Advantages And Limitations Of Topical Negative Pressure Therapy

Advantages And Limitations Of Topical Negative Pressure TherapyNegative pressure hurt therapy (NPWT) is a upstart order apply for improving infract meliorate. It influences granulation recoilation, bacterial colonization, and increasing anguish blood flow. Although this rule has been use explosively for annoy improve, its influences are not cleared enough. So the main aim of this review article is to weight up the benefits and problems associated with this method.Method An electronic search was done via Pubmed, Embase and ISI web of knowledge selective information from 1960 to 2010. The abstracts and titles of each paper were analysed and selected according to especial parameters.Result The results of the relevant literature were characterized establish on the benefits and problems associated with use of this method.Discussion Direct comparison of NPWT with some opposite functional method is difficult. Although there are some search to plunk for the effectiveness of using this new method on hurt healing, more cookled clinical trials are desireed to defiantly prove that the NPWT is less expensive and more effective wound care modality.A wound is defined as a emit in the peel which is usually caused by cuts or scraps. The selection of the manipulation methods depends upon the severity of the wounds (how serious they are). Healing is a response of the injury that sets into motion a sequence of events. There are classically four stages associated with wound healing which let in haemostasis, inflammation, proliferation and remodelling (Hart, 2002, Stephens and Thomas, 2002, OKane, 2002). Many factors fag interact with one or more phases of wound healing process which can facilitate or decrease its rate, such as local and organisationatic factors. Local factors are those which directly influence characteristics of wound itself, while systematic factors consists of those which related to state of individuals and their abilities regarding wound healing. Some systematic factors include infection, age and sex hormones, stress, diabetic, obesity, medication, alcoholism, smoking and nutrition and using some continuement method such as Topical wound healing (Guo and DiPietro, 2010, Ranzato, 2009, Urschel et al, 1988, Argenta and Morykwas, 1997, Kirby, 2007).The effects of some factors such as oxygenation, infection, age, stress, medication, obesity, nutrition are well described in the literature and were investigated by many enquiryers(Guo and DiPietro, 2010, Shepherd et al, 2006, Lioupis, 2005). However, using some parameters such as topical negative pressure therapy (TNPT) is new method for wound healing (Miryam et al, 1999, Kirby, 2007). Pressure is one important parameter which can influence wound healing. In one side, it can decrease the speed of healing as originate skin ulcers in some patients suffering from stroke and spinal cord injury and those who need to be in bed for a long time. In other side, it can be used to facilitate the wound healing process, especially in chronic wound (Miryam et al, 1999, Argenta and Morykwas, 1997, Evans and Land, 2001). In contrast to other usable methods, this procedure is a little bit new so the main aim of this review article was to review the relevant literature regarding TNPT and its influences on wound healing. Moreover, it was aimed to show the positive and the side effects of using this method.MethodAn electronic search was done via the Pubmed, Embase and ISI web of knowledge data from 1960 to 2010. The abstracts and titles of each individual theme were assessed by author. A first selection of relevant literature article was done based on weather the title and abstract addressed the research question of interest. Figure 1 shows the stages which were selected in this review process. The second selection of the articles was done according to the following criteriaexperiment practice published in sideaddressing using this method on wound healingFigure 1 T he stages which were selected in this research studyThe results of the various research studies were characterized based on appliance of action, the instrument used and the benefits and problems associated with the use of this method.ResultNegative pressure wound therapy (NPWT) is also known as Tropic Negative Pressure (TNP) used as a non pharmacological treatment for chronic and actuate wounds, such as pressure ulcers, diabetic wounds, abdominal and trauma wounds (Argenta and Morykwas, 1997, Evans and Land, 2001, Kirby, 2007, Miryam et al, 1999).What is NPWT?This method of treatment based on this report to turn the open wound into a close one. Moreover, it is possible to remove the excess fluid from the wound. Although, this method has been used exclusively in UK since 1995, the idea behind this method is not new. For nearly more than 50 years suction drainage has been used. It has been reported that continues suction, negative pressure drainage serve as an excellent atmospheric bandage in subcutaneous surgical procedure