A 35-year-old woman with type 1 diabetes of 9 years' duration, no neuropathy or ischaemia, and poorly
controlled diabetes, was bitten on the lateral border of her left foot by a mosquito. The lesion was intensely pruritic and she scratched the foot. The next day she had developed swelling of the foot and cellulitis and lymphangitis spreading up the foot. She was treated with antihistamine and systemic antibiotics and the foot improved after 3 days.
' Insect bites may cause severe cutaneous reactions, leading to severe swelling and erythema of the foot • Patients should be warned to use mosquito repellent and cover up if sitting outside in summer in areas where biting or stinging insects are troublesome.
Superficial traumas to the feet are extremely common, particularly if patients walk barefoot or wear unsuitable shoes. The cause of the trauma should always be identified to prevent recurrence.
Superficial cuts or grazes may be cleaned with normal saline. Lesions should then be covered with a sterile dressing or plaster. All diabetic patients should be advised to keep a first aid box at home to treat accidental injuries.
These follow a significant trauma to the stage 1 foot, and are usually very painful and associated with severe bruising. A commonly seen fracture in patients who walk barefoot is fracture of the 5 th toe caused by catching the toe on a piece of furniture and everting the toe forcefully. Intraarticular fracture of the hallux can lead to hallux rigidus, with subsequent overloading of the plantar surface and development of callus and ulceration.
Patients in stage 1 have protective pain sensation, and fractures are treated as for non-diabetic patients. Minor fractures of a toe are usually treated by using the adjoining toe as a splint and strapping the two toes together. Metatarsal fractures may be treated in a cast or brace.
Metabolic control (Fig. 2.18)
This should follow principles of modern diabetic management. Tight control of blood glucose, blood pressure, blood cholesterol and triglycerides, as well as stopping smoking and giving antiplatelet therapy when indicated, is extremely important at stage 1 in order to preserve neurological and cardiovascular function.
Hypoglycaemia is an important metabolic complication of diabetic treatment. It is defined as blood glucose
less than 3.5 mmol/L (63 mg/dL). The incidence of hypoglycaemia is 10% per year in type 1 diabetes on twice daily insulin and 30% in those with multiple injections. There is less risk in type 2 diabetes: 0.5% per year if taking sulpho-nylureas and 2-3% in those taking insulin. All health-care professionals managing diabetic foot patients should be confident in diagnosing and treating hypoglycaemia.
The results of the Diabetes Control and Complications Trial (DCCT) and the UK Prospective Diabetes Study demonstrated the value of tight control of blood glucose with sustained decreased rates of retinopathy, nephropathy and neuropathy. Treatment regimens that reduced average HbAlc to -7% (-1% above the upper limits of normal) were associated with fewer long-term microvascular complications.
In DCCT, people with type 1 diabetes who achieved near-normal glycaemic control experienced a 69% reduction in subclinical neuropathy and a 57% reduction in clinical neuropathy, as compared with the control subjects who received the usual treatment and who had higher levels of glycaemia.
The value of tight blood glucose control in preventing macrovascular complications is not yet firmly established, but lowering HbAlc may reduce the risk of myocardial infarction and cardiovascular death.
Poorly controlled stage 1 patients may be more prone to develop sepsis than well-controlled patients.
Patients may injure their feet if they become hypoglycaemic. One of our patients damaged his feet on three separate occasions during severe hypoglycaemic episodes.
Hypertension (blood pressure greater than 140/90 mmHg) is a common comorbidity of diabetes, affecting 20-60% of people with diabetes, depending on age, obesity and ethnicity. Hypertension is also a major risk factor for cardiovascular disease and microvascular complications such as retinopathy and nephropathy. In type 1 diabetes, hypertension is often the result of underlying nephropathy. In type 2 diabetes, hypertension is likely to be present as part of the metabolic syndrome (i.e. obesity, hypergly-caemia, dyslipidaemia) that is accompanied by high rates of cardiovascular disease.
Randomized clinical trials have demonstrated the clear benefit of lowering blood pressure to below 140 mmHg systolic and 80 mmHg diastolic in people with diabetes. Thus target blood pressure should be lower than 140/80 mmHg. If the patient has microalbuminuria then the aim is for 130/80 mmHg.
Patients with diabetes have an increased prevalence of lipid abnormalities which contribute to high rates of cardiovascular disease, especially in type 2 diabetes. Lipid management aimed at lowering low-density lipoprotein (LDL) cholesterol, raising high-density liproprotein (HDL) cholesterol and lowering triglycerides has been shown to reduce macrovascular disease and mortality in patients with type 2 diabetes, particularly those who have had prior cardiovascular events. Reduction of saturated fat and cholesterol intake, weight loss and increased physical activity has been shown to improve the lipid profile in patients with diabetes.
Patients who do not achieve lipid goals with lifestyle modifications require pharmacological therapy. Statins should be used as first-line pharmacological therapy for LDL lowering. High serum triglycerides should be treated with improved glycaemic control and if this is not successful high-dose statins or fibrates.
Smoking is a very significant risk factor for peripheral vascular disease. Clear, unequivocal advice should be given to stop smoking, but it is a very difficult habit to break.
Enrolment in a smokers' clinic programme may help the patient to give up. Health-care professionals cannot afford to ignore the problem of smoking in diabetic patients and should strongly encourage them to stop. Treatment should still be offered to patients who continue to smoke, but advice to stop or reduce the amount of tobacco consumed should be frequent and unequivocal.
Diabetes may be considered as a hypercoagulable state. Daily intake of aspirin has reduced mortality in patients with diabetes and coronary artery disease. Dosages used in most clinical trials ranged from 75 to 325 mg/day. All patients with any degree of cardiovascular risk should take daily aspirin. If aspirin cannot be tolerated, then clopidogrel 75 mg daily should be prescribed.
