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Timothy J Davern

Publications and source records attributed to Timothy J Davern.

13 recordsLinked to original sources

Measurement of serum acetaminophen-protein adducts in patients with acute liver failure.

BACKGROUND & AIMS: Acetaminophen toxicity is the most common cause of acute liver failure (ALF) in the United States and Great Britain, but may be underrecognized in certain settings. Acetaminophen-protein adducts are specific biomarkers of drug-related toxicity in animal models and can be measured in tissue or blood samples. Measurement of serum adducts might improve diagnostic accuracy in acute liver failure (ALF) patients. METHODS: We measured serum acetaminophen-protein adducts using high-pressure liquid chromatography with electrochemical detection in coded sera of 66 patients with ALF collected prospectively at 24 US tertiary referral centers. Samples were included from 20 patients with well-characterized acetaminophen-related acute liver failure, 10 patients with ALF owing to other well-defined causes, 36 patients with ALF of indeterminate etiology, and 15 additional patients without ALF but with known acetaminophen overdose and minimal or no biochemical liver injury. RESULTS: Acetaminophen-protein adducts were detected in serum in 100% of known acetaminophen ALF patients and in none of the ALF patients with other defined causes, yielding a sensitivity and specificity of 100%. In daily serial samples, serum adducts decreased in parallel with aminotransferase levels. Seven of 36 (19%) indeterminate cases demonstrated adducts in serum suggesting that acetaminophen toxicity caused or contributed to ALF in these patients. Low adduct levels were present in 2 of 15 patients with acetaminophen overdose without significant liver injury. CONCLUSIONS: Measurement of serum acetaminophen-protein adducts reliably identified acetaminophen toxicity, and may be a useful diagnostic test for cases lacking historical data or other clinical information.

Acetaminophen↗

Detection of acetaminophen protein adducts in children with acute liver failure of indeterminate cause.

OBJECTIVE: Acetaminophen cysteine protein adducts are a widely recognized correlate of acetaminophen-mediated hepatic injury in laboratory animals. The objective of this study was to use a new assay for the detection of acetaminophen cysteine protein adducts in children with acute liver failure to determine the role of acetaminophen toxicity in acute liver failure of unknown cause. METHODS: Serum samples from children with acute liver failure were measured for acetaminophen cysteine protein adducts using high-performance liquid chromatography with electrochemical detection. For comparison, samples from children with well-characterized acetaminophen toxicity and children with known other causes of acute liver failure also were measured for acetaminophen cysteine protein adducts. The analytical laboratory was blinded to patient diagnoses. RESULTS: Acetaminophen cysteine protein adduct was detected in 90% of samples from children with acute liver failure that was attributed to acetaminophen toxicity, 12.5% of samples from children with acute liver failure of indeterminate cause, and 9.6% of samples from children with acute liver failure that was attributed to other causes. Adduct-positive patients from the indeterminate cause subgroup had higher levels of serum aspartate aminotransferase and alanine aminotransferase and lower levels of bilirubin. Adduct-positive patients also had lower rates of transplantation and higher rates of spontaneous remission. CONCLUSIONS: A small but significant percentage of children with acute liver failure of indeterminate cause tested positive for acetaminophen cysteine protein adducts, strongly suggesting acetaminophen toxicity as the cause of acute liver failure. An assay for the detection of acetaminophen cysteine protein adducts can aid the diagnosis of acetaminophen-related liver injury in children.

Acetaminophen↗

Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study.

Severe acetaminophen hepatotoxicity frequently leads to acute liver failure (ALF). We determined the incidence, risk factors, and outcomes of acetaminophen-induced ALF at 22 tertiary care centers in the United States. Detailed prospective data were gathered on 662 consecutive patients over a 6-year period fulfilling standard criteria for ALF (coagulopathy and encephalopathy), from which 275 (42%) were determined to result from acetaminophen liver injury. The annual percentage of acetaminophen-related ALF rose during the study from 28% in 1998 to 51% in 2003. Median dose ingested was 24 g (equivalent to 48 extra-strength tablets). Unintentional overdoses accounted for 131 (48%) cases, intentional (suicide attempts) 122 (44%), and 22 (8%) were of unknown intent. In the unintentional group, 38% took two or more acetaminophen preparations simultaneously, and 63% used narcotic-containing compounds. Eighty-one percent of unintentional patients reported taking acetaminophen and/or other analgesics for acute or chronic pain syndromes. Overall, 178 subjects (65%) survived, 74 (27%) died without transplantation, and 23 subjects (8%) underwent liver transplantation; 71% were alive at 3 weeks. Transplant-free survival rate and rate of liver transplantation were similar between intentional and unintentional groups. In conclusion, acetaminophen hepatotoxicity far exceeds other causes of acute liver failure in the United States. Susceptible patients have concomitant depression, chronic pain, alcohol or narcotic use, and/or take several preparations simultaneously. Education of patients, physicians, and pharmacies to limit high-risk use settings is recommended.

APACHE↗

A prospective study on downstaging of hepatocellular carcinoma prior to liver transplantation.

