The Hematologic System
(blood, blood cells, lymph, and organs involved in…
The Hematologic System
(blood, blood cells, lymph, and organs involved in blood formation/storage)
Bone Marrow: the tissue responsible for blood formation. Produces red blood cells (RBCs, erythrocytes), white blood cells (WBCs. leukocytes)
Blood stem cells: immature, unspecialized cells. Can become RBCs, WBCs, platelets, etc.
Drugs affecting hematologic system
- Anticoagulants: interfere with one or more steps involved in the blood clotting cascade. Prevent new clots, prevent extension of formed clots, do not break down existing clots.
(cooked cabbage is high in Vit K)
- Fibrinolytic drugs: selectively break down fibrin threads present in formed blood clots by activating plasminogen to its active form plasmin.
- Platelet inhibitors: prevent platelet aggregation or activation. Ex. aspirin
Erythropoietin: given to dialysis patients to decrease number of blood transfusions needed
hypochromic: decreased color in rbc
pantocytopenia: all cellular components of the blood are decreaed
Always monitor H&H for active bleeding (upper GI bleeding- samvostatin)
ESR/sed rate: how fast the rbc settles down;
Serum ferritin: transports iron
Patient History Assessment
- Age and gender (males have higher H&H)
- Demographic data (certain locations have less oxygen)
- Current and past individual and family hx
- Surgical hx (splenectomy, gastric surgeries)
- Assess liver fx, the presence of known immunlogic or hematologic disorders
- Current drug use
- Past and current use of medications, herbs, supplements (St. John's wort, ginko)
- Manifestations that may indicate liver problems (jaundice, anemia, and gallstones)
- Previous radiation therapy
- Occupation, hobbies, and location of housing
- Medications within last 3 weeks, esp antibiotics
- use of "blood thinners"
- Nutritional status: record anything eaten during the previous week
- Alcohol consumption
- Disorders, injuries, or transplants involving liver, kidney, or spleen
- Exposure to radiation or chemicals
- Military history (malaria)
- Impact on usual roles and responsibilities
- Diet high in Vit K (inc rate of blood clotting)
- Assess ability to understand and follow instructions related to procedures and tests
- Family history (hemophilia, frequent nosebleeds, postpartum hemorrhage, excessive bleeding, heavy bruising, sickle cell)
- Lymph node swelling
- Excessive bruising or bleeding (hemorrhage, gastric ulcers, etc)
- Dialysis pt (frequent blood transfusion causing
- Amount and duration of bleeding after dental work
- If menorrhagia is present
- High risk sexual behaviors
- Whether or not pt has shortness of breath on exertion, palpitations, frequent infections, fever, recent weight loss, headache, paresthesias
- s/s of anemia (vertigo, tinnitus, sore tongue)
- Inspect skin, sclera, conjunctiva, and mucous membranes for pallor & jaundice
- Assess nail beds for pallor of cyanosis
- Assess gums for active bleeding in response to pressure or brushing
- Inspect for petichiae and large bruises
- Whether there is bleeding from sites such as NG tube, central lines, peripheral IV, FC.
- Check skin turgor
- Ask about itching
- Asses body hair distribution patterns
- Check for pallor or ulceration of the mouth mucosa (smooth tongue: pernicious anemia, beefy red tongue: nutritional deficiencies, fissures)
- Inspect and palpate all lymph node areas (groin for lymphomas)
- Assess depth and rate of respirations before and after activity
- Note whether pt can complete 10 word sentence w/o stopping for breath
- Observe for distended neck veins, edema, signs of phlebitis
- Auscultate for murmurs, gallops, irregular rhythms, abnormal BP
- Inspect urine for color (hematuria)
- Test urine for proteins
- Examine skin over superficial bones, including the ribs and sternum by applying firm pressure with fingertips
- Assess joint ROM and observe for swelling
- Palpate the LUQ gently for an enlarged spleen
- Palpate the RUQ of the abdomen for the liver
- Obtain a stool specimen for occult blood testing (ulcers)
- Mental status exam
Tests of Cell Number and Fx
- Peripheral blood smear: provides info on size, shape, and approx. proportions of diff blood cell types
- CBC: number of RBCs, WBCs, hematocrit, hemoglobin level
- Reticulocyte count: indicates that RBCs are being released by the bone marrow before they mature.
- platelet count: thrombocyte count
- Coombs' test: used for blood typing
Tests that measure bleeding & coagulation
- Prothrombin time: measures how long blood takes to clot (reflects clotting factors II, V, VII, and X). Normal 11-12.5 sec
- INR: measures the same process as the PT by establishing a normal mean or standard for PT. Calculated by dividing the pts PT and the standard PT. Normal 0.7-1.8
- Partial thromboplastin time: assesses the intrinsic clotting cascade and the action of factors II, V, VIII, IX, XI, and XII. Normal 25-35 sec.
*liver disease can affect PTT
- Platelet aggregation: testing by mixing the pt's plasma with an agonist substance that should cause clumping. (Agonists inc: collagen, epinephrine, adenosine diphosphate, ristocetin)
- Radioisotopic imaging are used to evaluate the bone marrow for sites of active blood cell formation and sites of iron storage
- Radioactive colloids are used to determine organ size and liver and spleen fx.
*Pt is given a radioactive isotop about 3 hrs before the procedure. Must lie still for an hour during scan. No special prep or follow-up care is needed.
Bone Marrow Aspiration and Biopsy
- Aspiration: cells and fluids are suctioned from the bone marrow
- Biopsy: solid tissue and cells are obtained by coring out an area of bone with a large-bore needle
(done for leukemias or any kind of blood cell abnormalities)
- Order and signed consent
- Check the facility's procedure manual and the hematology manual to determine how to handle the specimen.
- Relieve anxiety by providing accurate info and emotional support.
- Explain the procedure and reassure you will stay
- Tell pt to expect stinging from anesthetic and a heavy pressure or pushing while the needle is being inserted
- Crunching sound or scraping sensation is normal
- Explain brief sensation of painful pulling will be experienced.
- Assist the pt onto the exam table and expose site (iliac crest or possibly sternum)
- Pt may recieve a mild tranquilizer or rapid-acting sedative (lorazepam, etomidate)
- Guided imagery
- Apply external pressure until hemostasis is ensured. (10 min or more; pressure dressing or sandbags may be used)
- Post-procedure prevent excessive bleeding
- Cover the site with dressings and observe for 24 hrs for s/s of bleeding or infection
- Mild analgesic may be given for discomfort as well as ice packs over the site to minimize bruising.
- Instruct the pt to inspect the site q2h and note the presence of active bleeding
- Advise the pt to avoid contact sports for 24 hrs