Pathogenesis of Formation of Neuropathic Ulcers - Case Study Example

The purpose of this case study is to describe a case of a foot ulcer secondary to a diabetic neuropathy. The study will aim to provide basic background knowledge about diabetes mellitus, its types, incidence, clinical features and commonly encountered complications. It will then discuss the pathogenesis of formation of neuropathic ulcers in diabetes mellitus. In light of the case of the patient under study, the short and long term management of such a case will then be focused on. In the end, the various techniques used in the management of this condition will be assessed and their efficacy analyzed. The patient Mr. X is a 78 year old, retired electrician. He presented with complaints of a painless ulcer on the heel of the right foot for the last 2 weeks. He had not noticed the ulcer before this. There were no complaints of a discharge from the ulcer and it did not appear to have increased in size during this time. The patient was a smoker but quit in 2007. He is a moderately heavy drinker consuming up to 2 pints per week. His medical history is significant for the presence of macrovascular complications including hypertension( for which the patient was put on beta blocking agent, atenolol for the last 5 years), high cholesterol(for which he is on HMG-CoA reductase inhibitor, simvastatin for the last 2 years) and angina pectoris for which he is taking vasodilator glycerol trinitate for 2 years. He is also a diagnosed case of type two diabetes, being treated with metformin 500 mg bd and gliclazide 40 mg bd for the last 10 years. On local examination, an ulcer 5mm by 7 mm in size was seen on the medial aspect of the right calcaneum. It had smooth margins, giving it a characteristic punched out appearance,. The base of the ulcer was pink, and there was no erythema or discoloration in the surrounding skin. There was no evidence of granulation in the base of the ulcer. The surrounding skin was indurated and dry. The foot was slightly cooler than the left one. The dorsalis pedis and posterior tibial were palpable. On examination using a 10g monofilament, patchy loss of sensation was detected all over the right foot(most sensitive test available in the clinical setting[McNeely & Boyko, 1995]). Also the vibration sense, as determined using a tuning fork was found to be impaired. There was no other significant findings except the presence of varicosities on the calf in the small saphenous system. The patients foot wear was examined and found to be wide toed lace up boots with good heel and arch support. Diabetes mellitus is a syndrome of chronic hyperglycemia due to relative insulin deficiency, resistance or both. It affects more than 120 million people worldwide it is estimated that it will affect 220 million by the year 2020.(Kumar & Clarke, 2005). The cases can be classified into two broad types: type 1 is juvenile onset diabetes mellitus and is characterized by decreased production of insulin by the beta cells of the islets of Langerhans. It is treated by dietary management or regular administration of exogenous insulin. (Longmore, Wilson & Rajagopalan,2005). Type 2 is adult onset diabetes and is characterized by end organ resistance to insulin. It is treated with dietary management, weight loss, oral sulfonylureas, metformin, acarbose and glitazones. ( Longmore, Wilson & Rajagopalan, 2005). The complications of diabetes mellitus can be classified as microvascular and macrovascular. Among the macrovascular complications is the association of diabetes with an increased incidence of coronary artery disease, strokes and peripheral vascular disease. Prominent among the microvascular complications of diabetes are autonomic neuropathy, diabetic retinopathy, diabetic nephropathy, diabetic neuropathy and foot disease, i.e. ulceration and arthropathy. ( Davidson, 2006) In diabetic patients, feet are very susceptible to injury and special care needs to be taken of them. A large study carried out on almost 9000 diabetic patients in 1999 showed a cumulative incidence of almost 6% for forming foot ulcers(Ramsey, Newton & Blough, 1999). The annual incidence for formation of diabetic ulcers is in the order of 2-3% for patients with type 1 and type 2 diabetes and 46% of all hospital admissions due to ulcerations are due to diabetic ulcers(Fryckberg, 1999). The lifetime incidence of ulcers in