In patients with hepatocellular carcinoma (HCC) exceeding conventional (T2) criteria for orthotopic liver transplantation (OLT), the feasibility and outcome following loco-regional therapy intended for tumor downstaging to meet T2 criteria for OLT are unknown. In this first prospective study on downstaging of HCC prior to OLT, the eligibility criteria for enrollment into a downstaging protocol included 1 lesion >5 cm and < or =8 cm, 2 or 3 lesions at least 1 >3 cm but < or =5 cm with total tumor diameter of < or =8 cm, or 4 or 5 nodules all < or =3 cm with total tumor diameter < or =8 cm. Patients were eligible for living-donor liver transplantation (LDLT) if tumors were downstaged to within proposed University of California, San Francisco (UCSF) criteria.13 A minimum follow-up period of 3 months after downstaging was required before cadaveric OLT or LDLT, with imaging studies meeting criteria for successful downstaging. Among the 30 patients enrolled, 21 (70%) met criteria for successful downstaging, including 16 (53%) who had subsequently received OLT (2 with LDLT), and 9 patients (30%) were classified as treatment failures. In the explant of 16 patients who underwent OLT, 7 had complete tumor necrosis, 7 met T2 criteria, but 2 exceeded T2 criteria. No HCC recurrence was observed after a median follow-up of 16 months after OLT. The Kaplan-Meier intention-to-treat survival was 89.3 and 81.8% at 1 and 2 yr, respectively. In conclusion, successful tumor downstaging can be achieved in the majority of carefully selected patients, but longer follow-up is needed to further access the risk of HCC recurrence after OLT.

Aged↗

Complications and use of intracranial pressure monitoring in patients with acute liver failure and severe encephalopathy.

Monitoring of intracranial pressure (ICP) in acute liver failure (ALF) is controversial as a result of the reported complication risk (approximately 20%) and limited therapeutic options for intracranial hypertension. Using prospectively collected information from 332 patients with ALF and severe encephalopathy, we evaluated a recent experience with ICP monitoring in the 24 centers constituting the U.S. ALF Study Group. Special attention was given to the rate of complications, changes in management, and outcome after liver transplantation (LT). ICP monitoring was used in 92 patients (28% of the cohort), but the frequency of monitoring differed between centers (P < 0.001). ICP monitoring was strongly associated with the indication of LT (P < 0.001). A survey performed in a subset of 58 patients with ICP monitoring revealed intracranial hemorrhage in 10.3% of the cohort, half of the complications being incidental radiological findings. However, intracranial bleeding could have contributed to the demise of 2 patients. In subjects listed for LT, ICP monitoring was associated with a higher proportion of subjects receiving vasopressors and ICP-related medications. The 30-day survival post-LT was similar in both monitored and nonmonitored groups (85% vs. 85%). In conclusion, the risk of intracranial hemorrhage following ICP monitoring may have decreased in the last decade, but major complications are still present. In the absence of ICP monitoring, however, patients listed for LT appear to be treated less aggressively for intracranial hypertension. In view of the high 30-day survival rate after LT, future studies of the impact of intracranial hypertension should also focus on long-term neurological recovery from ALF.

Adult↗

Leukotriene antagonists.

Hepatotoxicity is the most common cause of fulminant hepatic failure in the United States and the main indication for market withdrawal of drugs. This condition has been increasingly recognized as a problem of enormous medical, financial legal, and regulatory importance. It is in context of this heightened awareness of hepatotoxicity, particularly associated with new high profile drugs, that the authors reviews the published data regarding liver injury related to a novel group of asthma drugs.

Adult↗

A follow-up analysis of the pattern and predictors of dropout from the waiting list for liver transplantation in patients with hepatocellular carcinoma: implications for the current organ allocation policy.

Since our interim report of the intention-to-treat outcome of orthotopic liver transplantation (OLT) for hepatocellular carcinoma (HCC), we have performed a follow-up analysis of an expanded cohort of 70 patients to further assess whether the observed pattern and predictors of dropout are consistent with the rationale behind current HCC-adjusted Model for End Stage Liver Disease (MELD) organ allocation scheme. All except one patient had pretransplantation staging meeting our proposed expanded criteria-a single lesion < or =6.5 cm, or three or fewer lesions none >4.5 cm and total tumor diameter < or =8 cm. Thirty-eight patients received OLT. The cumulative probabilities of dropout at 6, 12, and 18 months were 7.2%, 37.8%, and 55.1%, respectively. The respective dropout probabilities would have been 11.0%, 57.4%, and 68.7% if the United Network for Organ Sharing (UNOS) criteria for exclusion (single lesion < or =5 cm or three or fewer lesions none >3 cm) were applied. Predictors of dropout with either criteria included three tumor nodules and a single lesion >3 cm at initial presentation, whereas preoperative chemoembolization or ablation therapies were associated with a lower risk for dropout only when applying the UNOS criteria for patient exclusion. In the subgroup with two or three lesions or a solitary tumor >3 cm, the cumulative probabilities of dropout were nine-fold higher than those with a single lesion < or =3 cm (P =.004). In conclusion, the low dropout rate in the first 6 months and the differing dropout risks based on tumor characteristics support further refinements in the HCC-adjusted MELD organ allocation scheme.

