Oxygenation Instability and Short-Term Morbidities Among Very-Low-Birthweight Premature Infants

Abstract

Aim: Oxygenation instability is common among very-low-birthweight premature infants (VLBW) and is correlated with morbidities of prematurity. We aimed to study the association of oxygenation instability of VLBW premature infants during the first week of life, as documented by the SpO2 histogram, with short-term neonatal morbidities. Methods: VLBW infants requiring respiratory support were included. 24-h SpO2 histograms were documented once daily. A classification system, based on the distribution of the histogram, was used to classify the histograms into stable/unstable categories. Results: Seventy-seven infants with mean (SD) gestational age-28.5 (2.1) weeks and birth weight-1040 (243) g were included in our study. 2063 histograms were recorded. Mean (SD) length of follow-up-27.5 (20.1) days per infant. 62% of infants remained stable during the follow-up period, while 38% experienced instability. 52% entered the unstable period during the first week of life. These infants had a higher risk of bronchopulmonary dysplasia (BPD)/death after adjusting for gestational age (OR [95% CI] 17.5 [4.0, 77.2]; p < 0.001), and for a variety of demographic and clinical variables (OR [95% CI] 32.4 [2.5, 418.5]; p = 0.008). Conclusion: VLBW premature infants demonstrate a distinct instability pattern. Entry into the unstable phase during the first week of life is associated with BPD/death, making it a potential predictive tool. Hypoxemia burden during the first week of life is correlated with BPD or death, while iatrogenic hyperoxemia is not.