RN Evy Warmbier MSN RN CNE Objectives To Identify the Basic Hematological Components To Understand the Clotting Cascade To Relate the Fibrinolytic Systems Regarding Medication Administration ID: 920994
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Slide1
Hematology
Donna O’Niell, RNEvy Warmbier, MSN, RN, CNE
Slide2Objectives
To Identify the Basic Hematological ComponentsTo Understand the Clotting CascadeTo Relate the Fibrinolytic Systems Regarding Medication AdministrationTo compare this knowledge when caring for a patient with upper GI bleed.
Slide3Three Basic Components of Hematology
The Bone Marrow
The Spleen
Slide4Hematology Basics – 1. Bone Marrow
The bone marrow makes stem cells Myeloid stem cells produce Erythrocytes (red blood cells)
Thrombocytes (platelets)
Lymphoid stem cells produce
B & T cells for the immune system
Slide5Hematology Basics – 2. Liver
The liver does many things including:Synthesis of AlbuminCoagulation factors
Removes nonfunctioning erythrocytes
Slide6Hematology Basics – 3. Spleen
The spleen Removes damaged erythrocytes from the blood
Slide7Hematological Homeostasis
Definition: The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.Example 1:
Erythropoetin
is released by the kidneys in states of hypoxemia which makes the bone marrow produce more erythrocytes to carry the oxygen to the tissue.
Example 2:
If a vessel is injured, platelets rush to the site to form a plug, then cytokines are released to stimulate the production of more platelets
Example 3:
Forming clots (the clotting cascade) & dissolving clots (thrombolytic effect)
Slide8The Clotting Cascade
See handout for Blood Coagulation Factors
Slide9The Clotting Cascade
Slide10Hematology - Platelets
Definition: Platelets are the smallest of the three major types of blood cells. The principal function is to prevent bleeding. Overview:
Normal count 150,000 - 350,000 per
microliter
of blood
8 to 10 day lifespan
10 % are consumed daily in normal body repairs
30% are stored in the spleen for injury
Starts the clotting process after injury
In ITP,
spleenomegaly
, up to 70% may be stored in the spleen
They contain proteins on their surface that allow them to stick to breaks in the blood vessel wall and also to stick to each other.
Slide11Hematology – Platelet Inhibitors
Aggrenox : (ASA with extended release)Used in patients post TIA or ischemic CVAAspirin: inhibits platelet aggregation for the life of the platelet
Can be given chewable, regular or enteric coated
Given to patients with arterial or vascular diseases such as MI, CVA, post PCI, chronic angina, & peripheral vascular diseases
Can have non-responders to the ASA if taking enteric, switch to regular
Clopidogril
: (
plavix
), 75 mg
po
daily
Give 600 mg
p.o
. with the start of PCI
Normal platelet function returns in about 4 days
10 % of patients may not respond to
plavix
, may need to switch to
ticlid
Ticlopidine
: (
ticlid
), 250 mg bid
Can cause thrombocytopenia,
neutropenia
delayed onset,
Return to normal platelet within 7 days
Slide12Hematology – Platelet Inhibitors
Eptifibatide: (intergrilin) IIb/
IIIa
inhibitor
Bolus with 180 mcg/kg IV and then 2 mcg/kg/min IV 12 to 24 hours
Lower dose by ½ in pts with
creatinine
> 2.0
Given with ASA, heparin prior to start of PCI
Give 12 to 24 hours for acute MI
Half life 2.5 hours
Abciximab
: (
reoPro
)
IIb
/
IIIa
inhibitor
Bolus with 0.25mg/kg IV,
then 0.125 mcg/kg/min for 12 hours
Can cause severe thrombocytopenia
Given with ASA and heparin prior to the start of PCI
Half life 10 min.
Slide13Anticoagulants
Warfarin
Unfractionated
Heparin
Low Molecular Weight Heparin
Slide14Anticoagulants –
Warfarin/Coumadin cont.
Action:
Inhibitor of Vitamin K which is essential to the hepatic synthesis of clotting factors II, VII, IX and X
Uses to prevent embolism in patients with:
Thrombophlebitis
Porcine heart valve
Mechanical heart valve
Atrial
fibrillation
Myocardial infarction
Slide15Anticoagulants –
Warfarin/Coumadin cont. Contra-indications
Recent stroke, active internal bleeding
Recent
neuro
and eye or major surgery
Severe hypertension
Renal or hepatic insufficiency
Thrombocytopenia
Pregnancy
Intracranial tumor
Pericarditis
Recent spinal puncture
Dose to increase
prothrombin
time (PT)
Normal PT is 11 – 14 seconds
Desired dose PT 1.5 to 2.5 times normal
or INR = 2 - 3
Slide16Anticoagulants –
Warfarin/Coumadin cont. Effects are Potentiated by
Drugs such as:
ASA,
Quinidine
, Sulfonamides, Chloral hydrate,
Amiodarone
,
Chloramphenicol
, antibiotics,
thrombolytics
Check the PDR
Physical conditions such as:
Carcinoma,
Vit
K deficiency, Scurvy, CHF, infectious hepatitis
Effects are Decreased by
Drugs such as:
Antacids, estrogen, oral contraceptives, thiazide diuretics, barbiturates, corticosteroids
Physical conditions such as:
Hypothyroidism, diabetes mellitus
Slide17Anticoagulants –
Warfarin/Coumadin cont. Teach Patient
Periodic testing
2% of patients/year on Coumadin have GI bleeds
Have INR checked every 4 – 6 weeks
Report excessive anticoagulation
Severe nosebleed, headache, black/bloody stools, blood in urine, coughing up blood, easy bruising
Keep diet constant
Avoid foods high in vitamin K
Slide18Anticoagulants – Unfractionated
Heparin
Make sure you have the correct concentration!
