Rita A. Frantz

The validity of the clinical signs and symptoms used to identify localized chronic wound infection

It is uncertain how accurately classic signs of acute infection identify infection in chronic wounds, or if the signs of infection specific to secondary wounds are better indicators of infection in these wounds. The purpose of this study was to examine the validity of the “classic” signs (i.e., pain, erythema, edema, heat, and purulence) and the signs specific to secondary wounds (i.e., serous exudate, delayed healing, discoloration of granulation tissue, friable granulation tissue, pocketing at the base of the wound, foul odor, and wound breakdown). Thirty‐six chronic wounds were assessed for these signs and symptoms of infection with interobserver reliability ranging from 0.53 to 1.00. The wounds were then quantitatively cultured, and 11 (31%) were found to be infected. Increasing pain, friable granulation tissue, foul odor, and wound breakdown showed validity based on sensitivity, specificity, discriminatory power, and positive predictive values. The signs specific to secondary wounds were better indicators of chronic wound infection than the classic signs with a mean sensitivity of 0.62 and 0.38, respectively. None of the signs or symptoms was a necessary indicator of infection, but increasing pain and wound breakdown were both sufficient indicators with specificity of 100%.

Effect of electrical stimulation on chronic wound healing: a meta-analysis

The purpose of this meta‐analysis was to quantify the effect of electrical stimulation on chronic wound healing. Fifteen studies, which included 24 electrical stimulation samples and 15 control samples, were analyzed. The average rate of healing per week was calculated for the electrical stimulation and control samples. Ninety‐five percentage confidence intervals were also calculated. The samples were then grouped by type of electrical stimulation device and chronic wound and reanalyzed. Rate of healing per week was 22% for electrical stimulation samples and 9% for control samples. The net effect of electrical stimulation was 13% per week, an increase of 144% over the control rate. The 95% confidence intervals of the electrical stimulation (18–26%) and control samples (3.8–14%) did not overlap. Electrical stimulation was most effective on pressure ulcers (net effect = 13%). Findings regarding the relative effectiveness of different types of electrical stimulation device were inconclusive. Although electrical stimulation produces a substantial improvement in the healing of chronic wounds, further research is needed to identify which electrical stimulation devices are most effective and which wounds respond best to this treatment.

Effectiveness of transcutaneous electrical nerve stimulation on postoperative pain with movement

This study tested the effectiveness of episodic transcutaneous electrical nerve stimulation (TENS) as a supplement to pharmacologic analgesia on pain with movement and at rest after abdominal surgery and evaluated whether its use during walking and vital capacity maneuvers enhances performance of these activities. TENS, with a modulated frequency, intensity as high as the subject could tolerate, and electrodes placed on either side and parallel to the incision, was compared to placebo TENS and pharmacologic analgesia alone (control) by using a crossover design. Self-report of pain intensity, walking function, and vital capacity were assessed on 33 subjects. TENS resulted in significantly less pain than the control during both walking (P <.5) and vital capacity activities (P <.1) and significantly less pain than placebo TENS during vital capacity (P <.01). TENS also produced significantly better gait speeds than the control (P <.05) and greater gait distances (P <.01) than the control and placebo TENS. Vital capacity and pain intensity at rest were not significantly different among the 3 treatments. These results suggest TENS reduces pain intensity during walking and deep breathing and increases walking function postoperatively when used as a supplement to pharmacologic analgesia. The lack of effect on pain at rest supports the hypothesis that TENS works through reducing hyperalgesia.

