Autonomic Cardiovascular Control in Response to Blood Volume Reduction in Blood Donors

Autonomic Cardiovascular Control in Response to Blood Volume Reduction in Blood Donors

The function of the autonomic nervous system can be assessed using baroreflex sensitivity (BRS) and heart rate variability (HRV). Decreased HRV has been shown to be predictive of morbidity and mortality in diverse medical conditions such as acute myocardial infarction, aneurysmal subarachnoid haemorrhage, autoimmune diseases, sepsis and surgery.

The function of the autonomic nervous system has not yet been investigated in a "pure hypovolemia" model. The aim of the current study is therefore to investigate and describe the function of the autonomic nervous system prior to, during and after reduction of blood volume in healthy blood donors.

Inclusion Criteria:

• Volonteers eligable for blood donation following the Danish legislation
• Male
• Age 30-45
• Written informed consent
• Speak and understand Danish

Exclusion Criteria:

Volonteers not eligable for blood donation following the Danish legislation, among others due to:

• Alcohol and drug abuse
• Cognitive dysfunction
• Use of anxiolytic or antipsychotic drugs
• Arrhythmias or heart failure
• Diabetes mellitus type I
• Diabetes mellitus type II
• Use of opioids
• History of following diseases in the autonomic nervous system: Parkinson disease, multiple sclerosis, autonomic neuropathies
• History of cerebral apoplexy or transitory cerebral ischemia
• Dementia
• American Society of Anesthesiologists (ASA) score ≥ 4

Furthermore:

• History of orthostatic intolerance and/or orthostatic hypotension
• Use of following vasodilator antihypertensive drugs: beta-blockers, angiotensin converting enzyme inhibitors (ACEI), angiotensin 2 receptor blockers (ARBs), calcium channel blockers
• Use of loop diuretics, thiazid diuretics and potassium-sparing diuretics