PULMONARY EMBOLISM

Question 1

what is the etiology of PE ?

Answer 1

Deep vein thrombosis - most commonly iliac vein

fat embolism -associated with closed long bone fractures

air embolism

Amniotic fluid embolism

Question 2

risk factors for pulmonary embolism ?

Answer 2

Malignancy; myeloproliferative disorder; antiphospholipid syndrome

Surgery—especially pelvic and lower limb (much lower if prophylaxis used)

Immobility; active inflammation (eg infection, IBD)

Pregnancy; combined OCP; HRT.

Previous thromboembolism and inherited thrombophilia

Question 3

clinical features of pulmonary embolism?

Answer 3

fat embolism
Manifests with a classic triad of dyspnea, neurological deficits, and a petechial rash

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usually

Acute onset of symptoms

!!!! Dyspnea and tachypnea !!!

!!!!! Sudden pleuritic chest pain (∼ 50% of cases), worse with inspiration !!!!!

!!!! hemoptysis !!!!

Cough

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heart symptoms

Tachycardia (∼ 25% of cases)

Possibly split second heart sound audible in some cases

gallop rhythm

loud P2

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hypotension

Jugular venous distension - Right ventricular pressure overload

Kussmaul sign (in the event of a massive pulmonary embolism)

Question 4

clinical features of DVT?

Answer 4

unilaterally painful leg swelling

Question 5

Features of massive PE

Answer 5

syncope and obstructive shock with circulatory collapse (e.g., due to a saddle thrombus)

Question 6

what test is done to figure out the probability of PE ?

Answer 6

Wells criteria

Clinical symptoms of DVT - 3pts

PE more likely than other diagnoses - 3pts

Previous PE/DVT - 1.5pts

Tachycardia (Heart rate > 100/min) - 1.5pts

Surgery or immobilization in the past 4 weeks - 1.5 pmts

Hemoptysis - 1pts

Malignancy - 1pts

Question 7

what is the interpretation of wells score ?

Answer 7

Modified Wells score (clinical probability)

Total score ≤ 4: PE unlikely (8%)

Total score > 4: PE likely (34%)

Question 8

what is the diagnostic approach of PE?

Answer 8

Assess for hemodynamic stability.

Stable patients: systolic BP > 90 mm Hg

Unstable patients: systolic BP < 90 mm Hg for > 15 minutes, evidence of shock,
or BP drop > 40 mm Hg for > 15 minutes

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assess pretest for PE - wells score

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Lab studies - D- dimer
Indication: pretest probability of PE is either low or intermediate

D-dimer ≥ 500 ng/mL: CTPA or V/Q scan
A positive D-dimer is nonspecific, since it may be elevated in any situation where there is increased fibrinolysis.

D-dimer < 500 ng/mL: PE is unlikely; consider other causes of symptoms
Normal D-dimer values can usually rule out PE or DVT in patients

Unstable patients and/or high probability of PE: Obtain CTPA or V/Q scan for a definitive diagnosis.

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ABG
Hypoxemia: ↓ SaO2 and PaO2 < 80 mm Hg
Respiratory alkalosis may be present : ↓ paCO2, ↑ pH

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CTPA
CT pulmonary angiography

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Ventilation/perfusion scintigraphy (V/Q scan)

• alternative to CT pulmonary angiography in patients with renal insufficiency and/or contrast allergy

Findings
Perfusion failure in the normally ventilated pulmonary area (mismatch) suggests PE.

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Echocardiography
Indication: suspected right heart strain, critically-ill patients with suspected PE

Findings
Increased right atrial pressure
Dilatation and hypokinesis of the right ventricle, McConnell sign
Venous reflux with dilation of inferior vena cava (with corresponding liver congestion seen on ultrasound of the abdomen)
Tricuspid regurgitation (tricuspid valve insufficiency)
↑ Pulmonary artery systolic pressure

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lower extremity US

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chest X ray
may show abnormalities that indicate PE, these findings alone are not sensitive or specific enough

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Pulmonary angiography

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Magnetic resonance pulmonary angiography

Question 9

contraindications of CTPA ?

