Measurement of plasma volume in neonates.

Abstract

There is no reliable and safe method for measuring plasma volume in ill newborn infants. We describe an adaptation of the dye dilution technique using indocyanine green as the plasma label, which can be used in the sickest and smallest of infants with the minimum of disturbance. To avoid the need to take large volumes of blood from the infant, samples were diluted 1:1 with distilled water and pooled adult sera was used to construct the dye dilution standard curves. Eighteen preterm and fullterm infants were studied on 30 occasions. The measured plasma volume ranged between 21-4 and 106 ml/kg. Paired measurements were performed within 30-90 minutes of each other in seven infants. In five infants estimations of plasma volume were made shortly before and 30 minutes after the infusion of a known quantity of plasma. In eight out of 12 infants who had two measurements made there was close agreement between the second measured volume and the first measured volume, taking into account how much plasma had been given to or taken from the infant between the two measurements. The error ranged from 0-2 to 5-2 ml and the plasma recovery error ranged from -2-9% to +4-7%. In the remaining four infants the errors ranged from 2-1 to 9-5 ml and -14-2% to +8-8%. Errors in the measurement of plasma volume may arise as the result of sampling too early before full mixing of the dye has occurred, and there is a potential error in the measurement due to the distribution of albumin in the extracellular space in sick infants resulting in an overestimation of the plasma volume. Proposals for reducing sources of errors are discussed.

A New Method for the Measurement of Cerebral Blood Volume and Total Circulating Blood Volume Using Near Infrared Spatially Resolved Spectroscopy and Indocyanine Green: Application and Validation in Neonates

“…It is firmly bound to plasma proteins, excreted in bile in unconjugated form, and rapidly eliminated by the liver within 10 -15 min. ICG has been shown to be safe in adults (27) and when used in newborn and preterm infants (4,8).…”

“…The availability of a simple cotside method to estimate TCV that could be used shortly after birth would be a useful tool both for the neonatal clinician and the researcher. Methods used previously involving the injection of autologous red cells labeled with biotin (3) or repeated blood sampling following injection of a marker such as indocyanine green (4) are not suitable for routine clinical practice.…”

Quantitative Near Infrared Spectroscopy Measurement of Cerebral Hemodynamics in Newborn Piglets

“…Furthermore, ICG results in much higher signalto-noise ratio data than does manipulation of SaO 2 . ICG has been used to measure various physiologic parameters such as cerebral blood flow (11), hepatic function (24), plasma volume (25), cardiac output (26), and left-to-right shunts (27) in infants since 1965. One study, involving more than 3000 human subjects, showed that i.v.…”

Blood Volume Assessment with Hemoglobin Subtype Analysis in Preterm Infants

“…Volume Determination with ICG PV was assayed and RCV calculated as described by Anthony et al [1], using an ICG solution of 0.25 mg/l. 0.2 mg/kg of ICG was administered as a rapid intravenous injection (over 10 s), and three blood samples (0.5 ml) were obtained at 3, 5 and 7 min after the injection.…”

“…Albumin-binding dyes indocyanine green [1] and Evan's blue [2][3][4] and partial plasma exchange transfusion [5] have previously been applied to assess neonatal PV. These techniques are impractical for most clinical purposes.…”