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 cmH2O. 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. Key words: Artificial airway; Airbag pressure; Mathematical model of airbag pressure decay