Arterial assessment
Assessing the arterial supply to the foot on which an ulcer is located is very important for three main reasons:
- Potential to heal
- Ability to control infection using systemic antibiotics
- Influence on type of infecting micro-organisms
Current best practice requires all individual’s with diabetic foot ulcers to have an Ankle Brachial Pressure Index (ABPI) measurement of their lower limbs. The ABPI is a ratio dividing the highest pressure recorded from dorsalis pedis and posterior tibial arteries with the systolic pressure of the highest brachial arterial pressure. Interpretation of the ABPI result is given below:
- 0.9-1-3 is normal with most people having a ratio between 1 and 1.2.
- > 1.3 is associated with calcification of the arteries.
- 0.5-0.9 indicates some arterial disease and may be associated with the start of arterial lower limb complications such as claudication. Refer to a vascular surgeon if symptoms become problematic or the ulcer fails to heal.
- <0.5 indicates severe arterial disease and urgent referral to a vascular surgeon should be sought.
In patients’ with arterial disease, anaerobic infections are more likely and so the choice of antibiotic will need to cover this spectrum of infection. It is also important to bear in mind that, in arterial compromise, antibiotic penetration to the ulcer is diminished and in more severe cases use of intravenous antibiotics should be considered. Close liaison with the vascular team in compromised patients is paramount to see if arterial reconstruction is a possibility.
Further education on assessment and management of lower limb arterial disease can be found at http://elearning.nice.org.uk/
