Effects of lubrication on air-sealing performance of a pediatric cuffed tracheal tube

BACKGROUND: Lubrication of cuffed tracheal tubes (CTTs) reduces liquid leakage. However, it is not clear how cuff lubrication influences air leakage. We aimed to test the hypothesis that pretreatment with K-Y jelly, a water-soluble lubricant, would improve the air-sealing performance of pediatric CTTs in a model study. METHODS: We placed Parker Flex-Tip™ CTT with 4.0- and 5.0-mm internal diameter (ID) into a tracheal model with 9- and 12-mm ID. The tracheal model was connected to a test lung ventilated in pressure control mode. We compared three cuff lubrication conditions: none (N), water (W), and K-Y jelly (KY). We measured the leak airway pressure (LAWP), defined as the lowest peak airway pressure (PAWP) at which leakage was detected, with the fixed cuff pressure (CP) at 20 cmH(2)O and varied PAWP. We also measured the leak CP (LCP), defined as the highest CP at which leakage was detected, with fixed PAWP at 25 cmH(2)O and varied CP. We confirmed air leakage when an apparent elevation of oxygen concentration was detected above the cuff after changing the inspiratory gas from air to oxygen. RESULTS: For both 4.0-mm ID and 5.0-mm ID endotracheal tubes, the KY group showed significantly higher LAWP and lower LCP than the other two groups. For the 4.0-mm ID, median values and ranges of LAWP and LCP were K-Y group: 25 (25) and 15 (15); N group: 5 (5) and 35 (35): and W group: 5 (5) and 35 (15–35) cmH(2)O. For the 5.0-mm ID, median values and ranges of LAWP and LCP were K-Y group: 25 (15–25) and 15 (15–35); N group: 5 (5) and 35 (35); and W group: 5 (5) and 35 (15–35) cmH(2)O. Water application did not change these outcomes compared with the N group. CONCLUSION: Pre-treatment of the cuff with K-Y jelly significantly improved the air-sealing performance of a pediatric CTT in our model study.