Flow Controlled Ventilation in Thoracic Surgery

Flow Controlled Ventilation Versus Pressure Controlled Ventilation in Thoracic Surgery With One Lung Ventilation - a Prospective, Randomized Clinical Study

This trial investigates effects of individualized (by compliance guided pressure settings) flow-controlled ventilation compared to best clinical practice pressure-controlled ventilation in thoracic surgery requiring one lung ventilation.

Flow-controlled ventilation (FCV) is a novel ventilation method with promising first results in porcine studies as well as clinical trials. A more efficient and maybe lung protective ventilation strategy would be crucial in the challenging situation of one lung ventilation during thoracic surgery, when the whole gas exchange has to be provided by just one half of the lungs. It could not only improve respiratory values, but also decrease the incidence of postoperative pulmonary complications, which is a major cause of death after thoracic surgery. Thus, individualized FCV, based on compliance guided pressure settings, will be compared to best clinical practice pressure-controlled ventilation in thoracic surgery requiring one lung ventilation in a randomized controlled trial. Based on a previous preclinical trial improved oxygenation will be expected and thus arterial partial pressure of oxygen (pO2) is the main primary outcome parameter of this study. Furthermore, improved recruitment of lung tissue due to controlled expiratory flow in FCV will be anticipated without the need of recruitment maneuvers, which may cause deleterious effects on lung tissue.

Artificial ventilation will be performed with individualized flow-controlled ventilation (Evone, Ventinova Medical B.V., Eindhoven, the Netherlands) during thoracic surgery. Individualisation will be established by compliance guided end-expiratory and peak pressure setting during double lung ventilation as well as one lung ventilation, flow setting will be adjusted to secure normocapnia and I:E Ratio set to 1:1.

Artificial ventilation will be performed with low tidal volume pressure-controlled ventilation (Primus, Dräger, Lübeck, Germany) during thoracic surgery. Peak pressure will be set to achieve a tidal volume of 7ml/kg predicted body weight at a compliance titrated positive end-expiratory pressure in double lung ventilation and 6ml/kg PBW in one lung ventilation. Respiratory rate will be set to maintain normocapnia and I:E ratio set to 1:1.5 except extension of expiration is necessary in order to avoid air trapping.

Inclusion Criteria: Male and female subjects ≥ 18 years Body weight ≥ 40 kg Size of double lumen tube ≥ 37 CH Elective thoracic surgery requiring OLV ASA I-III Written informed consent Exclusion Criteria: Emergency surgery Female subjects known to be pregnant Known participation in another interventional clinical trial high pulmonary risk (ppo FEV1<20ml/kg in male or ppo FEV1<18ml/kg in female) Empyema evacuation or signs of pulmonary infection High grade CMP (EF<30%)

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