HFCWO on Pneumonic Respiratory Failure (HFCWOonAFR)

The Instantaneous Effects of High-Frequency Chest Wall Oscillation on Patients With Acute Pneumonic Respiratory Failure Receiving Mechanical Ventilation

BACKGROUND: Endotracheal intubation and prolonged immobilization of patients receiving mechanical ventilation may reduce expectoration function. High frequency chest wall oscillation (HFCWO) may ameliorate airway secretion movement; however, the vigorous oscillation may influence ventilator settings and change instantaneous cardiopulmonary responses. The aim of this study was to investigate these issues. METHODS: Seventy-three patients aged >20 years who were intubated with mechanical ventilation for pneumonic respiratory failure were recruited and randomly classified into two groups (HFCWO group, n=36; and control group who received conventional chest physical therapy (CCPT), n=37). HFCWO was applied with a fixed protocol, while CCPT was conducted using standard protocols. Both groups received sputum suction after the procedure. Changes in ventilator settings and the subjects' responses were measured at pre-set intervals and compared within groups and between groups.

Study Overview

• Status: Completed
• Conditions: Pneumonia; Acute Respiratory Failure
• Intervention / Treatment: Device: Vest Airway Clearance System Model 105; Device: placebo intervention

Detailed Description

Pneumonia may increase bronchial secretion and decrease mucociliary function, thereby causing lung atelectasis. Patients with acute pneumonic respiratory failure receiving mechanical ventilation may therefore have a large amount of pulmonary secretions, thereby worsening bronchial hygiene, oxyhemoglobin saturation and ventilation-perfusion match. Cough function is paramount for expectoration; however, coughing is not practical for patients with endotracheal intubation and sedation. High frequency chest wall oscillation (HFCWO) may dislodge airway secretions as efficiently as conventional chest physical therapy (CCPT). However, pneumonia is not currently an indication for chest physical therapy.

HFCWO compresses and relaxes the chest wall to generate an oscillated volume from the lungs, mimicking a "mini-cough" and producing shear stress at the air-mucus interface which changes the sputum rheology, thereby improving ventilation distribution, gas mixing, and forced expired volume in one second. Most studies that have reported no significant effects have focused on mortality, hospital stay, lung function or BODE (a multidimensional 10-point scale of body mass index, severity of airflow obstruction, dyspnea rated with the modified Medical Research Council, and exercise capacity evaluated with the Six-Minute Walk Distance) score. However, these outcome measurements are not associated with the immediate effects of chest physical therapy and may be affected by other factors such as disease severity.

Using the amount of sputum as the outcome measurement of HFCWO is not strongly recommended. However, immediate cardiopulmonary changes in HFCWO have not been studied in patients receiving mechanical ventilation, although this measurement is more explicit than lung function and BODE score, as they are impractical in these patients. Changes in ventilator settings caused by HFCWO are a concern when the patients receive both treatments simultaneously. The aim of this study was to investigate the effect of HFCWO on pneumonic subjects with acute respiratory failure receiving mechanical ventilation by evaluating immediate cardiopulmonary changes and changes in the initial ventilator settings.

Methods

The investigators conducted this comparative prospective randomized controlled single-blinded study at a university hospital. Adult subjects with pneumonia complicated with acute respiratory failure requiring endotracheal intubation and mechanical ventilation were consecutively recruited from a medical intensive care unit (ICU) (20-bed capacity). Pneumonia was defined as the presence of new or progressive pulmonary infiltrates and two of the following: body temperature > 38.3C or < 36C; white blood cell count > 12,000/mL or < 4,000/mL; purulent tracheal secretions without other signs of infection requiring antimicrobial treatment. Acute respiratory failure was defined as a sudden decrease in PaO2 < 60 mm Hg (or arterial oxyhemoglobin saturation < 90%) with or without PaCO2 > 45 mm Hg.17-19 All of the patients had sufficient sputum production to require the physician to order airway secretion clearance. Disease severity was assessed by Acute Physiology and Chronic Health Evaluation (APACHE) II score. Adverse events were evaluated by the investigators and reported to the institutional review board. The exclusion criteria were pregnancy, pneumothorax, manifest hemoptysis, unstable hemodynamics, increased intracranial pressure, and those undergoing major cardiac, thoracic or abdominal surgery.

All of the eligible patients had acute pneumonic respiratory failure and received endotracheal intubation and mechanical ventilation, and all signed informed consent forms. The patients were randomly allocated to the study group (HFCWO) or the control group (CCPT), as the efficacy of bronchial hygiene for both HFCWO and CCPT is comparable4. The primary investigators were blinded to which procedure the patients received. The local institutional review board of Chung Shan Medical University Hospital approved this study (No. CS13004). The experimental research was conducted in compliance with the Helsinki Declaration.

To prevent vomiting during or after chest care, all of the subjects underwent the procedure one hour before or two hours after feeding via a nasogastric tube. Inhalation therapy was performed with an aerosolized solution of 6 mL of half saline via the ventilator before HFCWO or CCPT.

