Larval therapy for venous leg ulcers - Literature review Example

?Larval therapy for venous leg ulcers Introduction Venous leg ulcers are one of the most difficult wounds to manage. For many nurses, it can prove tobe a significant challenge to resolve this medical issue, especially for diabetic patients and long-term care patients. There are various nursing management techniques for venous leg ulcers, and these interventions range from medical, surgical, to alternative therapies. One of these alternative therapies is the larval therapy, where maggots are placed on the wound. The maggots then proceed to consume the infections present in the wound and eventually ‘clean’ up the ulceration. This study shall provide a critical appraisal of larval therapy for venous leg ulcers. Initially, the background and aetiology of the disease shall be provided, followed by a critical appraisal of eight studies pertinent to this topic. This study is being carried out in order to establish a scholarly and comprehensive assessment of available literature on larval therapy on venous leg ulcers; it also seeks to assess the future general applicability of this therapy in the clinical practice. Body Overview Venous leg ulcers are chronic and non-healing wounds or ulcerations on the leg or foot (NHS Choices, 2010). It is usually accompanied with symptoms of pain, itching, and inflammation in the affected area. Venous leg ulcers are seen when there is a persistent high pressure of blood in the veins of the legs which can later cause damage to the skin. Venous leg ulcers affect 1 in 500 individuals in the UK with rates increasing sharply with age (NHS Choices, 2010). About one person in every 50 over the age of 80 has a high risk for venous leg ulcers. Risk factors for this disease include immobility, obesity, advancing age, and varicosities (NHS Choices, 2010). The prognosis for venous leg ulcers is more or less good, however, with diabetic and elderly patients, the management may take longer. Nevertheless, with appropriate treatment, the healing can be ensured. Venous leg ulcers are caused by damage to the veins located in the legs (NHS Choices, 2010). Venous problems can be seen with the valves in the veins improperly functioning. As a result, blood flows backwards into the previous valves causing pooling in the lower trunks of the veins. With increased pressure in the veins, damage to the veins, and later the skin can become apparent (NHS Choices, 2010). Constant high blood pressure in the legs can cause leaks which then cause swelling and damage to the skin, thereby leading to the ulcerations. Critical appraisal In the study by Dumville, et.al., (2009), the authors clearly presented the goals of their research which was basically to compare the clinical effectiveness of larval therapy with standard debridement techniques for necrotic leg ulcers. The relevance and importance of the research was indicated by the authors, mostly in relation to cost effectiveness of various therapies for venous leg ulcers (Dumville, et.al., 2009). This goal is relevant because of the fact that the cost of medical interventions has increased and the need to decrease and manage medical costs for patients and for health care in general has become a more imperative requirement in the current age of health and economic crisis. The introduction and the literature review were able to establish the concept and the idea behind the research, including its possible benefits to the clinical practice. The hypothesis has not however been clearly stated, but can be implied from the initial chapters of the study. The author implies the higher benefits which can be gained from the use of larval therapy for venous leg ulcers. The main terms of the study are defined and can easily be deduced from the authors’ presentation. The research also presented a well focused question, including a clearly defined population specifically defined through the inclusion and exclusion criteria. The interventions to be used by the authors were also specified with specific expected outcomes defined. In assessing the design chosen, the authors were able to use an appropriate design, one which places high in the hierarchy of evidence. This design was able to provide a navigable means for the research issue to be answered. The methods and procedures were clearly described, including the selection and recruitment of respondents, the manner by which the interventions would be administered, and the outcome measures to be assessed for each respondent. Based on the data given, the study could easily be replicated. The inclusion criteria specified respondents with venous leg ulcers with at least 25% of the wound covered by slough. Patients excluded were those who were pregnant or lactating, who were allergic to hydrogel, had grossly oedematous legs, and those taking anticoagulants (Dumville, et.al., 2009). The selected participants are representative of the selected population and fit the goals of this research. They were also orientated about the research and its implications. The authors did not however specify some of the processes involved to the respondents. There was no calculation carried out on the sample size as the respondents were not taken from the general population. The respondents were randomly assigned to intervention and control groups even as the selection process was not random. There was no blinding method applied because it was not appropriate for the study. The outcome measures were applied to the respondents and data was recorded and entered into the computer program for appropriate