Background: One-lung ventilation (OLV) is generally adopted for thoracic surgery. The systemic application of a high fraction of inspiratory oxygen (F<sub>1</sub>O<sub>2</sub>) and continuous p...Background: One-lung ventilation (OLV) is generally adopted for thoracic surgery. The systemic application of a high fraction of inspiratory oxygen (F<sub>1</sub>O<sub>2</sub>) and continuous positive airway pressure (CPAP) to the non-ventilated lung is useful for preventing arterial oxygen desaturation. The adverse effects of elevated F<sub>1</sub>O<sub>2</sub> include oxidative lung injury, resorption atelectasis and coronary and peripheral vasoconstriction. It is preferable to avoid hyperoxemia in patients with complications such as chronic obstructive pulmonary disease, idiopathic pneumonia, and bleomycin-treated lungs. We aimed to determine whether the application of 60% O<sub>2</sub> CPAP to the non-ventilated lung is sufficient to provide adequate oxygenation with 60% O<sub>2</sub> to the ventilated lung. Methods: A total of 70 patients scheduled to receive elective thoracic surgery requiring OLV were recruited. Left double-lumen tubes were applicable in all surgeries. Patients were randomly allocated to one of two groups, to receive either 60% O<sub>2</sub> CPAP (60% CPAP group, n = 35), or 100% O<sub>2</sub> CPAP (100% CPAP group, n = 35) at a setting of 2 - 3 cmH<sub>2</sub>O, applied to the non-ventilated lung. Arterial blood gas analyses were obtained at the following stages: RA, spontaneous breathing under room air (RA);TLV, during total lung ventilation (TLV) prior to the initiation of OLV;T5, 5 min after the initiation of OLV;T15, 15 min after the initiation of OLV;T30, 30 min after the initiation of OLV. Results: The PaO<sub>2</sub> value in 60% CPAP group vs. 100% CPAP group at each measurement were as follows: RA (mean [standard deviation: SD], 89.7 [8.2] mmHg vs. 85.8 [11.9] mmHg);TLV (277.9 [52.9] mmHg vs. 269.2 [44.0] mmHg);T5 (191.4 [67.9] mmHg vs. 192.3 [66.0] mmHg);T15 (143.2 [67.3] mmHg vs. 154.7 [60.8] mmHg) and T30 (95.6 [32.0] mmHg vs. 112.5 [36.5] mmHg), respectively. Among the five measurement points, T30 was the only time point at which the 100% CPAP group showed a significantly greater PaO<sub>2</sub> value than the 60% CPAP group (p = 0.0495). The SaO<sub>2</sub> at T30 in the 100% CPAP group (97.4 [2.0]%) was also significantly greater than that in the 60% CPAP group (96.3 [2.2]%, p = 0.039). No differences were found between the groups regarding changes to the overall PaO<sub>2</sub> values (p = 0.44) and SaO<sub>2</sub> values (p = 0.23) during the study period. Conclusions: Oxygenation could be safely maintained in relatively healthy patients with 60% O<sub>2</sub> OLV and 60% O<sub>2</sub> CPAP. The application of 60% O<sub>2</sub> CPAP during OLV for patients who are not suited to exposure to high F<sub>1</sub>O<sub>2</sub> may be an alternative form of respiratory management.展开更多
文摘Background: One-lung ventilation (OLV) is generally adopted for thoracic surgery. The systemic application of a high fraction of inspiratory oxygen (F<sub>1</sub>O<sub>2</sub>) and continuous positive airway pressure (CPAP) to the non-ventilated lung is useful for preventing arterial oxygen desaturation. The adverse effects of elevated F<sub>1</sub>O<sub>2</sub> include oxidative lung injury, resorption atelectasis and coronary and peripheral vasoconstriction. It is preferable to avoid hyperoxemia in patients with complications such as chronic obstructive pulmonary disease, idiopathic pneumonia, and bleomycin-treated lungs. We aimed to determine whether the application of 60% O<sub>2</sub> CPAP to the non-ventilated lung is sufficient to provide adequate oxygenation with 60% O<sub>2</sub> to the ventilated lung. Methods: A total of 70 patients scheduled to receive elective thoracic surgery requiring OLV were recruited. Left double-lumen tubes were applicable in all surgeries. Patients were randomly allocated to one of two groups, to receive either 60% O<sub>2</sub> CPAP (60% CPAP group, n = 35), or 100% O<sub>2</sub> CPAP (100% CPAP group, n = 35) at a setting of 2 - 3 cmH<sub>2</sub>O, applied to the non-ventilated lung. Arterial blood gas analyses were obtained at the following stages: RA, spontaneous breathing under room air (RA);TLV, during total lung ventilation (TLV) prior to the initiation of OLV;T5, 5 min after the initiation of OLV;T15, 15 min after the initiation of OLV;T30, 30 min after the initiation of OLV. Results: The PaO<sub>2</sub> value in 60% CPAP group vs. 100% CPAP group at each measurement were as follows: RA (mean [standard deviation: SD], 89.7 [8.2] mmHg vs. 85.8 [11.9] mmHg);TLV (277.9 [52.9] mmHg vs. 269.2 [44.0] mmHg);T5 (191.4 [67.9] mmHg vs. 192.3 [66.0] mmHg);T15 (143.2 [67.3] mmHg vs. 154.7 [60.8] mmHg) and T30 (95.6 [32.0] mmHg vs. 112.5 [36.5] mmHg), respectively. Among the five measurement points, T30 was the only time point at which the 100% CPAP group showed a significantly greater PaO<sub>2</sub> value than the 60% CPAP group (p = 0.0495). The SaO<sub>2</sub> at T30 in the 100% CPAP group (97.4 [2.0]%) was also significantly greater than that in the 60% CPAP group (96.3 [2.2]%, p = 0.039). No differences were found between the groups regarding changes to the overall PaO<sub>2</sub> values (p = 0.44) and SaO<sub>2</sub> values (p = 0.23) during the study period. Conclusions: Oxygenation could be safely maintained in relatively healthy patients with 60% O<sub>2</sub> OLV and 60% O<sub>2</sub> CPAP. The application of 60% O<sub>2</sub> CPAP during OLV for patients who are not suited to exposure to high F<sub>1</sub>O<sub>2</sub> may be an alternative form of respiratory management.
