Online Noninvasive Assessment of Human Brain Death and Deep Coma by Near-infrared Spectroscopy

Study Overview
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Brief Summary
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This study aims to assess brain death and deep coma with the self-made near infrared spectroscopy (NIRS) instrument. The investigators used the noninvasive method to monitor the Δ[HbO2] (the concentration changes in oxy-hemoglobin) and Δ[Hb] (the concentration changes in deoxy-hemoglobin) in the region around the forehead of medically evaluated participating patients and healthy subjects. 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, while deep coma is a profound state of unconsciousness associated with depressed cerebral activity. Timely distinguishing the two states is crucial for saving patients. The noninvasive, sensitive, universally available, and timely ancillary method to assess brain death and deep coma has not been established. This study aims to explore a noninvasive and straightforward way in brain death and deep coma online assessment. The changes of hemodynamic parameters including oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) were detected by near infrared spectroscopy instrument attached on the forehead of participators. A multiple-phase protocol at varied fraction of inspired O2(FIO2) were utilized during the assessment. Then the investigators compared the multiple physiological parameters changes among different groups at different FIO2.

Official Title
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Online Noninvasive Assessment of Human Brain Death and Deep Coma by Near-infrared Spectroscopy With Protocol at Varied Fraction of Inspired O2

Conditions
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Brain Death, Coma

Intervention / Treatment
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* Procedure: Oxygen supply of high-low-high procedure
* Procedure: Oxygen supply of low-high-low procedure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who have had brain death or serious brain trauma. Patients who have deep coma with autonomous respiration according to GCS coma Scale 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 the NIRS instrument 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). Device: Optical monitor for hemodynamic parameter. Near infrared spectroscopy instrument was attached on the subjects' forehead 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 the NIRS instrument 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). Device: Optical monitor for hemodynamic parameter. Near infrared spectroscopy instrument was attached on the subjects' forehead to detect the changes of hemodynamic parameters.<br>|
| Deep coma patients for HLH Oxygen<br>Deep coma 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 the NIRS instrument 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). Device: Optical monitor for hemodynamic parameter. Near infrared spectroscopy instrument was attached on the subjects' forehead to detect the changes of hemodynamic parameters.<br>|
| Deep coma patients for LHL Oxygen<br>Deep coma 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 the NIRS instrument 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). Device: Optical monitor for hemodynamic parameter. Near infrared spectroscopy instrument was attached on the subjects' forehead 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). Device: Optical monitor for hemodynamic parameter. Near infrared spectroscopy instrument was attached on the subjects' forehead 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). Device: Optical monitor for hemodynamic parameter. Near infrared spectroscopy instrument was attached on the subjects' forehead 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, Deep coma, Oxygen metabolism, Near infrared spectroscopy