The Use of Silver Oxynitrate Wound Dressings in the Treatment of Chronic Wounds: A Feasibility Pilot Study

OBJECTIVE

To evaluate the feasibility and effectiveness of a silver oxynitrate (Ag 7 NO 11 ) dressing on wound healing in patients with stalled chronic wounds.

METHODS

A prospective pilot study was conducted to determine the feasibility and effect of using silver oxynitrate dressings within an outpatient setting in Alberta, Canada. A total of 23 patients (12 women and 11 men; mean age, 66.1 ± 13.8 years) with a chronic wound that failed to heal with conventional treatment were included in the study. Wound assessments including the Bates-Jensen Wound Assessment Tool, wound-related pain, wound size, and patient quality of life (QoL) were conducted at baseline, after dressing application for 1 and 2 weeks, and during 4- and 12-week follow-ups.

RESULTS

Dressing application at 1 and 2 weeks improved patients' wound healing progression as measured through significantly decreased Bates-Jensen Wound Assessment Tool scores with a more than 10% decrease at 4- and 12-week follow-up ( P < .001). Pain ( P = .004), and QoL psyche subscore ( P = .008) significantly improved at 4-week follow-ups, although wound area, perimeter, and QoL body and everyday subscores were not significantly affected. Wound size was not significantly affected.

CONCLUSIONS

The silver oxynitrate dressing may improve healing progression in patients with chronic wounds, enhance patient experience by reducing wound-related pain, and improve patients' mental well-being. Further studies are warranted to elucidate the effect of silver oxynitrate dressings on wound area, perimeter, and volume measurements.

A Scoping Review of the Use of Silver-impregnated Dressings for the Treatment of Chronic Wounds

Topical silver agents and dressings are used to control infection and promote healing in chronic wounds, but reviews published from 2006 to 2011 found heterogeneous results regarding their effectiveness. A scoping review was conducted to examine the extent, range, and nature of research activity surrounding chronic wound care that employed silver-impregnated dressings; identify research gaps in the existing literature; and summarize the evidence to provide recommendations for future clinical studies. Ten (10) electronic databases and additional sources were screened from their inception to May 2016; search terms for the different databases included but were not limited to silver, chronic, complications, wound, ulcer, and sore. English-language articles that compared silver dressings with an alternate treatment in adults with chronic wounds and that reported clinical outcome measures were included. Of 222 full-text reviewed studies, 27 were included for qualitative analysis. Qualitative analysis was guided by key findings identified among the included studies that were analyzed in aggregate form where appropriate. In comparative analyses of the 26 studies that investigated wound healing, 15 revealed significantly positive wound healing outcomes with silver treatments versus 9 that did not; the remaining 2 failed to provide statistical values of significance. Of 17 studies that presented data on microbiology, 3 reported significant microbial load improvement for silver dressings, 9 noted nonsignificant findings, and 4 provided no statistical values. Pain, adverse events, and treatment cost were included in 5, 7, and 3 studies, respectively, with heterogeneous findings. The heterogeneous evidence regarding the impact of silver dressings on clinical outcomes may be related to differences in the silver treatments themselves, heterogeneous intervention strategies, study designs, outcomes, and measures. Well-designed clinical studies with multiple outcome parameters are necessary to determine the optimal type and use of silver-dressings in chronic wounds.

The Effect of Whole-body Vibration on Muscle Activity in Active and Inactive Subjects

The purpose of this study was to compare lower limb muscle activity between physically active and inactive individuals during whole-body vibration exercises. Additionally, transmissibility of the vertical acceleration to the head was quantified. 30 active and 28 inactive participants volunteered to stand in a relaxed (20°) and a squat (60°) position on a side-alternating WBV platform that induced vibrations at 16 Hz and 4 mm amplitude. Surface electromyography (sEMG) was measured in selected lower limb muscles and was normalized to the corresponding sEMG recorded during a maximal voluntary contraction. The vertical acceleration on the head was evaluated and divided by the vertical platform acceleration to obtain transmissibility values. Control trials without vibration were also assessed. The outcomes of this study showed that (1) WBV significantly increased muscle activity in the active (absolute increase: +7%, P <0.05) and inactive participants (+8%, P <0.05), (2) with no differences in sEMG increases between the groups (P>0.05). However, (3), transmissibility to the head was greater in the active (0.080) than the inactive participants (0.065, P <0.05). In conclusion, inactive individuals show similar responses in sEMG due to WBV as their active counterparts, but are at lower risk for potential side-effects of vibration exposure.

