Association between Red Blood Cell Distribution Width and the Speed of Adding Milk with Non- invasive Positive Pressure Ventilation Mode in Preterm Infants

Abstract

Background Non-invasive positive pressure ventilation (NIPPV) is applied in the early postnatal period in most preterm infants; however, whether it slows down milk addition speed remains debatable. Elevated red blood cell distribution width (RDW) causes gastrointestinal ischemia and enteral feeding risks. This study aimed to explore the relationship between RDW and the speed of adding milk in NIPPV mode (SAMNIPPV) in preterm infants during hospitalization. Methods Between 01/05/2022 and 30/11/2022, 110 preterm infants (gestational age < 32 weeks, birth weight < 1500 g) treated with NIPPV were included to calculate the speed of milk addition. RDW was extracted from the complete blood count results during hospitalization. Univariate and multivariate logistic regression analyses identified the association between RDW and SAMNIPPV. Results Low (15.1 ± 0.6%), mid (16.6 ± 0.4%), and high (19.0 ± 1.2%) RDW were observed in 37, 36, and 37 infants, respectively. The mean SAMNIPPV decreased with increasing RDW during hospitalization. Compared to the high SAMNIPPV group, the tripartite RDW levels in the low and mid SAMNIPPV groups differed significantly. Univariate analysis showed a reduction in the SAMNIPPV (2.1 mL/kg/d) when RDW was 16.9 ± 1.8%; both high and mid RDW were risk factors for low SAMNIPPV. In multivariate analysis, high RDW (19.0% ±1.2%) during hospitalization was a risk factor for low SAMNIPPV and determined as the predictive cut-off value for preterm infants with low SAMNIPPV. Conclusions An elevated RDW was associated with reduced speed of milk addition in preterm infants treated with NIPPV. Milk addition should be closely monitored when RDW is > 19.0 ± 1.2% during hospitalization as it significantly decreased the SAMNIPPV by 4.4 mL/kg/d.