Health-care professionals looking after diabetic foot patients should be aware of the symptoms and signs of hypoglycaemia. Capillary blood glucose measurement should be available as well as first aid treatment. A stock of glucose drink and biscuits should be available together with Hypostop Gel, glucagon and intravenous glucose.
Patients with foot problems should be aware that their treatment and investigations may be time consuming and should bring snacks or sandwiches.
Warning signs of hypoglycaemia are due to sympathetic overactivity and cerebral impairment because of reduced glucose availability.
• Paraesthesiae around the mouth
• Confusion or altered behaviour
• Slurred speech
• Loss of consciousness.
Sympathetic responses decrease with increasing duration of diabetes, and patients may become unaware that they are hypoglycaemic: they develop hypoglycaemic unawareness. It occurs in 25% of patients with type 1 diabetes and in about 50% of patients with type 1 diabetes for more than 20 years. There is a change in the glucose threshold for activation of physiological responses to low glucose. The threshold is reduced to 2.5 mmol/L (45 mg/dL) instead of 4.0 mmol/L (72 mg/dL). Warning signs develop late and the brain does not recognize them because cognitive function diminishes below 3.0 mmol/L (54 mg/dL).
Protocol for treating hypoglycaemia within the diabetic foot clinic
Non-medical reception staff should be trained to keep a close eye on patients who are waiting for treatment, and organize sandwiches, drinks or lunch as appropriate.
Reception staff should be familiar with signs and symptoms of hypoglycaemia and call a health-care professional if they suspect hypoglycaemia.
If the patient reports symptoms of hypoglycaemia or staff suspect hypoglycaemia:
• A capillary blood glucose should be measured
• If below 3.5 mmol/L (63 mg/dL), hypoglycaemia is confirmed
• If the patient is not drowsy and can swallow, give 130 mL Lucozade or 200 mL fresh orange juice
• On recovery give 20 g of starchy carbohydrate such as a slice of bread or two digestive biscuits
• If patient cannot swallow, give Hypostop Gel around gums or glucagon 1 mg intramuscularly
• Check capillary blood glucose again after 15 min
• Give another glass of Lucozade if blood glucose is still below 3.5 mmol/L (63 mg/dL)
• If very drowsy give 75 mL of 20% glucose intravenously into a large vein through a large-gauge needle or give 1 mg glucagon intramuscularly
• Patient should not be left alone
• Check blood glucose again before they go home. If the patient has become hypoglycaemic from sulphonylurea therapy he should be admitted for at least 24 h and may need intravenous glucose therapy (5-20% as required)
• Give advice on hypoglycaemia prevention.
Practical care of the stage 1 foot should involve a considerable amount of patient self-management education. All diabetic patients need to know, as an absolute minimum:
• What constitutes good foot care
• What is suitable footwear
• What to do and where to go if they develop a foot problem
• Simple first aid self-treatment
• The importance of the annual review examination. There are different modes of communication in the education of patients. These include one-to-one discussion during the foot treatment, group discussions and distribution of written material. It is also possible to ask patients to advise and help other patients. Different patients respond to different modalities and different approaches: there is no one correct way of approaching education.
It is never too early to teach patients good foot care and footwear habits, and address barriers to care in order to gain long-term improvements in outcomes. However newly diagnosed patients may feel overwhelmed and inundated with information. For this reason, it may be best to delay foot care and footwear education for a few weeks, until the patient is feeling less upset and confused, and has digested the myriad of other information he has been given. However, the feet should always be checked at diagnosis since some type 2 patients, undiagnosed for some time, may already have diabetic foot problems. Diabetes foot care education should always be individualized and tailored according to a specific patient's needs, lifestyle and psyche, and frequently adapted as necessary. Explanations should be given as to the reasons for requests made to the patient to adapt his lifestyle. It is cruel to tell a young, fashion-conscious diabetic patient that she should spend the rest of her life in lace-up shoes, or the parents of a small diabetic child that he should never go barefoot. As in all areas of diabetes education, compromises sometimes have to be agreed upon. Advice should be practical and relevant to the patient's lifestyle. However, if the patient's behaviour is likely to lead to future problems he should be told.
Patients with a history of severe diabetic complications in near relatives, some of whom may have lost a limb, may be particularly vulnerable, both because of genetic factors and because of fear and loss of hope which makes them deny the efficacy of preventive treatment and fail to appreciate the long-term rewards of good control and foot care. These patients need extra support and education. For some patients the complications of diabetes seem unavoidable. They believe that no matter what they do, the outcome will be the same—amputation. This hopeless attitude needs to be corrected by education.
The approach must always be flexible. Some patients want a lot of information in order to feel safe: others will 'switch off' if given more than very simple basic information. Verbal education should be issued in small 'digestible' chunks, and reinforced by written material, including diagrams and pictures. Some patients will wish to have quite extensive information about the foot in diabetes and these stage 1 patients can be taught about neuropathy and ischaemia, the implications of these conditions, the ways in which their onset can be delayed or prevented and the terminology used to describe diabetic foot problems. Verbal education should be reinforced with written education and vice versa.
If group education sessions are held, the patients' families should be invited to attend and everybody should be taught how to check the feet. Group education may help lonely or isolated people with diabetes, especially the newly diagnosed. We also ask patients to remove their shoes at education group sessions.
Some clinics have used patients as educators and we have found this approach helpful. Reformed reprobates can have great insight into barriers to care! Some of our patients have worked as volunteers, giving advice and encouragement to other patients. We also find that our 'open plan' clinic, where individual treatment areas are not walled or curtained off, enables patients and healthcare professionals to learn from each other.
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