What are the Silverman-Anderson and Downes scores?
They are bedside scores that put a number on a newborn's work of breathing. Each has five items, each item is scored 0, 1 or 2, and the total runs from 0 to 10. Unlike the Apgar score, a higher score is worse: 0 means comfortable breathing and 10 means severe distress.
The Silverman-Anderson score comes from a 1956 Pediatrics paper by Silverman and Andersen — a controlled trial of water mist in premature infants — and is a graded description of the signs of respiratory distress in preterm babies. The Downes score was published in 1970 by Downes, Vidyasagar, Boggs and Morrow in Clinical Pediatrics as a new clinical scoring system for respiratory distress syndrome, with acid-base and blood-gas correlations.
What are the five items of the Silverman-Anderson score?
| Item | 0 | 1 | 2 |
|---|---|---|---|
| Upper chest movement | Synchronous with abdomen | Lag (delayed) on inspiration | See-saw (paradoxical) movement |
| Lower chest (intercostal) retraction | None | Barely (just) visible | Easily visible / marked |
| Xiphoid retraction | None | Barely (just) visible | Easily visible / marked |
| Nasal flaring (nares dilatation) | None | Barely visible | Easily visible |
| Expiratory grunt | None | Heard only with a stethoscope | Heard with the naked ear |
Four items are inspiratory signs and one — the grunt — is expiratory. Apart from listening for the grunt, the whole score is done by watching the baby, which is why it is quick: in one comparison in term neonates it took about 90 seconds against about 150 seconds for the Downes score.
What are the five items of the Downes score?
| Item | 0 | 1 | 2 |
|---|---|---|---|
| Respiratory rate (/min) | < 60 | 60–80 | > 80 |
| Retractions | None | Mild | Severe |
| Cyanosis | None | Relieved by oxygen | Persists on oxygen |
| Air entry | Good bilateral air entry | Mildly decreased | No air entry |
| Grunting | None | Audible with stethoscope | Audible with the ear |
The respiratory-rate cut-off of 60 per minute matches the usual definition of neonatal tachypnoea (more than 60 breaths per minute). Because Downes includes cyanosis and air entry, it needs a little more time and a stethoscope for the whole examination, but it carries information about oxygenation that Silverman-Anderson does not.
How are the scores interpreted?
Cut-offs vary between papers and units, so learn the commonly quoted bands and the principle that a rising score means a baby who is tiring.
| Severity | Silverman-Anderson | Downes |
|---|---|---|
| No distress | 0 | 0 |
| Mild | 1–3 | 1–4 (other texts: < 4 = no or mild distress) |
| Moderate | 4–6 | 5–7 (other texts: 4–7 = respiratory distress) |
| Severe | > 6 | > 7 = severe distress / impending respiratory failure |
When is each score used — preterm or term?
Silverman and Andersen built their index in premature infants, and it remains the score most associated with preterm babies. A common convention — used, for example, in a recent Indian NICU study — is Downes for term neonates and Silverman-Anderson for preterm neonates.
- Preterm baby with surfactant-deficiency RDS: chest-wall signs such as see-saw breathing and retractions dominate the picture — exactly what Silverman-Anderson grades.
- Term baby (TTN, meconium aspiration, pneumonia): Downes adds rate, cyanosis and air entry. In one study of 428 term neonates, Downes predicted respiratory failure slightly better (AUC 0.918 vs 0.876; best cut-offs 6 and 4.5).
- Both are repeated serially — on admission, during CPAP and while weaning. One study defined CPAP success as a Downes score of 3 or less with saturation above 90% in room air.
How do you score a baby at the bedside?
- Settle the baby and expose the chest and abdomen. Crying changes every item, so score a quiet baby, and note any respiratory support (oxygen, CPAP) the baby is already on.
- Watch the chest against the abdomen. If both rise together the upper chest scores 0; if the chest lags behind on inspiration it scores 1; if the chest sinks while the abdomen rises (see-saw) it scores 2.
- Look for retractions between the ribs (lower chest) and below the sternum (xiphoid) — barely visible scores 1, easily visible scores 2.
