Optical Assessment on Brain Death Via a Oxygen Supply Procedure

Study Overview
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Brief Summary
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This study aims to evaluate brain death with optical probes. The changes of hemodynamic parameters including oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) were detected by near infrared spectroscopy probes attached on the forehead of patients. A multiple-phase protocol at varied fraction of inspired O2 were utilized during the assessment.

Detailed Description
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Brain death is an irreversible loss of all brain functions, and the assessment is crucial for organ supply for transplantation. The noninvasive, sensitive, universally available and timely ancillary method to assess brain death has not been established. This study aims to evaluate brain death with optical probes. The changes of hemodynamic parameters including oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) were detected by near infrared spectroscopy probes attached on the forehead of patients. A multiple-phase protocol at varied fraction of inspired O2 were utilized during the assessment. The concentration changes ratios of oxyhemoglobin to deoxyhemoglobin (Δ[HbO2]/Δ[Hb]) in the cerebral cortex of brain-dead patients were significantly higher than those of healthy subjects.

Official Title
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Optical Assessment on Brain Death Via a Multiple-phase Protocol at Varied Fraction of Inspired O2

Conditions
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Brain Death

Intervention / Treatment
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* Procedure: Oxygen supply of high-low-high procedure
* Procedure: Oxygen supply of low-high-low procedure
* Device: Optical monitor for hemodynamic parameter.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who have had brain death or serious brain trauma. Healthy people who are interested in optical assessment of hemodynamic parameters Exclusion Criteria: Patients who are in pregnancy or have plan to conception. Patients who have vertebra surgery or have plan of surgery. Patients who are inappropriate to join this trial judged by the radiologists or specialists. AIDS, Active Hepatitis, Tuberculosis, Syphilis Patients who regularly take anticoagulants, antiplatelet drugs

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Brain death patients for HLH Oxygen<br>Brain-dead patients were supplied with oxygen at varied FIO2 at medical premised range.The protocol is Oxygen supply of high-low-high procedure. During the procedures, the Δ[Hb] and Δ[HbO2] time courses were collected by Optical monitor for hemodynamic parameter. | Procedure: Oxygen supply of high-low-high procedure<br>* The protocol consisted of 1-hour resting, 3-minute baseline measurement, half-hour measurement at 60% FIO2 (phase I, high oxygen), half-hour measurement at 40% FIO2 (phase II, low oxygen) and half-hour measurement at 60% FIO2 (phase III, high oxygen).<br>Device: Optical monitor for hemodynamic parameter.<br>* Near infrared spectroscopy probes of tow wavelengths were attached on the subjects' foreheat to detect the changes of hemodynamic parameters.<br>|
| Brain death patients for LHL Oxygen<br>Brain-dead patients were supplied with oxygen at varied FIO2 at medical premised range.The protocol is Oxygen supply of low-high-low procedure. During the procedures, the Δ[Hb] and Δ[HbO2] time courses were collected by Optical monitor for hemodynamic parameter. | Procedure: Oxygen supply of low-high-low procedure<br>* The protocol consisted of 1-hour resting, 3-minute baseline measurement, half-hour measurement at 40% FIO2 (phase I, low oxygen), half-hour measurement at 60% FIO2 (phase II, high oxygen) and half-hour measurement at 40% FIO2 (phase III, low oxygen).<br>Device: Optical monitor for hemodynamic parameter.<br>* Near infrared spectroscopy probes of tow wavelengths were attached on the subjects' foreheat to detect the changes of hemodynamic parameters.<br>|
| Healthy people for HLH Oxygen<br>Healthy people were supplied with oxygen at varied FIO2 at medical premised range.The protocol is Oxygen supply of high-low-high procedure. During the procedures, the Δ[Hb] and Δ[HbO2] time courses were collected by Optical monitor for hemodynamic parameter. | Procedure: Oxygen supply of high-low-high procedure<br>* The protocol consisted of 1-hour resting, 3-minute baseline measurement, half-hour measurement at 60% FIO2 (phase I, high oxygen), half-hour measurement at 40% FIO2 (phase II, low oxygen) and half-hour measurement at 60% FIO2 (phase III, high oxygen).<br>Device: Optical monitor for hemodynamic parameter.<br>* Near infrared spectroscopy probes of tow wavelengths were attached on the subjects' foreheat to detect the changes of hemodynamic parameters.<br>|
| Healthy people for LHL Oxygen<br>Healthy people were supplied with oxygen at varied FIO2 at medical premised range.The protocol is Oxygen supply of low-high-low procedure. During the procedures, the Δ[Hb] and Δ[HbO2] time courses were collected by Optical monitor for hemodynamic parameter. | Procedure: Oxygen supply of low-high-low procedure<br>* The protocol consisted of 1-hour resting, 3-minute baseline measurement, half-hour measurement at 40% FIO2 (phase I, low oxygen), half-hour measurement at 60% FIO2 (phase II, high oxygen) and half-hour measurement at 40% FIO2 (phase III, low oxygen).<br>Device: Optical monitor for hemodynamic parameter.<br>* Near infrared spectroscopy probes of tow wavelengths were attached on the subjects' foreheat to detect the changes of hemodynamic parameters.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Δ[HbO2] | The changes of oxyhemoglobin concentrations in prefrontal cortex. | 1 day during the whole experiment | 
| Δ[Hb] | The changes of deoxyhemoglobin concentrations in prefrontal cortex. | 1 day during the whole experiment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate | Heart rate of patient recorded by bed-side physiological monitor. | 1 day during the whole experiment | 
| Blood pressure | Blood pressure of patient recorded by bed-side physiological monitor. | 1 day during the whole experiment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Brain death, Oxygen metabolism, Near infrared spectroscopy