Synopsis
Measure paediatric observations accurately, compare them with current age-specific reference limits and interpret state, baseline and trend without missing compensated deterioration.
- Measure before interpreting: observe a settled child, count respiratory rate for a full minute in infants and use a correctly sized blood-pressure cuff and reliable saturation waveform.
- RCUK 2025 approximate respiratory-rate ranges are 25–60/min at 1 month, 20–50 at 1 year, 18–40 at 2 years, 17–30 at 5 years, 14–25 at 10 years and 12–20 at 18 years.
- RCUK 2025 approximate heart-rate ranges are 110–180/min at 1 month, 100–170 at 1 year, 90–160 at 2 years, 70–140 at 5 years, 60–120 at 10 years and 60–100 at 18 years.
- Median systolic pressure rises with age: approximately 75 mmHg at 1 month, 95 at 1 year, 98 at 2 years, 100 at 5 years, 110 at 10 years and 120 at 18 years.
- The RCUK fifth-centile systolic values are approximately 50 mmHg at 1 month, 70 at 1 year, 73 at 2 years, 75 at 5 years, 80 at 10 years and 90 at 18 years.
- Use intermediate values between table ages and the National PEWS chart assigned to the child's age band; physiology changes continuously rather than on birthdays.
- Crying, pain, fever, exercise and anxiety can raise pulse and respiratory rate, but persistent abnormality after settling or analgesia still needs explanation.
- A normal blood pressure does not exclude compensated shock; interpret pulses, refill, skin temperature, mental state and urine together.
- Capillary refill longer than 3 seconds is abnormal in NICE fever assessment when measured centrally under appropriate conditions, but normal refill cannot exclude shock.
- Healthy children at sea level generally have saturation 95% or higher, but check signal quality and use the prescribed baseline target in congenital cyanotic heart or chronic respiratory disease.
- Urine output is a perfusion trend: commonly seek about 2 mL/kg/hour in infants, 1 mL/kg/hour in children and 0.5 mL/kg/hour in adolescents, interpreted with renal and fluid context.
- Trend and clinical pattern outweigh an isolated borderline reading; document state, oxygen, device, site and interventions with each set.
Key red flags
A falling respiratory rate with reduced effort, poor air entry or drowsiness indicates exhaustion rather than recovery.
Bradycardia with poor perfusion or hypoxia is a peri-arrest sign; RCUK treats a rate below 60/min with poor perfusion as cardiac arrest physiology.
Hypotension is a late sign of paediatric shock and must not be awaited when pulses, refill, skin, urine or consciousness are abnormal.
Oxygen saturation below 90% in air represents severe hypoxaemia in RCUK respiratory-failure assessment, while individual targets apply in cyanotic or chronic disease.
Temperature 38°C or higher below 3 months, or 39°C or higher at 3–6 months, carries age-specific NICE fever risk and needs urgent assessment.
Investigation priorities
Detect early respiratory or metabolic stress and later fatigue.
Assess cardiovascular compensation and possible arrhythmia.
Management branches
A child requires a baseline or repeat observation set.
- Settle and observe the child, select age-appropriate probe and cuff and record oxygen and behavioural state.
- Measure respiratory rate, pulse, saturation, temperature, perfusion and indicated blood pressure and consciousness accurately.
- Plot on the correct PEWS chart and compare with RCUK age ranges, baseline and previous values.