HFCWO was performed using a VestTM Airway Clearance System Model 105 (Hill-Rom, St. Paul, Minnesota) connected to a vest via two flexible tubes by trained nurses who were blinded to the purpose of the study. All of the nurses had been well trained in how to perform both HFCWO and CCPT before the study, as these procedures are routinely performed by nurses at the investigators institution. HFCWO was applied to each subject at a frequency of 10-12 Hz and a pulse pressure setting of 1-2 selected from a scale ranging from 1 to 10 (arbitrary units) for 15 minutes. The patients receiving HFCWO were placed in a semi-upright sitting position, and the patients undergoing CCPT received cup-hand percussion with the hands positioned 3 inches from the chest, striking the chest with a waving movement while they were placed in right and left decubitus positions for 5-10 minutes each1. Following HFCWO or CCPT, suction was performed immediately via an endotracheal tube.

Changes to the initial ventilator settings during HFCWO were recorded by the trained nurses by checking the ventilator panel before and at 5, 10 and 15 minutes during HFCWO. The variables included peak airway pressure (Ppeak), positive-end expiratory pressure (PEEP), respiratory rate (RR), fraction of inspired oxygen (FIO2), inspiratory time, and sensitivity settings.

Changes in the patients' cardiopulmonary responses were measured before and at 5, 10 and 15 minutes during oscillation, and at 15 minutes after sputum suction. The measurement protocol for the CCPT group was the same as for the HFCWO group, except no measurements were taken at 5 or 10 minutes during percussion because it was not possible for a single nurse to perform percussion and record measurements at the same time.

Rapid shallow breathing index (RSBI) was calculated as follows:

RSBI = breathing frequency (breaths/minute)/tidal volume (liters) (1) Oxyhemoglobin saturation was measured using a pulse oximeter (SPO2). Data were presented as mean ± standard deviation (SD) or median (interquartile range). For each outcome variable, comparisons were planned a priori. A paired t or unpaired t test was used for within-group or between-group comparisons. For non-normal data, the Mann-Whitney test was used. The chi-square test or Fisher's exact test was used to compare proportions of categorical variables between the two groups. A p value less than 0.05 was considered to be statistically significant. All statistical analyses were performed using SAS software version 9.3 (SAS Institute Inc., Cary, NC) and Microcal Origin version 4.0 (Northampton, MA, USA).

• Study Type: Interventional
• Enrollment (Actual): 73
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• acute pneumonic respiratory failure and received endotracheal intubation and mechanical ventilation,
• having sufficient sputum production to require the physician to order airway secretion clearance

Exclusion Criteria:

• pregnancy
• pneumothorax
• manifest hemoptysis
• unstable hemodynamics
• increased intracranial pressure
• those undergoing major cardiac, thoracic or abdominal surgery

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: HFCW oscillation; HFCWO was performed using a Vest Airway Clearance System Model 105 (Hill-Rom, St. Paul, Minnesota). HFCWO was applied to each subject at a frequency of 10-12 Hz and a pulse pressure setting of 1-2 selected for 15 minutes. The patients receiving HFCWO were placed in a semi-upright sitting position. Following HFCWO, suction was performed immediately via an endotracheal tube. Changes to the initial ventilator settings during HFCWO were recorded before and at 5, 10 and 15 minutes. The variables included peak airway pressure, positive-end expiratory pressure, respiratory rate, fraction of inspired oxygen, inspiratory time, and sensitivity settings. Following HFCWO, suction was performed immediately via an endotracheal tube.	Device: Vest Airway Clearance System Model 105; HFCWO for 15 minutes then sputum suction.; Other Names: HFCW oscillation; HFCWO
Placebo Comparator: placebo intervention; the patients undergoing CCPT received cup-hand percussion with the hands positioned 3 inches from the chest, striking the chest with a waving movement while they were placed in right and left decubitus positions for 5-10 minutes each. Following CCPT, suction was performed immediately via an endotracheal tube.	Device: placebo intervention; CCPT for 15 minutes then sputum suction.; Other Names: CCPT; CC physical therapy

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
peak airway pressure	mm Hg	15 minutes
mean airway pressure	mm Hg	15 minutes
minute ventilation	liters per minute	15 minutes
respiratory rate	breaths per minute	15 minutes
tidal volume	miniliters	15 minutes
rapid shallow breathing index	breaths per minute/liter	15 minutes
SpO2		15 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
FiO2= inspired oxygen fraction		15 minutes
respiratory rate	times per minute	15 minutes
airway pressure setting	mm Hg	15 minutes
inspiratory time	second	15 minutes
heart rate	beat per minute	15 minutes
blood pressures	mm Hg	15 minutes

Collaborators and Investigators

• Sponsor: Chung Shan Medical University
• Investigators: Principal Investigator: Ming-Lung Chuang, Chung Shan Medical University

