Retained and excessive secretions can lead to disorders like atelectasis but therapies like Percussionaire’s IPV therapy—recently acquired by Sentec—can improve patient outcomes.

By Bill Pruitt, MBA, RRT, CPFT, FAARC

In the late 1980s and early 1990s, Dr Forrest Bird developed an innovative means of providing intrapulmonary percussive ventilation or IPV therapy to address issues with atelectasis, excessive and/or retained secretions, and mucus plugs. His company, Percussionaire, went on to produce several FDA-approved medical devices for use in patients. Recently, Sentec (Therwil, Switzerland), known for their development of transcutaneous CO2 monitoring, acquired the Percussionaire company and its portfolio of IPV therapy products that serve all ages of patients in both hospital and home environments. 

This article will explore the issues with atelectasis and retained/excessive secretions, some of the therapies developed to address these issues with a focus on IPV therapy, the research that has been published about airway clearance and other issues that IPV therapy can address, and what the future will bring for Sentec as they move forward with the acquisition of Percussionaire. 

Retained Secretions and Atelectasis 

For many patients with lung disease, retained secretions are problematic and can lead to a cascade of issues including mucus plugging with obstruction of the airways causing atelectasis and loss of volume, sometimes hyperinflation or air trapping, increased work of breathing, hypoxemia, hypercarbia, and an increased risk of infection. 

Atelectasis can also be linked to post-operative situations. Loss of lung volume can occur during a procedure when the lung is manipulated or compressed, and postsurgical pain may cause a patient to avoid coughing and/or prevent them from taking deep breaths.

These issues are especially problematic in cases involving the thorax (ie, open-heart, bypass surgeries), abdominal surgery, and patients receiving mechanical ventilation.1 Excessive and retained secretions can occur in patients with COPD, bronchiectasis, pneumonia, asthma, or cystic fibrosis, and in burn patients, etc. Excessive and retained secretions are also an issue in patients with a weak or absent cough, often found in neuromuscular diseases (ie, Guillain-Barré syndrome, Amyotrophic lateral sclerosis or ALS, Duchenne muscular dystrophy, etc).1-2 

Other Technology and Therapies 

For many years, manual therapy using chest percussion and postural drainage with or without vibration (referred to as chest physical therapy, CPT), or various breathing and coughing techniques have been used to clear secretions. These approaches are time-consuming and usually required much coaching or assistance to perform. More recently, many devices have been developed with the goal of moving secretions or improving cough including items such as vibratory positive expiratory pressure devices (VPEP), high frequency chest wall oscillation/compression machines (HFCWO), insufflation/exsufflation units (to mimic a deep breath and cough maneuver using positive/negative pressure) and oscillation and lung expansion (OLE) devices.3 

In 1991, Percussionaire received the 510(K) authorization from the FDA to begin marketing IPV therapy, a new and innovative way to address secretions and atelectasis. This technology has been incorporated into all of the Percussionaire devices and is being carried forward now with Sentec. 

Sentec IPV Therapy: Phasitron 5 

All IPV therapy systems rely on a unique device called the Phasitron 5 which contains a sliding venturi. The movement of the venturi is the key to the device’s unique ability to combine three components of therapy to improve gas exchange capacity: percussion, entrainment, and high-velocity flow. As the venturi slides forward and back, mini-bursts of air called pulsatile flow are delivered into the patient through various patient interfaces (including mouthpiece, mask, endotracheal tube, tracheostomy tube, or connected inline with a ventilator) and travel down the airways. 

The Phasitron allows the flow to dynamically adjust to the resistance of the lung and protects the lung from exposure to too much pressure and volume. Increasing resistance will automatically slow down or stop the entrainment of flow into the venturi and change the amplitude of the mini-burst of air that is delivered to the lung. “If resistance decreases, the venturi will entrain more flow, but amplitude (pressure) will decrease. If resistance increases, the opposite is true with amplitude increasing but flow (volume) decreasing.”4 

The Phasitron 5 patient circuit is a single-patient, multi-use, disposable device that is replaced according to facility protocols. The Phasitron’s unique sliding venturi is the key feature of IPV therapy and is not found in any other device on the market.

