Factor V and factor VIII:V ratio as prognostic indicators in paracetamol poisoning

Pattern of Paracetamol Poisoning: Influence on Outcome and Complications

Acute paracetamol poisoning due to a single overdose may be effectively treated by the early administration of N-acetylcysteine (NAC) as an antidote. The prognosis may be different in the case of intoxication due to multiple ingestions or when the antidote is started with delay. The aim of this work was to investigate the outcome of paracetamol poisoning according to the pattern of ingestion and determine the factors associated with the outcome. We performed a retrospective analysis over the period 2007–2017 of the patients who were referred to a tertiary hospital for paracetamol-related hepatotoxicity. Inclusion criteria were: accidental or voluntary ingestion of paracetamol, delay for NAC therapy of 12 h or more, liver enzymes (ALT) >1000 IU/L on admission. Ninety patients were considered. Poisoned patients following multiple ingestion were significantly older (45 ± 12 vs. 33 ± 14) (p = 0.001), with a higher incidence of liver steatosis (p = 0.016) or chronic ethanol abuse (p = 0.04). In comparison with the subgroup of favorable outcome, the patients with poor outcome were older, had higher values for ALT, bilirubin, lactate, and lower values for factor V and arterial pH. In multivariate analysis, the arterial lactate value was associated with a bad prognosis (p < 0.02) (adjusted odds ratio 1.74 and CI 95:1.09–2.77). The risk of poor outcome was greater in the subgroup with staggered overdose (p = 0.02), which had a higher mortality rate (p = 0.01). This retrospective analysis illustrates the different population patterns of patients who were admitted for a single ingestion of a paracetamol overdose versus multiple ingestions. This last subgroup was mainly represented by older patients with additional risk factors for hepatotoxicity; arterial lactate was a good predictor of severity.

Fulminant hepatic failure secondary to acetaminophen poisoning: a systematic review and meta-analysis of prognostic criteria determining the need for liver transplantation

OBJECTIVES

To summarize and compare different prognostic criteria used to determine need for liver transplantation in patients with fulminant hepatic failure secondary to acetaminophen poisoning.

DATA SOURCES

Studies published in the literature that investigated criteria for hepatic transplantation secondary to acetaminophen-induced liver failure as identified by a preestablished MEDLINE strategy (1966 through October 2001).

STUDY SELECTION

Studies were included if 2 x 2 tables could be reconstructed and if they did not assume that patients undergoing transplantation would have eventually died had they not received the transplant.

DATA EXTRACTION

Relevant articles were reviewed by two authors independently. Discrepancies or disagreements, if any, on the inclusion or exclusion of studies were resolved by consulting the third author.

DATA SYNTHESIS

King's criteria (pH < 7.30 or prothrombin time of >100 secs plus creatinine of >300 micromol/L plus encephalopathy grade of > or =3) were evaluated in nine studies, pH < 7.30 in four, prothrombin time of >100 secs in three, prothrombin time of >100 secs plus creatinine of >300 micromol/L plus encephalopathy grade of > or =3 in three, creatinine of >300 micromol/L in two, and one each for increase in prothrombin time day 4, factor V of <10%, Acute Physiology and Chronic Health Evaluation (APACHE) II score of >15, and Gc-globulin of <100 mg/L. King's criteria were more sensitive than pH: 69% (95% confidence interval, 63-75) vs. 57% (95% confidence interval, 44-68). Their specificities were, however, comparable: 92% (95% confidence interval, 81-97) vs. 89% (95% confidence interval, 62-97). APACHE II score of >15 had the highest positive likelihood ratio (16.4) and the lowest negative likelihood ratio (0.19) but was evaluated in only one study. The accuracy measures of all other criteria were lower than that of King's criteria or pH < 7.30.

CONCLUSIONS

Presently, available criteria are not very sensitive and may miss patients requiring transplantation. Future studies should further evaluate the efficacy of the APACHE II criteria.

Paracetamol poisoning in children

Paracetamol (acetaminophen) has become an antipyretic drug of choice. Due to its widespread use, toxicity secondary to overdose has increased in recent years. Children are especially vulnerable to accidental exposure due to non availability of child proof containers in India. The main clinical features of acute toxicity include anorexia, vomiting, abdominal pain, jaundice, hematuria and metabolic acidoses. Diagnosis is based on history and laboratory findings of acidosis and abnormal liver function tests. N-acetylcysteine is the specific antidote. This article reviews in detail the toxicokinetics, pathophysiology, clinical features and management of paracetamol poisoning in children.