Chapter 27

Blood Chemistries and Body Fluids

Branden Engorn, MD,  and Jamie Flerlage, MD
Determining normal reference ranges of laboratory studies in pediatric patients poses some major challenges. Available literature is often limited because of the small sample sizes of patients in many studies that have been used to derive these suggested normal ranges. Please use great caution and be aware of this limitation when interpreting pediatric laboratory studies.
The values that follow are compiled from both published literature and the Johns Hopkins Hospital Department of Pathology. Normal values vary with the analytic method used. Consult your laboratory for its analytic method and range of normal values and for less commonly used parameters, which are beyond the scope of this text. Additional normal laboratory values may be found in Chapters 10, 14, and 15.
A special thanks to Lori Sokoll, PhD, and Athena Kantartzis, PhD, for their guidance in preparing this chapter.

I. Reference Values (Table 27-1)

TABLE 27-1

Reference Values

Conventional UnitsSI Units
ALANINE AMINOTRANSFERASE (ALT)1,2
(Major sources: Liver, skeletal muscle, and myocardium)
Infant <12 mo13–45 U/L13–45 U/L
1–3 yr5–45 U/L5–45 U/L
4–6 yr10–25 U/L10–25 U/L
7–9 yr10–35 U/L10–35 U/L
10–11 yr
Female10–30 U/L10–30 U/L
Male10–35 U/L10–35 U/L
12–13 yr
Female10–30 U/L10–30 U/L
Male10–55 U/L10–55 U/L
14–15 yr
Female5–30 U/L5–30 U/L
Male10–45 U/L10–45 U/L
>16 yr
Female5–35 U/L5–35 U/L
Male10–40 U/L10–40 U/L
Table Continued

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Conventional UnitsSI Units
ALBUMIN
(See Proteins)
ALDOLASE3
(Major sources: Skeletal muscle and myocardium)
10–24 mo3.4–11.8 U/L3.4–11.8 U/L
2–16 yr1.2–8.8 U/L1.2–8.8 U/L
Adult1.7–4.9 U/L1.7–4.9 U/L
ALKALINE PHOSPHATASE4
(Major sources: Liver, bone, intestinal mucosa, placenta, and kidney)
Infant150–420 U/L150–420 U/L
2–10 yr100–320 U/L100–320 U/L
Adolescent male100–390 U/L100–390 U/L
Adolescent female100–320 U/L100–320 U/L
Adult30–120 U/L30–120 U/L
AMMONIA2
(Heparinized venous specimen on ice analyzed within 30 min)
Newborn90–150 mcg/dL64–107 µmol/L
0–2 wk79–129 mcg/dL56–92 µmol/L
Infant/child29–70 mcg/dL21–50 µmol/L
Adult15–45 mcg/dL11–32 µmol/L
AMYLASE15
(Major sources: Pancreas, salivary glands, and ovaries)
0–14 days3–10 U/L3–10 U/L
15 days–13 wk2–22 U/L2–22 U/L
13 wk–1 yr3–50 U/L3–50 U/L
>1 yr25–101 U/L25–101 U/L
ANTINUCLEAR ANTIBODY (ANA)2IMMUNOFLUORESCENCE ASSAY (IFA)
Negative<1:40
Patterns with clinical correlation:
Centromere: CREST∗
Nucleolar: Scleroderma
Homogeneous: Systemic lupus erythematosus (SLE)
ANTISTREPTOLYSIN O TITER5
(Fourfold rise in paired serial specimens is significant.)
NewbornSimilar to mother’s value
6–24 mo≤50 Todd units/mL
2–4 yr≤160 Todd units/mL
≥5 yr≤330 Todd units/mL
Table Continued

