DETERMINARON OF THE AIR VOLUME IN THE "CUFF" OF THE ENDOTRACHEAL TUBE

Abstract

The objective of this study was to determine the best regulation of the air volume to be inflated into the cuff of different endotrachea canula diameters of hight residual volume and law pressure; maintaining the pressure exercised by balloon in the mucous membrane of the trachea between of the preconized limits of 20 to 30 mmHg (less than the trachea capillary pressure). Therefore 10 mi of air was inflated into the canular cuff of intubed patients with internal diameters (7.0 - 7.5 - 8.0 - 8.5 - 9.0) one by one, measuring each mi of inflated air, the corresponding pressure of the cuff in the trachea mucous membrane. The monitoring of the pressure was done by a previously calibrated manometer. The procedure was performed in 25 adult patients of both sexes, grouped in numbers of 5 for each internal tube diameter. The results were analyzed through linear regression analysis which showed the approximate relationship between mi of inflated air and pressure in the cuff by tube diameter. After analyzing the results, the authors constructed a graph with the indication of the quantity of air to be inflated in the cuff and respective exercised pressure on the trachea mucous membrane, by tube diameter, in a way to offer a contribuition to the staff that gives assistance to intubed patients, in the sense of minimizing the possible injuries and complications and assure a better respiratory ventilation.