Difference of Short Term Survival in Patients with ARDS According to Responsiveness to Alveolar Recruitment / 결핵

ABSTRACT

BACKGROUND: Lung protective strategies, using low tidal volume in ARDS, improve survival rate in ARDS. However, low tidal volume ventilation may promote alveolar de-recruitment. Therefore, alveolar recruitment is necessary to maintain arterial oxygenation and to prevent repetitive opening and closure of collapsed alveoli in lung protective strategies. There has been a recent report describing improvement in arterial oxygenation with use of recruitment maneuver. However, impact of recruitment on outcome of ARDS is unknown. We evaluated whether short-term survival difference existed in patients with ARDS, who were performed alveolar recruitment maneuver(ARM) and prone position, according to response of alveolar recruitment or not. METHODS: All patients who were diagnosed with ADRS and received mechanical ventilation were included. ARM were sustained inflation(35-45 cmH2O CPAP for 30-40 sec.) or increasing level of PEEP. If these methods were ineffective, alveolar recruitment with prone position was done for at least 10 hours. PaO2/FiO2(P/F) ratio was determined before and at 0.5 and 2 hours after ARM. We defined a responder if the P/F ratio was increased over 50% of baseline value. We compared 10-days and 30-days survival rate between responders and non-responders. RESULTS: 20 patients(M:F=12:8, 63 +/- 14 age) were included. Among them, 12 patients were responders and 8 patients were non-responders. In responders, P/F ratio was increased from 92 +/- 25 mmHg to 244 +/- 85 mmHg. In non-responders, P/F ratio increased from 138 +/- 37 mmHg to 163 +/- 60 mmHg. Among non-responders, P/F ratio was improved over 50% in 2 patients after prone position. Overall, 14 patients were responders after ARM and prone position. The 10-days and 30-days survival rate in responders was significantly higher than in non-responders(86%, 57% in responders and 33%, 0% in non-responders)(p<0.05). There was no significant difference between responders and non-responders in age(71 +/- 11, 60 +/- 14), lung injury score(2.8 +/- 0.2, 2.9 +/- 0.45), simplified acute physiology score(SAPS) II (35 +/- 4.6, 34 +/- 5.7), positive end-positive pressure level(15.6 +/- 1.9 cmH2O, 14.5 +/- 2.1 cmH2O). CONCLUSION: ARM may improve arterial oxygenation in some patients with ARDS. These responders in patients with ARDS showed significant higher 10-days and 30-days survival rate than non-responders patients with alveolar recruitment.