Mechanical behaviors of Flutter VRP1, Shaker, and Acapella devices.

BACKGROUND Flutter VRP1, Shaker, and Acapella are devices that combine positive expiratory pressure (PEP) and oscillations. OBJECTIVES To compare the mechanical performance of the Flutter VRP1, Shaker, and Acapella devices. METHODS An experimental platform and a ventilator, used a flow generator at 5, 10, 15, 20, 26, and 32 L/min, were employed at angles of -30°, 0°, and +30° to evaluate Flutter VRP1 and Shaker, whereas Acapella was adjusted at intermediate, higher, and lower levels of resistance, including positive expiratory pressures (PEP) along with air outflow rates and oscillation frequencies. RESULTS When the relationships between pressure amplitudes of all air flows were analyzed for the 3 devices at low and intermediate pressures levels, no statistically significant differences were observed in mean pressure amplitudes between Flutter VRP1 and Shaker devices. However, both devices had different values from Acapella, with their pressure amplitude values being higher than that of Acapella (P = .04). There were no statistically significant differences in PEP for the 3 angles or marks regarding all air flows. The expected relationships between variables were observed, with increases in PEP, compared to those of air flows and resistance. Nevertheless, there was a statistically significant difference in frequency of oscillation between these devices and Acapella, whose value was higher than those of Flutter VRP1 and Shaker devices (P = .002). At intermediate pressure levels, the patterns were the same, in comparison to low pressures, although the Acapella device showed frequencies of oscillation values lower than those of Flutter VRP1 and Shaker (P < .001). At high pressures, there were no statistically significant differences among the 3 devices for frequency of oscillations. CONCLUSIONS The Flutter VRP1 and Shaker devices had a similar performance to that of Acapella in many aspects, except for PEP.