Quantitative_Research_Report

Relationship of Poor Nutrition in Regards to Negative Pressure Wound Therapy Carinna Yakush November 21, 2010 Grand Canyon University NRS-433V Relationship of Poor Nutrition in Regards to Negative Pressure Wound Therapy Introduction “Pressure ulcers (PrUs) are the most frequent secondary condition in patients with spinal-cord injury (SCI)” (Bauman, Collins, Ho, Powell, Spungen 2010, pp.1). Nurses come in contact with pressure ulcers no matter what field they work in. Healthcare professionals are constantly and consistently researching and putting new efforts into the field to try to prevent, as well as speed the healing of pressure ulcers. Many different components are taken into consideration when dealing with pressure ulcer treatment and prevention, including bed positioning, age, diseases, the patient’s immune system, wound care, and nutrition. Nursing focuses on all of these aspects as nurses take care of the whole patient, not just the specific problem initially presented. The objective of the research study was to evaluate the efficacy for the healing of pressure ulcers in spinal-cord injury patients receiving negative-pressure wound therapy (NPWT) compared to those individuals with spinal-cord injuries receiving standard wound care alone (NoNPWT). The specific research question to be answered in this study can be stated as: Was there a difference in the proportion of spinal-cord injury patients receiving NPWT treatment and NoNPWT treatment regarding a decrease in wound surface area after the 28 day observational study. The hypothesis states there will be no significant difference in the wound surface area of the pressure ulcers between the spinal-cord injury patients with pressure ulcers in the NPWT treated group and the NoNPWT treated group. The treatment of pressure ulcers with negative pressure wound therapy (NPWT) is considered the independent variable and the dependent variable would be the extent of the wound surface area of the pressure ulcers. Discussion Nutrition is a primary area of concern when dealing with pressure ulcers and their statistics. Laboratory values such as albumin and prealbumin levels may be helpful when determining status of a patients’ hydration. Essential nutrients such as fat, carbohydrates, protein, and amino acids are vital to appropriate health maintenance and a secure pressure ulcer healing time. Some amino acids are essentials when dealing with certain types of trauma situations. “L-Arginine is 32% nitrogen and in some studies has been shown to increase concentrations of hydroxyproline, which is an indicator of collagen deposition and protein in the wound site” (Collins, Dorner, Posthauer, 2010, pp. 33). According to the research found in the study, those patients’ with spinal-cord injuries can develop pressure ulcers from a number of different causes, including impaired blood flow, impaired mobility, loss of sensation to affected areas, improper nutrition, excessive moisture, and many other factors. The authors implied that use of NPWT includes potential benefits such as increased blood flow and granulation, enhanced epithelial cell migration, decreased bioburden, removal of exudate and excess interstitial fluid, mechanical approximation of wound edges, and decreased shear forces and mechanical trauma to the wound, which can be exacerbated by frequent dressing changes (Bauman, et al, 2010, pp. 3). They also conclude that the overall evidence for NPWT treatment of wounds is inconsistent and weak. The study targeted the area where pressure ulcers most likely occur in SCI patient’s, the pelvic region. For the study design, data was collected from a feasibility study from the Department of Veterans Affairs Cooperative Study Program, study #535 (Bauman, et al 2010, pp. 6). Fourteen SCI centers participated in the study mentioned. The centers were all regional and tertiary centers which provided SCI patients with inpatient care with Stage 3 and 4 pressure ulcers. All data used in this study was collected over a 28 day period called a screening phase where no medication or experimental interventions were used. During the screening phase standard wound care was provided including turning, low-air-loss mattresses, dressing changes, debridement, cleaning, and biophysical modalities. The NPWT therapies were used according to the doctors’ discretions after they decided which patient’s would be good candidates for the study. A threat to the internal validity of the study includes the doctors’ choice of patients for the study. They picked specific persons to use the NPWT. Also, only 11 out of the 14 centers were used, so it was not completely randomized. The same amount of men and women and specific ages were not used for each type of pressure ulcer treatment, forming an external validity threat. The sample is large enough in that information was able to be analyzed with specific results. The continuous variable comparisons between the two groups were compared using unpaired t-tests. All other categorical variables were compared between the groups by chi-square analyses (Bauman, 2010, pp. 15). T-tests were used to compare the variables within each group from day 1 to day 28. The changes in the surface area regarding the pressure ulcers were calculated and the reported a mean as a percentage of occurrence. The sample was representative of the target population as all patients were from SCI hospitals, and went through a series of exclusion criteria’s including life expectancy <12 mos, history of AIDS or immunologic diseases, CAD, suspicion of skin cancer, history or