ABSTRACT
Objective:To compare the effects of volume-controlled ventilation (VCV),pressure-controlled ventilation (PCV) and pressure controlled ventilation-volume guarantee (PCV-VG) on respiratory mechanics and respiratory function index in patients undergoing endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).Methods:Seventy-five patients who underwent EBUS-TBNA under general anesthesia during February to December in 2019 in Lishui City People's Hospital,China were included in this study.They were randomly assigned to undergo VCV (Group V),PCV (Group P) or PCV-VG (Group G),with 25 patients in each group during EBUS-TBNA.After exclusion because of different reasons,25,24 and 24 patients from the Groups V,P and G respectively were included in the final analysis.Peak airway pressure (P peak),pulmonary dynamic compliance (C dyn),the partial pressure of carbon dioxide in arterial blood (PaCO 2),and oxygenation index (OI) at baseline (T 0),at the time of EBUS-TBNA for 30 (T 1) and 60 min (T 2) and immediately after EBUS-TBNA (T 3). Results:At T 2 and T 3,P peak in the Group P was (22.5 ±5.2) cmH 2O and (16.2 ± 2.8) cmH 2O respectively,which was significantly lower than that in the Group V [(25.8 ± 3.5) cmH 2O,(18.2 ± 3.2) cmH 2O, q = 3.672,3.454, P = 0.031,0.045).At T 1,T 2 and T 3,C dyn in the Group P was (26.4 ± 5.0) mL/cmH 2O,(24.1 ± 4.5) mL/cmH 2O and (32.5 ± 4.2) mL/cmH 2O,respectively,which was significantly higher than that in the Group V [(23.0 ± 2.7) mL/cmH 2O,(19.9 ± 2.1) mL/cmH 2O,(28.5 ± 3.7) mL/cmH 2O, q = 3.732,4.795,4.118, P = 0.027,0.004,0.013).At T 2 and T 3,P peak in the Group G was (21.7 ± 4.3) cmH 2O,(15.6 ± 2.6) cmH 2O,respectively,which was significantly lower than that in the Group V [(25.8 ± 3.5) cmH 2O,(18.2 ± 3.2) cmH 2O, q = 4.493,4.332, P = 0.006,0.009]. At T 1,T 2,and T 3,C ydn in the Group G was (26.6 ± 5.6) mL/cmH 2O,(24.3 ± 5.6) mL/cmH 2O,(33.2 ± 6.3) mL/cmH 2O,which was higher than that in the Group V [(23.0 ± 2.7) mL/cmH 2O,(19.9 ± 2.1) mL/cmH 2O,(28.5 ± 3.7) mL/cmH 2O, q = 3.852,4.936,4.791, P = 0.022,0.002,0.003]. At T 2 and T 3,PaCO 2 in the Group G was (41.1 ± 3.8) mmHg,(38.4 ± 3.4) mmHg,respectively,which was significantly lower than that in the group V [(45.7 ± 3.4) mmHg,(41.0 ± 3.0) mmHg, q = 5.969,3.682, P = 0.000,0.030].At T 2,OI in the group G was significantly higher than that in the group V [(358.0 ± 32.8) mmHg vs.(326.6 ± 29.7) mmHg, q = 4.782, P = 0.030].There were no significant differences in indexes between groups P and G (all P>0.05). Conclusion:During EBUS-TBNA for>60 min,PCV combined with VG can not only reduce airway pressure and improve lung compliance,but also prevent respiratory acidosis and improve oxygenation.