History of Negative Pressure Wound Therapy (NPWT) Cheng Siu Wah Winnie, NC Stoma & Wound Care Unit Department of Surgery, QEH Starting in the 1970s numerous articles appeared in the Russian literature exploring the use of negative pressure for managing difficult to heal wounds. NPWT was developed at Wake Forest University, School of Medicine, and first marketed in the USA in (1995). (Willy, 2006) It has demonstrated efficacy for the treatment of acute as well as chronic wound NPWT_Stoma & Wound QEH 0 NPWT_Stoma & Wound QEH 1 Negative Pressure Wound Therapy (NPWT) A therapeutic non-invasive technique with using vacuum source to promote acute or chronic wound healing and fight infection. Consists of a wound dressing (gauze or foam), a drainage tube, an occlusive transparent film dressing, and connected to a vacuum source that supplies negative (subatmospheric) pressure. NPWT Applicable to Multiple Types of Wound Chronic, Acute & Sub-acute Wounds Ø Dehisced wounds, sternal or spinal wounds Ø Ulcers (such as pressure or diabetic or leg) Ø Partial & Full-thickness burns Ø Flaps and grafts; debridement wound Ø Enterocutaneous fistulas with known source Ø Traumatic wounds Ø Fasciotomy wounds associated with compartment syndrome. NPWT_Stoma & Wound QEH 2 NPWT_Stoma & Wound QEH 3 Contraindications to NPWT Untreated osteomyelitis Exposed arteries, veins, organs or nerves Necrotic tissue with eschar present Malignancy in wound (with exception of palliative care to enhance quality of life) Non-enteric and unexplored fistulas Anastomic sites Bleeding tendency NPWT_Stoma & Wound QEH 4 Optimise Wound Healing Moisture balance Ø Removes exudate and slough from the wound Ø Maintains a moist wound environment Ø Alleviates interstitial oedema Ø Decreases bacterial burden Cell stimulation Ø Increases blood flow Perfusion increased delivery of 0 2 and nutrients Ø Increases rate of granulation tissue formation Ø Stimulates proliferation of fibroblasts Ø Stimulates proliferation of endothelial cells NPWT_Stoma & Wound QEH 5 Ø Remodels connective tissue matrix NPWT_Stoma & Wound QEH 1
Optimise Wound Healing with Benefits of NPWT 1 Patient Ø Promote wound healthy tissue granulation Ø Promote wound contraction & epithelialization Ø Fight infection & protect from outside contaminants Ø Promote revascularization Ø Faster healing time Ø Lesser dressing material cost Ø Promote comfort Ø Lesser analgesic consumption as lesser pain experience Optimise Wound Healing with Benefit of NPWT 2 Nursing staff & Hospital Ø Cost effective Ø Fewer dressing change Ø Reduced need for extensive surgical closure procedures Ø Decrease nursing man-power attendance Ø Shorten hospitalization Ø Therapy may be continued at home with device Ø Lesser analgesic consumption as lesser pain experience Ø Promote rapport between nursing staff and patient NPWT_Stoma & Wound QEH 6 NPWT_Stoma & Wound QEH 7 NPWT - Devices Wound VAC KCI Ezcare, V1STA, Renasys Smith & Nephew Engenex Convatec Genadyne A4 Genadyne Biotechnologies Inc. Kalypto Kalypto Medical Medela Invia MoblVac Ohio Medical Prodigy Premco Medical System, Inc. Prospera Systems Medica Rents Svedman Systems Innovative Therapies Venturi System Talley Group Wound VAC KCI Svedman Systems Innovative Therapies NPWT_Stoma & Wound QEH 8 NPWT_Stoma & Wound QEH 9 Engenex Convatec MoblVac Ohio Medical Kalypto Kalypto Medical Prodigy Premco Medical System, Inc NPWT_Stoma & Wound QEH 10 NPWT_Stoma & Wound QEH 11 NPWT_Stoma & Wound QEH 2
NPWT Suction Force 50 125 mmhg Microvascular blood flow increase above baseline values Wackenfors et al, 2004 Use of NPWT in Surgical, QEH Abdominal dehisced wound Fournier s gangrene post-debrided wound Enterocutaneous fistulae (known origin) Leg ulcer Diabetic ulcer Pressure ulcer NPWT_Stoma & Wound QEH 12 NPWT_Stoma & Wound QEH 13 Gauze and Foam Dressing Flat & Round Drainage Tube NPWT_Stoma & Wound QEH 14 NPWT_Stoma & Wound QEH 15 NPWT Machine KCI V.A.C. Via Therapy System & Medela Vacuum System Medela Vacuum System KCI V.A.C. Via Therapy System provides 7 days therapy NPWT_Stoma & Wound QEH 16 NPWT_Stoma & Wound QEH 17 NPWT_Stoma & Wound QEH 3
