Continuous positive airway pressure combined with small-tidal-volume ventilation on arterial oxygenation and pulmonary shunt during one-lung ventilation in patients undergoing video-assisted thoracoscopic lobectomy: A randomized, controlled study

BACKGROUND: One-lung ventilation (OLV) is frequently applied during video-assisted thoracoscopic surgery (VATS) airway management to collapse and isolate the nondependent lung (NL). OLV can give rise to hypoxemia as a result of the pulmonary shunting produced. Our study aimed to assess the influence of continuous positive airway pressure (CPAP) combined with small-tidal-volume ventilation on improving arterial oxygenation and decreasing pulmonary shunt rate (Q S /Q T ) without compromising surgical field exposure during OLV. METHODS: Forty-eight patients undergoing scheduled VATS lobectomy were enrolled in this research and allocated into three groups at random: C group (conventional ventilation, no NL ventilation intervention was performed), LP group (NL was ventilated with lower CPAP 2 cmH 2 O and a 40–60 mL tidal volume TV), and HP group (NL was ventilated with higher CPAP 5 cmH 2 O and a 60–80 mL TV). Record the blood gas analysis data and calculate the Q S /Q T at the following time: at the beginning of the OLV (T0), 30 min after OLV (T1), and 60 min after OLV (T2). Surgeons blinded to ventilation techniques were invited to evaluate the surgical fields. RESULTS: The demography data of the three groups were consistent with the surgical data. At T1, PaO 2 in the HP group was substantially higher compared to the C group ( P 0.05). At T1-T2, PaCO 2 in the LP and HP groups was significantly less than that in the C group ( P 0.05). CONCLUSION: CPAP combined with small-tidal-volume ventilation effectively improved arterial oxygenation and reduced Q S /Q T and PaCO 2 without compromising surgical field exposure during OLV. Among them, 5 cmH 2 O CPAP + 60–80 ml TV ventilation had a better effect on improving oxygenation.