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Section 6 — Respiratory Management Verify against local policy v1.0 · July 2026 Baylor Ed. 33 cross-checked Sept 2026

Chapter 6.1 — Respiratory Distress Syndrome & Surfactant Therapy

Built on West Midlands Neonatal Guidelines 2025–28 · European Consensus Guidelines on RDS 2022 · AAP · Baylor Guidelines for Acute Care of the Neonate

Educational guideline — verify locally. Contains respiratory-support and medication dosing that must be verified against your Neonatal Formulary, product label, and local unit policy before use. Does not replace attending neonatologist judgment.
BEDSIDE ACTION BOX — Preterm Infant with Respiratory Distress

1. Overview & Definition

Overview

Respiratory distress syndrome (RDS) is the leading cause of respiratory failure in preterm infants and results from a developmental deficiency of pulmonary surfactant. Without enough surfactant, alveolar surface tension is high, the lungs are stiff and prone to collapse at end-expiration, and gas exchange is impaired. Modern management has shifted away from routine intubation and prophylactic surfactant toward a gentler, lung-protective strategy: support most preterm infants with non-invasive respiratory support (CPAP) from birth and reserve surfactant for those who show early signs of significant surfactant deficiency, delivering it by the least invasive route possible.

Why This Topic Matters

The choices made in the first hours — antenatal steroid coverage, early CPAP versus intubation, the timing and route of surfactant, and how oxygen is titrated — strongly influence survival, air leak, and the risk of bronchopulmonary dysplasia (BPD). Two common errors cause harm: intubating a stable preterm infant who could have been managed on CPAP, and, conversely, delaying surfactant in an infant whose oxygen requirement is climbing. A structured, threshold-driven approach avoids both.

Definition

RDS (surfactant-deficient lung disease, historically "hyaline membrane disease") is a clinical and radiographic syndrome of the preterm infant characterised by early-onset tachypnoea, grunting, nasal flaring, retractions, and a rising oxygen requirement, with a chest radiograph classically showing low lung volumes, a diffuse ground-glass (reticulogranular) pattern, and air bronchograms.

2. Who This Guideline Applies To

Scope
  • Preterm infants (greatest risk <30 weeks; risk decreases with advancing gestation) with early respiratory distress attributable to surfactant deficiency.
  • Infants at high risk of RDS at birth: extreme prematurity, absent or incomplete antenatal corticosteroids, infant of a diabetic mother, elective caesarean without labour, second twin, and male sex.
  • Selected term/late-preterm infants with secondary surfactant deficiency or inactivation (meconium aspiration syndrome, pneumonia/sepsis) — surfactant here is a consultant-led decision, covered under special situations.
  • Not covered here: transient tachypnoea of the newborn, established BPD (Chapter 6.2), and persistent pulmonary hypertension (Chapter 6.3) — although these overlap and are cross-referenced.

3. Key Definitions

Core Terminology

Shared vocabulary for surfactant-deficiency disease and the non-invasive support strategies used to treat it.

TermDefinitionPractical note
RDSSurfactant-deficient lung disease of prematurity with characteristic clinical and ground-glass radiographic features.A clinical diagnosis; the chest film supports but is not required to start treatment.
SurfactantPhospholipid-protein complex (mainly DPPC) produced by type II pneumocytes that lowers alveolar surface tension and prevents end-expiratory collapse.Natural (animal-derived) surfactants are preferred over synthetic.
CPAPContinuous positive airway pressure — non-invasive distending pressure that keeps alveoli open in a spontaneously breathing infant.First-line support for the breathing preterm infant; start 5–6 cmH₂O, up to 8.
LISA / MISTLess-invasive / minimally-invasive surfactant administration — surfactant given through a thin catheter passed between the vocal cords while the infant breathes on CPAP.Preferred route when feasible; avoids mechanical ventilation.
InSurEINtubate–SURfactant–Extubate — brief intubation to give surfactant, then prompt extubation back to CPAP.Use when LISA cannot be performed.
Prophylactic vs rescueProphylactic = within minutes of birth before established RDS; rescue = after RDS is clinically evident.Routine prophylaxis is not recommended in the CPAP era; give early rescue surfactant.
BPDBronchopulmonary dysplasia — chronic lung disease defined by need for respiratory support/oxygen at 36 weeks' postmenstrual age.The main long-term outcome that lung-protective RDS care aims to reduce (see 6.2).

