[A clinical study on the determination of cuff pressure in artificial airway by minimum air leakage method].

Objective: To compare the cuff pressure and leakage volume and the related complications of filling the tracheal tube cuff by minimum air leakage method and cuff pressure manometer method after endotracheal intubation, so as to provide theoretical basis for patients who was intubated to obtain appropriate cuff pressure.

Methods: A prospective randomized controlled study was conducted. 100 patients admitted to the department of critical care medicine of the Fifth Center Hospital in Tianjin from December 2015 to June 2019 were enrolled. According to the random number table method, the patients were divided into the experimental group and control group, with 50 patients in each group. After successful endotracheal intubation, all patients were placed in a supine position with the head of the bed raised by 30 degree angle. The experimental group used the minimum air leakage method, and used the cuff pressure manometer to obtain the cuff pressure. In the control group, cuff pressure was maintained at 25-30 cmHO (1 cmHO = 0.098 kPa). Parameters such as cuff pressure and ventilator leakage volume at the beginning and 4 hours, 8 hours after the inflation were compared between the two groups, as well as the incidence of ventilation-associated pneumonia (VAP) and airway complications after extubation.

Results: Among the 100 cases, 53 were males and 47 were females. The age ranged from 23 to 87 years old, with an average of (68.53±8.46) years old. The intubation time ranged from 1 to 16 days. (1) At 4 hours and 8 hours after inflation, the cuff pressures of the two groups were lower than that of the first time of inflation, and the air leakage of the ventilator increased gradually with the extension of time. Compared with the control group, cuff pressures at each time point in the experimental group were significantly higher than those in the control group [mmHg (1 mmHg = 0.133 kPa): 33.72±9.14 vs. 25.68±5.26 at 0 hour, 30.54±7.81 vs. 24.35±4.93 at 4 hours, 26.57±5.64 vs. 22.42±4.14 at 8 hours, all P < 0.05], and ventilator leakage volumes were smaller than those in the control group (mL: 25.57±8.51 vs. 34.65±9.47 at 0 hour, 40.54±8.51 vs. 60.34±7.85 at 4 hours, both P < 0.05). (2) The incidence of VAP in the experimental group was significantly lower than that in the control group (4% vs. 10%, P < 0.05). There was no statistically significant difference in the incidence of other airway complications between the experimental group and control group (airway mucosal edema: 14% vs. 12%, ulcer: 8% vs. 6%, tracheal esophageal fistula: 0% vs. 0%, hoarseness: 4% vs. 6%, cough: 30% vs. 34%, sore throat: 28% vs. 32%, tracheal softening: 0% vs. 0%, cuff rupture: 10% vs. 8%, all P > 0.05).

Conclusions: The optimal cuff pressure is very important for preventing VAP and reducing airway complications. The minimum air leakage method makes the clinical obtained endotracheal intubation cuff pressure more accurately, with less air leakage, safe and effective, and it is worthy of clinical promotion.