Importance of Ankle Brachial Pressure Index (ABPI)

Ankle Brachial Pressure Index test use as a tool of foot assessment in diabetic patient to reduce rate of lower extremity amputation.

INTRODUCTION

This essay will reflect on the importance of ankle brachial pressure index (ABPI) use as a tool while performing foot assessment (FA) to identify diabetic patients who are at risk of foot ulcers and detecting vascular impairment in diabetic foot ulcers (DFU) hence preventing lower extremity amputation (LEA). FA helps to detect the level of risk of a diabetic patient developing a foot ulcer (Singh N et al., 2005, Grawford F et al.,2007). When there is no early detection and intervention, foot ulcers deteriorate resulting in amputation of the affected limb (Kerr M, 2012, Young MJ et al., 2008). All diabetic patients should perform annual FA to identify any abnormality (American Diabetes Associaton 2012) and those who are at risk should have FA done more frequently (Frykberg RG et al., 2006).

Gibbs’ model of reflection (Gibbs 1988) is used in this discussion because it is easy to use, simple and is a good guidance of reflection.

25% of diabetic people will develop foot ulcer due to diabetes (Singh N et al., 2005) while 85% of diabetic patients with foot ulcers can lead to LEA (Pecoraro RE et al., 1990, Margolis DJ et al., 2005). “The emotional and financial costs of diabetic foot disease are high” (Close-Tweedie, 2002). Approximately 400 cases of LEA are performed yearly in Mauritius due to complication of Diabetes, costing about Rs 50,000 to Rs 100,000 for each limb amputation (Apsa International 2014, Mauritius Research Council 2012).

However 85% of level of amputation can be reduced through a multidisciplinary team by early detection of foot problems, proper FA, empowering patient by giving them health education, close monitoring and proper care (International Diabetes Federation 2005, Pecoraro RE, 1990).

DESCRIPTION

The Government of Mauritius is doing much effort to increase the quality of life of diabetic people, national digital retinal screening service and podiatry services are available (Millenium Development Goals Status Report 2013). Foot ulcer clinics have been set up in all regional hospitals in Mauritius. During my training as a foot ulcer nurse I happened to do an ABPI (see Appendix 1) while doing FA with a patient whom I will call Mr John who has a non healing ulcer in his left hallux. His foot has never been assessed by a health care professional and he was not aware of FA. The ABPI result was 0.7 (see Appendix 2) indicating that he has moderate peripheral arterial disease. He was referred to the vascular surgeon by the treating Doctor. The result was confirmed through a colour duplex Doppler showing significant and arterial stenosis below the knee by greater than 60%. The patient underwent revascularization. Proper management of the wound was done, compression was not applied (Vowden K and Vowden P, 2002) and now the ulcer is showing good signs of healing.

FEELINGS

Getting the opportunity to follow the foot ulcer management course made me overwhelm. I was so enthusiastic to learn new ways and techniques of FA that I will apply with patients acting as a barrier to protect them from stumbling into the pitfall of foot complications hence preventing amputations. Before undertaking the module I was not aware of the importance of FA in preventing LEA. A 10g Semmes Weinstein monofilament is used to check loss of sensation in neuropathy and a hand-held doppler use to calculate ABPI to assess the vascular flow was far from my know how. After undertaking the module and wider reading with endeavours, though there were many ups and downs due to time constraint, now I feel more self-confident and have more expertise in practicing ABPI while doing FA. Having been able to detect the cause of non healing ulcer of Mr John through an ABPI while doing FA, I felt very happy and eventually this has motivated me to learn the module more correctly. I was determined to put ABPI technique into practice in my field of work so that I can manage patient correctly and refer them to the appropriate channel for specific treatment through multidisciplinary team (John Ovretveti, 1996).

