Pediatric Asthma Score (PAS)

Calculate the Pediatric Asthma Score (PAS) for children aged 2 and older: five domains (respiratory rate, oxygenation, auscultation, retractions, dyspnea), total 5 to 15. Mild 5 to 7, moderate 8 to 11, severe 12 to 15.

Pediatric Asthma Score (PAS) Calculator

Do not use in children under 2 years of age, in severe distress, or when another diagnosis clearly explains the presentation. For ages 2 years and older with acute asthma exacerbation, select the age group and score each of the five PAS components.

Clinical parameters

Patient age group

Respiratory Rate

Oxygen requirements

Auscultation

Retractions

Dyspnea

Disclaimer: The Pediatric Asthma Score (PAS) is an educational clinical decision-support tool intended for children aged 2 years and older. It does not replace assessment of airway, breathing, and circulation, comprehensive evaluation, or institutional protocols. Do not delay emergent care to complete a score.

Pediatric Asthma Score (PAS): formula, variables, and clinical context

Overview

The Pediatric Asthma Score (PAS) stratifies severity of asthma exacerbation in children aged 2 years and older. It uses five bedside domains (respiratory rate, oxygen requirements, auscultation, retractions, and dyspnea), each scored 1 to 3, for a total of 5 to 15. The PAS is widely used in inpatient asthma pathways and aligns with the same component definitions as the respiratory clinical score described by Liu et al. and the asthma pathway work of Kelly et al.

Scoring components

1. Respiratory Rate

Thresholds are age-adjusted. Select the appropriate age group, then score based on the observed respiratory rate.

Age group	Score 1	Score 2	Score 3
2-3 years	≤34	35-39	≥40
4-5 years	≤30	31-35	≥36
6-12 years	≤26	27-30	≥31
>12 years	≤23	24-27	≥28

2. Oxygen requirements (SpO₂ on room air or need for supplemental O₂)

Score	Finding
1	>95% on room air
2	90-95% on room air
3	<90% on room air, or requiring supplemental O₂

3. Auscultation

Score	Finding
1	Normal breath sounds or end-expiratory wheezing only
2	Expiratory wheezing
3	Inspiratory and expiratory wheezing, or diminished breath sounds

4. Retractions

Score	Finding
1	No retractions or intercostal only
2	Intercostal and substernal retractions
3	Intercostal, substernal, and supraclavicular retractions

5. Dyspnea

Score	Finding
1	Speaks in full sentences (or coos/babbles)
2	Speaks in partial sentences (or short cries)
3	Single words or short phrases (or grunts)

Interpretation

Total score	Severity	Predicted peak flow
5-7	Mild exacerbation	>70%
8-11	Moderate exacerbation	50-70%
12-15	Severe / status asthmaticus	<50%

Component details

Respiratory Rate

Respiratory rate is age-dependent. Younger children normally have higher resting respiratory rates, so thresholds are adjusted by age group. Tachypnea in the context of an asthma exacerbation reflects increased work of breathing and air trapping. Count respirations over a full 60 seconds for accuracy, particularly in young children where breathing may be irregular.

Oxygen requirements

Pulse oximetry provides a non-invasive, continuous measure of oxygenation. In asthma, ventilation-perfusion mismatch leads to hypoxemia. An SpO₂ >95% on room air suggests adequate gas exchange. Values of 90-95% indicate moderate impairment, while <90% (or the need for supplemental oxygen) signals severe compromise. Note that SpO₂ may remain normal even with significant airway obstruction early in an exacerbation, especially in older children.

Auscultation

Wheezing results from turbulent airflow through narrowed airways. End-expiratory wheezing alone indicates mild obstruction. Wheezing throughout expiration indicates moderate obstruction. Biphasic (inspiratory and expiratory) wheezing or diminished breath sounds suggests severe obstruction. Critically, a “silent chest” with minimal air movement can indicate very severe obstruction and impending respiratory failure, which should score 3.

Retractions

Retractions reflect the use of accessory respiratory muscles to generate increased negative intrathoracic pressure. Intercostal retractions alone are mild. Intercostal plus substernal retractions indicate moderate work of breathing. Involvement of substernal and supraclavicular patterns indicates severe respiratory distress. In infants and toddlers, substernal and suprasternal retractions may be more prominent due to increased chest wall compliance.

Dyspnea

The ability to speak in sentences versus short phrases or single words is a practical bedside measure of respiratory distress. Full sentence speech suggests mild dyspnea. Partial sentences indicate moderate distress. Single words, short phrases, or grunting indicates severe dyspnea. In preverbal children, use vocalisation equivalents: cooing/babbling (mild), short cries (moderate), or grunting (severe).

