Review article: controversies surrounding the use of carvedilol and other beta blockers in the management of portal hypertension and cirrhosis

BACKGROUND

Advanced chronic liver disease is an increasing cause of premature morbidity and mortality in the UK. Portal hypertension is the primary driver of decompensation, including the development of ascites, hepatic encephalopathy and variceal haemorrhage. Non-selective beta blockers (NSBB) reduce portal pressure and are well established in the prevention of variceal haemorrhage. Carvedilol, a newer NSBB, is more effective at reducing portal pressure due to additional α-adrenergic blockade and has additional anti-oxidant, anti-inflammatory and anti-fibrotic effects.

AIM

To summarise the available evidence on the use of beta blockers, specifically carvedilol, in cirrhosis, focussing on when and why to start METHODS: We performed a comprehensive literature search of PubMed for relevant publications.

RESULTS

International guidelines advise the use of NSBB in primary prophylaxis against variceal haemorrhage in those with high-risk varices, with substantial evidence of efficacy comparable with endoscopic band ligation (EBL). NSBB are also well established in secondary prophylaxis, in combination with EBL. More controversial is their use in patients without large varices, but with clinically significant portal hypertension. However, there is gathering evidence that NSBB, particularly carvedilol, reduce the risk of decompensation and improve survival. While caution is advised in patients with advanced cirrhosis and refractory ascites, recent evidence suggests that NSBB can continue to be used safely, and that premature discontinuation may be detrimental.

CONCLUSIONS

With increasing evidence of benefit independent of variceal bleeding, namely retardation of decompensation and improvement in survival, it is time to consider whether carvedilol should be offered to all patients with advanced chronic liver disease.

Reduced upper limb lean mass on dual energy X-ray absorptiometry predicts adverse outcomes in male liver transplant recipients

BACKGROUND

Pre-transplant muscle wasting measured by computed tomography has been associated with adverse clinical outcomes after liver transplantation including increased rates of sepsis and hospitalisation days. Upper limb lean mass (LM) measured by dual-energy X-ray absorptiometry (DEXA) was recently identified as a novel predictor of sarcopenia-associated mortality in men waitlisted for transplantation.

AIM

To investigate the use of DEXA LM in predicting gender-stratified early post-transplant outcomes.

METHODS

Liver transplant recipients who underwent pre-transplant DEXA body composition imaging between 2002 and 2017 were included. Endpoints included post-transplant mortality and graft failure, bacterial infections, acute cellular rejection (ACR) and intensive care and total hospital length of stay.

RESULTS

Four hundred and sixty-nine patients met inclusion criteria of which 338 were male (72%). Median age was 55.0 years (interquartile range 47.4, 59.7) and model for end-stage liver disease (MELD) score 16. Median time from assessment to transplantation was 7 mo (3.5, 12). Upper limb LM was inversely associated with bacterial infections at 180 d post-transplant (hazard ratio = 0.42; 95% confidence interval: 0.20-0.89; P = 0.024) in males only. There was a negative correlation between upper limb LM and intensive care (τ_b = -0.090, P = 0.015) and total hospital length of stay (τ_b = -0.10, P = 0.0078) in men. In women, neither MELD nor body composition parameters were associated with post-transplant adverse outcomes or increased length of stay. Body composition parameters, MELD and age were not associated with 90-d mortality or graft failure in either gender. There were no significant predictors of early ACR.

CONCLUSION

Sarcopenia is an independent and potentially modifiable predictor of increased post-transplant bacterial infections and hospital length of stay in men with cirrhosis. DEXA upper limb LM provides a novel measure of muscle wasting that has prognostic value in this cohort. The lack of association in women requires further investigation.

Body mass index is inversely associated with capillary ketones at the time of colonoscopy: Implications for SGLT2i use

OBJECTIVE

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been associated with diabetic ketoacidosis at the time of colonoscopy. This study aimed to identify factors associated with ketone concentrations in SGLT2i-treated type 2 diabetes compared with non-SGLT2i-treated diabetes, and those with impaired fasting glycaemia (IFG) and normoglycaemia.

DESIGN

Cross-sectional, multicentre, observational study June-December 2020 in four Australian tertiary hospitals.

PARTICIPANTS

Capillary glucose and ketones were measured in people undergoing colonoscopy: 37 SGLT2i-treated and 105 non-SGLT2i-treated type 2 diabetes, 65 IFG and 151 normoglycaemia.

MEASUREMENTS

Body mass index (BMI), age, glucose, fasting duration and where relevant, HbA1c and time since last SGLT2i dose.

