Pediatric Asthma Severity Score (PASS)

Calculate the Pediatric Asthma Severity Score (PASS) for acute asthma exacerbation in children about 1 to 18 years: wheezing, work of breathing, and prolongation of expiration (total 0 to 6).

Pediatric Asthma Severity Score (PASS)

For children about 1 to 18 years with acute asthma exacerbation. Grade each physical examination domain (0 to 2 points). Total score ranges from 0 to 6; higher scores reflect more pronounced findings. Severity bands below are a teaching framework; follow your institution's pathway.

Wheezing

Auscultatory wheeze and overall air movement.

Work of breathing

Accessory muscle use and retractions.

Prolongation of expiration

Ratio of expiration time to inspiration time.

Disclaimer: PASS is an adjunct to clinical assessment. It does not replace pulse oximetry, observation after bronchodilators, or pathway-specific criteria for disposition. Scores work best when measured initially and after treatment to show trend. Always apply institutional asthma protocols and clinical judgment.

PASS: domains, scoring, and evidence

Overview

The Pediatric Asthma Severity Score (PASS) summarizes acute asthma severity on physical examination using three domains, each scored 0 to 2 points. The total ranges from 0 to 6, with higher values reflecting more pronounced findings. It was developed and validated in the pediatric emergency setting and correlates with objective measures such as peak flow and oxygen saturation.

Domains and points

Domain	Finding	Points
Wheezing	None or mild	0
	Moderate	1
	Severe wheezing, or absent due to poor air movement	2
Work of breathing	Normal or mildly diminished (accessory muscles, retractions)	0
	Moderate	1
	Severe	2
Prolongation of expiration	Normal or mildly prolonged (expiration relative to inspiration)	0
	Moderately prolonged	1
	Severely prolonged	2
Total possible		0 to 6

Interpretation

The original publication emphasized correlation with clinical severity and responsiveness to treatment rather than fixed disposition cutoffs. Many educators group totals roughly as mild (0 to 2), moderate (3 to 4), and severe (5 to 6) for bedside teaching. Local pathways may define treatment and disposition differently.

Key reference

Gorelick MH, Stevens MW, Schultz TR, Scribano PV. Performance of a novel clinical score, the Pediatric Asthma Severity Score (PASS), in the evaluation of acute asthma. Acad Emerg Med. 2004 Jan;11(1):10-8. doi:10.1197/j.aem.2003.07.015

Practice notes

PASS should not be used in isolation. Integrate vitals, pulse oximetry, response to bronchodilators, and history.
Absence of wheeze with poor air movement scores in the highest wheezing category and can indicate severe obstruction.
Repeat scoring during the visit helps document improvement or deterioration alongside clinician reassessment.

What the Pediatric Asthma Severity Score (PASS) is

The Pediatric Asthma Severity Score (PASS) is a compact physical examination tool that summarizes how severe an acute asthma exacerbation looks at the bedside. It uses three domains, each graded from 0 (least concerning) to 2 (most concerning). The scores are added so the total PASS ranges from 0 to 6, with higher totals reflecting more pronounced examination findings. The score was developed for use in pediatric emergency and acute care settings and is often paired with vitals, pulse oximetry, and response to bronchodilators rather than used alone.

Population and purpose

PASS is intended for pediatric patients, commonly described as roughly 1 to 18 years of age, presenting with wheezing episodes attributed to asthma or asthma-like obstruction where standardized examination grading helps communication across nurses, therapists, and physicians. It does not distinguish viral wheeze from asthma in biology; it describes severity of the current exacerbation as expressed through auscultation and visible work of breathing. It is particularly useful when teams want a repeatable severity label before and after nebulizer treatments.

The three domains

Each domain captures a different facet of airflow limitation and respiratory effort. Together they approximate what clinicians integrate intuitively: airway noise, accessory muscle use and retractions, and the timing imbalance between inspiration and expiration.

1. Wheezing

This domain reflects auscultatory wheeze and overall sense of air movement. Quiet lungs from excellent airflow score lower than loud diffuse wheeze. Importantly, absent wheeze because of poor air movement belongs in the highest category, not the lowest. In severe obstruction the chest may not transmit classic wheeze despite life-threatening distress.

Finding	Points
None or mild	0
Moderate	1
Severe wheezing, or absent due to poor air movement	2

2. Work of breathing

This domain captures accessory muscle recruitment and retractions. Mild or normal effort scores 0, clear moderate distress scores 1, and marked accessory use scores 2. This aligns with the visual impression of how hard the child is working to move air, independent of whether wheeze is audible.

Finding	Points
Normal or mildly diminished	0
Moderate	1
Severe	2

3. Prolongation of expiration

This domain reflects the ratio of expiratory time to inspiratory time. Air trapping and bronchospasm prolong expiration relative to inspiration. Mild prolongation scores lower than obvious sustained expiratory phase or near-complete dominance of the expiratory effort.

Finding	Points
Normal or mildly prolonged	0
Moderately prolonged	1
Severely prolonged	2

Computing and interpreting the total

Add the three domain points. The minimum total is 0 and the maximum is 6. The original work emphasized correlation with clinical severity and responsiveness to treatment rather than rigid disposition rules from the total alone. Many teaching summaries group totals for bedside orientation as follows:

0 to 2: findings consistent with a milder exacerbation pattern on examination. Continue bronchodilator therapy and reassess on the schedule your pathway defines. Serial PASS after therapy usually matters more than a single pretreatment value.
3 to 4: an intermediate pattern often labeled moderate in educational materials. This range typically prompts closer observation, more frequent treatments, and earlier consideration of systemic corticosteroids per protocol.
5 to 6: a high-severity examination pattern. Management should follow severe exacerbation pathways for your setting, with heightened monitoring and readiness to escalate care. Remember that the wheezing domain’s top tier includes poor air movement without audible wheeze, a scenario that still yields a high domain score.

Your institution may define medication timing, observation duration, and admission thresholds differently. Always integrate mental status, oxygenation, perfusion, and treatment response, not only the numeric total.

How PASS differs from other asthma scores

Several pediatric asthma scores exist. The PASS is deliberately short and based on examination alone (three domains, seven-point spread after summation). Other instruments add respiratory rate, oxygen saturation, or dyspnea descriptors and use different scales (for example 5 to 15). When comparing patients or research cohorts, verify which score was used because acronyms overlap (PASS versus PAS Pediatric Asthma Score, and so on).

Practical tips at the bedside

Serial scoring: Recompute PASS after initial SABA doses to document objective improvement or failure to respond.
Silent severe asthma: Do not reassure based on “quiet lungs” until you confirm adequate air entry; poor movement plus minimal wheeze can still produce a top wheezing score.
Observer training: Moderate versus severe labels are inherently subjective. Brief calibration among staff improves consistency.
Context: Anxiety, crying, and fever can alter inspection and auscultation; pause assessment when feasible.

Limitations

PASS does not incorporate SpO₂, respiratory rate, or blood gas results; critical illness can exist with examination lag.
It does not replace peak expiratory flow or spirometry when the patient can perform those maneuvers reliably.
Infants under about one year may be difficult to score consistently for expiration timing and wheeze characterization.
Non-asthma mimics (foreign body, pneumonia, heart failure) can produce abnormal domain scores; the total reflects distress pattern, not definitive etiology.

Educational use

This material supports learning and standardized documentation of examination severity. It is not individualized medical advice and does not replace protocols or direct patient assessment.