Estimation of extracellular fluid volume by bromide dilution in infants less than 1000 grams birth weight

We measured extracellular fluid volume by bromide dilution within 12 h of birth in 32 infants less than 1000 g birth weight. Mean (+/- S.D.) birth weight and gestational age were 763 +/- 123 g and 26 +/- 1 week, respectively. Mean extracellular fluid volume was 360 +/- 86 ml (477 +/- 107 ml/kg). These results are similar to extracellular fluid volume estimates from previous carcass analysis data. Wide variability is observed with both methods suggesting that biologic variability may be important.