Key learning points:
– Diabetic foot syndrome is a series condition that requires prompt referral
– Effective care saves limbs and the lives of people with diabetes
– NICE NG19 offers guidance for effective care for people with diabetic foot syndrome
Diabetes is reaching epidemic levels and the International Diabetes Federation1 recently stated that 415 million people aged 20-79 across the world are now known to have the condition. It is further speculated that this is due to increase to more than 642 billion by 2040. This is exceptionally concerning as we know that in the UK we have over four million people already diagnosed,2 with 10 million people considered to be at high-risk of type 2 diabetes or already living with non-diabetic hyperglycaemia.2 This places these individuals at increased risk of foot disease, especially at diagnosis3 if intervention prevention strategies are not in place.3,4,5
One person tragically dies from a diabetes-related avertable complication every seven seconds across the world, with foot complications including neuropathy and peripheral vascular disease presenting major preventable health challenges.4 This article will investigate how foot problems occur in people with diabetes. It will particularly look at how practitioners can work in partnership with people to avoid preventable amputation by expediting assessment and prompt referral to a multidisciplinary footcare team, in accordance with new National Institute for Health and Care Excellence (NICE) guidance.6
Risk of amputation in diabetes
The lifetime risk of someone with diabetes developing a foot ulcer is suggested to be 25%,3,5 and a further 85% of amputations are preceded by the presence of foot ulceration. In the UK, approximately 135 leg, foot and toe amputations take place on people with diabetes each week. Across the world this equates to an amputation caused by diabetes occurring every 20-30 seconds.3,4 Intrestingly, 80-85% of all amputations caused by diabetes are largely preventable.3,5 People with diabetes are nine times more likely to experience a minor amputation and five times more likely to undergo a major amputation than counterparts without diabetes.7 Diabetes UK8 suggested that four out of five amputations in the UK are entirely preventable if more proactive care and a prompt referral to specialist teams had been in place.
Life expectancy is greatly affected. It is estimated that 80% of people die within five years of having an amputation for diabetes related vascular or neuropathic ulceration.9
Mortality is greater for people with diabetes related foot disease than for people experiencing either colon, breast or prostatic cancers.7 Despite this, diabetes and diabetes-related foot syndrome does not carry the same emotive response in the general public than a diagnosis of cancer generates.5
How does diabetic foot syndrome occur?
The start of diabetic foot syndrome (DFS) is defined as ‘ulceration of the foot, distally from the ankle (and including the ankle) associated with neuropathy, ischaemia and infection’.10 Diabetic foot syndrome includes a number of pathologies which include neuropathy, peripheral vascular disease, charcot neuroarthropathy, foot ulceration and osteomyelitis.11
Diabetic foot syndrome is multifactorial and complex including peripheral neuropathy – which is frequently the first trigger, as a loss of protective sensation is experienced. Foot deformity including toe clawing, possible trauma from stepping on sharp objections and abnormal foot pressures can cause chafing and trauma through ill-filling shoes.5 Abnormal joint mobility can cause altered pressure points.4
Altered proprioception (the ability to judge where your foot will land when walking), due to somatic neuropathy (damage to the peripheral nervous system) causes insensitivity and small muscle wasting in the sub-tablar and mid-foot joints. This in turn causes altered loading under the foot when walking or standing.3,5 This triggers ulceration due to high pressures being applied in areas of the foot. People experiencing this are at further increased risk due to experiencing peripheral autonomic dysfunction (where the autonomic nervous system does not function properly to send messages to the brain), which when occurring without peripheral vascular disease, results in increased resting blood flow in the foot. This causes warm but insensitive feet, which are high risk, especially as dry skin which unless moisturised daily will crack and fissure. Therefore, community nurses can advise people in their care to wash, dry and moisturise their feet daily to keep skin healthy. Repeated pressure on areas of high risk in the foot causes callus formation on weight-bearing areas. So, primary care nurses can help people to understand that they need to move their feet and legs to avoid undue pressure, especially from ill-fitting shoes which can cause callus and skin breakage. Presence of callus is indicative of ulcer formation3,5,12 thereby this needs prompt referral to the local foot protection team.6
