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 Table of Contents  
ORIGINAL ARTICLE
Year : 2018  |  Volume : 31  |  Issue : 2  |  Page : 462-466

Effect of ultrasound-assisted debridement on wound healing and infection outcomes in diabetic foot


1 Internal Medicine Department, Mansoura General Hospital, Mansoura, Egypt
2 Internal Medicine Department, Menoufia University, Menoufia, Egypt
3 Internal Medicine Department, Diabetic Foot Team, Mansoura University, Mansoura, Egypt
4 Clinical Pathology Department, Mansoura University, Mansoura, Egypt

Date of Submission11-Dec-2016
Date of Acceptance11-Apr-2017
Date of Web Publication27-Aug-2018

Correspondence Address:
Ahmed M Abd El Fattah
Internal Medicine Department, Mansoura General Hospital, Mansoura, Dakahlia
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/mmj.mmj_658_16

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  Abstract 


Objective
The objective of this study was to determine the efficacy of low-frequency ultrasound (LFU) in chronic wound healing and infection outcome in diabetic foot ulcers.
Background
Around 15% of patients with diabetes will develop foot ulcers at some point in their life, making them 30–40 times more likely to undergo amputation due to a nonhealing foot ulcer than the nondiabetic population. Debridement plays a significant role in the healing of diabetic foot ulcers.
Patient and methods
This randomized clinical trial was conducted on 46 patients with diabetes, recruited from the Diabetic Foot Clinic at Mansoura and Menoufia Universities, Egypt. All patients with diabetes (type I and type II) who had chronic diabetic foot ulcers without severe arterial insufficiency, with ankle brachial indices of at least 0.6, and without severe limb-threatening infections were included.
Results
Patients were divided into two groups – group 1 received ultrasound-assisted wound (UAW) therapy in conjunction with standard wound care (n = 23), and the other group received only standard wound care. Patients were followed-up for 3 months. The complete healing rate in the present study population was 30.34% (control group = 17.39%, UAW group = 43.47%). The mean wound size reduction was significantly higher in the UAW group only in the second-week and third-month follow-ups. The number of infected ulcers was reduced by ultrasound debridement more than surgical debridement (control group = 5, UAW group = 11) at the end of the study, but with no significant difference (P = 0.148). A significant difference in healing ratio was found in patients with ultrasound debridement and initial wound culture (P = 0.01).
Conclusion
In diabetic foot ulcers, LFU debridement accompanied by standard wound care has a beneficial effect on wound healing and wound infection. LFU debridement can initially accelerate ulcer healing; however, there was no significant difference between the two modalities in the healing rate after 3 months.

Keywords: debridement, diabetic foot ulcers, foot infection, ultrasound, wound healing


How to cite this article:
Abd El Fattah AM, Shaaban M, Gawish H, El Mashad N, El Deen Dawood A. Effect of ultrasound-assisted debridement on wound healing and infection outcomes in diabetic foot. Menoufia Med J 2018;31:462-6

How to cite this URL:
Abd El Fattah AM, Shaaban M, Gawish H, El Mashad N, El Deen Dawood A. Effect of ultrasound-assisted debridement on wound healing and infection outcomes in diabetic foot. Menoufia Med J [serial online] 2018 [cited 2018 Sep 19];31:462-6. Available from: http://www.mmj.eg.net/text.asp?2018/31/2/462/239762




  Introduction Top


The prevalence of diabetes mellitus (DM) is increasing worldwide. About 15% of patients with diabetes will experience a diabetic foot ulcer in their lifetime and precedes 84% of all diabetes-related lower-leg amputations [1]. Diabetic foot ulcers (DFUs) contribute significantly toward the morbidity and mortality of patients with DM [2]. Foot ulceration has been reported as the leading cause of hospital admission and amputation in individuals with diabetes. Diabetes-related foot ulcers require multidisciplinary management and best practice care, including debridement, offloading, dressings, management of infection, modified footwear, and management of extrinsic factors [3].

