Measuring circulating blood volume in newborn infants using pulse dye densitometry and indocyanine green.
BACKGROUND
Circulating blood volume (BV) is an important, but often unconsidered, variable in newborn infants undergoing intensive care. The data on validation and repeatability of BV measurement are limited.


OBJECTIVE
To validate and test the repeatability of measuring BV in newborn infants using indocyanine green (ICG) and pulse dye densitometry (PDD).


METHODS
Validation--Paired measurements of BV were made using the fetal hemoglobin (HbF) dilution and the PDD method. Repeatability--The BV was measured twice at an interval of 30-40 min in a second group of infants.


RESULTS
Validation--Data from three of 13 infants studied were excluded because of probe dislodgement or ICG injection error. The median (range) birth weight of the 10 infants whose data were analyzed was 1032 g (740-2384 g) and seven (70%) were receiving either mechanical ventilation or nasal CPAP. The median BV measured by HbF dilution was 66.2 ml x kg(-1) (43.7-81.0 ml x kg(-1)) and by the PDD method was 68.9 ml x kg(-1) (49.3-101.0 ml x kg(-1)). The mean difference was 5.92 ml x kg(-1) (SD 17.33 ml x kg(-1)). Repeatability--Twelve infants were studied and three excluded because of probe dislodgement/motion artifact or ICG injection error. The median weight of the nine infants whose data were analyzed was 1208 g (795-2600 g). The median (range) BV1 and BV2 were 70.5 ml x kg(-1) (53.1-160 ml x kg(-1)) and 87.5 ml x kg(-1) (38.0-248.0 ml x kg(-1)), respectively. Mean difference of the two BV estimates (BV1-BV2) was -24.6 ml x kg(-1) (SD 33.3 ml x kg(-1)) and coefficient of repeatability was 66.5 ml x kg(-1).


CONCLUSIONS
Pulse dye densitometry can be used to measure BV in the newborn infant at the cotside but the repeatability measurements suggest that its use is limited.
Aladangady
Narendra
N
Department of Child Health, Homerton University Hospital/Bart's and the London School of Medicine and Dentistry, London, UK.
Leung
Terence
T
Costeloe
Kate
K
Delpy
David
D
D001810:Blood Volume; D001811:Blood Volume Determination / Q000379:methods; D004396:Coloring Agents; D003720:Densitometry / Q000379:methods*; D005319:Fetal Hemoglobin / Q000032:analysis; D006801:Humans; D007208:Indocyanine Green; D007231:Infant, Newborn; D012107:Research Design / Q000592:standards
D004396:Coloring Agents; D005319:Fetal Hemoglobin; D007208:Indocyanine Green