Ch. 17, 33, 34 Flashcards
peripheral perfusion
total arterial blood flow through the tissues
central perfusion
blood that is pumped by the heart
clotting
complex, multi-step process by which blood forms a protein-based structure (clot)
bone marrow
- bone forming organ
- produces most blood cells
- involved immune responses
name the accessory organs
liver
spleen
plasma proteins
- albumin
- globulins
- fibrinogens
cells
- RBC (erythrocytes)
- WBC (leukocytes)
- platelets
RBCs
- 120 day life span
- produce Hgb (need iron too)
- production is triggered by tissue oxygenation (erythropoiesis)
- growth factor- erythropoietin
RBC medications
epoetin alfa
- procrit
- epogen
WBC
- inflammatory response
- immunity
- 5000-10000 k
- higher count: infection
- lower count: immunocompromised, at risk for infection bc low count of immune defender cells
WBC medication
- filgrastim (neupogen)
platelets
- aggregation
- stored in spleen
- 1-2 week life span
blood clotting/hemostasis balances
clotting and dissolving factors
blood clotting/hemostasis: 3 sequential processes
- plt aggregation with formation of plt plug
- blood clotting cascade
- formation of complete fibrin clot
platelets need to be activated by
collagen and other substances (exogenous or themselves)
platelet aggregation
- membranes become sticky
- NOT clots
clotting factors
- platelet plug
- clotting factors
fibrinogen activated by
- fibrin by thrombin
(thrombin activated fibrinogen)
prothrombin activated by
prothrombin activated by thrombin
fibrin activated by
fibrin activated by clot
anticlotting forces
plasminogen –> plasminogen activators/thrombin –> plasmin (activated form of plasminogen) –> digestion –>fibrin clot –> fibrin degradation products
hematologic changes associated with aging
- decrease in blood volume with lower levels of plasma proteins
- bone marrow produces fewer blood cells
- total RBC, WBC counts lower
- lymphocytes are less reactive to antigens, and lose immune function
- hemoglobin levels fall after middle-age
hematologic diagnostic assessment
- CBC
- reticulocyte (retic) count - immature rbc have nucleus
hematologic diagnostic assessment in older adults
- plts stay the same
- hgb decrease (think bc RBC decreases)
- WBC does not increase as much with infection
- RBC decreases (think bone marrow suppression)
prothrombin (PT)
- measures how long blood takes to clot
- clotting factors II, V, VII, X
- normal PT 11-12.5 secs
- abnormal values
partial thromboplastin time (PTT)
- assess intrinsic clotting cascade
- clotting factors II, V, VIII, IX, XI, XII
- normal = 32-45 secs
- therapeutic range: 1.5-2x nl
- abnormal values
INR- international normalized ratio
- client’s PT divided by nl PT value
- normal range: 0.7-1.8
- warfarin therapy, want INR to be: 2-3
nursing implications for INR
- monitor based on hospital policy (ie q6h)
- adjust warfarin rate based on INR
abnormal values of PTT
anything outside of 32-45 seconds
- want abnormal PTT value when on heparin therapy
- want 1.5-2x the normal to show heparin is being therapeutic
bone marrow aspiration/biopsy: patient preparation
- provide accurate information and emotional support
- explain procedure
bone marrow aspiration/biopsy: procedure
- iliac crest
- local anesthesia
- aspirate bone marrow to test (think testing leukemia to test RBCs)
bone marrow aspiration/biopsy: follow-up care
- teach to inspect the site every 2 hours for 24 hours
- avoid activity that could result in trauma
- analgesic (aspirin-free) and ice packs
bone marrow aspiration can be used to identify the presence of
Study of the bone marrow can be used to identify the presence of leukemia or other malignancies or to determine the cause of anemia.
