Mark McPhail

Lessons from look-back in acute liver failure? A single centre experience of 3300 patients.

BACKGROUND & AIMS Acute liver failure (ALF) is a rapidly progressive critical illness with high mortality. Complex intensive care unit (ICU) protocols and emergency liver transplantation (ELT) are now often available, but rarity and severity of illness have limited its study and evidence-base for care. We reviewed patients treated over a 35-year period at a specialist high-volume ICU, quantifying changes in disease aetiology, severity and evolution of ICU support and ELT use and outcome. METHODS Review of adult patients admitted during the period 1973-2008, with acute liver dysfunction and coagulopathy with overt hepatic encephalopathy (ALF) and those without (acute liver injury; ALI). RESULTS 3305 patients fulfilled inclusion criteria, 2095 with ALF. Overall hospital survival increased from 30% in 1973-78 to 76% in 2004-08; in ALF from 17% to 62% (both p<0.0001). In ALF patients treated without ELT, survival rose from 17% to 48% (p<0.0001); in those undergoing ELT (n=387) from 56% in 1984-88 to 86% in 2004-08 (p<0.01). Coincident with drug sales-restriction, paracetamol-related admissions fell significantly. Viral admissions fell from 56% to 17% of non-paracetamol cases (p<0.0001). Admission markers of liver injury severity fell significantly and the proportion of patients with intracranial hypertension (ICH) fell from 76% in 1984-88 to 20% in 2004-08 (p<0.0001). In those with ICH, mortality fell from 95% to 55% (p<0.0001). CONCLUSIONS The nature and outcome of ALF have transformed over 35 years, with major improvements in survival and a fall in prevalence of cerebral oedema and ICH, likely consequent upon earlier illness recognition, improved ICU care, and use of ELT.

Source and characterization of hepatic macrophages in acetaminophen‐induced acute liver failure in humans

Acetaminophen‐induced acute liver failure (AALF) is associated with innate immunity activation, which contributes to the severity of hepatic injury and clinical outcome. A marked increase in hepatic macrophages (h‐mϕ) is observed in experimental models of AALF, but controversy exists regarding their role, implicating h‐mϕ in both aggravation and resolution of liver injury. The role of h‐mϕ in human AALF is virtually unexplored. We sought to investigate the role of chemokine (C‐C motif) ligand 2 (CCL2) in the recruitment of circulating monocytes to the inflamed liver and to determine how the h‐mϕ infiltrate and liver microenvironment may contribute to tissue repair versus inflammation in AALF. We evaluated circulating monocytes, their chemokine (C‐C motif) receptor 2 (CCR2) expression, and serum CCL2 levels in patients with AALF. Cell subsets and numbers of circulation‐derived (MAC387+) or resident proliferating (CD68/Ki67+) h‐mϕ in hepatic immune infiltrates were determined by immunohistochemistry. Inflammatory cytokine levels were determined in whole and laser microdissected liver tissue by proteome array. In AALF, circulating monocytes were depleted, with the lowest levels observed in patients with adverse outcomes. CCL2 levels were high in AALF serum and hepatic tissue, and circulating monocyte subsets expressed CCR2, suggesting CCL2‐dependent hepatic monocyte recruitment. Significant numbers of both MAC387+ and CD68+ h‐mϕ were found in AALF compared with control liver tissue with a high proportion expressing the proliferation marker Ki67. Levels of CCL2, CCL3, interleukin (IL)‐6, IL‐10, and transforming growth factor‐β1 were significantly elevated in AALF liver tissue relative to chronic liver disease controls. Conclusion: In AALF, the h‐mϕ population is expanded in areas of necrosis, both through proliferation of resident cells and CCL2‐dependent recruitment of circulating monocytes. The presence of h‐mϕ within an anti‐inflammatory/regenerative microenvironment indicates that they are implicated in resolution of inflammation/tissue repair processes during AALF. (HEPATOLOGY 2012)

Endoscopic ultrasound guided fine needle aspiration for the diagnosis of pancreatic cystic neoplasms: a meta-analysis.

