Prothrombin time to assess fulminant hepatic failure

Ability of King's College Criteria and Model for End-Stage Liver Disease Scores to Predict Mortality of Patients With Acute Liver Failure: A Meta-analysis

BACKGROUND & AIMS

Several prognostic factors are used to identify patients with acute liver failure (ALF) who require emergency liver transplantation. We performed a meta-analysis to determine the accuracy of King's College criteria (KCC) versus the model for end-stage liver disease (MELD) scores in predicting hospital mortality among patients with ALF.

METHODS

We performed a systematic search of the literature for articles published from 2001 through 2015 that compared the accuracy of the KCC with MELD scores in predicting hospital mortality in patients with ALF. We identified 23 studies (comprising 2153 patients) and assessed the quality of data, and then performed a meta-analysis of pooled sensitivity and specificity values, diagnostic odds ratios (DORs), and summary receiver operating characteristic curves. Subgroups analyzed included study quality, era, location (Europe vs non-Europe), and size; ALF etiology (acetaminophen-associated ALF [AALF] vs nonassociated [NAALF]); and whether or not the study included patients who underwent liver transplantation and if the study center was also a transplant center.

RESULTS

The DOR for the KCC was 5.3 (95% confidence interval [CI], 3.7-7.6; 57% heterogeneity) and the DOR for MELD score was 7.0 (95% CI, 5.1-9.7; 48% heterogeneity), so the MELD score and KCC are comparable in overall accuracy. The summary area under the receiver operating characteristic curve values was 0.76 for the KCC and 0.78 for MELD scores. The KCC identified patients with AALF who died with 58% sensitivity (95% CI, 51%-65%) and 89% specificity (95% CI, 85%-93%), whereas MELD scores identified patients with AALF who died with 80% sensitivity (95% CI, 74%-86%) and 53% specificity (95% CI, 47%-59%). The KCC predicted hospital mortality in patients with NAALF with 58% sensitivity (95% CI, 54%-63%) and 74% specificity (95% CI, 69%-78%), whereas MELD scores predicted hospital mortality in patients with NAALF with 76% sensitivity (95% CI, 72%-80%) and 73% specificity (95% CI, 69%-78%). In patients with AALF, the KCC's DOR was 10.4 (95% CI, 4.9-22.1) and the MELD score's DOR was 6.6 (95% CI, 2.1-20.2). In patients with NAALF, the KCC's DOR was 4.16 (95% CI, 2.34-7.40) and the MELD score's DOR was 8.42 (95% CI, 5.98-11.88).

CONCLUSIONS

Based on a meta-analysis of studies, the KCC more accurately predicts hospital mortality among patients with AALF, whereas MELD scores more accurately predict mortality among patients with NAALF. However, there is significant heterogeneity among studies and neither system is optimal for all patients. Given the importance of specificity in decision making for listing for emergency liver transplantation, MELD scores should not replace the KCC in predicting hospital mortality of patients with AALF, but could have a role for NAALF.

The sequential organ failure assessment (SOFA) score is prognostically superior to the model for end-stage liver disease (MELD) and MELD variants following paracetamol (acetaminophen) overdose

BACKGROUND

The prognostic value of the model for end-stage liver disease (MELD) and sodium-based MELD variants in predicting survival following paracetamol overdose remains unclear.

AIM

To examine the prognostic accuracy of sodium-based MELD variants in paracetamol-induced acute liver injury compared with the sequential organ failure assessment (SOFA) score.

METHODS

Retrospective analysis of 138 single time point paracetamol overdoses admitted to a tertiary liver centre. Individual laboratory samples were correlated with the corresponding clinical parameters in relation to time post-overdose, and the daily MELD, MELD-Na, MELDNa, MESO, iMELD, UKELD, updated MELD and SOFA scores were calculated.