and help to increase the speed of wound healing. The concept was based on chemical mechanism of physics. The application of controlled subatomospheric pressure causes mechanical stress to the create from raw stuffs. The new vessels are constructed with in the tissue and the wound is drawn closed. It should be noted that the degree of pressure to the wound tissue is small, but when all areas of the wound work togheter in an efford to close toward the centre point, the effects of negative pressure become impressive and results in faster healing and resolution.This system consists of non adherent, porous wound dressing (polyurethane foam or gauze dress) and a drainage system which are attached to each others by use of a transparent film. The foam is connected to a VAC nullity pump through an evacuation tube. The suction guarantee a continues vacuum in the polyurethane foam producing a high contact zone in wound foam interface. It is requi red to change the foam every 2 days. The system is commercially available in UK since 1995 and has been used materially for wound healing. Figure 2 shows various components of this system.Figure 2 The NPWT system used for improving wound healing ( adapted from (Miryam et al, 1999) with permissionNPWT has three forms which differ based on the typecast of dress used, such as Bio Dome, gauze and foam. The polyurethane foam was used first by Morkey and Argenta in 1997. It has been reported that the foam can be easily cut according to the wound size, especially those which has a regular chassis and used when better granulation formation and wound contraction is a desirable goals. However, gauze can be used for sensitive and irregular wounds. The type of selected foam is based on the type of wound as is mentioned in table 1.The foam is placed into the defect and the area is covered with adhesive drape. The suction generate a continues vacuum in the foam, producing a high contact zone i n wound foam interface so a vacuum seal is achieved. It should be mentioned that the negative pressure applied on the wound is cxxv mm HG below ambient that is transmitted to the wound in a controlled manner. The selected pressure in this system is based on especial guidelines as shown in table 2.Wound DescriptionPoly-urethane (black foam)Polyvinyl-alcohol (soft foam)Both both mystical, acute wounds with moderate granulation tissue growthXXDeep wounds with extremely rapid growth in granulation tissueDeep pressure ulcersXSuperficial woundsXPostgraft therapyXFresh graftsXCompromised flapsXTunneling/sinus tracts/underminingXDiabetic ulcersXDry woundsXXDeep trauma woundsXSuperficial trauma woundsTable 1 The types of the foam used in NPWT systemWound Type steer Pressure Poly-urethaneTarget Pressure Polyvinyl-alcoholAcute/traumatic wound125 mm Hg125-175 mm HgSurgical wound dehiscence125 mm Hg125-175 mm HgMeshed graft75-125 mm Hg125 mm HgPressure ulcer125 mm Hg125-175 mm HgChronic ulcer (d iabetic/arterial vascular)50-75 mm Hg125-175 mm HgFresh flap125 mm Hg125-175 mm HgCompromised flap125 mm Hg125-175 mm HgTable 2 The selected negative pressure used in NPWT based on the type of foam usedEvidences regarding NPWTThere are some evidences regarding the positive effects of using NPWT on wound healing. The main advantages of this treatment method includeprovision of moist wound healing environmentremoval of the fluids and infection material which help the wound to heal speedyassisted surplusdecreased bacterial colonisationenhance formation of granulation tissuerapid cell divisionincreased blood flowincreased quash of active fibroblasts and macrophagesenhance epidermal cell formationdecreased harmful chronic wound fluidreduced the number of dressing changes and decrease revile to underlined tissueprovision of mechanical approximation of wound edgespromotion of viscoelastic flow due to tissue stretchlimitation of zone of injury after orthopaedic traumasplinting effectIndi cation and contraindication of using NPWT The foot and drug administration (FDA) approved this method for treatment of non healing wounds. Then it has been extended to include chronic, acute, and traumatic and sub acute wounds, flaps and grafts. In the United State of America the following contraindications have been considered in this regardwound with necrotic tissueuntreated osteomyelitiesfistulas to organs or body cavitiesplacement directly over exposed veins and arteriesmalignancy within woundWhat are the problems associated with NPWTThe following problems have been mentioned in the literature regarding NPWTpatients may experience discomfort or pain when the foam dressing is changedtopical skin problem may arise during usegiantism of geast or Candida infectionskin stripping and sub epidermal granulationfoam removal frequently results in trauma to wound in the form of minor capillary and granulation tissue disruptionachieving and maintaining a vacuum seal can be difficult at time sstaff mustiness be well trained and educatedDiscussionThere are over 325 publications on NPWT wound healing method, including 