Related Experiment Video
Updated: Oct 9, 2026
Assessment of Vascular Function in Patients With Chronic Kidney Disease
Published on: June 16, 2014
The effect of moderate hypovolaemia on microcirculation in healthy older blood donors
K Janetzko1, H Klüter, H Kirchner
1Institute of Transfusion Medicine and Clinical Immunology, Red Cross Blood Service of Baden-Württemberg, Faculty of Clinical Medicine Mannheim, University of Heidelberg, Germany. k.jantzko@blutspende.de
Compensation for acute blood loss requires cardiovascular integrity. In older people, asymptomatic cardiovascular impairment is common. In these subjects, even moderate blood loss is often treated by external volume replacement although its benefits are not clear. We investigated the effect of 450 ml of blood loss on the microcirculation and compensatory mechanisms in healthy older blood donors. Red blood cell count, plasma viscosity and protein concentration were measured. Plasma volume replacement was calculated using haematocrit. We measured microcirculation tissue perfusion by laser Doppler fluxmetry prior to, during and after blood donation. Blood loss was immediately accompanied by a median rapid water shift of 208 ml (interquartile range 134-298 ml). Haemodilution led to a decrease in haematocrit, protein and plasma viscosity. We observed no changes in cutaneous microcirculation. Moderate blood loss is tolerated in older cardiovascularly asymptomatic patients without having an impact on microcirculation. This may reduce the need for external volume replacement.
Compensation for acute blood loss requires cardiovascular integrity. In older people, asymptomatic cardiovascular impairment is common. In these subjects, even moderate blood loss is often treated by external volume replacement although its benefits are not clear. We investigated the effect of 450 ml of blood loss on the microcirculation and compensatory mechanisms in healthy older blood donors. Red blood cell count, plasma viscosity and protein concentration were measured. Plasma volume replacement was calculated using haematocrit. We measured microcirculation tissue perfusion by laser Doppler fluxmetry prior to, during and after blood donation. Blood loss was immediately accompanied by a median rapid water shift of 208 ml (interquartile range 134-298 ml). Haemodilution led to a decrease in haematocrit, protein and plasma viscosity. We observed no changes in cutaneous microcirculation. Moderate blood loss is tolerated in older cardiovascularly asymptomatic patients without having an impact on microcirculation. This may reduce the need for external volume replacement.
Related Concept Videos
01:24Blood Pressure Imbalances and Circulatory Shock
Blood Pressure: Hypertension and Hypotension
Normal blood pressure is 120/80 mm Hg. Elevated blood pressure is 120-129/under 80 mm Hg. Hypertension, warranting treatment at 130/80 mm Hg, is often asymptomatic and can lead to severe cardiovascular events, aneurysms, peripheral arterial disease, chronic renal disease, or cardiac...
01:00Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Distribution
01:17Autoregulation of Blood Flow
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.
01:28Factors affecting Blood pressure
Physiological Factors:
01:30Alterations in Blood Pressure
Hypertension (High blood pressure)
Hypertension occurs when blood pressure readings consistently exceed the normal range. It is diagnosed when systolic blood pressure (the top number, indicating pressure while the heart beats)...