EVALUATION

I have learnt that foot problems related to diabetes occur very quickly, causing rapid tissue breakdown which is often complicated by infection (Edmonds et al., 1986) and eventually may lead to LEA (Close-Tweedie J, 2002). Factors influencing wound healing are hyperglycaemia (McInnes, 2001), change in metabolism of carbohydrates, fats and proteins because of insulin deficiency (Cooper, 1990). Furthermore many factors prevent the normal process of wound healing at cellular level including delayed closure, contraction retarded due to delayed myofibroblast phenotype, granulocytes effect, no collagen synthesis, chemotaxis defects and no growth factors (Close-Tweedie J, 2002). Therefore, if there is decrease in tissue perfusion and oxygenation, wound healing will not take place (Terranova, 1991). Peripheral Arterial Disease (PAD) in the lower extremity is a condition where there is narrowing of arteries in the legs and feet due to accumulation of fatty substance called plaque, inside the walls of arteries. This result in poor blood supply to the muscles and tissues in the legs and feet hereby causing pain, tissue death and even gangrene.

It is important to assess the arterial perfusion as impaired circulation contribute to non healing ulcer (Akbari CM, 2003). When assessing diabetic foot, the palpation of ankle pulses should not be used alone to detect arterial disease (Vowden K and Vowden P, 2002) and “distal perfusion can only be accurately assessed by the correct application of Doppler” (Whiteley et al., 1998). The ABPI is a simple, quick, non-invasive tool use to identify PAD(Bhasin N and Scott DJA, 2007). However, ABPI is not as easy to perform as it appears.

I have done an ABPI with Mr John and this has helped in identifying the cause of the non healing ulcer. This was due to impaired blood circulation and the patient has been directed to the proper pathway to restore the blood flow. Hence this has helped the wound to show good signs of healing.

ANALYSIS

It is through performing an ABPI with Mr Brown that the cause of the non healing wound has been detected. I am pondering on how many patients have non healing ulcers due to impaired circulation and FA has not been done including ABPI.

So ABPI is done on all diabetic patients with or without foot ulcers who are coming to our clinic for FA and they are being referred to proper channel for further management. My aim is to prevent diabetic patients to have foot complications and reduce the rate of LEA. ABPI result help us to evaluate the vascular supply, level of ischaemia, level of pain in the leg, determine the prognosis for patients having vascular disease and guide whether the patient should undergo revascularization or do angioplasty, stenting or bypass surgery of lower extremity. (Grenon SM et al., 2009). By interpreting the ABPI resuIts, now I am sure and certain of what types of bandaging to use, what dressing materials and medications to use to treat and help healing of ulcers. ABPI also guides us to decide whether debridement of the wound should be done or not and what type of offloading techniques to be implemented.

CONCLUSION

The fundamentals basics for healing of DFU are good perfusion, debridement, infection control, and pressure mitigation. To obtain successful outcome in the management of DFU is to recognize the etiological factors (Wu SC et al., 2007). Doing an ABPI help to improve the management of diabetic patients. The ABPI assessment was of great help to know the risk of the foot. For those having no ulcers, they are being managed by the correct channel to prevent complications from arising, while those having an ulcer are also diverted to correct pathway of treatment including surgeons and foot care nurses to manage foot problems correctly under the guidance of all expertise available at the hospital level.

ACTION PLAN

Now having well grasped the module workbook, I have allocated myself with a good time of reflection about how previously diabetic patients, with or without ulcers, were being treated and what was the complication and drawbacks we had in our system. After I have well understood the importance of ABPI during my studentship at the module and from my personal experience gained during the management of diabetic foot ulcer, now I make it a must that all diabetic patients, attending hospital from any sections, have an appointment to screen their foot with an ABPI done. Eventually, canalizing them through the correct pathways for further investigations and management required with the goal to reduce the rate of LEA.

However, ABPI is contraindicated when there is excruciating pain in the leg or foot, in the presence of deep venous thrombosis as the thrombus may be dislodged and in patient with renal failure doing dialysis. ABPI results should be interpreted with care in patients having heavily calcified or incompressible vessels, where they may be misleadingly high. (Grenon SM et al., 2009).