15 randomised clinical trials. However, it can not be concluded strongly that the system results in faster wound healing than other conventional methods or provides cost effective notwithstanding much greater material cost.It has been reported that using this method enhances bacterial clearance which improves the speed of wound healing. When microorganisms enter to wound, consume the nutrition and oxygen which other than directed toward tissue repair. When the amount of wound infection decreases (reducing bacterial loads) the healing capacity improves (the blood used for wound repairing). However, in the research undertaking by.. on 25 patients reviewed respectively, it was found that using this method dose not have any effects on bacterial clearance. Moreover, bacterial colonization increases prodigiously with this therapy and body in the range of.Impr ovement in Granulation tissue formation was other advantage mentioned in using this method for wound healing. Granulation is a small blood useless and connective tissue in the base of the wound. A well granulation wound provides an optimal bed for epidermal migration and for skin grafts as a newly formed capillary incorporate the transplanted skin. Studies have shown that granulation tissue formation is enhanced by negative pressure by virtue of interstitial fluid resolution and resulting increase in circulation.In the research done by .. on 162 patients it was shown that NPWT improves the proportion and rate of wound healing after partial foot amputation in patients with diabetics. Nearly 56% of the patients using this method achieved a comparable closure during 16 weeks assessments compared with 39% in control group. In the other research done by Blume et al (2008) the safety and clinical efficiency of this new method was compared with Advanced Moist Wound Therapy (AMWT) to treat foot ulcers in diabetic patients on 342 patients. It was found that a greater proportion of foot ulcers achieved by this method in contrast to other method (43.2% compared to 28.9%). The time of therapy was the other considered parameter in this research. The time of therapy was a little bit less in this method. Regarding the safety of the two methods there was no significant difference.Morie et al carried out a literature review based research regarding the effectiveness of this method. They mentioned that although many controlled and non randomized studies describing the effectiveness of this new method, few prospective randomized control trials have been published. They claimed that the researches in this field have lots of problems such as small sample size, variable outcome measure across studies, significant methodological problems. So it is not possible to have a strong conclusion regarding the effects of this method in contrast to other methods. They suggest that other rese arch must be done regarding the effect of this method on healing, cost of care, patient pain and quality of life in contrast to other methods.Gregor et al have undertaken another literature review regarding the effect of using this method. They also concluded that although there seems to be some evidences regarding the effects of this method on wound healing outcome as a main outcome, they are insufficient to clearly prove an additional clinical benefit of this method.Cost amity wound care is an expensive endeavour. The range of pressure ulcers which is one of the main complication of being in bed for a long time is among 2000 and 70,000 per wound. NPWT decreases the cost regarding wound healing through a decrease in the number of dressing changes required. Moreover, the supervisory role of the trained nurses would be decrease to coif dressing change. According to the results of a research the long term cost of NPWT was lower and output was better when compared with standard woun d care method. In another research study it was shown that the cost of wound healing was decreased by 38% in contrast to other method, as the healing occur by 61% faster than using gauze dressing method.ConclusionThe review of the relevant literature stated that the available evidences can not be used to determine a significant therapeutic distinction of NPWT method in contrast to other methods. There are over 325 publications on this method up to now only 15 randomized clinical trials compare the new method with other available methods.It is concluded that the available research studies can not support the effectiveness of this method on wound healing. It should be mentioned that direct comparison of NPWT to a particular type of dressing would be difficult as it is unconvincing that a single dressing type would be appropriate through out entire healing process. As there is not enough research which directly focus on the effects of this method on wound healing, and safety accordin g to wound type, the author of this article represent a need for a large high quality randomized studies. Moreover, it is recommended to evaluate the effects of this method based on the used components.