Respiratory Severity Score with Regard to Birthweight during the Early Days of Life for Predicting Pulmonary Hypertension in Preterm Infants

Abstract

Objective The respiratory severity score (RSS) has been demonstrated to be associated with the oxygenation index in intubated newborn infants. We aimed to evaluate the usefulness of RSS with regard to birthweight (BW) in preterm infants for predicting an association with future pulmonary hypertension (PH). Methods Preterm infants with <30 weeks’ gestation and <1250 g BW were reviewed and grouped into two (PH vs. no PH). Basic perinatal characteristics, comorbidities and parameters reflecting lung condition, including duration of invasive mechanical ventilator care, were compared. Respiratory support parameters (FiO2, RSS and RSS/kg) during the first 5 days of birth (0–120 h) were compared between the groups, and receiver operating characteristics curves were produced to evaluate the association with PH. Results RSS/kg, of the three respiratory support parameters, demonstrated significantly higher values in the PH group in the early days of life. Particularly, RSS/kg at day 2 of life had the greatest area under the curve [0.762, 95% confidence interval (CI) 0.655–0.869, p < 0.001] and maintained statistical significance [odds ratio (OR) 1.352, 95% CI 1.055–1.732, p = 0.017] in the multivariable analysis for a potential association with PH, along with gestational age (OR 0.996, 95% CI 0.993–0.999, p = 0.015) and preterm premature rupture of membrane >18 h (OR 4.907, 95% CI 1.436–16.765, p = 0.011). Conclusion RSS/kg is a potential marker associated with the development of PH. Future studies could verify its usefulness as a reliable surrogate for predicting respiratory morbidity in clinical settings.

Relationship Between the Respiratory Severity Score and Extubation Failure in Very-low-birth-weight Premature Infants

“…[ 18 , 19 ] Furthermore, several studies have shown its predictive value for mortality, BPD, and other short-term morbidities. [ 20 , 21 , 23 ] Mhanna et al . [ 22 ] investigated the utility of RSS for predicting extubation readiness in very-low-birth-weight infants and found that it was the only statistically significant risk factor for extubation failure.…”

“…[ 22 ] A study in which the RSS was analyzed by weight (RSS/kg) found that RSS/kg was more useful for predicting the development of pulmonary hypertension than the RSS. [ 23 ]…”

Respiratory Severity Score and Its Association with Adverse Outcomes in Extremely Low Birth Weight Infants Undergoing Invasive Mechanical Ventilation

“…Additionally, the same MAP value should lead to various effect sizes in different lungs. For example, Seo YM et al (18) pointed out the fact that a MAP of 10 cmH 2 O would lead to differential effects in the lungs of an infant with a birth weight of 500 g and in the lungs of an infant with a birth weight of 1000 g and calculated RSS as well as RSS/kg in the first 5 days of life in their study that intended to investigate the relationship between the development of pulmonary hypertension and RSS. They also found elevated RSS only on days 2 and 4, while RSS/kg was increased throughout the whole 5-day period.…”

“…Previous studies on RSS have established the ease of use, predictive value for morbidity and mortality, as well as utility in the early phases of life, for this scoring tool. However, most of these studies followed a singlecenter approach, involving patients managed within that center following labor (15,16,18,26,32). In this regard, our study differs from these previous investigations, as it was a multi-center study and included referrals from other centers within the first 6 hours of life.…”

“…Further areas of previous research include the role of RSS in preparation for extubation as well as in the prediction of BPD, mortality, and short-term complications (15)(16)(17). Also, it has been found that RSS/kg is correlated more closely with pulmonary hypertension than RSS alone (18).…”