REFLECTION

In this work piece of reflection, I have demonstrated how I use ABPI on diabetic patients to reduce the rate of LEA. Observing the result being achieved by this assessment, other members of health care providers insist about the implementation of this typical assessment. We are now more eager to know about the ABPI result on diabetic patients prior moving forward with any kind of management. I feel happy that my knowledge gained from the module are being put into practice and ABPI assessment has proved to be a great tool to reduce LEA which has been the aim of the government since long.

REFERENCES

Akbari CM, Macsata R, Smith BM, Sidawy AN. Overview of the diabetic foot. Semin Vasc Surg 16:3-11, 2003.

American Diabetes Association. Standards of Medical Care in Diabetes-2012. Diabetes Care, Volume 35, Supplement 1, January 2012.

Apsa.mu, (2014). Foot Care Clinic | Apsa International. [online] Available at: http://apsa.mu/services/foot-care-clinic/ [Accessed 22 June 2014].

Bhasin N and Scott DJA. Ankle Brachial Pressure Index: identifying cardiovascular risk and improving diagnostic accuracy. JR Soc Med. Jan 2007; 100(1): 4–5. [online] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1761677/ [Accessed 22 June 2014].

Close-Tweedie J. Diabetic foot wounds and wound healing: a review. Diabetic Foot Vol 5, No 2, 2002.

Cooper DM (1990). Optimising wound repair: a practice within nursing’s domain. Nursing clinics of North America 25(1): 165-80.

Department of Health, 2001. National Service Framework for Diabetes:Standards. [online] Available at http://www.gov.uk/government/uploads/attachment_data/file/198836/National_Service_Framework_for_Diabetes.pdf [Accessed 04 June 2014].

Edmonds ME, Blundell MP, Morris HE et al (1986). The diabetic foot: impact of a foot clinic. The Quarterly Journal of Medicine 232: 763-71.

Frykberg RG, Zgonis T, Armstrong DG, Driver VR, Giurini JM, Kravitz SR, Landsman AS, Lavery LA, Moore JC, Schuberth JM, Wukcih DK, Andersen C, Vanore JV: Diabetic Foot Disorders : a clinical practice guideline (2006 revision). J Foot Ankle Surgery 45 (Suppl 5): S1-S66, 2006.

Gibbs G, 1988. Learning by Doing: A Guide to Teaching and Learning Methods. Oxford: Oxford Further Education Unit (online) Available at: https://www.brookes.ac.uk/services/upgrade/study-skills/reflective-gibbs.html [Accessed 17 June 2014].

Grawford F, Inkstor M, Kleijnen J, Fatey T. Predicting foot ulcers in patients with diabetes: A systematic review and meta-analysis. QJ Med 2007; 100(2): 65-86.

Grenon S. Marlene, Gagnon Joel and Hsiang York. Ankle-Brachial Index for Assessment of Peripheral Arterial Disease. The New England Journal of Medicine 2009; 361: e40/ November 2009. [online] Available at: www.nejm.org/doi/full/10.1056/NEJMvcm0807012 [ Accessed 22 June 2014].

International Diabetes Federation (2005) Clinical Guidelines Task Force; Global guidance for Type 2 Diabetes. Brussels.

International Working Group on the Diabetic Foot, 2011. [online] Available at: www.iwgdf.org [Accessed 18 June 2014].

Kerr M. Foot care for people with diabetes: the economic case for change. NHS Diabetes, Newcastle-upon-Tyne, 2012.

Margolis DJ, Allen-Taylor L, Hoffstad O, Berlin JA. Diabetic neuropathic foot ulcers and amputation. Wound Repair Regen 13:230-236,2005.

Mauritius Research Council, Ebene. Impact of food quality on human health, Feb 2012. [online] Available at: http://www.mrc.org.mu/document2012/nationalgroup/Impacts%20of%20Food%20Quality%20on%20Human%20Health.pdf [Accessed 21 June 2014].

