanding the clinical characteristics and associated outcomes to improve the management of patients with SALD in the ICU.

Critical care hepatology: definitions, incidence, prognosis and role of liver failure in critically ill patients

Organ dysfunction or overt failure is a commonplace event in the critically ill affecting up to 70% of patients during their stay in the ICU. The outcome depends on the resolution of impaired organ function, while a domino-like deterioration of organs other than the primarily affected ones paves the way for increased mortality. “Acute Liver Failure” was defined in the 1970s as a rare and potentially reversible severe liver injury in the absence of prior liver disease with hepatic encephalopathy occurring within 8 weeks. Dysfunction of the liver in general reflects a critical event in “Multiple Organ Dysfunction Syndrome” due to immunologic, regulatory and metabolic functions of liver parenchymal and non-parenchymal cells. Dysregulation of the inflammatory response, persistent microcirculatory (hypoxic) impairment or drug-induced liver injury are leading problems that result in “secondary liver failure,” i.e., acquired liver injury without underlying liver disease or deterioration of preexisting (chronic) liver disease (“Acute-on-Chronic Liver Failure”). Conventional laboratory markers, such as transaminases or bilirubin, are limited to provide insight into the complex facets of metabolic and immunologic liver dysfunction. Furthermore, inhomogeneous definitions of these entities lead to widely ranging estimates of incidence. In the present work, we review the different definitions to improve the understanding of liver dysfunction as a perpetrator (and therapeutic target) of multiple organ dysfunction syndrome in critical care.

Graphic Abstract

Relationship between liver dysfunction, lipoprotein concentration and mortality during sepsis

Background

High-density lipoproteins (HDLs) are synthesized by the liver and display endothelioprotective properties, including anti-inflammatory, antiapoptotic, antithrombotic and antioxidant effects. In both septic and chronic liver failure patients, a low HDL cholesterol (HDL-C) concentration is associated with overmortality. Whereas sepsis-associated liver dysfunction is poorly defined, the aim of this study was to characterize the relationship between liver dysfunction, lipoprotein concentrations and mortality in septic patients in the intensive care unit (ICU).

Methods

A prospective observational study was conducted in a university hospital ICU. All consecutive patients admitted for septic shock or sepsis were included. Total cholesterol, HDL-C, low-density lipoprotein-cholesterol (LDL-C), and triglyceride levels were assessed at admission. Sepsis-associated liver dysfunction was defined as a serum bilirubin≥ 2N or aspartate aminotransferase/alanine aminotransferase concentrations ≥ 2N. Short-term and one-year prognostic outcomes were prospectively assessed.

Results

A total of 219 septic patients were included, and 15% of them presented with sepsis-associated liver dysfunction at admission. Low concentrations of lipoproteins were associated with mortality at Day 28 in the overall population. Sepsis-associated liver dysfunction at admission was associated with overmortality. In this subgroup, patients had a lower HDL-C concentration than patients without hepatic dysfunction (HDL-C = 0.31 [0.25, 0.55] mmol/L vs. 0.48 [0.29, 0.73] mmol/L, p = 0.0079) but there was no relationship with the outcome. Interestingly, no correlation was observed between lipoprotein concentrations and liver dysfunction markers.

Conclusion

Sepsis-associated liver dysfunction at ICU admission is strongly associated with overmortality and is associated with a lower HDL-C concentration. However, in this subgroup of patients, HDL-C concentration had no relationship with mortality. Further exploratory studies are needed to better understand the interaction between lipoproteins and liver dysfunction during sepsis.

Role of bile acids and their receptors in gastrointestinal and hepatic pathophysiology

Bile acids (BAs) can regulate their own metabolism and transport as well as other key aspects of metabolic homeostasis via dedicated (nuclear and G protein-coupled) receptors. Disrupted BA transport and homeostasis results in the development of cholestatic disorders and contributes to a wide range of liver diseases, including nonalcoholic fatty liver disease and hepatocellular and cholangiocellular carcinoma. Furthermore, impaired BA homeostasis can also affect the intestine, contributing to the pathogenesis of irritable bowel syndrome, inflammatory bowel disease, and colorectal and oesophageal cancer. Here, we provide a summary of the role of BAs and their disrupted homeostasis in the development of gastrointestinal and hepatic disorders and present novel insights on how targeting BA pathways might contribute to novel treatment strategies for these disorders.

Long-term ketamine infusion-induced cholestatic liver injury in COVID-19-associated acute respiratory distress syndrome

Background

A higher-than-usual resistance to standard sedation regimens in COVID-19 patients suffering from acute respiratory distress syndrome (ARDS) has led to the frequent use of the second-line anaesthetic agent ketamine. Simultaneously, an increased incidence of cholangiopathies in mechanically ventilated patients receiving prolonged infusion of high-dose ketamine has been noted. Therefore, the objective of this study was to investigate a potential dose–response relationship between ketamine and bilirubin levels.

