Differences in lung function after the use of 2 extrication systems: a randomized crossover trial.

OBJECTIVES: The main purpose of this study in healthy volunteers was to compare the lung function effects of 2 extrication devices that use spinal vests: the Kendrick Extrication Device (KED) and the Ferno KED-XT board.

MATERIAL AND METHODS: Randomized crossover trial in 50 healthy adult volunteers. The subjects were placed in the KED and KED-XT devices for 5 minutes each and rested for 10 minutes between devices. Assignment to the first device was randomized. Each subject underwent spirometry at baseline and after placement of each device. The subjects were seated for all tests. The main outcome measures were the mean absolute differences between baseline and other measurements of forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and the FVC/FEV1 ratio.

RESULTS: Use of the devices led to statistically significant mean decreases from baseline FVC (KED-XT, -0.48 L; 95% CI, -0.16 to -0.81 L [P=.016] and KED, -0.79 L; 95% CI, -0.44 to -1.13 L [P<.001]) and from baseline FEV1 (KED-XT, -0.35 L/s; 95% CI, -0.14 to -0.56 L/s [P=.002] and KED, -0.52 L/s; 95% CI, -0.31 to -0.72 L/s [P<.001]). The decrease in FVC was greater after use of the KED device (mean difference, KED vs KED-XT, -0.30 L; 95% CI, -0.08 to -0.69 L [P<.016]).

CONCLUSION: The use of spinal vests leads to decreases in lung function variables. The KED vest causes a greater decrease in FVC than the new KED-XT board, possibly because the crossed straps on the board compress the abdomen less.