Publications and helpful links

General Publications

• Allan JS, Garrity JM, Donahue DM. High-frequency chest-wall compression during the 48 hours following thoracic surgery. Respir Care. 2009 Mar;54(3):340-3.
• Chaisson KM, Walsh S, Simmons Z, Vender RL. A clinical pilot study: high frequency chest wall oscillation airway clearance in patients with amyotrophic lateral sclerosis. Amyotroph Lateral Scler. 2006 Jun;7(2):107-11. doi: 10.1080/14660820600640570.
• Clinkscale D, Spihlman K, Watts P, Rosenbluth D, Kollef MH. A randomized trial of conventional chest physical therapy versus high frequency chest wall compressions in intubated and non-intubated adults. Respir Care. 2012 Feb;57(2):221-8. doi: 10.4187/respcare.01299. Epub 2011 Jul 12.
• Plioplys AV, Lewis S, Kasnicka I. Pulmonary vest therapy in pediatric long-term care. J Am Med Dir Assoc. 2002 Sep-Oct;3(5):318-21. doi: 10.1097/01.JAM.0000028225.84012.3B.
• McCool FD, Rosen MJ. Nonpharmacologic airway clearance therapies: ACCP evidence-based clinical practice guidelines. Chest. 2006 Jan;129(1 Suppl):250S-259S. doi: 10.1378/chest.129.1_suppl.250S.
• Whitman J, Van Beusekom R, Olson S, Worm M, Indihar F. Preliminary evaluation of high-frequency chest compression for secretion clearance in mechanically ventilated patients. Respir Care. 1993 Oct;38(10):1081-7.
• Jones AP, Rowe BH. Bronchopulmonary hygiene physical therapy for chronic obstructive pulmonary disease and bronchiectasis. Cochrane Database Syst Rev. 2000;(2):CD000045. doi: 10.1002/14651858.CD000045.
• Zahm JM, King M, Duvivier C, Pierrot D, Girod S, Puchelle E. Role of simulated repetitive coughing in mucus clearance. Eur Respir J. 1991 Mar;4(3):311-5.
• Dosman CF, Jones RL. High-frequency chest compression: a summary of the literature. Can Respir J. 2005 Jan-Feb;12(1):37-41. doi: 10.1155/2005/525813.
• Darbee JC, Kanga JF, Ohtake PJ. Physiologic evidence for high-frequency chest wall oscillation and positive expiratory pressure breathing in hospitalized subjects with cystic fibrosis. Phys Ther. 2005 Dec;85(12):1278-89.
• Goktalay T, Akdemir SE, Alpaydin AO, Coskun AS, Celik P, Yorgancioglu A. Does high-frequency chest wall oscillation therapy have any impact on the infective exacerbations of chronic obstructive pulmonary disease? A randomized controlled single-blind study. Clin Rehabil. 2013 Aug;27(8):710-8. doi: 10.1177/0269215513478226. Epub 2013 Mar 15.
• Park H, Park J, Woo SY, Yi YH, Kim K. Effect of high-frequency chest wall oscillation on pulmonary function after pulmonary lobectomy for non-small cell lung cancer. Crit Care Med. 2012 Sep;40(9):2583-9. doi: 10.1097/CCM.0b013e318258fd6d.
• Chuang ML, Lee CY, Chen YF, Huang SF, Lin IF. Revisiting Unplanned Endotracheal Extubation and Disease Severity in Intensive Care Units. PLoS One. 2015 Oct 20;10(10):e0139864. doi: 10.1371/journal.pone.0139864. eCollection 2015.
• King M, Phillips DM, Gross D, Vartian V, Chang HK, Zidulka A. Enhanced tracheal mucus clearance with high frequency chest wall compression. Am Rev Respir Dis. 1983 Sep;128(3):511-5. doi: 10.1164/arrd.1983.128.3.511.
• Chatburn RL. High-frequency assisted airway clearance. Respir Care. 2007 Sep;52(9):1224-35; discussion 1235-7.
• Chuang ML, Chou YL, Lee CY, Huang SF. Instantaneous responses to high-frequency chest wall oscillation in patients with acute pneumonic respiratory failure receiving mechanical ventilation: A randomized controlled study. Medicine (Baltimore). 2017 Mar;96(9):e5912. doi: 10.1097/MD.0000000000005912.

Study record dates

Study Major Dates

• Study Start: February 1, 2014
• Primary Completion (Actual): November 1, 2015
• Study Completion (Actual): November 1, 2015

Study Registration Dates

• First Submitted: April 24, 2016
• First Submitted That Met QC Criteria: April 29, 2016
• First Posted (Estimate): May 2, 2016

Study Record Updates

• Last Update Posted (Estimate): May 2, 2016
• Last Update Submitted That Met QC Criteria: April 29, 2016
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Keywords: acute respiratory failure; chest wall oscillation; airway secretion
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Respiratory Insufficiency
• Other Study ID Numbers: CS13004

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No