Diagnostic validity of three swab techniques for identifying chronic wound infection

This study examined the diagnostic validity of three different swab techniques in identifying chronic wound infection. Concurrent swab specimens of chronic wounds were obtained using wound exudate, the Z‐technique, and the Levine technique, along with a specimen of viable wound tissue. Swab and tissue specimens were cultured using quantitative and qualitative laboratory procedures. Infected wounds were defined as those containing 1 × 106 or more organisms per gram of tissue. Accuracy was determined by associating the quantitative cultures of swab specimens with the cultures from tissue specimens using receiver operating characteristic curves. Of the 83 study wounds, 30 (36%) were infected. Accuracy was the highest for swab specimens obtained using Levines technique at 0.80. Based on Levines technique, a critical threshold of 37,000 organisms per swab provided a sensitivity of 90% and a specificity of 57%. The mean concordance between swab specimens obtained using Levines technique and tissue specimens was 78%. The findings suggest that swab specimens collected using Levines technique provide a reasonably accurate measure of wound bioburden, given that they are more widely applicable than tissue cultures. The diagnostic validity of Levines technique needs further study using an alternative reference standard, such as the development of infection‐related complications.

Wound Bioburden and Infection-Related Complications in Diabetic Foot Ulcers

The identification and diagnosis of diabetic foot ulcer (DFU) infections remains a complex problem. Because inflammatory responses to microbial invasion may be diminished in persons with diabetes, clinical signs of infection are often absent in persons with DFUs when infection is limited to localized tissue. In the absence of these clinical signs, microbial load is believed to be the best indicator of infection. Some researchers, however, believe microbial load to be insignificant and type of organism growing in the ulcer to be most important. Previous studies on the microbiology of DFUs have not provided enough evidence to determine the microbiological parameters of importance. Infection-related complications of DFUs include wound deterioration, osteomyelitis, and amputation. Risk factors for amputation include age, peripheral vascular disease, low transcutaneous oxygen, smoking, and poor glycemic control. These risk factors are best measured directly with physiological measures of arterial perfusion, glycemic control, sensory neuropathy, plantar pressures, and activity level and by controlling off-loading. DFU bioburden has not been examined as a risk factor for infection-related complications. To address the relationship between wound bioburden and the development of infection-related complications in DFUs, tightly controlled prospective studies based on clearly defined, valid measures of wound bioburden and wound outcomes are needed. This article reviews the literature and proposes a model of hypothesized relationships between wound bioburden—including microbial load, microbial diversity, and pathogenicity of organisms—and the development of infection-related complications.

Clinical signs of infection in diabetic foot ulcers with high microbial load.

Aims. One proposed method to diagnose diabetic foot ulcers (DFUs) for infection is clinical examination. Twelve different signs of infection have been reported. The purpose of this study was to examine diagnostic validity of each individual clinical sign, a combination of signs recommended by the Infectious Disease Society of America (IDSA), and a composite predictor based on all signs of localized wound infection in identifying DFU infection, among a sample of DFUs. Methods. A cross-sectional research design was used. Sixty-four individuals with DFUs were recruited from a Department of Veterans Affairs Medical Center and an academic-affiliated hospital. Each DFU was independently assessed by 2 research team members using the clinical signs and symptoms checklist. Tissue specimens were then obtained via wound biopsy and quantitatively processed. Ulcers with more than 106 organisms per gram of tissue were defined as having high microbial load. Individual signs and the IDSA combination were assessed for validity by calculating sensitivity, specificity, and concordance probability. The composite predictor was analyzed using c-index and receiver operating curves. Results. Twenty-five (39%) of the DFUs had high microbial loads. No individual sign was a significant predictor of high microbial load. The IDSA combination was not a significant predictor either. The c-index of the composite predictor was .645 with a 95% confidence interval of .559-.732. Conclusions. Individual signs of infection do not perform well nor does the IDSA combination of signs. However, a composite predictor based on all signs provides a moderate level of discrimination, suggesting clinical use. Larger sample sizes and alternate reference standards are recommended.

A Comparison of Patient Risk for Pressure Ulcer Development with Nursing Use of Preventive Interventions

Objective: (1) Determine if the Braden scale or Norton scale predicted the same patients to be at risk for pressure ulcer development as were receiving preventive nursing interventions. (2) Identify the items on the Braden and Norton risk assessment scales that the nurses used intuitively to determine a patients need for a preventive intervention.