4. Initial Assessment

Recognise & Quantify Distress
  • Signs: tachypnoea (>60/min), expiratory grunting, nasal flaring, intercostal/subcostal and sternal retractions, and rising FiO₂ to maintain saturations. Onset is usually within minutes to the first few hours of life and typically worsens over 24–48 hours before improving.
  • Severity markers: the FiO₂ and CPAP pressure required, degree of work of breathing, apnoea, and blood-gas trend (a respiratory acidosis with hypoxaemia).
  • Immediately exclude mimics/co-existing problems: pneumothorax (sudden deterioration, asymmetry — transilluminate), early-onset sepsis/pneumonia (which can look identical), congenital heart disease, and airway/tube problems if already intubated.
  • Gather context: gestation, antenatal steroid completeness, mode of delivery, maternal risk factors, and cord-gas/resuscitation history.
First-Line Investigations
  • Continuous preductal SpO₂ and, when unstable, arterial/capillary blood gas (expect hypoxaemia with hypercapnia and mixed acidosis).
  • Chest radiograph when the picture is atypical, distress is significant, or after intubation — classic RDS shows low volumes, diffuse ground-glass opacification, and air bronchograms.
  • Full blood count and blood culture; start empirical antibiotics if sepsis cannot be excluded, because pneumonia is indistinguishable from RDS at onset.
  • Blood glucose and, when relevant, echocardiography to exclude congenital heart disease or a haemodynamically significant duct.

5. Diagnostic Approach

RDS vs Its Common Mimics

RDS is a clinical diagnosis; this table separates it from the conditions that most often masquerade as it in the first hours of life.

ConditionClues that favour itTypical chest filmAction
RDSPreterm, distress from birth worsening over 24–48 h, rising FiO₂.Low volumes, diffuse ground-glass, air bronchograms.CPAP; surfactant when thresholds met.
Pneumonia / early-onset sepsisRisk factors (prolonged rupture, maternal fever, GBS), can occur at any gestation, may be indistinguishable from RDS.Can mimic RDS or show focal/asymmetric change.Cover with antibiotics; surfactant may still help.
Transient tachypnoea (TTN)Term/late-preterm, caesarean without labour, distress improving over hours.Wet lungs, fluid in fissures, hyperinflation.Supportive; usually self-limiting.
Pneumothorax / air leakSudden deterioration, asymmetric chest, on positive pressure.Lucent hemithorax, mediastinal shift.Transilluminate; drain if tension.
Congenital heart disease / PPHNCyanosis out of proportion to lung disease, pre-/post-ductal SpO₂ gap, murmur.Often clear or variable lung fields.Echocardiography; consider prostaglandin/iNO (see 3.3, 6.3).
Diagnostic Principle

Do not wait for a radiograph to begin lung-protective support. Start CPAP on clinical grounds, treat presumed infection until excluded, and let the trajectory of the oxygen requirement — not a single film — drive the decision to give surfactant.

