These are the paediatric reference ranges used throughout the case decks and question sets on Pediatric Case Review. Every deck links here, and inside a deck the same tables open in a panel with the values quoted by that particular question highlighted.
They are typical values for teaching and exam preparation. A real laboratory quotes its own ranges, and several of these move with age — always read the local range printed on the report.
Typical paediatric values. A real laboratory quotes its own ranges, and several of these move with age.
Vital signs by age
| Age | Heart rate | Respiratory rate | Systolic BP — hypotension below |
|---|
| Term newborn | 110–160 | 30–40 | 60 mmHg |
| 1–12 months | 110–160 | 30–40 | 70 mmHg |
| 1–2 years | 100–150 | 25–35 | 70 + (2 × age) mmHg |
| 2–5 years | 95–140 | 25–30 | 70 + (2 × age) mmHg |
| 5–12 years | 80–120 | 20–25 | 70 + (2 × age) mmHg |
| Over 12 years | 60–100 | 15–20 | 90 mmHg |
Other bedside measures
| Measure | Reference | Note |
|---|
| Temperature | 36.5–37.5 °C | 38.0 or above is fever |
| Oxygen saturation | 94–100 percent in air | under 92 in air needs oxygen and admission |
| Capillary refill | under 2 seconds | 3 seconds or more suggests shock |
| Heart rate | see the table above | age dependent |
| Respiratory rate | see the table above | age dependent |
| Blood pressure | see the table above | age dependent |
Arterial blood gas
| Measure | Reference | Note |
|---|
| pH | 7.35–7.45 | |
| PaCO2 | 35–45 mmHg (4.7–6.0 kPa) | the respiratory term |
| PaO2 | 80–100 mmHg (10.6–13.3 kPa) | breathing room air |
| Bicarbonate | 22–26 mmol/L | the metabolic term |
| Base excess | −2 to +2 mmol/L | |
| Lactate | under 2 mmol/L | over 4 marks shock |
| A–a gradient | under 10–15 mmHg in air | a normal gradient means the lungs are not the problem |
Haematology
| Measure | Reference | Age note |
|---|
| Haemoglobin | see age note | newborn 14–22 g/dL; physiological nadir 9.5–13.5 at 6–9 weeks; 6 months to 6 years 10.5–14; 6–12 years 11.5–15.5 |
| White cells | see age note | newborn 9–30 ×109/L; 1 year 6–18; 4–10 years 4–13.5; adolescent 4.5–11 |
| Neutrophils | neutropenia under 1.5 ×109/L, severe under 0.5 | |
| Platelets | 150–450 ×109/L | |
| MCV | lower limit roughly 70 + age in years (fL) | to about 12 years |
| ESR | under 10–20 mm/h | |
| CRP | under 5–10 mg/L | laboratory dependent |
Electrolytes and renal
| Measure | Reference | Note |
|---|
| Sodium | 135–145 mmol/L | |
| Potassium | 3.5–5.0 mmol/L | up to 6.0 in the newborn |
| Chloride | 98–107 mmol/L | |
| Bicarbonate | 22–26 mmol/L | same value as on the gas |
| Urea | 2.5–6.5 mmol/L (7–18 mg/dL) | |
| Creatinine | infant 15–35, child 25–60, adolescent 50–90 µmol/L | rises with muscle mass, so an adult range over-reads a child |
| Glucose | 3.5–5.5 mmol/L (63–99 mg/dL) | newborn above 2.6 mmol/L |
| Urine sodium / chloride | under 20 mmol/L means the loss is not renal | a high urine chloride points to the kidney or a diuretic |
Liver, bone and metabolic
| Measure | Reference | Note |
|---|
| ALT / AST | 10–40 / 10–45 U/L | |
| GGT | 5–35 U/L | up to 200 in the first months of life |
| Alkaline phosphatase | child 100–400 U/L, higher in the growth spurt | an adult range makes normal childhood bone turnover look like disease |
| Bilirubin (total) | under 17 µmol/L (1 mg/dL) beyond the newborn period | |
| Conjugated bilirubin | under 17 µmol/L, or under 20 percent of total | above this is always pathological |
| Albumin | 35–50 g/L | |
| Ammonia | newborn under 110, child under 50 µmol/L | |
| Calcium / magnesium / phosphate | 2.2–2.7 / 0.7–1.0 / 1.2–2.0 mmol/L | phosphate runs higher in infancy, to about 2.6 |
| Lipase or amylase | three times the upper limit defines pancreatitis | |
| Sweat chloride | under 30 normal, 30–59 intermediate, 60 or more diagnostic | |
Cerebrospinal fluid
| Measure | Newborn | Child |
|---|
| White cells | 0–20 /mm3 | 0–5 /mm3 |
| Protein | 0.4–1.2 g/L | 0.15–0.45 g/L |
| Glucose | at least 60 percent of the blood glucose | at least 60 percent of the blood glucose |
| Bacterial pattern | hundreds to thousands of neutrophils, high protein, low glucose | same |