collation. No bias in the data collection was apparent because all the researchers were able to participate and monitor the process, allowing for a greater transparency and objectivity in the data collection. The data is clearly presented through tables with P-values indicated and statistical computations indicated. Ethical standards were applied throughout the research. The process of informed consent was however not indicated by the researchers. Nevertheless, the dignity and the rights of the respondents were respected and secured. The results were not generalisable to a bigger population because the number of respondents was minimal. The results however are relevant to policy makers and participants, including family members. The discussion of the results is very much related to the question raised and the results have been interpreted clearly and appropriately based on results presented previously. In the Soares, et.al., (2009) study, the authors sought to establish the cost effectiveness of larval therapy compared with hydrogel in the management of leg ulcers. This study was significant because it specifically measures the comparative cost of the interventions for venous leg ulcers. As was mentioned previously, it is important to seek cost effective interventions in the current financial and health budget crisis. The introduction and the literature review established the framework of the research, as well as the impact of the research in actual clinical practice. The hypothesis was clearly indicated and mostly related to the fact that previous studies refer to the benefits of larval therapy. The terms of the study were not specifically defined, but a general understanding of larval therapy and hydrogel therapy was defined by the authors. The research question was specified and explained. The population of respondents was also specified through the inclusion and exclusion criteria indicated by the researchers. The interventions were appropriately explained, and the outcomes to be assessed were also defined. Based on the study design, the authors applied the cost effectiveness analysis, applying randomised and equal randomisation processes. It was also appropriate for the goals of the research which primarily referred to comparing the costs of the therapies. The design was able to establish a strong measure for the research issue raised. The methods of selecting respondents, as well as the inclusion criteria were also specified. No exclusion criteria were however specified by the authors. The methods of the administration of the intervention and the measurement of cost outcomes for each therapy were also specified by the authors. The respondents chosen were oriented about the interventions and the implications of the study were evaluated. The statistical treatment involved the inverse probability weighing which was able to estimate time of wound healing, costs, as well as quality of life indicators. The authors did not mention how the sample size was computed, and the results were not yet adequate. Leg ulcers often recur and the study did not measure recurrence and its economic impact beyond the period of the study. The study nevertheless indicated that larval therapy produces results highly comparable with hydrogel therapies. Time for healing was recorded by the nurses and independently assessed by blinded investigators via digital pictures. Ethical standards were observed by the researchers. Informed consent was secured and the dignity of the subjects was also respected. The results could be applied to a bigger population; legislators, as well as practitioners can also learn from these results as it indicates favourable alternatives for leg ulcers treatment. The discussion of the results linked the important elements of the research, from the concepts in the introduction, and on to the results. The results more or less echo the other ideas from previous studies – that larval therapy is also a cost effective treatment for venous leg ulcers. In the study by Sherman (2003), the author’s goal was mainly to evaluate the efficacy of maggot therapy in treating foot and leg ulcers of diabetic patients who have failed conventional therapy. This was a relevant study because many diabetic patients suffer from leg ulcers and are often difficult to treat because they have poor healing ability. The initial chapter of this study – the introduction as well as the literature review established a good background and foundation for this research as it outlined the trends of leg ulcers among diabetic patients and the impact of this disease on the quality of these patent’s lives. The hypothesis was not specified by the authors. However, it is implied from the text that using larval therapy can be beneficial for leg ulcer patients. The different terms of the study were defined and specified by the authors and the reader was able to gain a better understanding of larval therapy and how applies to leg ulcers. The population for the sample group was not specified through specific inclusion and exclusion criteria. The intervention to be carried out was also explained and the process of applying these to the respondents was explained to them. The outcome measures were also explained; this included the measurements of wound healing rates and manifestations of healing. The study design was retrospective comparison of changes. This was appropriate for the study, however, a more current prospective study could have been better applied for measuring better results. No randomisation applications were specified by the authors. This reduced the