6. Management Algorithm

1
Delivery room — anticipate
Ensure antenatal steroids are documented, keep warm, support transition. For the spontaneously breathing preterm infant, start CPAP (5–6 cmH₂O) rather than routine intubation. Titrate oxygen to SpO₂ 90–95% with a blender.
2
Needs intubation to be stabilised, or no antenatal steroids & very preterm?
If already intubated for respiratory failure during stabilisation, give surfactant via the ETT once tube position is confirmed. Otherwise continue on CPAP and reassess.
3
On CPAP — is RDS worsening?
Surfactant threshold: FiO₂ ≥0.30 — raise CPAP by 1 every 30 min (20 min if ≥0.50) to 8; give surfactant if still ≥0.30 30 min later. Also load/continue caffeine and re-screen for sepsis and pneumothorax.
4
Give surfactant by the least invasive route
Spontaneously breathing on CPAP, ≤33 weeks, <48 h → LISA (thin catheter). If LISA not feasible → InSurE or ETT surfactant with early extubation. Use poractant alfa 200 mg/kg (2.5 mL/kg).
5
Reassess response
Blood gas within ~30 min. Anticipate rapidly improving compliance — wean FiO₂ promptly to avoid hyperoxia. Do not routinely suction the ETT for several hours after instillation.
6
Ongoing RDS despite first dose?
If the oxygen need stays at 30–40% and other causes are excluded, give 1.25 mL/kg (100 mg/kg) at 12 h, up to two further doses.
7
⚠ Do-not-miss / escalate
Sudden deterioration → exclude pneumothorax (transilluminate), blocked/displaced tube (DOPE), and PPHN. Rising FiO₂ despite surfactant, worsening acidosis, or an oxygenation index climbing toward 15–20 → escalate to consultant and consider transfer to NICU/HFOV/iNO.

7. Step-by-Step Management

Non-Invasive Support First
  • Start CPAP from birth for spontaneously breathing preterm infants with, or at high risk of, RDS; start at 5–6 cmH₂O and raise by 1 up to 8 as the oxygen need rises (section 8).
  • Early CPAP with selective surfactant is preferred to routine intubation and prophylactic surfactant, and reduces the combined risk of death or BPD.
  • Optimise the interface and seal; add caffeine early to support respiratory drive and improve the chance of staying off the ventilator.
Oxygen Targeting
  • Use an air/oxygen blender and preductal pulse oximetry; target SpO₂ 90–95% in preterm infants on supplemental oxygen.
  • Avoid saturations persistently >95% on oxygen (hyperoxia risk) and avoid repeated deep desaturations.
  • Reduce FiO₂ promptly after surfactant, when compliance improves quickly.
Timely Surfactant
  • Give early rescue surfactant when FiO₂ stays ≥0.30 despite CPAP optimised to 8 — ideally within the first 2 hours of established RDS.
  • Choose the least-invasive route the infant can tolerate (LISA > InSurE > ETT with early extubation).
  • If the infant needed intubation for stabilisation, or is very preterm without antenatal steroids, give surfactant via the ETT in the delivery room once position is confirmed.
LISA Procedure — Key Steps
  • Pre-load or continue caffeine (spontaneous breathing is essential) and secure venous access; assemble a team (at least one nurse and one doctor).
  • Keep the infant on CPAP throughout; place an N/OG tube to help identify the oesophagus; minimise heat loss.
  • Premedicate with atropine 0.02 mg/kg and fentanyl 0.5–1 mcg/kg over 5 minutes, no muscle relaxant; have naloxone available.
  • Place the catheter mark at the cords (1 cm ≤26 weeks, 1.5 cm at 27–28, 2 cm ≥29), instil over 1 minute pausing for bradycardia or reflux, then aspirate the stomach for surfactant.
  • This is not an emergency procedure — if it is difficult, stop and use an alternative route.

8. Surfactant, Caffeine & Dosing

Medication & Dose Table

Verify every dose against your Neonatal Formulary and the product label. Doses below reflect commonly used regimens; product availability varies by unit.

