The effect of supplemental oxygen on perioperative brain natriuretic peptide concentration in cardiac risk patients – a protocol for a prosprective randomized clinical trial

Table 2 Schedule of study events

Timepoints		Study period
	Enrollment	Intervention			Postoperative period			Close out
	Preoperative visit	Before anesthesia	During surgery	End of surgery for 2 h after surgery	POD 1	POD 3	Hospital discharge	POD telephone follow-up
*Enrollment*
Eligibility screening	X
Informed consent	X
Patient history	X
Allocation		X
*Intervention*
80% inspired oxygen			X
30% inspired oxygen			X
Anesthesia/surgery variables			X
80% via face mask				X
30% via face mask				X
Adverse events			X	X
*Assessments*
Outcomes (see Table 1)					X	X	X
Adverse events					X	X	X	X

ISSN: 1745-6215