Criteria for Paracetamol-Induced Fulminant Hepatic Failure

 

Testing: serial monitoring of the prothrombin time (PT) in the morning (with normal reference control 15 seconds)

 

Parameters:

(1) maximum PT in seconds

(2) change in PT between days 3 and 4

Parameter	Finding	Points
maximum PT	< 180 seconds	0
	>= 180 seconds	1
change in PT between days 3 and 4	decrease or stable	0
	increase (continuing rise)	1

 

where:

• Day 1 is the day after the overdose occurred (by calendar day, not 24 hour interval).

 

number of risk factors =

= SUM(points for the 2 parameters)

 

Interpretation:

• minimum score: 0

• maximum score: 2

• The higher the score the more likely the patient was to have fulminant hepatic failure.

 

Performance:

• A score of 2 was 35% sensitive but 100% specific, with a positive predictive value of 100%

• A score of 1 was 65% sensitive and 92% specific, with a positive predictive value of 89%.

• Additional testing is required to identify the other patients who develop fulminant hepatic failure who are not identified.

 

Maximum Prothrombin Time	Mortality Rate
< 90 seconds	19%
90 to 129 seconds	36%
130 to 179 seconds	49%
>= 180 seconds	92%