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Conventional UnitsSI Units
ASPARTATE AMINOTRANSFERASE (AST)2
(Major sources: Liver, skeletal muscle, kidney, myocardium, and erythrocytes)
0–10 days47–150 U/L47–150 U/L
10 days–24 mo9–80 U/L9–80 U/L
>24 mo
Female13–35 U/L13–35 U/L
Male15–40 U/L15–40 U/L
BICARBONATE2,4
Newborn17–24 mEq/L17–24 mmol/L
Infant19–24 mEq/L19–24 mmol/L
2 mo–2 yr16–24 mEq/L16–24 mmol/L
>2 yr22–26 mEq/L22–26 mmol/L
BILIRUBIN (TOTAL)4,6
(Please see Chapter 18 for more complete information about neonatal hyperbilirubinemia and acceptable bilirubin values.)
Cord:
Term and preterm<2 mg/dL<34 µmol/L
0–1 days:
Term and preterm<8 mg/dL<137 µmol/L
1–2 days:
Preterm<12 mg/dL<205 µmol/L
Term<11.5 mg/dL<197 µmol/L
3–5 days:
Preterm<16 mg/dL<274 µmol/L
Term<12 mg/dL<205 µmol/L
Older infant:
Preterm<2 mg/dL<34 µmol/L
Term<1.2 mg/dL<21 µmol/L
Adult<1.5 mg/dL<20.5 µmol/L
BILIRUBIN (CONJUGATED)2–4
Neonate<0.6 mg/dL<10 µmol/L
Infants/children<0.2 mg/dL<3.4 µmol/L

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BLOOD GAS, ARTERIAL (BREATHING ROOM AIR)2
pHPaO2 (mmHg)PaCO2 (mmHg)HCO3− (mEq/L)
Cord blood7.28 ± 0.0518.0 ± 6.249.2 ± 8.414–22
Newborn (birth)7.11–7.368–2427–4013–22
5–10 min7.09–7.3033–7527–4013–22
30 min7.21–7.3831–8527–4013–22
60 min7.26–7.4955–8027–4013–22
1 day7.29–7.4554–9527–4013–22
Child/adult7.35–7.4583–10832–4820–28
Table Continued

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BLOOD GAS, ARTERIAL (BREATHING ROOM AIR)2
pHPaO2 (mmHg)PaCO2 (mmHg)HCO3− (mEq/L)
NOTE: Venous blood gases can be used to assess acid-base status, not oxygenation. PCO2 averages 6–8 mmHg higher than PaCO2, and pH is slightly lower. Peripheral venous samples are strongly affected by the local circulatory and metabolic environment. Capillary blood gases correlate best with arterial pH and moderately well with PaCO2.

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Conventional UnitsSI Units
C-REACTIVE PROTEIN40–0.5 mg/dL
CALCIUM (TOTAL)2
Premature neonate6.2–11 mg/dL1.55–2.75 mmol/L
0–10 days7.6–10.4 mg/dL1.9–2.6 mmol/L
10 days–24 mo9–11 mg/dL2.25–2.75 mmol/L
24 mo–12 yr8.8–10.8 mg/dL2.2–2.7 mmol/L
12–18 yr8.4–10.2 mg/dL2.1–2.55 mmol/L
CALCIUM (IONIZED)3
0–1 mo3.9–6.0 mg/dL1.0–1.5 mmol/L
1–6 mo3.7–5.9 mg/dL0.95–1.5 mmol/L
1–18 yr4.9–5.5 mg/dL1.22–1.37 mmol/L
Adult4.75–5.3 mg/dL1.18–1.32 mmol/L
CARBON DIOXIDE (CO2 CONTENT)2
(See Blood Gas, Arterial)
CARBON MONOXIDE (CARBOXYHEMOGLOBIN)
Nonsmoker0.5%–1.5% of total hemoglobin
Smoker4%–9% of total hemoglobin
Toxic20%–50% of total hemoglobin
Lethal>50% of total hemoglobin
Conventional UnitsSI Units
CHLORIDE (SERUM)3
0–6 mo97–108 mEq/L97–108 mmol/L
6–12 mo97–106 mEq/L97–106 mmol/L
Child/adult97–107 mEq/L97–107 mmol/L
CHOLESTEROL
(See Lipids)
CREATINE KINASE (CREATINE PHOSPHOKINASE)2
(Major sources: Myocardium, skeletal muscle, smooth muscle, and brain)
Newborn145–1,578 U/L145–1578 U/L
>6 wk–adult male20–200 U/L20–200 U/L
>6 wk–adult female20–180 U/L20–180 U/L
Table Continued