BACKGROUND AND OBJECTIVES Mucinous cystic neoplasms and intraductal papillary mucinous tumours have greater malignant potential than serous cystic neoplasms. EUS alone is inadequate for characterising these lesions but the addition of FNA may significantly improve diagnostic accuracy. The performance of EUS-FNA is highly variable in published studies. AIM To determine the diagnostic accuracy of EUS-FNA to differentiate mucinous versus non-mucinous cystic lesions with cyst fluid analysis for cytology and carcinoembryonic antigen (CEA) by performing a meta-analysis of published studies. METHODS Relevant studies were identified via structured database search and included if they used a reference standard of definitive surgical histology or clinical follow-up of at least 6 months. Data from selected studies were pooled to give summary sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio and Receiver Operating Characteristic (ROC) curve. Pre-defined subgroup analysis was performed. RESULTS Eighteen studies (published 2002-2011) were included, with a total of 1438 patients. For cytology, pooled sensitivity was 54(95%CI 49-59)% and specificity 93(90-95)%. The diagnostic odds ratio (DOR) was 13.3 (4.37-49.43), with I(2) of 77.1%. For CEA sensitivity was 63(59-67)% and specificity 88(83-91)%. The DOR was 10.76(6.29-18.41) with an I(2) of 25.4%. The diagnostic accuracy of EUS-FNA was enhanced in prospective studies and studies of <36 months duration. No impact of publication bias on our results was demonstrated. CONCLUSIONS Fine-needle aspiration has moderate sensitivity but high specificity for mucinous lesions. EUS-FNA, when used in conjunction with cross sectional imaging, is a useful diagnostic tool for the correct identification of mucinous cysts.

CD14, CD16 and HLA-DR reliably identifies human monocytes and their subsets in the context of pathologically reduced HLA-DR expression by CD14(hi) /CD16(neg) monocytes: Expansion of CD14(hi) /CD16(pos) and contraction of CD14(lo) /CD16(pos) monocytes in acute liver failure

Changes in monocytes and their subsets (CD14hi/CD16neg, CD14hi/CD16pos and CD14lo/CD16pos) have been described in several diseases. The combination of CD14, CD16 and HLA‐DR has been suggested to discriminate monocytes from the CD16pos/HLA‐DRneg NK‐cells and neutrophils but no data exist whether this strategy can be used in situations when monocyte HLA‐DR expression is pathologically reduced. Monocytes and their subsets were concurrently identified through negative (exclusion of CD66bpos neutrophils, CD56pos NKcells, CD19pos B‐cells, and CD3pos T‐cells) and positive gating (inclusion of monocytes by expression of CD14, CD16, and HLA‐DR) strategies on 30 occasions [9 healthy controls (HC) and 21 patients with conditions associated with low monocyte HLA‐DR expression]. Bland‐Altman and Passing and Bablok regression statistics did not demonstrate any significant measurement bias between the two strategies of monocyte identification. Monocyte subset phenotype was then compared in 18 HC and 41 patients with acute liver failure (ALF). Compared with HC, in ALF, the percentage of CD14hi/CD16pos monocytes was higher (7% vs 4%) whilst the percentage of CD14lo/CD16pos was lower (1.9% vs. 7%) (P ≤ 0.001); HLA‐DR and CD86 MFIs on all monocyte subsets were lower, whilst CCR5, CD64, and CD11b MFIs were higher (P < 0.05). The relative expression by monocyte subsets of HLA‐DR, CCR2, CCR5, CX3CR1, and CD11a was similar in ALF patients and HCs. Repeat analysis of an identical antibody‐fluorochrome “backbone” targeting HLA‐DR, CD14, and CD16 was assessed in 189 samples across 5 different experiments. There was excellent agreement in the results obtained using the positive gating strategy (interclass correlation coefficients > 0.8). Monocytes and their subsets can be reliably identified using an antibody‐fluorochrome “backbone” of HLA‐DR, CD14, and CD16. CD16pos monocytes continue to constitutively express HLA‐DR even in conditions where HLA‐DR is pathologically reduced on CD14hi/CD16neg monocytes. Understanding the changes in monocyte pheontype in ALF and similar clinico‐pathological diseases may allow the development of novel biomarkers or therapeutic strategies.

Bacteremia, acute physiology and chronic health evaluation II and modified end stage liver disease are independent predictors of mortality in critically ill nontransplanted patients with acute on chronic liver failure

