1. DEFINITION
1.1. PACKED RED BLOOD CELLS IN A GIVEN BLOOD VOLUME
2. METHODS OF MEASUREMENT
2.1. MANUAL MEASUREMENT
2.1.1. USES DIRECT TECHNIQUES
2.1.2. TYPES
2.1.2.1. MICROHEMATOCRIT
2.1.2.1.1. "ADAM'S METHOD"
2.1.2.1.2. USE CAPILLARY TUBE
2.1.2.2. MACROHEMATOCRIT
2.1.2.2.1. OBSOLETE
2.1.2.2.2. 5 SUBTYPES
2.2. AUTOMATED MEASUREMENT
2.2.1. REPLACED MANUAL METHODS
2.2.2. 1890s
2.2.3. MORE ACCURATE AND PRECISE
2.2.4. MACHINE USED
2.2.4.1. BECKAMN COULTER COUNTER
2.2.4.2. ABBOTT CELL-DYN
2.2.4.3. SIEMENS ADVIA
2.2.4.4. SYSMEX XN SERIES
3. NORMAL VALUES
3.1. DEPENDS ON AGE & GENDER
3.1.1. NEWBORNS
3.1.1.1. 38-68%
3.1.2. 1 MONTH TO 1 YEAR OLD
3.1.2.1. 32-51%
3.1.3. CHILDREN
3.1.3.1. 34-49%
3.1.4. MALE
3.1.4.1. 40-54%
3.1.5. FEMALE
3.1.5.1. 35-49%
4. CLINICAL SIGNIFICANCE
4.1. MEASURES THE AMOUNT OF RBC TO MAKE AN ACCURATE DIAGNOSIS
5. RULE OF THREE
5.1. FOR NORMAL RBC
5.1.1. NORMOCHROMIC
5.1.2. NORMOCYTIC
5.2. FOR COUNTERCHECKING
5.3. ABNORMAL RBCs: REPORTED AS IS
5.4. RBC COUNT x3 = Hgb
5.5. Hgb x3 = Hct%
6. reported in percentage (%) or L/L
7. FACTORS AFFECTING HEMATOCRIT LEVELS
7.1. INCREASED
7.1.1. PATHOLOGIC
7.1.1.1. DEHYDRATION
7.1.1.2. ERYTHROPOIETIN DRUG ABUSE
7.1.1.3. LUNG AND HEART DISEASE
7.1.1.4. POLYCYTHEMIA VERA
7.1.1.5. CERTAIN TUMORS
7.1.2. PHYSIOLOGIC
7.1.2.1. NEWBORNS
7.1.2.2. HIGH ALTITUDE
7.2. DECREASED
7.2.1. PATHOLOGIC
7.2.1.1. ANEMIA
7.2.1.2. MALNUTRITION
7.2.1.3. HEMORRHAGE
7.2.1.4. IRON DEFICIENCY
7.2.1.5. OVERHYDRATION
7.2.1.6. CHRONIC KIDNEY DISEASE
7.2.1.7. INADEQUATE IRON UPTAKE
7.2.2. PHYSIOLOGIC
7.2.2.1. PREGNANCY