Comparison of Negative Pressure Wound Therapy (NPWT) systems: Evaluation of Pressure Delivery in Presence of Dressing Leak.

Introduction: Recent studies have shown greater mean percentage wound volume and surface change with increased adherence to a -125mmHg negative pressure wound therapy regime¹. The objective of this study was to evaluate and compare the behavior of various NPWT systems when the system contains an air leak.

Materials/Methods: Three NPWT systems (NPWT-A^◊, NPWT -B^◊◊, NPWT -C^◊◊◊) were tested for 12 hours (3 units x 3 dressings each) using a simulated wound environment with induced dressing leak. Leak rates when NPWT-A was compared to NPWT-B and NPWT-C were 24 and 41 ccm, respectively. NPWT systems were tested at their respective default pressure setting (-125mmHg for NPWT -A^◊ and -80mmHg for NPWT -B^◊◊and NPWT -C^◊◊◊).

Results/Discussion: NPWT-A units consistently delivered therapy within spec without interruption for all 12hr tests. NPWT-B and NPWT-C systems exhibited on/off cycling resulting in average therapy delivery of 3.8 hours and 4.1 hours, respectively. During the test period, average pressures maintained at 24 ccm leak were -125.0mmHg for NPWT-A and -30.4mmHg for NPWT-B; average pressures maintained at 41 ccm leak were -124.2mmHg for NPWT-A and -30.8mmHg for NPWT-C.

Conclusion: Consistent delivery of NP has been shown to be related to wound progression¹. NPWT systems are not equivalent in performance. NPWT -A^◊ systems consistently delivered programmed therapy levels while exposed to a dressing leak. NPWT -B^◊◊ and NPWT -C^◊◊◊ systems were not capable of doing so under these test conditions.

^◊ ACTIV.A.C™ Therapy System (3M, San Antonio, TX), ^◊◊ PICO™ Therapy System (Smith & Nephew, England, UK); ^◊◊◊ PICO 7™ Therapy System (Smith & Nephew, England, UK)

References:

1. L Griffin and L Casillas, “A Patient-centered Remote Therapy Monitoring Program Focusing on Increased Adherence to Wound Therapy: A Large Cohort Study,” Wounds, 2018; 30(8) E81-E83.