Effect of high-frequency oscillatory ventilation on lung injury in piglets with acute respiratory distress syndrome / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of high-frequency oscillatory ventilation (HFOV) on lung injury in the piglets with acute respiratory distress syndrome (ARDS).Methods Twelve male piglets,aged 6-8 weeks,weighing 14-16 kg,were randomly divided into 2 groups (n=6 each) using a random number tableconventional mechanical ventilation with low tidal volume group (CMV group) and HFOV group.ARDS was induced by bilateral pulmonary lavages with isotonic saline (38 ℃),repeated every 10 min until the oxygenation index＜200 mmHg.After successful establishment of the model,CMV group was ventilated using conventional mechanical ventilation with low tidal volumes.After successful establishment of the model,HFOV group was ventilated using HFOV,lung recruitment was performed,the airway pressure was set at 25 cmH2O and maintained at this level for 30 s,and the airway pressure was then adjusted 5 cmH2O higher than that after successful establishment of the model,with bias flow 25 L/min,inspiratory time ratio 33％,frequency 8 Hz,amplitude 40-80 cmH2O,and inspiratory oxygen fraction 1.0.In both groups,carbon dioxide partial pressure was maintained between 35 and 50 mmHg.Before establishment of the model (baseline),after successful establishment of the model (T1),and at 0.5,1.0,2.0 and 4.0 h after beginning of mechanical ventilation (T2-5),blood samples were collected from the femoral artery and central vein for blood gas analysis,arterial oxygen partial pressure and carbon dioxide partial pressure were recorded,oxygen delivery index,oxygen consumption index,oxygenation index and intrapulmonary shunt were calculated,and the improvement in pulmonary function (oxygenation index ≥ 200 mmHg) was recorded.At T0,T1 and T5,venous blood samples were collected for determination of the concentrations of serum Clara cell secretory protein 16,soluble intercellular adhesion molecule-1,and high-mobility group box 1.Results Compared with CMV group,the arterial oxygen partial pressure at T35 and oxygenation index at T4.5 were significantly increased (P ＜ 0.05),and no significant change was found in the other parameters in HFOV group (P＞0.05).Conclusion Compared with conventional mechanical ventilation with low tidal volumes,although HFOV improves lung oxygenation,the degree is small in the piglets with ARDS.