Evidence continues to accumulate that suggests that maintaining lower oxygen saturations in VLBW infants particularly during the acute phase of their immaturity (first 4 to 8 weeks of life) may decrease the incidence of vision-threatening ROP.  The literature also suggests that repeated episodes of alternating hypoxia and hyperoxia may exacerbate retinal injury.

Although definitive data are not yet available, Vanderbilt’s policy will be to target O₂ saturations of 85– 93% in babies on oxygen.

The low alarms on pulse oximeters should be set at 80%, the high alarms on the pulse oximeters should be set at 95% for infants < 33 weeks gestation.

Nurses and physicians are asked not to “chase” SaO2 with rapid changes in FiO2 to avoid under- and over-shooting leading to alternating hypoxia and hyperoxia.  Brief periods of desaturation or oversaturation should be tolerated with observation only; longer periods of saturations outside of the target range should lead to evaluation and correction of underlying problem with possible re-adjustment of the FiO2.  After delivery and the acute phase of HMD necessitating surfactant treatment (when FiO2 needs may change quite rapidly), changes in FiO2 from a baby’s established baseline oxygen requirement should be made slowly in small increments, again to avoid swings from hyperoxia to hypoxia and back again.

Obviously, some patients will have medical reasons to target O₂ saturations outside of this range.  For example, physicians may desire higher O₂ saturations in the term baby with PPHN or lower saturations in the infant with cyanotic congenital heart disease.  Furthermore, physicians may want to target slightly higher O₂ saturations in the older preterm infant with recurrent apnea or growth failure.  For these exceptions, physicians should specify the desired O₂ saturations and pulse oximeter alarm limits in the orders.

Of note, babies with a clinical diagnosis of PDA receiving supportive care or indomethacin therapy should have their pulse ox alarm limits reset to target O₂ saturations of 92-98%.  Consistently maintaining maximal safe oxygenation will facilitate closure of the ductus.

Also, some patients will saturate 98 – 100% on room air. Infants who are not receiving supplemental oxygen may have their high alarm limits reset to 100% as they are not at risk for hyperoxic exposure.

 Once an infant reaches 33 weeks CGA, the oxygen needs and target will be reassessed.  Alarm limits should be raised to 85 - 98% with a target of 88-97%.  Prior to discharge, the baby should maintain saturation of >92% at all times.

Reference:

Chow LC, et al. Can changes in clinical practice decrease the incidence of severe retinopathy of prematurity in very low birth weight infants? Pediatrics 2003;111:339-345.

Tin W et al. Pulse oximetry, severe retinopathy, and outcome at one year in babies of less than 28 weeks gestation. Arch Dis Child Fetal Neonatal Ed 2001; 84: F106-10.

Penn JS, et al. The range of PaO2 variation determines the severity of oxygen-induced retinopathy in newborn rats. Invest Ophthalmol Vis Sci 1995; 36: 2063-2070.

Askie LM, Henderson-Smart DJ. Restricted versus liberal oxygen exposure for preventing morbidity and mortality in preterm or low birth weight infants.  Cochrane Systematic Reviews. http://www.nichd.nih.gov/cochraneneonatal/askie4/askie.HTM

Resolved at Clinical Division Meeting 12/17/01. Revisited at the Nursery Policy & Procedure Meeting 4/17/02.  Revisited again at Journal Club 2/25/03.