Effect of Sodium Nitroprusside on Cerebral Blood Flow

Summary

The brain has a high energy demand and requires continuous blood flow. The blood flow to the brain appears to be unaffected by small changes in blood pressure, but brain blood flow may be reduced by a large reduction in blood pressure. Large reductions in blood pressure are common during anesthesia or bleeding. It is unclear, however, how a given reduction in blood pressure affects blood flow to the brain. In this study, medicine called sodium nitroprusside is used to dilate blood vessels and reduce blood pressure in twenty healthy young men. The study will evaluate whether blood flow to the brain is affected when sodium nitroprusside is used to induce a moderate and a large reduction in blood pressure. Blood flow to the brain is evaluated using ultrasound on the neck. During breathing, oxygen is inhaled and carbon dioxide is exhaled. Carbon dioxide increases brain blood flow whereby changes in respiration can affect the blood flow to the brain. Sodium nitroprusside causes mild hyperventilation, whereby more carbon dioxide is exhaled, which will contribute to a reduction in brain blood flow. Thus, the study will also evaluate how brain blood flow is affected by hyperventilation and by breathing a mix of air and carbon dioxide.

Timeline

Start

2017-11-03

Primary completion

2017-12-04

Completion

2017-12-04

Publications

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Drugs

Indications

No indication recorded.