Vital signs by age
Why a “normal” value in a child is always only the beginning of the question, never its end
The sixth part of the PED series closes the block devoted to examining the child and returns to the numbers that appeared throughout the previous parts — heart rate, respiratory rate, blood pressure. The aim is not to provide yet another table to memorise, but to show how to use these values correctly: not as isolated numbers compared with a single norm, but as part of a trend and the overall clinical picture.
Approximate values by age
| Age | Heart rate (/min) | Respiratory rate (/min) | Systolic BP — lower limit |
|---|---|---|---|
| Neonate (0–28 days) | 100–205 (awake) | 30–60 | < 60 mmHg |
| Infant (1–12 mo) | 100–190 | 30–53 | < 70 mmHg |
| Toddler (1–2 years) | 98–140 | 22–37 | < 70 + (2 × age) mmHg |
| Preschool (3–5 yrs) | 80–120 | 20–28 | < 70 + (2 × age) mmHg |
| School age (6–11 yrs) | 75–118 | 18–25 | < 70 + (2 × age) mmHg |
| Adolescent (12–15 yrs) | 60–100 | 12–20 | < 90 mmHg |
Factors that distort the values
Vital signs in children are sensitive to a number of factors not directly related to the severity of the illness — and it is precisely this sensitivity that is the reason for caution when interpreting a single measurement:
- Crying and agitation: can raise both heart rate and respiratory rate without any connection to the underlying illness.
- Fever: typically raises the heart rate by approximately 10 beats/min for each degree Celsius above normal — without necessarily being a sign of circulatory instability.
- Pain and fear: especially at first contact with a stranger in uniform, can distort both respiratory and heart rate upwards.
- Sleep: the heart rate during sleep may be physiologically lower than the values given for the awake state.
The trend matters more than the single value
Repeated measurement during the call allows the direction of change to be tracked — an accelerating or, conversely, paradoxically slowing heart rate in a previously tachycardic child may signal deterioration before a single value does. This principle follows directly from the topic of compensated and decompensated shock in PED-03: a borderline or even “normalising” heart rate value may, in the setting of an overall deteriorating clinical picture, be a warning sign rather than a favourable finding.
Practical implications for the paramedic
- Always interpret vital signs together with the PAT and the overall clinical picture, never in isolation.
- Record the circumstances of measurement (crying, fever, agitation) — this makes interpretation easier for you and for the next link in the chain of care.
- Repeat measurements and follow the trend — a single value within normal does not exclude a serious condition, especially in a child in the compensated stage of shock.
- Match the lower limit of systolic BP to the child’s age (formula 70 + 2×age for 1–10 years) and remember that hypotension is a late, not an early, sign.
- American Heart Association. Pediatric Advanced Life Support (PALS) Provider Manual — criteria for hypotension and norms of vital signs by age.
- Van de Voorde P, Turner NM, Djakow J, et al. European Resuscitation Council Guidelines 2021: Paediatric Life Support. Resuscitation. 2021.
- Fleming S, et al. Normal ranges of heart rate and respiratory rate in children from birth to 18 years: a systematic review of observational studies. The Lancet. 2011.