Unit 2: Pulmonary Embolism Flashcards
Pulmonary embolism (PE)
obstruction of one or more of the branches of the pulmonary artery by particulate matter that has a origin elsewhere in the body
Pulmonary Embolisms (PE) are caused by?
- thrombus or piece of tumor
- amniotic fluid
- air
- fat
Greatest Risk Factor for Pulmonary Embolism (PE)
presence of a deep vein thrombosis (DVT)
What is the major predisposing factor for the development of a DVT?
Virchow’s Triad
- venous stasis
- vessel wall damage
- hypercoagulability
Virchow’s Triad
predisposing factors for development of a DVT
- venous stasis
- vessel wall damage
- hypercoagulability
Most common cause of DVT
immobility
Other Risk Factors for Development of a DVT
- obesity
- smoking
- chronic heart disease
- fracture (hip or leg)
- hip or knee replacement
- major surgery
- major trauma
- spinal cord injury
- hx of previous thromboembolism
- malignancy
Pathophysiology of a Pulmonary Embolism (PE)
- when a blood clot or other particulate matter travels to the lungs, it lodges into the pulmonary artery and blocks blood flow
- obstruction results in an impaired ventilation-to-perfusion ratio (V/Q); described as decreased or blocked flow or perfusion to functioning alveoli
Ventilation-Perfusion mismatch (V/Q mismatch)
a decreased blood flow to functioning alveoli or areas of the lung where gas exchange can take place if perfusion is adequate
Clinical Manifestations of PE
- sudden onset of intense dyspnea, pleuritic chest pain, and tachypnea
- PE suspected in any post-op patient
- Hypotensive and Tachycardic b/c of decreased cardiac output (CO)
- Cerebral perfusion my become compromise; anxious, restless, and/or confused
Common Signs and Symptoms of PE
- dyspnea
- accessory muscle use
- pleuritic chest pain
- tachycardia
- tachypnea
- crackles upon auscultation
- cough
- hemoptysis
- unilateral lower extremity edema d/t presence of a DVT; pain in extremity, w/ redness and warmth
Imaging Studies for PE
- Electrocardiogram (ECG)
- Chest x-ray
- CT of the chest (w/ contrast)
- Ventilation-perfusion scan (V/Q Scan)
- Pulmonary Angiography
- Once patient w/ acute PE is stable, lower extremity venous ultrasound is conducted to determine presence and extent of any DVT
What is the initial study for any patient present w/ chest pain?
Electrocardiogram (ECG/EKG)
- to r/o MI
- ischemic changes may be seen (ST changes [depression])
Imaging: Chest X-ray
to r/o other causes of respiratory distress
Ventilation-perfusion scan (V/Q scan)
- utilized if CT scan not available
- can identify areas of the lungs that are ventilated but not perfusing effectively; indication of obstruction of the pulmonary vasculature
- “high probability” = perfusion mismatch
Most Definitive Test for PE
Pulmonary Angiography
Pulmonary Angiography
most definitive test for PE
- allows for visualization of the pulmonary vasculature; detects any obstruction
- only done if other studies not conclusive and patient is stable
Laboratory Studies for PE
- Plasma D-dimer
- ABGs
- Cardiac studies (BNP)
Plasma D-Dimer
level increases as the body removes clots through lysis as part of the normal clot-removal process
- D-dimer is the fibrin left behind from that lysis
- negative D-dimer r/o possibility of a clot
- positive D-dimer = presence of clot but requires further testing
ABGs
- hypoxemia (PaO2 < 80 mmHg)
- respiratory alkalosis (PaCO2 < 35)
- may later show metabolic acidosis d/t hypoxemia b/c body switches to anaerobic metabolism in face of hypoxemia
Laboratory Tests: Cardiac (BNP)
- BNP may be elevated d/t strain on the ventricles brought on by PE
- BNP is released by overstretched ventricles under physiological stress
- BNP > 100 = Heart Failure (HF)
Normal BNP (Brain Natriuretic Peptide)
less than 100
-BNP is released by overstretched ventricles under physiological stress
Treatments for a Pulmonary Embolism (PE)
-primarily anticoagulation
>Nonsymptomatic:
-Oral factor Xa inhibitor; require no lab monitoring for med; no hospitalization
>Symptomatic:
-w/ any type of PE: blood clot, air, fat, b/c blood clots will adhere to any of those substances making them larger and able to obstruct more blood flow
-IV Heparin w/ a bolus followed by a continuous drip
Anticoagulation
- does not reduce clots, but keeps clot from getting larger
- helps to reduce the formation of other clots
Heparin Therapy
-monitored through aPTT
-prior to therapy; a aPTT is drawn and repeated q 4 to 6 hours to monitor therapy
-therapeutic goal: 1.5 to 2.5 times the normal value or 40 to 90 seconds
-if aPTT is above therapeutic level, rate of infusion is reduced
>Very high aPTT = infusion may be held before restarting to a lower rate
-If aPTT below level, an additional heparin bolus, along w/ increased rate of infusion
-once aPTT in therapeutic range for 2 consecutive iterations, it is evaluated q 12 or 24 hours
-Protamine Sulfate reversal for heparin; be readily available if active bleeding occurs
What Lab value is looked at when starting heparin therapy?
