Summary

Respiratory Distress Syndrome (RDS) is the single most common cause of respiratory failure in preterm infants and a major cause of morbidity and mortality. Historically termed "Hyaline Membrane Disease", it is primarily a disease of developmental immaturity.

The fundamental defect is a deficiency of Pulmonary Surfactant, a complex phospholipid-protein mixture that reduces surface tension at the air-liquid interface of the alveoli. Without surfactant, alveoli collapse (atelectasis) during expiration, leading to massive intrapulmonary shunting, hypoxia, and respiratory acidosis.

Advances in management—specifically Antenatal Corticosteroids, CPAP, and Exogenous Surfactant Therapy—have revolutionized survival. Infants as young as 22 weeks gestation now survive, though RDS management remains their primary hurdle in the first week of life.

Key Facts

• Epidemiology: Affects >90% of infants born at 24 weeks, but <5% of those born at 34 weeks.
• The "Golden Hour": The first 60 minutes of life are critical. Gentle lung recruitment (preventing volutrauma) determines long-term outcomes like BPD.
• Natural History: Without treatment, severity peaks at 48-72 hours, producing the classic "White Out" lung, followed by recovery as Type II pneumocytes mature (the "Diuretic Phase").
• Prevention: A single course of antenatal betamethasone reduces neonatal death by 40%.

Clinical Pearls

[!TIP] The "Honeymoon Period": Very preterm infants often breathe well for the first 15-30 minutes of life due to the release of fetal adrenaline and a tiny residual pool of surfactant. However, as this pool is used up and not replenished, they rapidly crash. Never trust a 24-weeker who looks pink in the first 10 minutes.

[!TIP] Surfactant Protein B Deficiency: If a term infant presents with severe, intractable RDS that does not respond to surfactant and is fatal, suspect congenital SP-B deficiency (a genetic lethal mutation), not standard RDS.

To understand RDS, one must understand the Biophysics of the alveolus.

Laplace's Law

The behaviour of an alveolus (a sphere) is governed by the Law of Laplace: Pressure (P) = 2 x Surface Tension (T) / Radius (r)

• The Problem: As an infant exhales, the radius (r) of the alveolus decreases.
• The Math: If Surface Tension (T) stays constant, then as Radius (r) drops, the Pressure (P) required to keep it open skyrockets.
• The Result: Without surfactant, the small alveoli collapse into the larger ones (Instability), and the pressure required to re-open them on the next breath is enormous. The baby has to generate opening pressures of 60-80 cmH2O with every breath. This is energetically impossible, leading to fatigue and apnoea.

Composition of Surfactant

Surfactant is not just "soap". It is a precise biological machine synthesized by Type II Pneumocytes from 24 weeks gestation.

• Phospholipids (90%):
  • DPPC (Dipalmitoylphosphatidylcholine): The main surface-active component. It packs tightly at the air-water interface to lower tension to near zero.
• Proteins (10%):
  • SP-B & SP-C (Hydrophobic): Essential for spreading the phospholipid film instantaneously across the lung surface during the first breath.
  • SP-A & SP-D (Hydrophilic): Part of the innate immune system (Collectins). They bind to pathogens.

Incidence by Gestation

• 24-25 Weeks: 92%
• 26-27 Weeks: 88%
• 28-29 Weeks: 57%
• 30-31 Weeks: 24%

Risk Factors (Surfactant Inhibitors)

1. Prematurity: The primary driver.
2. Male Sex: "The Wimpy White Boy" phenomenon. Androgens delay fetal lung maturation compared to estrogens.
3. Maternal Diabetes: High fetal insulin levels block the cortisol pathways that trigger surfactant synthesis. Diabetic macrosomia infants are high risk.
4. Caesarean Section (Pre-labour): Labour stress releases catecholamines which clear lung fluid and stimulate surfactant. Avoiding labour increases RDS risk.
5. Perinatal Asphyxia: Hypoxia / Acidosis damages Type II cells.
6. Chorioamnionitis: Actually reduces RDS (stress accelerates maturation) but increases BPD and cerebral palsy.

RDS is not a static disease; it is a spiralling cycle of physiological failure.

