Essay: Case study – foot infection / ulceration

The following, is a case study of a male patient, Mr xxxxx Toe, a 48 year old decorator. Mr Toe acquired a foot infection as the result of a penetrating injury caused by a nail that he stepped on while he was working. Furthermore, this provoked an infected ulcer of 0.8 cm in diameter on his right foot which has become slow to heal and according to case notes, is painful when standing.
This case study will outline how Mr Toe acquired this problem, how he can be treated, the precautions a practitioner should undertake to prevent cross infection in clinic and the advice that should be given to the patient about his care.
There are a multitude of factors that can contribute to foot ulcers and infection and each individual patient has a different level of risk due to these factors, which will be highlighted below.
The patient is 45 years old and male. These are two significant factors when identifying patient risk. Research by Merzaa and Tesfayeb (2003) has identified that in the National Hospital discharge survey (1987-90) in the US, the highest percentage of hospital discharges for foot ulcers was present in patients aged 45-64 years. The male sex was also identified as a risk factor in a cross sectional study of 251 patients, whereby 70% of patients with ulcers were male. This highlights the vulnerability of the patient to foot ulcers without consideration of social and cultural factors that the patient may also be affected by.
There is also a link between body weight and foot ulceration which could make the patient at high risk, since at a weight of 16 stone and a height of 5 ft 8, his BMI is calculated as 35. Research by Woong Sohn et al.(2011)  found that the risk of ulceration increased with BMI. A study that followed up diabetic patients for 5 years reported a 20% increased risk in foot ulceration for every 20kg increase in body weight. These results can be explained as pedal stress can be 3 to 5 times body weight, so those with high BMI’s place a lot of pressure of their feet as opposed to those with a lower BMI. When this is applied to the case of Mr Toe, who has caused trauma to his foot, the pressure on the plantar surface of his foot is significant enough to slow down the healing process and cause the ulcer to worsen without treatment.
Case notes of the patient also indicate that there is a family history of type 2 diabetes. Mr Toe’s mother as a first degree relative has a 23% chance of passing on her condition to her son without the influence of environmental factors. A contribution of behaviours such as alcoholism and obesity in addition to genetics increases the risk of type 2 diabetes to 32%. (Cornelis, 2015) In a study that investigated environmental factors such as alcohol consumption on the development of foot ulcers, it was found that those with foot ulcers had a history of more harmful drinking behaviour as 43% of patients from the ulcer group vs. 19% of patients from the control group met the criteria of ‘alcohol abuse ⁄ dependency’ (Altenburg, 2011) These studies suggest that there are genetic and environmental roles in the development of ulcers and that the patient’s risk is increased because of these factors.
Mr Toe works as a full time decorator, therefore he is on his feet for the majority of the day. He wears work boots that are not supportive and are not adequate for every day wear. Firstly, the boots are slip on. This means that the foot is not in a normal stance for walking. The phalanges tend to claw with this type of shoe to increase grip on the shoe. This could increase strains, especially on the metatarsophalangeal joint, where the ulcer is, limiting healing.
Furthermore, the footwear have a PVC upper surface which is a non- breathable material.  This can hold moisture in the shoe and cause the patients feet to sweat. This creates a perfect environment for bacteria to multiply and may have played a part in an infection. The soles of the shoes are worn and thin, this means there are less shock absorbing properties, meaning the forefoot is more likely to be strained or damaged by pressure from walking. This is particularly significant in this case study, as this patient has observed early heel lift, which would increase the pressure on the forefoot even further.
It has been identified in the Orthopaedic Assessment that the patient suffers from Tibial varum, an abnormality in the tibia that causes the legs to bow outwards. This can cause more loading and weight bearing on the lateral side of the foot creating an excessively pronated foot. The misalignment of the tibia can give rise to abnormal function of the ankle and subtalar joints, which begin to rotate in the frontal plane compensating for the abnormality. This mechanism causes more problems, one of these relevant to the case study is the effect on the 1st metatarsophalangeal joint, where the patient’s ulcer is, as it creates a limitation of mobility in the joint. (Ribbans , 2009)
Sumpio is able to summarise the biomechanical causes of ulcers. Altered foot biomechanics, limited joint mobility, and bony deformities have been associated with an increased risk of ulceration. Abnormalities in foot biomechanics result in a dysfunctional gait and can lead to more damaging structural changes in the foot. Bony deformities, such as deformities of the metatarsal heads, increase pressure on them. A decrease in the surface area of the tissue below a metatarsal head with rigid deformities leads to increased forces or pressure.(Sumpio,2000)
Overall, there is a range of potential risk factors that the patient has been subjected to which has contributed to the development of the ulcer. In the following paragraph, the suitable treatment options for the patient will be outlined.
