Comparing Negative Pressure Wound Therapy with Instillation vs. Standard wound care to treat postoperative wound infections.

Surgical wounds are the most common wounds seen in daily clinical practice and
are associated with a variety of complications such as bleeding and dehiscence.
Surgical site infections are the most common complication, and the high rates
of POWI leads to additional treatment, prolonged hospital stay, patient
discomfort, and as a result of this a substantial increase in costs. Negative
Pressure Wound Therapy with Instillation (NPWTi) use is growing as a
therapeutic approach to treat postoperative wound infections (POWIs), yet high
quality evidence of its effectiveness is lacking. Our hypothesis is that time
to complete wound healing in patients with a POWI who receive NPWTi will be
shorter than in patients receiving standard wound care (i.e., NPWT and/or
conventional wound care).

To investigate if the use of initial NPWTi leads to a faster wound healing
compared to standard wound care only in patients with a POWI.

An investigator-initiated multicentre randomized controlled trial. Patients
will be randomized to NPWTi or standard wound care with a 1:1 ratio. An a
priori power analysis and an anticipated dropout rate of 10% indicates that 223
patients per group are needed, totalling 446 patients to be able to detect a
14-day reduction in wound healing time.

NPWTi (after debridement if needed). The wound will be covered with an
open-cell foam and an occlusive drape. During repeated cycles, the wound bed
will be automatically soaked with 0.9% normal saline for 15 minutes followed by
negative pressure cycle at -125 mmHg for 2-3 hours; cycle length depending on
the bioburden of the wound. The foam and drape are changed every 2-3 days (1
treatment period). At least two treatment periods of 2-3 days need to be
completed before switch to standard NPWT (preferred) or conventional dressing.

Comparison: Standard wound care (after debridement if needed). This involves
the use of NPWT and/or conventional dressings, depending on local standards.
NPWT involves open-cell foam and occlusive drape with negative pressure
treatment but without intermittent topical delivery of instillation fluid and
soaking cycles. Conventional dressings are gauze-based or occlusive dressings
and will be used until the wound is completely healed.

Patients will be asked to report pain scores (using a Numeric Rating Scale
(NRS) scored for the first two weeks daily, and during dressing changes for the
first four weeks) (in total: approximately 30 minutes). They will be also be
asked to complete the EQ-5D-5L health status questionnaire, the iMTA Medical
Consumption Questionnaire (iMCQ) and the iMTA Productivity Cost Questionnaire
(iPCQ) at baseline, and after 30 & 90 days, 6 and 12 months after inclusion)
(approximately 20 minutes per measurement), and to take photos of their wound
at baseline, and after 30 & 90 days, 6 and 12 months after inclusion) and
during dressing changes (approximately 5 minutes per measurement). NPWTi, NPWT
and conventional wound care are all used as a therapeutic aid to treat POWIs,
and are considered as safe interventions.