ERRORS + CRITICAL VALUES

RBC count: WBCs > 100,000/uL

False high

RBC count: Giant platelets

False high

RBC count: cryoglobulin, cryofibrinogen

False high

RBC count: autoagglutination

False low

RBC count: cold agglutinins

False low

RBC count: In vitro hemolysis

False low

RBC count: microcytes, schistocytes, clotting

False low

MCV: autoagglutination

False high

MCV: WBC >50,000/uL

False high

MCV: Cold agglutinin

False high

MCV: old specimen

False high

MCV: hyperosmolar state (uncontrolled DM)

False high

MCV: Reduced red cell deformability

False high

MCV: cryoglobulin, cryofibrinogen

False low

MCV: giant platelets

False low

MCV: In vitro hemolysis

False low

MCV: swollen red cells

False low

MCH: lipemia, icterus, chylomicrons

False high

MCH: WBC > 50,000/uL

False high

MCH: Spuriously high Hgb

False high

MCH: spuriously low RBC

False high

MCH: Spuriously low Hgb

False low

MCH: spuriously high RBC

False low

MCHC: cold agglutinins

False high

MCHC: autoagglutination

False high

MCHC: clotting

False high

MCHC: hemolysis

False high

MCHC: spuriously high Hgb

False high

MCHC: falsely low Hct

False high

MCHC: WBC >50,000/uL

False low

MCHC: Falsely low Hgb

False low

MCHC: spuriously high Hct

False low

Hgb: lipemia, icterus, chylomicrons

False high

Hgb: lysis-resitant RBCs with abnormal Hgb

False high

Hgb: WBC > 20,000/uL (>20 × 10⁹/L)

False high

Hgb: platelet count >700 × 10⁹/L

False high

Hgb: parenteral nutrition

False high

Hgb: hypergammaglobulinemia

False high

Hgb: cryoglobulin, cryofibrinogen

False high

Hgb: in vitro hemolysis

False high

Hgb: heparin

False high

Hgb: hyperbilirubinemia

False high

Hgb: clotting

False low

Microhematocrit: Dehydration

False high

Microhematocrit: Hemoconcentration

False high

Microhematocrit: insufficient centrifugation

False high

Microhematocrit: buffy coat inclusion

False high

Microhematocrit: hyponatremia

False high

Microhematocrit: plasma trapping

False high

Microhematocrit: in vitro hemolysis

False low

Microhematocrit: improper sealing of the capillary tube

False low

Microhematocrit: increased AC conc.

False low

Microhematocrit: introduction of excess tissue fluid

False low

Microhematocrit: hypernatremia

False low

Automated Hct: cryoglobulin, cryofibrinogen

False high

Automated Hct: giant platelets

False high

Automated Hct: WBC >50,000 / uL

False high

Automated Hct: hyperglycemia (>600 mg/dL)

False high

Automated Hct: autoagglutination

False low

Automated Hct: clotting

False low

Automated Hct: in vitro hemolysis

False low

Automated Hct: Microcytic red cells

False low

WBC count: lysis-resistant RBCs with abnormal Hgb

False high

WBC count: nRBCs

False high

WBC count: Megakaryocyte fragments

False high

WBC count: micromegakaryoblasts

False high

WBC count: platelet clumps

False high

WBC count: giant platelets

False high

WBC count: cryoglobulin, cryofibrinogen

False high

WBC count: heparin

False high

WBC count: monoclonal proteins

False high

WBC count: leukemia (especially with chemotherapy)

False low

WBC count: leukoagglutination

False low

WBC count: clotting

False low

WBC count: smudge cells

False low

Neutrophils: Neutrophil aggregation

False low

Neutrophils: neutrophil with hemosiderin granules

False low

Lymphocyte: nRBCs

False high

Lymphocyte: giant platelets

False high

Lymphocyte: platelet clump

False high

Lymphocyte: Malarial parasites

False high

Lymphocyte: hypolobated neutrophils

False high

Monocyte: Large reactive lymphocytes

False high

Monocyte: lymphoblasts

False high

Monocyte: lymphoma cells

False high

Monocyte: immature granulocytes

False high

Eosinophils: Neutrophil with hemosiderin granules

False high

Eosinophils: red cells with malarial pigments

False high

Platelet count: leukemia (especially with chemotherapy)

False high

Platelet count: fragmented cells (in microangiopathic hemolysis)

False high

Platelet count: microorganisms

False high

Platelet count: cryoglobulins, cryofibrinogen

False high

Platelet count: hemolysis

False high

Platelet count: microcytic red cells

False high

Platelet count: red cell inclusions

False high

Platelet count: white cell fragments

False high

Platelet count: platelet clumps

False low

Platelet count: old specimen

False low

Platelet count: partial clotting

False low

Platelet count: giant platelets

False low