Why does NPWT work? Mechanism of Action (MOA) Pressure gradient fluid shift Perfusion increased delivery of 0 2 and nutrients Biodurden management Mechanical forces stimulatory effect on cells Granulation tissue formation MOA Pressure Gradient A pressure gradient is achieved by creating a closed system and applying subatmospheric pressure to the wound which pulls material and cells from the wound bed Effect: Removal of surface wound fluid containing proinflammatory mediators Removal of fluid from within the tissues below the wound surface i.e. reduction of edema or interstitial fluid MOA Improved perfusion Wound healing requires increased levels of oxygen and nutrients. Blood flow to the wound bed and surrounding tissue may be decreased due to pressure on the capillaries from inflammation and edema. Effect: The negative pressure gradient decreases edema which decreases the direct pressure on the capillaries allowing for improved blood flow MOA Bioburden management Wound fluid is an excellent medium for bacterial growth. Increased levels of bacteria contribute to delayed and impaired healing in both acute and chronic wounds. Effect: Removal of wound fluid also removes bacteria from the surface of the wound Increased blood flow provides higher nutrient and oxygen levels to the wound Film dressing provides barrier to environmental contaminants MOA Mechanical forces Specific cells respond to mechanical stretching with an increase in proliferation and migration. Effect: The exact effects of mechanical stretching will requires further research Negative pressure pulls the wound margins together and reduces the wound volume, this may also assist with improved granulation tissue formation MOA Granulation tissue formation Granulation tissue is dependent on new capillary growth and deposition of connective tissue. Each MOA is essential for healing and the combined effects create a wound environment favorable for new tissue formation. NPWT_Stoma & Wound QEH 4
Antimicrobial Gauze Fills wound cavity Evenly distributes pressure Conduit for wound exudate Antimicrobial agent is Polyhexamethylene biguanide (PHMB) Always moistened prior to placement in the woundbed Dressing Change Procedure Change initial dressing at 48 hr. mark Frequency is dependent on exudate levels Ensure wound is responding positively to therapy Change dressing 2-3 times per week - No leakage present - Patient is comfortable Step 1 Cleanse wound bed and pat dry Step 2 Apply skin sealant and allow to dry Step 3 Lay non-adherent gauze across wound bed Step 4 - Cut the drain 1 inch shorter than the length of the wound. Curl the drain if using a channel or round drain. NPWT_Stoma & Wound QEH 5
Step 5 - Insert drain into wound bed. A layer of gauze must be placed between the drain and the wound bed. Step 6 - Apply Ostomy Strip Paste Step 7 - Fill wound with saline moistened antimicrobial gauze Step 8 - Place transparent dressing over the wound and seal Step 9 - Create a seal by pinching the strip paste Step 10 - Secure the Drain Tubing with BLUETAPE NPWT_Stoma & Wound QEH 6