radiation, etc. (Bauman et al, 2010, Table 1). All data was collected by a study coordinator at each specific site by digital imaging technology the Verg Videometer Measurement Documentation (VeV MD) software. The software program measured and calculated length, width, total surface area of wounds via digital camera. The instruments used were appropriate for the study because it eliminates unwanted bias, where if it was a person or persons collecting the data they may have their own input to the look or measurements. All users of the imaging software were trained at the same time to ensure reliability. Each site had the study approved by their local institution review board before initiation began, and informed consent was collected from participants. Conclusion The data showed no significant differences related to the healing outcomes of the stage 3 or 4 pressure ulcers in the pelvic region on the spinal-cord injury patients between either NPWT and NoNPWT groups over the 4-week observation. The data analyses were appropriate for answering the hypothesis because they used statistical analysis. A specific timeframe was used, and the same digital observations were used for all participants. The only significant difference in outcomes between the two groups was in regards to the laboratory values finding a lower serum albumin level in those receiving NPWT treatments and the wounds that worsened over the time frame, which suggested poor nutrition. Strengths of this study include the fact that this is the largest trial placed on multicenters regarding spinal-cord injury patient’s and pressure ulcer treatments to date. This is also the first study comparing SCI patients when adding NPWT to recommended standards of care. All subjects received optimized care and frequent assessments by wound care professionals. Another strength was the use of the VeV MD system, which has been proven more reliable than manual measurements. There was no corporate bias or commercial funding with the study. There are two weaknesses included in this study. The first was the lack of depth measurements or consideration of improvement in undermining or tunneling in the authors’ analysis (Bauman, et al, 2010, pp. 19). Manual wound depths were recorded but not included in the assessment outcomes. The second weakness was that prealbumin levels were not collected during the screening phase. This makes no levels available to be analyzed. Prealbumin levels could have helped with the nutritional assessment. More research studies and discussions are needed regarding the effects of NPWT and wound healing of pressure ulcers. Future studies may look into using the VeV MD for accuracy, but make sure nutritional status is assessed ahead of time accurately, including laboratory values before, during, and after for follow-up. Patient’s who are living with spinal-cord injuries and are at risk for or currently have pressure ulcers need continuous education and repetition of education for themselves and their families regarding treatment and prevention of ulcers. References Bauman, W., Collins, J., Ho, C., Powell, H., Spungen, A. (2010). Poor Nutrition is a Relative Contraindication for Negative Pressure Wound Therapy for Pressure Ulcers: Preliminary Observations in Patients with Spinal Cord Injury. ADVANCES IN SKIN & WOUND CARE. Vol. 23 No. 11. Lippincott, Williams, & Wilkins. Beck, C., Polit, D. (2010) Essentials of Nursing Research: Appraising Evidence for Nursing Practice (Seventh Edition). Wolters Kluwer. Philidelphia: Lippincott. Collins, N., Dorner, B., Posthauer, M. (2010). Nutrition: A Critical Component of Wound Healing. ADVANCES IN SKIN & WOUND CARE. Vol. 23 (12) December 2010, pp. 560-572. Lippincott, Williams, & Wilkins. Poor Nutrition Is a Relative Contraindication to Negative Pressure Wound Therapy for Pressure Ulcers: Preliminary Observations in Patients with Spinal Cord Injury Ho, Chester H. MD; Powell, Heather L. MD; Collins, Joseph F. ScD; Bauman, William A. MD; Spungen, Ann M. EdD Author Information Chester H. Ho, MD, Site Investigator, Cooperative Study #535, Department of Veterans Affairs, Clinical Science Service; Chief, Spinal Cord Injury, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio; and Assistant Professor, Department of Physical Medicine and Rehabilitation, Case Western Reserve University, Cleveland, Ohio. Heather L. Powell, MD, Spinal Cord Injury Medicine Fellow, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio; and Spinal Cord Injury Medicine Fellow, Department of Physical Medicine and Rehabilitation, Case Western Reserve University, Cleveland, Ohio. Joseph F. Collins, ScD, Senior Biostatistician, Cooperative Study #535, Department of Veterans Affairs, Clinical Science Service; and Director, Cooperative Studies Program Coordinating Center, VA Medical Center, Perry Point, Maryland. William A. Bauman, MD, Chairman, Cooperative Study #535, Department of Veterans Affairs, Clinical Science Service; Director, RR&D Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, New York; and Professor, Departments of Medicine and Rehabilitation Medicine, Mount Sinai School of Medicine, New York. Ann M. Spungen, EdD, Co-Chair, Cooperative Study #535, Department of Veterans Affairs, Clinical Science Service; Associate Director, RR&&D Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, New York; and Associate Professor, Departments of Medicine and Rehabilitation Medicine, Mount Sinai School of Medicine, New York. |   | ABSTRACT |   | OBJECTIVE: To assess the efficacy of negative-pressure wound therapy (NPWT) for healing of pressure ulcers (PrUs) in individuals