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The Effect of Phenylephrine and Ephedrine on Microvascular Blood Flow

NCT02252627 · Status: UNKNOWN · Type: OBSERVATIONAL · Enrollment: 8

Last updated 2015-01-27

No results posted yet for this study

Summary

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.

Conditions

  • Healthy Volunteers

Interventions

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.

Sponsors & Collaborators

  • University of Nottingham

    lead OTHER

Principal Investigators

  • John P Williams, PhD · University of Nottingham

Eligibility

Min Age
18 Years
Max Age
60 Years
Sex
MALE
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2014-08-31
Primary Completion
2015-08-31
Completion
2015-08-31

Countries

  • United Kingdom

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02252627 on ClinicalTrials.gov