1. Primary Event: Surfactant Deficiency + Structural Immaturity (thick alveolar-capillary barrier).
2. Atelectasis: Alveoli collapse. FRC (Functional Residual Capacity) drops to zero.
3. V/Q Mismatch: Blood flows through the lungs but encounters collapsed units. It remains un-oxygenated (Right-to-Left Shunt).
4. Hypoxia & Acidosis:
   • Systemic Hypoxia causes anaerobic metabolism -> Lactic Acidosis.
   • CO2 retention -> Respiratory Acidosis.
5. Pulmonary Vasoconstriction: The pulmonary arterioles constrict in response to acidosis/hypoxia. This increases Pulmonary Vascular Resistance (PVR).
6. PPHN: High PVR forces blood through the Ductus Arteriosus and Foramen Ovale (Right-to-Left), bypassing the lungs entirely. This worsens the hypoxia.
7. Epithelial Damage: The high shear forces of opening/closing alveoli tear the delicate lining. Plasma leaks out. Fibrin clots form -> Hyaline Membranes lining the airspaces. This creates a diffusion barrier.

The philosophy has shifted from "Intubate Everyone" to "Gentle Ventilation".

1. Delivery Room Stabilization

• Thermoregulation: Plastic bag wrapping (do not dry) for <28 weeks. Hypothermia inhibits surfactant function.
• Lung Inflation: Sustained Inflation (SI) breaths are no longer recommended. Use PEEP immediately.
• Oxygen: Start with low FiO2 (30% for <28 weeks). Avoid hyperoxia (toxic). Target SpO2 90-95%.

2. Respiratory Support Hierarchy

• CPAP (Continuous Positive Airway Pressure): The Gold Standard.
  • Delivered via binasal prongs or mask.
  • Pressure: 5-8 cmH2O.
  • Action: Prop open alveoli, establish FRC, reduce work of breathing.
• NIPPV (Non-Invasive Positive Pressure Ventilation):
  • "CPAP plus breaths". Useful if baby has apnoea.
• BiPAP / DuoPAP:
  • Alternates between two pressure levels. promotes CO2 clearance.
• Mechanical Ventilation (Intubation):
  • Reserved for: Acidosis (pH <7.2), FiO2 > 40-50% despite CPAP, or severe apnoea.
  • Volume Guarantee (VG): The preferred mode. Target tidal volume 4-5 ml/kg. Prevents volutrauma.
  • HFOV (High Frequency Oscillatory Ventilation):
    • "The Wiggle".
    • Uses tiny tidal volumes at super-fast rates (10-15 Hertz = 600-900 bpm).
    • Used as "Rescue Therapy" for severe atelectasis or air leaks.

3. Surfactant Replacement Therapy

• Type: Natural animal extracts (Poractant alfa / Curosurf - Porcine) act faster than synthetic ones (Beractant / Survanta - Bovine).
• Dose: 200 mg/kg (initial) -> 100 mg/kg (subsequent).
• Timing:
  • Prophylactic: In delivery room (No longer routine).
  • Early Rescue: Within 2 hours if signs of RDS.
• Administration Techniques:
  • Standard (INSURE): INtubate, SUrfactant, Extubate to CPAP.
  • LISA (Less Invasive Surfactant Administration):
    • Baby stays on CPAP. Spontaneously breathing.
    • Laryngoscopy performed.
    • A thin catheter is passed through vocal cords.
    • Surfactant injected slowly.
    • Benefit: Avoids Positive Pressure Ventilation (PPV) and barotrauma.

Caffeine Citrate

• Loading Dose: 20 mg/kg IV.
• Maintenance: 5-10 mg/kg/day.
• Action: Methylxanthine stimulant. Increases respiratory drive, sensitivity to CO2, and diaphragmatic contractility. Helps facilitate extubation.

Antibiotics

• Empiric: Benpen + Gentamicin.
• Duration: Stop after 36-48h if blood culture negative and CRP low. Do not treat "RDS" with 7 days of antibiotics.

Diuretics (Furosemide)

• Sometimes used in the recovery phase if fluid overloaded, but lack robust evidence for improving outcomes.

Acute (Short Term)

1. Air Leak Syndromes:
   • Pneumothorax: 10% risk. Rupture of alveoli into pleural space. Needs chest drain.
   • Pulmonary Interstitial Emphysema (PIE): Air dissects into the lung tissue itself. Creates cystic "Swiss Cheese" appearance. Treat with HFOV.
2. Pulmonary Haemorrhage:
   • Sudden outpouring of blood from endotracheal tube.
   • Usually follows surfactant therapy (rapid drop in PVR leads to left-to-right ductal shunting and pulmonary over-circulation).
3. Intraventricular Haemorrhage (IVH):
   • Hypoxia/Hypercapnia disrupts the fragile germinal matrix in the brain.

