Acetaminophen Overdose & Toxicology Pearls

* History: Figure out how much was taken, what time the ingestion occurred, and if any other toxins were ingested* Physical Exam: Perform a regular physical exam, and in addition, perform the toxicologic physical exam!* Check pupil size* Assess neuromuscular status for rigidity/clonus* Perform the “toxicologist handshake”* Listen to bowel sounds* Workup:* Accucheck* ECG* CBC, CMP, VBG* Acetaminophen Level (now and at four hours); Salicylate Level* UDS* Consider specific drug levels (eg digoxin, lithium, valproic acid, etc) ; consider ammonia level for valproic acid OD* Management:* ABCs first* Consider decontamination (remove clothes, hose down with water if chemical exposure, consider activated charcoal or gastric lavage for early ingestions)* Consult poison control/toxicology* Consult psychiatry if it was an attempt at self harm* Administer NAC if considered to be a “toxic ingestion of acetaminophen”* Definition of an “Acetaminophen Toxic Ingestion”* Single ingestion of acetaminophen greater than 150mg/kg* Data point on Rumack-Matthew Nomogram that is above the treatment line* If UNKNOWN amount / UNKNOWN timing of ingestion, treat if LFTs are elevated or if serum acetaminophen level is above normal limits* Rule of 150* Toxic Ingestion is considered to be a single ingestion greater than 150mg/kg* Toxic Ingestion is considered to be if the acetaminophen level at the four hour mark is >150ug/mL (this would be above the treatment line on the Rumack-Matthew Nomogrom)* Dose of NAC is 150mg/kg IV

Further Reading:

Rumack-Matthew Nomogram (MDCalc)