Intravenous Acetaminophen After Cardiac Surgery - Definitive Study

Patients > or equal to 18 years of going for elective cardiac surgery will be randomized to receive IV either IV acetaminophen and an oral placebo acetaminophen or an IV placebo acetaminophen (saline) and oral acetaminophen every 6 hours for 48 hours after cardiac surgery. the study will be performed at 8 large Canadian cardiac surgery centres. All other therapy will be as per standard procedures (pragmatic) at the institutions including including use of their standard opioid protocol. The primary end-point is the development of delirium as assessed by Confusion Assessment Method in the Intensive Care unit (CAMICU) and the CAM on the regular floor unit for up to 7 days after surgery or discharge if it is sooner. Other measures are change from pre-operative cognitive function as assessed by the Montreal Cognitive Assessment score (MoCA) at 6 months and 1 year, numeric pain score, total opioid use, hospital and ICU length of stay. Use of opioids and pain score at 1 year also will be assessed. Patients will be stratified by site and sex.

We also will assess use of NSAID, specifically ketorolac, and any NSAID associated events.

Inclusion criteria

greater or equal to 18

• elective cardiac surgery
• stable pre-operative
• aorto-coronary bypass with or without 1 valve replacement.

Exclusion criteria

Refusal by surgeon Requested late extubation by surgeon or anesthesia Intra-aortic balloon pump Mechanical cardiac support Sensitivity to acetaminophen Psychiatric history with current active treatment Alzheimer's disease Seizure in previous 6 months Recent history of alcohol misuse Cognitive impairment

-