investigations

Last reviewed 01/2018

In a case of suspected paracetamol poisoning an emergency blood level should be taken, at least 4 hrs after ingestion.

The first sign of hepatic necrosis is prolongation of the prothrombin time:

• a prothrombin time > 45 sec indicates severe liver damage
• potentially fatal overdoses cause maximal derangement of the clotting system after 72 hr
• a prothrombin time > 25 sec after 46 hr is prognostically ominous