Some of the facts around Type 2 Diabetes Mellitus (T2DM)
Type 2 Diabetes Mellitus (T2DM) is a rising public health burden and over 10% of the National Health Service (NHS) entire budget is used up in managing the complications of this disease. Males are 23% more likely to have T2DM and those who suffer social deprivation are 75% more likely to develop the disease than those least deprived (Sharma et al, 2015). Globally the figure for diabetes is estimated to increase from 415 million in 2015 to 642 million by 2040 which is and will pose enormous socio-economic and health challenges. Development of T2DM is linked to genetic factors, obesity, sedentary lifestyle, and aging alongside consumption of energy-dense food and physical inactivity (Lucoveis, 2021. Dendup, 2018).
T2DM is caused by either the poor production of insulin (insulin deficiency) or body cells which are unable to use the insulin produced properly (insulin resistance) resulting in excessive blood sugars which cause severe damage to many of the body systems, such as the eyes, kidneys, neurological, heart and peripheral circulation. In 2015 about 26 million people developed foot ulcers annually (IWGDF, 2019) and among all amputations associated with diabetic foot ulcers, 83% were major and 96% minor and both carried a high mortality rate of up to 70% of patients dying within 5 years (IDF, 2017a). Therefore, the close observation and prevention of foot ulcers, in this cohort of patients, is extremely important and starts with identifying who is at risk by examination of feet annually, looking for signs of reduced neurological sensations (peripheral neuropathy) and reduced tissue perfusion (Peripheral arterial disease) (Van, Netten, 2015. Dendup, 2018).
So, what puts diabetic patients at higher risk of developing pressure ulcers?
Although the answer to this question is multifactorial and complex, there are 3 key risk factors which can put diabetic patients at higher risk of developing pressure ulcers. Discussing these, as Health Care Professionals (HCP), will help to improve knowledge and promote extra vigilance in preventing pressure ulcer development.
Peripheral Arterial Disease (PAD): There is an increased risk (11% of diabetic patients compared with 4% of non-diabetic patients) of T2DM patients developing PAD which itself accounts for up to 50% of diabetic foot ulcers (Altoijry, et al. 2021). The reduction in blood supply/ flow associated with narrowing of the peripheral arteries contributes to the development of ulcers of the leg and a study by Twilley & Jones (2016) suggest a strong relationship between PAD and the development of pressure ulcers to the heal which are more likely to present as deeper and more severe pressure ulcers (Categories 2, 3 and 4) than patients without PAD. It is important to establish the presence and extent of PAD, through reading the patient’s clinical history, liaising with the Diabetic specialist nurse, reviewing vascular input or through arranging a specialist Ankle Brachial Pressure Index (ABPI) test. This is so that preventative nursing or support surface interventions can be reviewed as it is possible that normal preventative methods and standard support surfaces may be less effective while the underlying pathology persists. It will also allow targeted interventions, to prevent pressure ulcers, such as heel elevation to be established from the start of their care journey.
Loss of foot protection sensitivity: Hicks & Selvin (2019) states that the prevalence of DPN, in adults with diabetes, is between 6% and 51% and that eventually nearly 50% of diabetic adults will be affected. It is thought to be caused by nerve dysfunction and cell death due to oxidative stress and inflammation (Hicks and Selvin, 2019). The clinical manifestations are variable but due to the lack of sensation in the foot there is an inability to sense light pressure leading to a daily loading of high pressures, through the foot. This can lead to trauma and injury which the patient cannot feel and results in changes to the biomechanics of the foot leading to bone deformity, development of callus, hammer toes, gait changes, poor foot hygiene. This lack of sensation often prevents people with DPN from responding promptly to abnormal mechanical stresses and seek advice from Health Care Professionals (HCPs) (van Netten et al, 2015. Duan et al, 2022. Hicks and Selvin, 2019). This can lead to patients wearing ill-fitting footwear, not noticing rubbing or pressure over bony prominences, developing trauma from debris in the footwear that is not felt, chronic pain which causes reduced mobility, delays in recognising signs of infection, or failure to relieve pressure over the heel area due to lack of sensation.
Elevated levels of mechanical stress on the foot: Plantar pressure forms the vertical component of the load experienced, through the feet, during normal walking gait. Peripheral neuropathy and lack of sensation results in elevated pressures in the plantar region of the foot resulting in tissue inflammation, tissue stress and breakdown increasing the risk of ulcer formation. It is also suggested the repetitive, multidirectional shear stress caused on the surface and deeper layers of the skin, contributes to ulcer formation (Jones et al, 2021). In a study by de Wert et al. (2019) they showed that the reactive hyperaemic skin response (where the tissue, under pressure, flushes red when this pressure is removed) was decreased in patients with T2DM and therefore tissue was not responding as it should to abnormal mechanical loading.
What are our Professional Responsibilities? The Guidelines on prevention of foot ulcers in persons with diabetes (IWGDF 2019) describe five key elements that underpin efforts to prevent foot ulcers:
1. Identifying the at-risk foot. Looking at history, vascular status, palpation or sounding out of pedal pulses, use of monofilaments to check sensation (or if monofilament is not available lightly touch the tips of the toes of the patient with the tip of your index finger for 1 to 2 seconds).
2. Regularly inspecting and examining the at-risk foot. Assessing skin colour, temperature, presence of callus or oedema. Checking for bone deformities (should be checked when patients are both lying down and standing up). Check footwear that it is adequate and fitting well. Check foot hygiene for health of toenails, fungal infections, skin integrity and ensure patient wears clean socks.
3. Educating the patient, family, and health care professionals. It is agreed that education plays an important role in prevention of ulceration. Improving the patient’s footcare knowledge, how to recognise pre-ulcer signs and what steps they need to take as soon as they see changes. This should be structured and considers the following:
- Can the person preform a foot inspection and if not, who could do it for them on a regular basis?
- Do they know who to contact if they get a blister, cut or scratch?
- Wash feet daily and inspect them carefully and dry well, especially between the toes.
- Do not use heaters or hot water bottles against the skin of the feet.
- Use emollients to moisturise the skin but not between the toes.
- Cut toenails straight across.
4. Ensuring routine wearing of appropriate footwear.
- Should be reviewed by a Diabetic Podiatrist so their walking gait, structure of the foot and footwear can be assessed as appropriate.
- Avoid tight footwear or any footwear with rough edges or uneven seams.
- Be aware that if they have lower limb oedema their feet may swell during the day and cause footwear to become tighter fitting.
- Avoid walking barefoot or in socks, without footwear. Thick soles to slippers are preferred.
5. Treating risk factors for ulceration.
- Should be reviewed by a Diabetic Podiatrist for the removal of callus, draining and protecting blisters, appropriate treatment of ingrown or fungal toenail beds.
- Any intervention to the diabetic foot should be performed by an appropriately trained health care professional.
- Any pre-ulcer signs, ulceration, signs of infection or deterioration of status of ulcer should be escalated as a matter of priority to the appropriate service such as Podiatry or Tissue Viability.
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