CCHD Pulse-Ox Screen

Algorithm

Screen 1 (age ≥24 h, room air; right hand = pre-ductal, foot = post-ductal)
  Any SpO2 <90% (hand or foot)                          -> FAIL
  Hand ≥95% AND foot ≥95% AND |hand - foot| ≤3%       -> PASS
  Otherwise (90-94% in hand or foot, OR difference >3%) -> REPEAT once in 1 hour

Screen 2
  Any SpO2 <90%                                         -> FAIL
  Hand ≥95% AND foot ≥95% AND |hand - foot| ≤3%       -> PASS
  Otherwise                                             -> FAIL (no third screen)

• Martin 2020 (expert panel) recommended two changes to the 2011 AAP algorithm: “requiring an oxygen saturation of at least 95% in both (formerly either) the upper and lower extremities to pass” and “requiring only 1 repeat screen instead of 2 for cases that neither pass nor fail initially” (abstract). The 2025 AAP clinical report (Oster 2025) endorsed this as the new AAP algorithm.
• The branch wording above follows the CDC summary of the AAP algorithm (fail: any measure <90% in either the right hand or foot on the initial or repeat screen; <95% in either on 2 measures; >3% difference on 2 measures, each separated by 1 hour; pass: ≥95% in both and ≤3% absolute difference) and the Tennessee Department of Health protocol that cites Martin 2020. The AAP figure itself was not retrieved for this prototype.
• The difference is absolute: a foot reading higher than the hand counts the same as a lower one (as in the CDC wording, “≤3% absolute difference”).
• Published example (Tennessee protocol): “a 96% in the foot and 100% in the hand after one repeat would fail”. This page gives the same answer.
• One edge case: a first screen that is borderline only because of a >3% difference, followed by a repeat with both values 90–94% and no difference, meets neither CDC “2 measures” rule literally. Because the updated algorithm allows only one repeat, this page calls any repeat that does not pass a fail, as the Tennessee flowchart does.

After the screen (Tennessee protocol, citing Martin 2020)

• Fail: notify the medical practitioner; evaluate for other causes of low saturation (for example persistent pulmonary hypertension, pneumonia, infection); in the absence of a clear cause, obtain a diagnostic echocardiogram interpreted by an expert in infant echocardiography, reviewed before discharge. SpO₂ <90% at any time needs immediate clinical assessment and no rescreen.
• Pass: does not exclude a cardiac disorder. If cardiac evaluation is otherwise indicated (clinical signs, prenatal diagnosis, dysmorphic features), proceed even after a pass.
• State programs differ in details (for example, the Tennessee protocol adds a foot-first step and rules for screens before 24 hours). Follow your state's protocol.

Input checks

SpO₂ must be a whole number from 50 to 100%. Age 0–720 hours; under 24 hours gives a caution, not a block.

Verification

Checked against the official 2025 AAP screening algorithm (Figure 1, as published by the CDC): this page gives the same pass, repeat or fail result for every combination of hand and foot SpO2 tested (2,601 first screens and 18,207 two-screen sequences), October 2026.

References

• Martin GR, Ewer AK, Gaviglio A, et al. Updated strategies for pulse oximetry screening for critical congenital heart disease. Pediatrics 2020;146(1):e20191650. doi:10.1542/peds.2019-1650 (abstract read via PubMed; full text not retrieved).
• Oster ME, Pinto NM, Pramanik AK, et al. Newborn screening for critical congenital heart disease: a new algorithm and other updated recommendations: clinical report. Pediatrics 2025;155(1):e2024069667. doi:10.1542/peds.2024-069667 (abstract).
• Centers for Disease Control and Prevention. Clinical screening and diagnosis for critical congenital heart defects: cdc.gov/heart-defects/hcp/screening (read October 2026).
• Tennessee Department of Health. Protocol for Critical Congenital Heart Disease (CCHD) Screening, revised 9/21/2021: tn.gov (PDF).