Stochasticity of flow through microcirculation as a regulator of oxygen delivery

OBJECTIVE: Observations of microcirculation reveal that the blood flow is subject to interruptions and resumptions. Accepting that blood randomly stops and resumes, one can show that the randomness could be a powerful means to match oxygen delivery with oxygen demand. METHOD: The ability of the randomness to regulate oxygen delivery is based on two suppositions: (a) the probability for flow to stop does not depend on the time of uninterrupted flow, thus the number of interruptions of flow follows a Poisson distribution; (b) the probability to resume the flow does not depend on the time for flow being interrupted; meaning that time spent by erythrocytes at rest follows an exponential distribution. Thus the distribution of the time to pass an organ is a compound Poisson distribution. The Laplace transform of the given distribution gives the fraction of oxygen that passes the organ. RESULT: Oxygen delivery to the tissues directly depends on characteristics of the irregularity of the flow through microcirculation. CONCLUSION: By variation of vasomotion activity it is possible to change delivery of oxygen to a tissue by up to 8 times.