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Acceptable ranges for physiological variables

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  • See also

    Sepsis
    Bradycardia during sleep
    Recognition of the seriously unwell neonate and young infant
    Hypertension

    Key points

    1. The table below provides acceptable ranges for systolic BP, heart rate and respiratory rate for unwell children
    2. Patterns of change in physiological variables are as important, as the thresholds shown here

    Background

    • There are many publications giving normal or acceptable ranges for physiological variables in children
    • Published values are quite disparate and probably reflect differing populations and assessment methods

    Assessment

    • The pattern of change in variables is often more important than the value itself. For example, a heart rate that is steadily rising through the acceptable range should trigger attention
      • Repeated observations are essential
      • Look at previous measurements in the same child, earlier in the admission, or during prior admissions
      • Consider measurements in the clinical context of the child
    • These values are generally the 5th and 95th percentile values for each paediatric variable, rounded to more workable values and consistent with Australian paediatric hospital observation charts

    Acceptable ranges for physiological variables

    Age

    Approximate Weight (kg)

    Systolic BP (mmHg)

    Heart Rate (Beats/minute)

    Respiratory Rate (Breaths/minute)

    Term

    3.5

    60-95

    120-170

    25-60

    3 months

    6

    60-105

    115-170

    25-60

    6 months

    8

    75-105

    110-170

    20-55

    1 year

    10

    70-105

    105-150

    20-45

    2 years

    12

    70-105

    95-150

    20-40

    4 years

    15

    75-110

    80-150

    17-30

    6 years

    20

    80-115

    75-140

    16-30

    8 years

    25

    80-115

    70-130

    16-30

    10 years

    30

    85-120

    60-130

    15-25

    12 years

    40

    90-120

    65-120

    15-25

    14 years

    50

    90-125

    60-115

    14-25

    16 years

    60

    90-130

    60-115

    14-25

    17+ years

    65

    90-135

    60-115

    14-25

    For emergency advice and paediatric or neonatal ICU transfers, see Retrieval services

    Additional Resources

    Last updated July 2023

  • Reference List

    1. Bonafide CP et al. Development of Heart and Respiratory Rate Percentile Curves for Hospitalized Children. Pediatrics 2013;131(4): e1150–7.
    2. Dionne JM et al. Hypertension in infancy: diagnosis, management and outcome. Pediatr Nephrology 2012;17–32.
    3. Fanaroff JM, Fanaroff AA. Blood pressure disorders in the neonate: Hypotension and hypertension. Semin Fetal Neonatal Med. 2006;174–81.
    4. Flynn JT et al. Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents Pediatrics 2017 140(3) 1904 
    5. Gemelli M et al. Longitudinal study of blood pressure during the 1st year of life. Eur J Pediatr. 1990;318–9.
    6. Haque IK et al. Analysis of the evidence for the lower limit of systolic and mean arterial pressure in children. Pediatr Crit Care Med. 2007;8(2):138–44.
    7. Lurbe E et al. Management of high blood pressure in children and adolescents: recommendations of the European society of hypertension. J Hypertens. 2009;27(9):1719–42.
    8. Sepanski RJ et al. Pediatric Vital Sign Distribution Derived From a Multi-Centered Emergency Department Database. Front Pediatr. 2018;6, 
    9. Tibballs J et al. Reduction of paediatric in-patient cardiac arrest and death with a medical emergency team: Preliminary results. Arch Dis Child. 2005;90(11):1148–52.