Break the cycle of patient-ventilator asynchrony

When your patient needs ventilatory assistance but is trying to regulate their own breathing, it can be a challenge for the ventilator to sync up with the patient’s respiratory rhythm. The result is patient-ventilator asynchrony (PVA), an issue that impacts 24 percent of ICU patients.1

PVA occurs when the ventilator delivers inspiratory and expiratory times that don’t match a patient’s breathing pattern. This can be especially prevalent in patients with certain conditions, such as chronic obstructive pulmonary disease (COPD), or individuals undergoing a spontaneous breathing trial (SBT). Both scenarios can make PVA hard to detect and resolve — even for the most experienced clinicians.

Explore how the IE Sync™ software option for the Puritan Bennett™ 980 ventilator can help curtail patient-ventilator asynchrony with its fine-tuned approach to triggering and cycling.


How is asynchrony detected? Why is it often missed in patients with COPD and those undergoing a spontaneous breathing trial?


One common way for clinicians to detect PVA is to look for clues on ventilator waveforms. However, if lung and airway conditions for patients with COPD and patients undergoing SBT change from moment to moment due to secretions and variations in effort, it may impact the way patient waveforms look.

Identifying specific irregularities within irregular waveforms can require significant training and practice.2 It’s not a skill that’s easily honed, even by the most experienced clinicians. In addition, detecting PVA takes time and vigilance at the bedside. Fellows, residents, respiratory therapists, and nurses who can recognize PVA are not always able to be in the room to do so. That’s why PVA may go unnoticed.


What can happen to a patient when asynchrony isn’t managed properly?


PVA can happen for several reasons. If the patient needs to inhale before they finish exhalation, the patient may experience a longer than normal time between the beginning of inspiration and breath delivery from the ventilator. Even worse, the ventilator may not respond at all to the patient’s inspiratory effort.

On the other hand, the patient may inhale and receive two ventilator breaths without being able to exhale at all in between them. These asynchronies can cause dyspnea, anxiety, delirium, diaphragm and lung injury, and are also associated with a longer duration of mechanical ventilation.3

Seventy-one percent of ventilated patients in the ICU show signs of agitation at least once during their stay.4 Clinicians may respond by increasing sedation in an effort to alleviate agitation in patients.4 But when PVA is the cause of patient agitation, increasing sedation won’t solve the problem and may make it worse by delaying a patient’s liberation from the ventilator.

Deep sedation can lead to diaphragmatic atrophy within 18 hours.5 Sedation can also cause complications, including neurological changes, disorientation, and delirium, that can interfere with patient cooperation during ventilator liberation attempts.4 The result can be prolonged ventilator days and ICU stays and a higher cost of care.4


How can IE Sync™ software help minimize asynchrony?


With the IE Sync™ software option installed, the Puritan Bennett™ 980 ventilator offers an additional trigger type selection on the ventilator setup screen when invasively ventilating adult patients with Pressure Support or Volume Support.

IE Sync™ software does not require any additional catheters or sensors. Instead, it uses the pressure and flow measurements that the ventilator is already measuring to estimate changes in intrapleural pressure as a means of recognizing the onset and end of a patient’s inspiratory effort. This noninvasive triggering and cycling software can be particularly valuable for providing timely breath triggering and cycling on patients with airflow obstruction and weak inspiratory efforts.6,7

IE Sync™ software is the newest addition to the Puritan Bennett™ 980 ventilator synchrony suite of software options designed to help clinicians provide synchronous ventilatory support for spontaneously breathing patients.

