Lung-protective effect of lung-protective ventilation combined with pressure-controlled ventilation-volume guaranteed in elderly patients undergoing one-lung ventilation

Abstract

Objective To evaluate the lung-protective effect of lung-protective ventilation(LPV)combined with ventilatory mode pressure-controlled ventilation-volume guaranteed(PCV-VG)in elderly patients undergoing one-lung ventilation(OLV). Methods Eighty American Society of Anesthesiologists physical statusⅠ-Ⅲ patients, aged 65-80 yr, with body mass index of 15-28 kg/m2, scheduled for elective radical resection for esophageal cancer performed via video-assisted thoracoscope, were divided into 4 groups(n=20 each)using a random number table: control group(group C), PCV-VG group, LPV group and LPV combined with PCV-VG group(group LPV+ PCV-VG). At 20 min after changing the body position during two-lung ventilation(T1), 30 min of OLV(T2)and 20 min after restoration of two-lung ventilation(T3), blood samples were collected from the radial artery for blood gas analysis and for determination of peak airway pressure(Ppeak), mean airway pressure(Pmean)and dynamic lung compliance(Cdyn). Alveolar-arterial oxygen gradient, intrapulmonary shunt(Qs/Qt), dead space fraction(Vd/VT)and respiratory index were calculated at T2.Blood samples were collected from the radial artery before induction of anesthesia and at the end of operation for determination of plasma neutrophil elastase(NE)concentrations by enzyme-linked immunosorbent assay.The Clinical Pulmonary Infection Score(CPIS)was assessed at 1 and 7 days after operation, and the development of pulmonary complications such as respiratory failure, pulmonary atelectasis and pulmonary infection was recorded within 7 days after operation. Results Compared with group C, Ppeak was significantly decreased, and Pmean was increased in group PCV-VG, Ppeak and PaCO2 were significantly increased and pH value, Vd/VT and Qs/Qt were decreased in group LPV, Ppeak, Vd/VT, Qs/Qt, pH value and postoperative CPIS were significantly decreased, and Pmean, Cdyn and PaO2 were increased in group LPV+ PCV-VG, and the NE concentration at the end of operation was significantly decreased in PCV-VG, LPV and LPV+ PCV-VG groups(P<0.05). Compared with group PCV-VG, Pmean, Cdyn and PaO2 were significantly increased, and pH value, Qs/Qt, NE concentration at the end of operation and CPIS were decreased in group LPV+ PCV-VG(P<0.05). Compared with group LPV, Ppeak, Qs/Qt, NE concentration at the end of operation and CPIS were significantly decreased, and Cdyn was increased in group LPV+ PCV-VG(P<0.05). Pulmonary complications such as respiratory failure, pulmonary atelectasis and pulmonary infection were not observed after operation in the four groups. Conclusion LPV combined with PCV-VG can optimize the lung-protective effect in elderly patients undergoing OLV. Key words: Respiration, artificial; Aged