11.2 Respiratory Support for Preterm Infants

Why Preterm Lungs Demand a Different Touch

The preterm lung is not a small adult lung and not even a small term lung. Alveolarization is incomplete, surfactant is often deficient, chest wall compliance is high, and lung tissue is fragile. The same peak inspiratory pressure that barely moves a term infant’s chest can over-distend a 26-week lung and contribute to air leak or chronic lung injury. At the same time, under-ventilation leaves the infant hypoxic and bradycardic. Preterm respiratory support is therefore a balancing act: open the lung gently, support functional residual capacity, oxygenate thoughtfully, and escalate only as indicated.

You already know the universal NRP ventilation rules—PPV for apnea, gasping, or heart rate under 100; rate commonly 30–60 breaths per minute; rising heart rate as the best sign of effective ventilation. This section adds the preterm-specific modifiers: gentler pressure strategy, oxygen blending, CPAP for the breathing-but-distressed infant, and the conceptual place of surfactant after airway control.

Gentle Ventilation: Principle Before Device Brand

“Gentle ventilation” means:

• Use the lowest effective peak inspiratory pressure (PIP) that moves the chest and improves heart rate.
• Avoid exaggerated squeeze on a self-inflating bag or unnecessarily high T-piece set pressures.
• Watch for chest rise—visible movement, not dramatic bouncing.
• Correct mask leak and airway position (MR SOPA) before simply “turning up the pressure” forever.
• Prefer devices that allow controlled PIP and PEEP (T-piece resuscitator is often favored for preterm care when available and the team is trained).

Starting pressures

Exact initial PIP recommendations depend on gestational age band and the edition of guidance your course uses. Conceptually for NRP learning:

• Lower starting pressures are often appropriate for more preterm infants compared with larger late-preterm or term babies.
• Many programs teach an initial PIP near the mid-20s cm H2O range for larger preterm/term guidance and more cautious starts for smaller preterm lungs—then titrate to response.
• PEEP helps maintain functional residual capacity; apnea and surfactant deficiency make loss of FRC rapid when PEEP is absent.

Always follow current NRP provider materials and local unit policy for the numeric starting point you use in practice. On exams, the safer concept answer is: start thoughtfully, avoid excessive pressure, escalate if chest is not moving and MR SOPA corrections fail, and never leave ineffective ventilation uncorrected.

Oxygen Blender: Hyperoxia Is Not Free

Term resuscitation historically drifted toward 100% oxygen; modern neonatal practice—and NRP teaching—emphasizes blended oxygen and pulse oximetry targets. Preterm infants are especially vulnerable to oxygen toxicity and oxidative stress.

Practical blender rules for the preterm delivery

1. Have a blender in the room before birth—do not discover you only have pure oxygen mid-code.
2. Start lower than 100% for many preterm infants. A commonly taught initial range for very preterm newborns is about 21–30% FiO2, then titrate to the minute-of-life SpO2 targets. Exact start FiO2 follows current NRP recommendations and local policy—memorize the principle of “lower start + titrate,” not a single number divorced from your course materials.
3. Place a preductal pulse oximeter (right hand/wrist) early.
4. Titrate oxygen to the published target SpO2 table by minutes of life, not to “pink as possible as fast as possible.”
5. If the infant requires chest compressions, oxygen strategy escalates per algorithm (commonly high/100% oxygen during compressions—know current NRP wording). Compressions are a different phase than initial preterm transition support.

Free-flow oxygen vs PPV vs CPAP

• Apnea / gasping / HR < 100 → PPV with blended gas, not free-flow alone.
• Breathing + HR ≥ 100 + labored breathing or low SpO2 → oximetry, titrated oxygen, and strong consideration of CPAP.
• Free-flow oxygen does not create PEEP or reliably inflate surfactant-deficient lungs.

CPAP for Labored Breathing With Adequate Heart Rate

Continuous positive airway pressure is a cornerstone of modern preterm respiratory transition. Many preterm infants initiate breathing but show grunting, retractions, flaring, and desaturation because alveoli collapse at end-expiration without adequate functional residual capacity.

When CPAP fits

• Spontaneous respiratory effort is present.
• Heart rate is adequate (not in the PPV/bradycardia pathway).
• Work of breathing is increased or oxygenation is inadequate for minute of life despite free-flow oxygen titration.