Ulcer debridement is a commonly applied management approach involving removal of nonviable tissue from the ulcer bed. Different methods of debridement include autolytic debridement through moist wound healing, mechanical debridement utilizing wet-to-dry dressings, theatre-based sharps debridement, biological debridement, nonsurgical sharps debridement, and newer technology such as low-frequency ultrasonic (LFU) debridement [3]. There are numerous evidence-based wound debridement techniques that promote wound healing. However, some of these techniques may cause discomfort and pain to the patient and can be costly for the healthcare provider. A new, noninvasive wound debridement technique known as LFU debridement has been used for the removal of unhealthy tissue and bacterial load in wound management in the clinical setting [4].

Foot infections are the most common problems in persons with diabetes. These individuals are predisposed to foot infections because of a compromised vascular supply secondary to diabetes. Local trauma and/or pressure (often in association with lack of sensation because of neuropathy), in addition to microvascular disease, may result in various diabetic foot infections that run the spectrum from simple, superficial cellulitis to chronic osteomyelitis [5].

LFU debridement (20–60 kHz) is one of the novel techniques of wound debridement that is less traumatic, less painful, and can achieve faster healing rates. LFU debridement is a noncontact debridement method that is performed at a 5–15 mm distance from the wound surface. This can accelerate the wound healing process by removing necrotic tissue, fibrosis, exudate, and bacteria with minimum bleeding and pain [6] [Figure 1].
Figure 1: Ultrasound debridement using Sonoca 180 [7].

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  Materials and Methods Top


The present study was approved by our institution's local ethics committee, and written informed consent was given by all patients.

This randomized clinical trial compared the effects of LFU waves on diabetic foot ulcer healing process and wound infection outcome in patients who received a combination of LFU waves plus standard wound care therapy in comparison with patients who received only standard wound care treatment. The present study was performed at the Diabetic Foot Clinic at Mansoura and Menoufia Universities, Egypt, from December 2014 to December 2015. Inclusion criteria were as follows: all patients with diabetes (type I and type II) with chronic diabetic foot ulcers without sever arterial insufficiency, ankle brachial index of at least 0.6, and without severe limb-threatening infections. All patients signed an informed consent form.

Patients (n = 46) were randomly divided into two groups on the basis of a simple randomization method. One group received the combination therapy of LFU waves plus standard wound care (debridement group), and the other group received only standard wound care treatment (control group). Demographic and clinical information including full medical history, foot ulcer risk factors, associated diseases, neuropathy, laboratory tests, physical examination, and wound assessment from each visit were collected following enrollment into the study. The degree of neuropathy and muscle stretch reflexes were assessed by the Michigan Neuropathy Screening Instrument. Laboratory tests to check blood glucose, lipid profile, glycated hemoglobin, and liver and kidney function were requested for all patients.

Wound assessment

Patients visited our facilities once a week during the study period. Wounds were evaluated at each visit with a flexible ruler laid alongside the pressure ulcers. Patient compliance regarding offloading, medications, and daily dressing changes was assessed. Total contact casting, half shoe, felted foam, and pads were used more as offloading methods, and all patients received antibiotics. Wounds were assessed on the basis of the Texas classification. Patients were followed-up for 3 months from the first debridement or until complete wound healing (i.e., wound closure with complete epithelialization without purulent discharge) was observed. The LFU used in this study was the Sonoca 180 (Soring Incorporated, Germany) [Figure 1].

Statistical analysis

All statistical analyses were performed using statistical package for the social sciences program (version 15) on Windows 7.

Data description was carried out as follows:

  1. Frequencies and proportions for qualitative data
  2. Mean ± SD for normally distributed quantitative data
  3. Medians and ranges for nonparametric data, diagnosed by the Kolmogorov–Smirnov test.
  4. Data analysis was carried out to test for statistically significant differences between groups:


  1. For qualitative data (frequency and proportion), the χ2-test was used
  2. For quantitative, normally distributed data (mean ± SD), the following tests were used:


    1. Student's t-test was used to compare two groups
    2. One-way analysis of variance was used to compare more than two groups.


