A Meta-analysis And Clinical Observation Of The Effect High-frequency Oscillatory Ventilation For Adult Patients With ARDS

Objective:In order to systematically evaluate the safety and efficacy of high-frequency oscillatory ventilation(HFOV) for adult patients with acute respiratory distress syndrome(ARDS) vs.conventional mechanical ventilation(CMV).Methods:Part 1:Summarize the published articles concerning randomized controlled trials(RCTs) on the application of HFOV vs.CMV for adult patients with ARDS.Articles published before May 2016 were included according to the established inclusion and exclusion criteria.Statistical analysis was performed by Review Manager 5.3 software.The evaluation indicators include 28/30-days mortality,indication rate of complications,the duration of mechanical ventilation,PaO2/FiO2,mean airway pressure,hemodynamic parameters.Part 2:Nine adult patients with ARDS undergoing HFOV treatment.We used the SensorMedics 3100 B high-frequency oscillatory ventilator.Oxygenation index(PaO2,PaCO2,PaO2/FiO2,arterial PH,OI(mPaw×FiO2×100/PaO2)),hemodynamic parameters(mean arterial pressure(MAP), heart rate(HR), central venous pressure(CVP)),complications(hemodynamic disorders,ventilator-associated lung injury,mucus-plugged ET tube)were recorded and the use of narcotic neuromuscular blockers and vasoactive drugs were also recorded.Results:Part 1:Nine randomized controlled trials with 1779 patients were included.There were897 patients in the HFOV group and 882 patients in the CMV group.Meta-analysis by RevMan 5.3.Compared with CMV,HFOV is associated with significant improvement in PaO2/FiO2(P<0.01),reducing the incidence of refractory hypoxemia(P=0.02<0.05).Therisk factors of adverse events including pneumothorax,refractory hypotension,acidosis were similar(P=0.76).But compared with CMV,HFOV did not show any statistically significant beneficial effects on mortality(P=0.67).And HFOV tend to prolong the duration of ventilation vs. CMV(P=0.04<0.05).Part 2:PaO2 was improved in nine patients after 30 minutes after HFOV treatment(P<0.01).PaO2/FiO2 was significantly higher than baseline(P<0.01).OI was significantly decreased(P<0.01).PaO2 ? PaO2/FiO2 ? OI had no significance difference between 60 minutes and 30 minutes.PaCO2 increased gradually after HFOV treatment.PaCO2 at 30 minutes was significantly higher than baseline(P<0.01),and continued to increase after 60 minutes(P<0.05).Arterial PH decreased in progressive after 30 minutes(P<0.01)and 60 minutes(P<0.05).There were no obvious change of HR and MAP.CVP was increased right after HFOV started and remained stable after 5 minutes. Within nine patients, circulatory system complications occurred in two patients. Both of them showed the arrhythmia.No respiratory complications such as subcutaneous emphysema,pneumothorax has been found.We used propofol(2.47±0.55mg/kg), midazolam(0.14±0.05mg/kg) as sedative.Vecuronium bromide(0.11±0.03mg/kg) was used as neuromuscular blocker.The effect of these drugs were satisfactory.Conclusions: HFOV provides better effect than CMV in improve oxygenation and the strategy is proved to be safe and effective.