CPAP stents airways open, improves oxygenation, and may reduce the need for immediate intubation in selected infants. It is not a substitute for PPV when the infant is apneic or the heart rate is below 100 after initial steps.

Interface and teamwork

• Use an appropriately sized mask or prongs per device and training.
• Maintain midline head position and gentle jaw support as needed.
• Watch for improvement in work of breathing and SpO2; prepare to escalate to PPV if apnea or bradycardia develops.

On scenario questions, a 30-week infant with HR 140, grunting, and low SpO2 is a CPAP/oxygen titration candidate—not automatic full chest compressions.

PPV Still Saves Preterm Lives

Gentle does not mean passive. If the preterm infant is apneic, gasping, or has HR < 100 after initial steps, start positive-pressure ventilation immediately. Effective ventilation remains the most important action for most compromised newborns—preterm included.

Keys during preterm PPV

• Correct mask size (cover mouth and nose; avoid eyes).
• Sniffing position with slight neck extension appropriate to a large preterm occiput—often a shoulder roll helps.
• Rate ~30–60/min.
• Reassess heart rate frequently; rising HR = best indicator of success.
• Apply MR SOPA when ventilation is ineffective before stacking endless pressure increases.
• Consider early alternative airway (endotracheal tube or laryngeal mask per indication and size feasibility) if mask ventilation fails or compressions are needed.

Avoid the “blow-off” extremes

Surfactant: Concept-Level Pathway

Surfactant replacement is a NICU/advanced respiratory therapy that appears in NRP at a conceptual level for preterm resuscitation:

• Surfactant deficiency drives respiratory distress syndrome (RDS) risk.
• When surfactant is indicated, it is typically given after the airway is secured (commonly via endotracheal tube using unit protocols).
• Delivery-room surfactant strategies vary (prophylactic vs early rescue; INSURE-type approaches; less-invasive methods in some units).
• For NRP exams, know: do not delay establishing effective ventilation to “wait for surfactant”; secure the airway and ventilate first, then follow local indications for surfactant once the infant is stabilized enough for the procedure pathway.

You are not expected to memorize every brand dose chart in a general NRP section, but you are expected to understand that surfactant is part of the preterm respiratory armamentarium after airway control when clinically indicated.

Monitoring Bundle for Preterm Respiratory Care

Pair respiratory support with:

• ECG when resuscitation extends beyond brief support (accurate HR).
• Preductal SpO2 for oxygen titration.
• Temperature protection under plastic/warmer (prior section).
• Clear role assignment: one person owns the airway/device, another announces HR and SpO2, another prepares advanced airway/surfactant pathway if needed.

Integrated Scenarios

Scenario A — CPAP path. 31-week infant, crying with deep retractions, HR 150, SpO2 below target for 4 minutes of life on 30% free-flow oxygen. → Continue warmth, apply CPAP, titrate FiO2 to targets, prepare for escalation if apnea/bradycardia appears.

Scenario B — PPV path. 28-week infant, apneic after plastic wrap and positioning, HR 70. → Start PPV with blender (not free-flow alone), gentle effective pressures, reassess HR; do not “CPAP an apneic baby.”

Scenario C — Pressure titration. Mask PPV with no chest rise, HR falling. → MR SOPA (mask seal, reposition, suction if needed, open mouth, pressure increase, alternative airway)—not immediate epinephrine.

Scenario D — Hyperoxia trap. Very preterm infant pink with SpO2 99% at 3 minutes on 100% oxygen without blender titration. → Wean FiO2 toward target range; avoid unnecessary hyperoxia.

Scenario E — Surfactant concept. Intubated extremely preterm infant with ongoing high oxygen need and clinical RDS after airway secured. → Surfactant per local protocol once airway is controlled; ventilation and oxygenation come first.

Exam Mindset Checklist

• Gentle, effective ventilation—lowest pressure that works.
• Blender + SpO2 targets; many very preterm starts below 100% (commonly taught ~21–30%—follow current NRP/local policy).
• CPAP for labored breathing with spontaneous effort and adequate HR.
• PPV still for apnea/gasping/HR < 100.
• Surfactant after airway secured when indicated (concept level).

One-sentence anchor: open fragile preterm lungs gently with blended oxygen, use CPAP when they breathe with distress, and still deliver prompt PPV whenever apnea, gasping, or bradycardia under 100 demands it.