How do Three Negative Pressure Wound Therapy Systems Compare for Accurate Pressure Delivery and Efficient Fluid Removal
TOPIC / INTRODUCTION: Negative pressure wound therapy (NPWT) systems must be able to effectively deliver therapy. The European Wound Management Association (EWMA) International Consensus Review states that NPWT systems containing an electronically-controlled feedback loop ensure maintenance of set pressure, guarantee the effectiveness of therapy and provide higher patient safety.1
PURPOSE / METHODOLOGY: Not all NPWT systems have the technical capability to meet all these standards, which can potentially lead to complications in wound healing. 2,3 The objective of this investigation was to use a simulated wound model to compare the ability of 3 commercially available NPWT systems to (1) maintain set pressure in a simulated wound bed when placed at different heights in relation to the “wound” and (2) to efficiently remove a 150 ml of simulated wound fluid. Testing was conducted at an independent third-party laboratory.
RESULTS: The experimental results supported that System M* and System K+ were able to consistently maintain the selected pressures (-125 & -75 mmHg) at the wound bed . System S> maintained close to target pressure (-120 mmHg) but was not as effective as Systems M. System M* efficiently cleared 89% of the 150ml fluid bolus in 20 minutes and consistently delivered set pressure (-125 mmHg) for the remainder of the two hour experiment.4 System K+ did not remove comparable fluid volume as System M* during the 2 hour evaluation and was unable to consistently maintain the -125 mmHg target pressure . System S> was also unable to remove more than 10ml (6.7%) of the fluid bolus. System S was not able to return target pressure (-120 mmHg) in the wound bed for the remainder of the 2 hour evaluation period.
CONCLUSION: It is critical that NPWT Systems deliver on all three system fundamentals (A, B, C). Systems that are unable to deliver set pressure to the wound bed (Fundamental A) and efficiently remove wound fluid (Fundamental B), may negatively impact the six mechanisms of action and hinder healing. NPWT systems that don’t efficiently remove fluid can lead to pooling of exudate which compromise maintaining a sealed wound environment (Fundamental C).
References
Apelqvis J, Willy C, Fagerdahl AM, et al. EWMA document: negative pressure wound therapy – overview, challenges and perspectives. J Wound Care. 2017;26(Suppl 3):S1–S113.Willy C. The Theory and Practice of Vacuum Therapy: Scientific Basis, Indication for Use, Case Reports, Practical Advice. Lindquist Publishing: 2006https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPCD/classification.cfm?id=5942Paglinawan R, Schwab P, Bechert K. Negative pressure wound therapy system Innovates standard of care via intelligent pressure control and dynamic exudate removal. Wounds. 2020;32(10):S1-S8.Paglinawan R, Schwab P, Bechert K. Novel NPWT system with innovative technology provides more accurate pressure delivery and superior fluid handling. Wounds. 2021;33(11):S3-S1
Trademark
* System M: Medela Invia® Liberty™ NPWT System with FitPad+ System K: 3M™ V.A.C.® Ulta Therapy System > System S: Smith & Nephew Renasys® Touch Therapy UnitNotes: Medela, Invia, Invia Liberty, Invia FitPad, Intelligent Pressure Control and Dynamic Exudate Removal are trademarks and/or registered trademarks of Medela Holding AG, Switzerland and are registered in the U.S. Patent and Trademark Office and elsewhere.
