Altitude at Birth on Critical Congenital Heart Disease Screening Through Pulse Oximetry in Newborns in Colombia - A Validation by Experts

Critical Congenital Heart Diseases (CCHDs) are heart anomalies that if untreated within the first year of life, can lead to death. Current strategies for an early diagnosis involve fetal echocardiography and physical examination. However, these practices fail to diagnose more than 50% of the cases. Since most CCHDs are hypoxic, the use of pulse oximetry to measure arterial oxygen saturation (SaO2) is considered as a complementary method for their detection. Studies have reported that the combination of echocardiography, physical examination and pulse-oximetry increases CCHDs diagnosis in newborns (NBs). Pulse oximetry screening algorithms are affected by altitude, and in Colombia, with a population concentrated at 1,000-2,700 meters above sea level, specific cut-off points for oxygen saturation are necessary.A construction and validation of an algorithm that would detect CCHDs in NBs in a range of 0-2,700 meters was done, based on 1) scientific literature available on pulse-oximetry in NBs, 2) SaO 2 values reported at different altitudes, 3) Neonatology and Pediatric Cardiovascular Surgery experts’ opinion, and 4) assessment by the Colombian Society of Neonatology, Cundinamarca.A SaO 2 <90% cut-off point was defined, measured by pulse oximetry during the first 24 hours of life, or a difference >3% in measurements for saturation in hand and foot, with referral for chest X-ray and transthoracic echocardiogram in case of <90% readings. Combined with the physical examination, this strategy will allow early detection of CCHDs in NBs, and it may be used as basis for the design of public policies in the National screening panel.