The start of DFS is the loss of the protective sensory sensation, which offers people ‘an alarm to action’ in situations of trauma or injury. When blood glucose, blood pressure and cholesterol levels are high for a prolonged period of time this can lead to damage occurring to the nerve cells throughout the body and the majority of damage occurs distally in the feet. Being taller increases risk as the length of the distal nerves are longer,4 thereby the most common areas affected are the extremities. Damage occurring to the feet is peripheral neuropathy which can lead to pain and/or tingling but most commonly leads to loss of sensation. If the person affected treds on something sharp which damages the foot or pierces the skin, the person will not detect the injury as they cannot feel the impact. Therefore nurses should tell patients to always wear shoes when walking, even in the house, and to inspect their feet daily for signs of damage or injury that they might not have felt. The development of a wound with no action from the individual – who is unaware – leads to infection and destruction of deeper tissues, possibly including the bone and causing osteomyelitis which is infection in the bone – and requires emergency referral for treatment to hospital.9
If impaired, peripheral circulation is also present, the sub-optimal blood supply to bring oxygen to the wound and remove toxins can cause further deterioration and ulceration in these circumstances which can escalate rapidly and can necessitate a minor ulcer becoming a major ulcerated area requiring major amputation.4,12
Peripheral vascular disease can further result in ischaemia occurring. This is evident through reduced blood flow to the lower limbs and intermittent claudication, pain on exertion, pain at rest, critical limb ischaemia and possible gangrene.5 Peripheral vascular disease is accelerated by smoking, hypertension, hyperglycaemia, hyperlipidaemia – all cardiovascular risk factors. Thereby offering smoking cessation advice as required and signposting people to help stop smoking can pay huge dividends in terms of health protection and wound healing. Peripheral vascular disease is more common in people with diabetes, however ischaemic ulcers probably present only about 10% of all ulceration, as 90% are usually caused by neuropathy alone, or combined with ischaemia.4
In the UK, neuro-ischaemic ulcers are the most common present type of ulcer, with infection in at least 58% of all ulcers.4 Infection is not a primary cause of foot ulceration, but a secondary cause, following an injury or ulceration to the protective epidermis.11 Infection triggers the increased need for hospitalisation, with 50% of people affected requiring amputation as a result of the infection, 16% requiring a transtibial amputation, with the median length of inpatient stay being eight days.13 Foot infections have a profoundly negative affect on the individual, and impacts their quality of life, physical and mental wellbeing and lower extremity function.11
How to avoid amputation in people with diabetes
Education for patients with diabetes to inspect their feet daily and seek help promptly should be a usual part of care for every person with diabetes – whatever their age of disease duration.5 Careful daily inspection of the feet is an essential part of preventative care. Practitioners should not rely on people presenting with symptomatic problems, as 50% of people presenting for the first time with insensitive feet have no previous history of neuropathy.5 Additionally, those presenting with peripheral vascular disease may not present with an obvious history of claudication.5 Box 1 shows those individuals at greatest risk of diabetic foot syndrome. Community nurses can teach people to inspect their feet after daily washing. For people whose mobility is compromised, using a mirror to inspect the soles of their feet and in-between their toes is a good way to achieve this. Early referral to a diabetes specialist multi-disciplinary footcare team is good practice, because early and timely referral saves limbs and lives.5,8 A report produced by Diabetes UK, Fast track for a Foot Attack: reducing amputations,8 offers practitioners clear, easy to use advice of who and when to refer to try to expedite care to preserve limbs in diabetes foot syndrome. Guidance exists for practitioners on the identification, prevention of risk and management of diabetic foot syndrome and amputation avoidance in the UK.14 However variation between hospital trusts and geographical variation for the incidence of amputation for diabetic foot syndrome is still evident,18 along with evidence produced annually via the National Diabetes Foot Care Audit which publishes regional variations for hospital trusts.15 Nurses should refer to the foot protection service in their locality following the advice in Box 2.