Slide19Anticoagulants – Unfractionated
Heparin
Action
Inhibits conversion of
prothrombin
to thrombin
Inhibits
formed thrombin
Inhibits
the aggregation of platelets
Uses:
To treat or prevent
thromboembolism
for patients with:
ACS,
atrial
fibrillation, PE, DVT
To prevent
thromboembolism
in patients undergoing:
Reperfusion
treatment with
fibrinolytics
PCI or CABG
To diagnose and/or treat DIC
Slide20Anticoagulants – Unfractionated
Heparin
Monitor
aPTT
:
Obtain baseline
aPTT
, normally it is 25 to 35 seconds
Dose is adjusted to increase the
aPTT
to 1.5 to 2 times the control (to 45 to 70 seconds)
Recheck
aPTT
q6 hours
IV Bolus
60 – 80 U/Kg (maximum is 100 units/
kg) or 5,000 U total
IV
Infusion
12
– 18 U / Kg / hr or 1250 U/hr
See PDR for
increase and decrease in infusion rate
Antidote:
Protamine
sulfate IV
1 mg
protamine
to neutralize 100 units heparin bolus
½ mg
protamine
to neutralize 100 units heparin
gtts
Slide21Anticoagulants – Low Molecular Weight Heparin
Description:
Fractionated heparin that is 1/3 the size
Inhibits activated clotting factor X
Advantage:
More predictable anti-thrombin response and longer half-life
Does not affect
aPTT
. Lab monitoring not required
Less risk of HIT
More cost effective
Decrease dose for elderly
Disadvantages:
Reversal is difficult
Protamine
sulfate is not the best agent.
Heparinase
may be effective
Slide22Anticoagulants – Low Molecular Weight Heparin
For DVTEnoxaparin
(
Lovenox
): 1 mg/kg SC bid
+ ASA 325 mg / d x 2 – 8 days.
Is the only FDA approved LMWH for DVT prophylaxis
For Unstable Angina / non Q wave AMI
Enoxaparin
1 mg/kg SC q 12 hrs
+ ASA 325 mg / d x 2 – 8 days
Or
Dalteparin
(
fragmin
): 120 IU / kg, not to exceed 10,000 IU Q 12 hr + ASA 75 – 165 mg / day for 5 – 8 days
Treat VTE
Lovenox
1
jmg
/ kg SC q 12 h; or 1l5 mg / kg SC daily.
Not to
exceet
180 mg
Antidote:
reversal is difficult as these meds have a long half-life
Protamine
1 mg IV per 1 mg of
lovenox
given will partially reverse, may add FFP
Slide23Heparin-Induced Thrombocytopenia
HIT Type I:Most common, seen in up to 30 % of patients receiving heparin therapy
Seen within a few days after heparin started
Platelet depletion is moderate, 100,000/mm
3
Condition is transient, DC heparin not required
HIT Type 2:
Immune-mediated response
Seen in 3 to 5% of patients receiving
unfractionated
heparin
Also seen after exposure to LMWH
Severe thrombocytopenia, platelets down to 50,000/mm
3
Onset 5 to 14 days after exposure to heparin or within minutes after
rexposure
Mortality rate as high as 30%
Slide24Heparin-Induced Thrombocytopenia
Pathophysiology
Formation of platelet antibody complexes (allergic reaction) which release factor 4 (PF4).
Activated platelet complexes stimulates the release of thrombin and therefore forms platelet clumps
Patients are at a greater risk of developing thrombosis rather than bleeding
. Leads to vessel occlusion ->
stroke, AMI, limb amputation, and even death.
Signs and Symptoms
Relates to where the vessel is occluded ->Cardiac, vascular, pulmonary, renal, gastrointestinal, neurologic
Nursing Management
Discontinue all heparin or
heparinized
products
Drugs:
Lepirudin
&
Argatroban
Educate patient to avoid another Heparin reaction
Slide25The
Fibrinolytic SystemFibrin degradation products
Fibrinogen
Fibrin-clot
Plasmin
Plasminogen
T-PA
F
XIIa
HMWK
Kallikrein
Urokinase
Streptokinase
Clotting Cascade
Biomaterials Research
Manfred Mann
Slide26Slide27Bibliography/References
Thelan, Critical Care Nursing, 6th EditionLippincott Williams & Wilkins, Critical Care Challenges, __________ , High Acuity Nursing, _____
http://www.hematology.org/education/teach_case/
http://emedicine.medscape.com/hematology
www.manfred.maitz-online.de