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Conventional UnitsSI Units
CREATININE (SERUM)2 (Enzymatic)
Cord0.6–1.2 mg/dL53–106 µmol/L
Newborn0.3–1.0 mg/dL27–88 µmol/L
Infant0.2–0.4 mg/dL18–35 µmol/L
Child0.3–0.7 mg/dL27–62 µmol/L
Adolescent0.5–1.0 mg/dL44–88 µmol/L
Adult male0.9–1.3 mg/dL80–115 µmol/L
Adult female0.6–1.1 mg/dL53–97 µmol/L
ERYTHROCYTE SEDIMENTATION RATE (ESR)2
Child0–10 mm/hr
Adult male0–15 mm/hr
Adult female0–20 mm/hr
FERRITIN2
Newborn25–200 ng/mL56–450 pmol/L
1 mo200–600 ng/mL450–1350 pmol/L
2–5 mo50–200 ng/mL112–450 pmol/L
6 mo–15 yr7–140 ng/mL16–315 pmol/L
Adult male20–250 ng/mL45–562 pmol/L
Adult female10–120 ng/mL22–270 pmol/L
FIBRINOGEN
(See Chapter 14)
FOLATE (SERUM)3
Newborn16–72 ng/mL16–72 nmol/L
Child4–20 ng/mL4–20 nmol/L
Adult10–63 ng/mL10–63 nmol/L
FOLATE (RBC)2
Newborn150–200 ng/mL340–453 nmol/L
Infant74–995 ng/mL168–2254 nmol/L
2–16 yr>160 ng/mL>362 nmol/L
>16 yr140–628 ng/mL317–1422 nmol/L
GALACTOSE2
Newborn0–20 mg/dL0–1.11 mmol/L
Older child<5 mg/dL<0.28 mmol/L
GAMMA-GLUTAMYL TRANSFERASE (GGT)2,5
(Major sources: Liver [biliary tree] and kidney)
Cord37–193 U/L37–193 U/L
0–1 mo13–147 U/L13–147 U/L
1–2 mo12–123 U/L12–123 U/L
2–4 mo8–90 U/L8–90 U/L
4 mo–10 yr5–32 U/L5–32 U/L
Table Continued

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Conventional UnitsSI Units
10–15 yr5–24 U/L5–24 U/L
Adult male11–49 U/L11–49 U/L
Adult female7–32 U/L7–32 U/L
GLUCOSE (SERUM)2,5
Preterm20–60 mg/dL1.1–3.3 mmol/L
Newborn, <1 day40–60 mg/dL2.2–3.3 mmol/L
Newborn, >1 day50–90 mg/dL2.8–5.0 mmol/L
Child60–100 mg/dL3.3–5.5 mmol/L
>16 yr70–105 mg/dL3.9–5.8 mmol/L
HAPTOGLOBIN2
Newborn5–48 mg/dL50–480 mg/L
>30 days26–185 mg/dL260–1850 mg/L
HEMOGLOBIN A1C7
Normal4.5%–5.6%
At risk for diabetes5.7%–6.4%
Diabetes mellitus≥6.5%
HEMOGLOBIN F, % TOTAL HEMOGLOBIN (MEAN [SD])2
1 day77.0 (7.3)
5 days76.8 (5.8)
3 wk70.0 (7.3)
6–9 wk52.9 (11)
3–4 mo23.2 (16)
6 mo4.7 (2.2)
8–11 mo1.6 (1.0)
Adult<2.0
IRON2
Newborn100–250 mcg/dL17.9–44.8 µmol/L
Infant40–100 mcg/dL7.2–17.9 µmol/L
Child50–120 mcg/dL9.0–21.5 µmol/L
Adult male65–175 mcg/dL11.6–31.3 µmol/L
Adult female50–170 mcg/dL9.0–30.4 µmol/L
LACTATE2,3
Capillary blood:
0–90 days9–32 mg/dL1.1–3.5 mmol/L
3–24 mo9–30 mg/dL1.0–3.3 mmol/L
2–18 yr9–22 mg/dL1.0–2.4 mmol/L
Venous4.5–19.8 mg/dL0.5–2.2 mmol/L
Arterial4.5–14.4 mg/dL0.5–1.6 mmol/L
LACTATE DEHYDROGENASE (AT 37°C)2
(Major sources: Myocardium, liver, skeletal muscle, erythrocytes, platelets, and lymph nodes)
0–4 days290–775 U/L290–775 U/L
4–10 days545–2000 U/L545–2000 U/L
Table Continued