Management by severity

Mild (score 5-7)

Inhaled SABA (e.g., albuterol) every 20 minutes for up to 1 hour
Consider oral corticosteroids if incomplete response
Reassess after each treatment
Discharge with asthma action plan if good response

Moderate (score 8-11)

Frequent SABA (every 20 min or continuous nebulization)
Add ipratropium bromide
Systemic corticosteroids (oral or IV)
Supplemental oxygen to maintain SpO₂ >92%
Serial reassessment; observation period before disposition

Severe / status asthmaticus (score 12-15)

Continuous nebulized SABA
Ipratropium bromide
IV corticosteroids
Consider IV magnesium sulfate
Supplemental oxygen; may require high-flow nasal cannula or NIPPV
ICU admission may be necessary
Prepare for possible intubation if deteriorating

Background

Pathway context: Kelly et al. developed a therapy-driven inpatient asthma pathway in which the PAS (or peak flow) measured response to treatment alongside NHLBI-style guidance.
Population: Children aged 2 years and older with asthma exacerbation. Do not use in infants under 2, patients in severe distress where ABC takes priority, or when an alternative diagnosis is clear.
Score structure: Five domains, each 1 to 3 points, sum to 5 to 15. Mild 5 to 7, moderate 8 to 11, severe 12 to 15.
Related literature: The same component definitions underlie the respiratory clinical score inter-rater work (Liu et al., Pediatr Pulmonol 2004).

Limitations

Age restriction: The score is validated for children aged 2 years and older. It should not be used in infants under 2, where bronchiolitis or other diagnoses should be considered.
Subjectivity: Some components (auscultation, retractions, dyspnea) involve subjective assessment. Inter-rater reliability is generally good but not perfect.
Single time-point: The score captures a snapshot in time. Serial scoring (before and after bronchodilator therapy) is recommended to assess treatment response.
Not a standalone tool: The score should be used in conjunction with clinical judgment, patient history, and other clinical parameters. It does not account for factors such as previous ICU admissions, chronic medication use, or comorbidities.
Peak flow correlation: Predicted peak flow ranges are approximations and may not precisely match actual spirometry results in all patients.

Key references

Liu LL, Gallaher MM, Davis RL, Rutter CM, Lewis TC, Marcuse EK. Use of a respiratory clinical score among different providers. Pediatr Pulmonol. 2004;37(3):243-248.
Kelly CS, Andersen CL, Pestian JP, et al. Improved outcomes for hospitalized asthmatic children using a clinical pathway. Ann Allergy Asthma Immunol. 2000;84(5):509-516.
National Asthma Education and Prevention Program. Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma. NIH Publication No. 07-4051. 2007.
Ducharme FM, Chalut D, Plotnick L, et al. The Pediatric Respiratory Assessment Measure: a valid clinical score for assessing acute asthma severity from toddlers to teenagers. J Pediatr. 2008;152(4):476-480.
Global Initiative for Asthma (GINA). Global Strategy for Asthma Management and Prevention. 2023. Available at: ginasthma.org.

Practice caveats

The score was developed and validated primarily in pediatric populations. Use in adults is extrapolated and should be interpreted with caution.
A “silent chest” with diminished breath sounds may paradoxically yield a high auscultation score (3) but could indicate impending respiratory failure rather than simple bronchospasm.
Serial scoring is more clinically useful than a single assessment. Re-score after each bronchodilator treatment to assess response and guide escalation or de-escalation of therapy.
The score does not replace arterial blood gas analysis, chest imaging, or other diagnostic modalities when clinically indicated.

What the Pediatric Asthma Score (PAS) measures

The Pediatric Asthma Score (PAS) is a bedside tool used to describe how severe an acute asthma exacerbation appears in a child. It does not replace spirometry or peak flow when those are available, but it bundles five observable domains into one number so nurses, respiratory therapists, and physicians can communicate severity consistently and trigger pathway steps in many hospitals. Each domain is scored from 1 (least abnormal) to 3 (most abnormal). All five scores are added, so the total PAS ranges from 5 to 15. The same item definitions underlie the respiratory clinical score used in pediatric asthma literature and common inpatient asthma pathways.

Intended population and setting

The PAS is intended for children aged 2 years and older. Below age two, respiratory rates, cooperation with auscultation, and language-based dyspnea descriptors are less reliable, and other entities (bronchiolitis, viral wheeze) dominate the differential. Typical use cases include the emergency department, urgent care, inpatient wards, and observation units where teams reassess patients after bronchodilator therapy. The score works best when measured serially, because response to treatment is often more informative than a single snapshot.

The five scoring domains

1. Respiratory rate (age-adjusted)

Tachypnea is a core marker of increased work of breathing, but normal respiratory rate falls with age. The PAS uses age bands so that a given rate is interpreted relative to expected physiology for 2 to 3 years, 4 to 5 years, 6 to 12 years, and over 12 years. For each band, lower rates receive a score of 1, intermediate rates a score of 2, and higher rates a score of 3. Count respiratory rate when the child is as calm as possible; crying and fever can elevate the rate independently of bronchospasm.