diabetic patients is in the order of 25%(Singh, Armstrong and Lipsky, 2005). The interplay of a number of factors is involved in the formation of diabetic ulcers. As a result of the autonomic neuropathy in diabetic patients, local vasomotor reflexes are lost. Sweating does not take place and the resulting dry skin is susceptible to the formation of fissures. As a consequence of the somatic neuropathy, perception of pain is reduced as a result of which a patient may remain unaware of a tight shoe or a pressure point that over the period of time may create an un-healing ulcer. Peripheral vascular disease also contributes to the overall picture by decreasing the supply of blood available to the feet and thus causing poor healing.(McPhee, Papadakis & Tierney, 2008). Upto 90 % of all diabetic ulcers do heal when treated with a comprehensive approach that includes techniques for relieving weight from the ulcerated area, treatment of infection, and restoration of arterial perfusion (Caputo & Cavanagh, 1994). Management of diabetic foot ulcers is carried out at three levels. At the level of primary prevention it is necessary that all diabetic patients are taught the importance of foot care at the time of initial diagnosis. My patient had been provided this information by his primary physician and was meticulous in his choice of foot wear. The information booklet for the American Diabetes association says that the following information should be provided to patients regarding foot care( 2009): “Wash your feet every day with lukewarm (not hot) water and mild soap. Dry your feet well, especially between the toes. Use a soft towel and pat gently; dont rub. Keep the skin of your feet smooth by applying a cream or lanolin lotion, especially on the heels. If the skin is cracked, talk to your doctor about how to treat it. Keep your feet dry by dusting them with nonmedicated powder before putting on shoes, socks or stockings. Check your feet every day. You may need a mirror to look at the bottoms of your feet. Call your doctor if you have redness, swelling, pain that doesnt go away, numbness or tingling in any part of your foot. Dont treat calluses, corns or bunions without talking to your doctor first. Cut toenails straight across to avoid ingrown toenails. It might help to soak your toenails in warm water to soften them before you cut them. File the edges of your toenails carefully. Dont let your feet get too hot or too cold. Dont go barefoot.” At the time of presentation, the patient was immediately referred to a podiatrist for the removal of the callus. In the absence of any erythema, the presence of an infection appeared unlikely and thus antibiotics were not prescribed. A light weight plaster was used to offload pressure from the affected area while keeping the patient mobile and thus accelerating healing.( Warrel, Cox and Firth. 2003). Early treatment is essential to decrease the morbidity of diabetic ulcers. A study shows that every year 82000 limb amputations are performed due to diabetes and that a decrease in this number can be achieved through adherence to the following protocol: “(1) measurement of the wound by planimetry; (2) optimal glucose control; (3) surgical debridement of all hyperkeratotic, infected, and nonviable tissue; (4) systemic antibiotics for deep infection, drainage, and cellulitis; (5) offloading; (6) moist-wound environment; and (7) treatment with growth factors and/or cellular therapy if the wound is not healing after 2 weeks .”(Brem, Sheehan and Bolton, 2004). Underlying osteomyelitis should be ruled out because a study published in 1991 showed the presence of subclinical osteomyelitis in 68 % of all diabetic foot ulcers. (Newman & Waller, 1991). Among long term measures the importance of glycemic control in preventing the recurrence of such ulcers was stressed upon.