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Conventional UnitsSI Units
10 days–24 mo180–430 U/L180–430 U/L
24 mo–12 yr110–295 U/L110–295 U/L
>12 yr100–190 U/L100–190 U/L
LEAD2
Child<10 mcg/dL<0.48 µmol/L
LIPASE3
0–30 days6–55 U/L6–55 U/L
1–6 mo4–29 U/L4–29 U/L
6–12 mo4–23 U/L4–23 U/L
>1 yr3–32 U/L3–32 U/L

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Cholesterol (mg/dL)LDL (mg/dL)HDL (mg/dL)
DesirableBorderlineHighOptimalNear/Above optimalBorderlineHighDesirable
LIPIDS8,9
Child/adolescent<170170–199>200<110110–129>130>35
Adult<200200–239<240<100100–129130–159>16040–60

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Conventional UnitsSI Units
MAGNESIUM21.6–2.4 mg/dL0.63–1.05 mmol/L
METHEMOGLOBIN20.78% (±0.37%) of total hemoglobin
OSMOLALITY2275–295 mOsm/kg (neonates as low as 266)275–295 mmol/kg
PHENYLALANINE2
Preterm2.0–7.5 mg/dL121–454 µmol/L
Newborn1.2–3.4 mg/dL73–206 µmol/L
Adult0.8–1.8 mg/dL48–109 µmol/L
PHOSPHORUS2
0–9 days4.5–9.0 mg/dL1.45–2.91 mmol/L
10 days–24 mo4–6.5 mg/dL1.29–2.10 mmol/L
3–9 yr3.2–5.8 mg/dL1.03–1.87 mmol/L
10–15 yr3.3–5.4 mg/dL1.07–1.74 mmol/L
>15 yr2.4–4.4 mg/dL0.78–1.42 mmol/L
PORCELAIN109.0–24.11 mg/dL9.0–28.13 mmol/L
POTASSIUM2
Preterm3.0–6.0 mEq/L3.0–6.0 mmol/L
Newborn3.7–5.9 mEq/L3.7–5.9 mmol/L
Infant4.1–5.3 mEq/L4.1–5.3 mmol/L
Child3.4–4.7 mEq/L3.4–4.7 mmol/L
Adult3.5–5.1 mEq/L3.5–5.1 mmol/L
Table Continued

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Conventional UnitsSI Units
PREALBUMIN3
Newborn7–39 mg/dL
1–6 mo8–34 mg/dL
6 mo–4 yr12–36 mg/dL
4–6 yr12–30 mg/dL
6–19 yr12–42 mg/dL

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PROTEIN ELECTROPHORESIS (g/dL)2
AgeTotal ProteinAlbuminα-1α-2βγ
Cord4.8–8.0
Premature3.6–6.0
Newborn4.6–7.0
0–15 day4.4–7.63.0–3.90.1–0.30.3–0.60.4–0.60.7–1.4
15 day–1 yr5.1–7.32.2–4.80.1–0.30.5–0.90.5–0.90.5–1.3
1–2 yr5.6–7.53.6–5.20.1–0.40.5–1.20.5–1.10.5–1.7
3–16 yr6.0–8.03.6–5.20.1–0.40.5–1.20.5–1.10.5–1.7
≥16 yr6.0–8.33.9–5.10.2–0.40.4–0.80.5–1.00.6–1.2