generalisability of the study results. The method of administering the treatment was however specified by the authors with the outcome measures also clearly detailed. The procedures were explained to the respondents, however, adequate informed consent practices were not specified by the authors. This reduced the validity and the reliability of the research process. The statistical treatment ANOVA was applied to the study and this treatment was able to establish a clear pattern for the study and the research issues raised. The study was able to reveal that maggot therapy was more effective in wound healing for foot and leg ulcers in male diabetic veterans as compared to conventional care (Sherman, 2003). The discussion portion was able to piece and link the research into a one coherent study. The link from the research issues, and on to the results and implications were designated by the authors. The overall results indicated strong support for larval therapy in the management of leg ulcers for the leg ulcers of diabetic patients. Martin’s (2007) study was a systematic review which sought to establish the efficacy of maggot debridement therapy of leg ulcers, primarily looking into healing time and amputation rates. The studies included in the review included a: randomised controlled trial, case control study, case cohort study, a report, and a retrospective noncomparative cohort study. This systematic review saw most of the studies apply randomisation methods which helped ensure the generalizability of the results. Inclusion criteria also established the studies to be included in the review. A sufficient background was presented by the authors and was able to provide a clear concept and framework for the review and for the intervention. The efficacy of the intervention was adequately assessed by comparing larval therapy with traditional treatments. Level of evidence included the higher ranking evidence or research in the hierarchy. This helped provide a strong basis for appropriate treatment in leg ulcers. The authors also specified expected outcomes which indicated how the expected healing times and the amputation rates. These rates and indicators were able to provide adequate measures for the results in each study. The results of the study echoed the results as seen in previous studies, that larval therapy presented faster healing times and lesser amputation incidents, as compared to traditional treatments. It is important to note however that most of the studies had limited sample populations which often hampered the possibility of carrying out randomised controlled studies with larger populations. In effect, this limited the generalisability of the results. Due to limited number of respondents, the randomisation process for assigning treatments was also not applied in some of the studies. Moreover, the sample selection was also not randomised due to small populations in some of the studies. Nevertheless, the authors attempted to protect the credibility and reliability of their studies by applying randomisation where possible and by securing blinding methods for the nurses administering the interventions and measuring outcomes. The discussion was able to provide a clear and comprehensive assessment of the studies included in the review. It was also able to link and coordinate the results based on the research question raised. The studies chosen were peer-reviewed and were highly relevant to the general goals of the systematic review. Cambal, et.al. (2006) carried out their study in an attempt to establish a maggot debridement therapy and evaluate its efficacy in the management of chronic leg ulcers in patients where conventional therapy has failed. The study was carried out as a case report covering 10 patients with venous leg ulcers, 7 of the patients having diabetes. The purpose of the paper is currently relevant in terms of determining effective treatments for venous leg ulcers. The introduction and literature review provided a background and context for the study. The details were however limited as an insufficient number of studies were evaluated by the authors. The problem statement was nevertheless clear and was well supported by the literature review and background of the study. The application of larval therapy was evaluated in relation to conventional therapy which the authors specifically described in their study. The details were sufficient to allow replication of the study methods. The methods of sample selection were however not specified by the authors. No randomization was carried out and inclusion as well as exclusion details were not detailed by the authors. This reduced the generalizability and the reliability of the study. The ethical elements of informed consent were also not specified by the authors, and this also reduced the validity of the study. The outcome measures for the respondents were also not specified; the authors however mentioned that they measured healing and granulation rates for each respondent within the days and weeks following each treatment. These outcome measures were specifically linked to the expected healing process for each respondent. The results of the study were based on the healing rates for each respondent, comparing the two therapies applied. The study was a qualitative study and the results were based on a case-specific assessment of each respondent based on the overall impact of larval therapy. The results indicated that maggot debridement therapy was more effective than conventional therapy in the management of venous leg ulcers. These results are based on a small population