Step 11 - Connect the drain to the canister and begin suction Finished Dressing Will have a raisin like appearance and be firm to the touch. Multiple Wounds Y-Connectors available to connect multiple wounds to a single unit. Abdominal Wound Hip Wound Case Sharing of Nursing Management on Fournier s Gangrene by NPWT (1) A 44 years old male patient suffering from Fournier s Gangrene over his lower abdomen and scortum. He had received three times necrotic tissue and skin excision or debridement, and abscesses incision and drainage. Surgeon consulted Stoma & Wound Nurse for wound assessment and management. The wound was extended from scortal upto right lower abdomen and further extensive to left flank region. It looked like a T-shaped wound. NPWT_Stoma & Wound QEH 39 Case 1: Before NPWT Case 1: NPWT Procedure 40 41 NPWT_Stoma & Wound QEH 7
Case 1: Wound Condition after NPWT Case 1: Final Outcome 42 43 Case Sharing of Nursing Management on Fournier s Gangrene by NPWT (2) Another 40 years old male patient suffering from Fournier s Gangrene over his perianal and scortal area. He had received three times necrotic tissue and skin excision or debridement, and abscesses incision and drainage. Surgeon consulted Stoma & Wound Nurse for wound assessment and management. The wound was extended from pubic to scortal and further to perianal region. It looked like a butterflyshaped wound. Case 2: Before NPWT 45 NPWT_Stoma & Wound QEH 44 Case 2: NPWT Procedure Case 2: Wound Contraction 46 47 NPWT_Stoma & Wound QEH 8
Case 2: Final Outcome Case Sharing of Nursing Management on Fournier s Gangrene by NPWT (3) 58 x 12 x 5 cm undermining@1h~7cm 48 49 Case 3: NPWT applied Case 3: Wound contraction 57 x 8 x 4 cm undermining@1h ~6cm 50 51 Case 3: Final Outcome Case 4: Fournier s Gangrene with Ventilator Care 52 NPWT_Stoma & Wound QEH 53 NPWT_Stoma & Wound QEH 9
Case 5: Fournier s Gangrene with Ventilator Care (old age) The incidence rate is increasing around the world 2. Centre for Health Protection, Department of Hong Kong (2010), just shortly from June to July 2010, there were four cases reported of FG while one was passed away 1. Despite of advanced management nowadays, the mortality rate is still high and averages at 20-30% 2. NPWT_Stoma & Wound QEH 54 55 From Nov 2009 to May 2011, eleven patients suffered from FG were received specialized nursing care from Stoma & Wound Care Nurse of SUR, QEH. Four with extensive post-debridement wound were treated with NPWT. Then wound reconstruction or closures were done by surgeon. These cases were back to community finally. 56 57 Retrospective review and analysis. Period: Nov 2009 to May 2011 Sample size: four cases of FG with extensive postdebridement wound Data Collection: medical history symptoms physical examination findings admission and laboratory tests timing and extent of surgical debridement antibiotic therapy advanced nursing management applied 58 Gender: all patients were male Mean age: 49 (ranged 43-62) Marrital Status: single Occupation: one was retired while three were still working (shipyard worker, transportation worker, reporter) Mean wound size: 1656.25 cm 3 59 NPWT_Stoma & Wound QEH 10
Possible Causative Source: Genitourinary: 25% ( associated with phimosis); Dermatology: 75% (associated along with skin disease such as eczema, psoriasis, skin texture changed over inner thigh region) Predisposing factors in association: 75% such as diabetes mellitus, immunosuppressed, smoking and alcoholism Organism: Polymicrobial Klebsiella species (75%), streptococcus species (50%), Enterococcus species (50%), Prevotella species (50%), and others such as Candida albicans, Acinebacter species, Coliform organisms, Diphtheroid bacilli, Escherichia coli, Bacteroides species, Gardaerella vaginalis, Peptococcus species, etc. 60 61 Antibiotic: Wide-spectrum antibiotics Surgery: Multiple debridement ~ 3.25 times per patient (ranged 2-4 times) Colostomy: 75% ICU admission: 50% Ventilator support: 25% Mean stay in ICU: 3 days Mean length of hospital stay: 58 days Mortality: 0% Survival rate: 100% as all cases were discharged back to community finally Involved cases with colostomy closure done already till recorded in Dec 2011. 62 63 Case Sharing of Nursing Management by NPWT Result findings compliable to journal studies. Better mortality rate. Using NPWT in a female patient with stage 3 pressure ulcer at sacral region. 64 NPWT_Stoma & Wound QEH 65 NPWT_Stoma & Wound QEH 11