Adult↗

Viral hepatitis-related acute liver failure.

OBJECTIVES: Viral hepatitis has previously been the major cause of acute liver failure (ALF) in the United States. We aimed to determine the incidence of viral hepatitis-related ALF and to compare the outcome and clinical and biochemical variables in patients with hepatitis A and B. METHODS: A total of 354 patients with ALF from multiple centers were screened for possible acute viral etiology. RESULTS: Forty-three patients (12.1% of all ALF cases) had acute viral hepatitis: hepatitis A (n = 16), hepatitis B (n = 26), and herpes simplex virus infection (n = 1). There was no difference between groups with regard to age, gender, body mass index, admission or peak coma grade, symptom duration, admission mean arterial pressure, temperature, or biochemical liver tests, creatinine, arterial pH, or rate of infections. Platelet count was significantly higher in hepatitis A patients than in hepatitis B patients. The transplantation-free (spontaneous) survival rate was significantly higher for hepatitis A patients (69%) than for hepatitis B patients (19%, p = 0.007), whereas the liver transplantation rate was higher in hepatitis B patients (62%) than in hepatitis A patients (19%, p = 0.017). Spontaneous survivors had significantly higher mean arterial pressure, higher platelet count, and lower AST/ALT ratio than patients who did not survive spontaneously. CONCLUSIONS: Viral hepatitis now comprises only one-eighth of all ALF cases in the United States. The marked difference in spontaneous survival between hepatitis A and B cannot be explained by the severity of hepatic dysfunction on admission but may rather be an inherent feature of the infections or a bias toward transplanting patients with hepatitis B.

Adult↗

Results of a prospective study of acute liver failure at 17 tertiary care centers in the United States.

BACKGROUND: Because acute liver failure is rare, related data have been sparse. Studies have suggested that viral hepatitis is the most common underlying cause of this condition. OBJECTIVE: To describe the clinical features, presumed causes, and short-term outcomes of acute liver failure. DESIGN: Prospective cohort study. SETTING: 17 tertiary care centers participating in the U.S. Acute Liver Failure Study Group. PATIENTS: 308 consecutive patients with acute liver failure, admitted over a 41-month period. MEASUREMENTS: Detailed clinical and laboratory data collected during hospitalization, including outcome 3 weeks after study admission. RESULTS: 73% of patients were women; median age was 38 years. Acetaminophen overdose was the most common apparent cause of acute liver failure, accounting for 39% of cases. Idiosyncratic drug reactions were the presumptive cause in 13% of cases, viral hepatitis A and B combined were implicated in 12% of cases, and 17% of cases were of indeterminate cause. Overall patient survival at 3 weeks was 67%. Twenty-nine percent of patients had liver transplantation, and 43% survived without transplantation. Short-term transplant-free survival varied greatly, from 68% for patients with acetaminophen-related liver failure to 25% and 17% for those with other drug reactions and liver failure of indeterminate cause, respectively. Coma grade at admission appeared to be associated with outcome, but age and symptom duration did not. CONCLUSIONS: Acetaminophen overdose and idiosyncratic drug reactions have replaced viral hepatitis as the most frequent apparent causes of acute liver failure. Apparent cause and coma grade at admission were associated with outcome. Although transplantation may improve patient survival, it was unavailable or unnecessary for most patients.

Acetaminophen↗

Liver transplantation for hepatocellular carcinoma: analysis of survival according to the intention-to-treat principle and dropout from the waiting list.

A major obstacle for orthotopic liver transplantation (OLT) as treatment for hepatocellular carcinoma (HCC) is tumor growth resulting in dropout from the waiting list for OLT. There is a paucity of data on survival according to intention-to-treat analysis and the rate of dropout from the waiting list for OLT among patients with HCC. To further evaluate these issues, we analyzed the outcome of 46 consecutive patients with HCC listed for OLT between January 1998 and January 2001. Exclusion criteria for OLT were tumor size greater than 5 cm for one to three lesions or four lesions or greater of any size. Twenty-one patients underwent OLT. There were 11 dropouts because of tumor progression and six deaths, including three deaths after dropout. Kaplan-Meier 1- and 2-year intention-to-treat survival rates were 91.7% and 72.6%, respectively. Monthly dropout rates were 0% from 0 to 3 months, 1.5% from 3 to 6 months, 1.0% from 6 to 9 months, 4.9% from 9 to 12 months, and 5.6% from 12 to 15 months. One dropout occurred beyond 15 months among 4 patients remaining at risk. Cumulative probabilities for dropout at 6, 12, and 24 months were 7.3%, 25.3%, and 43.6%, respectively. Predictors for dropout included two or three tumor nodules or a solitary lesion greater than 3 cm at initial presentation and previous hepatic resection. Our results support recent changes in the scheme of organ allocation aimed at reducing the dropout rate and improving outcome for patients with HCC awaiting OLT.

Carcinoma, Hepatocellular↗