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Conventional UnitsSI Units
PYRUVATE30.7–1.32 mg/dL0.08–0.15 mmol/L
RHEUMATOID FACTOR2<30 U/mL
SODIUM1
<1 yr130–145 mEq/L130–145 mmol/L
>1 yr135–147 mEq/L135–147 mmol/L
TOTAL IRON-BINDING CAPACITY (TIBC)2
Infant100–400 mcg/dL17.9–71.6 µmol/L
Adult250–425 mcg/dL44.8–76.1 µmol/L
TOTAL PROTEIN
(See Proteins)
TRANSAMINASE (SGOT)
(See Aspartate aminotransferase [AST])
TRANSAMINASE (SGPT)
(See Alanine aminotransferase [ALT])
TRANSFERRIN2
Newborn130–275 mg/dL1.30–2.75 g/L
3 mo–16 yr203–360 mg/dL2.03–3.6 g/L
Adult215–380 mg/dL2.15–3.8 g/L

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TOTAL TRIGLYCERIDE3
Conventional Units (mg/dL)SI Units (mmol/L)
MaleFemaleMaleFemale
0–7 days21–18228–1660.24–2.060.32–1.88
8–30 days30–18430–1650.34–2.080.34–1.86
31–90 days40–17535–2820.45–1.980.4–3.19
91–180 days45–29150–3550.51–3.290.57–4.01
181–365 days45–50136–4310.51–5.660.41–4.87
1–3 yr27–12527–1250.31–1.410.31–1.41
4–6 yr32–11632–1160.36–1.310.36–1.31
7–9 yr28–12928–1290.32–1.460.32–1.46
10–19 yr24–14537–1400.27–1.640.42–1.58

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Conventional UnitsSI Units
TROPONIN-I3
0–30 days<4.8 mcg/L
31–90 days<0.4 mcg/L
3–6 mo<0.3 mcg/L
7–12 mo<0.2 mcg/L
1–18 yr<0.1 mcg/L
UREA NITROGEN1,2
Premature (<1 wk)3–25 mg/dL1.1–8.9 mmol/L
Newborn2–19 mg/dL0.7–6.7 mmol/L
Infant/child5–18 mg/dL1.8–6.4 mmol/L
Adult6–20 mg/dL2.1–7.1 mmol/L
URIC ACID3,5
0–30 days1.0–4.6 mg/dL0.059–0.271 mmol/L
1–12 mo1.1–5.6 mg/dL0.065–0.33 mmol/L
1–5 yr1.7–5.8 mg/dL0.1–0.35 mmol/L
6–11 yr2.2–6.6 mg/dL0.13–0.39 mmol/L
Male 12–19 yr3.0–7.7 mg/dL0.18–0.46 mmol/L
Female 12–19 yr2.7–5.7 mg/dL0.16–0.34 mmol/L
VITAMIN A (RETINOL)2,3
Preterm13–46 mcg/dL0.46–1.61 µmol/L
Full term18–50 mcg/dL0.63–1.75 µmol/L
1–6 yr20–43 mcg/dL0.7–1.5 µmol/L
7–12 yr20–49 mcg/dL0.9–1.7 µmol/L
13–19 yr26–72 mcg/dL0.9–2.5 µmol/L
VITAMIN B1 (THIAMINE)24.5–10.3 mcg/dL106–242 µmol/L
VITAMIN B2 (RIBOFLAVIN)4–24 mcg/dL106–638 nmol/L
VITAMIN B12 (COBALAMIN)2
Newborn160–1300 pg/mL118–959 pmol/L
Child/adult200–835 pg/mL148–616 pmol/L
Table Continued

