RESUMEN
BACKGROUND: This prospective, randomized study was to investigate whether ambient pressure oxygen administration via T-piece can be used to reduce arterial desaturation during one-lung ventilation. It can be more beneficial for thoracoscopic surgery, where partial inflation of the non-ventilated lung by continuous positive airway pressure can make the operation itself difficult, delayed, or impossible. METHODS: Patients undergoing thoracotomy (Thoracotomy group, n = 50) or video-assisted thoracoscopic surgery (VATS) (VATS group, n = 50) were enrolled into this study. Each group was further divided into two groups: control group (n = 25), and ambient pressure group (n = 25), respectively. Fifteen minutes after two-lung ventilation (TLV1) PaO2, peak inspiratory pressure, plateau pressure, and tidal volume were measured. Then, in control group, one-lung ventilation was started as usual method while in ambient pressure group, the lumen of the non-ventilated lung was connected to a T-piece with 10 L/min flow rate of oxygen. Same measurements were repeated at 15 minutes and 1 hour after one-lung ventilation (OLV1, OLV2), and 15 minutes after resuming two-lung ventilation (TLV2). Fluid input, urine output, estimated blood loss, operation side/time, and one-lung ventilation time were recorded after operation. RESULTS: In thoracotomy group, there were no significant differences in PaO2 between control group and ambient pressure group. However, in VATS group, PaO2 at OLV1 and OLV2 were significantly higher in ambient pressure group than in control group. CONCLUSIONS: In patients undergoing VATS, application of ambient pressure oxygen to the non-ventilated lung during one-lung ventilation was effective in increasing PaO2.