- Look at the nostrils for flaring.
- Listen for a grunt — first without, then with a stethoscope. Audible with the naked ear = 2; only with a stethoscope = 1.
- For Downes, also count the respiratory rate, look for cyanosis (and whether oxygen relieves it) and auscultate both sides for air entry.
- Record the total and repeat it. One CPAP protocol re-scores every 2 to 4 hours after starting CPAP; a rising score means escalation, a falling score supports weaning.
How do the scores guide CPAP and escalation?
Both scores are most useful where blood gases and X-rays are not always available. A study from a regional referral hospital in Tanzania describes the Silverman-Anderson score being recommended for prioritising which neonates get the limited CPAP machines, with the score repeated every 2–4 hours once CPAP is started.
| Finding | Study |
|---|---|
| Silverman-Anderson ≥ 5 within 1 hour of birth strongly associated with needing more respiratory support over the next 24 hours | Hedstrom 2018, 140 newborns |
| Silverman-Anderson of 6 at 6 hours associated with CPAP failure | Indian case series cited by Hedstrom |
| Very early studies: a score of ≥ 2 in babies under 2 kg associated with mortality and RDS at autopsy | Cited by Hedstrom |
| Initial Downes score a significant predictor of nasal CPAP failure in preterm infants | Permatahati 2021 |
| Downes > 7 (or FiO2 ≥ 50%) after 15–20 minutes of CPAP may predict CPAP failure | Koti et al., cited by Permatahati |
Why do grunting, flaring and retractions occur?
| Sign | Mechanism |
|---|---|
| Expiratory grunt | Sudden closure of the glottis during expiration raises airway pressure and lung volume, preventing alveolar collapse — a self-generated PEEP |
| Nasal flaring | Contraction of the alae nasi widens the upper airway, reducing resistance and work of breathing |
| Retractions | Poor lung compliance or high airway resistance; negative intrapleural pressure from diaphragm and accessory-muscle contraction pulls the chest wall in |
| See-saw breathing | Paradoxical chest and abdominal movement — the chest sinks in while the abdomen rises |
| Tachypnoea | Rate > 60/min — the standard definition in a newborn |
What are the common causes of respiratory distress in a newborn?
Most causes are pulmonary: transient tachypnoea of the newborn (TTN), respiratory distress syndrome (RDS), meconium aspiration syndrome (MAS), pneumonia and sepsis, pneumothorax, persistent pulmonary hypertension and delayed transition. TTN is the most common.
| Condition | Typical baby | Mechanism | Key clues |
|---|---|---|---|
| TTN | Term or near-term; caesarean before labour | Delayed clearance of fetal lung fluid | Self-limiting, usually settles within 72 hours; X-ray: prominent vascular markings, fluid in the fissures, hyperinflation |
| RDS (hyaline membrane disease) | Preterm; also infant of diabetic mother, male, multiple gestation, caesarean without labour | Surfactant deficiency → high surface tension → alveolar collapse at end-expiration | Starts soon after birth and worsens over the first hours; grunting, retractions, cyanosis |
| MAS | Term or post-term, meconium-stained liquor | Airway plugging; bile salts inactivate surfactant → chemical pneumonitis | Meconium-stained liquor in 10–15% of births, but MAS in only about 1% |
| Pneumonia / sepsis | Any gestation | Infection | Always consider in a baby with distress; listed among the commonest pulmonary causes |
What are the common exam traps with these scores?
- Direction: Apgar — higher is better. Silverman-Anderson and Downes — higher is worse.
- Grunt scoring is identical in both: 1 = heard only with a stethoscope, 2 = heard with the naked ear.
- See-saw respiration is the score-2 description of upper chest movement in Silverman-Anderson — not a Downes item.
- Cyanosis relieved by oxygen scores 1 in Downes; cyanosis persisting on oxygen scores 2.
- Respiratory rate 60–80 scores 1; above 80 scores 2 in Downes.
- Maximum for each score is 10, not 12 — five items × 2.