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HelpTest Code LAB1748 CBC with Auto Differential
Additional Codes
Includes: WBC, RBC, Hemoglobin, Hematocrit, Platelet count, RBC indices, and WBC differential
Testing Algorithm
If platelet count is <50 K/cumm then an IPF (immature platelet fraction) will be performed and reported at an additional charge
Performing Laboratory
St. Louis Children's Hospital - Hematology
Specimen Requirements
Patient Preparation: None
Container/Tube
Preferred: Lavender-top (EDTA) tube
Acceptable: Lavender-top (EDTA) samplette/microtainer
Collection Volume:
| Vacutainer: | 2.0 mL (minimum 0.5 mL) |
| Microtainer: | Full tube (minimum 0.3 mL) |
Submission Container/Tube: If specimen is coming from outside facility, send whole blood in original collection container.
Special Instructions: Immediately invert tube gently 8-10 times after collection to ensure proper mixing of blood and anticoagulant (this will avoid specimen clotting). Do not overfill tube.
Sample Rejection
Mislabeled or unlabeled specimens
Clotted specimens
Specimens collected above an IV line (contaminated)
Logistics
Test Availability: Monday-Sunday
Cut-off time: None; performed as received
Turnaround Time: Same day; 2 hours from receipt in performing lab
Reference Values
Reference Interval:
| AGE | WBC | RBC | HGB | HCT | NRBC Abs |
| K/cumm | M/cumm | g/dL | % | K/cumm | |
| <3 days: | 9.0-30.0 | 3.9-6.0 | 14.5-22.5 | 45.0-66.0 | 0.00-2.50 |
| 3 days-2 weeks: | 5.0-21.0 | 3.6-6.2 | 12.5-20.5 | 39.0-63.0 | 0.00-0.05 |
| 2 weeks-1 month: | 5.0-20.0 | 3.0-5.4 | 10.0-18.0 | 31.0-55.0 | 0.00-0.01 |
| 1-6 months: | 6.0-17.5 | 2.7-4.9 | 9.0-14.0 | 28.0-42.0 | 0.00-0.01 |
| 6 months-2 years: | 6.0-17.5 | 3.7-5.3 | 10.5-13.5 | 33.0-39.0 | 0.00-0.01 |
| 2-6 years: | 5.0-15.0 | 3.9-5.3 | 11.5-13.5 | 34.0-40.0 | 0.00-0.01 |
| 6-12 years: | 4.5-13.5 | 4.0-5.2 | 11.5-15.5 | 35.0-45.0 | 0.00-0.01 |
| >or=12 years, Female: | 3.8-9.9 | 3.9-5.2 | 11.9-15.5 | 35.6-45.5 | 0.00-0.01 |
| >or=12 years, Male: | 3.8-9.9 | 4.3-5.8 | 13.0-17.5 | 38.9-50.3 | 0.00-0.01 |
| AGE | MCH | MCHC | MCV |
| pg | g/dL | fL | |
| <1 week: | 28.0-40.0 | 28.0-38.0 | 88.0-123.0 |
| 1 week-1 month: | 25.0-35.0 | 29.0-37.0 | 85.0-123.0 |
| 1-6 months: | 25.0-35.0 | 29.0-37.0 | 74.0-115.0 |
| 6 months-2 years: | 23.0-31.0 | 30.0-36.0 | 70.0-78.0 |
| 2-6 years: | 24.0-30.0 | 32.7-35.5 | 75.0-87.0 |
| 6-12 years: | 25.0-33.0 | 32.7-35.5 | 77.0-95.0 |
| >or=12 years (all) | 27.1-33.3 | 32.3-35.7 | 81.3-96.4 |
| RDW CV | |
| <3 day: | 15.0-20.0% |
| 3 days-1 month: | 13.0-19.0% |
| 1-6 months: | 12.0-16.0% |
| >or=6 months: | 11.1-14.9% |
Platelet count (all ages): 150,000-400,000 K/cumm
MPV (all ages): 9.1-12.3 fL
| IPF (if applicable) | |
| <6 months: | 1.5-7.0% |
| 6 months-12 years: | 1.1-5.0% |
| 12-18 years: | 1.6-6.5% |
| ≥ 18 years: | 1.6-10.1% |
DIFFERENTIAL
| <4 years | 4-16 years | >or=16 years | |
| K/cumm | K/cumm | K/cumm | |
| Neutrophil Abs: | 1.0-10.2 | 1.5-9.4 | 1.5-6.5 |
| Lymphocyte Abs | 1.2-11.5 | 1.0-7.2 | 0.8-3.3 |
| Monocyte Abs | 0.0-1.2 | 0.1-1.7 | 0.2-0.8 |
| Eosinophil Abs | 0.0-0.5 | 0.1-1.6 | 0.0-0.5 |
| Basophil Abs | 0.0-0.2 | 0.0-0.3 | 0.0-0.1 |
| Immature Gran Abs | 0.0-0.3 | 0.0-0.2 | 0.0-0.1 |
Critical:
| WBC | ||
| <3 days: | <2.0 K/cumm OR >50.0 K/cumm | |
| >or=3 days: | <1.0 K/cumm OR >50.0 K/cumm | |
| Hgb | ||
| <12 years: | <7.0 g/dL | |
| 12-18 years: | <6.0 g.dL | |
| >or=18 years: | <6.5 g/dL OR >19.9 g/dL | |
| PLT - Inpatient: | ||
| <18 years: | <25,000 K/cumm OR >1,000,000 K/cumm | |
| ≥ 18 years: | <20,000 K/cumm OR >1,000,000,K/cumm | |
| PLT - Outpatient or ED patient: | ||
| all ages: | <50,000 K/cumm OR >1,000,000 K/cumm | |
| Differential | ||
| NEUTAB or ANC: | <0.5 | |
| Blast: | Any seen | |
| Promyelocyte: | >20 cells seen | |
All critical test results will be automatically called back initially and every 72 hours thereafter with the exception of outpatient or ED patient results, those will be called every time.
Methodology
see individual component
Limitations
- Red cell fragments, microcytic RBCs or white cell cytoplasmic fragments may interfere with automated platelet counts.
- Instrument may trigger a reflex to a manual smear. All specimens that reflex will have a slide smear be manually reviewed and if match auto-diff, the auto differential will be reported, otherwise a manual differential will be reported and resulted by lab.
Additional Information
FOR SLCH CORE LABORATORY USE ONLY
Lab Processing Instructions: DO NOT SPIN. Give specimen directly to Hematology bench
Processed Volume: NA
Analyte Stability:
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood (unprocessed) | Ambient | 24 hours |
| Refrigerated | 24 hours | |
| Frozen | unacceptable |
NOTE: refrigerated specimens must be warmed to room temperature before analysis.
Test Classification and CPT Code
85027
85055 - IPF (if applicable)
LOINC
WBC: 6690-2
RBC: 789-8
Hgb: 718-7
Hct: 4544-3
Plt: 777-3
IPF (if applicable): 71693-6
Last Reviewed
07/2025