#169: A Breath of Fresh Air: Non-invasive Respiratory Support

February 25, 2026 | By Sam Masur

Audio

Get ready to breathe easy with this lively Cribsiders episode on non-invasive respiratory support in pediatrics! We’re joined by the incredible Dr. Michelle Perez from Montefiore, who breaks down the fundamentals of CPAP, BiPAP and HFNC. From choosing the right modality to knowing when it’s time to escalate, this episode will help you support little lungs without jumping straight to the tube. 

Non-Invasive Respiratory Support Pearls

1. Oxygenation is the process of moving oxygen from the lungs into the blood and then tissues, while ventilation is the process of moving oxygen into the lungs while removing carbon dioxide out from the lungs. 
2. Respiratory distress is a clinical definition of tachypnea, retractions, and difficulty speaking/feeding, whereas respiratory failure is a physiologic definition of PaO₂ < 60 mmHg or SpO₂ < 88% on room air. 
3. The starting settings for the non-invasive respiratory supports are: 1.5L/kg/min for HFNC, 5cm H2O for CPAP and 10/5cm HcO for BiPAP. 
4. Non-invasive respiratory support should not be used in children with apnea, GI bleeds, vomiting, or seizures. 
5. Parents can help monitor their child at home by using nasal suctioning and learning how to count a respiratory rate to know when it’s time to seek medical care. Warning signs to watch for include rapid breathing, chest retractions, poor feeding, decreased urine output, and increasing fatigue.

Non-Invasive Respiratory Support Notes 

Why Children Need Escalated Respiratory Support

Respiratory illness is the most common cause of pediatric hospital and ICU admissions (AAP, 2014). Escalation beyond room air is indicated when:

• Hypoxemia persists despite suctioning/supportive care
• Increased work of breathing (retractions, nasal flaring, grunting) does not improve
• There is failure of low-flow oxygen
  

Key principle: Always clarify what problem you are treating:

• Hypoxemia (oxygenation failure)
• Hypercarbia (ventilatory failure)
• Or both

Respiratory Distress vs. Respiratory Failure

Respiratory Distress (Clinical)

Observable exam findings:

• Tachypnea
• Retractions / accessory muscle use
• Nasal flaring, grunting
• Difficulty feeding or speaking
  

Acute Respiratory Failure (Physiologic)

• Hypoxic Respiratory Failure: PaO₂ < 60 mmHg or SpO₂ < 88% on room air
• Hypercarbic Respiratory Failure: PaCO₂ > 45 mmHg or pH < 7.35 (Pediatric Critical Care Medicine, 2015)

In pediatrics, ABGs are not always available—trend the exam and vitals (Lancet Respiratory Medicine, 2019). 

High-Flow Nasal Cannula (HFNC)

Heated, humidified oxygen is delivered via a nasal cannula in an open (non-closed) system, with the ability to independently adjust both the flow rate and the fraction of inspired oxygen (FiO₂).

Why HFNC Works

High-flow nasal cannula therapy facilitates upper airway dead space washout, which is particularly important in infants, allows for more consistent delivery of FiO₂, improves patient comfort and mucociliary clearance, and may reduce bronchospasm; however, it does not reliably provide positive end-expiratory pressure, especially when the mouth is open (expert opinion).

Initial HFNC Settings

Flow:

• Start at 1.5 L/kg/min (NEJM, 2018)
• Can increase to 2 L/kg/min if no improvement
• Higher flows (>2 L/kg/min) show no proven benefit (Cochrane, 2024)
• Treatment failure risk increases if starting <1.5 L/kg/min

FiO₂:

• Titrate to goal SpO₂ ~88–92% (higher if concern for shock, AMS, poor perfusion) (AAP, 2014)

Objective Monitoring on HFNC

Improvement should occur within 2–4 hours (NEJM, 2018). A worsening exam does not mean the patient should be given more time. It’s better to escalate early (Lancet Respiratory Medicine, 2019). Use objective measures:

• Respiratory rate
• Heart rate
• Retractions (location & severity)
• Feeding tolerance
• Ability to vocalize
• Wheeze/air entry
  

Common scoring tools:

• Seattle Bronchiolitis Score
• PEWS (less disease-specific)

When HFNC Is Most Helpful

High-flow nasal cannula is most helpful in bronchiolitis, where it has the strongest supporting evidence (Cochrane, 2024). It is particularly beneficial in infants with a high secretion burden, increased upper airway dead space, and significant work of breathing. In contrast, HFNC is less effective in older children with primary lung pathology and in patients with severe hypercarbic respiratory failure.

CPAP vs BiPAP

CPAP (Continuous Positive Airway Pressure)

Continuous positive airway pressure delivers a single constant pressure throughout the respiratory cycle, improves mean airway pressure, and is best suited for pure hypoxemia, with a typical starting pressure of 5 cm H₂O (Pediatric Critical Care Medicine, 2006).

