[Determination of air volume in the entotracheals tube cuff]

The aim of this study is to determine the best regulation of air volume to be inflated into cuffs of different endotracheal canula diameters of high residual volume and low pressure. Maintaining the pressure exercised by a balloon in the trachea mucous membrane between preconized limits of 20 to 30 mmHg (less than the trachea capillary pressure). Therefore, 10 ml of air have been inflated into the canular cuff of intubed patients with different internal diameters (7.0-7.5- 8.0-8.5-9.0) one by one, measuring each millilitre of inflated air, the corresponding to pressure of the cuff in the trachea mucous membrane. The monitoring of the pressure has been made by a previously calibrated manometer. The procedure has been performed in 25 adult patients of both sexes, grouped in numbers of 5 for each internal tube diameter. The results have been analysed through linear regression analysis which has shown a close relationship between ml of inflated air and pressure in the cuff by tube diameter. After analysing the results, the author indicated, by means of graphic representation, the quantity of air to be inflated in the cuff and respective exercised pressure on the trachea mucous membrane, by tube meter, in a way to offer a contribution to the staff who provides assistance to intubed patients, in the sense of minimising the possible injuries and complications and assure a better respiratory ventilation.