( Akbar & Bilal, 2004) A regular follow up was ensured so that any developing problems or the development of chronic ulcers could be recognized early. One month later when the ulcer was still found unhealed the patient was given a choice between two experimental treatments are now being introduced to induce rapid healing in diabetic ulcers. One study showed that once daily application of topical recombinant human platelet derived growth factor promotes the rapid healing of chronic diabetic ulcers without inducing any significant adverse effects. (Steed, 1995). ). Another new experimental technique that has been introduced is hyperbaric oxygen (HBO) therapy. Daily sessions of oxygen breathing at 2.5-bar increased pressure in a hyperbaric chamber, has beneficial actions on wound healing including antimicrobial action, prevention of edema and stimulation of fibroblasts. (Kalani 2005). The patient had concerns about the possible need for amputation. It was explained that this would in all probability be unnecessary. Overall the least cost effective measure in diabetic foot treatment has been found to be amputation. Apelqvist and Larsen believe that a multidisciplinary approach including preventive strategy, patient and staff education, and multifactorial treatment of foot ulcers would reduce the amputation rate by more than 50%. (2000). The patient chose to continue with conservative treatment and regular dressing change with debridement when necessary. After 4 weeks the ulcer was found to be granulating well. Fears that as those related to amputation need to be assuaged because they lead to depression and depressive symptoms have been shown to be related with poor healing and recurrence of diabetic ulcers. (Monami & Longo,2008). Increased foot pressure is a recognized cause of formation of diabetic foot ulcers(Veves, Murray & Young, 1992) In the case of our patient who is retired however, this is not a valid consideration. The economic considerations involved in a chronic problem of this type should also be taken into account. A recent study showed a lack of financial benefit when comparing primary amputation with limb salvage approach. (Rieber, Libsky & Gibbons,1998). References 1. Akbar, Nighat. Bilal, Nighat. 2004. “THE SWEET FOOT Relation of Glycemic Control with Diabetic Foot Lesions.” International Journal of Pathology; 2004; 2(2):90-93 2. Apelqvist, J. Larsson, J. “What is the most effective way to reduce incidence of amputation in the diabetic foot?” 2000. Diabetes metabolism Research and Reviews. Volujme 16. 3. Brem, H. Sheehan, P. Bolton, A. Protocol for treatment of diabetic foot ulcers*1 The American Journal of Surgery, Volume 187, Issue 5, Pages S1-S10 4. Caputo, Gregory. Cavanagh, Peter. 1994. “Assessment and Management of Foot Disease in Patients with Diabetes”. The new England journal pf medicine. Volume 331. 5. Davidson, Stanley. Pg 828. 2006. Principles and Practice of Medicine. Ed 19. EL SEVIER. 6. Fryckburg, Roberts. 1999. “ Epidemiology of Diabetic Foot.” 7. Information booklet for American diabetes association. 8. Kalani, M.2002. “Hyperbaric oxygen (HBO) therapy in treatment of diabetic foot ulcers Long-term follow-up.” Journal of Diabetes and its Complications, Volume 16, Issue 2, Pages 153-158 9. Kumar, Parveen and Clark, Michael. Pg 1101. 2005. Clinical medicine. Ed 6. EL SEVIER. 10. Longmore, Murray. Wilkinson, Ian. Rajagopalan, Supraj. Pg. 294. 2005. Oxford Handbook of Clinical Medicine. Ed 6. OXFORD. 11. McPhee, Stephen. Papadakis, Maxine. Tierney, Lawrence. Current Medical Diagnosis and Treatment. 2008. LANGE. 12. McNeely, M. Boyko, E. 1995. “The independent contributions of diabetic neuropathy and vasculopathy in foot ulceration. How great are the risks?” Journal of American Diabetes association. Volume 18. 13. Monami, Matteo. Longo, Rosella. 2008. “The Diabetic Person Beyond a Foot Ulcer: Healing, Recurrence, and Depressive Symptoms”. Journal of the American Podiatric Medical Association Volume 98 Number 2 130-136 2008 14. Newman, Lisa. Waller, John. “ Unsuspected Osteomyelitis in Diabatic Foot Ulcers.” 1991. Pg 1246. JAMA. 15. Rieber, G. Lipsky, B. Gibbons, G. “The burden of diabetic foot ulcers.” The American Journal of Surgery, Volume 176, Issue 2, Pages 5S-10S 16. Ramsey, Scott. Newton, Katherine. Blough, David. 1999. “Incidence , Outcomes and Cost of Foot Ulcers in Diabetes.” 17. Singh, Nalini. Armstrong, David. Lipsky, Benjamin. 2005. “Preventing Foot Ulcers in Patients with Diabetes.” JAMA. VOL 293. 18. Steed, D. Clinical evaluation of recombinant human platelet – derived growth factor for the treatment of lower extremity diabetic ulcers Journal of Vascular Surgery, Volume 21, Issue 1, Pages 71-81. 19. Veves, A. Murray, H. Young, M. 1992. “The risk of foot ulceration in diabetic patients with high foot pressure: a prospective study.” Diabetologia. Volume 35. number 7. 20. Warrel, David. Cox, Timothy. Firth, John. 2003. Oxford Textbook of Medicine. 4 edition. OXFORD. Read More