CoSense® BiliCalc™ v21 — 2022 AAP ETCOc-Driven Neonatal Bilirubin Calculator

Measurement Guide

ETCOc Assessment Framework

● < 1.7 ppm — Normal production · Standard phototherapy thresholds
● 1.7–1.9 ppm — Elevated production · Compressed monitoring · Standard thresholds maintained
● 2.0–2.3 ppm — Elevated production · Both thresholds presented for clinical assessment
● ≥ 2.4 ppm — Significant hemolysis · RF-adjusted phototherapy thresholds applied automatically

Evidence Base for Tier Boundaries

1.7 ppm: above US well-baby population mean (Schutzman ~1.7 ppm; institutional QI ~1.6 ppm)
2.0–2.3 ppm: Yang OR 2.31 for 1.5–2.5 ppm range — clinician judgment zone
2.4 ppm: convergent evidence — institutional QI 95th percentile · Yang OR 4.56 at ≥2.5 ppm · Schutzman significant hemolysis 2.5 ppm

ETCOc Measurement Timing

Standard: 12–24 HOL
High-risk (DAT+, incompatibility, jaundice <24h): 6–12 HOL + repeat at 24h
G6PD/SCD risk: Serial at 24, 48, 72h — enter below

TcB / TSB Measurement Timing (AAP 2022)

Universal TcB screen: Before discharge or at 24–48 HOL
If TcB within 3 mg/dL of phototherapy threshold: Confirm with TSB (KAS 6)
If TSB rising: Repeat every 4–24h based on proximity to threshold and rate of rise
During phototherapy: TSB within 4–6h of initiation, then every 6–12h
Post-phototherapy: Rebound TSB within 12–24h of discontinuation

Patient Parameters

GA — weeks Required

GA — days (0–6) Required

Birth Weight (grams) optional

SGA flag if <10th %ile for GA. Observational only — does not change AAP thresholds directly.

AAP 2022 threshold tables are stratified by completed weeks. Each TcB/TSB entry below includes its own age-at-draw timestamp and is compared at that specific hour’s threshold.

Clinical Risk Flags — optional

Neurotoxicity risk factor present (non-hemolytic)

Albumin < 3.0 g/dL · Sepsis · Clinical instability in prior 24h

RF-adjusted phototherapy thresholds apply regardless of ETCOc tier (AAP 2022 Table 2).

Known or suspected G6PD deficiency

Triggers serial ETCOc monitoring. Standard thresholds apply while ETCOc confirms normal production. Tier framework activates if hemolysis onset is detected.

Clinical context (advisories only — does not change thresholds)

Maternal smoking history (CO confound for ETCOc interpretation) Cephalohematoma or significant bruising Breastfeeding concerns or weight loss > 8% Delayed stooling or elimination concerns

ETCOc Measurement — CoSense®

Primary ETCOc Required

ETCOc Value (ppm)

Age at Measurement (hours of life)

For G6PD/SCD risk or when repeat is clinically indicated

🔄 Serial ETCOc — Session Trend

Compared to primary measurement to assess hemolytic trend. Not stored — record all ETCOc values in the patient's clinical notes.

Second ETCOc Value (ppm)

Age at Second Measurement (hours of life)

ℹ️ For multi-session longitudinal tracking (G6PD, SCD), record all values in the EHR. A future HIPAA-compliant platform is planned for cross-session serial monitoring.

TcB / TSB Readings — each with age at draw

Bilirubin entries Each reading is evaluated at its own drawn-age threshold

Enter multiple readings to track trajectory. Earliest reading must have the lowest age. TSB automatically takes precedence over TcB for the same draw.