Dr Lars E Schmidt and K Dalhoff from the Departments of Hepatology and Clinical Pharmacology at the Rigshospitalet in Copenhagen, Denmark, present their findings in the latest issue of the journal.
They studied patients 602 patients who had been transferred to a specialized unit with severe paracetamol poisoning, along with 212 unselected patients admitted from the local region, to discover the incidence, clinical characteristics and prognostic implications of hyperamylasaemia in such patients.
The retrospective study was based on hospital charts, with the optimum threshold of serum amylase to discriminate non-survivors being identified.
An elevated serum amylase (>100 U/L) occurred in 28 of the unselected patients (13%), in 218 of the transferred patients (36%), and in 118 of 148 patients (80%) with fulminant hepatic failure.
Only 33 cases of paracetamol-associated acute pancreatitis were diagnosed.
A threshold serum amylase of 150 U/L to discriminate non-survivors had sensitivity 76%, specificity 85%, positive predictive value 33%, and negative predictive value 97%.
In a logistic regression analysis, a serum amylase of greater than 150 U/L was associated with an excess mortality.
Dr Schmidt said that the study showed, "Hyperamylasaemia is frequent in patients with paracetamol poisoning, whereas clinical acute pancreatitis occurs rarely."
He added, "The incidence of hyperamylasaemia increases with the degree of hepatic dysfunction. A serum amylase exceeding 1.5 times the upper normal limit indicates a poor prognosis."