Silverman-Anderson Score
What It Is and Its Purpose
The Silverman-Anderson score is a clinical assessment tool that evaluates respiratory distress severity in newborns by scoring five physical signs: upper chest retractions, lower chest retractions, xiphoid retractions, nasal flaring, and expiratory grunting, with each parameter scored 0-2 for a total possible score of 0-10. 1
The score serves as a bedside clinical tool to:
- Quantify the severity of respiratory distress in real-time 1
- Guide escalation of respiratory support (higher scores indicate need for more aggressive intervention) 1
- Monitor response to treatment by tracking score changes over time 1
Specific Components Being Assessed
Each of the five parameters reflects specific pathophysiologic mechanisms:
Upper chest movement - Paradoxical inward movement during inspiration indicates increased work of breathing and poor chest wall stability 1
Lower chest wall indrawing - In infants younger than 2 years, this sign alone has decreased specificity, but when combined with other signs of severe distress or hypoxemia, it becomes highly specific for pulmonary disease and substantially increases mortality risk 1
Xiphoid retraction - Severe indrawing at the xiphoid process, along with tracheal tugging and head nodding, indicates severe respiratory distress requiring immediate escalation of care 1
Nasal flaring - Consistent and repetitive outward movement of the ala nasi during inspiration represents the infant's attempt to reduce inspiratory resistance 1
Expiratory grunting - Repetitive "eh" sounds during early expiration represent the infant's attempt to generate positive end-expiratory pressure and maintain lung volume, making it a key clinical feature of respiratory distress 1
Application in Preterm Infants with Chronic Lung Disease
While the Silverman-Anderson score was originally designed for acute respiratory distress assessment, its application in chronic lung disease of infancy (CLDI) contexts requires understanding important limitations:
For acute exacerbations: The score remains useful for assessing severity during acute respiratory decompensation in infants with established bronchopulmonary dysplasia (BPD) 2
Baseline assessment limitations: Infants with CLDI often have chronic baseline retractions and increased work of breathing, making the score less discriminatory for chronic severity assessment 2
Better alternatives for chronic severity: For established CLDI, other scoring systems provide more comprehensive assessment:
- Pulmonary severity scores that incorporate FiO2, respiratory support type, and medications (ranging 0.21-2.95) better predict subsequent pulmonary morbidity through 3 months corrected age 3
- Respiratory Severity Score (RSS) - the product of mean airway pressure and FiO2 - when ≥2 on the first day of life, is associated with increased mortality and morbidities in infants ≤1250g 4
Critical Clinical Context
Objective measurements must supplement clinical scoring: Pulse oximetry with SpO2 <93% (adjusted for altitude) defines hypoxemia and should always accompany clinical assessment 1
Respiratory rate must be counted over a full minute - brief spot checks are insufficient for accurate severity evaluation 1
Severe tachypnea thresholds: ≥70 breaths/minute in infants 2-11 months or ≥60 breaths/minute in children 12-59 months indicates severe respiratory distress 1
Common Pitfalls to Avoid
Do not rely solely on Silverman-Anderson scoring in established CLDI - it was designed for acute respiratory distress syndrome assessment, not chronic disease severity stratification 2
Do not use brief assessments - periods of acute hypoxia, whether intermittent or prolonged, are common causes of persistent pulmonary hypertension in BPD, requiring continuous or prolonged monitoring rather than spot checks 2
Do not ignore the multisystem nature of CLDI - respiratory assessment alone is insufficient, as CLDI is truly a multisystem disorder requiring comprehensive evaluation 2