Acute acetaminophen intoxication in Taiwan: outcomes and risk factors.

BACKGROUND AND PURPOSE

There is a paucity of information about acetaminophen intoxication from Taiwan. This study investigated the outcome and risk factors for acetaminophen-induced hepatotoxicity and validated the Rumack- Matthew nomogram in Taiwanese patients with acute acetaminophen intoxication.

METHODS

A total of 75 patients with acetaminophen intoxication admitted through the emergency department were included in this retrospective analysis. Patients with a serum acetaminophen concentration above the possible risk line on the nomogram were treated with oral N-acetylcysteine. The primary outcome measure was the development of major hepatotoxicity, which was defined as a serum aminotransferase concentration greater than 1000 IU/L. Patient outcomes in the possible risk group and probable risk group were plotted on the modified Rumack-Matthew nomogram for validation. The risk factors for acetaminophen-induced hepatotoxicity were identified by multiple logistic regression analysis.

RESULTS

No hepatotoxicity developed in patients with an initial acetaminophen concentration below the possible risk line on the nomogram. One out of 8 patients in the possible risk group developed major hepatotoxicity; 8 out of 22 patients in the probable risk group developed major hepatotoxicity, representing an incidence of 12.5% and 36.4%, respectively. Patients in the major hepatotoxicity group were older (32.5 vs 24.2 years, p = 0.019), and had a longer time to presentation (28.1 vs 6.7 hours, p < 0.01) than those in the non/minor hepatotoxicity group. Multiple logistic regression revealed that age and time to presentation were independent risk factors for hepatotoxicity (p = 0.033 and p = 0.002, respectively).

CONCLUSIONS

The results of outcome analysis confirm that the modified Rumack-Matthew nomogram has a high sensitivity for identifying Taiwanese patients at risk for acetaminophen-induced hepatoxicity. Patient age and time to presentation were independent risk factors for acetaminophen-induced hepatotoxicity.