Cerebral Blood Flow and Metabolism During Hypoxia and Endotoxemia

Study Overview
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Brief Summary
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The objective of the present protocol is to study whether a low level of oxygen in the blood will affect the immune response to as well as cerebral blood flow and metabolism during an infection and, conversely, whether the acute systemic and cerebral physiologic response to hypoxia is modified by an ongoing inflammatory response.

Detailed Description
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The combination of acute infection and a low level of oxygen in the blood is a common phenomenon. Thus, acute hypoxia may complicate severe infections including severe sepsis. Conversely, healthy persons who ascend to moderately high altitudes, which will be associated with a lowering of the inspired oxygen level, may sustain an infection. Even so, it is unknown whether hypoxia modifies the systemic inflammatory response, or, conversely, whether the reaction to hypoxia is influenced by the presence of systemic inflammation. The present protocol aims to measure global cerebral blood flow, metabolism and net flux as well as the systemic response in healthy volunteers who are subjected to either normobaric hypoxia alone (N=12), low-dose IV endotoxin infusion alone (N=12), or a combination of endotoxin infusion and normobaric hypoxia (N=12).

Official Title
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Cerebral Blood Flow and Metabolism During Hypoxia and Endotoxemia

Conditions
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Hypoxia, Endotoxemia, Healthy

Intervention / Treatment
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* Procedure: Endotoxin infusion, Normobaric hypoxia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy nonsmoking male Age 18-45 yrs Exclusion Criteria:

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Male

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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Intervention/Treatment |
| --- |
|Procedure: Endotoxin infusion, Normobaric hypoxia|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cerebral blood flow |  | 0, 9 hours | 
| Cerebral oxygen metabolism |  | 0, 9 hours | 
| Plasma cytokine content |  | 0, 4, 19, 12 hours | 
| Lake Louise Score |  | 0, 4, 9, 12 hours | 
| ESQ-C |  | 0, 4, 9, 12 hours | 
| Endotoxemia Score |  | 0, 4, 9, 12 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cerebral net flux |  | 0, 9 hours | 
| Mean arterial pressure |  | Hourly, 0 through 12 hours | 
| Heart rate |  | Hourly, 0 through 12 hours | 
| Oxygen saturation |  | Hourly, 0 through 12 hours | 
| Body temperature |  | Hourly, 0 through 12 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sepsis, Hypoxia, Altitude Sickness, Endotoxin, Cytokines, Cerebral blood flow, Cerebral metabolism, Reactive oxygen species