Comparison of the efficacy of high-flow oxygen insufflations and continuous positive airway pressure during one-lung ventilation undergoing video-assisted thoracoscopic surgery
Authors: Farshatov A. G. , Ershov E. N. , Shchegolev A. V. 
Published: June 2023

Isolation of one-lung leads to ventilation-perfusion mismatch and increases intrapulmonary shunt, which in some cases may lead to clinically significant hypoxemia.

The objective was to compare the efficacy of hypoxemia correction and the convenience of surgical work during one-lung ventilation with the use of high-flow oxygen insufflation (HFI) and continuous positive airway pressure (CPAP) in the non-ventilated lung during video-assisted thoracoscopic surgery (VATS).

Materials and methods. The study included 60 patients who underwent surgical intervention in the form of VATS lobectomy. All studied patients were randomly divided into two groups: group 1 included patients who received HFI into non-ventilated lung to correct hypoxemia, and group 2 – CPAP into non-ventilated lung. The study was divided into four stages. Stage I – two-lung ventilation. Stage II – one-lung ventilation. At stage III, HFI of 60 L/min (FiO2 = 0,5) into non-ventilated lung was used to correct hypoxemia in group 1, and CPAP of 5 cm H2O into non-ventilated lung was used in group 2. At stage IV, HFI of 30 L/min (FiO2 = 0,5) into non-ventilated lung was used to correct hypoxemia in group 1, and CPAP of 2 cm H2O into non-ventilated lung was used in group 2. The following parameters were recorded during the stages of the study: PaO2, PaCO2, SpO2, Qs/Qt, and surgical team satisfaction with lung collapse by 10-point visual analogue scale (VAS).

Results. At stages I and II, there was no statistically significant difference between groups in such parameters as PaO2, PaCO2, SaO2, and SpO2 (p > 0.05). Starting from stage III, a statistically significant difference between the two groups was found for a parameter PaO2 (U 26.0; Z = –6.27; p < 0.001). For group 1, it was equal to 134.5 (126.0; 141.75) and for group 2 – 108.5 (104.0; 114.5) correspondingly. At stage IV, the values of PaO2 were higher in group 1: 118.5 (113.0; 122.25) vs 92.5 (89.0; 98.25) in group 2 (U 0.0; Z = –6.66; p < 0.001). When comparing PaCO2 between the two groups, there were no statistically significant differences at all stages (p > 0.35). When comparing SaO2 at stages I (U 450.0; Z = 0.0; p = 1.0), II (U 422.5; Z = –0.4; p = 0.69), III (U 339.0; Z = –1.8; p = 0.69), no statistically significant differences were indicated between the two groups. However, at stage IV, the value of SaO2 was higher (97 (96; 97)) in group 1 than in group 2 (94 (94; 95)), U 69.5; Z = –5.75; p < 0.001. When comparing SpO2 between the two groups, there was no statistical difference at all stages (p > 0.69). Comparing the two groups by such indicator as Qs/Qt, no statistically significant differences were found at the first three stages (p > 0.4). A comparison of Qs/Qt at stage IV revealed statistically significant differences (U 69.0; Z = –5.6; p < 0.001). This parameter was equal to 10.7% (9.5; 15.7) in group 1 and 21.3% (18.4; 23.9) in group 2 correspondingly. When assessing surgical team satisfaction levels with surgical field visualization by VAS, there were statistically significant differences between group 1 and group 2 at stage III (p < 0.001) and stage IV (p < 0.001). The satisfaction level was significantly higher in group 1.

Conclusions. The usage of high-flow oxygen insufflation during one-lung ventilation undergoing VATS allows to effectively correcting hypoxemia similar to the CPAP method, but as opposed to CPAP, it can provide comfortable conditions for carrying out the surgical procedures.