BACKGROUND: Acute and chronic hyperinflation of tracheal tube cuffs represents a persistent risk factor for airway damage in children when cuffed tracheal tubes are used. In order to overcome this particular risk, a cuff pressure (CP) pop-off valve has been designed to avoid CP exceeding 20 cmH(2)O. METHODS: The performance of the novel pop-off valve has been evaluated in an in vitro set-up during slow and rapid air insufflation by a syringe or a CP manometer or inadvertent compression of the cuff pilot balloon while measuring cuff and tracheal wall pressure (WP) in ID 3.0 mm cuffed tracheal tubes. Steady-state performance was evaluated during nitrous oxide exposure of tracheal tube cuffs (ID 3.0 mm). RESULTS: The novel CP pop-off valve avoided cuff hyperinflation during rapid air volume changes and showed reliable performance during steady-state nitrous oxide exposure to the tube cuff. CONCLUSIONS: These preliminary results show that the CP pop-off valve limits the effect of rapid, potentially dangerous manual cuff inflation maneuvers and reliably prevents CP exceeding the predetermined level of 20 cmH(2)O when exposed to nitrous oxide.
BACKGROUND: Acute and chronic hyperinflation of tracheal tube cuffs represents a persistent risk factor for airway damage in children when cuffed tracheal tubes are used. In order to overcome this particular risk, a cuff pressure (CP) pop-off valve has been designed to avoid CP exceeding 20 cmH(2)O. METHODS: The performance of the novel pop-off valve has been evaluated in an in vitro set-up during slow and rapid air insufflation by a syringe or a CP manometer or inadvertent compression of the cuff pilot balloon while measuring cuff and tracheal wall pressure (WP) in ID 3.0 mm cuffed tracheal tubes. Steady-state performance was evaluated during nitrous oxide exposure of tracheal tube cuffs (ID 3.0 mm). RESULTS: The novel CP pop-off valve avoided cuff hyperinflation during rapid air volume changes and showed reliable performance during steady-state nitrous oxide exposure to the tube cuff. CONCLUSIONS: These preliminary results show that the CP pop-off valve limits the effect of rapid, potentially dangerous manual cuff inflation maneuvers and reliably prevents CP exceeding the predetermined level of 20 cmH(2)O when exposed to nitrous oxide.