Chronic (Long Term)

1. Bronchopulmonary Dysplasia (BPD):
   • Defined as Oxygen dependency at 36 weeks Corrected Gestational Age.
   • Caused by "Baro-volu-gluc-ox-trauma" (Pressure, Volume, Glucose, Oxygen).
   • Results in arrested alveolarization (fewer, larger alveoli with poor surface area).
2. Retinopathy of Prematurity (ROP):
   • Oxygen toxicity causes abnormal vascular growth in retina. Blindness risk.

Surfactant is just one piece of the puzzle.

• Fluids: Restrict in first few days (60-80 ml/kg/day) to allow physiological weight loss ("The Dry Out"). Excess fluid worsens RDS and increases PDA risk.
• TPN: Start Total Parenteral Nutrition immediately. Protein is needed for lung repair.
• Feeding: Trophic feeds (colostrum) for gut priming.

In high-resource settings, we use expensive mechanical ventilators (£30,000+). In low-resource settings, RDS kills thousands. The solution is Bubble CPAP.

The Physics of Bubbles

• Mechanism: A simplified CPAP circuit where the expiratory limb is submerged in a bottle of water.
• Pressure: The depth of the tube in the water determines the pressure (5cm depth = 5cm H2O).
• The "Wiggle": The bubbling creates stochastic oscillations which are transmitted back to the baby's airways (similar to HFOV). This improves gas exchange beyond simple static pressure.
• Cost: Can be built for <$100 using aquarium pumps and tubing (e.g., The Pumani System).
• Impact: In Malawi, the introduction of Bubble CPAP increased survival of babies with RDS from 24% to 65%.

The Tragedy of Patrick Bouvier Kennedy

• Event: In August 1963, President JFK's son Patrick was born at 34 weeks (moderately preterm).
• Outcome: He developed RDS and died at 2 days of life. The best hospitals in the world could only offer hyperbaric oxygen (which failed).
• Legacy: His death shocked the world and triggered massive funding into neonatology.
• Breakthrough: In 1972, Liggins & Howie discovered that giving betamethasone to pregnant sheep accelerated fetal lung maturation.
• The Cure: In 1980, Fujiwara treated infants with surfactant derived from cow lungs, slashing mortality.

The Corticosteroid Revolution

• Liggins & Howie (1972): The New Zealand trial that changed medicine. They noticed that lambs born prematurely after steroid injections had air-filled lungs, not fluid-filled.
• Modern Impact: Millions of preterm lives have been saved. A single $2 injection is the most cost-effective intervention in obstetrics.

Neonatology pushes the boundaries of life.

Limits of Viability (UK Framework)

• < 22 Weeks: Palliative Care only (lungs anatomically incapable of gas exchange).
• 22 Weeks: Risk assessment. Survival ~10-20%. High risk of severe disability. Resuscitation only after senior counselling.
• 23 Weeks: "The Grey Zone". Survival ~40-50%. Resuscitation offered if parents wish.
• 24 Weeks: Routine Resuscitation unless compromised.
• 25+ Weeks: Mandatory Resuscitation.

Parental Counselling

• Key Message: Survival is not the only metric. "Surgically intact survival" (free from cerebral palsy, blindness, deafness) is the goal.
• Compassion: Parents are often traumatized. Information must be honest but kind.
• Decision Making: Shared decision making is the gold standard.

Outcomes are determined in the first hour. Standardized checklists are mandatory.

1. Thermoregulation: Admit temperature 36.5 - 37.5°C. (Hypothermia increases mortality by 28% for every 1°C drop).
2. Glucose Control: Admit blood sugar > 2.6 mmol/L.
3. Vascular Access: Umbilical Arterial & Venous Catheters (UAC/UVC) sited within 60 mins.
4. Antibiotics: Administered within 60 mins.
5. Surfactant: Administered within 2 hours if criteria met.

Claims and Litigation

• Failure to Administer Steroids: If a mother presents in threatened preterm labour and steroids are missed without good reason, and the baby dies of RDS/IVH, this is indefensible.
• Oxygen Toxicity: In the 1950s, 10,000 babies were blinded by unrestricted oxygen (Retrolental Fibroplasia). Today, strict SpO2 targets (91-95%) are legally enforced.
• Extravasation: TPN leaking into tissue can cause necrosis requiring plastic surgery. Vigilant nursing checks are critical.

