Changes in blood and plasma volumes during growth

Abstract

Plasma and blood volumes of children and young adults are related to weight, surface area, and height by linear, exponential, and power functions. Over the entire growth period the best predictions of blood and plasma volumes were obtained from height by an exponential equation. Adequate estimates of blood volume were also obtained by those power and linear functions which related volumes to weight or surface area. The mild hypoxia associated with residency at moderate altitude (1,600 M.) did not elevate hematocrit levels in normal prepubertal boys as it did in adult males. Indirect evidence suggests that plasma and blood volumes of normal children expand significantly within 10 to 15 minutes after lying down. Plasma and blood volumes of children and young adults are related to weight, surface area, and height by linear, exponential, and power functions. Over the entire growth period the best predictions of blood and plasma volumes were obtained from height by an exponential equation. Adequate estimates of blood volume were also obtained by those power and linear functions which related volumes to weight or surface area. The mild hypoxia associated with residency at moderate altitude (1,600 M.) did not elevate hematocrit levels in normal prepubertal boys as it did in adult males. Indirect evidence suggests that plasma and blood volumes of normal children expand significantly within 10 to 15 minutes after lying down.