Understanding and Interpreting Hemograms

• The document focuses on understanding and interpreting hemograms (complete blood counts) in adults and children, covering key indications, interpretations, and potential anomalies found during analysis

Educational Objectives

• Argue for the main reasons to request blood count
• Discuss interpreting the results
• When should one begin working towards a diagnosis

Knowledge Hierarchy

• Familiarity, the professor has set up the rank A knowledge that is required
• Must achieve 14/20 on Rank A questions
• Understand how to quantify information from a blood count
• Know what is considered a quality parameter in a blood count
• Need to understand when is requesting blood count is urgent to allow immediate therapeutic intervention (platelet transfusion, red cell concentrate)
• The abnormalities present in different blood cell lines and their primary etiologies
• Need to know: Hb levels in children and anaemia
• Need to know: blood cell lines levels in children

Hemogram (Complete Blood Count)

• Blood counts are the most common lab test done in France
• Peripheral venous blood sample with a dry anticoagulant
• EDTA tubes are purple-topped, used for quantitative abnormality analysis
• EDTA is a dry anticoagulant with no dilution factor
• Perform measurements prior to procedures than can change the values
• Normal values dependent on age, sex, and ethnicity

Quantitative Data in CBC

• A CBC enables qualitative and quantitative analysis of blood cells

Red Blood Cell Indices

• Critically important when examining anemia
• Hemoglobin Concentration (Hb): decreased hemoglobin = anemia, increased hemoglobin = polyglobulia.
• Hematocrit (Hct): Usually in agreement with the hemoglobin
• Red Blood Cell Count (RBC): Only examined in specific circumstances
• Mean Corpuscular Volume (MCV): Used to classify anemia, with the other 2 parameters available, helps determine normocytic, microcytic and macrocytic aneamia, normal range: 80-100fL

Mean Corpuscular Hemoglobin Concentration (MCHC)

• Average concentration of hemoglobin in a red blood cell, useful for determining hemoglobin chromia
• Can define the chromia of hemoglobin-Is it hypochromic or normochromic
• Size and color of RBCs are key when defining anaemia (micro/normo/macro and hypo/normo chromic)
• It is essential to characterize a macro/normo/micro-cytic and hyper/normo-chromic
• If one parameter is missing then it is not valid

Mean Corpuscular Hemoglobin (MCH)

• Weight of hemoglobin per red blood cell
• Lower TCMH suggests iron deficiency

Platelet Count

• Determines a thrombopenia or thrombocytosis- abnormally low and high

White Blood Cell Count

• Must know normal values by age
• The total WBC count differs from polymorphonuclear neutrophils (PMNs), important to differentiate these
• Leukocyte formulas helps differentiate leukocyte subpopulations
• Hyperleukocytosis does not equal polynucleosis

Leukocyte Formula

• Must be indicated in absolute value and not in percentage
• Normal values vary with age, sex, ethnicity, & underlying conditions (altitude, pregnancy, tobacco/alcohol)
• When reading results make sure to look at Hb,MCV,MCHC, Leukocytes, Leukocyte Formula & Platelets

Physiological Variations

• Values vary with:
  • Age
  • Ethnicity
  • Altitude
  • Pregnancy
  • Consumption of Alcohol and/or Tobacco

Complete Blood Count Indications

• Always consider/cross-reference clinical symptoms and test results
• Anticipate any abnormalities and have an idea of what symptoms may arise

Signs Indicating Decrease in One or More Cell Lines

• These symptoms reflect a reduction or increase in cell lines

Anemic Syndrome

• Symptoms include paleness, fatigue, dyspnea, tachycardia, possible systolic murmur
• Additional clinical elements exist that depend on the type present
• Jaundice suggests hemolytic anemia
• Unusual skin suggests iron deficiency anemia

Hemorrhagic Syndrome

• Indicates thrombopenia or a thrombopathy
• Relates to platelets, causing anemia if patient bleeds, caused by purpura, hematoma and ecchymoses

Unexplained Infectious Syndrome

• Can be persistent, recurring, or severe (fever, angina)
• With fever, infections are most probably present with 2 consequences
  • Increase of one line (lymphocytes, polynuclear) from a bacteria or virus
  • Neutropenia or agranulocytosis because if patient has leukemia which will cause infectious disease

Pre-Therapeutic Blood Counts

• Draw blood before any therapy to get accurate results
• If suspecting deficiency in B12 or iron, get blood draw before transfusion

