Abstract:

Objective To compare the effects of recruitment maneuver in intra-and extra-pulmonary acute respiratory distress syndromes.Methods Fifty-three patients with ARDS who received recruitment maneuver(RM) were assigned into group ADRSp(n=25) and group ARDSexp(n=28) according to the causes of lung injury. All the patients were ventilated with tidal volume of 6 mL/kg of predicted body weight and limited plateau pressure less than 30 cmH₂O. RMs were conducted by applying CPAP of 40 cmH₂O for 40 s, repeated every 8 hours during the first 5 days. If the patient began weaning within the first 5 days, RMs were stopped . Both physiologic data and outcome measurements, including arterial blood gas(PaO₂, PaCO₂), airway pressure(peak pressure, plateau pressure), ventilator settings( tidal volume, PEEP, FiO₂) , hemodynamic parameters, ICU-free days by day 28, ventilator-free days by day 28 and rate of survival with unassisted breathing by day 28, ICU and 28-day mortality, were compared between 2 groups.Results The PaO₂/FiO₂ increased after RM on day 1 and day 2(144.9 mmHg vs 128.0 mmHg, P=0.007, 205.0 mmHg vs 175.0 mmHg, P=0.001, respectively), accomparied by significant decrease in FiO₂(0.58±0.16 vs 0.68±0.22, P=0.001;0.53±0.15 vs 0.54±0.15, P=0.017; respectively). But there was no significant difference in changes of PaO₂/FiO₂ and FiO₂ between two groups, so was also PaCO₂.During the first 5 days, no differences in peak pressure and plateau pressure between 2 groups were found. Each time when RM was conducted, no difference in heart rate and mean blood pressure before RM and 0.5, 1, 2, 4, 6-hours after RM were found. There were also no differences in ICU-free days, ventilator-free days, rate of survival with unassisted breathing, ICU and 28-day mortality between 2 groups. Only one patient was reported to suffer from low blood pressure when RM was performed. There were no incidence of barotraumas and other adverse effects.Conclusion RM is safe and effective in improving oxygenation in early ARDS. It has a beneficial impacts on the outcome. No significant differences are found in oxygenation, lung mechanics, hemodynamic parameters and prognosis between ARDSexp and ARDSp.

Key words: acute lung injury, acute respiratory distress syndrome, recruitment maneuver, outcome