with spinal-cord injury (SCI). |   | DESIGN: Multicenter, 28-day observational study. |   | SETTING: Ten Veterans Affairs Medical Center SCI centers. |   | PATIENTS: Eighty-six SCI inpatients with Stage III/IV pelvic PrUs. |   | INTERVENTIONS: Standard wound care with NPWT versus standard wound care alone (NoNPWT). |   | MAIN OUTCOME MEASURES: Change in wound surface area (WSA) using the Verg Videometer Measurement Documentation software. |   | MAIN RESULTS: The proportion of patients demonstrating a decrease in WSA (healing subgroup) was not significantly different between the NPWT (n = 33) and NoNPWT (n = 53) groups (67% vs 70%, respectively). In the healing subgroup, there was no significant difference between the NPWT versus NoNPWT groups in WSA decrease (-43 ± 22% vs -50% ± 26%, not statistically significant). Similarly, in the nonhealing subgroup, there was no significant difference between NPWT and NoNPWT groups (31% ± 26% vs 32% ± 34%). In the NPWT group, the nonhealing subgroup (11/33) had significantly lower serum albumin levels than the healing subgroup (22/33) (2.9 ± 0.4 vs 3.3 ± 0.5 mg/dL, P < .05). In the NoNPWT group, there was no significant difference in serum albumin levels between the healing versus nonhealing subgroups (3.2 ± 0.3 vs 3.2 ± 0.3 mg/dL). |   | CONCLUSION: In SCI patients with Stage III/IV pelvic PrUs, NPWT did not significantly influence the rate of healing. Additionally, in malnourished individuals (albumin <3.0 mg/dL), NPWT was not efficacious. Healing outcomes in the NPWT group were significantly influenced by albumin levels, whereas no such disparity was noted between the healing and nonhealing PrUs for the NoNPWT group. Nutritional status appears to be important in the effectiveness of NPWT. |   | |   | Back to Top |   | INTRODUCTION |   | Pressure ulcers (PrUs) are the most frequent secondary condition in patients with spinal-cord injury (SCI); however, the actual incidence and prevalence are difficult to discern.1,2 A multicenter review of Model Spinal Cord Injury Systems data published in 1999 by McKinley et al 2 reported that 15.2% of persons with SCI had at least 1 PrU on the first annual follow-up evaluations after injury, with an incidence steadily increasing on subsequent evaluations. In 2005, Chen et al 3 corroborated these findings, reporting a PrU prevalence of 11.5% to 21% at 1- to 15-year follow-up from data contributed by 25 Model Spinal Cord Injury Systems, with increasing incidence with duration of SCI. Additionally, the reported lifetime occurrence of PrUs in SCI patients is 80% to 95%, with development of more than 1 PrU in 30% of patients.4 |   | Individuals with SCI develop PrUs from impaired mobility, loss of protective sensation, altered blood flow and autonomic function, moisture, and impaired nutrition, among other factors. These physiological changes also delay wound healing in this population. Treatment of PrUs is costly and time-consuming and can interfere with activities of daily living and thus independence, as well as vocational and leisure activities, resulting in diminished quality of life.1 A number of specialized dressings and adjuvant therapies have been developed to promote wound healing. Examples of widely used adjuvant therapies include hydrotherapy, electrical stimulation, ultrasound, infrared, ultraviolet, low-energy laser, hyperbaric oxygen therapy, and negative-pressure wound therapy (NPWT). |   | Potential benefits of NPWT include increased local blood flow and granulation, enhanced epithelial cell migration, decreased bioburden, removal of exudate and excess interstitial fluid, mechanical approximation of wound edges, and decreased shear forces and mechanical trauma to the wound, which can be exacerbated by frequent dressing changes.5 Use of NPWT for wound healing has been shown to be a safe and effective treatment for many types of lesions, including complex diabetic foot ulcers, postoperative sternal and abdominal wounds, and wartime missile injuries.5 A recent study in a mixed population treated by a home health group showed that NPWT decreased hospitalization rates for PrUs.6 However, the overall evidence to support the efficacy of NPWT in the treatment of chronic wounds remains weak and inconsistent.7 In specialized populations, such as those with SCI, even fewer studies exist to support (or contest) usage of NPWT.1 |   | The current recommendations for use of NPWT for chronic ulcers suggest its initiation in wounds with less than a 30% decrease in size after 2 to 4 weeks of appropriate treatment, or earlier in wounds with excessive exudate.8 Despite the lack of evidence for use of NPWT in persons with SCI, NPWT has been implemented frequently for chronic, nonhealing ulcers based on potential benefits and efficacy in the treatment of wounds in other patient populations. |   | The authors' study targeted pelvic (sacral, coccygeal, ischial, buttock) PrUs, the region in which most PrUs occur in patients with SCI. In an analysis of PrU occurrence in the SCI Model System database, 75% of the wounds in patients who developed PrUs within 2 years after acute injury were located in the pelvic region.9 A study by Carlson et al,10 involving 125 SCI subjects with PrUs assessed over multiple periods, determined that 81% of PrUs were located in the pelvic region, although the trochanteric region was included in their definition of the pelvic region. The purpose of this retrospective multicenter observational study was to establish the effectiveness of NPWT in the treatment of pelvic, Stage III/IV PrUs in patients with SCI. |   | Back to Top |   | METHODS |   | Back to Top |   | Study Design |   | Data were collected from the feasibility study for the Department of Veterans Affairs (VA) Cooperative Study (CS) Program, Study #535. This initiative was a prospective, observational study to determine feasibility for a large multicenter, randomized, placebo-controlled trial for the use of an anabolic agent for the treatment of nonhealing, full-thickness PrUs in patients with SCI. Fourteen SCI centers participated in the feasibility study for VA CS #535. All of these SCI centers are regional, tertiary referral centers that provide inpatient care for SCI veterans with Stage III/IV PrUs. The data utilized for this study were collected during the 28-day screening phase only; no experimental intervention or study medication was administered during this time. |   | During the 28-day screening phase, patients were provided with standard wound care according to the recommendations of the Consortium for Spinal Cord Medicine's Pressure Ulcer Prevention and Treatment Following Spinal Cord Injury: A Clinical Practice Guideline for Health-Care Professionals.1 Standard wound care of Stages III and IV PrUs included pressure relief (eg, low-air-loss mattress, turning, etc), debridement (eg, sharp, mechanical, enzymatic), routine dressing changes, biophysical modalities (eg, hydrotherapy), and cleansing as appropriate. The adjunctive therapy of NPWT was used at the discretion of the attending physicians as appropriate for each individual case and was prescribed for some of the study subjects at 10 of the 14 participating VA SCI centers. |   | Back to Top |   | Subjects and Wound Care |   | Data were collected from November 2003 to March 2005 on 86 hospitalized inpatients at the SCI centers associated with 10 VA Medical Facilities. Male or female inpatients (aged >=18 years) with SCI and at least 1 Stage III/IV (indicating a severe wound, <260 cm2) PrU of the pelvic region were eligible for the study. Exclusion criteria for the study are summarized in Table 1. | Table 1 | | | Implementation of all standard wound therapies and adjuvant therapies (including NPWT) was at the discretion of the attending physician. Standard wound care of Stages III and IV PrUs included pressure relief (eg, low-air-loss mattress, turning every 2 hours when in bed), debridement (eg, sharp, mechanical, enzymatic), dressing changes to ensure moist healing, biophysical modalities (eg, hydrotherapy), and cleansing with each dressing change and as required. These are consistent with the recommendations by the Consortium for Spinal Cord Medicine's Pressure Ulcer Prevention and Treatment Following Spinal Cord Injury: A Clinical Practice Guideline for Health-Care Professionals,1 which has been widely adopted as the standard of care for PrU clinical management following SCI in the United States. The most common therapies used for wound treatments when NPWT was not used were chemical debridement, antimicrobials, cleansing solutions, and combination therapies, and, to a lesser extent, wound fillers, contact layers, hydrogels/hydrocolloids, foams, alginates, and mechanical debridement. |   | Patients treated with standard wound care and NPWT (the NPWT group, n = 33) were retrospectively matched within each site for day 1 PrU wound surface area (WSA) and demographic variables with those who received standard wound care but did not receive the NPWT (the NoNPWT group, n = 53). To assess the effect of NPWT on PrU healing, the authors retrospectively compared wound healing outcomes of the NPWT group and the NoNPWT group. NPWT ranged from 1 to 4 weeks' duration during the 28-day screening phase. For the purpose of this report, PrUs were classified as healing if the WSA decreased (the healing subgroup) and as nonhealing if the WSA increased (the nonhealing subgroup) from day 1 to 28. A schematic of the groups and subgroups is provided (Figure 1). | Figure 1 | | | The study was approved by the local institution review board (IRB) at each of the participating sites and by the CS Program Coordinating Center IRB before initiation. Informed consent was obtained on all subjects. |   | Back to Top |   | Assessments |   | PrU dimensions and characteristics were collected by the study coordinator at each site using digital imaging technology and the Verg Videometer Measurement Documentation (VeV MD) software (Vista Medical, Winnipeg, Manitoba, Canada). The VeV MD system is a digital image analysis software program designed to calculate the maximum length, width, and total surface area of a wound via an image captured by a digital camera. Each digital image was calibrated using a square target plate included in the image and oriented in the same plane as the ulcer. The VeV MD system was chosen for its superiority to manual techniques for valid measurements of WSA, as well as for tracking and documentation purposes.11 The VeV MD system was used exclusively for measurement of the PrU WSA at each participating SCI center. To increase reliability and accuracy of interobserver wound measurements obtained using this software, the site coordinators were trained during the initial and subsequent annual meetings of VA CS #535 on the use of the VeV MD system, ensuring all researchers involved in wound measurements received the same training at the same time. Using the software, each site coordinator or investigator was able to create an outline of the wound margins on the digital image. This tracing was used to calculate the dimensions of the WSA in centimeters squared. If a patient had multiple pelvic Stage III or IV PrUs, a target PrU was identified as the