The Effect of Phenylephrine and Ephedrine on Microvascular Blood Flow

Recruiting

Phase N/A Results N/A

Eligibility Criteria

Inclusion Criteria

- Aged 18-60 years
- Male
- Able to consent in English by themselves
- Absence of any exclusion criteria

Exclusion Criteria

- 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
- Participants who have taken part in any other research study in the last three months which involved: taking a drug; being paid a disturbance allowance; having an invasive procedure (eg blood sample >50ml, muscle biopsies) or exposure to ionising radiation.