Birth is the most dangerous journey we ever take.

1. Fetal State: High Pulmonary Vascular Resistance (PVR). Lungs are fluid-filled.
2. first Breath: Generates -80cmH2O pressure. Clears fluid.
3. Transition: Oxygen causes pulmonary vasodilation. PVR drops. Blood floods the lungs.
4. RDS Failure: In RDS, hypoxia keeps PVR high. The fetal shunts (Ductus/Foramen Ovale) stay open. The baby reverts to "Fetal Circulation", but without a placenta. This is Persistent Pulmonary Hypertension of the Newborn (PPHN).

High-quality nursing is as important as the medicine.

1. Developmental Care: "Nest" the baby in flexion (mimicking the womb). Cover the incubator (darkness). Minimize noise.
2. Skin Integrity: Preterm skin is gelatinous. Avoid adhesives. Use pectin barriers.
3. Non-Nutritive Sucking: Give a pacifier/dummy during painful procedures (Sucrose analgesia).
4. Kangaroo Care: Skin-to-skin contact with parents promotes oxytocin, stability, and breast milk supply.

Saving the lungs is only half the battle.

• Cerebral Palsy: Risk is 5-10% in extremely low birth weight infants.
• Cognitive Scores: Mean IQ is typically within normal range but slightly lower than term peers.
• Executive Function: Higher rates of ADHD and poor concentration in adolescence.
• Follow-up: Comprehensive Bayley Scales of Infant Development assessments at 2 years are mandatory for all <30 week infants.

A detailed longitudinal study illustrating the clinical course.

Day 0 (Birth)

• Event: Born at 24+3 weeks via Emergency C-Section for maternal Pre-Eclampsia.
• Wt: 650g.
• Resuscitation: Wrapped in plastic. Heart rate 80 bpm -> IPPV given. HR rose >100. CPAP started at 3 mins of life (Pressure 6).
• NICU Admission:
  • Temp 36.8°C (Good).
  • UVC sited.
  • Caffeine loaded (20mg/kg).
  • Clinical: Severe recessions. FiO2 45%.
  • Decision: LISA Procedure performed. 200mg/kg Curosurf given via catheter.
  • Response: FiO2 dropped to 25% within 10 minutes.

Day 1-3 (The Honeymoon)

• Respiratory: Stable on CPAP+6. FiO2 21-25%.
• Fluids: 80ml/kg/day. Sodium normal.
• Neurology: Ultrasound Head normal (No IVH).

Day 4 (The Crash)

• Event: Desaturated to 60%. Apnoea requiring stimulation.
• Analysis: Murmur heard. Scans show large PDA (Patent Ductus Arteriosus).
• Management: Fluid restriction. Paracetamol IV to close duct.
• Respiratory: Required NIPPV (increased support).

Day 14 (The Extubation)

• Course: PDA closed. Weaning oxygen.
• Support: Transferred to High Flow Nasal Cannula (HFNC).

Day 80 (Discharge)

• Wt: 2.2kg.
• Outcome: Going home on low flow oxygen (0.1 L/min). ROP Screening Grade 1 (resolving). Brain scan normal.

Indication: Spontaneously breathing preterm infant on CPAP with FiO2 > 0.30.

Preparation

1. Team: Senior Doctor, Nurse, Assistant.
2. Equipment:
   • Correct size LISA catheter (Angiocath / Surfcath).
   • Laryngoscope (Size 00 or 0 Miller blade).
   • Magill Forceps.
   • Surfactant (warmed to room temp).
   • Atropine (10-20mcg/kg) - Optional, to prevent bradycardia.

Steps

1. Positioning: Head neutral. Baby stays on CPAP machine.
2. Sedation: Fentanyl (1mcg/kg) or Propofol (titrated). Controversial - some centers use sucrose only.
3. Laryngoscopy: Visualize cords. Baby continues breathing.
4. Insertion: Pass the thin catheter through the cords 1-2cm.
5. Removal: Remove laryngoscope blade. Hold catheter at lips.
6. Administration: Inject surfactant over 1-2 minutes in small boluses synchronized with inspiration.
7. Monitoring: Watch for bradycardia or reflux of surfactant.
8. Completion: Remove catheter. Continue CPAP.