Case Sharing of Pressure Ulcer Case Sharing of Pressure Ulcer NPWT_Stoma & Wound QEH 66 NPWT_Stoma & Wound QEH 67 Case Sharing of Pressure Ulcer Case Sharing of Nursing Management by NPWT Using NPWT in a female patient with post-op wound dehiscence. NPWT_Stoma & Wound QEH 68 NPWT_Stoma & Wound QEH 69 Case Sharing of Nursing Management by NPWT Case Sharing of Nursing Management on Fournier s Gangrene by NPWT NPWT_Stoma & Wound QEH 70 NPWT_Stoma & Wound QEH 71 NPWT_Stoma & Wound QEH 12
Other Cases Other Cases NPWT_Stoma & Wound QEH 72 NPWT_Stoma & Wound QEH 73 Others FDA Updates (Alerts) Complications: infection and bleeding Infection majority related to the retention of dressing pieces in the wounds. Bleeding occurred in patients who had blood vessel grafts those receiving anticoagulant, and during removal of dressings attached to the tissues. NPWT_Stoma & Wound QEH 74 FDA Recommendations Select patient for NPWT carefully Review the most recent device labelling and instructions Consideration of contraindications for certain wound types Assess patient risk factors Alert potentially life-threatening complications such as bleeding Prepare to take prompt action if they occur. FDA Website http://www.fda.gov/medicaldevices/safety/alertsand Notices/ucm244211.htm NPWT_Stoma & Wound QEH 13
References Ahearn, C. (2009). Intermittent NPWT and Lower Negative Pressures Exploring the disparity between Science and Current Practice: A Review. Ostomy Wound Management, 55(6), 22-28. Braakenburg, A., Obdeijin, M., Feitz, R., van Rooij, I.A., van Griethuysen, A.J. & Klinkenbijl, J.H. (2006). The clinical efficacy and cost effectiveness of the vacuum-assisted closure technique in the management of acute and chronic wounds: a randomized controlled trail. Plastic and Reconstructive Surgery, 118(2), 390-397. Kaplan, M., Banwell, P., Orgill, D.P., Ivature, R.R., Demetriades, D., Moore, F.A., Miller, P., Nicholas, J. & Henry, S. (2005). Guidelines for the Management of the Open Abdomen. HMP Communications. KCI. Retrieved from www.kci1.com/cs/satellite?c=kci_product_c&childpagename on 26/2/2011 Medela International, retrieved from www.medela.com/iw/en/healthcare/negative-pressure-woundtherapy/invia-vari on 26/2/2011 Philbeck, T.E., Whittington, K.T., Millsap, M.H., Boriones, R.B., Wight, D.G. & Schtoeder, W.J. (1999). The clinical and cost effectiveness of externally applied negative pressure wound therapy in the treatment of wounds in home healthcare Medicare patients. Ostomy Wound Management, 45(11), 41-50. Smith & Nephew Corporate. Retrieved from http://global.smithnephew.com/master/npwt_27568.htm on 26/2/2011 U.S. Food and Drug Administration (2011). FDA Safety Communication: update on serious complication associated with negative pressure wound therapy systems, issued on Frebury 24, 2011, retrived from http://www.fda.gov/medicaldevices/safety/alertsandnotices/ucm244211.htm#recommendations1 Wackenfors A, Sjogren J, Gustafsson R, Malmsjo M(2004) Effects of vacuum-assisted closure therapy on inguinal wound edge microvascular blood flow. Wound Repair and Regeneration 12:600-606 Willy, C. (2006). The theory and practice of vacuum therapy: Scientific basis, indications for use, case reports, practical advice. Ulm: Lindqvist Book-Publishing. Movie on NPWT Application 79 NPWT_Stoma & Wound QEH 78 Questions & Discussion Declared that all the information is for reference only and there is no contribution to any product distributors appeared in the content. Thank you for your attention! END NPWT_Stoma & Wound QEH 81 NPWT_Stoma & Wound QEH 14