aPTT
Anticoagulation after discharge
> Warfarin (Coumadin)
- monitored through INR
- Goal: INR of 2.0 to 3.0
- takes 3 to 5 days to reach therapeutic level; that’s why heparin and warfarin used concurrently
Thrombolytic Therapy: Alteplase
- if hemodynamically compromised
- Alteplase: responsible for lysis or removal of the clot from pulmonary artery
- risk of bleeding
- risk of cerebral hemorrhage in elderly
- IV heparin usually D/C during Alteplase infusion, then restarted after infusion complete
Contraindications to Thrombolytic Therapy
> Absolute:
- hx of hemorrhagic stroke
- active intracranial neoplasm
- recent surgery
- recent trauma (less than or equal to 2 months)
- active or recent internal bleeding
> Relative:
- severe hypertension (SBP > 200, DBP >110)
- non-hemorrhagic stroke (within 2 months)
- surgery in past 10 days
- thrombocytopenia (platelets less than 100,000)
- hx of bleeding tendencies
Catheter-directed Thrombolysis
- for patients hemodynamically unstable
- uses low-dose hourly infusions of tissue plasminogen activator (tPA) or urokinase
- administration of the medication directly to the clot at the site; lysis of the clot and decreases risk of bleeding complications
Intravenous Isotonic Fluid
- decreases viscosity of blood
- caution taken to prevent fluid overload
Surgical Management
- Embolectomy
- Inferior Vena Cava Filters (IVC)
Embolectomy
physical removal of a clot
-catheter or surgical
Inferior Vena Cava Filters (IVC)
placed to prevent recurrent PE
- allows for blood passage
- designed to trap any further emboli originating in lower extremities
Indications for a Inferior Vena Cava Filter (IVC)
- active bleeding that disqualifies anticoagulation therapy
- recurrent PE despite adequate anticoagulation therapy
- evidence that hemodynamic or respiratory dysfunction is severe enough that another PE could be fatal
Complications of the Inferior Vena Cava Filter (IVC)
- filter migration
- erosion of the vena cava wall
- obstruction d/t filter thrombosis
- procedural complications
Nursing Management: Assessment and Analysis
- clinical manifestations are non-specific
- sudden onset of pleuritic chest pain, dyspnea, and tachypnea
- If pulmonary vascular resistance (PVR) is elevated, JVD may be seen
- w/ a massive PE, preload to the left side of the heart may be reduced which leads to decreased CO and hypotension
- sudden change in mental status if cerebral perfusion pressure is compromised
- anxious or express feelings of impending doom
Nursing Diagnoses for PE
- Impaired gas exchange r/t interruption of pulmonary blood flow
- Ineffective breathing pattern: Tachypnea r/t pain and hypoxemia
- Decreased CO r/t increased PVR
- Risk for bleeding r/t anticoagulant/ thrombolytic therapy
Nursing Assessments
- Airway
- Oxygenation
- Frequent vital signs
- Chest Pain
- Lab Values (ABG, Lactic Acid, Coagulation)
- Urine output
Assessments: Airway
is breathing effective to maintain oxygenation?
- pt breathing comfortably or in respiratory distress?