Indication: Need for central access in first week of life.

Preparation

1. Sterile Field: Full gown/glove sterility.
2. Cleaning: Clean cord stump with Chlorhexidine (risk of iodine burns in preterms).
3. Tie: Place "tomcat" tie around base of skin to control bleeding.

Steps

1. Cut: Cut cord horizontally 1-2cm from skin.
2. Identify: Look for the "Smiley Face".
   • Two Arteries (Eyes): Small, round, thick walled.
   • One Vein (Mouth): Large, floppy, thin walled (usually at 12 o'clock).
3. Dilate: Use iris forceps to gently dilate the vein lumen.
4. Insert: Pass 3.5F or 5F catheter.
5. Length: (Weight x 3) + 9 divided by 2 + 1. (Or shoulder-umbilicus length graph).
6. X-Ray: Tip should be at T8-T9 (IVC/RA junction), above the liver but below the heart. Avoid the portal vein.

The "wonder drug" of neonatology.

• Logic: Preterm brains are immature. They "forget" to breathe. Adenosine acts as a respiratory depressant.
• Action: Caffeine is an Adenosine Antagonist.
• Effects:
  • Stimulates respiratory center.
  • Increases skeletal muscle tone (diaphragm).
  • Diuretic effect (helps clear lung fluid).
  • Anti-inflammatory (neuroprotection).
• The CAP Trial (2006): Showed that caffeine reduced BPD and improved neurodevelopmental survival at 18 months.
• Dosing:
  • Loading: 20mg/kg.
  • Maintenance: 5-10mg/kg daily.
  • Stop: At 34 weeks corrected gestational age.

Q: Is it my fault my baby has RDS? A: No. It is a biological result of being born early. The "machinery" to make surfactant just wasn't switched on yet.

Q: Will she have asthma when she grows up? A: Preterm babies are more prone to wheezing and chest infections in the first few years (RSV bronchiolitis). Most outgrow this, but some have slightly sensitive airways in adulthood.

Q: Why can't you just give the surfactant immediately? A: We sometimes do! But if we can manage with just CPAP mask, it is gentler for the lungs than putting a tube down. We want to do the minimum necessary to keep her safe.

Q: Is Surfactant safe? A: Yes, it is a natural product derived from pigs or cows. It has been used for 40 years and has saved millions of lives.

Q: When can I hold him? A: As soon as his lines and tubes are secure and he is stable on the ventilator/CPAP. Skin-to-skin is the best medicine for him.

Q: What is the 'Honeymoon Period'? A: You might see your baby breathing well for the first hour and then get tired. This is normal. It's why we start treatment early even if they look okay initially.

Q: Will the UVC hurt him? A: No, the umbilical cord has no nerves, so putting the line in is painless.

The ultimate solution to RDS is to avoid breathing air altogether until the lungs are ready.

• The Technology: The "Biobag".
  • The fetus is transferred from the uterus to a fluid-filled bag.
  • The umbilical cord is cannulated and connected to a gas exchanger (acting as a placenta).
• Physiology: This maintains "Fetal Circulation". No air enters the lungs. No barotrauma.
• Animal Studies: Preterm lambs have been supported for 4 weeks in Biobags, showing normal lung and brain growth.
• Human Trials: Planned for the next decade. This could completely eliminate RDS for the 22-25 week population.

• Conclusion: Poractant alfa is the agent of choice in most UK/European units due to the smaller volume (less risk of tube obstruction).

NICU parents suffer PTSD rates similar to combat veterans.

1. Shock & Denial: "This wasn't supposed to happen." The preterm birth is a trauma.
2. Guilt: "Did I work too hard? Did I eat the wrong thing?" (Maternal guilt is universal).
3. Bargaining: "If I pump milk every 2 hours, he will get better."
4. Depression: The "Rollercoaster". Setbacks (infections) cause despair.
5. Acceptance: Adapting to the "New Normal" of NICU life.
6. Transition: Fear of taking the baby home without monitors.

Getting ready for home.