largest WSA PrU for tracking during the 28-day study. |   | The PrU digital image and measurements were performed on day 1 (after debridement), during weeks 2 and 3, and on day 28 (±2 days). Only results from days 1 and 28 are reported herein. Percentage of change from day 1 to 28 was calculated as [(day 28 - day 1 / day 1) * 100], whereas a positive number represents an increase in WSA (nonhealing subgroup), and a negative number represents a decrease in WSA (healing subgroup). |   | A medical history, physical examination, and nutritional assessment (including weight) were performed on day 1. Laboratory data collected on days 1 and 28 (±2 days) included serum albumin,hemoglobin A1c, and liver function testing (total bilirubin, alkaline phosphatase, [gamma]-glutamyltransferase, alanine aminotransferase, and aspartate aminotransferase). |   | Back to Top |   | Statistical Analysis |   | Comparisons between the NoNPWT and NPWT groups for the continuous demographic variables were performed by unpaired t tests. Categorical or dichotomous variables were compared between the groups by chi-square analyses. Unpaired t tests were used for the continuous variables to compare the subgroups (healing PrU vs nonhealing PrU). Within the groups or subgroups, day 1 versus day 28 was compared by paired t tests. Percentage of change in PrU surface area from day 1 to 28 was calculated. Results are reported as a mean ± SD or as a percentage of occurrence. |   | Back to Top |   | RESULTS |   | During the 28-day period, 33 patients received NPWT, and 53 patients who did not receive NPWT were matched within each site. The NPWT group had a higher proportion of persons with complete motor and a lower proportion of complete sensory SCI lesions than the NoNPWT group. No other differences between the groups were found for any of the demographic variables (Table 2). | Table 2 | | | On average, patients in both groups had 3 to 4 total PrUs, 2 to 3 flap surgeries, and about 1 Stage III and 2 Stage IV PrUs since their SCI. No significant differences between the groups were noted for the PrU histories (Table 3). The groups did not differ statistically for the total current number of PrUs or distribution of the location of the wounds. Most PrUs were located on the ischium and sacrum (Table 4). For day 1, patients in the NPWT group compared with the NoNPWT group had larger PrUs (24 ± 28 vs 20 ± 15 cm2, not statistically significant [NS]) and were of shorter duration (20 ± 12 vs 33 ± 46 weeks, NS), although neither were statistically significant (Table 4). | Table 3 | Table 4 | | Overall from day 1 to 28, 59 of 86 patients had PrUs that were classified as healing and 27 as nonhealing. Comparisons between the NPWT (n = 33) and NoNPWT (n = 53) groups showed no significant differences in percentage of patients who demonstrated healing (70% vs 67%, NS) or nonhealing (30% vs 33%, NS). Patients were stratified within the NPWT as healing (n = 22) or nonhealing (n = 11) and NoNPWT as healing (n = 37) or nonhealing (n = 16). In patients who demonstrated healing PrUs, no significant difference was found between the NPWT versus NoNPWT for percentage of decrease in WSA (-43 ± 22% vs -50 ± 26%, respectively, NS). Similarly, in those with nonhealing PrUs, the percentage of increase in WSA was not statistically significant between the NPWT and NoNPWT groups (31 ± 26 vs 32 ± 34%, respectively, NS) (Figure 2). | Figure 2 | | | Serum albumin concentrations were significantly improved in the healing groups from days 1 to 28 (Figure 3). At day 28, in the NPWT group, the subgroup with nonhealing PrUs (11/33) had significantly lower serum albumin levels than the subgroup with PrU healing (22/33) (2.90 ± 0.4 vs 3.3 ± 0.5 mg/dL, P < .05). In contrast, there was no significant difference in serum albumin levels in the NoNPWT group, regardless of healing status (3.19 ± 0.32 vs 3.23 ± 0.25 mg/dL, NS) (Figure 3). A higher percentage of patients in the NPWT compared with NoNPWT group had a day 28 serum albumin concentration of less than 3.0 mg/dL (41% vs 26%, P = .16). There were no significant differences between the NPWT and NoNPWT groups, or the healing compared with the nonhealing subgroups for hemoglobin A1c or the transaminases or bilirubin. | Figure 3 | | | Back to Top |   | DISCUSSION |   | In this retrospective analysis, the authors found no significant difference in the healing outcomes of chronic Stage III or IV pelvic PrUs in patients with SCI in those treated with standard of care with NPWT or without NPWT over the course of a 4-week observational period. The percentages of PrUs classified as healing or nonhealing were similar in both groups, as well as the average percentage of change in WSA for those who did or did not demonstrate healing. The only significant difference between the subgroups was the finding of a lower level of serum albumin concentration in those who received NPWT and whose wounds worsened over the 28-day period, suggesting malnutrition in this group and lack of efficacy of NPWT to improve wound closure if nutritional status is poor. Interestingly, this was not true in the NoNPWT group, with no significant difference found in the albumin concentrations of patients who demonstrated healing versus those with nonhealing PrUs. These findings possibly suggest that application of the NPWT may have partially contributed to the lower (or in maintaining the lower) serum albumin concentrations in persons who have malnutrition and a reduced ability to compensate for the wound-related protein loss. |   | Nutrition has been shown to play a role in wound prevention and thought