Application of Perifix(R) LOR (Loss of Resistance) Syringe for Obtaining Adequate Intracuff Pressures of Endotracheal Tubes

Cho, Choon Kyu; Kwon, Hee Uk; Lee, Mi Jin; Park, Seong Soo; Jeong, Won Joon

Abstract

PURPOSE
The management of cuffed endotracheal (ET) tubes is routine practice for emergency physicians. Although various cuff inflation techniques are used, there is no standard technique identified in the literature as the method for cuff inflation or intracuffed pressure (ICP). A loss of resistance (LOR) syringe has been used for years and this is located in the epidural space. The purpose of this study was to measure the actual ICP obtained by a new estimation technique.
METHODS
Using a manikin simulation model, we assessed how physicians inflated the cuff in 5.5, 6.5, 7.5 mm inner diameter ET tubes. We measured the inflated air volumes and the ICPs obtained by the conventional technique (A group), by the commercial 10-ml syringe + passive release technique (B group), and by a LOR syringe + PRT (C group). Subsequently, a manometer was used to measure the actual ICP (normal: 16 to 40 cmH2O).
RESULTS
We sampled 90 participants. They were classified into three groups: those who underwent the conventional inflation technique (A group, n=30), those who underwent the commercial syringe technique (B group, n=30) and those who underwent the Perifix(R) LOR syringe technique (C group, n=30). In the control group, the mean recorded ICPs were 78.2+/-30.7 cmH2O (A group) and 56.1+/-16.0 cmH2O (B group). The initial cuff pressures were greater than 40 cmH2O in 25 (83.3%) cases. For the experimental group, the mean recorded ICP was 19.1+/-1.8 cmH2O. With respect to the rate of optimal cuff inflation, the LOR syringe technique was significantly higher than the conventional method or the PRT + 10-ml syringe method (100% vs. 16.7 and 23.3%, respectively, p<0.001).
CONCLUSION
Using conventional syringe technique, most cuff pressures exceeded a safe pressure and they required correction. Ultimately, PRT using the Perifix(R) LOR syringe is a useful alternative cuff inflation method when direct intracuff pressure measurement is not available.