The objective of our study was to evaluate the effect of race on the functional residual capacity (FRC) and pulmonary mechanics in VLBW singletons of 25-30 weeks of gestation. We studied 15 African American infants (mean BW=991 g; GA = 27.1 wks, 53% male, 50% treated with antenatal steroids (AS)) and 15 matched Caucasian infants (mean BW = 992g, GA=27.9 wks, 50% male, 50% treated with AS). FRC was measured with the nitrogen washout technique at 24 hours and one week of age. A minimum of two measurements were performed with the neonate supine and quiet. Only consistent tracings initiated at end expiration and without evidence of a leak were accepted. A study was acceptable if the measurements had a coefficient of variation <10%. Respiratory system compliance (Crs) was measured with the single breath occlusion technique (SensorMedics 2600). Values are mean ± SEM. FRC in ml/kg; Crs in ml/cmH2O/kg. Our preliminary findings demonstrate that by 7 days of age, VLBW singletons of African American origin have established a significantly increased FRC as compared to Caucasians matched for BW, GA, gender and AS therapy. We speculate that this increased lung volume may represent structural changes due to genetic differences.Table

Table 1
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