to play a role in wound healing, although more research on the effects of nutrition on wounds is needed.12,13 Based on the authors' results discussed in this article, nutrition appears to play a significant role in the PrU healing outcomes of SCI patients treated with NPWT. |   | Patients in the NoNPWT group were retrospectively matched with the subjects in the NPWT group. Comparative analysis of demographics, medical history, and PrU characteristics revealed that the only significant difference between the 2 treatment groups (NPWT vs NoNPWT) was a higher percentage of patients with complete (vs incomplete) SCI in the NPWT group. Whether the presence of sensation or some level of sensory innervations could have influenced our findings is not known, although completeness of injury is known to be a risk factor for developing PrUs.1 |   | Evidence for the use of NPWT for chronic PrUs is inconsistent and ambiguous. Some current wound management guidelines recommend the use of NPWT in chronic, nonhealing Stages III and IV PrUs, but publications specifically considering the SCI population refrain from endorsing the use of NPWT for the treatment of PrUs in SCI patients, citing insufficient evidence to support its use. Denervated tissue has altered collagen metabolism and composition, resulting in decreased tensile strength and increased fragility, and SCI patients also have multiple risk factors for PrU formation and management, including incontinence, immobility, and sensory impairment.1 Therefore, they might need to be considered separately from other patient populations. As published in the Pressure Ulcer Prevention and Treatment Clinical Practice Guidelines in 2000, the Consortium for Spinal Cord Medicine recognizes the lack of evidence on the use of NPWT in the SCI population and comments that "the efficacy of negative pressure for promoting closure of Stages III and IV PrUs has not been sufficiently established to permit recommendation of this intervention for SCI individuals."1 In contrast, for the mixed PrU population, the Wound Healing Society's 2006 Guidelines for the Treatment of Pressure Ulcers reported level I evidence to support consideration of NPWT for Stage III or IV PrUs that "fail to progress with conventional therapy."13 In 2003, a Canadian Consensus Group set forth recommendations on how to administer NPWT and implement treatment modifications, but they could not advocate its use in chronic wounds until more information was available.8 The 2005 "Guidelines for Pressure Ulcer Prevention and Care" published in another wound care publication did not contain any guidelines on the use of NPWT secondary to lack of existing evidence to support its use.14 |   | More recently, the 2008 Cochrane Review, "Topical Negative Pressure for Treating Chronic Wounds," also reported in the general PrU population "little high-level evidence to support the use of topical negative pressure (TNP) in the treatment of chronic wounds. More rigorous evaluation is essential before the use of TNP can become routine and reimbursed for local wound care in clinical and outpatient care settings."15 The authors' study results provide further support that there is no clear evidence for the use of NPWT on SCI patients with PrUs. |   | Although there are few published reports or data on the potential adverse effects of treatment with NPWT, it is known clinically that it may cause complications. Potential complications include necrosis of skin under the evacuation tubing (especially over bony prominences or in ischemic wounds), adherence of the dressing to wound bed, or growth of granulation tissue into the sponge, resulting in minor bleeding or possible discomfort inpatients with incomplete injury and bruising with anticoagulation.16 Contraindications to NPWT include incomplete debridement of necrotic tissue, exposed blood vessels or organs within the wound, malignancy within the wound, unresolved osteomyelitis, and open fistulas to body cavities. Other contraindications include inability of the patient or caregiver to understand the treatment or adhere to the protocol. Furthermore, the cost of NPWT is often prohibitive in the outpatient setting.15 A study by Luckraz et al 17 calculated that the total cost for NPWT (hospitalization and treatment) per patient with wound infections after cardiac surgery was $16,400. Another study by Philbeck et al 18 estimated that the cost of healing chronic wounds at home with NPWT was about $14,546. Supporters of NPWT admit that the daily costs of this modality are high, but they claim that with faster healing rates, the total expense using NPWT is less than standard therapy.5,6,18 NPWT lacks definite evidence on its use in patients with SCI and chronic full-thickness PrUs. The authors' study provides some much-needed evidence for the limitations of NPWT in patients with SCI with PrUs who have low albumin levels. |   | Back to Top |   | STUDY STRENGTHS |   | This study is the largest multicenter trial on SCI PrU treatment to date, using the collaboration of 10 VA SCI centers across the United States. Also, this is the first study in patients with SCI to compare the addition of NPWT to the recommended standards of wound care. All of the authors' subjects received optimized care-they were hospitalized for the duration of the study period and thus in a controlled environment with reliably administered wound care, pressure relief, and nutritional intervention. The PrUs were frequently assessed by wound care specialists. In addition, all patients were treated by an interdisciplinary team, including physicians, nurses, physical