The toxigen initiative: targeting oxygen saturation to avoid sequelae in very preterm infants

Effect of a Novel Oxygen Saturation Targeting Strategy on Mortality, Retinopathy of Prematurity, and Bronchopulmonary Dysplasia in Neonates Born Extremely Preterm

OBJECTIVE

To study the impact of an oxygen management strategy incorporating oxygen saturation (SpO₂) targeting and fraction of inspired oxygen monitoring on the incidence of retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), and mortality.

STUDY DESIGN

This retrospective cohort study analyzed the incidence of any ROP, severe ROP, ROP requiring treatment (surgery and/or bevacizumab), BPD, and mortality among 23-28 weeks of gestational age infants admitted to the neonatal intensive care unit in 3 epochs: Epoch 1 (2007-2010) before implementation of SpO₂ histograms; Epoch 2 (2012-2014), with development of a software tool capable of generating automatic bedside SpO₂ histograms; and Epoch 3 (2016-2019), with further software enhancements, incorporating simultaneous SpO₂ and fraction of inspired oxygen measurements.

RESULTS

During Epochs 1, 2, and 3, there were 601, 381, and 550 eligible infants, respectively, for a total of 1532 eligible infants. Mortality, any ROP, severe ROP, ROP needing treatment, and BPD all showed significant downward trends across the 3 epochs. The aOR of mortality was significantly lower in Epoch 3 compared with Epoch 1 (aOR 0.48). The aORs of any ROP and of BPD were significantly lower in Epochs 2 and 3 compared with Epoch 1 (respectively, ROP aORs 0.53 and 0.38; BPD aOR 0.43 and 0.43). The aOR of ROP needing treatment was significantly lower in Epoch 3 compared with Epoch 1 (aOR 0.43).

CONCLUSIONS

We have demonstrated improvement in rates of mortality, any ROP, ROP requiring treatment, and BPD after implementation of a novel oxygen management strategy.

A systematic review of reports of quality improvement for bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the most common morbidity of preterm infants, and its incidence has not responded to research and intervention efforts to the same degree as other major morbidities associated with prematurity. The complexity of neonatal respiratory care as well as persistent inter-institutional variability in BPD rates suggest that BPD may be amenable to quality improvement (QI) efforts. We present a systematic review of QI for BPD in preterm infants. We identified 22 reports from single centers and seven from collaborative efforts published over the past two decades. In almost all of the reports, respiratory QI interventions successfully reduced BPD or other key respiratory measures, particularly for infants with birth weight over 1000 g. Several themes and lessons from existing reports may help inform future efforts in both research and QI to impact the burden of BPD.

Improving manual oxygen titration in preterm infants by training and guideline implementation

To study oxygen saturation (SpO₂) targeting before and after training and guideline implementation of manual oxygen titration, two cohorts of preterm infants <30 weeks of gestation needing respiratory support and oxygen therapy were compared. The percentage of the time spent with SpO₂ within the target range (85-95%) was calculated (%SpO₂-wtr). SpO₂ was collected every minute when oxygen is >21%. ABCs where oxygen therapy was given were identified and analyzed. After training and guideline implementation the %SpO₂-wtr increased (median interquartile range (IQR)) 48.0 (19.6-63.9) % vs 61.9 (48.5-72.3) %; p < 0.005, with a decrease in the %SpO₂ > 95% (44.0 (27.8-66.2) % vs 30.8 (22.6-44.5) %; p < 0.05). There was no effect on the %SpO₂ < 85% (5.9 (2.8-7.9) % vs 6.2 (2.5-8) %; ns) and %SpO₂ < 80% (1.9 (1.0-3.0) % vs 1.7 (0.8-2.6) %; ns). In total, 186 ABCs with oxygen therapy before and 168 ABCs after training and guideline implementation occurred. The duration of SpO₂ < 80% reduced (2 (1-2) vs 1 (1-2) minutes; p < 0.05), the occurrence of SpO₂ > 95% did not decrease (73% vs 64%; ns) but lasted shorter (2 (0-7) vs 1 (1-3) minute; p < 0.004).

CONCLUSION

Training and guideline implementation in manual oxygen titration improved SpO₂ targeting in preterm infants with more time spent within the target range and less frequent hyperoxaemia. The durations of hypoxaemia and hyperoxaemia during ABCs were shorter. What is Known: • Oxygen saturation targeting in preterm infants can be challenging and the compliance is low when oxygen is titrated manually. • Hyperoxaemia often occurs after oxygen therapy for oxygen desaturation during apnoeas. What is New: • Training and implementing guidelines improved oxygen saturation targeting and reduced hyperoxaemia. • Training and implementing guidelines improved manual oxygen titration during ABC.