    Intragroup difference was determined using a post-hoc least significant difference test.


  1. For nonparametric data (median and range), the Kruskal–Wallis test was used to compare more than two groups, and
  2. The Mann–Whitney U-test was used to compare between two groups.


  3. P was significant at less than 0.05 and confidence interval of 95%.



  Results Top


Comparison of the demographic and clinical characteristics of patients of the two groups is presented in [Table 1]. In the control group, there were 11 male and 12 female patients, with mean age ranging from 35 to 67 years and mean of diabetes duration from 3 to 35 years. Among all, three patients had DM type I, and 20 patients had DM type II. Initial HBA1c for the patients ranged from 7.1 to 11.9. Initial fasting blood sugar for the patients ranged from 212 to 456 mg/dl. HBA1c after 3 months ranged from 6.9 to 11.4, and fasting blood sugar after 3 months ranged from 21 to 377 mg/dl. According to the Texas classification of ulcers, seven patient were 1A, three patients 2A, nine patients 1B, and four patients 2B [Figure 2]. We found three pressure ulcers, five neuropathic ulcers, and 15 combined ulcers (neuropathic and pressure). Initial cultures showed two ulcers with no growth, 38 ulcers with Gram-positive infections, five ulcers with Gram-negative infections, and one ulcer with mixed infection. One patient was on oral therapy, and 22 patients were on insulin therapy [Table 1].
Figure 2: The University of Texas wound classification (http://www.nhsgrampian.org/guidelines/diabetes/topics/Figu1UnivOfTexaClasSystForDiabFo.html).

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Table 1: Demographic, clinical, and laboratory data of the different groups of patients

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In the debridement group, there were 13 males and 10 females with the mean ranging from 32 to 58 years and mean diabetes duration ranging from 5 to 29 years. Two patients had DM type I, and 21 patients had DM type II. The initial HBA1c for patients ranged from 6.9 to 11. Initial fasting blood sugar of patients ranged from 128 to 412 mg/dl, HBA1c after 3 months ranged from 6.7 to 11.5, and fasting blood sugar after 3 months ranged from 129 to 379 mg/dl. According to the Texas classification of ulcers, four patients were 1A, two patients 2A, eight patients 1B, and six patients 2B [Figure 2]. Five patients had pressure ulcers, six neuropathic ulcers, and 12 combined ulcers (neuropathic and pressure). Initial cultures showed 19 ulcers with Gram-positive infections and four ulcers with Gram-negative infections. One patient was on oral therapy, and 19 were on insulin therapy [Table 1].

The multivariate logistic regression analysis to determine factors affecting healing of ulcers (age, sex, DM type, DM duration, HBA1c initial, FBS initial, and initial culture organisms) revealed that the initial FBS level has a strong influence on diabetic wound healing [Table 2].
Table 2: Factors affecting healing (sex, age, diabetes type, diabetes duration, initial HBA1c, initial fasting blood sugar, initial culture organism)

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In our study, the number of healed ulcers at the end of the 12th week was 14, and the number of unhealed ulcers was 32. The ulcers debrided by ultrasound showed 10 healed ulcers and 13 unhealed ulcers, and the ulcers debrided by surgical debridement showed four healed ulcers and 19 unhealed ulcers. There was no significant difference in the number of healed ulcers between the two groups at the end of the 12th week [Table 3].
Table 3: Relationship between type of debridement and number of healed ulcers

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A significant difference in the size of the wound after 2 weeks (P = 0.049) was found between both groups. A significant difference in the size of the wound at 12 weeks (P = 0.04) was also found between the two groups [Table 4].
Table 4: Comparison of size of the wound in different types of debridement within 3 months of treatment and comparison of healing ratio in patients with different types of debridement

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No significant difference in healing ratio was found between the two groups at the end of 12 weeks [Table 4].

