Evidence-Based Medicine
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Crit Care Med. Aug 4, 2017; 6(3): 164-171
Published online Aug 4, 2017. doi: 10.5492/wjccm.v6.i3.164
Effects of intrapulmonary percussive ventilation on airway mucus clearance: A bench model
Lorena Fernandez-Restrepo, Lauren Shaffer, Bravein Amalakuhan, Marcos I Restrepo, Jay Peters, Ruben Restrepo
Lorena Fernandez-Restrepo, Lauren Shaffer, Bravein Amalakuhan, Marcos I Restrepo, Jay Peters, Ruben Restrepo, Division of Pediatric Critical Care, Division of Pulmonary and Critical Care, and Department of Respiratory Care, University of Texas Health Science Center and the South Texas Veterans Health Care System, San Antonio, TX 78240, United States
Author contributions: All authors contributed equally to the literature search, data collection, study design and analysis, manuscript preparation and final review.
Conflict-of-interest statement: None of the authors have any conflicts of interest.
Data sharing statement: There is no technical appendix for this manuscript because the study was extensively described within the manuscript itself. The statistical codes and the raw dataset were also included within the manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Bravein Amalakuhan, MD, Division of Pediatric Critical Care, Division of Pulmonary and Critical Care, and Department of Respiratory Care, University of Texas Health Science Center and the South Texas Veterans Health Care System, 7400 Merton Minter Blvd, San Antonio, TX 78240, United States. amalakuhan@uthscsa.edu
Telephone: +1-210-5675792 Fax: +1-210-9493006
Received: May 7, 2017
Peer-review started: May 10, 2017
First decision: May 23, 2017
Revised: June 1, 2017
Accepted: June 30, 2017
Article in press: July 3, 2017
Published online: August 4, 2017
Abstract
AIM

To determine the ability of intrapulmonary percussive ventilation (IPV) to promote airway clearance in spontaneously breathing patients and those on mechanical ventilation.

METHODS

An artificial lung was used to simulate a spontaneously breathing patient (Group 1), and was then connected to a mechanical ventilator to simulate a patient on mechanical ventilation (Group 2). An 8.5 mm endotracheal tube (ETT) connected to the test lung, simulated the patient airway. Artificial mucus was instilled into the mid-portion of the ETT. A filter was attached at both ends of the ETT to collect the mucus displaced proximally (mouth-piece filter) and distally (lung filter). The IPV machine was attached to the proximal end of the ETT and was applied for 10-min each to Group 1 and 2. After each experiment, the weight of the various circuit components were determined and compared to their dry weights to calculate the weight of the displaced mucus.

RESULTS

In Group 1 (spontaneously breathing model), 26.8% ± 3.1% of the simulated mucus was displaced proximally, compared to 0% in Group 2 (the mechanically ventilated model) with a P-value of < 0.01. In fact, 17% ± 1.5% of the mucus in Group 2 remained in the mid-portion of the ETT where it was initially instilled and 80% ± 4.2% was displaced distally back towards the lung (P < 0.01). There was an overall statistically significant amount of mucus movement proximally towards the mouth-piece in the spontaneously breathing (SB) patient. There was also an overall statistically significant amount of mucus movement distally back towards the lung in the mechanically ventilated (MV) model. In the mechanically ventilated model, no mucus was observed to move towards the proximal/mouth piece section of the ETT.

CONCLUSION

This bench model suggests that IPV is associated with displacement of mucus towards the proximal mouthpiece in the SB patient, and distally in the MV model.

Keywords: Mucus, Sputum, Mechanical ventilators, Percussion, Respiratory drainage, Breathing exercises

Core tip: Many respiratory conditions result in increased respiratory secretions and poor clearance, and are associated with poor patient outcomes. Intrapulmonary percussive ventilation (IPV) is an airway clearance technique that has become increasingly used over the last few years, however there is a paucity of data to support its efficacy. Using a simulated bench model, we found that IPV is associated with movement of mucus towards the mouth in the spontaneously breathing patient and thus supporting airway clearance. Interestingly, in patients on mechanical ventilation, IPV mainly displaced mucus distally into the lungs and thus may be harmful in this patient population.