Compliance in oxygen saturation targeting in preterm infants: a systematic review

During oxygen therapy in preterm infants, targeting oxygen saturation is important for avoiding hypoxaemia and hyperoxaemia, but this can be very difficult and challenging for neonatal nurses. We systematically reviewed the qualitative and quantitative studies investigating the compliance in targeting oxygen saturation in preterm infants and factors that influence this compliance. We searched PubMed, Embase, Web of Science, Cochrane, CINAHL and ScienceDirect from 2000 to January 2015. Sixteen studies were selected, which involved a total of 2935 nurses and 574 infants. The studies varied in methodology, and we have therefore used a narrative account to describe the data. The main finding is that there is a low compliance in oxygen targeting; the upper alarm limits are inappropriately set, and maintaining the saturation (SpO2) below the upper limit presented particular difficulties. Although there is little data available, the studies indicate that training, titration protocols and decreasing workload could improve awareness and compliance. Automated oxygen regulations have been shown to increase the time that SpO2 is within the target range.

CONCLUSION

The compliance in targeting oxygen during oxygen therapy in preterm infants is low, especially in maintaining the SpO2 below the upper limit.

WHAT IS KNOWN

• The use of oxygen in preterm infants is vital, but the optimal strategyremains controversial. • Targeting SpO2 during oxygen therapy in preterm infants has beenshown to reduce mortality and morbidity.

WHAT IS NEW

• Review of the literature showed that the compliance in targeting SpO2and alarm settings is low. • Creating awareness of risks of oxygen therapy and benefits in targeting,decreasing nurse/patient ratio and automated oxygen therapy couldincrease compliance.

Oxygen saturation limits and evidence supporting the targets

Supplemental oxygen use in the preterm infant is required for survival. Evidence supports a narrow therapeutic window between the helpful and harmful effects of supplemental oxygen in this vulnerable population. The clinical question was-what are the recommended oxygen saturation targets for the preterm infant and the preterm infant corrected to term? Multiple databases were searched for published research in English from 2008 to 2014 using key search terms. A total of 18 articles met inclusion criteria. Early neonatal research linked high levels of supplemental oxygen with retinopathy of prematurity and blindness. Years later, correlations between high arterial oxygen levels and oxidative stress leading to pulmonary and/or neurologic insults were established. Three large multicentered, international studies have recently been published (BOOST II, COT, and SUPPORT), which support oxygen saturation target ranges of 87% to 94% until vascular maturation of the retina is achieved. Two of the 3 studies reported a significant correlation between low saturation limits (85%-89%) and death in the extremely preterm population. Identified best care strategies to prevent states of hypoxia and/or hyperoxia include establishing clear target saturation limits according to recommendations, which are supported by the multidisciplinary team, adequate nurse to patient ratio, improve knowledge deficits, improve bedside compliance, and finally visual cues to remind caregivers of target saturation ranges.

The risk for hyperoxaemia after apnoea, bradycardia and hypoxaemia in preterm infants

OBJECTIVE

To investigate the occurrence and duration of oxygen saturation (SpO₂) ≥95%, after extra oxygen for apnoea, bradycardia, cyanosis (ABC), and the relation with the duration of bradycardia and/or SpO₂ ≤80%.

METHODS

All preterm infants <32 weeks' gestation supported with nasal continuous positive airway pressure (nCPAP) admitted to our centre were eligible for the study. We retrospectively identified all episodes of ABCs. In ABCs where oxygen supply was increased, duration and severity of bradycardia (<80 bpm), SpO₂ ≤80%, SpO₂ ≥95% and their correlation were investigated.

RESULTS

In 56 infants, 257 ABCs occurred where oxygen supply was increased. SpO₂ ≥95% occurred after 79% (202/257) of the ABCs, duration of extra oxygen supply was longer in ABCs with SpO₂ ≥95% than without SpO₂ ≥95% (median (IQR) 20 (8-80) vs 2 (2-3) min; p<0.001)). The duration of SpO₂ ≥95% was longer than bradycardia and SpO₂ ≤80% (median (IQR) 13 (4-30) vs 1 (1-1) vs 2 (1-2) min; p<0.001). SpO₂ ≥95% lasted longer when infants were in ambient air than when oxygen was given before the ABC occurred (median (IQR)15 (5-38) min vs 6 (3-24) min; p<0.01).

CONCLUSIONS

In preterm infants supported with nCPAP in the neonatal intensive care unit (NICU), SpO₂ ≥95% frequently occurred when oxygen was increased for ABCs and lasted longer than the bradycardia and SpO₂ ≤80%.