Blood Collection and Composition Quiz 1

Study Notes

Blood Composition

Adult males have 5-6 liters of whole blood; adult females have 4-5 liters.
Blood is comprised of 55% liquid (plasma) and 45% formed elements (cells).
Plasma consists of 93% water and 7% solids (proteins and albumins).
Solid components include RBCs (2.25 L, 45%), WBCs (0.037 L, 1.6%), and platelets (0.0065 L).

Physical Characteristics of Blood

Blood is a fluid state in vivo due to heparin presence.
It appears red due to hemoglobin content.
Slightly alkaline with a pH range of 7.35-7.45, influenced by bicarbonates, CO2, electrolytes, and proteins.
Specific gravity averages at 1.055, within the range of 1.045-1.065.
Blood is thick and viscous, 3.5 to 4.5 times thicker than water, and has a salty taste from plasma electrolytes.

Blood Collection and Handling

It's essential to record protein names for sample identification.
Patients should fast for at least 12 hours to maintain accurate WBC counts.
Blood extraction is recommended between 8:00 and 9:00 AM after patient rest.
Misleading results can occur due to pre-collection factors (recent meals, smoking, physical activity, stress) or collection/handling errors (diurnal variance, posture changes, hemoconcentration, incorrect anticoagulant use).

Methods of Blood Collection

Blood can be obtained via skin puncture, venipuncture, or arterial puncture.

Skin Puncture

Collects a mixture of arterial and venous blood, primarily arteriolar in origin.
Contains interstitial and intracellular fluids, with PCV, RBC count, and Hgb slightly higher than in venous blood.
Higher leukocyte and neutrophil counts by 8%, and monocyte count by 12% compared to venous blood.
Platelet counts are lower due to adherence at the puncture site.

Preferred Sites for Skin Puncture

Palmar surface of the 3rd or 4th finger.
Lateral plantar heel surface for newborns.
Plantar surface of the big toe.
Margin of the earlobe (least preferred site).

Application of Micro Sample Collection

Suitable for infants under 6 months, young children, adults with poor veins, or patients with thrombotic tendencies.

Equipment for Micro Sample Collection

Appropriate capillary tubes (Caraway pipette, heparinized or plain capillary, Sarstedt system).
Microtainers and Unopettes.
Becton Dickinson microtainer for blood collection.

Puncturing Devices

Needles such as Glover's needle (3-cornered, short) and Hagedorn needle (large with cord).
Blades like Bard Parker Blade #1 or scalpel blades.
Additional devices include lancets, glass capillary pricker, pin, and cork pricker.
A lancet length of 1.75 mm is preferred to avoid penetrating the bone; depth of incision should be controlled.

Description

Test your knowledge on the components of blood, including its physical characteristics and the role of anticoagulants in blood collection. This quiz covers essential facts about blood volume in adult males and females, as well as the composition of liquid and solid elements in blood.