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Early Haemoglobin Oxygen Affinity as a Hypothesis-Generating Marker for Retinopathy of Prematurity Risk in Preterm
1Department of Neonatology, Bağcılar Training and Research Hospital, Istanbul, Turkey.
Insights
Higher postnatal haemoglobin oxygen affinity (P50) in preterm infants is linked to retinopathy of prematurity (ROP). This finding suggests P50 may indicate impaired oxygen delivery, but it is not a reliable screening tool for ROP.
Area of Science:
- Neonatal physiology
- Ophthalmology
- Perinatal medicine
Background:
- Retinopathy of prematurity (ROP) is a significant cause of visual impairment in premature infants.
- Understanding physiological markers associated with ROP risk is crucial for early intervention.
- Haemoglobin oxygen affinity, measured as P50, reflects oxygen delivery to tissues.
Purpose of the Study:
- To determine if postnatal haemoglobin oxygen affinity (P50) in preterm infants is associated with the risk of developing ROP.
- To explore P50 as a potential physiological marker for ROP risk.
Main Methods:
- Retrospective cohort study of 232 preterm infants born before 32 weeks gestation.
- Daily calculation of haemoglobin P50 and lactate values during the first week of life.
- Logistic regression and ROC analysis to assess the association between P50 and ROP development.
Main Results:
- Infants who developed ROP had significantly higher Day 7 P50 values (26.9 mmHg) compared to those without ROP (26.1 mmHg).
- A Day 7 P50 greater than 26.4 mmHg was independently associated with ROP (OR 2.5).
- P50 was not predictive of Type 1 ROP, and lactate levels showed no association.
Conclusions:
- Elevated postnatal P50 may be modestly associated with ROP development in preterm infants.
- This association might reflect impaired oxygen delivery during critical early retinal vascularization.
- While not suitable for screening, P50 warrants further investigation as a physiological marker for ROP.
Purpose:
To investigate whether postnatal haemoglobin oxygen affinity (P50), derived from serial arterial blood gases, is associated with the risk of retinopathy of prematurity (ROP) in preterm infants, as a potential physiologic marker.
Study Design:
Retrospective cohort study.
Methods:
This study included 232 preterm infants born < 32 weeks gestation. Haemoglobin P50 and lactate values were calculated daily during the first week of life. The primary outcome was the development of any ROP; treatment-requiring (Type 1) ROP was a secondary endpoint. Associations were analysed using logistic regression and ROC analysis.
Results:
Infants who developed ROP had significantly higher Day 7 P50 values (mean 26.9 ± 1.8 mmHg) than those without ROP (26.1 ± 1.7 mmHg; p = 0.003). A Day 7 P50 > 26.4 mmHg was independently associated with ROP (OR 2.5; 95% CI 1.3-4.9), though predictive performance was modest (AUC 0.60). Lactate levels showed no association with ROP. P50 was not predictive of Type 1 ROP.
Conclusion:
Increased postnatal P50 may be modestly associated with ROP development, reflecting impaired oxygen delivery during early retinal vascularization. While not suitable for screening, P50 may serve as a physiologic marker warranting further mechanistic investigation.
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