IPV Therapy 

The frequency of the pulses of air and the amplitude or driving force of flow behind each pulse can be adjusted on all Sentec IPV therapy devices. The mini-bursts of air percuss the airways from within, dislodging mucus stuck to the airway walls, breaking mucus plugs free, and dislodge debris in the airways. As the high velocity pulsatile flow moves through and past these obstructions and into the distal airways, the distal areas that have lost volume or have become atelectatic begin to fill and recruitment occurs. Demand CPAP, an additional feature found in some IPV therapy devices, further augments this recruitment and helps maintain open lung areas. The responding expiratory flow moves mucus, secretions, and debris upward from the distal airways toward more central airways where it can be coughed and expelled by the patient or be suctioned. 

The recommended treatment time for one session is 15 to 20 minutes and a typical schedule will start on a Q6 to Q8-hour time frame, decreasing in frequency as the patient improves. For more severe cases, the duration and frequency of IPV therapy sessions can be customized. Over time, the IPV therapy recruits areas of atelectasis, removes secretions, debris and mucus plugs, and maintains the open lung to allow improved gas exchange and healing to occur. The treatment must be given with humidity to avoid drying the airways and mucus, so treatments are given with saline through the Phasitron’s integrated nebulizer. 

Robert Tero Sr, RRT-NPS, CPFT, territory manager at Sentec, has used the IPV therapy devices for many years. In discussing who would be a good candidate for IPV therapy Tero said, “Any patient with secretion issues, post-operative atelectasis, mucus plugging, or lung recruitment needs can benefit from IPV therapy.” He has worked with patients who have COPD, asthma, bronchiectasis, RSV, etc, and has seen dramatic changes, often within the first few treatments, and sometimes after just one. Most patients have a very positive response within 24 to 48 hours of treatment with IPV therapy.

In adjusting the settings to mobilize secretions, Tero explained that increasing the frequency works to address this, while decreasing the frequency aims more at resolving atelectasis and recruiting the lung. The lower frequency provides a larger pulse volume and can also help in removing CO2. Increasing the pulsatile flow tends to increase mean airway pressure and increase the chest “wiggle” or vibrations through the airways that can be palpated, auscultated, and observed with the patient. “My approach for first-time patients is to start in a gentle mode (higher frequency), then after several minutes begin to be more aggressive (lower frequency).” 

One issue Tero noted is that some clinicians new to IPV therapy use too short of a treatment session. “The standard delivery time is 15 to 20 minutes . . . or in the more severe cases the IPV therapy can be longer. Some patients need an hour-long session, others may need treatments to be performed more or less often. Some patients will take a few treatments to work up to a treatment duration and intensity that generates the result the therapist is looking for. If therapists stop therapy too soon, they may not see as much in the way of positive results. It all depends on the patient and the underlying problems—IPV therapy gives caregivers the ability to tailor the approach to the situation.” 

He added: “Patients using a mouthpiece must be coached to take an easy, relaxed breath and to keep their cheeks tight. Looseness in the cheeks can dampen the pulsatile breaths and the desired effects in the airway.” 

Essentially, the goals and mechanisms of the Sentec IPV therapy systems and Phasitron air flow are threefold: 

  1. Percussion: The movement of the venturi within the Phasitron creates unique percussive bursts that break up secretions and mucus plugs;
  2. Entrainment: Dynamically responding to airway resistance, the movement of the sliding venturi effectively entrains air to recruit and maintain the opened lung areas; and 
  3. High-velocity flow: Accesses distal airways beyond obstructions or secretions, detaches secretions from airway walls, and enables the expiratory flow necessary to move secretions outward. 

What’s New

Sentec is in the process of releasing a new device called the IPV 1. Tom Russell, RRT, National Strategic Account and Partnership manager, Respiratory Solutions at Sentec, is very familiar with the clinical applications of IPV therapy. When talking about the acquisition of Percussionaire and the IPV therapy technology, Russell said, “This unit will provide more user-friendly connections between the device and Phasitron and will be easier for respiratory therapists to both learn and use.” 

Russell continued, describing the advantages of IPV therapy in this way, “Clinicians have been trying to address the different issues of reversing atelectasis and recruiting areas of the lungs, clearing secretions and mucus plugs, and addressing hyperinflation by using several different approaches and different devices. It is like putting pieces of the puzzle together to address poor gas exchange. IPV therapy and, in particular, the sliding venturi within the Phasitron, addresses all of these issues at the same time and using one comprehensive approach.” 

