Early screening with pulse oximetry for the detection of critical cyanotic congenital heart defects. Diagnostic test study

Cyanotic critical congenital heart defects (CCHD) are severe malformations that manifest as cardiocirculatory collapse during the first month of life, with high mortality without timely treatment. Objective: To evaluate the performance of the American Academy of Pediatrics (AAP) protocol for the use of pulse oximetry for the early detection of critical congenital heart defects in neonates. Patients and Method: Prospective study of diagnostic tests in neonates older than 34 weeks and 2000 grams of birth weight between 6 to 48 hours of age, between August 2021 and January 2022. Clinical variables were collected from a review of medical records. Those with a prenatal history of CCHD detected by prenatal ultrasound were excluded. According to the AAP protocol, any saturation value less than 90% was considered a positive screening. The oximetry result was evaluated against a reference standard consisting of echocardiography or clinical follow-up. Results: A total of 609 neonates underwent pulse oximetry testing with a median of 15.4 hours of life; 6.9% of patients had a positive screening and underwent echocardiography. Outpatient follow-up was conducted on 520 neonates with a mean of 96 days of life. No patients with critical congenital heart disease were detected. Screening identified non-critical congenital heart diseases with a sensitivity of 70.7% (95% CI 55.6-85.9) and a specificity of 97.6% (95% CI 96.1-99.0). Conclusions: Most early screenings were true negatives during outpatient follow-up. A positive screening allowed for the identification of non-critical congenital heart disease detected by echocardiography or another cause of non-cardiac hypoxemia.