A significant difference in healing ratio (P = 0.02) was found between patients with ulcers with different microbiological culture findings after 3 months [Table 5].
Table 5: Comparison of healing ratio in ultrasound debridement and type of organism of the initial wound culture and after 3 months

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A significant difference in healing ratio in patients in the ultrasound debridement group (P = 0.01) was found between initial, different microbiological culture findings [Table 5].


  Discussion Top


DM is associated with numerous complications related to microvascular, macrovascular, and metabolic etiologies. One of those is diabetic foot syndrome, which has been defined as an array of foot abnormalities, resulting from peripheral neuropathy, macroangiopathy, and other consequences of metabolic disturbances. Different causal factors may be present alone; however, they are more likely to occur in combination in patients with DM [8]. Diabetes-related foot disease remains one of the most frequent causes of diabetes-specific hospital admissions. Every year 5% of diabetic patients develop a foot ulcer. Approximately 15% of all diabetics will develop some foot problem during the course of their illness [9].

Previous studies have suggested that LFU waves have an effective role in the treatment of chronic wounds. For example, Kavros et al. [10] observed that the rate and speed of complete healing in a group receiving ultrasound-assisted wound treatment in combination with standard wound care was significantly higher than the control group that received only standard wound care.

In our study, a significant difference in the size of the wound after 2 weeks (P = 0.049) was found between the two groups. Moreover, a significant difference in the size of the wound at 12 weeks (P = 0.04) was found between the two groups. Amini et al. [7], Voight et al. [11], and Driver et al. [12] agree with these findings, and state that noncontact LFU for the treatment of chronic wounds is associated with consistent and substantial wound size reductions, as well as favorable rates of healing.

The therapeutic benefit to using ultrasound in wound care is further demonstrated by the fact that emitted acoustic energy upregulates and increases cellular activity [11].

No significant difference in healing ratio was found between patients with ulcers having ultrasound debridement and patients with ulcers having surgical debridement at the end of the 12th week. Amini et al. [7], Watson et al. [13], and Cullum et al. [14] agree with this finding.

About half of diabetic foot ulcers are clinically infected at presentation. DFIs cause substantial morbidity, and at least one in five results in a lower-extremity amputation. Amputation is even more likely when DFI and foot ischemia coexist. In fact, DFIs are now the predominant proximate trigger for lower-extremity amputations worldwide [15].

A significant difference between the healing ratio was found in patients with ulcers undergoing ultrasound debridement (P = 0.01) with initial, different microbiological culture findings. This was in agreement to McDonald and Nichter [16] who reported that ultrasound debridement is an effective treatment for contaminated wounds.

In our study, we found that initial fasting blood sugar level has an important influence on wound healing (P = 0.041); this was in agreement with Shojaiefard et al. [17].

Considering the advantages of LFU waves in the treatment of chronic wounds, which include being easy to use for the clinician, painless, less stressful, and better accepted by patients, as well as having a lower cost and reduced rate of amputation, this modality is of great interest for the treatment of diabetic ulcers. Further studies with a focus on wounds with high severity are recommended to evaluate the effectiveness of these ultrasound waves on the healing process of chronic wounds.


  Conclusion Top


Ultrasound debridement has a beneficial effect on diabetic wound healing and diabetic wound infection.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
Brem H, Tomic-Canic M. Cellular and molecular basis of wound healing in diabetes. J Clin Invest 2007; 117:1219–1222.  Back to cited text no. 1
    
2.
Al Kafrawy NA, Mustafa EA, Dawood ADA, Ebaid OM, Ahmed Zidane OM. Study of risk factors of diabetic foot ulcers. Menouf Med J 2014; 27:28–34.  Back to cited text no. 2
    
