3.3 Oxygen Delivery & Basic Airway Support

Oxygen Delivery Devices at Exam Level

PALS expects you to choose an oxygen interface that matches the child's severity, tolerance, and need for higher inspired oxygen fraction (FiO2). Exact FiO2 delivered varies with fit, flow, and the child's inspiratory demand, so memorize the relative hierarchy and clinical use cases rather than false precision.

Device comparison

Choosing among devices (decision logic)

1. Is spontaneous effort adequate? If no → bag-mask (or advanced airway per protocol), not just a higher-flow passive device.
2. How severe is hypoxemia/distress? Mild → blow-by or cannula if tolerated. Moderate to severe with good effort → simple mask or NRB.
3. Will the child tolerate the interface? Agitation that worsens obstruction (for example some upper-airway cases) may favor calm positioning and blow-by initially while preparing definitive care—without withholding oxygen from a truly hypoxemic child.
4. Reassess after each change. SpO2, work of breathing, mentation, and heart rate tell you whether to de-escalate, hold, or move to assisted ventilation.

Nonrebreather masks only work as designed when the reservoir inflates and the mask fits. A floppy empty reservoir or a mask perched on the forehead is not "being on an NRB."

SpO2 Teaching Targets for the Acutely Ill Child

Pulse oximetry is a core monitoring tool in PALS. Hypoxemia is commonly taught as SpO2 below the mid-90s on appropriate measurement. For acutely ill children who need oxygen, a widely taught PALS-oriented target range is approximately 94–99%—enough to correct hypoxemia while avoiding a culture of leaving children on pure oxygen indefinitely when titration is safe.

How to use this on the exam without overclaiming

• Treat clear hypoxemia and respiratory distress/failure immediately; do not withhold oxygen while debating a single cutoff.
• When the child is stabilizing and continuous oximetry is reliable, titrate oxygen to maintain saturations in a normal high range (commonly taught around the mid-to-high 90s) rather than maximizing FiO2 without purpose.
• Special populations (for example certain congenital heart disease physiologies with mixing lesions) may have intentionally lower baseline SpO2 targets set by specialists—follow local/expert pathways; standard PALS general-illness teaching still starts with recognizing inadequate oxygen delivery.
• After cardiac arrest (post-ROSC), guidelines emphasize avoiding both hypoxia and hyperoxia with careful titration; post-arrest detail is covered in later chapters. For the initial rescue of the hypoxemic failing child, prioritize relief of hypoxemia first.

Limitations of SpO2

• Poor perfusion, motion, cold extremities, and carbon monoxide can make readings inaccurate.
• SpO2 does not measure ventilation (CO2). A child can have a reassuring SpO2 and still be in ventilatory failure.
• SpO2 does not measure work of breathing. Severe distress can coexist with acceptable saturation on oxygen.

Always interpret the number with the clinical exam: appearance, work of breathing, and circulation to the skin.

Bag-Mask Ventilation Technique

Bag-mask ventilation (BMV) is the most important psychomotor skill for pediatric respiratory failure and the foundation of CPR ventilation before an advanced airway.

Keys to effective BMV

1. Airway open: Correct head position; consider airway adjuncts when indicated.
2. Mask seal: Cover the nose and mouth with the mask; do not compress the eyes. The E-C clamp technique is preferred: thumb and index finger form a "C" on the mask, remaining fingers form an "E" under the mandible to lift the jaw into the mask.
3. Two-person technique when available: One rescuer seals and opens; the second squeezes the bag. Two-person BMV usually produces a better seal in children with difficult anatomy or facial trauma.
4. Volume: Squeeze only until visible chest rise. Excessive volume risks gastric inflation, regurgitation, and reduced venous return.
5. Rate: For the child with a pulse in respiratory failure, ventilate at an age-appropriate rate with adequate time for exhalation—do not hyperventilate. During CPR without an advanced airway, coordinate breaths with compressions using pediatric ratios (30:2 single rescuer; 15:2 two-rescuer for infants/children).
6. Oxygen: Use a bag with an oxygen reservoir and adequate oxygen inflow whenever possible so delivered oxygen concentration is high.
7. Troubleshoot failure to oxygenate/ventilate: Reposition airway, suction, check seal, consider obstruction, ensure oxygen is connected, and escalate adjuncts or advanced airway as trained/protocol allows. The mnemonic family "MOANS/LEMON" style difficulty predictors is less emphasized than simply fixing position, seal, and obstruction in PALS testing.

Gastric inflation awareness

Forceful, rapid breaths fill the stomach, elevate the diaphragm, and make ventilation harder. Smooth breaths over about one second with chest-rise-limited volume reduce this risk. If the abdomen becomes distended and ventilation worsens, be prepared for suction and, when appropriate and trained, decompression strategies per local protocol—while maintaining oxygenation.

OPA and NPA: Sizing, Use, and Contraindications

Basic airway adjuncts help keep the tongue and soft tissues from blocking the pharynx during bag-mask ventilation or spontaneous breathing with depressed consciousness.

Oropharyngeal airway (OPA)

• Indication: Unconscious patient without a gag reflex who needs a patent airway for ventilation.
• Contraindication: Conscious or semi-conscious patient with an intact gag reflex—insertion can cause vomiting and aspiration.
• Sizing: Measure from the corner of the mouth to the angle of the mandible (or to the earlobe, depending on teaching product—same anatomic span). Too short fails to hold the tongue; too long may obstruct the larynx or injure structures.
• Insertion (exam-level): In children, avoid traumatic techniques; depress the tongue and insert without scraping the palate. Confirm that ventilation improves and that lips/teeth are not injured.

Nasopharyngeal airway (NPA)

• Indication: Soft upper-airway obstruction from the tongue when the patient has a gag reflex or cannot tolerate an OPA; useful in semi-conscious patients and some spontaneous breathers needing a patent nasal passage for oxygen or suctioning.
• Contraindications / cautions: Known or suspected basilar skull fracture, significant midface trauma, or coagulopathy concerns—risk of intracranial misplacement or bleeding. Choose another strategy if these risks are present.
• Sizing: Tip of the nose (nares) to the earlobe or angle of the mandible. Diameter should fit without blanching the nares excessively.
• Insertion: Lubricate; insert gently along the floor of the nose with bevel technique per training; never force against resistance.

Positioning: sniffing vs neutral

A rolled towel under an infant's shoulders often improves neutral alignment by compensating for the large occiput. In older children, a small towel under the occiput may help achieve sniffing position. Reassess chest rise after every position change.

Clinical scenario (synthesis)

A 5-year-old is unresponsive after a prolonged seizure, with sonorous upper-airway sounds and SpO2 88% on a nonrebreather that keeps falling off. Effort is irregular. Immediate plan: open the airway into a sniffing position, suction if secretions are present, insert an appropriately sized OPA only if no gag reflex, and begin bag-mask ventilation with oxygen using E-C clamp technique until spontaneous effective breathing and mentation return or advanced care takes over. If the child were semi-conscious with a gag reflex and isolated soft-tissue obstruction, an NPA (absent facial/basilar trauma) would be the safer adjunct while you support oxygenation.

Mastering device selection, SpO2 interpretation limits, BMV quality, and adjunct rules completes the respiratory fundamentals triad: recognize distress vs failure (3.1), intervene without delay (3.2), and apply the right oxygen and airway tools (3.3).