venous thromboembolism Flashcards
hemostasis
regulated process of preserving vascular integrity by balancing clotting formation and excessive bleeding
regular process of hemostasis
activated by injury to blood vessel
hemostatic system seals off injury through platelet plug and fibrin formation
allows injured endothelium to heal
hypercoagulability
more risk for clotting
multiple coagulation factors
extra blood clot forming - thrombus can obstruct blood vessels and interfere with blood flow
coagulation cascade
terminal steps (each step is dependent on one before)
activation of factor x
conversion of prothrombin to thrombin
conversion of fibrinogen to fibrin
intrinsic side
look at this to measure PTT
extrinsic side
look at this to measure PT
vasoconstriction
reduces blood loss
platelet plug
platelets form onto injury along with fibrin plug
clotting cascade
clotting factors are activated
virchow’s triad
endothelial damage, hypercoagulability, stasis
endothelial dysfunction can be caused by
smoking, HTN
endothelial damage can be caused by
surgery, catheter (PICC lines), trauma
hypercoagulability can be caused by
cancer, chemo, pregnancy, obesity, HIT, oral contraceptives, hormone replacement
stasis can be caused by
immobility, polycythemia (excess platelets)
DVT
impede venous return, create inflammatory response, risk for pulmonary embolism
acute DVT
redness unilateral swelling uncomfortable difficulty with walking half of DVTs are asymptomatic
clinical manifestations of DVT depend on
location and size of thrombus
clinical manifestations of DVT
edema warmth tenderness to pain functional impairment may be asymptomatic signs and symptoms of inflammation (fever, malaise, increase in WBC)
D-dimer level
positive is greater than 500
serum blood test that shows breakdown of fibrin in the blood
compression ultrasonography
shows that a clot exists, pushing down on veins
shows restriction of blood flow
complications of DVT
clot extension (more platelets joining clot) pulmonary embolism postphlebitic syndrome venous valve damage recurrent DVT formation
goal of managing DVT
prevent further thrombosis and complications
strategies to manage DVT
anticoagulant therapy
patient education
endovascular management
symptom management
DVT nursing management
anticoagulant therapy monitor complications provide comfort graduated compression stockings positioning and activity
graduated compression stockings
decrease swelling prevent venous insufficiency wear them all day remove at night check pulses pain will decrease can apply warm, moist heat
positioning and activity
have legs up and do not want them to cross legs (avoid severe flexion)
initial anticoagulation (first 10 days)
subcutaneous low molecular weight heparin (enoxaparin)
Xa inhibitors
oral factor Xa inhibitors
unfractionated heparin
long term anticoagulation (10 days-3 months)
direct factor Xa inhibitors
thrombin inhibitors
vitamin K antagonists (warfarin)
nursing considerations for AC therapy
safety lab monitoring close observation for bleeding patient teaching med safety
lab monitoring for heparin
monitor PTT (1.5-2.5 x regular number) has a short half-life
lab monitoring for warfarin
monitor PT (64 secs) and INR (2-3)
above 3 - very high bleeding times
below 2 - slow and at risk for clot
heparin antidote
protamine sulfate
warfarin antidote
if INR is 7
vitamin K
side effects of heparin
heparin-induced thrombocytopenia (HIT)
monitor platelets, baseline CBC before administration
if platelets are low, notify provider and stop infusion - start anticoagulant
action of heparin/enoxaparin
inhibits thrombus and clot production by blocking the conversion of prothrombin to thrombin and fibrinogen t fibrin (inhibit formation of additional clots)
adverse effects of heparin
loss of hair, bruising, chills, fever, osteoporosis, suppression of renal function (long term use), thrombocytopenia, hyperkalemia
teaching points that are priority for a patient receiving AC therapy
brush teeth gently with soft bristle brush
wear or carry med alert notification
use an electric razor when shaving
obtain follow-up lab work regularly as ordered
if a patient is on a heparin infusion and exhibits bleeding, nursing interventions include
stop the heparin infusion (first)
obtain coagulation labs
monitor BP hourly
meds that can affect the action of anticoagulants
vitamins cold meds antibiotics aspirin mineral oil anti-inflammatory agents
report symptoms to health provider
faintness dizziness increased weakness severe headaches abdominal pain reddish/brownish urine any bleeding bruises/nosebleeds red or black bowel movements rash
thrombectomy
getting rid of thrombus by inserting catheter
vena cava filter
done for patients at high risk for clotting but not appropriate for AC therapy
seen in orthopedic surgeries
threaded through femoral vein into vena cava
DVT prevention
prophylactic meds (heparin) graduated compression stockings pneumatic compression devices positioning - avoid flexion hydration activity and passive limb exercises ambulation avoid sitting/standing for long time
pulmonary embolism
thrombus that originated in venous system and turns into emboli, breaks off, and gets into the right side of the heart
pathophysiology of PE
thrombus obstructing pulmonary artery
increase in alveolar dead space
increase in pulmonary vascular resistance and pulmonary artery pressure
may lead to ischemic necrosis
perfusion without ventilation
obstruction within airway
normal blood flow
blood is going to be not oxygenated
ventilation without perfusion
blocking flow of blood
air is going to lungs but blood is not getting to alveoli
clinical manifestations of PE
dyspnea and tachypnea chest pain (pleuritic pain) anxiety and apprehension (impending sense of doom) fever tachycardia hemopytsis cough
symptoms will depend on ____ of PE and _____ of obstruction
size; location
complications of PE
hemodynamic instability (syncope, weak rapid breath)
shock
death
vitals for PE
tachypnea, tachycardia, low BP
ABGs for PE
can start off with respiratory acidosis and progress to alkalosis
EKG for PE
inverted T-waves
no presence of ST elevation
chest XR for PE
infiltrates present
V/Q scan for PE
mismatch between perfusion and ventilation
pulmonary angiography for PE
gold standard
direct visualization of obstructed artery
diagnostic tests that are related to PE
d-dimer assay
V/Q scan
spiral CT
pulmonary angiography
objectives of managing PE
restore pulmonary perfusion
prevent further DVT/PE
protect lungs from thromboemboli
management strategies for PE
AC therapy symptom management surgical management Pt education thrombolytic therapy
AC vs. thrombolytic therapy
AC therapy used for non-massive PE
thrombolytic therapy used for massive PE
general management for PE
O2 therapy managing pain relieving anxiety monitor complications AC or thrombolytic therapy patients should have IV access (meds and fluids)
action of urokinase
activating plasminogen to plasmin which breaks down fibrin threads in a clot to dissolve a formed clot
indications of urokinase
acute MI, massive pulmonary emboli, ischemic stroke
pharmacokinetics of urokinase
drug must be injected and are cleared from the body after liver metabolism
pregnancy and lactation
prior to administration of urokinase
monitor coagulation status (CBC)
after administration of urokinase
monitor bleeding and LOC
contraindications of urokinase
allergy and bleeding disorders
adverse effects of urokinase
bleeding (do invasive procedures beforehand)
cardiac dysrhythmias
hypotension
hypersensitivity (rash, flushing, bronchospasm, anaphylactic reaction)
embolectomy
catheter through vena cava to pull out clot; not common because PE can happen too quickly
administration of enoxaparin (LMWH)
IV and subcutaneous (can take it home)
administration of heparin
IV and subcutaneous
signs of enoxaparin overdose
hemorrhagic complications
signs of heparin overdose
bleeding, nosebleeds, hematuria, tarry stools, bruising, petechial formations
signs of warfarin overdose
blood in stools/urine, excessive bruising, persistent oozing from superficial injuries, excessive menstrual bleeding, melena, petechiae
