Investigations of the Air Volume for a Tracheal Tube Cuff in a Tracheal Models

ABSTRACT

PURPOSE: It is recommended that the cuff is inflated with about 10 ml air because cuff pressure is maintained from 25 cmH2O(=18.39 mmHg) to 40 cmH2O(=29.424 mmHg). This study is performed to evaluate the air volume of highvolume and low-pressure cuff during maintaining appropriate pressure. METHODS: The tracheal models are hexahedral structures were made of monomer Cast Polyamide with a whole diameter from 10 mm to 30 mm at 1mm interval each. They were 1/100 with accuracy. Intubation tube were Hi-LoT M (Mallinckrodt, Athlone, Ireland), high-volume low-pressure cuff tube. The diameter of tubes was from 5.0 mm to 8.0 mm at 0.5 mm interval each. Cuff pressure was measured with cuff pressure control (Tracoe(R), Mains, Germany). Inflated cuff volume is measured by plastic syringe (Becton-Dickson Korea, Seoul, Korea) in maintaining recommended cuff pressure. Volume measurements were twice by each different tester. RESULTS: There were considerable volume differences between each tube size and each model. The bigger trachea model diameter was, the more intracuff air volume was. There was the least volume difference in 5.5 mm intubation tube size (3.5~11.5 ml). There was the most difference in 7.5 mm intubation tube size (3.5~19.5 ml). Totally, the maximum air volume was 22.3 ml, the mininum air volume was 1.5 ml. The difference was 20.8 ml. CONCLUSION: The inflated volumes of cuff in proper cuff pressure were considerably different by the diameter sizes of tracheal models and tube sizes. Therefore, it will be more convenient and safe to use device for maintaining cuff pressure properly.