Learn more about our software options for various patient types

Puritan Bennett™ 980 ventilators are built to help clinicians improve ventilation outcomes and quality of care for patients. Each ventilator can be customized with advanced technology focused on supporting patient-ventilator synchrony. Software options, safety features, and accessories to fit a variety of patient needs — from neonate to adult — are available:

  • Puritan Bennett™ PAV+™ software allows adult patients to direct the rate, depth, and timing of each breath.
  • Puritan Bennett™ Leak Sync software automatically detects and compensates for fluctuating leak sizes, which may result in a decreased risk of breath trigger and cycle asynchronies and help keep patients at a more desirable work of breathing.8

By improving the patient-ventilator relationship, clinicians can potentially make their patients more comfortable and help them breathe more naturally, engaging the respiratory muscles9 and facilitating mechanical ventilation liberation.10-12 


Please pay close attention to warnings and their associated consequences as described in the Puritan Bennett™ 980 ventilator operator’s manual. The ventilator system is not intended to be a comprehensive monitoring device and does not activate alarms for all types of conditions. Do not operate the ventilator in a magnetic resonance imaging (MRI) environment. Risks associated with using a mechanical ventilator include but are not limited to hypoxemia, hypercarbia, hypocarbia, and infection.


Contact your local Medtronic representative to ask about upgrading your Puritan Bennett™ 980 ventilators with the IE Sync™ software option.


1. Zhou Y, Holets SR, Li M, et al. Etiology, incidence, and outcomes of patient-ventilator asynchrony in critically-ill patients undergoing invasive mechanical ventilation. Sci Rep. 2021;11(1):12390. Published 2021 Jun 11. DOI:10.1038/s41598-021-90013-z

2. Colombo D. Efficacy of ventilator waveforms observation in detecting patient–ventilator asynchrony. Crit Care Med. 2011;39(11):2452-7.

3. Esperanza J, Sarlabous L, de Haro C, Rudys Magrans, et al. Monitoring Asynchrony During Invasive Mechanical Ventilation. Respiratory Care. Jun 2020, 65 (6) 847-869; DOI: 10.4187/respcare.07404

4. Siegel MD. Management of agitation in the intensive care unit. Clin Chest Med. 2003:24(4):713–725.

5.Levine S, Nguyen T, Taylor N, Friscia ME, Budak MT, Rothenberg P, Zhu J, Sachdeva R, Sonnad S, Kaiser LR, Rubinstein NA, Powers SK, Shrager JB. Rapid disuse atrophy of diaphragm fibers in mechanically ventilated humans. N Engl J Med. 2008 Mar 27;358(13):1327-35. DOI: 10.1056/NEJMoa070447. PMID: 18367735.

6. PB980 Triggering Performance Study: Flow triggering vs IE Sync™ triggering. Engineering report RE00222008 RevA, Carlsbad, CA.

7. PB980 Triggering and Cycling Performance Study, Flow Method versus IE Sync™ Method. Engineering report RE00229880 RevA, Carlsbad, CA.

8. Oto J, Chenelle CT, Marchese AD, Kacmarek RM. A comparison of leak compensation in acute care ventilators during noninvasive and invasive ventilation: a lung model study. Respir Care. 2013;58(12):2027-2037. doi:10.4187/respcare.02466

9. Bosma KJ, Read BA, Bahrgard Nikoo MJ, Jones PM, Priestap FA, Lewis JF. A Pilot Randomized Trial Comparing Weaning From Mechanical Ventilation on Pressure Support Versus Proportional Assist Ventilation. Crit Care Med. Jun 2016;44(6):1098-108. DOI:10.1097/ccm.0000000000001600

10. Kampolis CF, Mermiri M, Mavrovounis G, Koutsoukou A, Loukeri AA, Pantazopoulos I. Comparison of advanced closed-loop ventilation modes with pressure support ventilation for weaning from mechanical ventilation in adults: A systematic review and meta-analysis. J Crit Care. Nov 25 2021;68:1-9. DOI: 10.1016/j.jcrc.2021.11.010

11. Kataoka J, Kuriyama A, Norisue Y, Fujitani S. Proportional modes versus pressure support ventilation: a systematic review and meta-analysis. Ann Intensive Care. Dec 10 2018;8(1):123. DOI:10.1186/s13613-018-0470-y

12. Ou-Yang LJ, Chen PH, Jhou HJ, Su VY, Lee CH. Proportional assist ventilation versus pressure support ventilation for weaning from mechanical ventilation in adults: a meta-analysis and trial sequential analysis. Crit Care. Sep 14 2020;24(1):556. DOI:10.1186/s13054-020-03251-4

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