The PALS (Pediatric Advanced Life Support) breathing assessment evaluates five core components: respiratory rate and pattern, respiratory effort, chest expansion and air movement, lung and airway sounds, and oxygen saturation by pulse oximetry. These five elements form the breathing portion of the systematic approach taught in every AHA PALS course, and together they help providers quickly determine whether a child’s breathing is adequate, deteriorating, or failing.
Respiratory Rate and Pattern
Respiratory rate is the starting point of the assessment. Normal rates vary significantly by age. A newborn may breathe 30 to 60 times per minute, while a teenager’s normal rate is closer to 12 to 20. What matters in PALS is not just whether the rate is fast or slow, but whether the pattern is regular or irregular. A child breathing too fast (tachypnea) is often compensating for a problem, whether it’s an airway obstruction, a lung issue, or a metabolic condition like diabetic ketoacidosis that drives the body to blow off carbon dioxide.
An abnormally slow rate (bradypnea) in a child is more alarming than a fast one. Children tend to increase their rate when they’re in trouble, so a dropping respiratory rate often signals exhaustion or a neurological problem. Irregular breathing patterns, such as cycles of deep breaths followed by pauses, can point to brain injury or other central nervous system issues rather than a primary lung problem.
Respiratory Effort (Work of Breathing)
This component looks at how hard the child is working to breathe. Increased effort is one of the earliest and most visible signs that something is wrong. The key indicators include:
- Nasal flaring: the nostrils widen with each breath as the child tries to pull in more air
- Retractions: visible sinking of the skin between the ribs, above the collarbones, or below the rib cage during inhalation
- Head bobbing: especially in infants, the head rocks forward with each breath as the child uses neck muscles to assist breathing
- Accessory muscle use: the neck and abdominal muscles engage to help move air, something that doesn’t happen during normal, relaxed breathing
- Seesaw breathing: the chest pulls in while the abdomen pushes out, or vice versa, indicating the diaphragm is doing nearly all the work against significant resistance
The presence and severity of these signs help distinguish respiratory distress from respiratory failure. A child in distress is working hard but still compensating. Their body is keeping up, even if it’s clearly struggling. Respiratory failure is the point where those compensatory mechanisms break down. Paradoxically, a child in failure may show less visible effort than one in distress, because they’re too exhausted or neurologically impaired to keep fighting. That reduction in effort without clinical improvement is a red flag, not a reassuring sign.
Chest Expansion and Air Movement
This component assesses tidal volume, the amount of air actually moving in and out of the lungs with each breath. Providers evaluate it by watching for symmetric chest rise and listening for the quality of air entry with a stethoscope. Both sides of the chest should expand equally. Unequal expansion suggests a problem on one side, such as a collapsed lung or a foreign body blocking one of the main airways.
Visual assessment of chest rise is a practical bedside tool, but it has real limitations. Research on infants receiving mask ventilation found that clinicians frequently underestimated the actual volume of air being delivered, and some couldn’t reliably assess chest movement at all from either a head or side view. This is why PALS treats chest expansion as one piece of a larger picture rather than a standalone finding. Diminished or absent chest rise, combined with other signs like poor effort or abnormal sounds, paints a much clearer picture than any single observation.
Lung and Airway Sounds
Abnormal sounds during breathing help localize where the problem is. The assessment considers both sounds you can hear without a stethoscope and those detected through auscultation (listening with a stethoscope over the chest).
Stridor, a high-pitched sound heard during inhalation, typically points to an upper airway obstruction. Croup, swelling near the vocal cords, or a foreign body lodged in the throat can all produce stridor. Wheezing, a musical sound heard most often during exhalation, suggests narrowing in the lower airways, as seen in asthma or bronchiolitis. Grunting, a short sound at the end of each breath, occurs when a child instinctively closes the vocal cords briefly to keep the small air sacs in the lungs from collapsing. It’s common in conditions affecting lung tissue itself, like pneumonia.
Absent or diminished breath sounds over part of the lung are just as important as abnormal noises. If air isn’t reaching a region of the lung, that silence tells the provider something is blocking flow or the lung tissue in that area isn’t functioning.
Oxygen Saturation by Pulse Oximetry
The final component is pulse oximetry, which measures the percentage of hemoglobin in the blood carrying oxygen (SpO2). It provides an objective number to pair with the physical findings from the other four components. In children with respiratory distress, supplemental oxygen is generally indicated when SpO2 drops to the 90 to 94% range. Healthy children at sea level typically maintain saturations above 95%.
Some evidence suggests that SpO2 thresholds as low as 88% may be safe in certain situations and could reduce the need for hospitalization, but in a PALS emergency setting, the goal is to keep oxygen levels at or above the recommended threshold. It’s worth noting that pulse oximetry has limitations. It can give falsely reassuring readings in carbon monoxide poisoning, and it becomes less accurate at very low saturations. Cold hands, poor circulation, or excessive movement can also interfere with the reading.
How the Five Components Work Together
No single finding from the breathing assessment tells the whole story. A fast respiratory rate with clear lung sounds and normal oxygen saturation may simply reflect a fever or anxiety. That same fast rate paired with retractions, wheezing, and an SpO2 of 91% points to a child in genuine respiratory distress who needs intervention.
PALS teaches providers to use all five components to classify the child’s respiratory problem into one of four categories: upper airway obstruction, lower airway obstruction, lung tissue disease, or disordered control of breathing. Upper airway problems tend to produce stridor and increased inspiratory effort. Lower airway problems produce wheezing and prolonged exhalation. Lung tissue disease leads to grunting, crackles on auscultation, and often a greater drop in oxygen saturation. Disordered control of breathing, caused by neurological injury, drug exposure, or metabolic emergencies, shows up as irregular patterns with effort that seems inappropriately low for how sick the child appears.
This classification matters because the treatments differ. A child with upper airway swelling needs a different approach than one whose small airways are constricted, even though both present with increased work of breathing. The five-component assessment gives providers the information to make that distinction quickly and act on it.