AgentDose / routeIndicationNotes & monitoring
Poractant alfa (Curosurf®)200 mg/kg (2.5 mL/kg) first dose, via LISA / InSurE / ETT; round to nearest whole vial.First-line natural surfactant for RDS.Initial 200 mg/kg shows a survival advantage over 100 mg/kg or beractant. Warm to room temperature; invert gently (do not shake). Blood gas ~30 min after.
Poractant alfa — repeat100 mg/kg (1.25 mL/kg) every 12 h, up to two further doses.Continuing oxygen need of 30–40% with RDS, other causes excluded.Document indication and response for each dose.
Beractant / other natural surfactantsPer product label (e.g., beractant 100 mg/kg = 4 mL/kg); repeat per protocol.Alternative where poractant alfa is unavailable.Follow the specific product's dosing; do not interchange volumes between products.
Caffeine citrateLoading 20 mg/kg, then 5 mg/kg once daily, up to 10 if apnea persists (caffeine citrate salt; see 2.4).Apnoea of prematurity; facilitates CPAP success and LISA; reduces BPD.Load early in at-risk preterm infants. Monitor heart rate and tolerance.
LISA premedicationAtropine 0.02 mg/kg IV push + fentanyl 0.5–1 mcg/kg IV over 5 min; no muscle relaxant; naloxone available.Comfort during LISA while preserving respiratory drive.Sedation for LISA is unit-specific and controversial — heavier sedation risks apnoea and LISA failure.
Evidence & Source Differences
  • Dose: An initial poractant alfa dose of 200 mg/kg is favoured over 100 mg/kg; the European Consensus Guidelines support early rescue over prophylactic surfactant in the CPAP era.
  • Route: LISA/MIST reduces the need for mechanical ventilation and the risk of BPD and pneumothorax compared with InSurE/ETT, and is the preferred technique when the infant is breathing on CPAP.
  • Post-dose suction timing: sources vary (commonly avoid ETT suction for ~6–8 h after instillation) — follow local policy.
  • Other sources: European/UK protocols repeat poractant 100 mg/kg 6–12 h after the first dose (still ventilated, FiO₂ >0.30, MAP >7), use FiO₂ >0.30 on CPAP ≥6 as the threshold, start CPAP at 6–8, and mark the LISA catheter by length at the lips (5.5 cm at 23–24 weeks rising to 7.5 cm at 32–33 weeks). Surfactant beyond three doses remains consultant-led.
Default surfactant practice (Baylor Ed. 33)
  • CPAP first (AAP-endorsed): early CPAP with selective surfactant lowers death or BPD compared with intubation and prophylactic surfactant, even in ELBW infants. Give rescue surfactant to VLBW infants in respiratory distress needing >30% FiO₂ despite optimized CPAP; radiographic surfactant deficiency strengthens the case. Treating within the first 2 hours of established RDS reduces death, air leak and death or BPD compared with later treatment.
  • Poractant: 2.5 mL/kg (birth weight), then up to two further doses of 1.25 mL/kg at 12-hour intervals — repeat for a continuing oxygen need of 30–40%. Most infants need only one dose. If an outside hospital gave beractant and a second dose falls due, give poractant 1.25 mL/kg at that time. Confirm ETT position before dosing, and check an arterial gas soon after in ventilated infants, since compliance can improve within minutes.
  • Term infants with hypoxic respiratory failure (RDS, meconium aspiration, pneumonia, sepsis, some idiopathic PPHN): surfactant improves oxygenation and reduces ECMO. Benefit is greatest in ventilated infants with an oxygenation index of 15 on two consecutive measurements, and up to three doses may be needed. No benefit in CDH.
Default LISA protocol (Baylor Ed. 33)
  • Who: a preterm infant on CPAP or NIPPV with surfactant deficiency on film and/or clinically. Exclude and intubate instead if FiO₂ >70%, PCO₂ >65, or moderate to severe apnea.
  • CPAP escalation first:
    • FiO₂ <30% — continue CPAP 5–6.
    • FiO₂ ≥30% — raise CPAP by 1 every 30 minutes (every 20 minutes if FiO₂ ≥50%) up to CPAP 8.
    • Still ≥30% 30 minutes after reaching CPAP 8 (20 minutes if ≥50%) — perform LISA.
    • On NIPPV — give LISA when mean airway pressure ≥8 and FiO₂ ≥30% after 60–90 minutes of life.
  • Premedication: atropine 0.02 mg/kg IV push and fentanyl 0.5–1 mcg/kg IV over 5 minutes; no muscle relaxant.
  • Catheter: a 16G, 5.25-inch angiocath marked from its tip at 1 cm (≤26 weeks), 1.5 cm (27–28 weeks) or 2 cm (≥29 weeks). This mark sits at the vocal cords. A slight bend at the mark helps guide depth. Draw up surfactant 2.5 mL/kg in a 5 mL syringe with 1 mL of air behind it.
  • Technique:
    • If on NIPPV, turn the rate off and do the procedure on CPAP, leaving the mask on.
    • Use direct or video laryngoscopy, place the mark at the cords, then remove the blade.
    • Steady the catheter by pinching it at the lip — not against the palate, which dislodges it.
    • Instil over 1 minute, pausing for bradycardia or reflux, then flush with the air and remove the catheter.
  • Afterwards: wean CPAP or mean airway pressure quickly once FiO₂ is ≤25%. Aspirate the stomach and record any surfactant recovered. If much went into the stomach, consider repeating LISA or InSurE. Doses 2 and 3 can also be given by LISA, 12 hours apart.

