Cuffed endotracheal tubes in infants and children: a technique to continuously measure the intracuff pressure

Abstract

Objectives: Various devices have been used to measure the intracuff pressure (CP) of an endotracheal tube at the time of inflation; however, no device has found widespread acceptance for the continuous monitoring of CP. We devised a simple method to continuously measure the CP using an invasive pressure monitoring setup (IPMS), which is used routinely in the operating room to monitor arterial or central venous pressures. The accuracy of the device was compared to those obtained from a commercially available and clinically used manometer (MM).

Methods: Size 4.0, 5.0 and 6.0 mm ID cETTs were placed into one of 3 sizes of polyvinylchloride (PVC) tubes. The cuff of the cETT was inflated after inserting the cETT into the PVC pipes. After inflation, the CP was simultaneously checked using the MM and the IPMS. A total of 100 simultaneous (IPMS and MM) readings were obtained from each of the 3 sizes of cETT with the intracuff pressure randomly varying between 10 and 40 cmH₂O. Statistical analysis included a Bland-Altman comparison to determine the bias, mean, and 95% levels of agreement (LOA), and a linear regression analysis.

Results: Linear regression analysis demonstrated an R(2) value of 0.988, 0.9899, and 0.9879 when comparing the pressure from the IPMS and MM from the 4.0, 5.0 and 6.0 mm cETT, respectively.

Conclusions: A standard IPMS can be used to continuously monitor intracuff pressure with the use of a cETT. Although various techniques can be used safely to avoid hyperinflation of the cuff, they provide only an instantaneous measure of the CP. The current technique allows for continuous monitoring of CP during prolonged cases or in other clinical scenarios when such monitoring is required.