Lower pass threshold (≥93%) for critical congenital heart disease screening at high altitude prevents repeat screening and reduces false positives

Abstract

Objective We evaluated first screen pass rate for two pass thresholds for critical congenital heart disease (CCHD) oxygen saturation (SpO2) screening at higher altitude. Study design A retrospective cohort of 948 newborns underwent CCHD screening near sea-level (n = 463) vs 6250 ft altitude (n = 485) over 3 years. Standard SpO2 pass threshold ≥95% and lower SpO2 pass threshold ≥93% (high-altitude screen) were applied to first measurements to compare pass frequencies. Results The median SpO2 was lower in high-altitude newborns (96% vs 99%—p < 0.001). The high-altitude newborns passed the AAP algorithm first screen less often (89.3% vs 99.6%—p < 0.001). With the high-altitude algorithm, 98% of high-altitude newborns passed the first screen. Conclusion Lowering the SpO2 pass threshold by 2% at >6000 ft, significantly increased first screen pass rate. Adjustments for altitude may reduce nursing time to conduct repeat measurements and prevent transfers for echocardiograms. Larger studies are necessary to assess impact on false negatives.

Machine Learning–Based Critical Congenital Heart Disease Screening Using Dual‐Site Pulse Oximetry Measurements

“… 11 In fact, most patients do not require the potential second screen, as the majority either pass or fail the test with a single measurement. 29 In the ML‐based algorithm, the second measurement would occur before 24 hours of age, theoretically enhancing the potential for early diagnosis.…”

Trajectories of oxygen saturation within 6–72 hours after birth in neonates at moderate altitude: a prospective longitudinal cohort study

“…This again highlights the importance of adopting an altitude-suited SpO 2 threshold value for screening [ 26 ]. Relative to the mean SpO 2 of 98.5% at sea level, SpO 2 around 24 hours of age at 1600–1900 m was lower and ranged from 93.0% to 97.2% [ 9 , 16 , 27 – 32 ]. Our mean SpO 2 values of 95%–96% agreed with most of the prior studies [ 9 , 27 , 28 , 30 , 31 ], and we took advantage of repeated measurements with a motion-resistant pulse oximeter and a double-check procedure, thus largely minimizing the detection errors.…”

“…There are also uncertainties regarding the threshold values for CCHD screening or initiation of oxygen treatment [ 3 ]. Although lower threshold values of 90%–93% SpO 2 have been used, they are selected experientially rather than derived from empirical data, which would be ideal [ 14 – 16 ]. Without knowing how precisely SpO 2 changes over time, it is difficult to justify the optimal timing and low limits for identifying hypoxemic diseases.…”