NICE Guidance NG19
Updated NICE guidance was published in August 2015 entitled NICE NG19 Diabetes Foot Problems: Prevention & Management.6 This guidance highlights the priority in care that people experiencing a diabetes-related foot problem should receive and includes specific steps to ensure that there is a foot protection service for preventing diabetic foot problems, and for treating and managing diabetic foot problems in the community. This foot protection service will have clear protocols and pathways of care to ease referral and expedite access to care for anyone experiencing a diabetes foot problem. Included in this new guidance is rapid access and referral within 24 hours of initial examination of a person’s feet to a named consultant lead of a multidisciplinary foot care service. Box 2 indicates key triggers for referral for practitioners to make people aware of.
The foot protection service will be community-based and the multidisciplinary foot care service will be hospital-based. The guidance recommends that there is robust protocols and clear local pathways for the continued and integrated care of people across all settings, including emergency care and general practice.
Awareness of when to refer someone with a foot problem with diabetes or indeed who may have undiagnosed diabetes is essential. NICE NG19 (2015)6 and Diabetes UK (2014)8,15 promote community awareness to ensure that everyone at risk has equal access to prompt assessment and referral to a community foot protection team.
Conclusion
Amputation is costly in terms of human morbidity and mortality, with reduced quality of life, but also in terms of the fiscal responsibilities within the NHS. We have to be proactive in care to avoid amputation in people with diabetes at risk of, or living with, diabetic foot syndrome. The new NICE NG19 guidance offers clarity for action for every practitioner to expedite care for people at increased risk of avoidable amputation.
References
1. International Diabetes Federation. Diabetes Atlas – 7th edition. idf.org/diabetesatlas (accessed 23 February 2016).
2. Diabetes UK. Number of people with diabetes up to 60% in last decade. diabetes.org.uk/about_us/news/diabetes-up-60-per-cent-in-last-decade-/ (accessed 23 February 2016).
3. Boulton A. The diabetic foot. Diabetic Medicine 2015;43(1):33-7.
4. Boulton A, Vileikyte L, Regnarson-Tennvall et al. The global burden of diabetic foot disease. The Lancet 2005;366:1719-1723.
5. Phillips A & Mehl A. Diabetes mellitus & the increase risk of foot injuries. Journal of Wound Care 2015;24:Supp2:4-7.
6. NICE NG19. Diabetic foot problems: prevention and management. nice.org.uk/guidance/ng19 (accessed 6 February 2016).
7. Health & Social care Information Centre. National Diabetes Audit Report 2, 2012-13. hscic.gov.uk/nad (accessed 5 February 2016).
8. Diabetes UK. Putting feet first: fast track for a foot attack – reducing amputations. diabetes.org.uk/documents/reports/putting-feet-first-foot-attack-report022013.pdf (accessed 6 February 2016).
9. Singh N, Armstrong D, Lipsky B. Preventing foot ulcers in patients with diabetes. JAMA 2005;293(2):217-28.
10. Zubair M, Malik M, Ahmad J. Diabetic foot ulcer: a review. American Journal of Medicine 2015;3(2):28-49.
11. Raspovic K & Wukich D. Self-reported quality of life & diabetic foot infections. The Journal of Foot & Ankle Surgery 2014;53:716-719.
12. Van Acker K. International Diabetes Federation: Diabetic foot disease: When alarm to action is missing. Diabetes Research & Clinical Practice 2015;109:551-552.
13. Wukich D, Hobizal K, Brooks M. Severity of diabetic foot infection & the rate of limb salvage. The Journal of Foot & Ankle Surgery 2013;34:351-358.
14. Diabetes UK. Putting feet first. diabetes.org.uk/Get_involved/Campaigning/Our-campaigns/Putting-feet-first/?gclid=CLnrqsnU5coCFesJwwodrJMKyA (accessed 6 February 2016).
15. Health & Social Care Information Centre. National Diabetes Foot care Audit, 2016. hscic.gov.uk/footcare (accessed 6 February 2016).