Translating pressure ulcer guidelines into practice: it's harder than it sounds.

OBJECTIVE To determine the cost-effectiveness of a guideline-based pressure ulcer prevention protocol over time. DESIGN Retrospective and prospective quasi-experimental longitudinal design. Costs are presented from the long-term-care facility perspective. Data collection occurred for 3 periods: the first 6 months of 1994 (prior to protocol implementation), the first 6 months of 1995 (immediately following implementation) and the first 6 months of 1997 (2 years following implementation). SETTING 77-bed long-term-care facility PATIENTS/PARTICIPANTS Subjects were ulcer-free facility residents at the start of each data collection period. There were 69 subjects in the 1994 sample, 63 in the 1995 sample, and 71 in the 1997 sample. INTERVENTIONS A guideline-based pressure ulcer prevention protocol was implemented during the last 3 months of 1994. The protocol consisted of specific policies for pressure ulcer prevention and treatment, intensive staff education on pressure ulcer care, and monitoring with regular performance feedback to staff. MEASUREMENTS AND MAIN RESULTS Time to ulcer development varied among the 3 groups (log rank = 8.81, P = .01), with longer time to ulcer development in 1995 compared with 1994; no difference was seen between 1997 and 1994. The time for ulcers to heal decreased over the 3 years (log rank = 9.49, P <.01), with ulcer healing time being shorter in 1995 and 1997 compared with 1994. Total costs were unchanged during the 3 years (F = 0.2, P =.81). Costs of treatment declined significantly from 1994 to 1995 and 1997 (F = 5.5, P <.01) and costs of prevention increased significantly from 1994 to 1995 and 1997(F = 15, P <.01). From 1994 to 1997, the cost for 1 day of ulcer-free life was

4.5-Gram Monofilament Sensation Beneath Both First Metatarsal Heads Indicates Protective Foot Sensation in Diabetic Patients

3.50. CONCLUSIONS Implementation of a pressure ulcer prevention protocol showed mixed results. Initial reductions in pressure ulcer incidence were lost over time. Clinical results of ulcer treatment, however, improved and treatment costs fell during the 3 years. Implementation of preventive programs poses a major leadership challenge.

Nursing assessment: Impact on type and cost of interventions to prevent pressure ulcers

BACKGROUND Loss of protective plantar foot sensation is the major cause of diabetic foot ulcerations and ultimate limb loss. Identification of patients without protective sensation can reduce the risk of unrecognized foot injury. The current recommended screening protocol requires 10-g monofilament testing of ten foot sites with use of a forced-choice paradigm. The objective of the present study was to determine whether testing of fewer than ten sites could provide accuracy comparable with that obtained by testing all ten sites. METHODS A cross-sectional comparative study of plantar sensory levels in diabetic subjects with and without plantar ulceration was conducted in a tertiary-care teaching hospital setting. We examined forty-seven diabetic subjects with a history of foot ulceration and forty-five diabetic subjects with no history of foot ulceration. Plantar sensory threshold values at five sites on the sole of each foot were measured with a quasi-continuous range of applied forces, and receiver operating characteristic analysis techniques were applied. RESULTS Screening on the basis of only the maximum force threshold for the left and right first metatarsal head sites provided comparable or better performance at high levels of sensitivity than did either the mean or the maximum force threshold across all ten sites. A sensory threshold of 4.5 g for both the left and right first metatarsal head sites predicted the risk of ulceration with a sensitivity of 100% and a specificity of 67%. CONCLUSIONS Testing of diabetic patients for protective sensation may be simplified to testing under both first metatarsal heads with a 4.5-g monofilament. If a patient cannot sense the application of a 4.5-g monofilament under either first metatarsal head, he or she probably has lost protective sensation and should be considered to be at risk for undetected injury.