Comparison of Negative Pressure Wound Therapy Systems with Wound Pressure-regulating Technology: Ability to Maintain Target Pressure Under Varying Test Conditions

Introduction: The ability of negative pressure wound therapy (NPWT) to deliver targeted negative pressure (NP) is challenged by complexities in moving exudate and air from the wound to the therapy unit. Wound pressure-regulating technology (PRT) monitors wound pressure and adjusts system parameters to ensure set therapy is being administered and fluid is being removed. This regular, controlled system assessment evaluates the potential for exudate pooling by measuring delivered NP. 

Objective: Evaluate ability of 3 NPWT systems to maintain target pressure under various test conditions. 

Materials and Methods: Three PRT-based NPWT systems (NPWT-A [ActiV.A.C.; KCI, an Acelity Company, San Antonio, TX], NPWT-B [V.A.C.Ulta; KCI, an Acelity Company], NPWT-C [Cardinal Health NPWT; Cardinal Health, Waukegan, IL]) were tested (3 units x 3 dressings each). Tests were performed at clinically relevant target pressures (-75 mm Hg, -125 mm Hg), with the units at 36” above the dressing and with a fluid bolus (60 mL) and simulated exudate added to the system (43 mL/hour). Pressures at each condition were assessed for 1 hour. Standard statistical methods were utilized. 

Results/Discussion: Both NPWT-A and NPWT-B maintained average pressures within ± 10 mm Hg of the target pressure while NPWT-C did not. At a target pressure of -75 mm Hg, the average pressure maintained was -72.3 mm Hg for NPWT-A, -72.0 mm Hg for NPWT-B, and -60.1 mm Hg for NPWT-C. These average pressures proved to be significantly different when comparing NPWT-A with NPWT-C (P < .001) and NPWT-B with NPWT-C (P < .001). 

At a target pressure of -125 mm Hg, the average pressure maintained was -122.8 mm Hg for NPWT-A, -120.7 mm Hg for NPWT-B, and -107.0 mm Hg for NPWT-C. These average pressures proved to be significantly different when comparing NPWT-A with NPWT-C (P < .001) and NPWT-B with NPWT-C (P < .001). 

Conclusion: These PRT-based NPWT systems are not equivalent in performance. NPWT-A and NPWT-B systems consistently delivered prescribed therapy levels under challenging experimental conditions; NPWT-C systems were not capable of doing so.

*This poster won 1st place in the Laboratory Research Category at the 2019 Symposium on Advanced Wound Care Fall.

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