BiPAP (Bi-level Positive Airway Pressure)

In bilevel positive airway pressure, IPAP refers to the inspiratory pressure and EPAP to the expiratory pressure. The difference between IPAP and EPAP represents the driving pressure that facilitates ventilation, which is why BiPAP can treat both hypoxemia and hypercarbia (BMC Pediatrics, 2010).

Typical Pediatric Starting Settings

• IPAP: 10 cm H₂O
• EPAP: 5 cm H₂O
• Based on PALOCC-2 Guidelines (Pediatric Respiratory and Critical Care Medicine, 2025), Goal tidal volume is between 6–8 mL/kg (avoid >10 mL/kg) 

Limits of Non-Invasive Support

Escalation toward intubation should be considered if the FiO₂ requirement remains greater than 70–80% after a reasonable period of time (Lancet Respiratory Medicine, 2019), if EPAP or PEEP exceeds 10 cm H₂O in bronchiolitis (Pediatric Critical Care Medicine, 2006), or if there is worsening fatigue, apnea, or changes in mental status. Neonates younger than six weeks have a lower tolerance for noninvasive ventilation and a higher risk of apnea and secondary pathology, so earlier escalation is recommended (expert opinion). 

Contraindications to NIV

Patients with the following should not use NIV, but rather require rapid intubation:

• Apnea
• Active vomiting or GI bleed
• Inability to protect airway
• Severe encephalopathy or post-sedation state
• Ongoing seizures

Interfaces Matter

Choosing the right interface is important, with the goal of achieving the best seal while minimizing leaks. Nasal masks are generally better tolerated but can be harder to seal, whereas oronasal or full-face masks offer a more secure seal but are less comfortable. RAM cannulas are commonly used in the NICU. Respiratory therapists are essential in this process, providing expertise in fitting, troubleshooting, and ongoing monitoring.

Blood Gases & Monitoring

Pulse oximetry is typically used to monitor oxygenation, while the physical exam is often sufficient to assess ventilation in bronchiolitis (AAP, 2014). Blood gases can be helpful when escalating noninvasive ventilation, evaluating the response to BiPAP, or when there is concern for impending intubation (BMC Pediatrics, 2010). As a general guideline, for every 10 mmHg increase in PaCO₂, the pH decreases by approximately 0.08 (Lancet Respiratory Medicine, 2019).

Timing & Reassessment

Patients on HFNC should be reassessed within 2–4 hours (NEJM, 2018), while those on CPAP/BiPAP require more frequent evaluations, relying primarily on the clinical exam rather than labs. Establishing clear, time-based goals helps prevent delayed intubation.

Outpatient & Parent Counseling

Teach parents to watch for:

• Fast breathing
• Retractions (show them where)
• Poor feeding
• Fewer wet diapers
• Worsening fatigue or color change
  

Demonstrate:

• Nasal suctioning (bulb or saline)
• How to roughly count respiratory rate

Health Disparities & Respiratory Disease

Children in underserved areas experience more severe bronchiolitis, higher rates of ICU admission, and increased mortality, which is associated with lower Childhood Opportunity Index scores. While prematurity increases risk, it does not fully account for these disparities (AAP, 2016).

Links

Open Pediatrics Ventilator Simulator is an interactive learning tool for understanding ventilator mechanics and settings (designed for invasive ventilation but excellent for foundational learning).

Goal

Non-invasive respiratory support is most effective when used intentionally and early, with a clear understanding of what physiologic problem you’re treating, close objective monitoring, and a well-defined plan to escalate if appropriate—because the goal is to support the child before they exhaust their reserve.

Listeners will explain the basic pathophysiology, diagnosis, and management of anaphylaxis to improve both inpatient emergent care and outpatient counseling. 

Learning Objectives

After listening to this episode listeners will…  

1. Differentiate respiratory distress from acute respiratory failure and apply clinical and physiologic criteria to pediatric patients.
2. Select an appropriate non-invasive respiratory support modality (HFNC, CPAP, or BiPAP) based on whether hypoxemia, hypercarbia, or both are present.
3. Initiate and titrate non-invasive respiratory support (HFNC, CPAP, and BiPAP) using weight-based flow rates, FiO₂ goals, starting pressures, and tidal volume targets, and identify objective indicators of treatment success, failure, and need for escalation.
4. Recognize early indicators of non-invasive support failure and determine when escalation to intubation is warranted.
5. Incorporate bedside exam findings, scoring tools, and interprofessional collaboration (especially with respiratory therapists) to guide ongoing respiratory management.
6. Counsel caregivers on outpatient warning signs of respiratory distress, including feeding changes, urine output, work of breathing, and color changes, and demonstrate practical home interventions such as nasal suctioning and estimating respiratory rate.

Disclosures

Dr. Michelle Perez reports no relevant financial disclosures. The Cribsiders report no relevant financial disclosures. 

Citation

Patel P, Perez M, Chisholm J, Berk J, Chiu C, Masur S. “#169: A Breath of Fresh Air: Non-invasive Respiratory Support”. The Cribsiders Pediatric Podcast. https:/www.thecribsiders.com/ February 25, 2026.