| Objective:To investigate the effect of ventilation mode“pressure-controlled ventilation-volume guaranteed”（PCV-VG）on intraoperative pulmonary ventilation and postoperative pulmonary complications（PPCs）in elderly patients undergoing thoracoscopic surgery.Methods:Sixty patients,aged 65-80 years old,of American Society of Anesthesiologists（ASA）classificationⅡorⅢ,with body mass index（BMI）18-30 kg/m2,scheduled for thoracoscopic lobectomy from November 2021 to June 2022 in the Second Hospital of Shanxi Medical University were recruited.All patients were equally assigned into two groups（n=30 each）in a controlled,randomized design:PCV-VG group（group P）or VCV group（group V）.The ventilatory parameters of two-lung ventilation（TLV）were set at 10-12 breaths/min,with a volume of 8 ml/kg（ideal body weight,IBW）.The ventilatory parameters of one-lung ventilation（OLV）were set at 12-16 breaths/min,with a volume of 6 ml/kg（IBW）.The end-tidal carbon dioxide pressure(PETCO2)was maintained at 35-45 mm Hg and saturation of pulse oxygen（Sp O2）was maintained at above 90%.The incidence and severity of PPCs,chest tube duration,postoperative hospital stay were recorded.Peak airway pressure（Ppeak）,plateau airway pressure（Pplat）,PETCO2 were obtained at three different time points:（1）1 min before OLV（T0）,（2）30 min after OLV（T1）,（3）60 min after OLV（T2）and calculated the dynamic lung compliance（Cdyn）,driving pressure（ΔP）.Heart rate（HR）and mean arterial pressure（MAP）were obtained at T0-T2,and 1 ml of arterial blood was collected at each time point for arterial blood gas analysis in both groups.Results:The incidence of PPCs and chest tube duration in group P were lower compared with group V,but did not show a statistically significant difference（P>0.05）.Compared with group V,the proportion of patients with PPCs grade≥2 was significantly lower in group P[3 patients（10%）vs 11 patients（36%）,Chi-square test,=5.963,P<0.05].The length of hospital stay after surgery was significantly shorter in group P than in group V[（6.43±1.25）d vs（8.03±1.90）d,Student’s t-test,t=3.849,P<0.001].Ppeak,Pplat andΔP were significantly higher（P<0.001）and Cdyn was significantly lower（P<0.001）in both groups at T1-T2 than at T0.Ppeak,Pplat andΔP were decreased（P<0.05）and Cdyn was significantly increased（P<0.05）in group P compared with group V.No significant differences were found in HR,MAP,PETCO2,Pa O2,Pa CO2 between the two groups.Conclusion:In conclusion,PCV-VG mode can improve intraoperative ventilation by reducing airway pressure,ΔP and enhancing Cdyn,and effectively decrease the severity of PPCs in elderly patients undergoing thoracoscopic surgery,shorten the length of postoperative hospital stay,and facilitate early postoperative recovery of patients. |
