DiCART TM Device for Capillary Refill Time Measurement

Study Overview
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Brief Summary
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To estimate peripheral perfusion in shock state, international guidelines recommend the use of capillary refill time, and practitioners currently evaluates it at bedside. However its measurement is not standardized, what should explain the large observer variability reported in different studies. Hence, a device providing a standardized evaluation seems to be helpful. The aim of the study is to evaluate diagnostic performance of such a device recently developped (DiCART TM), in healthy volunteers experiencing vascular occlusion tests to induce impaired perfusion.

Official Title
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DiCART TM Device for Capillary Refill Time Measurement : a Validation Study.

Conditions
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Peripheral Perfusion

Intervention / Treatment
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* Device: measure capillary refill time


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteers Age > 18 years old Informed consent to participate Exclusion Criteria: Vascular disease Diabetes mellitus Dermatosis Cutaneous lesion on a measurement site Anemia Pregnancy Cardiovascular chronic treatment Non affiliation to a social security regime Involvement in other interventional study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: measure capillary refill time<br> | Device: measure capillary refill time<br>* Each time, capillary refill time will be evaluated three times consecutively by clinical method applying a firm pressure with the finger during 15s, then brutally releasing it, and estimating time of skin recoloration with a chronometer and by DiCART TM device Three vascular occlusion tests will be successively performed with a cuff during less than 10 minutes: Arterial vascular occlusion test (50mmHg above systolic arterial pressure of the healthy volunteers), Veinous vascular occlusion test (30mmHg), Control test without vascular occlusion test. Capillary refill time measurements will be repeated just before, during and just after vascular occlusion tests. Randomization determine the order of the vascular occlusion tests. Investigators performing capillary refill time evaluation will be blinded from it. Vascular occlusion tests will be alternatively performed by one and the other limb. The whole protocol will be performed at the upper and then at the lower limb.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Capillary refill time on the thenar eminence evaluated with DiCART TM device. | Diagnostic performance of DiCART TM device to detect a capillary refill time variation on the thenar eminence induced by a vascular occlusion test on the arm. DiCART TM measurement is fully automatized, and may be separated in three consecutive step : An automatized cutaneous compression A video acquisition of cutaneous recoloration Data interpretation The investigators will compute Receptor Operative Characteristics curves with area under the curve, and will determine best threshold and grey zone to evaluate diagnostic performance of DiCART TM device to detect impaired perfusion. | 180 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Capillary refill time evaluated on the knee with DiCART TM device | Diagnostic performance of DiCART TM device to detect a capillary refill time variation on the knee induced by a vascular occlusion test on the leg DiCART TM measurement is fully automatized, and may be separated in three consecutive step : An automatized cutaneous compression A video acquisition of cutaneous recoloration Data interpretation The investigators will compute Receptor Operative Characteristics curves with area under the curve, and will determine best threshold and grey zone to evaluate diagnostic performance of DiCART TM device to detect impaired perfusion. | 180 minutes | 
| Intra -observer variability of capillary refill time measurement with DiCART TM device by performing repetitive measurements by two different investigators. | Two different investigators will realize 5 measurements of capillary refill time with DiCART TM device and standard clinical method in physiological conditions in two different sites (knee and thenar eminence). We will compute least significant change and standard deviation/mean ratio to evaluate observer variability. | 180 minutes | 
| Intra -observer variability of capillary refill time measurement with clinical method by performing repetitive measurements by two different investigators. | Two different investigators will realize 5 measurements of capillary refill time with DiCART TM device and standard clinical method in physiological conditions in two different sites (knee and thenar eminence). We will compute least significant change and standard deviation/mean ratio to evaluate observer variability. | 180 minutes | 
| Inter-observer variability of capillary refill time measurement with DiCART TM device by performing repetitive measurements by two different investigators. | Two different investigators will realize 5 measurements of capillary refill time with DiCART TM device and standard clinical method in physiological conditions in two different sites (knee and thenar eminence). We will compute least significant change and standard deviation/mean ratio to evaluate observer variability. | 180 minutes | 
| Inter-observer variability of capillary refill time measurement with clinical method by performing repetitive measurements by two different investigators. | Two different investigators will realize 5 measurements of capillary refill time with DiCART TM device and standard clinical method in physiological conditions in two different sites (knee and thenar eminence). We will compute least significant change and standard deviation/mean ratio to evaluate observer variability. | 180 minutes | 
| Capillary refill time variation induced by vascular occlusion test on the knee with DiCART TM device | Standard clinical measurement is realized by applying a firm pressure with the finger during 15s and by brutally releasing it. Then, skin recoloration is evaluated visually with a chronometer. | 180 minutes | 
| Capillary refill time variation induced by vascular occlusion test on the knee with standard clinical method | Standard clinical measurement is realized by applying a firm pressure with the finger during 15s and by brutally releasing it. Then, skin recoloration is evaluated visually with a chronometer. | 180 minutes | 
| Capillary refill time variation induced by vascular occlusion test on the thenar eminence with DiCART TM device . | Standard clinical measurement is realized by applying a firm pressure with the finger during 15s and by brutally releasing it. Then, skin recoloration is evaluated visually with a chronometer. | 180 minutes | 
| Capillary refill time variation induced by vascular occlusion test on the thenar eminence with standard clinical method. | Standard clinical measurement is realized by applying a firm pressure with the finger during 15s and by brutally releasing it. Then, skin recoloration is evaluated visually with a chronometer. | 180 minutes | 
| Capillary refill time measured by mathematical algorithms | After the experimental phase, the investigators will develop mathematical algorithms to optimize video data interpretation. | 180 minutes | 
| number of patients with cutaneous lesions | To evaluate the safety of DiCART TM device | 180 minutes | 
| Pain evaluation assessed by numeric rating scale | Pain scale (minimum 1 to maximum 10), 1=No pain,10=Unbearable pain | 180 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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capillary refill time, vascular occlusion test, device, impaired perfusion, healthy volunteers.