Methods

Post hoc analysis of a prospective observational cohort of patients suffering from COVID-19-associated ARDS between March 2020 and August 2021. A time-varying, multivariable adjusted, cumulative weighted exposure mixed-effects model was employed to analyse the exposure–effect relationship between ketamine infusion and total bilirubin levels.

Results

Two-hundred forty-three critically ill patients were included into the analysis. Ketamine was infused to 170 (70%) patients at a rate of 1.4 [0.9–2.0] mg/kg/h for 9 [4–18] days. The mixed-effects model revealed a positively correlated infusion duration–effect as well as dose–effect relationship between ketamine infusion and rising bilirubin levels (p < 0.0001). In comparison, long-term infusion of propofol and sufentanil, even at high doses, was not associated with increasing bilirubin levels (p = 0.421, p = 0.258). Patients having received ketamine infusion had a multivariable adjusted competing risk hazard of developing a cholestatic liver injury during their ICU stay of 3.2 [95% confidence interval, 1.3–7.8] (p = 0.01).

Conclusions

A causally plausible, dose–effect relationship between long-term infusion of ketamine and rising total bilirubin levels, as well as an augmented, ketamine-associated, hazard of cholestatic liver injury in critically ill COVID-19 patients could be shown. High-dose ketamine should be refrained from whenever possible for the long-term analgosedation of mechanically ventilated COVID-19 patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04019-8.

Technical Note: Novel Use of CytoSorb™ Haemadsorption to Provide Wound Healing Support in Case of Severe Burn Trauma via Reduction of Hyperbilirubinaemia

Hyperbilirubinaemia has been shown to compromise wound healing in severely burned patients. The therapy options for patients with impairment of wound healing and subsequent severe liver dysfunction are limited. A novel extracorporeal treatment, CytoSorb^® (CytoSorbents Corp, USA), is a whole blood adsorber composed of highly biocompatible and porous polystyrene divinylbenzene copolymer beads covered in a polyvinylpyrrolidone coating. It is capable of extracting mainly hydrophobic middle-sized (up to 55 kDa) molecules from blood via size exclusion, including cytokines and bilirubin. We performed therapy with CytoSorb^® on a severely burned (48% Total Body Surface Area-TBSA) patient with secondary sclerosing cholangitis (SCC) to promote the wound healing process by reducing bilirubin concentrations and to bridge the time to spontaneous liver regeneration or eventually to liver transplantation after two skin transplantations had failed to provide wound closure. In the first 6 days the cartridge was changed on a daily basis and later after every 2–4 days. The therapy with six adsorbers decreased a total bilirubin concentration from 14.02 to 4.29 mg/dl. By maintaining a stable bilirubin concentration under 5 mg/dl, debridement of abdomen and upper extremities with autologous skin grafting and, 4 weeks later, autologous skin grafting of the back from scrotum and lower extremities were performed successfully. After wound healing had been achieved, the CytoSorb therapy was discontinued after 57 days and 27 adsorber changes. CytoSorb therapy can be a promising support of wound and skin graft healing in patients with severe burns and liver dysfunction due to a significant reduction of total bilirubin concentration.

Hepatic functional pathophysiology and morphological damage following severe burns: a systematic review and meta-analysis

INTRODUCTION

Severe burns are devastating injuries affecting multiple organ systems. Little is known about the influence on the hepatic system and its physiology. This systematic review aimed to assess the current state of research on morphologic liver damage following severe burns.

METHODS

A search was conducted in Pubmed, Web of Science and Cochrane databases using PRISMA guidelines. Outcomes included serum levels of transaminases, fatty infiltration and necrosis. Weighted individual study estimates were used to calculate pooled transaminase levels and necrosis/fatty infiltration rates using a random-effects approach. Risk ratios (RRs) or Odds ratios (ORs) and 95% confidence intervals (CIs) were used to describe pooled estimates for risk factors.

RESULTS

The literature search retrieved 2548 hits, of which 59 studies were included into qualitative synthesis, and finally ten studies were included into meta-analysis. Studies were divided into those reporting autopsies and those reporting changes of serum transaminase levels. The majority of liver autopsies showed fatty infiltration 82% (95% CI39%-97%) or necrosis of the liver 18% (95% CI13%-24%).

DISCUSSION

Heterogeneity in studies on hepatic functional damage following severe burns was high. Only few were well-designed and published in recent years. Many studies could not be included because of insufficient numerical data. There is a high number of patients deceasing from burns that present with fatty infiltration or necrosis of hepatic tissue. Transaminases were elevated during the first days after burn. Further research on how severe burns affect the hepatic function and outcome, especially long-term, is necessary.

