What are the normal vital signs for a child?

Normal Vital Signs in Children

Normal vital signs in children vary significantly by age, with heart rate and respiratory rate declining from infancy through adolescence, requiring age-specific reference ranges for accurate clinical assessment.

Heart Rate Parameters by Age

Neonates and Young Infants

• First week of life (1-7 days): 91-166 bpm, with a mean of 123-129 bpm 1, 2
• 7-30 days: 107-182 bpm, with a mean of 149 bpm 1, 2
• 1-3 months: 121-179 bpm, with a mean of 150 bpm 2
• Heart rate shows a small peak at approximately 1 month of age, increasing from 127 bpm at birth to a maximum of 145 bpm, before declining 3

Older Infants and Children

• By 2 years: Median heart rate decreases to approximately 113 bpm 3
• Heart rate continues to decline gradually through childhood and adolescence 3, 4

Critical Thresholds

• Heart rate <60 bpm with signs of poor perfusion requires immediate CPR and chest compressions, as cardiac arrest is imminent 5, 1, 2
• Heart rates below the lower normal limit (e.g., <107 bpm in infants 7-30 days) may indicate pathology including CNS abnormalities, hypothermia, increased intracranial pressure, meningitis, or hypothyroidism 1, 2
• Heart rates above the upper normal limit (e.g., >182 bpm in infants 7-30 days) may indicate fever, infection, anemia, pain, dehydration, hyperthyroidism, or myocarditis 1, 2

Respiratory Rate Parameters by Age

Infants

• At birth: Median of 44 breaths per minute 3
• By 2 years: Median decreases to 26 breaths per minute 3
• The steepest decline in respiratory rate occurs in infants under 2 years of age 3
• Awake respiratory rate is significantly higher than sleeping rate in young children, with awake median of 59.3 at birth versus sleeping median of 41.4 6

Older Children

• Respiratory rate continues to decline from early childhood through adolescence 3, 7
• By teenage years, respiratory rates approach adult values 7

Important Consideration for Respiratory Rate Assessment

• Sleep state significantly impacts respiratory rate in children under 3 years, with awake rates being substantially higher than sleeping rates 6
• Measurement method matters: respiratory rate obtained with a stethoscope is systematically higher (by 2.6 breaths/minute when awake, 1.8 breaths/minute when asleep) than observation alone 8

Blood Pressure Parameters

Age-Specific Considerations

• Blood pressure varies by gestational age and postnatal age in neonates 1
• Hypertension in children is defined as systolic or diastolic blood pressure at or above the 95th percentile for age, height, and sex 5
• Stage 1 hypertension: SBP or DBP from 95th to 99th percentile plus 5 mmHg 5
• Stage 2 hypertension: SBP or DBP >99th percentile plus 5 mmHg 5

Clinical Assessment

• Blood pressure should be measured after 5 minutes of rest, with the patient seated and right arm supported at heart level 5
• Hypotension with capillary refill >3 seconds indicates more severe shock than isolated tachycardia 1
• For children <12 years, Pediatric Advanced Life Support definitions fit best, but these underestimate hypotension in older children 5

Critical Clinical Pitfalls to Avoid

Normal Physiological Variations

• Do not misinterpret transient bradycardia during feeding, sleep, or defecation as pathological—these represent normal vagal tone increases 1, 2
• Newborn infants may transiently reach heart rates up to 230 bpm during periods of distress, which can be normal 2
• Using 2nd and 98th percentiles means 4% of normal children will have values outside these ranges 1, 2

Assessment Context

• Altered mental status, poor peripheral perfusion, or weak pulses warrant immediate evaluation regardless of specific vital sign values 1
• Clinical context and overall condition are more important than isolated measurements 2
• Measurement artifacts are common in neonatal monitoring and can lead to inaccurate readings, particularly with movement, hiccoughs, or electrical interference 2

When to Intervene

• Persistent tachycardia (>182 bpm in infants 7-30 days) or bradycardia (<107 bpm in same age group) requires investigation for underlying causes 1, 2
• Provide rescue breathing at 1 breath every 2-3 seconds (20-30 breaths per minute) if pulse is present but breathing is absent or inadequate 5

Key Differences from Published Guidelines

Current evidence shows that many existing reference ranges frequently exceed the 99th and 1st centiles or cross the median when compared to large observational studies 3, 4. The APLS reference ranges particularly require review for respiratory rate in infants and teenagers 7. Real-world ED data demonstrates that empirical 95th centiles for heart rate and respiratory rate are higher than previously published results and deviate from PALS guideline recommendations 4.