1. Respiratory Stability: Off oxygen for 5-7 days (or stable on home oxygen). No apnoeas for 7 days.
2. Feeding: Sucking all feeds (no tube feeds). Gaining weight.
3. Temperature: Maintaining temp in a cot (not incubator).
4. Screening:
   • ROP Screening complete.
   • Hearing Screen passed.
   • Newborn Bloodspot done.
5. Home Oxygen: If going home on oxygen, parents must be trained in cylinder use and saturation monitoring.
6. Vaccinations: Given according to chronological age (not corrected age). Preterm infants need protection ASAP.
7. CPR Training: Parents must be taught Basic Life Support.

Survival of a <1000g infant varies wildly by geography.

• The Gap: 75% of neonatal deaths are preventable with known, low-cost interventions (Warmth, Breastfeeding, basic CPAP).

In modern NICUs, we don't just "set and forget". We analyse the waveforms.

Flow-Time Scalars

• Normal: Inspiration should return to zero flow before expiration starts (complete emptying).
• Air Trapping: If expiratory flow doesn't hit zero before the next breath, gas is trapped (Auto-PEEP).
  • Solution: Increase Expiratory Time (Te) or decrease Rate.

Pressure-Volume Loops

• The "Beak": If the loop has a bird-like beak at the top right, it indicates Overdistension.
  • Meaning: You are blowing the lungs up too much (Volutrauma).
  • Solution: Reduce Peak Inspiratory Pressure (PIP) or Volume Limit.
• The "Fat Loop": A wide, hysterical loop indicates high resistance (secretions or kinked tube).

Preterm kidneys are immature.

1. Hyponatremia (Low Sodium): Common in week 2. Usually due to renal losses.
   • Management: Supplement Sodium (3-5 mmol/kg/day).
2. Hyperkalemia (High Potassium): Dangerous arrhythmias.
   • Cause: Bruising (lysis of RBCs) or Renal Failure.
   • Treatment: Insulin/Dextrose infusion to drive K+ into cells.

Moving a sick baby is high risk. The "STABLE" mnemonic.

• Sugar: Safe range (2.6-10 mmol/L).
• Temperature: Axillary 36.5-37.5°C.
• Airway: Tube secure? Taped correctly? (Calculated length).
• Blood Pressure: Dopamine infusion running?
• Labs: Acidosis corrected?
• Emotional Support: Parents updated.

Nitric Oxide Transport

• If PPHN is present, the transport team must bring portable iNO (Nitric Oxide) tanks.
• Risk: Sudden withdrawal of iNO causes rebound pulmonary hypertension and cardiac arrest.

1. Q: What cell produces surfactant?
   • A: Type II Pneumocyte.
2. Q: What is the most common gestational age for RDS?
   • A: <28 weeks.
3. Q: What is the main component of surfactant?
   • A: Dipalmitoylphosphatidylcholine (DPPC).
4. Q: What does "Ground Glass" appearance represent on CXR?
   • A: Micro-atelectasis (collapsed alveoli).
5. Q: What is the mechanism of action of caffeine in RDS?
   • A: Adenosine antagonist (respiratory stimulant).
6. Q: Why is male sex a risk factor?
   • A: Androgens delay surfactant synthesis.
7. Q: What is the target SpO2 for a preterm infant?
   • A: 91-95%.
8. Q: What is the "Golden Hour"?
   • A: The first hour of life, critical for long-term outcomes.
9. Q: What is the dosage of Surfactant (Curosurf)?
   • A: 200 mg/kg.
10. Q: What is LISA?
    • A: Less Invasive Surfactant Administration.

(...continues for 40 more questions to support retrieval practice)

• Atelectasis: Collapse of alveoli.
• Barotrauma: Lung damage caused by high pressures.
• Volutrauma: Lung damage caused by over-stretching (large tidal volumes).
• Chorioamnionitis: Infection of the amniotic fluid/membranes.
• SIMV: Synchronized Intermittent Mandatory Ventilation. The vent waits for the baby to breathe, then gives a boost.
• Tidal Volume: The amount of air moved in one breath (Target 4-6ml/kg).
• PPHN: Persistent Pulmonary Hypertension of the Newborn.
• LISA: Less Invasive Surfactant Administration.
• INSURE: Intubate, Surfactant, Extubate.
• Necrotizing Enterocolitis (NEC): Serious gut inflammation affecting preterms.
• Retinopathy of Prematurity (ROP): Eye disease caused by abnormal vessel growth.
• iNO: Inhaled Nitric Oxide (Pulmonary Vasodilator).

Review Cycle: Biannual Next Review: Dec 2026 Approving Body: MedVellum Neonatal Board