MCHC 35.9 g/dL in Adult with Acute Bacterial Infection on Antibiotics
An MCHC of 35.9 g/dL is completely normal and indicates that red blood cell hemoglobin concentration is within the physiologic reference range (32-36 g/dL), providing no diagnostic information about the bacterial infection or its treatment response. 1, 2
Clinical Interpretation
A normal MCHC indicates that red blood cells contain a normal concentration of hemoglobin per unit volume of packed cells, which is expected in acute bacterial infections without concurrent hematologic abnormalities 1, 2
MCHC values above 36 g/dL are not physiologically possible due to hemoglobin solubility limitations, while values significantly above the reference range may indicate specific hemolytic anemias requiring peripheral smear examination 3
In the context of acute bacterial infection on antibiotic therapy, a normal MCHC simply confirms the absence of red blood cell abnormalities and should not influence antibiotic selection or duration 1, 2
What MCHC Does NOT Tell You
MCHC does not reflect infection severity, antibiotic efficacy, or treatment response—these require clinical assessment including fever resolution, vital sign normalization, and symptom improvement 4
MCHC does not indicate whether the chosen antibiotic regimen is appropriate—this depends on the infection source, patient comorbidities, and local resistance patterns 4
A normal MCHC does not rule out anemia of chronic disease or acute blood loss, which would be reflected in hemoglobin concentration and hematocrit, not MCHC 1, 2
Critical Pitfall to Avoid
Do not use MCHC to guide antibiotic therapy decisions—focus instead on clinical stability criteria (afebrile for 48-72 hours, hemodynamic stability, improved respiratory symptoms, ability to take oral medications) to determine treatment duration and response 4
Automated cell counters may underestimate MCHC in dehydrated or undeformable cells, but this technical limitation is irrelevant in routine bacterial infection management 1