Effect of postural changes on the mechanical ventilation in patients with acute respiratory distress syndrome

Abstract

Objective To compare the effect of postural changes on the mechanical ventilation in patients with acute respiratory distress syndrome （ ARDS ） .Methods A total of 40 ARDS patients with mechanical ventilation from January 2010 to December 2012 and without contraindications for mechanical ventilation in the prone position were selected , who were divided into the prone position ventilation group and the supine position ventilation group by random number table method , with 20 patients in each group .The changes of vital signs and arterial blood gas before and after mechanical ventilation were compared between the two groups, including the mean airway pressure , plateau pressure and airway resistance three days after treatment . Also, the mechanical ventilation time and the time taken to stay emergency room were compared between the two groups.Results Compared with before treatment , the T, P, MAP and PaCO2 after treatment all decreased in the two groups, with statistically significant differences （P＜0.01）;the PETCO2, pH, PaO2, PaO2/FiO2 after treatment all increased in the two groups , with statistically significant differences （P＜0.01）.There were no statistically significant differences between the two groups in T , P, PETCO2 , MAP, pH, PaO2 , PaCO2 （ P＞0.05）.The PaO2/FiO2 in the prone position ventilation group was （282 ±177;22） three days after treatment , which was higher than that of （245 ±177;21） in the supine position ventilation group three days after treatment , and the difference was statistically significant （t=6.18, P＜0.01）.The mean airway pressure, plateau pressure and airway resistance three days after treatment was （6.8 ±177;0.5） cmH2O, （17.1 ±177;2.0） cmH2O and （14.9 ±177; 1.2）cmH2O/（L±183; s） in the prone position ventilation group, respectively, which was （8.5 ±177;0.9） cmH2O, （20.6 ±177;2.3）cmH2O and （21.1 ±177;0.8）cmH2O/（L±183; s） in the supine position ventilation group , respectively, and the differences were statistically significant （t =7.38, 5.13, 18.83, respectively;P ＜0.01）.The mechanical ventilation time and the time taken to stay emergency room in the prone position ventilation group were shorter than those in the supine position ventilation , and the differences were statistically significant （ t=9.007, 6.379, respectively;P ＜0.01）.Conclusions Prone position ventilation can be more effective in improving oxygenation index and redressing hypoxemia , and has relatively little impact on the patients ’ airway, which is an ideal position of mechanical ventilation . Key words: Respiratory distress syndrome,adult; Position; Mechanical ventilation