Bob Cormier, president of Sentec Inc, added, “This technology has a long history of use and is safe and effective. Existing evidence, while limited, shows the IPV therapy devices succeed in reducing exacerbations, improving gas exchange, reducing length of stay, and improved patient adherence to the plan of care. With the new IPV 1, we have an improved, easy-to-use device that offers all the advantages of the Phasitron technology that Percussionaire’s customers have come to depend on.” 

He continued, “We want to take this technology into the hospital and home, and have both clinicians and patients see the dramatic changes that can occur with IPV therapy. Many locations across the nation and around the world have had extensive experience and tremendous success with all ages and in many different patient scenarios. We want more clinicians and patients to benefit from IPV therapy.” 

Research on IPV Therapy 

IPV therapy has been available since the 1990s and research has been published from around its introduction until very recently and is continuing. Two problems in the published research on IPV therapy (and in almost all other research on techniques to accomplish secretion mobilization) is that: 

  1. The sample sizes are too small; and
  2. There is too much heterogeneity (too much variation in protocols, in selecting populations, in device settings being used, in treatment times, in outcomes, etc). 

These two issues prevent researchers from reaching strong conclusions or official recommendations.6-8 That being said, the research findings that are available offer insights into the effects of IPV therapy and collectively point to the need for well-designed, large, multicenter studies on IPV therapy in accomplishing the goals of secretion mobilization, treatment of at-electasis, improvement in gas exchange, decreasing length of time receiving mechanical ventilation, reducing length of stay, decreasing cost, etc. (For a look at some of the research that has been published, please see the following references: 6-7, 9-14.) 


Intrapulmonary percussive ventilation therapy using Phasitron technology is gaining strong support in healthcare centers around the world and has research that supports its use, although more study is needed. This approach to secretion clearance, correcting atelectasis, and improving gas exchange has anecdotal evidence that is clearly remarkable. As often implied in current publications, some well-designed studies could potentially help establish this as a recommend-ed therapy in all ages and in a variety of situations. This technology is unique and appears to be able to accomplish much in improving the outcomes of patients who need help. Sentec is planning on taking IPV therapy to the next level.

Bill Pruitt, MBA, RRT, CPFT, FAARC, is a writer, lecturer, and consultant. Bill has over 40 years of experience in respiratory care in a wide variety of settings and has over 20 years teaching at the University of South Alabama in Cardiorespiratory Care. Now retired from teaching, Bill continues to provide guest lectures, participates in podcasts, and writes professionally. For more information, contact [email protected].

Additional Reading

For a look at some of the research that has been published, here is a short list giving the lead author (year published) and the source followed by a summary of important points from the paper (in this author’s opinion). The complete citation for each article is found in the References:

  • Garafolo (2023). J of Clinical Monitoring and Computing. End-expiratory lung impedance and PaO2/FiO2 increased significantly after the treatment, suggesting alveolar recruitment and improved oxygenation.9
  • Lauwers (2018) Pediatric Pulmonology.  This systematic review found that, “IPV is considered safe in spontaneously breathing and mechanically ventilated children and infants, although the presence of a skilled supervisor is advised.” The article’s conclusion states: “IPV is a safe and effective technique for airway clearance.”10
  • Hasan (2021) J of the Intensive Care Society. In this review, the conclusion states, “The therapeutic value of IPV in airway clearance and treating pulmonary atelectasis remains inconclusive, requiring further investigations.”11
  • Conomon (2021) Resp Care J. This bench study compared performance of the Hill-Rom Volara and the Percussionaire IPV-2C in mobilizing simulated mucus (determined by weight before and after treatment) with and without mechanical ventilation. Without ventilation, the Volara removed 17.54% compared to the removal of 61.94% of total weight using the IPV 2C. With ventilation the Volara removed 4.89% compared to the removal of 55.33% of initial weight using the IVP 2C.12
  • Nicolini (2018) Inter J of COPD. Both HFCWO and IPV improved daily life activities and lung function in patients with severe COPD. However, IPV demonstrated a significantly greater effectiveness in improving some PFT results linked to the small bronchial airways obstruction and respiratory muscle strength and scores on health status assessment scales (BCSS and CAT) as well as a reduction of sputum inflammatory cells compared with HFCWO.7  
  • Reychler (2018) Resp Care J. “The main findings showed that IPV improves gas exchange during exacerbation and could reduce the hospital length of stay for patients with COPD. In subjects with cystic fibrosis, neither lung function nor other parameters were improved. The systematic use of IPV as an airway clearance technique in chronic obstructive airway diseases is not supported by sufficiently strong evidence to recommend routine use in this patient population.”6
  • Meyers (2020) Resp Care J. “The use of IPV in postoperative neonates with cardiovascular surgery is a safe practice because it did not cause any unanticipated complications and impact the patient’s vital signs, MAP and SpO2.”13
  • Cavari (2022) Open J Pediatr Child Health. “In our study, the mean length of stay was 6.18 days for the control group, versus 4.13 days for the IPV group. In this small, prospective single center cohort of severely ill infants with bronchiolitis, no side effects were observed with IPV treatment. While our findings failed to show significant beneficial effects, there is a trend toward a decreased need for invasive ventilation and improved CO2 clearance. Future prospective studies should aim to further evaluate the effect of IPV in this population.”14

