Systemic diseases affect the whole body and involve one or more body system. Consequently, these types of diseases can have detrimental effects on patient’s health, quality of life and can increase the chance of cardiovascular disease and kidney failure (Venkataraman et al. 2013, Wright 2013). There are numerous systemic pathologies that can cause local neurological and vascular problems within the lower limbs, one of these being diabetes mellitus (DM). It has been documented that poorly controlled diabetes mellitus (i.e hyperglycemia) in conjunction with Peripheral Neuropathy and Peripheral Arterial Disease can lead to an increased risk of foot ulceration, infection and amputation (Aston 2013). which explains in a nutshell why assessing the foot is essential!
Below are some tests and diagnostic tools that can be used as part of the Annual Diabetic Foot Assessment:
Diagnosing peripheral neuropathies
When testing and diagnosing neuropathies within the lower limb the practitioner will note down details from the verbal and visual examination, taking into account the presenting symptoms. The practitioner will then examine the feet for loss of sensation, light and sharp touch, temperature, vibration and proprioception (Boulton 2013). Below are some examples of the tests that can be used during the examination:
Tactile Perception Thresholds (TPT): When testing the feet for TPT’s the practitioner can use a 10mg monofilament. The monofilament is used to test the plantar surface of the foot to gain an insight into the level of pressure the patient has in this area of their foot. The patient will be asked to close their eyes and to voice when they can feel the monofilament touching parts of their feet (Louraki et al. 2012). There is a guideline and risk stratification tool that each allied health professional needs to adhere to when performing this test (SIGN 2010).
Testing for light and sharp touch: This test can be done with cotton wool (Light touch) or by using a pin (Sharp touch). Both tests will determine areas of reduced sense of touch (hypoesthesia) or abnormal sensation (dysaesthesia) (Boulton 2013).
Temperature testing: This part of the practitioner will determine how the patient responds to cold and hot. A cold tuning fork can be used on the foot and then
compared with other parts of the body to gain a perspective on the quality of temperature sensation within the lower limb and feet (Boulton 2013).
Vibration: A tuning fork can be used to test the patient’s reaction to vibration, as this is commonly the first sensation to be lost. This is firstly tested on a bone in the upper body, such as the sternum. If there is diminished or no response to vibration the tuning fork can be applied distally up the body, from the medial malleolus to the anterior superior iliac crest (Nelander et al. 2012).
Proprioception: This will determine how the patient perceives their feet in time and space. This test examines the interphalageal joints of the hallux on both feet. This test is done twice, with the patients eyed open and then closed (Fahmy et al. 2014).
Diagnosing Peripheral Arterial Disease
When testing a patient for peripheral arterial disease there are a number of tests that can be used to diagnose the extent and duration of the disease:
- Physical and verbal examination:
- Ultrasound - Doppler
- Ankle-brachial index
Below are some examples of the tests that may be use:
Vascular testing for pedal pulses: The practitioner will examine the foot to determine if there are pulses in the posterior tibial artery, the anterior tibial artery and the dorsalis pedis artery (Ogrin 2006).
Doppler examination: If the practitioner cannot feel a pulse with touch alone then a hand held Doppler can be used. This device uses ultrasonic waves to detect the blood flow in the vessels. Once the pulse is located it will be classified as triphasic, biphasic or monophasic (Davies et al. 2014).
Ankle- brachial index: This examination compares the blood flow in the ankle with the blood flow in the arm with the patient lying in the supine position. This test can be an indicator of where or if there are occlusions in the arteries of the legs. However, this test can give a faulty reading if the patients vessels are calcified, therefore consideration needs to be taken into account when performing this test (Turns 2011).
Angiography. This is a medical imaging test that will give the examiner a visual picture of what is inside the peripheral arteries. This will determine where and if there are any occlusions that needs to be repaired (Peach and Loftus 2013).
I think thats enough for today, let me know if you have any questions! I am happy to answer any that you have! Paul