and not applicable to a generalized group of respondents sharing similar qualities. The discussion helped provide further support for the study results but did not go into specific detail on the various variables essential for the success of the therapy. The authors acknowledged that their sample population was small, but they point out that it is consistent with previous studies on the subject matter. The results also indicate strong support for the preferred use of larval therapy over conventional therapy. Major improvements in this study can be carried out in terms of increasing the sample population, specifying compliance with ethical requirements, objective selection of respondents, as well as inclusion and exclusion criteria. These elements could have improved the reliability of these results, as well as their generalizability. In another study related to the cost effectiveness of larval therapy for the management of leg ulcers, Wayman and colleagues (1999) sought to compare the cost required in the use of larval therapy and that of hydrogels in the management of venous leg ulcers. The study was carried out as a quantitative cost analysis study which was very much appropriate for the goals of the research. This study was also significant because it considered an aspect of treatment relevant to this current economic crisis and rising health costs. The trend of patient centred care is now on cost effectiveness and on using treatments which can provide the most benefits for patients. The introduction and literature review was able to provide a framework for the research, including the potential benefits it can bring to the management of venous leg ulcers. The hypothesis was not specifically stated but could be implied from the general tone of the initial discussion of the authors – that larval therapy is the most cost-effective therapy for venous leg ulcers. The terms used in the study were however not adequately specified by the authors but were adequately explained in the text of the study itself. The research question was also specified and explained. The sample population was not adequately explained by the authors. The inclusion and exclusion criteria were specified and were very much applicable to the goals of this research. The interventions for the respondents were adequately explained by the authors – hydrogel therapy and larval therapy. The outcome measures for the research were mostly based on whether or not debridement occurred within the month following the intervention and the amount of slough was also calculated; for cost, the number of nursing visits as well as cost of nursing time and dressings were used to measure cost effectiveness (Wayman, et.al., 1999). The study design was appropriate for this study because it supported the goals of the research. The manner by which the intervention was administered was detailed and specified by the authors, allowing for the future replication of the study. Ethical elements including informed consent were however not mentioned by the authors and this reduced the validity of the study results. The manner by which the sample size was computed was not mentioned by the authors. This also reduced the reliability of the study. The authors were however able to establish results similar to the Soares study, that the costs of larval therapy are comparable to the costs of hydrogel therapy. Appropriate blinding of the assessment was applied by the authors and this allowed for the objective assessment of the respondents’ leg ulcers. The authors acknowledged that they covered a limited population which can be increased in future studies in order to improve the generalizability of results. The results are relevant for clinicians and health administrators who can recommend this treatment for other patients sharing similar qualities and diseases. The discussion portion was able to adequately provide coordinated and specific links between the concepts in the introduction and the results. The conclusion was well supported and drawn from the results and discussion. No logical fallacies were seen. The patient perspective and preferences were considered in the study by Petherick, et.al., (2006). The study sought to assess patient preferences – hydrogel or larval therapy, and between bagged larvae and standard therapy. This study is very much relevant because it focuses on patient preferences and patient-centred care. These patient preferences are important in the current management of chronic illnesses because it can help improve patient outcomes and improve patient cooperation during treatment. The introduction and literature of the study was clear and detailed, providing a framework and basis for the current study being conducted. The research question flowed naturally from such concepts and in effect was well supported by previous studies and analysis on the subject matter. The design chosen was also appropriate because it helped provide a strong and manoeuvrable framework for the research in general. The design was also adequately explained and supported by the researchers. The selection of the respondents was also specified through the inclusion and exclusion criteria. The designation of the respondents for each form of treatment was also randomised. The interventions for each respondent were adequately described by the authors and this allowed the future replication of the data. The authors did not mention the application of blinding methods during the assessment of the healing process for each respondent. The results indicated no significant results as to the preference in