The Effect of Phenylephrine and Ephedrine on Microvascular Blood Flow

NCT02252627 | Unknown

• 1 other identifier: H10102013
• Study Type: observational
• Target: 8
• Locations: 1 country
• Sites: 1

Brief 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

Outcome Measures

Primary Outcomes (1)

• Change in microvascular blood flow

  Microvascular visceral blood flow is assessed using contrast enhanced ultrasound, and will be assessed before and after the administration of each drug.

  30 minutes

Secondary Outcomes (1)

• Change in stroke volume

  30 mins

Study Arms (1)

Group 1

Healthy volunteers

Drug: Administration of phenylephrine; Other: Measurement of stroke volume; Other: Contrast enhanced ultrasound scan; Drug: Administration of ephedrine

Interventions

Administration of phenylephrine DRUG

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.

Group 1

Measurement of stroke volume OTHER

The measurement of stroke volume will be performed using an Oesophageal Doppler Monitor

Group 1

Contrast enhanced ultrasound scan OTHER

Microvascular blood flow will be measured using a contrast enhanced ultrasound scan

Group 1

Administration of ephedrine DRUG

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.

Group 1

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Healthy male volunteers

You may qualify if:

• Aged 18-60 years
• Male
• Able to consent in English by themselves

You may not qualify if:

• A BMI \< 20 or \> 28 kg•m2
• Active cardiovascular disease: uncontrolled hypertension (BP \> 140/90), angina, heart failure (class III/IV), arthymia, right to left cardiac shunt or recent cardiac event
• Individuals taking alpha or beta-adrenergic blocking agents, monoamine oxidase inhibitors, tricyclic antidepressants, serotonin or noradrenaline selective reuptake inhibitors, quinidine, cardiac glycosides or buspirone (or who have ceased taking them in the previous 14 days¬)
• Cerebrovascular disease: previous stroke, aneurysm (large vessel or intracranial)
• Peripheral vascular disease
• Metabolic disease: hyper and hypo parathyroidism, untreated hyper and hypothyroidism, Cushing's disease, types 1 or 2 diabetes
• Active inflammatory bowel disease, or renal disease
• Known prostatic hypertrophy
• Malignancy
• Clotting dysfunction
• Previous oesophageal surgery
• Individuals with a known history of oesophageal varices
• Individuals with a known history of epistaxis
• Family history of early (\<55y) death from cardiovascular disease
• Known sensitivity to SonoVue, ephedrine or phenylephrine

Sponsors & Collaborators

• University of Nottingham: lead

Study Sites (1)

University of Nottingham, School of Medicine, Division of Medical Sciences and Graduate Entry Medicine

Derby, Derbyshire, DE22 3DT, United Kingdom

RECRUITING

Study Officials

• John P Williams, PhD

  University of Nottingham

  PRINCIPAL INVESTIGATOR

Central Study Contacts

John P Williams, PhD

CONTACT

john.williams7@nhs.net

Study Design

• Study Type: observational
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 25, 2014
• First Posted: September 30, 2014
• Study Start: August 1, 2014
• Primary Completion: August 1, 2015
• Study Completion: August 1, 2015
• Last Updated: January 27, 2015

Record last verified: 2015-01

Locations

GB (1)