Application of different ventilation modes combined with Autoflow technique in thoracic surgery and its influence on respiratory mechanics

ObjectiveTo investigate the effects of different ventilation modes + Autoflow technique on respiratory mechanical indexes of patients undergoing thoracic surgery.

MethodsA total of 96 patients with lung cancer treated by thoracic surgery from December 2018 to June 2020 were randomly divided into 6 groups, with 16 cases in each group.Group A: volume-controlled ventilation(VCV) tidal volume(Vt) 5 mL/kg+PEEP 4 mmHg+Autoflow mode; group B: VCV(Vt 5 mL/kg) + PEEP 4 mmHg+Constflow mode; group C: VCV(Vt 5 mL/kg)+PEEP 8 mmHg+Autoflow mode; group D: VCV(Vt 5 mL/kg) +PEEP 8 mmHg+Constflow mode; group E: VCV(Vt 8 mL/kg) +Autoflow mode; group F: VCV(Vt 8 mL/kg)+Constflow mode.The changes of peak inspiratory pressure(APIP), airway resistance(Raw), chest compliance(C), heart rate(HR), mean arterial pressure(MAP) and arterial partial oxygen pressure(PaO₂) were compared in each group at bilateral lung ventilation, ventilation for 1 hour and for 2 hours.

ResultsThere were no statistically significant differences in the levels of APIP, Raw, C, HR, MAP and PaO₂ in each group during bilateral lung ventilation(P>0.05).After 1 hour of ventilation, APIP and Raw in group B, E and F were higher than those in group A and C(P < 0.05), the C value in group C was lower than that in other groups(P < 0.05), the PaO₂ in group C was lower than that in group B(P < 0.05), there was no significant difference among other groups(P>0.05).After 2 hours of ventilation, APIP and Raw in group B, E and F were higher than those in group A and C(P < 0.05), the C value in group B was lower than that in group A(P < 0.05), the PaO₂ value of group A and group B was lower than that in group C(P < 0.05), there was no significant difference among other groups(P>0.05).After ventilation for 1 hour and 2 hours, there was no significant difference in HR and MAP among the groups(P>0.05).

ConclusionsVCV(Vt 5 mL / kg) + PEEP 8 mmHg + Autoflow mode can reduce airway peak pressure and resistance, improve arterial oxygen partial pressure, and effectively prevent injury caused by mechanical ventilation in elderly patients treated by thoracic surgery.