Low tidal volume mechanical ventilation against no ventilation during cardiopulmonary bypass heart surgery (MECANO): study protocol for a randomized controlled trial

Table 3 Flow-chart: enrollment, interventions and evaluations

		Study period
Time points^a
	Enrollment	Allocation/intervention		Post intervention			Follow up	Close out
	Preoprative visit	Before anesthesia	During surgery	Day 1	Day 2	Day 3	Day X	Hospital discharge
	(D-1 or D-2 before surgery)	Before anesthesia	During surgery	Day 1	Day 2	Day 3	Day X	Hospital discharge
Enrollment
Eligibility screen	X
Informed consent	X
Physical examination^b	X
History of previous disease^c	X
FEV (1) and FVC	X
Euroscore 2	X
Creatininemia (μmol/L)	X
Randomization		x
Intervention
Type of procedure			x
CPB (in minutes)			x
Number of red blood cell transfusions			x
Number of and reasons for manual insufflation			x
Assessments
Temperature				x	x	x
PaO2				x	x	x
FiO2				x	x	x
Ventilation mode				x	x	x
Hemoglobinemia				x	x	x
Leucocytemia				x	x	x
Quantity of bleeding				x	x	x
Collection of data on the occurrence of primary^d and secondary^e endpoints				x	x	x	x	x
Serious adverse events				x	x	x	x	x

Abbreviations: CPB cardiopulmonary bypass; D day; FiO2 fraction of inspired oxygen; PaO2 arterial oxygen tension; FEV (1) forced expiratory volume 1; FVC forced vital capacity
^aTime points: enrollment, interventions and assessments
^bPhysical examination: weight, height
^cHistory of previous disease: diabetes mellitus, peripheral arterial disease, pulmonary comorbidity, pulmonary infection in the past 30 days
^dPrimary endpoints: overall death, early respiratory failure defined as PaO2/FiO2 ratio <200 at 1 hour after arrival in the ICU, heavy oxygenation support (defined as a patient requiring either non-invasive ventilation, mechanical ventilation or high-flow oxygen) at 2 days after arrival in the ICU or ventilator-acquired pneumonia as defined by the Center of Disease Control
^eSecondary endpoints: pneumothorax, CPB duration, volume of postoperative bleeding, red blood cell transfusions, requirements for revision surgery, length of stay in the ICU and in the hospital and total hospitalization costs

ISSN: 1745-6215