Efficiency of New Smart Instillation Technology With Negative Pressure Wound Therapy in Managing Complex Chronic and Surgical Wounds: A Case Series

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NPWTi-d with a topical wound solution provides the benefits of conventional NPWT and facilitates wound cleansing and removal of infectious materials.^1,2 Regular cleansing with solutions helps to dilute and solubilize infectious material, facilitate removal of exudate and debris from the wound bed, and promote granulation tissue development.³ 

NPWTi-d has become an important adjunct therapy at Lions Gate Hospital (North Vancouver, British Columbia), a level III trauma center, to help manage complex wounds containing large areas of devitalized tissue. However, therapy utilization has been limited in some cases due to perceptions of complexity among nurses and other clinicians tasked with caring for these wounds.^4,5 Determining the appropriate volume of solution to instill can be challenging because of varying wound size and wound exudate levels. Health care providers rely heavily on their experience to make these estimates, and this process can be stressful and time-consuming for staff in terms of both setup and training.⁶

A new smart technology is available in certain NPWTi-d systems that estimates and delivers a volume of topical wound solution based on automated measurements of the drawdown volume of the applied negative pressure foam dressing. Initial experience with this smart instillation feature in 4 complex wounds containing large areas of devitalized tissue and/or yellow fibrinous slough is reported.

Four patients with large complex wounds (Table) were treated in a level III trauma center. Systemic antibiotics were administered as appropriate. Suitable analgesics were administered as needed. The pressure injury was debrided, and the other wounds were not. 

The NPWTi-d system (3M Veraflo Therapy; Solventum Corporation) was applied similarly for all patients. An ROCF-CC (3M Veraflo Cleanse Choice Dressing or 3M Veraflo Cleanse Choice Complete Dressing; Solventum Corporation) was cut to size, placed in the wound, and then covered with a silicone-acrylic hybrid drape (3M V.A.C. Dermatac Drape; Solventum Corporation). Tubing was connected from the dressing to the NPWTi-d unit. 

Normal saline was the instilled topical wound solution for all patients. On-screen instructions were followed during NPWTi-d unit setup. The smart instillation button (3M Smart Instill Feature; Solventum Corporation) was selected, which prompted the user to enter the size of the canister, and then negative pressure was initiated. The device performed a seal check and determined a volume of saline to be instilled based on the drawdown volume of the foam dressing. The device-determined volume was accepted each time without adjustments. This automated smart feature, rather than manual estimation, was used to determine the instillation volume at least once per week. The volume was then recorded in the patient’s chart for quick entry into the NPWTi-d unit if needed during setup at the next dressing change. Default settings of 10-minute dwell time, followed by 2 hours of −125 mm Hg negative pressure were selected for all patients. ROCF-CC dressings were changed 3 times per week. Therapy was switched to conventional NPWT as appropriate when the wound bed was covered with clean granulation tissue. 

The new smart feature streamlined several therapy initiation steps that were previously more time-consuming and complicated. Automation reduced guesswork and led to faster NPWTi-d setup. The automatically determined instilled solution volume decreased over time as the wound size decreased. There were no observed instances of dressing overfilling, periwound maceration, or saline leaks during therapy for any wound. The average NPWTi-d duration was 17.0 days (range, 6–30 days). All wounds were converted to clean granulating wounds during therapy.

Case 1

A 62-year-old male presented with a pressure injury on his right posterior thigh. The wound was debrided, and NPWTi-d was initiated. After 30 days of NPWTi-d, the wound was clean and considerably smaller. Therapy was stepped down to NPWT, and the patient was discharged to community care (Figure 1).

Case 2

A 23-year-old male presented with a deep infected soft tissue wound originating from an injection site. Systemic antibiotics were initiated. NPWTi-d was used for 22 days, until the wound was covered with healthy granulation tissue. Therapy was switched to traditional NPWT for 1 week, after which a split-thickness skin graft was applied. NPWT was used as a bolster over the skin graft, and graft take was 100% (Figure 2).

