Table 1.

Perioperative Ventilation Protocol in Each of the Two Strategies

	Control Ventilation	Open-lung Ventilation
Ventilation before CPB	Tidal volume 6–8 ml/kg of predicted body weight	Tidal volume 6–8 ml/kg of predicted body weight
	PEEP 2 cm H2O	PEEP 8 cm H2O
	RR for ETCO2 35–45 mmHg	RR for ETCO2 35–45 mmHg
	Lowest Fio2 for Spo2 greater than 94%	Lowest Fio2 for Spo2 greater than 94%
	I:E ratio at 1:2	I:E ratio at 1:2
Systematic recruitment maneuvers	No	Yes*
Ventilation during CPB	No	Yes
	Continuous positive airway pressure = 2 cm H2O	Tidal volume 3 ml/kg of predicted body weight
	Fio2 40%	PEEP 8 cm H2O
		RR 12 cycles per minute
		Fio2 40%
Ventilation after CPB (including in ICU)	Tidal volume 6–8 ml/kg of predicted body weight	Tidal volume 6–8 ml/kg of predicted body weight
	PEEP 2 cm H2O	PEEP 8 cm H2O
	RR for ETCO2 35–45 mmHg	RR for ETCO2 35–45 mmHg
	Lowest Fio2 for Spo2 greater than 94%	Lowest Fio2 for Spo2 greater than 94%
	I:E ratio at 1:2	I:E ratio at 1:2

cm H₂O, centimeter of water; CPB, cardiopulmonary bypass; ETCO₂, end-tidal CO₂; Fio₂, inspired oxygen fraction, I:E inspiratory time to expiratory time ratio; ICU, intensive care unit; PEEP, positive end-expiratory pressure; RR respiratory rate; Spo₂, oxygen saturation as detected by the pulse oximeter.

^*Continuous airway pressure at 30 cm of water for 30 s. Recruitment maneuvers were planed after orotracheal intubation, at CPB initiation, at aortic unclamping after de-airing maneuvers, at ICU arrival, and after every breathing circuit disconnection.