Signs Indicating Increase in One or More Cell Lines

• Erythrosis or Pruritis suggest increased hemoglobin
• Arterial or Venous Thrombosis suggests exploring haemostasis
• Tumor Syndrome
  • Enlarged Spleen
  • Adenopathies
  • Lymphoproliferative Syndrome
  • Nothing Else

Alteration of General State

• Asthenia
• Weight Loss
• Sweats
• Nodules
• Long Term Fever
• Do a CBC Impreratively
• Indications for Systematic CBC Monitoring
  • Pregnancy
  • Icterus
  • Decubitus
  • Drug Treatment
  • Pre-Op

Indications for Urgent CBCs

• Shock
• Intense Paleness
• Ulceronecrotic Angina
• High Fever During Chemo
• Fever resistant to antibiotics
• Hemorrhagic Syndromes
• Hematopoietic Tumor Syndrome

Anomalies Requiring Urgent Care

• Hb < 60 g/L
• Hb < 11g (newborn): anemia
• Ht >60% (adults) : thrombosis
• Neutropenia <0.5G/L: agranulocytosis
• Thrombopenia < 20 G/L
• Hyperleukocytosis with > 20 G/L immature cells

Blood Smear

• Used for manual differentiation, machines can’t separate new populations
• Look for all cells and abnormalities

Indications

• Abnormal RBC Index
• Abnormal Platelet Count
• Abnormal WBC Count
• Abnormal Automatic Graph

How to Perform

• Drop blood on slide, dry, then stain

Red Blood Cell Anomalies

• Anisocytosis: Variation in size
• Poikilocytosis: Variation in shape
• Target Cells: Sign of Disease
• Teardrops: Fibrosis
• Schizocytes: RBC fragmentation common in microangiopathic hemolytic anemias (MAHA)
• Sickle Cells: Sickle Cell Anemia
• Jolly Bodies: DNA Fragment (patient doesnt have a spleen)
• Paludism: Parasite that comes from the spleen, body attacks itself and they are not filtered

Platelet Abnormalities on Smear

• Platelet clumps indicate false automated count due to EDTA
• Platelets may stick to WBCs

Abnormal Cells

• Important to know what to look for, there are also causes (malignign/benign)
• Lymphocytes : syndrome mononucleosique
• Atypical LYMPHOCYTES: syndrome lymphoproliferatif
• Blasts: must differentiate WBC

Principal Lines Interpertation

• Check teaching and LISA sheets to learn
• You MUST know normal value (man, women, baby) and know what is a RBC line

Erythrocyte Line

• Poly globulin = ↑ RBC but ↑ Hb
• If lower then look at the VGM which will show micro/macro cytosine of individual, VGM is individual each person is usually stable

Leukocytes Lines

• Normal adult value: 4-10 G/L
• PNN, lymphocytes and monocytes must be determined
• If PNN is high could be: bacterial infection
• NN value is higher (10-26 G/L) also in pregnant

Myelocytes

• Stem cell passages Reactions:
  • Infections (septicemia)
  • Haemolytic Anemia Malignant:
  • SMP

Neutropenia

• PNN<1.5 G/L unless ethnicity is known (Afro-Caribbean)
• Could be vascular, so you must eat then blood count (epinepherine secreted)

Eosinophils (PNE) and Basophils (PNB)

• For rise in PNE may be parasitic (check courses)
• For rise in PNB look out for myeloproliferative syndrome (rare)

Lymphocytes

• Virals
• Mono in teens
• Leukemia if not or chronic Leukemia Lymphoid

Lymphopenia

• Always check patient sex/ethnicity
• If infection it means that it is vital

Monocytes

• If there is mono nucleosis then most likely bacterial infection
• Chemo 1st line is monocyte, it then becomes leukaemia
• Its chronic so get 2nd opinion, and monocytopenies are rare

Platelet lines

• Newborn (15 days to 6 months) 150-600 g/l of platelets and normal values are always 150–400 G/L that are either age or sex so make sure that its true and consistent between clinical and biology

Good to know/learn:

• Anemia
• Neutropenia (neutrophils number )
• Leukopenia (number of globals white)

Pancytopenia

• Myeloid with an neutropenia, anemia or thrombocytopenia

Diagnostic Approach

• Know how to identify and where they originated from age
• DONT fall for traps: anemia or thrombopénies
• Cyto penia or ↑ has a oetiology
• To determine anémie look at RBC AND VGM which is the reticulocytes.
• Cyto "osis has a reaction in the central region

Main Points

• Essential to remember that blood count is the most prescribed exam to be completed before therapy
• Learn the various data with age/sex
• Normal hemoglobin, with an suspect to poly globulin
• Leucocitary and interpret results
• Know values to watch for