Article Figures & Data
Figures
- Fig. 1.
Artificial airway cuff-inflation device. A: Manometer for continuous display of cuff pressure. B: Gas-sampling line, which connects the cuff-inflation device to the cuff pilot balloon. C: Connection between the cuff-inflation device and the flow-meter outlet. D: Pressure-relief valve adjustment for setting the cuff pressure.
- Fig. 2.
A: Cuff-inflation device test setup, which includes cuff pilot balloon, cuff-inflation syringe, standard analog pressure gauge, and pressure-calibration analyzer. A syringe and cuff inflator was attached to the endotracheal tube via a stopcock in the check valve at the end of the pilot tube. B: Setup for Part 1 of Test 1. The cuff-inflation device and calibration analyzer were connected via a single stopcock. The cuff-inflation device stopcock was adjusted Port A or Port B communication with the calibration analyzer. This test measured pressure within the cuff-inflation device, and compared this to the pressure delivered at the end of the gas-sampling line. C: The 3 stopcock ports used in the test hub. Port A and Port B are open while Port C is closed.
- Fig. 3.
The PressureEasy device was added between the pilot balloon and the test hub. It was evaluated for the effect on cuff pressure after adding 5 mL and 10 mL of air to the cuff after baseline inflation.
- Fig. 4.
Analysis of limits of agreement in cuff pressure for 2 cuff-inflation devices. The cuff-inflation-device measurements were compared to simultaneously obtained measurements from the calibration analyzer. The open triangles represent the measurements from one of the tested cuff-inflation devices, and the open diamonds represent the measurements from the other cuff-inflation device. The horizontal axis represents the mean of the arithmetic sum of the values measured with the calibration analyzer and the cuff-inflation device. The vertical axis represents the difference between the 2 measurements (calibration analyzer minus cuff-inflation device). The grey dashed line represents the mean difference, or bias. The black dotted lines represent the precision (± 2 standard deviations from the mean difference).
- Fig. 5.
Cuff-pressure changes after the addition of 5 mL and 10 mL of air into the cuff of 3 artificial airways, after initial baseline of 30 cm H2O established. The cuff-inflation device was compared to the PressureEasy device and the syringe-inflation method. The first and second bar in each group represent the cuff pressure (from the calibration analyzer) measured after the additional injection of 5 mL and 10 mL of air, with the Sheridan endotracheal tube, the Microcuff endotracheal tube, and the tracheostomy tube.
- Fig. 6.
Analysis of limits of agreement for measurements of exhaled tidal volume with direct patient-circuit connection to the test lung versus cuff inflation of 3 artificial airways with (A) the cuff-inflation device (open triangles) and (B) the syringe-inflation method (open squares). The horizontal axis represents the mean of the arithmetic sum of the values of VT measured with (A) direct patient circuit connect and the cuff-inflation device or (B) direct patient-circuit connection and the syringe-inflation method. The vertical axis represents the difference between the 2 measurements (A: calibration analyzer minus cuff-inflation device, and B: calibration analyzer minus syringe-inflation method). The grey solid line represents the mean difference, or bias. The black dotted lines represent the precision (± 2 standard deviations from the mean).
