Differential lung ventilation for increased oxygenation during one lung ventilation for video assisted lung surgery

BACKGROUND: One lung ventilation (OLV) is the technique used during lung resection surgery in order to facilitate optimal surgical conditions. OLV may result in hypoxemia due to the shunt created. Several techniques are used to overcome the hypoxemia, one of which is continuous positive airway pressure (CPAP) to the non-dependent lung. Another technique is ventilating the non-dependent lung with a minimal volume, thus creating differential lung ventilation (DLV). In this study we compared the efficacy of CPAP to DLV during video assisted thoracoscopic lung resection. PATIENTS AND METHOD: This is a prospective study of 30 adult patients undergoing elective video assisted thoracoscopic lung lobectomy. Each patient was ventilated in four modes: two lung ventilation, OLV, OLV + CPAP and OLV + DLV. Fifteen patients were ventilated with CPAP first and DLV next, and the other 15 were ventilated with DLV first and then CPAP. Five minutes separated each mode, during which the non-dependent lung was open to room air. We measured the patient’s arterial blood gas during each mode of ventilation. The surgeons, who were blinded to the ventilation technique, were asked to assess the surgical conditions at each stage. RESULTS: Oxygenation during OLV+ CPAP was significantly lower that OLV + DLV (p = 0.018). There were insignificant alterations of pH, PCO2 and HCO3 during the different ventilating modes. The surgeons’ assessments of interference in the field exposure between OLV + CPAP or OLV + DLV was found to be insignificant (p = 0.073). CONCLUSIONS: During OLV, DLV is superior to CPAP in improving patient’s oxygenation, and may be used where CPAP failed. TRIAL REGISTRATION: ClinicalTrials.gov NCT03563612. Registered 9 June 2018, retrospectively (due to clerical error).