title: A physiologic reduced oxygen protocol decreases the incidence of threshold retinopathy of prematurity.
abstract: OBJECTIVE
  To report the incidence of threshold retinopathy of prematurity (ROP) in very low birth weight premature infants from three neonatal intensive care units (NICUs) before and after implementation of a physiologic reduced oxygen protocol (PROP).
  
  
  METHODS
  PROSPECTIVE, OBSERVATIONAL STUDY OF DATA FROM THREE NICUS: Cedars-Sinai Medical Center (CSMC), Los Angeles; Good Samaritan Hospital (GSH), Los Angeles; and National University Hospital (NUH), Singapore. PROP was implemented to keep oxygen saturation values by pulse oximeter (SpO2) between 83% and 93% (as described in Pediatrics 2003;111:339-345). The incidence of threshold ROP in the year before and the year after implementation of PROP was compared. Data from the transition year were not included in the analysis.
  
  
  RESULTS
  THE INCIDENCE OF THRESHOLD ROP DECREASED IN EACH CENTER: CSMC, 3.3% to 0.0% (3/92 to 0/88); GSH, 14.8% to 4.9% (8/54 to 2/41); and NUH, 6.7% to 0.0% (3/45 to 0/30). Overall, the incidence of threshold ROP decreased from 7.3% to 1.3%. (P <.05). The 95% confidence interval was 4.3% to 12% for the pre-PROP group and 0.05% to 4.76% for the post-PROP group.
  
  
  CONCLUSIONS
  Physiologic hypoxia is the normal fetal state. Exposure of newborn premature infants to hyperoxia down-regulates retinal vascular endothelial growth factor. This arrests the normal retinal vascular migration and causes vaso-obliteration, the first phase of ROP. The hypothesis is that maintaining SpO2 values between 83% and 93% in the immediate postgestation life, combined with strict control of oxygen fluctuations, prevents the early vaso-obliterative phase and subsequent development of severe ROP. Significant reduction of threshold disease after implementation of PROP in all three centers supports the hypothesis.
authors.affiliation: Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Wright
authors.forename: David
authors.initials: D
authors.lastname: Sami
authors.forename: Lisa
authors.initials: L
authors.lastname: Thompson
authors.forename: Rangasamy
authors.initials: R
authors.lastname: Ramanathan
authors.forename: Roy
authors.initials: R
authors.lastname: Joseph
authors.forename: Sonal
authors.initials: S
authors.lastname: Farzavandi
mesh_terms: D002985:Clinical Protocols; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal / Q000639:trends; D010092:Oximetry; D010100:Oxygen / Q000008:administration & dosage*; D010101:Oxygen Consumption; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011446:Prospective Studies; D012178:Retinopathy of Prematurity / Q000453:epidemiology* / Q000517:prevention & control / Q000601:surgery
chemical_list: D010100:Oxygen