  1. Branson RD. Secretion management in the mechanically ventilated patient. Respiratory care. 2007 Oct 1;52(10):1328-47. 
  2. Camela F, Gallucci M, Ricci G. Cough and airway clearance in Duchenne muscular dystrophy. Pediatric respiratory reviews. 2019 Aug 1;31:35-9.
  3. Deakins K, Chatburn RL. A comparison of intrapulmonary percussive ventilation and conventional chest physiotherapy for the treatment of atelectasis in the pediatric patient. Respiratory care. 2002 Oct 1;47(10):1162-7.
  4. From the Percussionaire White Paper, “A comparison of HFPV, HFOV, and HFJV”, Lockwood D. Accessed April 2023.
  5. IPV-2C Quick Start Guide (Mouthpiece/Mask) from Accessed March 2023.
  6. Rechler G, Debier E, Contal O, Audag N. Intrapulmonary percussive ventilation as an airway clearance technique in subjects with chronic obstructive airway diseases. Respiratory care. 2018 May 1;63(5):620-31.
  7. Nicolini A, Grecchi B, Ferrari-Bravo M, Barlascini C. Safety and effectiveness of the high-frequency chest wall oscillation vs intrapulmonary percussive ventilation in patients with severe COPD. International journal of chronic obstructive pulmonary disease. 2018 Feb 16:617-25.
  8. Hassan A, Lai W, Alison J, Huang S, Milross M. Effect of intrapulmonary percussive ventilation on intensive care unit length of stay, the incidence of pneumonia and gas exchange in critically ill patients: A systematic review. PloS one. 2021 Jul 28;16(7):e0255005.
  9. Garofalo E, Rovida S, Cammarota G, Biamonte E, Troisi L, et al. Benefits of secretion clearance with high frequency percussive ventilation in tracheostomized critically ill patients: a pilot study. Journal of Clinical Monitoring and Computing. 2023 Jan 6:1-8.
  10. Lauwers E, Ides K, Van Hoorenbeeck K, Verhulst S. The effect of intrapulmonary percussive ventilation in pediatric patients: A systematic review. Pediatric Pulmonology. 2018 Nov;53(11):1463-74.
  11. Hassan A, et al. Feasibility and safety of intrapulmonary percussive ventilation in spontaneously breathing, non-ventilated patients in critical care: A retrospective pilot study. Journal of the Intensive Care Society. 2021 May;22(2):111-9.
  12. Conomon D, and Alturo L. High Frequency Percussive Airway Clearance Utilizing Two Devices in Simulation of Mucous Clearance, Without Spontaneous Breathing, Both With and Without Mechanical Ventilation. Resp Care. October 2021, 66 (Suppl 10) 3584084;
  13. Meyers MN, et al. Is It Safe to Use Intrapulmonary Percussive Ventilation on Post-Operative Neonates With Cardiovascular Surgery? Resp Care. October 2020, 65 (Suppl 10) 3444414;
  14. Cavari Y, et al. Intrapulmonary percussive ventilation for children with bronchiolitis on non-Invasive Ventilation support. Open J Pediatr Child Health. 2022;7(1):025-30.