Finnegan NAS Score Calculator — Neonatal Abstinence Syndrome
The Finnegan NAS Scoring Tool assesses the severity of neonatal abstinence syndrome (neonatal opioid withdrawal) using 21 clinical signs across CNS, metabolic/vasomotor/respiratory, and gastrointestinal categories. A score ≥ 8 on two consecutive assessments or ≥ 12 on a single assessment generally triggers pharmacological treatment per most institutional protocols.
Cry pattern
Sleep after feeding
Moro reflex
Tremors when disturbed
Tremors at rest (undisturbed)
Muscle tone
Excoriation
Myoclonic jerks
Convulsions / seizures
Sweating
Fever
Yawning
Mottling
Nasal stuffiness
Sneezing
Nasal flaring
Respiratory rate
Sucking
Feeding
Regurgitation / vomiting
Stools
Total score from 0 (no signs) to 44+ (maximum withdrawal)
- 1
CNS subscore (9 signs)
0 - 2
Metabolic / vasomotor / respiratory subscore (8 signs)
0 - 3
Gastrointestinal subscore (4 signs)
0 - 4
Total Finnegan NAS score
0 + 0 + 0 = 0
How does this calculator work?
The Finnegan NAS score sums 21 weighted signs (CNS, metabolic/vasomotor/respiratory, GI) scored at each nursing assessment. Score < 8: monitor without medication. Score 8–11 on two consecutive assessments or ≥ 12 on one: pharmacotherapy typically indicated. Always follow your institution's protocol — thresholds vary.
Formula
How this is calculated
The Finnegan NAS Scoring Tool was developed by Dr Loretta Finnegan in 1975 and has been revised several times (most institutional versions use the modified or simplified MOTHER NAS Scale). The original tool weights each of 21 signs according to clinical severity: most CNS signs score 2–4 points (tremors undisturbed score up to 4; generalised convulsions score 5), metabolic and vasomotor signs typically score 1–2 points, and gastrointestinal signs score 1–3 points each.
Each assessment is completed every 3–4 hours (or more frequently per unit protocol), always capturing the worst observed sign during the assessment window — not just the current state. Serial scores are used to decide whether non-pharmacological care alone is sufficient or whether morphine, methadone, or another agent should be started. The treatment threshold varies by unit: many use ≥ 8 on two consecutive scores or a single score ≥ 12. Once pharmacotherapy begins, scores guide dose titration and weaning.
Limitations: The Finnegan score is time-consuming (21 items) and has moderate inter-rater reliability. Many centres have adopted shorter validated tools (the Eat, Sleep, Console — ESC — approach or the simplified MOTHER NAS scale). This calculator implements the traditional Finnegan system; always apply your institution's specific protocol and thresholds.
Frequently asked questions
Most institutional protocols initiate pharmacotherapy when the Finnegan score reaches ≥ 8 on two or three consecutive assessments, or ≥ 12 on a single assessment. The exact threshold varies by centre and is often combined with clinical judgment. The ESC (Eat, Sleep, Console) model, an increasingly adopted alternative, focuses on function rather than score alone.
First-line pharmacotherapy in most guidelines is oral morphine solution (opioid replacement). Methadone is used in some centres. Adjunct agents such as clonidine or phenobarbital may be added for severe or refractory cases. Non-pharmacological care — skin-to-skin contact, low-stimulation environment, breastfeeding if the mother is stable on opioid maintenance therapy — is cornerstone management regardless of score.
The traditional protocol recommends every 3–4 hours, always using the worst observation over the full assessment window. Assessment should occur 30–60 minutes after feeding for consistency. More frequent assessment (every 2 hours) is used when scores are elevated or when titrating pharmacotherapy.
Also known as
TG we-Calculate Editorial Team. (2026). Finnegan NAS Score Calculator — Neonatal Abstinence Syndrome [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/finnegan-nas-calculator
TG we-Calculate Editorial Team. "Finnegan NAS Score Calculator — Neonatal Abstinence Syndrome." TG we-Calculate. 2026. https://we-calculate.com/calculator/finnegan-nas-calculator.
TG we-Calculate Editorial Team, "Finnegan NAS Score Calculator — Neonatal Abstinence Syndrome," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/finnegan-nas-calculator
@misc{wecalculate_finnegan_nas_calculator, title = {Finnegan NAS Score Calculator — Neonatal Abstinence Syndrome}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/finnegan-nas-calculator}}, year = {2026}, note = {TG we-Calculate} }
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