The Effect of Phenylephrine and Ephedrine on Microvascular Blood Flow
|ClinicalTrials.gov Identifier: NCT02252627|
Recruitment Status : Unknown
Verified January 2015 by University of Nottingham.
Recruitment status was: Recruiting
First Posted : September 30, 2014
Last Update Posted : January 27, 2015
During operations to treat abdominal problems the blood pressure can fall, resulting in falls in blood flow to the vital organs. This fall can be treated by the administration of drugs that cause constriction of blood vessels. Although these drugs correct falls in blood pressure, it is unclear what effect they have on blood flow from the heart and to the vital organs.
In this study of healthy volunteers we aim to better understand the changes in blood flow in both small and large vessels that occur in response to administration of these drugs. To do this we will use two different techniques of ultrasound imaging. A narrow (4-5mm) ultrasound probe will be inserted into the oesophagus via a nostril to measure blood flow in a major blood vessel. A second probe will rest on the abdomen and will record changes in blood flow in small vessels of the liver. Two drugs which raise the blood pressure via different mechanisms will be administered and the changes in flow from the heart and to vital organs will be measured and compared.
|Condition or disease||Intervention/treatment|
|Healthy Volunteers||Drug: Administration of phenylephrine Other: Measurement of stroke volume Other: Contrast enhanced ultrasound scan Drug: Administration of ephedrine|
|Study Type :||Observational|
|Estimated Enrollment :||8 participants|
|Official Title:||An Observational Study to Test the Effect of the Vasoactive Drugs Phenylephrine and Ephedrine on the Stroke Volume and Microvascular Blood Flow of Healthy Volunteers|
|Study Start Date :||August 2014|
|Estimated Primary Completion Date :||August 2015|
|Estimated Study Completion Date :||August 2015|
Drug: Administration of phenylephrine
Intravenous phenylephrine will be administered in 50-100 microgram increments until the mean arterial blood pressure has increased by 25% compared to baseline, or until a maximum dose of 1mg has been administered.
Other: Measurement of stroke volume
The measurement of stroke volume will be performed using an Oesophageal Doppler Monitor
Other: Contrast enhanced ultrasound scan
Microvascular blood flow will be measured using a contrast enhanced ultrasound scan
Drug: Administration of ephedrine
Intravenous ephedrine will be administered in 3-6mg increments until the mean arterial blood pressure has increased by 25% compared to baseline, or until a maximum dose of 30mg has been administered.
- Change in microvascular blood flow [ Time Frame: 30 minutes ]Microvascular visceral blood flow is assessed using contrast enhanced ultrasound, and will be assessed before and after the administration of each drug.
- Change in stroke volume [ Time Frame: 30 mins ]The change in stroke volume will be assessed using an Oesophageal Doppler Monitor, and will be assessed before and after the administration of each drug.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02252627
|Contact: John P Williams, PhDemail@example.com|
|University of Nottingham, School of Medicine, Division of Medical Sciences and Graduate Entry Medicine||Recruiting|
|Derby, Derbyshire, United Kingdom, DE22 3DT|
|Contact: David Read, BMBS firstname.lastname@example.org|
|Principal Investigator: John P Williams, PhD|
|Sub-Investigator: Thomas P Heinink, BMBS|
|Sub-Investigator: Jonathan N Lund, MD|
|Sub-Investigator: Bethan E Phillips, PhD|
|Sub-Investigator: David Read, BMBS|
|Principal Investigator:||John P Williams, PhD||University of Nottingham|