CBC

RBC                 F: 4.2-5.4 mil/uL
                        M: 4.7-6.1 mil/uL

WBC                5,000-10,000 mil/uL

MCV                80-95 mm^3                        mean corpuscular volume

MCH                27-31 pg/cell                       mean corpuscular Hgb

TIBC                250-460 mcg/dL                  total iron binding count

Iron                  F: 60-160 mcg/dL

                         M: 80-180 mcg/dL

Platelets:          150,000-400,000 mm^3

Hgb:                 F: 12-16 g/dL

                         M: 14-18 g/dL

Hct:                  F: 37-47%

                         M: 42-52%

Pt/INR*           11-12.5 seconds/2-3

*on warfarin

(a)PTT             30-40 seconds (x1.5-2 on anticoagulants)

What is Hct and Hgb?  How do you keep them straight?

Hct, (hematocrit) is the portion of the blood that is actually red blood cells.  When you spin the blood sample down in the lab, the red blood cells will fall to the bottom (due to weight), and that percent of the blood is the actual count—so basically in a female blood sample, 37-47% of test tube will be red blood cells.

Hgb (hemoglobin) is what’s inside of a red blood cell.  There’s a lot of molecules of hemoglobin inside of each red blood cells.  Actually there’s approximately 280 million hemoglobin molecules in one red blood cell. 

MCV, the mean corpuscular volume is a measurement of the average volume of the red blood cells.  This differential is done to figure out what the cause is of anemia.  Now, obviously if there is an acute hemorrhage in a healthy, young adult you would expect to see normocytic anemia (normal ranged MCV). 

If the MCV is microcytic (<80 mm^3), then that means the red blood cells are being shunted into circulation before they are ready.  Smaller red blood cells have less volume, so when you shine a light through it it’ll appear paler (hypochromic). The two most common cause of microcytic anemia are iron deficiency anemia, and thalassemia (autosomal recessive disorder of abnormal hemoglobin formation).  Both of these conditions cause the body to be deprived of O2, which in turn forces the body to create RBCs faster than normal to compensate.

If the MCV is macrocytic (>95 mm^3), that means that the red blood cells are bigger than normal.  There are several conditions that cause macrocytic anemia.  One of those conditions is megaloblastic anemia, which occurs when the cells don’t have enough vitamins (folate and B12) and can’t replicate DNA quickly enough to divide, so the cells becomes larger and larger until they become macrocytic.