Abnormal Findings in the Complete Blood Count
The abnormal findings are: WBC 22.4 (elevated), Hgb 11.0 (low), HCT 32.0% (low), and PLT 78 (low/thrombocytopenia). The head CT, EKG, and ABG are all within normal limits.
Complete Blood Count Analysis
White Blood Cell Count (WBC: 22.4 × 10³/μL)
- Markedly elevated (normal range: 4.5-11.0 × 10³/μL)
- This represents leukocytosis, which can indicate:
- Infection or inflammatory process
- Stress response
- Hematologic disorder
- Medication effect (e.g., corticosteroids)
The absolute neutrophil count (ANC) of 12.6 × 10³/μL is also elevated (normal: 1.5-8.0 × 10³/μL), suggesting a neutrophilic leukocytosis pattern.
Hemoglobin (11.0 g/dL) and Hematocrit (32.0%)
- Both are low, indicating anemia
- Normal hemoglobin: Men 13.5-17.5 g/dL, Women 12.0-15.5 g/dL
- Normal hematocrit: Men 38.3-48.6%, Women 35.5-44.9%
In the context of giant cell arteritis screening, anemia is a common finding with 87.4% sensitivity for the disease 1, though it has low specificity (31.4%). However, anemia is nonspecific and can result from numerous causes including chronic disease, blood loss, nutritional deficiency, or bone marrow suppression.
Platelet Count (78 × 10³/μL)
- Significantly low (normal range: 150-400 × 10³/μL)
- This represents thrombocytopenia
- Platelet count <100 × 10³/μL is an independent risk factor for abnormal head CT findings in certain populations 2
- Requires urgent evaluation as it increases bleeding risk
The combination of elevated WBC, anemia, and thrombocytopenia suggests a systemic process affecting multiple cell lines. This pattern warrants immediate investigation for:
- Bone marrow disorders (myelodysplastic syndrome, leukemia, aplastic anemia)
- Severe infection with bone marrow suppression
- Autoimmune disorders
- Medication-induced cytopenias
- Hypersplenism
Normal Findings
Head CT
The findings of "mild atrophy consistent with normal aging; no evidence of lesion, edema, or hemorrhage" are normal for age-related changes 3, 4. No acute intracranial pathology is present.
Electrocardiogram
"Mild sinus tachycardia; otherwise normal" is not pathologically abnormal. Sinus tachycardia is a physiologic response to various stimuli (pain, anxiety, fever, anemia, hypovolemia) rather than a primary cardiac abnormality 5, 6, 7. The absence of ST-segment changes, T-wave inversions, conduction abnormalities, or arrhythmias indicates no acute cardiac pathology.
Arterial Blood Gas
- pH 7.42 (normal: 7.35-7.45)
- PCO₂ 41 mm Hg (normal: 35-45 mm Hg)
- PO₂ 90 mm Hg (normal: 75-100 mm Hg)
- HCO₃ 26 mEq/L (normal: 22-28 mEq/L)
- SaO₂ 97% (normal: 95-100%)
All ABG values are within normal limits 8, 9. There is no evidence of respiratory failure, acid-base disturbance, or hypoxemia.
Clinical Significance
The pancytopenia pattern (low hemoglobin, low platelets) combined with leukocytosis is the most concerning finding and requires:
- Peripheral blood smear examination
- Comprehensive metabolic panel
- Coagulation studies (PT/INR, aPTT)
- Consideration of bone marrow biopsy
- Evaluation for underlying malignancy, infection, or autoimmune disease
The thrombocytopenia is particularly important as it increases bleeding risk and may contraindicate certain procedures or anticoagulation if needed 2.