and occupational therapists, psychologists, social workers, and dietitians. Such an integrated, coordinated approach eliminated or controlled many confounding variables that could have affected wound healing and the outcome of the study. The level of care rendered would have been impossible to accomplish in an outpatient setting. Because admission and continued hospitalization for wound care alone are not covered by many private third-party health insurers, non-VA hospital systems generally are not capable of admitting patients for care of advanced PrUs. Arguably, this study could not have been accomplished in a non-VA institution. |   | Another strength of this study lies in the objective measurements of wound area provided by the VeV MD software, which has been shown to be more reliable than manual measurements.11 This reliability was bolstered by standardization of the VeV MD system use by requiring all site coordinators to attend a training course on application of this software and acquiring of the digital images, ensuring that the measurements with the VeV MD system were performed by equally skilled personnel across the sites. |   | The authors note that there was no corporate bias for this study, nor were there any sources of commercial funding or support. None of the authors were affiliated with the companies or with their competitors of the products used during this study. |   | Back to Top |   | STUDY LIMITATIONS |   | The first of the 2 most prominent limitations of the authors' study was the lack of depth measurements or consideration of improvement in undermining or tunneling in the authors' analysis. In a case series of non-SCI subjects, NPWT has been shown to significantly decrease depth in large PrUs, with a greater effect on depth than on surface area.19 Joseph et al 20 reported a significant decrease in wound depth with NPWT compared with moist saline dressings. Although manual wound depths were assessed and recorded, they were not included in the authors' analyses or outcome measures. Only WSA, as measured by the VeV MD software, was analyzed and used for the authors' classification of healing or nonhealing wounds. Thus, if NPWT made significant changes in wound depth, it would have been missed in the authors' assessment. |   | The second notable weakness of the authors' study was the lack of obtaining prealbumin levels, which were not systematically collected during the feasibility study screening phase and not available for analyses. Prealbumin is a better indicator of recent nutrition than albumin, as it is influenced by fewer metabolic processes, including dehydration.21 Prealbumin levels would have been helpful in the nutritional assessment of our patients, particularly because a significantly lower albumin concentration was found in the healing subgroup versus nonhealing subgroup in the NPWT group, a finding that would have been strengthened as an indicator of malnutrition by low prealbumin levels as well. |   | Because this phase of the CS #535 was not a randomized controlled trial (RCT), many variables that could have easily been assessed and controlled for the purposes of the study herein were not, and data that would have been collected in the setting of an RCT were not available in the authors' retrospective analysis. For example, weekly weights and more reliable laboratory assessments of nutrition (rather than albumin alone) would have been helpful for determining nutritional status. Too low prealbumin, hemoglobin, and hematocrit levels were drawn to include in the statistical analysis, although these laboratory tests have been recommended in the initial assessment of all patients with PrUs.1 Also, more accurate records of the treatments administered, including the NPWT settings, would have been documented in an RCT. |   | Unfortunately, the system settings used in the NPWT group were not available for the authors' analysis, so it was not possible to compare the outcomes of those who received pulsed/intermittent versus continuous suction. In addition, the pressure settings were not recorded, nor were the frequencies of dressing changes. The duration of wound observation to assess the effectiveness of NPWT in the authors' patients was not known, but a period longer than 28 days would have been preferable. Ideally, patients would have been followed up to wound closure to permit analysis to determine if the use of NPWT had an effect on later wound outcomes. |   | Back to Top |   | FUTURE RESEARCH |   | More research on the effects of NPWT for wound healing is needed in chronic PrUs in general, and in the SCI population specifically, before recommendations can be made on its use. Future studies should include more adequate markers of nutritional status (including serum prealbumin concentrations) and the ability to follow up subjects over more extended periods than 4 weeks and, ideally, to wound closure. |   | Back to Top |   | CONCLUSION |   | Treatment with NPWT did not significantly influence the rate of Stage III or IV pelvic PrU healing in subjects with SCI. Nutritional status appears to play a key role in the effectiveness of NPWT in the treatment of Stages III and IV pelvic PrUs in the SCI population. |   | Back to Top |   | Acknowledgments: |   | Funding for this study was provided by the Department of Veterans Affairs, VA Office of Research and Development, Clinical Sciences Service, Cooperative Studies Program, CS #535; SCI Service and Rehabilitation Research and Development Center of Excellence for the Medical Consequences of SCI #B4162C, James J. Peters VA Medical Center, Bronx, New