正压通气下呼吸道气阻与顺应性在线测算方法改进

:目的 采用气道正压对患者进行通气治疗,实现对通气患者呼吸道气阻(resistance, R)和顺应性(compliance, C)在线测算。 方法 当呼气末气流为 0 时,在呼气支持压(expiratory positive airway pressure, EPAP)之上叠加 1 个负 脉冲气压,使肺内气压在该脉冲期间高于体外气压,从而向外泄放气流,并对该泄放气流进行处理来测算 R 和 C。 然 后以正常成人、典型急性呼吸窘迫综合征( acute respiratory distress syndrome, ARDS) 患者和慢性阻塞性肺疾病 (chronic obstructive pulmonary disease, COPD)患者为实验对象,建立仿真实验平台,进行仿真实验来测算 R 和 C。 结 果 所测算的正常成人 R 和 C 误差分别为 3. 398% 和-3. 288% ,COPD 患者 R 和 C 误差分别为 1. 265% 和-1. 348% , ARDS 患者 R 和 C 误差分别为 3. 400% 和-3. 286% 。 结论 气道正压通气下,采用呼气末叠加 1 个负脉冲气压在 EPAP 上来测算 R 和 C 的方法具有良好的可行性,研究结果为智能调控通气、精准通气等技术打下坚实基础。

Improvement of Online Monitoring of Airway Resistance and Compliance under Positive Pressure Ventilation

Objective To realize the online estimation of airway resistance ( R) by applying positive airway pressure in ventilation treatment. Methods At the end of expiration when the airflow was zero, with a negative pulse pressure superposed upon the expiratory positive airway pressure (EPAP), a discharged airflow in the airway was produced, and the R and C were calculated with the discharged airflow. Then, taking the simulated normal adult, typical patients with acute respiratory distress syndrome (ARDS) and patient with chronic obstructive pulmonary disease (COPD) as experimental subjects, a simulated platform was established and the simulation experiments were conducted to calculate R and C. Results The errors in R and C were 3. 398% and -3. 288% for the simulated normal adult, 1. 265% and -1. 348% for the simulated patient with COPD, 3. 400% and -3. 286% for the simulated patient with ARDS, respectively. Conclusions The method with a negative pulse pressure superposed upon the EPAP to conduct the R and C is well practicable. This study lays solid foundation for the technology of intelligent and precision ventilation.