INTELLiVENT-ASV Using Mainstream Versus Sidestream End-Tidal CO2 Monitoring

Background INTELLiVENT-ASV, an automated closed-loop mode of mechanical ventilation, available on Hamilton ventilators for clinical use, uses mainstream end-tidal CO2 (etCO2) monitoring to adjust minute ventilation. However, sensors for mainstream etCO2 monitoring are expensive and fragile. The less expensive and more robust sensors for sidestream etCO2 monitoring could serve as a good alternative to sensors for mainstream etCO2 monitoring. Objective of the study The objective of this randomized noninferiority trial is to determine whether INTELLiVENT- ASV with sidestream capnography is noninferior to INTELLiVENT-ASV with mainstream capnography with regard to the percentage of breaths in a broadly accepted predefined 'optimal' zone of ventilation. Hypothesis The investigators hypothesize that INTELLiVENT-ASV with sidestream capnography is noninferior to INTELLiVENT-ASV with mainstream capnography with respect to the percentage of breaths a patient spends within the 'optimal' zone of ventilation. Study design INTELLiSTREAM is a randomized noninferiority study. Study population The study population consists of consecutive elective cardiac surgery patients who are expected to need at least 2 hours of postoperative ventilation in the ICU of Amsterdam Medical University Centers, location 'AMC'. Intervention Shortly after arrival at the ICU, patients will be randomized to receive either ventilation with INTELLiVENT-ASV with mainstream capnography or sidestream capnography. Primary outcome of the study The primary study endpoint is the percentage of breaths a patient spends inside the 'optimal' zone of ventilation, as defined before (i.e. tidal volume \< 10 ml/kg PBW, maximum airway pressure \< 30cm H2O, etCO2 between 30-46 mmHg and pulse oximetry between 93-98%). Secondary outcomes The percentage of time spent in other ventilation zones, as defined in the protocol. Time to spontaneous breathing, duration of weaning, loss of etCO2 signal, duration of postope