Critical Limb Ischemia, Critical Lower Limb Ischemia, Diabetic Foot, Diabetic Foot Ulcer, Peripheral Arterial Disease, Peripheral Artery Disease, Peripheral Vascular Diseases
Conditions
Keywords
Peripheral Vascular Diseases, Diabetic Foot, Critical Limb Ischemia, Diagnosis, Peripheral arterial disease, Diabetic foot ulcer, Duplex ultrasound, Ultrasound
Brief summary
This study will focus on determining; * How accurate the test is in detecting poor circulation * How it's accuracy compares to other commonly used tests, and * Whether test results are linked to the chance of ulcer healing or amputation. Across 2 hospitals, 305 diabetic patients will be scanned using the focused ultrasound test as well as other commonly used tests to detect poor circulation. Their results will be compared to a full version of the ultrasound test to identify the most accurate.
Detailed description
In the UK, over 7,000 amputations are performed each year because of diabetes. Most of these (80%) occur when a foot wound, also known as an ulcer, does not heal. The most important cause of this is poor circulation to the feet. Currently, there are no accurate tests that foot specialists can use to detect poor circulation when they see patients. Because of this, poor circulation can be missed and its treatment delayed. A focused ultrasound test at the ankle, using a sensor and gel on the skin, can detect poor circulation. It is safe, painless and I have previously proven that it can be learned and performed quickly. It may help avoid amputations by detecting poor circulation so that it can be treated quickly.
Interventions
DIAGNOSTIC_TESTTranscutaneous pressure of oxygen (TcPO2)
Measurements will be taken from the dorsum of the foot using an automated machine equipped with Clark electrodes.
DIAGNOSTIC_TESTToe Brachial Pressure Index (TBPI)
TBPI will be measured using the photoplethysmography (PPG) method, employing an infrared sensor placed on the hallux and index finger.
DIAGNOSTIC_TESTPodiatry Ankle Duplex scan (PAD-scan)
Podiatry ankle duplex scan (PAD-scan) involves using an ultrasound machine to visualise the anterior and posterior tibial arteries at the ankle.
DIAGNOSTIC_TESTDuplex Assist
Continuous Doppler device which gives visual display of arterial spectral waveform at the ankle.
DIAGNOSTIC_TESTAnkle Brachial Pressure Index (ABPI)
A sphygmomanometer-cuff placed at the ankle and a handheld continuous wave Doppler device will be used to measure the systolic pressure of the DPA and PTA.
Sponsors
Imperial College Healthcare NHS Trust
Study design
Observational model
OTHER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* All diabetic patients presenting to the diabetic foot clinics will be eligible for the study.
Exclusion criteria
* Patients unable to provide informed consent will also be excluded.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diagnostic Accuracy | 1 hour; all tests will be performed on the same day of presentation. | Diagnostic accuracy of the PAD-scan and other bedside tests will be compared to the results of a full lower limb Duplex Ultrasound scan (reference test). |
Countries
United Kingdom
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Study Participants Participants with diabetes were consecutively enrolled into the study across 2 centers. | 305 |
| Total | 305 |
Baseline characteristics
| Characteristic | Study Participants | — |
|---|---|---|
| Active ulceration | 123 Participants | — |
| Age, Continuous | 72 years | — |
| Neuropathy | 203 Participants | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Sex: Female, Male Female | 99 Participants | — |
| Sex: Female, Male Male | 206 Participants | — |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 305 |
| other Total, other adverse events | 0 / 305 |
| serious Total, serious adverse events | 0 / 305 |
Outcome results
Primary
Diagnostic Accuracy
Diagnostic accuracy of the PAD-scan and other bedside tests will be compared to the results of a full lower limb Duplex Ultrasound scan (reference test).
Time frame: 1 hour; all tests will be performed on the same day of presentation.
Population: Missing data were observed in 7 (2.3%) patients for ABPI, 71 (23.3%) patients for TBPI and 16 (5.2%) patients for TcPO2.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Study Participants | Diagnostic Accuracy | PAD-scan sensitivity | 95 Percent |
| Study Participants | Diagnostic Accuracy | PAD-scan specificity | 77 Percent |
| Study Participants | Diagnostic Accuracy | TBPI specificity | 86 Percent |
| Study Participants | Diagnostic Accuracy | Pulse sensitivity | 43 Percent |
| Study Participants | Diagnostic Accuracy | Pulse specificity | 81 Percent |
| Study Participants | Diagnostic Accuracy | Doppler (audible) sensitivity | 74 Percent |
| Study Participants | Diagnostic Accuracy | Doppler (audible) specificity | 76 Percent |
| Study Participants | Diagnostic Accuracy | Doppler (visual) sensitivity | 83 Percent |
| Study Participants | Diagnostic Accuracy | Doppler (visual) specificity | 75 Percent |
| Study Participants | Diagnostic Accuracy | ABPI sensitivity | 60 Percent |
| Study Participants | Diagnostic Accuracy | ABPI specificity | 75 Percent |
| Study Participants | Diagnostic Accuracy | TcPO2 sensitivity | 31 Percent |
| Study Participants | Diagnostic Accuracy | TcPO2 specificity | 79 Percent |
| Study Participants | Diagnostic Accuracy | TBPI sensitivity | 60 Percent |