Comparison of Intrapulmonary Percussive Devices Using a Bench Top Mechanical Ventilation Design

Abstract

Background:

There are many secretion mobilization devices available for patient care. These devices differ in their designs and functions: manual or mechanical, with or without adjustable settings, high or low cost. The objective of this study was to compare the effectiveness between two mechanical secretion mobilization devices. The Percussive-Neb 2.0 (P-Neb) uses high pressure and high flow and it has multiple settings including soft and hard for secretion mobilization and lung expansion. The MetaNeb (M-Neb) also has two settings; continuous positive expiratory pressure (CPEP) for lung expansion and continuous high frequency oscillation (CHFO) for secretion clearance.

Methods:

A test lung simulation unit (Model 2600i Michigan Instruments, Grand Rapids, MI) and an endotracheal tube (ETT) were used to simulate a mechanically ventilated patient. The settings on the test lung simulation unit were adjusted to minimally create secretion mobilization. A mucus-like substance Polyox (Education Innovations, Bethel, CT) was made and diluted to a mucus consistency and placed at the 20 cm mark of the ETT. For the P-Neb, a “mouthpiece” was made from small PVC pipes so that it would fit onto the ETT. This mouthpiece was placed between the P-Neb and proximal end of ETT. The setting for P-Neb was set to “hard.” For the M-Neb, it was attached to the proximal end of the ETT. For both devices, the distal end of ETT was attached to the test lung simulation unit. Both devices were run for five trials each with a continuous duration of 6 minutes. The ETT was positioned at a 35 degree angle leading to the test lung simulation unit mimicking the position of ETT on an intubated patient. The distance of mucus movement was determined by the difference between the start position (20 cm mark of ETT) and the end position (after 6 minutes).

Results:

Figure 1 shows the average composite data between these two devices. The graph shows that both P-Neb and M-Neb are effective in secretion mobilization. The difference in distance mobilized between P-Neb and M-Neb is about 0.5 cm.

Conclusions:

Both P-Neb and M-Neb can be an effective secretion mobilization device during mechanical ventilation. Not able to use human subjects and actual secretions are two limitations of this study.

Figure 1 Average distance (5 trials each) of secretion mobilization between Percussive Neb 2 (top) and MetaNeb (bottom)