treatment for venous leg ulcers. In general, there was no widespread resistance on the form of therapy used. In terms of specific details however, patients preferred the larval therapy as compared to the hydrogel therapy because the former was able to provide faster and better outcomes in their healing. About 25% of respondents however refused to use the larval therapy under any circumstances or methods of containment (Petherick, et.al., 2006). These results provide an alternative glimpse into the application of larval therapy; they provide a patient-based insight which is sometimes not given enough attention in the management of leg ulcers and in the general application of nursing interventions. The results were adequately supported by statistical measures and linkages to the literature within the text. The discussion provided connections within the study on the conceptual framework and the results. The conclusions were also well supported. Steenvoorde, et.al., (2007) sought to carry out a prospective study in order to gain more insights in patient and wound qualities influencing outcomes in the application of maggot debridement therapy of infected ulcers. The introduction and literature review provided a strong and detailed background for the study and the subsequent research question raised. The selection of the population was specified through the inclusion and exclusion criteria. The designation of each respondent to the various interventions was based on the forms of treatment being compared. The procedure followed during the intervention process was detailed by the authors, thereby allowing the future replication of the study. The results were based on outcome measures which related to rates of healing. The multivariate analysis provided a thorough analysis and correlation of the results. Elements like gender, obesity, diabetes mellitus, smoking, location of the wound, and wound duration was also correlated with the study results. These variables did not appear to impact on the results. The authors concluded that some patient qualities do not seem to impact on wound healing and on the efficacy of maggot debridement therapy for venous leg ulcers. Moreover, older patients are also less likely to benefit from larval therapy. The authors were able to comply with the informed consent requirements of ethical research. This helped ensure the reliability of the study results. This study also assigned the treatments via randomised methods of classification for each respondent. This allowed for improved validity and reliability for the results. The discussion specifically discussed the links between the variables and the results established. The authors were not able to specify any limitations during their research. They were however able to provide a basis for future research on a similar subject matter. Conclusion Based on the studies presented above, larval therapy is a highly effective method of treatment for venous leg ulcers. It provides an effective alternative therapy as it presents with faster healing periods, improved health outcomes, and less cost for the patient. More patients also seem to prefer the method of treatment, even as others declare that they would never opt for this treatment. The limitations of the study mostly pertain to the sample sizes which could have covered a larger population; their recommendations for future studies include bigger populations in order to improve the generalizability of the study results. Some of the studies were also not able to apply randomised selections and designations for their respondents. Nevertheless, the trends and overall results were consistent and echoed results derived from previous studies. In general, larval therapy is comparable to hydrogel therapy in terms of cost effectiveness; and it provides more effective outcomes in healing as compared to other conventional forms of treatment. References Cambal, M., Labas, P., Kozanek, M., and Takac, P., 2006. Maggot debridement therapy. Bratisyl Lec Listy, 107(11-12), pp. 442-444. Dumville, J., Worthy, G., Bland, M., Cullum, N., and Dowson, C., 2009. Larval therapy for leg ulcers (VenUS II): randomised controlled trial. BMJ, 338: b773. Martin, D., 2003. Maggot debridement therapy in the treatment of nonhealing chronic wounds. Wayne State College [online] Available at: http://soar.wichita.edu/dspace/bitstream/handle/10057/1089/pa0705013.pdf;jsessionid=D8F53B5BEBA76110A169D46D484D8BE4?sequence=1 [Accessed 10 May 2012]. NHS Choices, 2010. Leg ulcer, venous [online] Available at: http://www.nhs.uk/Conditions/Leg-ulcer-venous/Pages/Introduction.aspx [Accessed 10 May 2012]. Petherick, E., O’Meara, S., Spilsbury, K., Iglesias, C., and Nelson, E., 2006. Patient acceptability of larval therapy for leg ulcer treatment: a randomised survey to inform the sample size calculation of a randomised trial. BMC Medical Research Methodology, 6:43 Sherman, R., 2007. Maggot Therapy for Treating Diabetic Foot Ulcers Unresponsive to Conventional Therapy. Ann R Coll Surg Engl., 89(6), pp. 596–602. Soares, M., Iglesias, C., Bland, M., and Cullum, N., 2003. Cost effectiveness analysis of larval therapy for leg ulcers. Diabetes Care, 26(2), pp. 446-451 Steenvoorde, P., Jacobi, C., Van Doorn, L., and Oskam, J., 2009. Maggot Debridement Therapy of Infected Ulcers: Patient and Wound Factors Influencing Outcome – A Study on 101 Patients with 117 Wounds. BMJ, 338: b825. Waymant, J., Nirogojit, V., Walker, A., and Sowinskia, A., 2000. The cost effectiveness of larval therapy in venous leg ulcers. Journal of Tissue Viability, 10(3), pp. 91-94. Read More