Transcript Acute Respiratory Distress Syndrome

PULMONARY EMBOLISM
Dr. Abdul-Monim Batiha, RN, MSN,
PhD
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Pulmonary embolism (PE)
• Pulmonary embolism (PE) refers
to the obstruction of the
pulmonary artery or one of its
branches by a thrombus (or
thrombi)
that
originates
somewhere in the venous system
or in the right side of the heart.
• Most commonly, PE is due to a
blood clot or thrombus.
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• However, there are other types of
emboli: air, fat, amniotic fluid,
and septic (from bacterial
invasion of the thrombus).
• It is estimated that more than
half a million people develop PE
yearly, resulting in more than
50,000 deaths.
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• PE is a common disorder and
often is associated with trauma,
surgery (orthopedic, major
abdominal, pelvic, gynecologic),
pregnancy, heart failure, age
older than 50 years,
hypercoagulable states, and
prolonged immobility. It also may
occur in an apparently healthy
person
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Risk Factors for Thromboembolism
Hereditary Thrombophilias
■ Protein C deficiency
■ Protein S deficiency
■ Antithrombin III deficiency
■ Factor V Leiden mutation
■ Prothrombin 20210 G–A variation
■ Hyperhomocysteinemia
Acquired Surgical Predisposition
■ Major thoracic or abdominal surgery
requiring general anesthesia and
lasting >30 minutes
■ Hip arthroplasty
■ Knee arthroplasty
■ Knee arthroscopy
■ Hip fracture
■ Major trauma
■ Open prostatectomy
■ Spinal cord injury
■ Neurosurgical procedures
Acquired Medical
Predisposition
■ Prior venous thromboembolism
■ Age >40 years
■ Malignant neoplasia
■ Congestive heart failure
■ Cerebrovascular accident
■ Nephrotic syndrome
■ Estrogen therapy
■ Pregnancy and the postpartum
period
■ Obesity
■ Prolonged immobilization
■ Antiphospholipid antibody
syndrome
■ Lupus anticoagulant
■ Inflammatory bowel disease
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Pathophysiology
• When a thrombus completely or partially
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obstructs a pulmonary artery or its branches, the
alveolar dead space is increased.
The area, although continuing to be ventilated,
receives little or no blood flow.
Thus, gas exchange is impaired or absent in this
area.
In addition, various substances are released
from the clot and surrounding area, causing
regional blood vessels and bronchioles to
constrict.
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Pathophysiology
• This causes an increase in pulmonary
vascular resistance.
• This reaction compounds the ventilation–
perfusion imbalance.
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Pathophysiology
• The hemodynamic consequences are
increased pulmonary vascular resistance
from the regional vasoconstriction and
reduced size of the pulmonary vascular
bed.
• In patients with no preexisting
cardiopulmonary disease, obstruction of
less than 20% of the pulmonary vascular
bed produces compensatory events that
minimize adverse hemodynamic
consequences.
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Pathophysiology
• When the degree of pulmonary vascular
obstruction exceeds 30% to 40%,
increases in pulmonary artery pressure
occur, followed by modest increases in
right atrial pressure.
• When the work requirements of the right
ventricle exceed its capacity (the degree
of pulmonary artery obstruction exceeds
50% to 60% )right ventricular failure
occurs, leading to a decrease in cardiac
output followed by a decrease in systemic
blood pressure and the development of
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shock.
Signs and Symptoms of Pulmonary
Embolism
Small to Moderate
Embolus
Dyspnea
Tachypnea
Tachycardia
Chest pain
Mild fever
Hypoxemia
Apprehension
Cough
Diaphoresis
Decreased breath sounds over
affected area
■ Rales
■ Wheezing
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Massive Embolus
A more pronounced manifestation
of the above signs and
symptoms, plus the following:
■ Cyanosis
■ Restlessness
■ Anxiety
■ Confusion
■ Hypotension
■ Cool, clammy skin
■ Decreased urinary output
■ Pleuritic chest pain: associated
with pulmonary infarction
■ Hemoptysis: associated with
pulmonary infarction
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Signs of Pulmonary Embolism in Intensive Care
Patients
■ Worsening hypoxemia in a patient on spontaneous
ventilation
■ Worsening hypoxemia and hypercapnia in a sedate
patient on controlled mechanical ventilation
■ Worsening dyspnea, hypoxemia, and a reduction in
PaCO2 in a patient with chronic lung disease and known
carbon dioxide retention
■ Unexplained fever
■ Sudden elevation in pulmonary artery pressure or central
venous pressure in a hemodynamically monitored
patient
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Diagnostic Evaluation
• ABG levels: decreased Pao2 is usually
found, due to perfusion abnormality of the
lung.
• Chest X-ray: normal or possible wedgeshaped infiltrate.
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• lung scans: perfusion scan investigates
regional blood flow to determine presence
of perfusion defects; ventilation scan may
be done in patient with large perfusion
defects.