York. The authors acknowledge Dr William Krol, as well as the following participating sites and site investigators for their effort and participation in this project: Charlie Norwood VA Medical Center (Augusta, Georgia)-Rose C. Trincher, MD; James J. Peters VA Medical Center (Bronx, New York)-George A. Deitrick, MD; Louis Stokes VA Medical Center (Cleveland, Ohio)-Chester H. Ho, MD; VA North Texas Healthcare System: Dallas VA Medical Center-Lance L. Goetz, MD; Edward Hines Jr VA Hospital (Hines, Illinois)-Bernard A. Nemchausky, MD; Michael E. Debakey VA Medical Center (Houston, Texas)-Sally A. Holmes, MD; VA Palo Alto Health Care System (Palo Alto, California)-Roy Sasaki, MD; Hunter Holmes McGuire VA Medical Center (Richmond, Virginia)-Meena Midha, MD; James A. Haley Veterans' Hospital (Tampa, Florida)-John L. Merritt, MD; and VA Boston Healthcare System, West Roxbury Campus (Boston, Massachusetts)-Sunil Sabharwal, MD. |   | Back to Top |   | REFERENCES |   | 1. Consortium for Spinal Cord Medicine. Paralyzed Veterans of America. Pressure ulcer prevention and treatment following spinal cord injury: a clinical practice guideline for health-care professionals. Washington, DC: Paralyzed Veterans of America; 2000. [Context Link] |   | 2. McKinley WO, Jackson AB, Cardenas DD, DeVivo MJ. Long-term medical complications after traumatic spinal cord injury: a regional model systems analysis. Arch Phys Med Rehabil 1999;80(11):1402-10. 360 Link esolver [Context Link] |   | 3. Chen Y, Devivo MJ, Jackson AB. Pressure ulcer prevalence in people with spinal cord injury: age-period-duration effects. Arch Phys Med Rehabil 2005;86(6):1208-13. 360 Link esolver [Context Link] |   | 4. Lindsey L, Klebine P, Oberheu AM. Prevention of pressure sores through skin care. In: Jackson AB, Mott P, eds. Spinal Cord Injury InfoSheets. Birmingham, AL: Spinal Cord Injury Information Network; 2000. InfoSheet #13. [Context Link] |   | 5. Gasbarro R. Negative pressure wound therapy: a clinical review. Wounds 2007;19(Suppl 12):2-7. 360 Link esolver [Context Link] |   | 6. Schwien T, Gilbert J, Lang C. Pressure ulcer prevalence and the role of negative pressure wound therapy in home health quality outcomes. Ostomy Wound Manage 2005;51(9):47-60. 360 Link esolver [Context Link] |   | 7. Gregor S, Maegele M, Sauerland S, Krahn JF, Peinemann F, Lange S. Negative pressure wound therapy: a vacuum of evidence' Arch Surg 2008;143(2):189-96. 360 Link esolver [Context Link] |   | 8. Sibbald RG, Mahoney J; V.A.C. Therapy Canadian Consensus Group. A consensus report on the use of vacuum-assisted closure in chronic, difficult-to-heal wounds. Ostomy Wound Manage 2003;49(11):52-66. 360 Link esolver [Context Link] |   | 9. Yarkony GM. Pressure ulcers. In: Stover SL, Delisa JA, Whiteneck GG, eds. Spinal Cord Injury: Clinical Outcomes from the Model Systems. Gaithersburg, MD: Aspen; 1995:100-19. [Context Link] |   | 10. Carlson CE, King RB, Kirk PM. Incidence and correlates of pressure ulcer development after spinal cord injury. J Rehabil Nurs Res 1992;1:34-40. [Context Link] |   | 11. Haghpanah S, Bogie K, Wang X, Banks PG, Ho CH. Reliability of electronic versus manual wound measurement techniques. Arch Phys Med Rehabil 2006;87(10):1396-402. 360 Link esolver [Context Link] |   | 12. Langer G, Schloemer GJ, Knerr A, Kuss O, Behrens J. Nutritional interventions for preventing and treating pressure ulcers. Cochrane Database Syst Rev 2003(4):CD003216. [Context Link] |   | 13. Whitney J, Phillips L, Aslam R, et al. Guidelines for the treatment of pressure ulcers. Wound Repair Regen 2006;14:663-79. 360 Link esolver Buy Now [Context Link] |   | 14. van Rijswijk L, Lyder CH. Pressure ulcer prevention and care: implementing the revised guidance to surveyors for long-term care facilities. Ostomy Wound Manage 2005;Suppl:7-19. [Context Link] |   | 15. Ubbink DT, Westerbos SJ, Evans D, Land L, Vermeulen H. Topical negative pressure for treating chronic wounds. Cochrane Database Syst Rev 2008;16(3):CD001898. 360 Link esolver [Context Link] |   | 16. Hess CL, Howard MA, Attinger CE. A review of mechanical adjuncts in wound healing: hydrotherapy, ultrasound, negative pressure therapy, hyperbaric oxygen, and electrostimulation. Ann Plast Surg 2003;51:210-8. 360 Link esolver Request Permissions Buy Now [Context Link] |   | 17. Luckraz H, Murphy F, Bryant S, Charman SC, Ritchie AJ. Vacuum-assisted closure as a treatment modality for infections after cardiac surgery. J Thorac Cardiovasc Surg 2003;125:301-5. 360 Link esolver [Context Link] |   | 18. Philbeck TE Jr, Whittington KT, Millsap MH, Briones RB, Wight DG, Schroeder WJ. The clinical and cost effectiveness of externally applied negative pressure wound therapy in the treatment of wounds in home healthcare Medicare patients. Ostomy Wound Manage 1999;45(11):41-50. 360 Link esolver [Context Link] |   | 19. Kennedy A, Van Zant RS. Diverse applications of negative pressure wound therapy: a multiple case report. Physiother Theory Pract 2006;22(2):83-90. 360 Link esolver [Context Link] |   | 20. Joseph E, Hamori C, Bergman S, Roaf E, Swann NF, Anastasi G. A prospective randomized trial of vacuum assisted closure versus standard therapy of therapy of chronic non-healing wounds. Wounds 2000;12(3):60-7. 360 Link esolver [Context Link] |   | 21. Dempsey DT, Mullen JL, Buzby GP. The link between nutritional status and clinical outcome: can nutritional intervention modify it' Am J Clin Nutr 1988;47(Suppl 2):352-6. 360 Link esolver [Context Link] |   | |   | IMAGE GALLERYSelect All Table 1 | Figure 1 | Table 2 | Table 3 | Table 4 | Figure 2 | Figure 3 |   | | |