RESULTS

In SGLT2i-treated diabetes, BMI (ρ = -0.43 [95% confidence interval: -0.67, -0.11]) and duration since last SGLT2i dose (ρ = -0.33 [-0.60, 0.00]) correlated negatively with increasing ketones, but there was no correlation with fasting duration. In non-SGLT2i-treated diabetes, BMI correlated negatively (ρ = -0.24 [-0.42, -0.05]) and fasting duration positively (ρ = 0.26 [0.07, 0.43]) with ketones. In IFG participants, only fasting duration correlated with ketones (ρ = 0.28 [0.03, 0.49]). In normoglycaemic participants, there were negative correlations with BMI (ρ = -0.20 [-0.35, -0.04]) and fasting glucose (ρ = -0.31 [-0.45, -0.15]) and positive correlations with fasting duration (ρ = 0.20 [0.04, 0.35]) and age (ρ = 0.19 [0.03, 0.34]). Multiple regression analysis of the entire cohort showed BMI, age and fasting glucose remained independently associated with ketones, but in SGLT2i-treated participants only BMI remained independently associated.

CONCLUSIONS

In SGLT2i-treated diabetes, lower BMI was a novel risk factor for higher ketones precolonoscopy. Pending larger confirmatory studies, extra vigilance for ketoacidosis is warranted in these people.

Epidemiology and outcomes of acute liver failure in Australia

BACKGROUND

Acute liver failure (ALF) is a life-threatening syndrome with varying aetiologies requiring complex care and multidisciplinary management. Its changing incidence, aetiology and outcomes over the last 16 years in the Australian context remain uncertain.

AIM

To describe the changing incidence, aetiology and outcomes of ALF in South Eastern Australia.

METHODS

The database of the Victorian Liver Transplant Unit was interrogated to identify all cases of ALF in adults (> 16 years) in adults hospitalised between January 2002 and December 2017. Overall, 169 patients meeting criteria for ALF were identified. Demographics, aetiology of ALF, rates of transplantation and outcomes were collected for all patients. Transplant free survival and overall survival (OS) were assessed based on survival to discharge from hospital. Results were compared to data from a historical cohort from the same unit from 1988-2001.

RESULTS

Paracetamol was the most common aetiology of acute liver failure, accounting for 50% of cases, with an increased incidence compared with the historical cohort (P = 0.046). Viral hepatitis and non-paracetamol drug or toxin induced liver injury accounted for 15% and 10% of cases respectively. Transplant free survival (TFS) improved significantly compared to the historical cohort (52% vs 38%, P = 0.032). TFS was highest in paracetamol toxicity with spontaneous recovery in 72% of cases compared to 31% of non-paracetamol ALF (P < 0.001). Fifty-nine patients were waitlisted for emergency liver transplantation. Nine of these died while waiting for an organ to become available. Forty-two patients (25%) underwent emergency liver transplantation with a 1, 3 and 5 year survival of 81%, 78% and 72% respectively.

CONCLUSION

Paracetamol toxicity is the most common aetiology of ALF in South-Eastern Australia with a rising incidence over 30 years. TFS has improved, however it remains low in non-paracetamol ALF.

Factors associated with vancomycin nephrotoxicity in the critically ill

Vancomycin is a glycopeptide antibiotic commonly used in the management of methicillin-resistant Staphylococcus aureus infection. The recent increase in prevalence of methicillin-resistant Staphylococcus aureus with reduced susceptibility to vancomycin has prompted experts to advocate for higher target trough serum concentrations. This study aimed to evaluate the potential consequences of more aggressive vancomycin therapy, by examining the association between higher serum concentrations and acute kidney injury (AKI) in a population of critically ill patients. We collected data for all patients who received vancomycin over a five-year period and evaluated the prevalence of new-onset AKI using the Risk, Injury, Failure, Loss and End-stage (RIFLE) kidney disease criteria. One-hundred and fifty-nine patients provided complete data, with 8.8% manifesting new onset AKI while receiving vancomycin. The median age was 57 (44 to 68) years, while the median trough serum concentration was 16 (10 to 19) mg/l. Multivariate logistic regression analysis identified mean trough concentration (OR=1.174, P=0.024), APACHE II score (OR=1.141, P=0.012) and simultaneous aminoglycoside prescription (OR=18.896, P=0.002) as significant predictors of AKI. These data suggest higher trough vancomycin serum concentrations are associated with greater odds of AKI in the critically ill.