Firstly, treatment often includes debridement (trimming away or removal) of all necrotic, callused, and fibrous tissue. Following debridement, the ulcer needs to be cleaned as it is infected. This can be done with saline and suitable antibiotics should be prescribed. A general antibiotic may be more suitable for the patient, as taking a swab and waiting for the results is time consuming and the infection needs to be removed for the ulcer to heal. Topical antibiotics such as bacitracin, Neomycin, or Polymyxin B may be effective in an infected wound, like the patient’s. Further infection of a foot ulcer can be prevented with: Salt foot baths ,disinfecting the surrounding area of skin with salt solution or alcohol, frequent dressing changes to keep the ulcer dry, enzyme treatments, dressings containing calcium alginates (to inhibit bacterial growth)  (Congdon, 2015). Suitable dressings with these properties may include Kaltostat and Sorbsan. Dressings should also prevent tissue dessication, absorb excess fluid, while protecting the wound from contamination. Other types of dressings that do this include hydrogels, foams, absorbent polymers, growth factors, and skin replacements. Becaplermin is a dressing that contains growth factor and has been shown in double-blind placebo controlled trials to significantly increase wound healing. This can be considered for ulcers that fail to heal with standard dressings. (Kruse and Edelman. 2006) This could be a useful dressing in the treatment of Mr Toe, if his ulcer fails to heal.
Offloading is an important part of ulcer treatment, since this reduces pressure on the wound, allowing it to heal more effectively. Research conducted by Kruse and Edelman suggests offloading with a wheelchair or crutches to halt weight bearing is most effective. Total contact casts (TCCs) are difficult and time consuming to apply but significantly reduce pressure on wounds and have been shown to heal between 73 -100% of all wounds treated with them. Clinicians often prefer to give patients removable cast walkers because they do not have some of the disadvantages of TCCs. Being able to remove the cast means that the patient can easily inspect the wound, have frequent dressing changes and be able to detect a possible infection. But removability has a large disadvantage in that studies have shown that patients wear them only 30% of the time when they walk. For the case study of Mr Toe, offloading may not be relevant at this stage of ulcer treatment since it is an acute ulcer. However, if the ulcer continues to worsen, then offloading by one of these methods may be effective to allow the wound to heal.  Mr Toe has an acute ulcer, which could be offloaded most simply, by providing a foam covering in the form of a ring shape fitting inside his shoe, which would accommodate the ulcer, relieving pressure and allowing it to heal.
There are precautions that need to be taken in order to prevent cross contamination in clinic. Standard Infection Control Precautions (SICP) are designed to prevent cross transmission from recognised and unrecognised sources of infection.  Handwashing is a basic requirement and should be done for 15 seconds to 3 minutes, five times during patient contact. Hands should be clean before patient contact, before performing a treatment, after body fluid exposure risk, after patient contact and after being in a patient’s surroundings. This is to avoid transferring contaminants between patients, when a practitioner comes into contact with them. By having good handwashing practices, the risk of cross contamination is much more limited. The use of Personal Protective Equipment (PPE) is also essential for health and safety. This includes the use of aprons, gloves and masks. Items such as gloves and aprons should be changed before and after contact with patients and performing procedures. (NHS Professionals, 2010) Furthermore, an autoclave should always be used to sterilise equipment after procedures such as debridement. Precautions should be taken with infected ulcers. For example, if the patient places the foot with an infected ulcer on surfaces, then these surfaces need to be sanitised in order to prevent infection being transmitted to other patients. This is especially important when seeing patients who are highly vulnerable to contracting infections, such as those with diabetes.
After the ulcer has been adequately treated, advice should be given to the patient about how to care for their wound when they are at home. Suitable advice for Mr Toe should include daily inspection of the ulcer which should occur before reapplying a dressing. The dressing should be reapplied twice daily when the foot is clean and dry. The patient can clean their foot in a salt bath as this sanitises the wound. The foot should also be kept elevated for as much time as possible, increasing the blood flow to the feet and therefore the rate of healing. Furthermore, walking without an adequate dressing on the ulcer should be avoided, to prevent further infection. Finally, if there is more redness and warmth this is a sign of infection which will prevent the ulcer from healing and the patient should contact a practitioner. (Edwards, 2008)
Other advice would include taking the prescribed antibiotics until the course has finished. A recommendation for new footwear should be advised. The patient’s shoes are not adequate as they have a thin sole and there is splitting in the upper surface. The material of the patient’s current footwear is PVC, a non- breathable material which encourages moisture and therefore bacteria, increasing the risk of infection. Shoes made of leather minimise this risk since they are more breathable, so are more suitable for every day footwear.  New shoes that are wide enough for the patient’s feet are also required, as excess pressure is not beneficial in the treatment of ulcers.  As well as this, a thick sole would be beneficial if the patient commonly comes into contact with discarded sharp objects.