Age group	Score 1 (mild elevation)	Score 2	Score 3 (marked elevation)
2 to 3 years	≤34 breaths/min	35 to 39 breaths/min	≥40 breaths/min
4 to 5 years	≤30 breaths/min	31 to 35 breaths/min	≥36 breaths/min
6 to 12 years	≤26 breaths/min	27 to 30 breaths/min	≥31 breaths/min
>12 years	≤23 breaths/min	24 to 27 breaths/min	≥28 breaths/min

2. Oxygen saturation and supplemental oxygen

This domain reflects how well oxygen is reaching peripheral tissues during the exacerbation. Score 1 corresponds to SpO₂ over 95% on room air. Score 2 corresponds to 90 to 95% on room air. Score 3 corresponds to SpO₂ under 90% on room air or any need for supplemental oxygen to maintain acceptable saturation. Use a reliable pulse oximeter probe, account for motion artifact in young children, and remember that hypotension, anemia, or poor perfusion can distort readings even when ventilation is compromised.

3. Auscultation

Lung sounds grade airway narrowing and air movement. Score 1 reflects normal breath sounds or end-expiratory wheeze only. Score 2 reflects expiratory wheezing. Score 3 reflects inspiratory and expiratory wheezing or diminished breath sounds. Diminished sounds may indicate severe obstruction with poor air entry or fatigue and should prompt heightened vigilance even when wheeze seems less prominent.

4. Retractions

Accessory muscle use signals increased work of breathing. Score 1 is none or intercostal retractions only. Score 2 adds substernal retractions. Score 3 adds supraclavicular retractions in addition to intercostal and substernal pulling. Supraclavicular indrawing often marks substantial negative intrathoracic pressure swings and is a visual cue that the child is working hard to ventilate.

5. Dyspnea (speech and vocal pattern)

This item adapts to developmental stage. Score 1 means the child speaks in full sentences, or in toddlers cooing or babbling in a comfortable pattern. Score 2 means partial sentences or short cries. Score 3 means single words or short phrases, or grunting in infants. Progressive inability to speak in full sentences reflects tiring respiratory mechanics and rising obstruction.

Total score and severity bands

Sum the five domain scores (minimum 5, maximum 15). In common teaching aligned with this calculator, totals map to exacerbation severity and to predicted peak expiratory flow zones when personal best is known:

Total 5 to 7: Mild exacerbation; predicted peak flow often described as over 70% of personal best. Typical initial steps emphasize inhaled short-acting beta-agonist (SABA) therapy with structured reassessment. Many patients can be managed as outpatients if they improve and follow-up is arranged.
Total 8 to 11: Moderate exacerbation; predicted peak flow often described as 50 to 70% of personal best. Management usually intensifies (repeat SABA, anticholinergic therapy per protocol, systemic corticosteroids) with close observation and serial scores until disposition is clear.
Total 12 to 15: Severe exacerbation or impending status asthmaticus; predicted peak flow often described as under 50% of personal best. Care is aggressive and escalates toward continuous bronchodilator therapy, adjunct medications such as magnesium sulfate when indicated, and higher-acuity monitoring with readiness for airway support if fatigue or hypercapnia develops.

Exact medication choices, doses, and location of care (general floor versus intensive care) must follow local guidelines and clinician judgment.

Why the PAS is useful in pathways

Asthma pathways rely on objective, repeatable criteria so that triage, bronchodilator frequency, steroid timing, and disposition decisions feel consistent across shifts. Because each PAS component maps to visible physiology, the score reduces ambiguity when families describe subjective “trouble breathing.” Serial PAS values create a trend line that complements peak flow or spirometry when those modalities are feasible.

Limitations and pitfalls

Acronym collision: “PAS” appears in other specialties (for example, appendicitis scores). Always specify pediatric asthma context in documentation.
Overlap with other illnesses: Wheezing and tachypnea are not exclusive to asthma; foreign body, pneumonia, and heart failure can distort individual domains.
Treatment effects: After nebulizers, wheeze may paradoxically sound louder while overall work of breathing improves. Interpret the score alongside mental status and perfusion.
Spirometry and peak flow: The PAS correlates with peak-flow zones in teaching summaries but does not replace lung function measurement when available and reliable.
Silent chest: Very severe obstruction may reduce audible wheeze; mental status changes, fatigue, or rising carbon dioxide levels demand escalation even if the score does not capture every danger signal.

Educational use

This calculator supports learning and standardized severity labeling. It is not a substitute for individualized medical assessment, institutional protocols, or direct patient evaluation.