An in vitro and in vivo validation of a novel monitor for intracuff pressure in cuffed endotracheal tubes

Abstract

The clinical practice of pediatric anesthesiology has changed with increasing use of cuffed endotracheal tubes (cETTs) in infants and children. To limit the risk of tracheal mucosal damage, regular monitoring of intracuff pressure (CP) is necessary. This study evaluates the efficacy and accuracy of a novel syringe device that provides a digital readout of the CP. The study was conducted in two phases. In phase 1, an in vitro study, cETTs of sizes 4.0, 5.0, and 6.0 mm ID were placed into polyvinylchloride tubing of appropriate sizes. The cuffs were then inflated, and the CP was measured simultaneously using the syringe device and a manometer. In phase 2, an in vivo study on 200 pediatric patients, the syringe device and the manometer were simultaneously attached to the pilot balloon to measure the CP following endotracheal intubation. Statistical analysis included linear regression analysis and Bland-Altman comparison. Linear regression analysis of the in vitro study demonstrated an R2 value of 0.9989. Bias and precision were -1.92 ± 0.62 with 95% level of agreement (LOA) ranging from -3.13 to -0.72. For the in vivo study, the linear regression analysis demonstrated an R2 value of 0.9943. The bias and precision were -0.53 ± 0.68 with 95% LOA ranging from -1.86 to 0.81. The study has demonstrated clinically acceptable correlation between the CPs obtained from the standard manometer and the syringe device both in vitro and in vivo. This device is a simple, reliable, portable, and affordable method to monitor CP.