RESULTS

Sixty-six (47.8%) patients developed hepatic encephalopathy, of whom 7 were transplanted and 21 died without liver transplantation. SOFA had a significantly greater area under the receiver operator characteristic for the prediction of spontaneous survival compared with MELD at both 72 (P = 0.024) and 96 (P = 0.017) h post-overdose. None of the sodium-based MELD variants improved the prognostic accuracy of MELD. A SOFA score >6 by 72 h or >7 by 96 h, post-overdose predicted death/transplantation with a negative predictive value of 96.9 (95% CI 90.2-99.4) and 98.8 (95% CI 93.6-99.9) respectively. SOFA and MELD had similar accuracy for predicting the development of hepatic encephalopathy (P = 0.493).

CONCLUSIONS

The SOFA score is superior to MELD in predicting spontaneous survival following paracetamol-induced acute liver injury. Modification of the MELD score to include serum sodium does not improve prognostic accuracy in this setting. SOFA may have potential as a quantitative triage marker following paracetamol overdose.

The utilization of liver transplantation in the management of acute liver failure: comparison between acetaminophen and non-acetaminophen etiologies

Liver transplantation (LT) may be life-saving in severe acute liver failure (ALF). The aim of this study was to compare the utilization of LT in acetaminophen and non-acetaminophen ALF. Between 1992 and 2006, 469 patients with ALF were admitted, and 104 underwent LT. Acetaminophen was the most common etiology, but LT proceeded more frequently in the non-acetaminophen cohort (acetaminophen: 45/326 patients received LT, 13.8%; non-acetaminophen: 59/143 patients received LT, 41.3%; P < 0.01). A retrospective analysis of the individual steps in the management of patients revealed more ALF patients in the non-acetaminophen cohort fulfilled the King's College Hospital poor prognostic criteria (non-acetaminophen: 91/143, 63.6%; acetaminophen: 165/326, 50.6%; P < 0.01), more patients had contraindications to LT in the acetaminophen cohort (acetaminophen: 99/165, 60%; non-acetaminophen: 21/91, 23.1%; P < 0.01), and survival on the LT waiting list was reduced in the acetaminophen cohort (acetaminophen: 45/66, 68.2%; non-acetaminophen: 59/70, 84.3%; P < 0.05). Post-LT survival was similar in the 2 groups. An analysis of cohorts admitted in 1993-1996 and 2002-2005 revealed that LT proceeded less commonly in acetaminophen ALF in the later cohort (1993-1996: 16/99 LT, 16.2%; 2002-2005: 4/81 LT, 5%; P < 0.01) in comparison with the non-acetaminophen cohort, in which transplantation proceeded more commonly in the later cohort (1993-1996: 11/34 LT, 32.4%; 2002-2005: 24/49 patients, 49.0%; P < 0.01). This was due to an increase in the number of patients with psychiatric contraindications to transplantation (predominantly resistant and severe alcohol dependence). In conclusion, at all decision steps between admission and emergency LT, LT is favored in non-acetaminophen patients, and nonoperative management is favored in acetaminophen ALF patients.

A biochemical prognostic model of outcome in paracetamol-induced acute liver injury

BACKGROUND

The aim of this study was to develop a prognostic model of outcome for patients with paracetamol induced acute liver injury based on admission parameters

METHODS

We used a cohort of 97 patients admitted to the Scottish Liver Transplant Unit between 1997 and 1998 to identify biochemical prognostic markers of outcome and thus create a prognostic model. Blood samples were taken on admission for analysis. The model was subsequently validated by testing it on a second cohort of 86 patients admitted between 1999 and 2000.

RESULTS

The following were identified as independent variables of poor prognosis (death/ transplant); phenylalanine, pyruvate, alanine, acetate, calcium, haemoglobin and lactate. A prognostic model was then constructed by stepwise forward logistic regression analysis: (400xPyruvate mmols/L)+(50xPhenylalanine (mmols/L)-(4 x Hemoglobin (g/dL). A value of <16 had an accuracy of 93% in predicting death correctly. When applied to the validation cohort this model had a positive predictive value of 91%, a negative predictive value of 94%, a sensitivity of 91%, and a specificity of 94%. On the same population overall, the positive and negative predictive value of the King's criteria were 94% and 93% respectively, whereas their sensitivity and specificity were 88% and 96% respectively.

CONCLUSIONS

Using admission characteristics our model is able to identify patients who die from paracetamol overdose fulminant hepatic failure as accurately as King's College criteria, but at a much earlier stage in their condition.