Table 1

Study schedule

Timepoint	Study period
	Enrolment	Baseline	Postoperative					Follow-up
	Preoperative	Day of surgery	Day 1	Day 2	Day 3	Day 4	Day 5	1 month
Enrolment
Eligibility screen	X
Entry criteria	X
Informed consent	X
Demographics	X
Medical history	X
Allocation	X
Interventions
Acetaminophen		X	X	X
Placebo		X	X	X
Assessments
MMSE	X						X
Confusion assessment method (3D-CAM/CAM-ICU)	X		X	X	X	X	X
Pain score (NRS)			X	X	X	X	X
DRS-R-98			X	X	X	X	X
Medication administration		X	X	X	X	X	X
ICU and hospital stay length							X
Unplanned readmission and mortality								X
Major postsurgical outcomes							X	X

3D-CAM, 3-min diagnostic confusion assessment method; DRS-R-98, delirium rating scale-revised-98; ICU, intensive care unit; MMSE, mini-mental state examination; NRS, numerical rating scale.