Case 3

A 73-year-old female presented with a hematoma on her right shin after a fall. The eschar was lifted off, and the wound bed was irrigated. NPWTi-d was used for 10 days. The patient was discharged to community care (Figure 3).

Case 4

A 90-year-old female presented with midline dehiscence from a bowel resection and ileostomy. Antibiotics were initiated. NPWTi-d was used for 6 days. The patient died due to causes unrelated to wound care (Figure 4).

In this patient series, smart technology simplified NPWTi-d usability by automatically determining and delivering topical wound solution and adjusting the volume as the wound size decreased. An option to adjust or accept the automated volume estimate was displayed prior to initiating negative pressure, as well as an option to estimate by typing in the wound dimensions. To simplify the setup process for the staff, the automated estimate and default settings were used without any adjustments or manual entry of wound dimensions for all wounds.

No overfilling was observed during therapy for any of the 4 patients. As evidenced by positive wound healing progression and no saline or air leaks, the smart feature appeared to estimate adequate volume of topical wound solution throughout therapy. This is consistent with results of a 2023 study by Kim et al⁶ that evaluated the automated estimator of solution volume in 23 patients. Their results suggested that the smart feature used a conservative estimate that provided sufficient instillation volume in 65% of cases, but that often resulted in underfilling in wounds with a volume greater than 120 cm³. Underfilling was sometimes observed in the current study, but it did not appear to affect the wound healing outcome. 

A simple formula of multiplying the wound area by 0.2 mL has been suggested to manually estimate instillation volume (mL) during NPWTi-d.⁵ In this investigator’s experience, compared to the automated method, this manual calculation method may result in more leak alarms due to various measurement inconsistencies, nonuniform wound depth, and tunneling or undermining. The automated estimation method is favored to help simplify the setup process and potentially reduce alarms caused by compromised dressing seals related to overfilling. 

Wound care patients are increasingly more complex, with a greater number of comorbidities, making their wounds more difficult to treat and increasing demands on clinicians’ time.⁷ The smart instill feature was part of a software upgrade that also included updated default therapy settings, animated video troubleshooting, instill phase postpone feature, and a therapy inactive alarm time delay. In the 4 cases discussed in this report, use of this technology addressed nursing staff challenges by saving time and making it easier for less experienced caregivers to gain confidence and proficiency with the therapy. Device-controlled solution delivery may also reduce frequency of saline leaks, which in turn could save nursing time, reduce frustration, and enhance patient quality of life. Additionally, no skin preparation products were needed with the use of the silicone-acrylic hybrid drape, which also saved time.

The current study is limited by the small size, with only 4 patients. Larger controlled studies are needed to determine the quantitative and qualitative effect of smart instill NPWTi-d with respect to nursing efficiency and clinical outcomes. Future studies that compare automated vs. manual estimates of instillation solution volume could help inform on the effects of this feature on patient and caregiver satisfaction as well as wound outcomes, particularly for wounds in difficult anatomic locations and of diverse dimensions.

The smart instillation feature was easy to use, and it automatically determined, distributed, and adjusted the volume of instilled solution at setup and as the wound size decreased. Positive patient outcomes in this series suggest that an adequate volume of saline was instilled to facilitate regular cleansing and hydromechanical removal of devitalized tissue through the ROCF-CC dressing.

Affiliation: Lions Gate Hospital, North Vancouver, BC, Canada

Disclosure: The author is a paid consultant for Solventum Corporation. This information was presented at the Symposium on Advanced Wound Care Spring/Wound Healing Society Meeting held May 14-18, 2024, in Orlando, FL.

Acknowledgment: The author thanks Maritza Quintero (Solventum Corporation) for providing editorial assistance with this manuscript. 

Ethical Approval: Data were collected via patient charts or medical records, which included patient consent. The data and photographs are void of any identifying characteristics.

Correspondence: Rosemary Hill, BSN, CWOCN, NSWOC, WOCC(C); Lions Gate Hospital, Vancouver Coastal Health, 231 15th St E, North Vancouver, BC V7L 2L7 Canada; Rosemary.hill@vch.ca

Manuscript Accepted: October 8, 2024