OBJECTIVE:The purpose of the present study was to compare how many inflate and deflate are necessary to maintain the endotracheal tube cuff pressure between 15 and 35 cm H₂O by using air, O₂-N₂O mix or saline solution. STUDY DESIGN:Randomized and prospective study. PATIENTS AND METHODS:Ninety children from 1 month to 15 years of age were included in the study. All patients were ventilated with O₂50%-N₂O50%. Subsequently, the patients were divided in three groups: (1) Group 1: patients with air inflated cuffs; (2) Group 2: patients with O₂-N₂O mix inflated cuffs; (3) Group 3: patients with saline solution inflated cuffs. In all groups cuffs were inflated to reach an intracuff pressure of 20 cm H₂O. The cuff pressure was then monitored every 10 minutes and adjusted to be between 15 and 35 cm H₂O. Laryngeal and tracheal symptoms were noted in the recovery room. RESULTS:The three groups of patients were similar for age, weight, and sex. The length of surgery was significantly longer in Group 3. The deflate rate was higher in Group 1 (60%) than in Group 2 (10%) or 3 (3.3%) (p<0.0001). The inflate rate was higher in Group 2 (76.6%) than in Group 1 or 3 (both 3.3%) (p<0.0001). Side effects were comparable in the three groups of patients. CONCLUSION:Using air or O₂-N₂O mix to inflate cuffs is not reliable. SSI helps to maintain a more stable cuff pressure but monitoring is difficult and sometimes contraindicated by tracheal tubes producers. Inflating cuffs with air and regularly monitoring pressure is the most reliable and easiest technique.