• Pulmonary angiogram (most definitive):
emboli seen as filling defects.
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Management
• Heparin and thrombolytic agents are used
to treat PE.
• Patients with DVT or pulmonary embolism
should be treated with unfractionated
intravenous heparin or adjusted-dose
subcutaneous heparin.
• (For subcutaneous treatment with
unfractionated heparin, give 250 U/kg
every 12 hours to obtain an activated
partial thromboplastin time [aPTT] with
therapeutic range at 6 to 8 hours.)
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Management
• Low–molecular-weight heparin (LMWH)
can be substituted for unfractionated
heparin in patients with DVT and in stable
patients with pulmonary embolism.
• Treatment with heparin or LMWH should
continue for at least 5 days, overlapped
with oral anticoagulation for at least 4 to 5
days
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• The recommended length of
anticoagulation therapy varies,
depending on the patient’s age,
comorbidities, and the likelihood of
recurrence of pulmonary embolism
or DVT.
• In most patients, anticoagulation
therapy with warfarin should be
continued for 3 to 6 months
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• Thrombolytic therapy is only
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recommended for patients with acute
massive pulmonary mbolism who are
hemodynamically unstable and not prone
to bleeding.
Intracranial disease, recent surgery,
trauma, and hemorrhagic disease are
contraindications to thrombolytic therapy
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• Placement of an inferior vena cava filter is
recommended to prevent pulmonary
embolism in patients with
contraindications to heparin therapy.
• And also recommended in patients with
recurring thromboembolism despite
adequate anticoagulation, chronic
recurrent embolism and pulmonary
hypertension, and concurrent surgical
pulmonary embolectomy or pulmonary
endarterectomy procedures
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FIGURE 11-2 Insertion of umbrella filter in inferior vena cava to prevent
pulmonary embolism. Filter (compressed within an applicator catheter) is
inserted through an incision in the right internal jugular vein. The applicator is
withdrawn when the filter fixes itself to the wall of the inferior vena cava after
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ejection from the applicator.
Prevention
• Prevention of venous thromboembolism is
essential to decreasing the morbidity and
mortality associated with pulmonary
embolism.
• Prophylactic measures are based on the
patient’s specific risk factors.
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Nursing Diagnoses
• Ineffective Breathing Pattern related to
acute increase in alveolar dead airspace
and possible changes in lung mechanics
from embolism
• Ineffective Tissue Perfusion (Pulmonary)
related to decreased blood circulation
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• Acute Pain (pleuritic) related to
congestion, possible pleural effusion,
possible lung infarction
• Anxiety related to dyspnea, pain, and
seriousness of condition
• Risk for Injury related to altered
hemodynamic factors and anticoagulant
therapy
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Nursing Interventions
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Correcting Breathing
Pattern
• Assess for hypoxia, headache,
restlessness, apprehension, pallor,
cyanosis, behavioral changes.
• Monitor vital signs, ECG, oximetry, and
ABG levels for adequacy of oxygenation.
• Monitor patient's response to I.V.
fluids/vasopressors.
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• Monitor oxygen therapy used to relieve
hypoxemia.
• Prepare patient for assisted ventilation
when hypoxemia is due to local areas of
pneumoconstriction and abnormalities of
V/Q ratios.
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Improving Tissue Perfusion
• Closely monitor for shock, decreasing
blood pressure, tachycardia, cool, clammy
skin.
• Monitor prescribed medications given to
preserve right ventricular filling pressure
and increase blood pressure.
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• Maintain patient on bed rest to reduce
oxygen demands and risk of bleeding.
• Monitor urinary output hourly, because
there may be reduced renal perfusion and
decreased glomerular filtration.
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Relieving Pain
• Watch patient for signs of discomfort and
pain.
• Ascertain if pain worsens with deep
breathing and coughing; auscultate for
friction rub.
• Give prescribed morphine (Duramorph),
and monitor for pain relief and signs of
respiratory depression.
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• Position with head of bed slightly elevated
(unless contraindicated by shock) and with
chest splinted for deep breathing and
coughing.
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• Evaluate patient for signs of hypoxia
thoroughly when anxiety, restlessness,
and agitation of new onset are noted,
before administering as needed sedatives.
Consider physician evaluation when these
signs are present, especially if
accompanied by cyanotic nail beds,
circumoral pallor, and increased
respiratory rate.
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Reducing Anxiety
• Correct dyspnea and relieve physical
discomfort.
• Explain diagnostic procedures and the
patient's role; correct misconceptions.
• Listen to the patient's concerns; attentive
listening relieves anxiety and reduces
emotional distress.
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• Speak calmly and slowly.
• Do everything possible to enhance the
patient's sense of control.
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Evaluation: Expected Outcomes
• Verbalizes less shortness of breath
• Vital signs stable, adequate urinary output
• Reports freedom from pain
• Appears more relaxed; sleeping at long
intervals
• Progresses without complications
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Good Luck
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