Near-infrared Vision for Microcirculatory Status

Study Overview
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Brief Summary
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The investigators aimed to combine the image of near-infrared vision and machine learning method to evaluate the microcirculatory status of critical ill patients.

Detailed Description
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The heat distribution of body is determined by the circulatory status. The investigators plan to the near-infrared vision to collect heat distribution information of limbs. Then, the machine learning method will be performed to recognize the subtle differences between images. Due to lack of golden standard of microcirculatory status, indirect parameters (such as lactate clearance, capillary refill time) and clinical outcomes will be recorded to evaluate the performance of maching learning model.

Official Title
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Machine Learning-Based Near-infrared Vision to Evaluate the Microcirculatory of Critical Ill Patients: A Prospective Observational Study

Conditions
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Near-infrared Vision, Machine Learning, Microcirculatory Status

Intervention / Treatment
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* Diagnostic Test: Near-infrared Vision Photograph


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age≥18 years; Patients who were transfered to our ICU. Exclusion Criteria: Abnormalities of lower limbs arteries

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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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: Near-infrared Vision Photograph|The near-infrared image will be recorded (by a infrared camera connected to a laptop) for each enrolled patient|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hospital mortality | The rate of patients who died during hospital stay. | From date of admission to our ICU until the date of hospital discharge or date of death from any cause, whichever came first, assessed up to 2 months. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lacteta clearance rate | The percent change of lactate between lactates measured in two time points. This parameter was usually used to guide resuscitation in septic shock. | When the near-infrared image is taken for a patient, the blood gas analysis will be performed immediately to get the value of lactate. After 2-hours, another blood gas analysis will be conducted to get the second value of lactete. | 
| Capillary refill time (CRT) | A noninvasive parameter of peripheral perfusion status. CRT was measured by applying firm pressure to the ventral surface of the right index finger distal phalanx with a glass microscope slide. The pressure was increased until the skin was blank and then maintained for 10 seconds. The time for return of the normal skin color was registered with a chronometer, and a refill time greater than 3 seconds was defined as abnormal.(Hernández 2019.JAMA) | When the near-infrared image is taken for a patient, the capillary refill time will be measured immediately. |