McInnes A (2001). Guide to the assessment and management of diabetic foot wounds. The Diabetic Foot 4 (Suppl 1):S1-11.

Millennium Development Goals Status Report 2013, Government of the Republic of Mauritius. [online] Available at http://www.undg.org/docs/13330/Muaritius-MDG-Status-Report-2013.pdf [Accessed 21 June 2014].

Ovretvet John. Five ways to describe a multidisciplinary team. Journal of Interprofessional care, vol 40, no 2, 1996.

Pecoraro RE, Reiber GE, Burgess EM. Pathways to diabetic limb amputation. Basis for prevention. Diabetes Care, 1990; 13(5): 513-21.

Singh N, Armstrong DG, Lipsky BA: Preventing foot ulcers in patients with diabetes. JAMA 293: 217-228, 2005. [online] Available at: www.ncbi.nlm.nih.gov/pubmed/15644549 [Accessed 02 June 2014].

Vowden Kathryn and Vowden Peter. Hand-held Doppler Ultrasound: The assessment of lower limb arterial and venous disease. Huntleigh Healthcare 2002. [online] Available at: www.huntleigh-diagnostics.com. [Accessed 21 June 2014].

Terranova A (1991). The effects of diabetes mellitus in wound healing. Plastic Surgical Nursing 11: 20-5.

Whiteley MS, Fox AD and Horrocks M (1998). Photoplethysmography can replace hand-held Doppler in the measurement of ankle/brachial indices. Ann R Colll Surg Engl 80 (2): 96-98.
Wu Stephanie C, Driver Vickie R, Wrobel James SandDavid G Armstrong David G. Foot ulcers in the diabetic patient, prevention and treatment. Vascular Health and Risk Management Feb 2007; 3(1): 65–76.
Young MJ, McCardle JE, Randlall LE, et al. Improved survival of diabetic foot ulcer patint’s 1995-2008: possible impact of aggressive cardiovascular risk management. Diabetes Care 2008; 31: 2143-47.

APPENDIX 1 – Procedure of performing ABPI by Huntleigh Healthcare 2002

Patient is reassured and procedure is explained. Make sure patient is in supine position, comfortable, relaxed with sufficient rest.

• An appropriate sized cuff is placed around the upper arm and the brachial systolic blood pressure is measured.

• The equipment and the arm should be at heart level.

• When the brachial pulse is felt, ultrasound contact gel is applied.

• The probe of the Doppler should be at an angle of 45 degree and is moved till the best signal is obtained.

• The cuff is inflated until the signal disappeared, then is deflated slowly so that the probe is not moved from the line of the artery and at the point where the signal returns, the pressure is recorded.

• The procedure is repeated in the other arm.

• The highest of the two values of systolic pressure is used for the ABPI calculation.

• The systolic pressure of the ankle is taken by placing an appropriate sized cuff around the ankle immediately above the malleoli. The equipment should be at heart level. If any ulcer is present, it should be protected with a plastic film.

• The dorsalis pedis pulse is felt and contact gel is applied. The cuff is inflated until the signal disappear, then is deflated slowly and ensure the probe is not moved from the line of the artery and at the point where the signal returns, the pressure is recorded.

• The procedure is repeated for the posterior tibial.

• The highest systolic pressure reading is used to calculate the ABPI for that leg.

• Same procedure is applied in the other leg.

• The ABPI is calculated for each leg using the formula below.

ABPI = Highest systolic pressure recorded at the ankle of dorsalis pedis and posterior tibial for that leg divided by the highest systolic brachial pressure of right and left arm.

APPENDIX 2 – Reading of ABPI by Huntleigh Healthcare 2002

ABPI > 1.0 to 1.4 is considered as normal

ABPI < 0.92 indicates arterial disease

ABPI > 0.5 and < 0.9 can be associated with claudication and patient is referred for further assessment

ABPI <0.5 indicates severe arterial disease and patient is referred immediately for a vascular opinion.

ABPI >1.4 indicates calcification

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