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Conventional UnitsSI Units
VITAMIN C (ASCORBIC ACID)20.4–2.0 mg/dL23–114 µmol/L
VITAMIN D3 (1,25-DIHYDROXY-VITAMIN D)216–65 pg/mL42–169 pmol/L
VITAMIN E1,2,3
Preterm0.5–3.5 mg/L1–8 µmol/L
Full term1.0–3.5 mg/L2–8 µmol/L
1–12 yr3.0–9.0 mg/L7–21 µmol/L
13–19 yr6.0–10.0 mg/L14–23 µmol/L
ZINC270–120 mcg/dL10.7–18.4 mmol/L

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∗ CREST: Calcinosis, Raynaud syndrome, Esophageal dysmotility, Sclerodactyly, Telangiectasia.

II. Evaluation of Body Fluids

B. Evaluation of Cerebrospinal Fluid (Table 27-3)
C. Evaluation of Synovial Fluid (Table 27-4)

TABLE 27-3

Evaluation of Cerebrospinal Fluid

Age4,11WBC Count/µL (median)95th Percentile
0–28 days0–12∗(3)19
29–56 days0–6∗ (2)9
Child0–7

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Conventional UnitsSI Units
GLUCOSE4,12
Preterm24–63 mg/dL1.3–3.5 mmol/L
Term34–119 mg/dL1.9–6.6 mmol/L
Child40–80 mg/dL2.2–4.4 mmol/L
PROTEIN4,12,13
Preterm65–150 mg/dL0.65–1.5 g/L
0–14 days79 (±23) mg/dL†0.79 (±0.23) g/L†
15–28 days69 (±20) mg/dL†0.69 (±0.20) g/L†
29–42 days58 (±17) mg/dL†0.58 (±0.17) g/L†
43–56 days53 (±17) mg/dL†0.53 (±0.17) g/L†
Child5–40 mg/dL5–40 mg/dL
OPENING PRESSURE (LATERAL RECUMBENT POSITION4,14)
Newborn8–11 cm H2O
1–18 yr11.5–28 cm H2O∗
Respiratory variations0.5–1 cm H2O

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WBC, White blood cell.

∗ Up to 90th percentile.

† Mean (±SD).

TABLE 27-4

Characteristics of Synovial Fluid in the Rheumatic Diseases

GroupConditionSynovial ComplementColor/ClarityViscosityMucin ClotWBC CountPMN (%)Miscellaneous Findings
NoninflammatoryNormalNYellow
Clear		↑↑G<200<25
Traumatic arthritisNXanthochromic
Turbid		↑F–G<2000<25Debris
OsteoarthritisNYellow
Clear		↑F–G1000<25
InflammatorySystemic lupus erythematosus↓Yellow
Clear		NN500010Lupus cells
Rheumatic feverN–↑Yellow
Cloudy		↓F500010–50
Juvenile rheumatoid arthritisN–↓Yellow
Cloudy		↓Poor15,000–20,00075
Reiter syndrome↑Yellow
Opaque		↓Poor20,00080Reiter cells
PyogenicTuberculous arthritisN–↑Yellow-white
Cloudy		↓Poor25,00050–60Acid-fast bacteria
Septic arthritis↑Serosanguineous
Turbid		↓Poor50,000–300,000>75Low glucose, bacteria

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F, Fair; G, good; H, high; N, normal; PMN, polymorphonuclear leukocyte; WBC, white blood cell; ↓, decreased; ↑, increased.

From Cassidy JT, Petty RE. Textbook of Pediatric Rheumatology. 5th ed. Philadelphia: WB Saunders, 2005.

III. Conversion Formulas

A. Temperature
1. To convert degrees Celsius to degrees Fahrenheit:

([9/5]×Temperature)+32

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2. To convert degrees Fahrenheit to degrees Celsius:

(Temperature−32)×(5/9)

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B. Length and Weight
1. Length: To convert inches to centimeters, multiply by 2.54.
2. Weight: To convert pounds to kilograms, divide by 2.2.