9. Monitoring

Monitoring Table

What to watch, how often, the target, and the action if the parameter drifts.

ParameterFrequencyTargetAction if abnormal
Preductal SpO₂Continuous90–95% on oxygenTitrate FiO₂; reduce promptly after surfactant to avoid hyperoxia.
Work of breathing / FiO₂ trendContinuous / hourlyDecreasing after support & surfactantRising FiO₂ at CPAP ≥6 → surfactant; escalate if refractory.
Blood gas~30 min post-surfactant, then as neededImproving pH/PaCO₂, resolving acidosisAdjust CPAP/ventilator; persistent acidosis → reassess and escalate.
TemperatureOn admission & continuously if unstable36.5–37.5°CWarm; minimise heat loss during procedures/LISA.
GlucoseEarly & per protocolNormoglycaemiaTreat hypoglycaemia per unit protocol.
Chest signs / air leakWith any deteriorationSymmetric, stableTransilluminate; drain tension pneumothorax.
Cranial ultrasound (very preterm)Per unit schedule—Screen for IVH (see 9.2).

10. Contraindications & Precautions

Safety Cautions
  • Confirm airway before ETT surfactant: verify tube position (chest movement, bilateral air entry, CO₂ detection) — instilling surfactant down a malpositioned tube is harmful.
  • Watch for hyperoxia after dosing: compliance can improve within minutes; failure to wean FiO₂ risks oxidative injury and retinopathy.
  • Avoid over-distension / air leak: use the lowest effective pressures; reassess ventilation immediately after surfactant.
  • LISA cautions: requires spontaneous breathing — avoid heavy sedation; do not persist if difficult or if there is worsening respiratory acidosis despite optimal non-invasive support.
  • Do not routinely suction the ETT for several hours after instillation (per local policy) unless the tube is blocked.
  • Do not delay treating infection: pneumonia mimics RDS — give antibiotics until sepsis is excluded.
  • Transient dosing events: bradycardia/desaturation or reflux of surfactant during instillation — pause, recover, and resume slowly.