Objectives:To determine what physiological and biochemical factors predict development of bacteremia in nontransplanted patients with acute on chronic liver failure and, on diagnosis of bacteremia, what is the natural history of bacteremic patients versus control subjects (acute on chronic liver failure). Interventions:None. Design:Retrospective analysis of data collected prospectively and entered into a dedicated physiology database. Setting:Specialist liver intensive therapy unit. Patients:Critically ill non-transplanted patients with acute on chronic liver failure admitted between January 2003 and July 2005. Measurements and Main Results:One hundred eighty-four patients were defined with acute on chronic liver failure; 67 (36%) had bacteremia. One hundred seventeen (64%) patients did not (acute on chronic liver failure). Fifty-eight percent of isolates were Gram-negative organisms, 36% were Gram-positives, and 6% fungemia. Median time to first bacteremia was 8 days (range, 3–12 days). On admission (univariate), bacteremic patients had significantly higher Modified End Stage Liver Disease scores (27 vs. 24, p = .037), Acute Physiology and Chronic Health Evaluation II scores (23 vs. 21, p = .049), and greater degrees of encephalopathy (Glasgow Coma Scale score 10 vs. 12, p = .001). During their liver intensive therapy unit course, bacteremic patients had significantly greater requirements for renal replacement therapy (64% vs. 49%, p = .043), mechanical ventilation (88% vs. 68%, p = .002), and a longer median liver intensive therapy unit stay (16 vs. 5 days, p < .001). Survival to hospital discharge was worse in the bacteremic group (25% vs. 56%, p < .001). Multivariate analysis (logistic regression) was performed separately modeling with Acute Physiology and Chronic Health Evaluation II and Modified End Stage Liver Disease. In the first model, Acute Physiology and Chronic Health Evaluation II (odds ratio 1.24) and bacteremia (2.24) were independent predictors of mortality. In the later model, Modified End Stage Liver Disease (odds ratio, 1.06), requirement for renal replacement therapy (3.08), Glasgow Coma Scale (0.72), and bacteremia (2.30) were significant. Both models performed similarly (Modified End Stage Liver Disease area under the receiver operating characteristic curve, 0.864; Acute Physiology and Chronic Health Evaluation II, 0.862). Conclusions:In nontransplanted patients with acute on chronic liver failure, bacteremia was associated with increased severity of illness on admission, greater requirements for organ support, and independently adversely impacted on survival. Higher Acute Physiology and Chronic Health Evaluation II and Modified End Stage Liver Disease scores were also independently predictive of mortality.

Neutrophil gelatinase—Associated lipocalin predicts acute kidney injury in patients undergoing liver transplantation

Postoperative acute kidney injury (AKI) increases morbidity and mortality after liver transplantation (LT). Novel methods of assessing AKI including cystatin C (CyC) and neutrophil gelatinase–associated lipocalin (NGAL) have been identified as potential markers of AKI. We compare the ability of standard renal markers (serum creatinine [sCr], estimated glomerular filtration rate [eGFR] and intensive therapy unit organ failure scores with CyC and NGAL to predict AKI within the first 48 hours after LT. 95 patients (median age 50 [interquartile range = 41‐59], 60% male) underwent LT (25% with acute liver failure). AKI was defined according to the Acute Kidney Injury Network criteria. Severe AKI was classified as ≥stage 2. NGAL (urine [u] and plasma [p]) and CyC concentrations taken immediately after transplantation on admission to the Liver Intensive Care Unit were compared with standard markers of renal function. Predictive ability was assessed using the area under the curve generated by receiver operator characteristic analysis (AUROC) and logistic regression. Day 0 sCr, uNGAL, pNGAL, CyC, and eGFR predicted AKI as did SOFA (Sequential Organ Failure Assessment) and APACHE II (Acute Physiology and Chronic Health Evaluation II) scores. APACHE II and pNGAL were the most powerful predictors of severe AKI (APACHE II AUROC = 0.87 [0.77‐0.97], P < 0.001; pNGAL AUROC = 0.87 [0.77‐0.92], P < 0.001). Using multivariate logistic regression, APACHE II (odds ratio 1.64/point [95% confidence interval = 1.22‐2.21, P = 0.001] and pNGAL [odds ratio = 1.01/ng/mL [95% confidence interval = 1.00‐1.02], P = 0.002) retained independent significance. A “renal risk score” using APACHE II > 13 and pNGAL > 258 ng/mL was calculated with a score of ≥1 having a 100% sensitivity and 76% specificity for severe AKI. In conclusion, a combination of NGAL and APACHE II predicts AKI with high sensitivity and specificity after LT. Liver Transpl 16:1257‐1266, 2010.