3.
Michailidis L, Williams CM, Bergin SM. Comparison of healing rate in diabetes-related foot ulcers with low frequency ultrasonic debridement versus non-surgical sharps debridement: A randomised trial protocol. J Foot Ankle Res 2014;7:1.  Back to cited text no. 3
    
4.
Shannon MK, Williams A, Bloomer M. Low-frequency ultrasound debridement (Sonoca-185) in acute wound management: a case study. Wound Pract Res 2012; 20:200–205.  Back to cited text no. 4
    
5.
Lipsky BA, Giordano P, Choudhri S, Song J. Treating diabetic foot infections with sequential intravenous to oral moxifloxacin compared with piperacillin-tazobactam/amoxicillin-clavulanate. J Antimicrob Chemother 2007; 60:370–376.  Back to cited text no. 5
    
6.
Breuing KH, Bayer L, Neuwalder J, Orgill DP. Early experience using low-frequency ultrasound in chronic wounds. Ann Plast Surg 2005; 55:183–187.  Back to cited text no. 6
    
7.
Amini S, ShojaeeFard A, Annabestani Z, Shaiganmehr Z, Rezaie H, Larijani B, et al. Low-frequency ultrasound debridement in patients with diabetic foot ulcers and osteomyelitis. Wounds 2013;25:193–198.  Back to cited text no. 7
    
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Gumaa MM, Shwaib HM, Ali SM. Diabetic foot lesions predicting factors, view from Jabir Abu-Alaiz diabetic centre in Khartoum, Sudan. J Diabetic Foot Complications 2016; 8:6–17.  Back to cited text no. 8
    
9.
Shah SF, Hameed S, Khawaja Z, Abdullah T, Waqar SH, Zahid. Evaluation and management of diabetic foot: A multicentre study conducted at Rawalpindi, Islamabad. Ann Pak Inst Med Sci 2011;7:233–7.  Back to cited text no. 9
    
10.
Kavros SJ, Liedl DA, Boon AJ, et al. Expedited wound healing with noncontact, low-frequency ultrasound therapy in chronic wounds: a retrospective analysis. Adv Skin Wound Care 2008; 21:416–423.  Back to cited text no. 10
    
11.
Voigt J, Wendelken M, Driver V, Alvarez OM. Low-frequency ultrasound (20-40 kHz) as an adjunctive therapy for chronic wound healing: A systematic review of the literature and meta-analysis of eight randomized controlled trials. Int J Low Extrem Wounds 2011;10:190–9.  Back to cited text no. 11
    
12.
Driver VR, Yao M, Miller CJ. Noncontact low-frequency ultrasound therapy in the treatment of chronic wounds: a meta-analysis. Wound Repair Regen 2011; 19:475–480.  Back to cited text no. 12
    
13.
Watson JM, Kang'ombe AR, Soares MO, Nelson EA, Ling-Hsiang C, Gill W, et al. Use of weekly, low dose, high frequency ultrasound for hard to heal venous leg ulcers: the VenUS III randomized controlled trial. BMJ 2011; 342:d1092.  Back to cited text no. 13
    
14.
Cullum NA, Al-Kurdi D, Bell-Syer SE. Therapeutic ultrasound for venous leg ulcers. Cochrane Database Syst Rev 2010; 6:CD001180.  Back to cited text no. 14
    
15.
Fisher TK, Wolcott R, Wolk DM, Bharara M, Kimbriel HR, Armstrong DG. Diabetic foot infections: A need for innovative assessments. Int J Low Extrem Wounds 2010;9:31–6.  Back to cited text no. 15
    
16.
MacDonald WS, Nichter LS. Debridement of bacterial and particulate contaminated wounds. Ann Plast Surg 1994; 33:142–147.  Back to cited text no. 16
    
17.
Shojaiefard A, Khorgami Z, Larijani B. Independent risk factors for amputation in diabetic foot. Int J Diabetes Dev Ctries 2008; 28:32–37.  Back to cited text no. 17
    


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]



 

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