What are the normal resting vital sign ranges (heart rate, respiratory rate, blood pressure, temperature, pulse oximetry) for children at each developmental age group?

Normal Pediatric Vital Signs by Age Group

Use age-specific centile charts rather than fixed PALS thresholds for vital sign interpretation, as empirically derived values from large pediatric populations show that PALS criteria classify up to 75% of children as having "abnormal" vital signs when most are actually healthy. 1, 2

Heart Rate (beats per minute)

Neonates and Infants

• Birth to 1 month: Median 127-145 bpm (peaks at ~145 bpm around 1 month of age), with normal range approximately 93-182 bpm 3, 1
• 1-3 months: Median ~150 bpm, with normal range 121-179 bpm 3, 1
• 3-12 months: Progressive decline from median 150 bpm to approximately 130 bpm by 12 months 1

Children and Adolescents

• 1-2 years: Median 113 bpm, with steepest decline occurring during this period 1
• 2-5 years: Median continues gradual decline from 113 bpm toward 100 bpm 1
• School age (6-12 years): Median 80-100 bpm with continued age-related decline 4, 1
• Adolescents (13-18 years): Median approaches adult values of 60-90 bpm 1

Critical consideration: The 95th percentile for heart rate in real-world emergency department populations is consistently higher than PALS guidelines suggest, meaning PALS thresholds may inappropriately flag normal children as tachycardic 4, 2

Respiratory Rate (breaths per minute)

Neonates and Infants

• Birth: Median 44 breaths/min, with the steepest decline occurring in the first 2 years of life 1
• 1-12 months: Progressive decline from 44 to approximately 30 breaths/min 1

Children and Adolescents

• 2 years: Median 26 breaths/min, representing a dramatic decrease from birth 1
• 2-5 years: Median 24-26 breaths/min with gradual continued decline 1
• School age (6-12 years): Median 20-24 breaths/min 1
• Adolescents (13-18 years): Median approaches adult values of 12-20 breaths/min 1

Critical pitfall: Current PALS respiratory rate thresholds frequently exceed the 99th centile or fall below the 1st centile when compared to evidence-based centile charts, leading to misclassification 1

Blood Pressure (mmHg)

Measurement Requirements

• Proper cuff sizing is mandatory: Bladder width must be 40% of mid-arm circumference and cover 80-100% of arm circumference 5, 6
• Positioning: Child seated quietly with right arm at heart level on solid surface 5, 6
• Method: Auscultation remains the preferred diagnostic method 6

Age-Specific Values (50th percentile at 50th height percentile)

6-year-old children:

• Systolic BP: 105 mmHg (5th percentile ~98, 95th percentile 111 mmHg) 5
• Diastolic BP: 67 mmHg (5th percentile ~62, 95th percentile 74 mmHg) 5

Neonates (0-30 days):

• Limited standardized data available; values vary significantly by gestational age and postnatal age 3
• Heart rate ranges 93-182 bpm are more clinically relevant than BP in this age group 3

Classification for Children <13 Years

• Normal BP: <90th percentile for age, sex, and height 5, 6
• Elevated BP: ≥90th percentile and <95th percentile 5, 6
• Hypertension: ≥95th percentile for age, sex, and height 5, 6
• Stage 2 Hypertension: ≥95th percentile + 12 mmHg 5

Classification for Adolescents ≥13 Years

• Normal BP: <120/80 mmHg 6
• Elevated BP: 120-129/<80 mmHg 6
• Stage 1 Hypertension: 130/80 to 139/89 mmHg 6
• Stage 2 Hypertension: ≥140/90 mmHg 6

Critical consideration: Ambulatory BP monitoring (ABPM) differs substantially from casual measurements and should use German Working Group on Pediatric Hypertension reference values, though these have limitations for non-white children and those <140 cm height 3

Temperature

Normal core temperature: 36.5-37.5°C (97.7-99.5°F) across all pediatric age groups, though measurement site affects values 4

Pulse Oximetry

Normal oxygen saturation: ≥95% in healthy children at sea level across all ages 4, 7

Key Clinical Algorithms

When to Obtain Complete Vital Signs

• All children ≥3 years: Annual screening at preventive care visits 5, 6
• High-risk children: More frequent screening for those with obesity, diabetes, heart disease, or kidney disease 5, 6
• Emergency department: Complete vital signs (temperature, heart rate, respiratory rate, blood pressure, oxygen saturation) documented in only 50.8% of encounters, with higher documentation rates in older children and higher acuity presentations 7

When to Confirm Hypertension

• Elevated readings require confirmation: Three separate occasions unless symptomatic 6
• ABPM indicated: For children with office BP in elevated category for ≥1 year, or to exclude white coat hypertension 6
• ABPM preferred over home monitoring: Especially in high-risk conditions like obesity, though home monitoring is acceptable alternative if ABPM unavailable 6

Interpreting Abnormal Vital Signs

• Use centile-based approach: Express results as z-scores or percentiles rather than dichotomizing as "normal" vs "abnormal" 4, 1, 2
• Context matters: 73% of children with complete vital signs documentation had abnormal values by PALS criteria, but empirically derived percentiles (10th-90th) better predict need for medical interventions 7, 2
• Symptomatic bradycardia: Presence of dizziness, syncope, exercise intolerance, or chest pain requires ECG and possible cardiology referral 8

Major pitfall: PALS vital sign thresholds were not evidence-based and classify an inappropriately high proportion of healthy children as abnormal; use age-specific centile charts instead for more accurate risk stratification 4, 1, 2