A Simultaneous X-Ray/MRI and Noncontact Mapping Study of the Acute Hemodynamic Effect of Left Ventricular Endocardial and Epicardial Cardiac Resynchronization Therapy in Humans

Background—Cardiac resynchronization therapy (CRT) using endocardial left ventricular (LV) pacing may be superior to conventional CRT. We studied the acute hemodynamic response to conventional CRT and LV pacing from different endocardial sites using a combined cardiac MRI and LV noncontact mapping (NCM) protocol to gain insights into the underlying mechanisms. Methods and Results—Fifteen patients (age, 63±10 years; 12 men) awaiting CRT were studied in a combined x-ray and MRI laboratory. Delayed-enhancement cardiac magnetic resonance was performed to define areas of myocardial fibrosis. Patients underwent an electrophysiological study incorporating endocardial and epicardial LV pacing. Acute hemodynamic response was measured using a pressure wire within the LV cavity to derive LV dP/dt max. NCM was used to define areas of slow conduction. There was a significant improvement in all LV pacing modes versus baseline (P<0.001). LV endocardial CRT from the best endocardial site was superior to conventional CRT, with a 79.8±49.0% versus 59.6±49.5% increase in LV dP/dt max of from baseline (P<0.05). The hemodynamic benefits of pacing were greater when LV stimulation was performed outside of areas of slow conduction defined by NCM (P<0.001). Delayed-enhancement cardiac magnetic resonance was able to delineate zones of slow conduction seen with NCM in ischemic patients but was unreliable in nonischemic patients. Conclusions—Endocardial LV pacing appears superior to conventional CRT, although the optimal site varies between subjects and is influenced by pacing within areas of slow conduction. Delayed-enhancement cardiac magnetic resonance was a poor predictor of zones of slow conduction in nonischemic patients.

Predictors of bacteraemia and mortality in patients with acute liver failure

PurposeTo determine what physiological and biochemical factors predict development of bacteraemia and mortality in patients with acute liver failure (ALF).MethodsRetrospective analysis of 206 ALF patients admitted to a specialist liver intensive therapy unit (LITU) from January 2003 to July 2005 (data collected prospectively).ResultsA total of 206 patients were defined with ALF: 72 (35%) suffered bacteraemia (BAClf) and 134 (65%) did not (NBAClf). Gram positive organisms were observed in 44% of isolates, gram negatives in 52% and fungaemia in 4%. Median time to first bacteraemia was 10 (7–16) days. On admission, BAClf patients had higher SIRS scores and degrees of hepatic encephalopathy (HE). During their LITU course, BAClf patients had significantly increased requirements for renal replacement therapy (RRT), mechanical ventilation, and longer median LITU stay. Multivariate analysis (logistical regression) demonstrated significant predictors of bacteraemia on admission were HE grade >2 (Odds Ratio 1.6) and SIRS score >1 (OR 2.7). In all patients, independent predictors of mortality (logistical) were age (OR 1.41), maximum HE grade pre-intubation (1.76), Lactate (1.14) and Acute Physiology and Chronic Health Evaluation II score (APACHEII) (1.09), but not bacteraemia. Transplantation was protective (OR 0.20).ConclusionIn this study, severity of hepatic encephalopathy and SIRS score >1 were predictive of bacteraemia. APACHEII was independently predictive of mortality in all ALF patients but not bacteraemia.

Bile Acid Profiling and Quantification in Biofluids Using Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry

Bile acids are important end products of cholesterol metabolism. While they have been identified as key factors in lipid emulsification and absorption due to their detergent properties, bile acids have also been shown to act as signaling molecules and intermediates between the host and the gut microbiota. To further the investigation of bile acid functions in humans, an advanced platform for high throughput analysis is essential. Herein, we describe the development and application of a 15 min UPLC procedure for the separation of bile acid species from human biofluid samples requiring minimal sample preparation. High resolution time-of-flight mass spectrometry was applied for profiling applications, elucidating rich bile acid profiles in both normal and disease state plasma. In parallel, a second mode of detection was developed utilizing tandem mass spectrometry for sensitive and quantitative targeted analysis of 145 bile acid (BA) species including primary, secondary, and tertiary bile acids. The latter system was validated by testing the linearity (lower limit of quantification, LLOQ, 0.25-10 nM and upper limit of quantification, ULOQ, 2.5-5 μM), precision (≈6.5%), and accuracy (81.2-118.9%) on inter- and intraday analysis achieving good recovery of bile acids (serum/plasma 88% and urine 93%). The ultra performance liquid chromatography-mass spectrometry (UPLC-MS)/MS targeted method was successfully applied to plasma, serum, and urine samples in order to compare the bile acid pool compositional difference between preprandial and postprandial states, demonstrating the utility of such analysis on human biofluids.

Pacemaker and Defibrillator Lead Extraction: Predictors of Mortality during Follow‐Up

Background: Extraction of cardiac implantable electric devices is an accepted procedure when systems become infected or malfunction. However, there is an associated morbidity and mortality. We report our 5‐year experience and identify predictors of mortality, and long‐term follow‐up.