人工气道气囊压力衰减数学模型的建立及应用

目的：连续监测机械通气患者的人工气道气囊压力，建立其压力衰减的数学模型，探讨气囊压力的最佳监测频率。方法选取呼吸重症监护室辅助通气患者158例，根据指南推荐的人工气道气囊压力最高限，调整压力到30 cmH2 O，采用PORTEX压力监测表，每小时监测并记录实际压力，基于测得的压力数据，使用曲线拟合法建立压力衰减数学模型，计算获得人工气道气囊压力监测的合适频率。结果取每小时测取的气囊压力平均值做曲线拟合，建立数学模型，计算得出最佳间隔时间为4．24 h；取每小时测取的气囊压力的下限做曲线拟合，则得出最佳间隔时间为3．06 h。结论建立人工气道呼吸机辅助呼吸的患者，至少间隔4．24 h监测并校正气囊压力一次；若基于更为安全的角度考虑，以防止气囊漏气及相应并发症的发生，应间隔3．06 h监测并校正气囊压力一次。

Mathematical model building of airbag pressure decay used in artificial airway patients

Objective To monitor the airbag pressure of artificial airway in mechanical ventilation patients, and to establish a mathematical model of airbag pressure decay, so as to explore the best interval of time for airbag pressure monitoring and provide a scientific basis to standardize the management of those patients.Methods Totals of 158 patients in respiratory intensive care unit （ RICU） with artificial airway were selected according to the upper limit of value, recommended by the guideline, the pressure of airbag was revised to 30 cmH2 O.The PORTEX pressure monitoring table was used and recorded every hour.Based on the recorded value, the mathematical model of airbag pressure decay was established using the curve fitting method, and then obtained the suitable interval of time for airbag pressure monitoring.Results Based on the recorded value and establishment of the mathematical model of airbag pressure decay, the optimum interval of time was 4.24 hours. If based on the lower limit of airbag pressure checked each hour, the optimum interval of time was 3.06 hours. Conclusions For the patients who have set up an artificial airway, the time for monitoring and correcting airbag pressure should be at least 4.24 hours.If based on a more safety point of view to prevent air leakage and the occurrence of complications, it should be at least 3.06 hours.