- mechanical ventilation may be required
Assessment: Oxygenation
-pulse oximetry reading decreases from baseline as a result of increased dead-space ventilation; blood is not properly oxygenated in the lungs
Assessment: Frequent Vital Signs
- pulse increases b/c of hypoxemia
- BP decreases in cases of massive PE b/c of decreased left heart preload
- tachypnea d/t decreased oxygenation and pain
- fever b/c of inflammatory response
Assessment: Chest Pain
-sudden onset (pleuritic) pain w/ dyspnea and tachycardia = first sign of acute PE
>resulting from release of inflammatory markers
Lab Values: Arterial Blood Gases (ABGs) [Onset]
- tachypnea causes respiratory alkalosis
- PaO2 reduced b/c increased dead-space ventilation
Lab Values: Arterial Blood Gases (ABGs) [as disease progresses]
-metabolic acidosis results from hypoxia and subsequent transition to anaerobic metabolism
Lab Values: Lactic Acid Level
increase confirms anaerobic metabolism
Lab Values: Coagulation studies
- aPTT monitored if on Heparin
- PT/INR if on warfarin
Assessment: Urine Output
less than 0.5 mL/kg/hr = early sign of shock
Nursing Actions
- Elevate HOB
- Administer IV fluids
- Anticoagulation Meds
- Thrombolytic Meds
- Inotropic agents
- Norepinephrine or Vasopressin as ordered
- Bleeding Precautions
- Be prepared for Intubation and resuscitation
Actions: Elevate HOB
- allows diaphragm to drop
- facilitates less work of breathing and better oxygenation
Actions: Administer IV fluids
- decrease viscosity of blood
- caution used in cases of right ventricular overload
Actions: Anticoagulation Meds
- Heparin infusions, warfarin, and factor Xa inhibitors limit growth of PE and DVT
- decreases formation of new clots
Actions: Thrombolytic Meds
- degrades the clot
- if not contraindicated, used when hemodynamically compromised
Actions: Inotropic Agents
increased cardiac contractility to augment cardiac output if patient is hemodynamically unstable
Actions: Norepinephrine or Vasopressin as ordered
vasoconstrictive meds given, if necessary, to maintain systolic BP of at least 80 mmHg
Actions: Bleeding Precautions
- use of anticoagulants and/or thrombolytics can result in bleeding
- minimize venipunctures
- watch for blood in urine, stool, sputum
- watch for unusual bruising
Actions: Be prepared for intubation and resuscitation
massive PE may result in cardiogenic shock and sudden death
Nurse Teachings
- Disease Process/ lifestyle Modifications
- Medications
- Bleeding Precautions
- Diet
- S/S of recurrent PE/DVT
Teachings: Disease Process/Lifestyle Modifications
- understand risks of PE
- how to avoid future occurrences
- smoking cessation
> Exercise Regimen:
-aerobic exercise strengthens heart + cardiovascular system, improves venous return to the heart, assists in loss of weight
> Cardiac-prudent diet that minimizes saturated fats:
-heart-healthy diet to reduce damage to vasculature
> Adequate fluid intake:
-8oz glasses of water 8x spread across the day; maintains hydration; decreases blood viscosity
> Medications: teach mechanism of action of anticoagulants + thrombolytics; follow-up lab samples drawn if on warfarin (PT/INR) to determine effective dosing of outpatient anticoagulant
Teaching For Bleeding Precautions
- use of electric razor
- soft toothbrush
- no flossing
- avoid activities w/ a risk of bleeding
Teaching: Diet
limit foods high in vitamin K; interfere w/ efficacy of warfarin
Teaching: Signs of recurrent PE/DVT
- unilateral lower extremity edema and pain, w/ redness and warmth d/t presence of DVT
- pleuritic chest pain and dyspnea = recurrent PE
Evaluating Care Outcomes
- if had PE, there is increased incidence of recurrent PE
- adhering to medication regimen
- improving diet
- beginning exercise program
- staying adequately hydrated
- quit smoking
Connection Check: After oxygen has been administered the next PRIORITY intervention the nurse would initiate for a patient with a pulmonary embolus is the administration of which of these therapies? A. Normal Saline IV Fluid B. IV Heparin C. Platelet administration D. Antibiotics for inflammatory fever
B. IV Heparin
