Plasma volume estimation in severely ill infants and children using a simplified Evans blue method

Area of Science:

• * Physiology
• * Pediatric Medicine
• * Clinical Chemistry

Background:

• * Accurate plasma volume measurement is crucial for managing critically ill patients, especially infants and children.
• * The Evans blue dye method offers a simplified approach compared to radioiodinated human serum albumin (RIHSA).

Purpose of the Study:

• * To evaluate the accuracy of a simplified Evans blue dye method for plasma volume determination.
• * To compare plasma volume measurements obtained by Evans blue dye and RIHSA in pediatric patients and newborn infants.

Main Methods:

• * Simultaneous measurement of plasma volume using Evans blue dye and 125iodinated human serum albumin (RIHSA).
• * Studies conducted on 8 newborn infants and 14 pediatric patients (6 months to 14 years) with severe circulatory disturbances.
• * Comparison of results between the two methods, including agreement, differences, and disappearance rates.

Main Results:

• * Plasma volumes measured by Evans blue and RIHSA agreed within +/-5% in 20 studies and +/-10% in all studies.
• * Evans blue method showed higher plasma volumes than RIHSA, significantly in newborn infants (+4.0+/-3.6%).
• * Evans blue exhibited faster disappearance rates than RIHSA, significantly in older children (+2.3+/-4.2%/h).

Conclusions:

• * The simplified Evans blue dye method is a reliable and accurate tool for measuring plasma volume in pediatric populations.
• * While generally accurate, slight overestimation by Evans blue in newborns and faster clearance in older children should be considered.