Secondary sclerosing cholangitis as cause of persistent jaundice in patients with severe COVID-19

BACKGROUND & AIMS

Little is known about cholestasis, including its most severe variant secondary sclerosing cholangitis (SSC), in critically ill patients with coronavirus disease 19 (COVID-19). In this study, we analysed the occurrence of cholestatic liver injury and SSC, including clinical, serological, radiological and histopathological findings.

METHODS

We conducted a retrospective single-centre analysis of all consecutive patients admitted to the intensive care unit (ICU) as a result of severe COVID-19 at the University Hospital Zurich to describe cholestatic injury in these patients. The findings were compared to a retrospective cohort of patients with severe influenza A.

RESULTS

A total of 34 patients with severe COVID-19 admitted to the ICU were included. Of these, 14 patients (41%) had no cholestasis (group 0), 11 patients (32%, group 1) developed mild and 9 patients (27%, group 2) severe cholestasis. Patients in group 2 had a more complicated disease course indicated by significantly longer ICU stay (median 51 days, IQR 25-86.5) than the other groups (group 0: median 9.5 days, IQR 3.8-18.3, P = .001; and group 1: median 16 days, IQR 8-30, P < .05 respectively). Four patients in group 2 developed SSC compared to none in the influenza A cohort. The available histopathological findings suggest an ischaemic damage to the perihilar bile ducts.

CONCLUSIONS

The development of SSC represents an important complication of critically ill COVID-19 patients and needs to be considered in the diagnostic work up in prolonged cholestasis. The occurrence of SSC is of interest in the ongoing pandemic since it is associated with considerable morbidity and mortality.

Diarrhea and elevation of plasma markers of cholestasis are common and often occur concomitantly in critically ill patients

PURPOSE

We aimed to describe epidemiology of diarrhea and cholestasis in critically ill patients and explore associations between these two conditions.

MATERIAL AND METHODS

We performed a retrospective study including all consecutive patients who stayed in the ICU for at least 3 days and in whom plasma measurements of liver enzymes/cholestasis parameters were performed. Diarrhea was defined as 3 or more loose or liquid stools per day and cholestasis as increase of alkaline phosphatase (ALP) and gamma glutamyl transpeptidase (GGT) 1.5 times above the upper limit of normality.

RESULTS

Diarrhea was observed in 26.1% and cholestasis in 27.9% of study patients, about one third of the cases in both diarrhea and cholestasis occurred beyond the first week of patient's ICU stay. Cholestasis occurred in 45.6% of patients with diarrhea vs 28.0% of patients without diarrhea (p < 0.001). In 94 patients (13.1%) both diarrhea and cholestasis occurred, cholestasis was more commonly (2/3 of cases) documented before manifestation of diarrhea.

CONCLUSIONS

Cholestasis is more common in patients with diarrhea and vice versa. Diarrhea and cholestasis both occur in approximately one quarter of ICU patients, with significant proportion manifesting beyond the first week in the ICU.

L’hépatite hypoxique : ce que le réanimateur doit savoir

L’hépatite hypoxique est secondaire à une inadéquation entre les besoins hépatiques en oxygène et les apports sanguins. Elle est caractérisée par une augmentation rapide et transitoire de l’activité des transaminases sériques, prédominant souvent sur l’aspartate aminotransférase, chez un patient avec une ou plusieurs comorbidité(s), en particulier cardiaque(s). Le diagnostic est clinicobiologique et ne nécessite pas, en général, d’examen d’imagerie ou d’anatomopathologie. La lésion histologique sous-jacente est une nécrose de la zone centrale du lobule hépatique. L’hépatite hypoxique est souvent associée à une insuffisance rénale aiguë. Les facteurs de risque sont les cardiopathies favorisant la congestion hépatique, les hypoxémies, les altérations de lamicrocirculation hépatique, telles qu’on les observe au cours de la cirrhose. La prise en charge repose sur la correction de l’événement aigu et la restauration d’une perfusion et d’une oxygénation hépatique appropriées. Le pronostic est sombre avec une mortalité proche de 50 % et dépend essentiellement du délai de prise en charge de l’événement causal. Il est classique d’observer un syndrome de cholestase après une hépatite hypoxique résolutive. La lésion sous-jacente, encore mal comprise, est probablement une ischémie des petites voies biliaires intrahépatiques qui peut conduire, parfois, à des cholangites sclérosantes secondaires. L’objectif de cet article est de fournir au réanimateur l’ensemble des outils lui permettant d’identifier les situations à risque d’hépatite hypoxique et d’en faire le diagnostic le plus précocement possible afin de mettre en œuvre les mesures nécessaires.