To the Editor,
With time, the incidence and burden of retinopathy of prematurity (ROP) have been increasing due to increased survival of preterm babies as a result of better neonatal care and low coverage of screening and treatment. It can be catastrophic in developing countries hence it is important to catch the bull at the earliest. Among risk factors, prolonged use of higher supplemental oxygen is the most frequently identified factor for severe ROP. Despite several studies, the ideal range of oxygen saturation targets remains controversial. This was a prospective cross-sectional study conducted among 64 premature neonates of gestational age <36 weeks who were on oxygen and admitted in the neonatal intensive care unit from November 2019 to October 2021 after obtaining ethical clearance and was according to the Declaration of Helsinki guidelines. Informed written consent was signed. We compare the effect of two oxygenation strategies (86%–90% vs. 91%–94%) on the development of ROP in two groups (32 neonates). A brief clinical history and retinal examination were done and the finding was noted on a predesigned proforma. All neonates were screened according to Rashtriya Bal Swasthya Karyakram guidelines by one examiner. The data were analyzed using SPSS is a statistical software suite developed by IBM (Aligarh, Uttar Pradesh, India). P < 0.05 was taken as significant. Our study comprises 64 premature babies out of which 38 (59.4%) were male and 26 (40.6%) were female. The mean birth weight of babies was 1447.18 ± 288.38 g (range: 660–2280 g) and the mean gestational age of babies was 223.27 ± 16.25 days (range: 190–252 days) [Table 1]. Eighteen (28.12%) were delivered normally and 46 (71.87%) were delivered by cesarean section. Among 64 babies, 32 babies (86%–90%), 5 babies had developed ROP, and the remaining 32 babies (91%–94%), 14 babies had developed ROP. We observed a significant relationship between oxygen supplementation and the development of ROP (P = 0.014) [Table 2]. Our study was supported by Benefits of Oxygen Saturation Targeting Study II (BOOST–II)[1] and Hartnett and Lane.[2] In our study, oxygen saturation was measured by the pulse oximeter. We could find an accurate measurement of oxygen concentration and its fluctuation by means of a probe which gives us precise information about oxygen saturation and further implementation of controlled supplemental oxygen therapy. In our study, the mean duration of oxygen exposure was 16.78 ± 7.85 days in babies who had ROP and 9.22 ± 5.89 days in babies who did not developed ROP. We observed a significant relationship with P = 0.000 [Table 3]. Results were supported by Ashton et al.[3] Therefore, neonatologists should try to wean off supplemental oxygen as early as possible. In conclusion, we know that higher supplemental oxygen was found to be an important risk factor. Hence, an optimum oxygen saturation range which balances ROP risks and saves the life of babies is mandatory. We feel that a large-scale community-based study with long-term follow-up is warranted to confirm the outcomes of lower oxygen saturation in terms of morbidity and mortality.
Table 1.
Demographic data of the enrolled babies
| n | Minimum | Maximum | Mean±SD | |
|---|---|---|---|---|
| Gestational age (days) | 64 | 196 | 252 | 229.25±14.73 |
| Birth weight (g) | 64 | 660 | 2280 | 1554.21±367.92 |
SD: Standard deviation
Table 2.
Association between oxygen saturation given at birth and retinopathy of prematurity
| Range (%) | ROP |
Total | χ 2 | df | P | ||
|---|---|---|---|---|---|---|---|
| Present | Absent | ||||||
| Oxygen saturation | 86–90 | 5 | 27 | 32 | 6.063 | 1 | 0.014 |
| 91–94 | 14 | 18 | 32 | ||||
ROP: Retinopathy of prematurity
Table 3.
Association between duration of oxygen given and retinopathy of prematurity
| ROP | n | Mean±SD (days) | df | P | |
|---|---|---|---|---|---|
| Duration of oxygen given (days) | Present | 19 | 16.78±7.85 | 62 | 0.000 |
| Absent | 45 | 9.22±5.89 |
ROP: Retinopathy of prematurity, SD: Standard deviation
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
Acknowledgment
I feel privileged to express my deep sense of veneration for my co-authors AM, AN, and WA for their constant support and guidance in this study throughout my research period.
References
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