Nucleated Red Blood Cell Counts Differentiate Cardiac from Respiratory Causes of Cyanosis at Birth

This study assesses the utility of nRBC as a marker to differentiate hypoxia due to CHD vs RD in term neonates. This was a single-center, retrospective study of term neonates with cyanosis from 2015 to 2022. Neonates  <  37 weeks of gestation, with hypoxic-ischemic encephalopathy, and those with other causes of cyanosis were excluded. The patients were divided into 2 groups: cyanotic CHD and cyanotic RD. Clinical and laboratory data done within 12 h and 24–36 h after birth were collected. Data are represente d as median and Interquartile range. Of 189 patients with cyanosis, 80 had CHD and 109 had RD. The absolute nRBC count at ≤ 12 h of age was lower in the CHD (360 cells/mm3) compared to RD group (2340 cells/mm3) despite the CHD group having significantly lower baseline saturations. A value of 1070 cells/mm3 was highly sensitive and specific for differentiating CHD from RD. The positive predictive value for this cut-off value of 1070 cells/mm3 was 0.94 and the negative predictive value was 0.89. The absolute nRBC is a simple screening test and is available worldwide. A nRBC  <  1070 cells/mm3 in cyanotic newborns should hasten the search for CHD etiology with the possible need for prostaglandin therapy.
Source: Pediatric Cardiology - Category: Cardiology Source Type: research