The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts

HOW DOES A CHANGE IN OXYGEN SUPPLIMENTATION AFFECT THE INCIDENCE OF RETINOPATHY OF PREMATURITY?

Jonathan E. Sears2, Christine Sonnie2, David M. Dolcini1, Jeffrey T. Pietz3



Background: The development of ROP has been linked to levels of oxygen exposure in premature infants. We compared the change in incidence of ROP in a Level III NICU before and after a protocol change in standards for oxygen use.

Methods:
An IRB approved database was established to record the gestational age (GA), birth weight (BW), Stage and Zone of ROP, date of exam, maternal characteristics, and infant morbidity/mortality. A retrospective analysis was performed between September 2005 and October 2007. First year exams were performed on infants with standard oxygen use (saturations >95%); the second year exams were performed on infants with strict monitoring (saturations 87-92% <34 weeks and 92-97% > 34 weeks). A non-randomized interventional study was undertaken on infants < 1500 grams birth weight; or < 32 weeks GA or more than 24 hours of oxygen therapy. Zone I eyes were treated with diode laser indirect ophthalmoscopy if any ROP plus disease was noted. Zone 2 and 3 eyes were treated as standard threshold per CRYO-ROP study. The main outcomes measured were prevalence of ROP, Stage and Zone of retinopathy, threshold, and progression to retinal detachment or fold.

Results:
190 patients were examined between September 2005 and October 2007. 98 were examined before and 92 after the changes were implemented. 173 and 139 exams were performed on these patient cohorts, respectively. Not only did the overall incidence of ROP dramatically decrease from 35% to 13% (p.001) after the oxygen standards were changed, but there was a decrease in the incidence of pathologic stages of ROP. Stage 3 disease decreased from 11% to 2% (p=.021); threshold disease, the stage at which laser ablation is used, decreased from 7% to 1% (p=.066). We also found an increase in Stage 0 (immature vessels) after the changes were implemented. Matching the stage 0 increase was an increase in Zone 3 and a decrease in less mature zones, implying that the retina tended to develop at a quicker rate within the new oxygen parameters. A comparison of associated co morbidities (RDS, PVL, sepsis, NEC, PDA, steroids for CLD), maternal characteristics (outborn birth, prenatal care, antenatal steroids, C-section, ethnicity), and mortality was not statistically significant between groups.

Conclusions:
Meticulous control of oxygen with lower oxygen targets at early gestational age and higher oxygen limits at older gestational age significantly decreases the severity and prevalence of ROP.