Abstract
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), while there was no significant difference in the LP 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). At T1, the Q(S)/Q(T) values of groups C, LP, and HP were 29.54 ± 6.89%, 22.66 ± 2.08%, and 19.64 ± 5.76%, respectively, and the Q(S)/Q(T) values in the LP and HP groups markedly reduced (P < 0.01). The surgical field's evaluation by the surgeon among the three groups was not notable (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.