sEMG during Whole-Body Vibration Contains Motion Artifacts and Reflex Activity

The purpose of this study was to determine whether the excessive spikes observed in the surface electromyography (sEMG) spectrum recorded during whole-body vibration (WBV) exercises contain motion artifacts and/or reflex activity. The occurrence of motion artifacts was tested by electrical recordings of the patella. The involvement of reflex activity was investigated by analyzing the magnitude of the isolated spikes during changes in voluntary background muscle activity. Eighteen physically active volunteers performed static squats while the sEMG was measured of five lower limb muscles during vertical WBV using no load and an additional load of 33 kg. In order to record motion artifacts during WBV, a pair of electrodes was positioned on the patella with several layers of tape between skin and electrodes. Spectral analysis of the patella signal revealed recordings of motion artifacts as high peaks at the vibration frequency (fundamental) and marginal peaks at the multiple harmonics were observed. For the sEMG recordings, the root mean square of the spikes increased with increasing additional loads (p < 0.05), and was significantly correlated to the sEMG signal without the spikes of the respective muscle (r range: 0.54 - 0.92, p < 0.05). This finding indicates that reflex activity might be contained in the isolated spikes, as identical behavior has been found for stretch reflex responses evoked during direct vibration. In conclusion, the spikes visible in the sEMG spectrum during WBV exercises contain motion artifacts and possibly reflex activity. Key pointsThe spikes observed in the sEMG spectrum during WBV exercises contain motion artifacts and possibly reflex activityThe motion artifacts are more pronounced in the first spike than the following spikes in the sEMG spectrumReflex activity during WBV exercises is enhanced with an additional load of approximately 50% of the body mass.

Validity and reliability of isometric, isokinetic and isoinertial modalities for the assessment of quadriceps muscle strength in patients with total knee arthroplasty

Reliability of isometric, isokinetic and isoinertial modalities for quadriceps strength evaluation, and the relation between quadriceps strength and physical function was investigated in 29 total knee arthroplasty (TKA) patients, with an average age of 63 years. Isometric maximal voluntary contraction torque, isokinetic peak torque, and isoinertial one-repetition maximum load of the involved and uninvolved quadriceps were evaluated as well as objective (walking parameters) and subjective physical function (WOMAC). Reliability was good and comparable for the isometric, isokinetic, and isoinertial strength outcomes on both sides (intraclass correlation coefficient range: 0.947-0.966; standard error of measurement range: 5.1-9.3%). Involved quadriceps strength was significantly correlated to walking speed (r range: 0.641-0.710), step length (r range: 0.685-0.820) and WOMAC function (r range: 0.575-0.663), independent from the modality (P < 0.05). Uninvolved quadriceps strength was also significantly correlated to walking speed (r range: 0.413-0.539), step length (r range: 0.514-0.608) and WOMAC function (r range: 0.374-0.554) (P < 0.05), except for WOMAC function/isokinetic peak torque (P > 0.05). In conclusion, isometric, isokinetic, and isoinertial modalities ensure valid and reliable assessment of quadriceps muscle strength in TKA patients.

Validity of the Optogait photoelectric system for the assessment of spatiotemporal gait parameters

The purpose of this study was to evaluate the discriminant and concurrent (criterion-related) validity of a recently introduced floor-based photocell system (Optogait, Microgate, Bolzano, Italy) with a validated electronic walkway for the assessment of spatiotemporal gait parameters. Fifteen patients (mean age±standard deviation: 65±7 years) with total knee arthroplasty and 15 healthy matched control subjects were asked to walk at different velocities while gait variables were recorded simultaneously by the two instruments. The Optogait and the criterion instrument detected the same differences in walking parameters between patients and controls. Intraclass correlation coefficients ranged between 0.933 (swing time) and 0.999 (cycle time, cadence and walking speed). Cycle time and stance time were significantly longer, while swing time, step length, cadence and walking speed were significantly lower for Optogait (p<0.001) compared to the criterion instrument. The Optogait system demonstrated high discriminant and concurrent validity with an electronic walkway for the assessment of spatiotemporal gait parameters in orthopedic patients and healthy controls. However, the two measuring instruments cannot be used interchangeably for quantitative gait analysis, and further validation of floor-based photocell technology is warranted.