Can we improve prognostic indications in acetaminophen-induced hepatic failure?

February 9, 2018, 4:13 pm

★★½☆☆

Hypoglycemia and lactic acidosis outperform King’s College criteria for predicting death or transplant in acetaminophen toxic patients. Levine M et al. Clin Toxicol 2018 Jan 5 [Epub ahead of print]

Abstract

The standard tool used in evaluating acetaminophen-poisoned patients for possible orthotopic liver transplantation (OLT) is the King’s College Criteria (KCC).

The KCC identify 2 groups of patients who are expected to have a poor prognosis after overdosing on acetaminophen:

arterial pH < 7.30 after resuscitation

OR

INR > 6.5 (PT > 100 sec)
AND
serum creatinine > 3.4 mg/dl
AND
Hepatic encephalopathy (Grade III or IV)

Some versions of KCC also include lactic acidosis as a poor prognostic indicator.

It’s important to take note of the limitations inherent in the KCC. It was derived in the 1980s, which means modern advances in use of N-acetylcysteine and standard ICU care were not available. All patients were evaluated and treated at King’s College Hospital in London, bringing into question whether the results are generalizable to other centers. In addition, inclusion of advanced hepatic encephalopathy as a criterion for OLT means that some patients may be too sick for surgery by the time they qualify.

This multi-center retrospective cohort study looked at adult patients (> 14 years old) admitted to hospital and discharged with a diagnosis of acetaminophen-induced liver failure. The objective was to compare the markers of hypoglycemia (glucose < 50 mg/dL,) coagulopathy, and lactic acidosis (lactate above hospital’s “normal” range) in predicting a composite endpoint of death or liver transplantation.

The authors identified 334 unique cases. 19 of these were listed for transplant, and 13 actually received liver transplant. (2 transplanted patients subsequently died.) Although 96 patients (29%) met the King’s College Criteria, it is not clear how many of these who were not transplanted died. There were 40 deaths in all.

After some statistical manipulation  which was not at all nearly described, the authors conclude that:

The combination of hypoglycemia, coagulopathy, and lactic acidosis performed better than the King’s College criteria for predicting death or transplant.

I’d submit that “better” is really a helpful word in describing the permanence of these dueling criteria. Despite reading the paper several times, I could not tell exactly what the authors meant by “better.” In any case, I don’t think this study design could have met their objectives even for the purpose of a pilot study. The composite endpoint muddles everything. True, death is a firm, obvious outcome, but the decision to transplant is subjective, and certainly based in part on some of the criteria being tested.

 

 

 

 

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