11. Escalation Criteria

Call the Consultant / Consider NICU Transfer When…
  • CPAP failure: rising FiO₂ (>0.30–0.40) and/or increasing work of breathing, recurrent apnoea, or respiratory acidosis despite optimal non-invasive support and surfactant.
  • Persistent or rising oxygen requirement after two surfactant doses, or oxygenation index trending toward 15–20 and above.
  • Suspected air leak, PPHN (pre-/post-ductal SpO₂ gap, labile oxygenation), or suspected congenital heart disease.
  • Need for high-frequency oscillatory ventilation, inhaled nitric oxide, or a level of support beyond the local unit's capability — refer to the neonatal transport service.
  • Any diagnostic uncertainty in an infant who is not improving as expected.
Parent Counselling Points
  • "Your baby's lungs are still developing and are low on a natural substance called surfactant, which keeps the tiny air sacs open. This is common in babies born early."
  • "We are supporting the breathing gently with pressure through the nose (CPAP) and giving oxygen only as needed. If the breathing effort increases, we can give surfactant directly into the lungs, often through a very thin tube without a breathing machine."
  • "Most babies improve over the next few days. We will keep you updated, and you can be involved in your baby's care, including skin-to-skin when your baby is stable."

12. Key Pearls

High-Value Clinical Pearls
  • Antenatal corticosteroids and early CPAP are the two interventions that most change the RDS trajectory — confirm steroid status at every preterm birth.
  • "CPAP first, surfactant early, extubate fast." Support non-invasively, treat surfactant deficiency promptly when the threshold is met, and return to CPAP quickly.
  • The FiO₂ >0.30 on CPAP ≥6 cmH₂O with increased work of breathing threshold is the practical trigger to give surfactant — don't wait for the infant to fail.
  • LISA lets you treat surfactant deficiency without committing the infant to mechanical ventilation — but it needs a breathing baby, so protect respiratory drive (caffeine, light or no sedation).
  • After surfactant, compliance improves fast — pre-emptively wean pressure and FiO₂ to prevent air leak and hyperoxia.
  • Pneumonia is the great imitator of RDS; always cover for infection until cultures allow you to stop.

13. Common Mistakes to Avoid

Pitfalls & Better Practice

The recurring errors in RDS care and what to do instead.

MistakeWhy it harmsBetter practice
Intubating a stable preterm infant just to give prophylactic surfactant.Exposes the infant to ventilator injury; routine prophylaxis is no longer recommended.Start CPAP; give early rescue surfactant only when the threshold is met.
Delaying surfactant while the FiO₂ climbs.Progressive atelectasis and hypoxaemia; late surfactant is less effective.Treat at FiO₂ >0.30 on CPAP ≥6 cmH₂O with increased work of breathing.
Attempting LISA in an inadequately breathing or heavily sedated infant.Apnoea and LISA failure requiring intubation.Ensure caffeine and spontaneous breathing; use minimal or no sedation.
Not weaning FiO₂/pressure after surfactant.Hyperoxia and air-leak risk as compliance suddenly improves.Pre-emptively reduce FiO₂ and pressures; recheck a gas.
Assuming all early distress is RDS.Missed pneumonia, pneumothorax, or duct-dependent CHD.Cover infection, transilluminate, and consider echocardiography.
Suctioning the ETT immediately after instillation.Removes freshly instilled surfactant.Avoid routine suction for several hours per local policy.

14. Board-Style High-Yield Summary

Key Takeaways
  • RDS = surfactant deficiency of prematurity; ground-glass film with air bronchograms and low lung volumes.
  • Antenatal steroids + early CPAP + selective early rescue surfactant is the lung-protective standard; routine prophylactic surfactant is not recommended.
  • Surfactant threshold: FiO₂ >0.30 on CPAP ≥6 cmH₂O with increased work of breathing.
  • Preferred route is LISA (thin catheter, breathing infant on CPAP); use InSurE/ETT if LISA not feasible.
  • Poractant alfa 200 mg/kg first dose (survival advantage over 100 mg/kg or beractant); repeat 100 mg/kg at 6–12 h if ongoing RDS; third dose consultant-only.
  • Target SpO₂ 90–95%; wean FiO₂ promptly after surfactant; load caffeine early.
  • Escalate for CPAP failure, refractory hypoxaemia, air leak, PPHN, or rising oxygenation index.

15. References

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