Value of lung ultrasound examination in making decision of severe acute respiratory distress syndrome receiving prone ventilation

Objective To investigate the ideal persistence time of prone position ventilation in patients with severe acute respiratory distress syndrome(ARDS). Methods Collect 78 cases of severe ARDS admitted to the ICU unit of Sichuan Provincial People's Hospital from October 2012 to June 2014, all the ARDS patients needed to receive 8 h/day prone position continuous 5 day. For each of the prone position ventilation, ultrasound patterns were recorded and the aeration scores were calculated at the beginning of the prone position(T0)and 2 h(T1), 4 h(T2), 6 h(T3), 8 h(T4) later. The correlation of the aeration score variation (ASV) and the arterial blood gas indexes (pH, PaO2, PaCO2, PaO2 /FiO2) were recorded also.The adverse reactions, ventilator situation and oxygen fraction after 7 days, 28-day mortality were monitored. Results The aeration score of the lung at T1, T2, T3, T4 was significantly reduced than T0 all, the ventilation situation of mainly areas was improved after 2 h PPV (P 0.05); the value of PaO2, PaO2 /FiO2 was greater at T1, T2, T3, T4 than T0(P 300 mmHg after 5 days PPV was 65(83.3%); there were 30(38.5%)patients free of mechanical ventilation after 7 days; the 28-day mortality was 7(8.97%). Conclusion In patients with severe ARDS, applicating 2-4 hours validity of prone position ventilation significantly improves the pulmonary ventilation, more than 4 h PPV do not better for patients probably. Key words: Respiratory distress syndrome, adult; Uhrasonography; Prone position; Mechanical ventilation