acquired immune deficiency syndrome (AIDS)
- Serious worldwide epidemic
- HIV can progress to AIDS
- most common immune deficiency disease in the world
most common immune deficiency disease in the world
AIDS
HIV is a ___ virus
retrovirus that infects human CD4+ T-cells
CD4+ T-Cells direct
immune system defenses
- replicate 100 million times a day
CD4+ T-Cells: types
- memory: remember cells that body has been exposed to
- naive: attack everything
CD4 cells = CD4+ cells = T cells = T lymphocytes (all the same thing, all immune cells that attack invaders)
CD4+ T-Cells: memory cells
those programmed to recognize a specific antigen after it has been previously seen
CD4+ T-Cells: naive cells
non-specific responders
HIV: need to knows
- spread HIV through bodily fluids: blood, semen, sputum, breastmilk
- HIV messes around with the way that the CD4 cell functions: the CD4 now hosts a virus factory, which buds and continuously spreads
- issue with HIV is that the CD4 cells cannot fight infections anymore (immunodeficiency)
HIV life cycle
- free virus
- binding and fusion
- infection
- reverse transcription
- integration
- transcription
- assembly
- budding
- immature virus breaks free of the infected cell
take away: multiple steps for the virus to grow and make babies; this is important because the drugs work on specific steps (this is why we use ie 3 drugs to treat)
effects of HIV infection
- CD4+ T-cells become “HIV factory” to make new viral particles daily
- Gradually, CD4+ T-cell count falls, viral load rises
- Immune systems weakens
- Everyone with AIDS has HIV; not everyone with HIV has AIDS
AIDS and HIV relationship
everyone with AIDS has HIV; not everyone with HIV has AIDS
CD4+ T-Cell Count: normal
800-1000 cell/mm³
CD4+ T-Cell Count: stage 1 HIV
> 500 cell/mm³ with confirming blood test
CD4+ T-Cell Count: intermediate stage HIV
200 – 499 cell/mm³
- Lower the count – patient at risk for bacterial, fungal, viral, cancers, and opportunistic infections
CD4+ T-Cell Count: AIDS
<200 cell/mm³
- Once diagnosis of AIDS, then always have that diagnosis even if CD4+ T-cells count goes over 200.
HIV-II, class 0
Patient develops a first positive HIV test result within 6 months after a negative HIV test result. CD4+ T-cell counts are usually in the normal range and no AIDS-defining condition is present.
HIV-III, class 3
Patient has a CD4+ T-cell count of less than 200 cells/mm3 (0.2 X 109/L) or a percentage of less than 14%. Any patient, regardless of CD4+ T-cell counts or percentages who has an AIDS-defining illness. AIDS diagnosis.
HIV-II, class 1
Patient has a CD4+ T-cell count of greater than 500 cells/mm3 (0.5 X 109/L) or a percentage of 29% or greater. No AIDS-defining illnesses are present.
HIV-II, class 2
Patient has a CD4+ T-cell count between 200 and 499 cells/mm3 (0.2 to 0.499 X 109/L) or a percentage between 14% and 28%. No AIDS-defining illnesses are present.
HIV-class unknown
Patient has a confirmed HIV infection but no information regarding CD4+ T-cell counts, CD4+ T-cell percentages, and AIDS-defining illnesses is available.
transmission of HIV
- unprotected sexual intercourse with an infected partner
- vertical transmission: mother to child- in utero, during delivery, breastmilk
- injection drug use (rare: infected blood products)
highest prevalence of HIV
- Blood and Semen have highest transmission, then vaginal secretions
- anal sex is the highest risk (more than vaginal): rectal mucosa tears more easily, no natural lubrication, receiving partner at highest risk
- vaginal sex is 2nd highest risk transmission
- saliva is the 3rd highest risk transmission
- Need contact of infected body fluid to mucous membranes or non-intact skin or directly into the bloodstream
- just because you have sex with an HIV+ person does not mean that you will automatically get HIV
who is at high risk for HIV
- Gender: can be either men or women
- Sexual act: receiving partner
- Viral Load: more virus that they have (newly dx, not taking meds) have higher viral load
- Vulnerable populations: not educated about safe sex, cant afford contraception, IV drug users, incarcerated persons (people that don’t have access to good health care or education), serodiscordant
- Cultural considerations: certain cultures don’t allow contraception use, anal sex is preferred
- Elderly considerations: nursing homes have high rates of STI/STDs
safer sex practices to prevent HIV
- A latex or polyurethane condom for genital and anal intercourse
- A water-based lubricant with a latex condom
- A condom or latex barrier (dental dam) over the genitals or anus during oral-genital or oral-anal sexual contact
- Latex gloves for finger or hand contact with the vagina or rectum
HIV: Pre-exposure prophylaxis “PreP”
Used for high risk populations (the people that are currently HIV-)
- Men who have sex with men
- Heterosexually active men and women
- Injecting drug users (dirty needles)
- Serodiscordant relationships: HIV+ partner with HIV- partner
“PreP” is a pill that protects you from developing HIV (protects cells from HIV getting in “shield”), must take HIV test to prove negative before starting, then take it very regularly, retest every 6 months; taken for an extended period of time/rest of life
- example: Truvada
HIV: Postexposure prophylaxis “PEP”
- Occupational exposure: nurse gets needle stick
- Non-occupational exposure
- Sexual assault
“PEP” is an antiviral medication taken after exposure to HIV; test first, then retest; taken one time for certain regimen; not guaranteed to work but worth taking
- example: cART: combination antiretroviral therapy (cocktail of medication to hit multiple stages of HIV cycle)