Answer 9

Renal insufficiency
Contrast allergy
Pregnancy

Question 10

with ECG what are the specific findings we see in PE ?

Answer 10

!!!!! Arrhythmias: sinus tachycardia (> 100/min) , bradycardia (< 60/min) , atrial fibrillation !!!!

Signs of right heart strain :
1) SI QIII TIII-pattern
(deep s waves in lead 1 and q waves lead 3, and inverted t waves in lead 3 )

2) New right bundle branch block (incomplete or complete)
3) Right axis deviation or extreme right axis deviation
4) : P pulmonale ,

ST-segment elevation or depression,
T-wave inversions in the anterior precordial leads (V1–V4)

Question 11

when is thromboprophylaxis given due to the risk of PE ?

Answer 11

PE following surgery is far less common, but PE may occur after any period of immobility, or with no predisposing factors.

Question 12

what is the management of pulmonary embolism ?

Answer 12

initial management
A-E

1) supplemental oxygen as needed
For patients with respiratory failure: airway management and/or mechanical ve

2) hemodynamic support in patients with hypotension 
Gentle bolus (e.g., normal saline ≤ 500 mL over 15 mis or less )
Avoid volume overload -  harmful in cases of right ventricular strain
Consider vasopressors (norepinephrine  is most commonly used or DOBUTAMINE) if there is no improvement in BP AFTER FIRST TIME of following fluid 

3) Analgesics 
Avoid NSAIDs if patient receiving anticoagulation or thrombolytics
Consider one of the following: 
Morphine 
Oxycodone
=IV
WITH ANTIEMETIC - diphenhydramine

4) Assessment of bleeding risk

5) Consider empiric anticoagulation while awaiting a definitive diagnosis
Stable patients: LMWH = enoxaparin - SC
or fondaparinux - SC

Unstable patients or patients with renal insufficiency: UFH (Unfractionated heparin)- IV

6) Risk stratify the patient based on prognostic models (see risk stratification of pulmonary embolism).
7) Initiate therapy based on risk stratification and bleeding risk.

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Massive PE: thrombolytic therapy =IF HEMODYNAMICALLY STABLE
= alteplase
or embolectomy

Submassive and nonmassive PE: anticoagulation or IVC filter

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initiate long term anticoagulation

Question 13

what bleeding risk score do you use ?

Answer 13

currently there is no scoring systems with sufficient prediction outcomes for the bleeding risk from anticoagulant therapy in patients with PE.

The HAS-BLED score is sometimes used but it was designed and validated for anticoagulant therapy in patients with atrial fibrillation

Question 14

risk factors for bleeding for VTE / PE / DVT

Answer 14

Patient characteristics:
Age > 65 years
Decreased functional capacity and comorbidity
Frequent falls

Past medical history :
Prior history of bleeding
Prior history of stroke
Recent surgery

Chronic conditions :
Cancer 
Renal failure
Liver failure
Diabetes
Alcohol use disorder

Medication history :
Poor anticoagulant control
Antiplatelet therapy
NSAID use

Laboratory abnormalities :
Low platelets
Anemia

Question 15

what is the HAS-BLED score ?

Answer 15

H - hypertension (1pt)

A - abnormal liver or renal function (1/2pt)

s - stroke 1pt

b - bleeding

L - Labile INR

E - 0ver 65 years

D - drugs/alcohol (1/2 pmts)

max score - 9

0-1 =low risk of bleeding
2 = intermediate risk
3 or more = high risk of bleeding

Question 16

what is the risk stratification for PE?

Answer 16

Pulmonary Embolism Severity Index (PESI) and simplified PESI (sPESI)

The Pulmonary Embolism Severity Index stratifies the risk of mortality or adverse outcomes and is used to assist in decisions on inpatient vs. outpatient management.

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sPESI

Age
1 if > 80 years

History of cancer

Systolic blood pressure < 100 mm Hg

Heart rate ≥ 110/min

O2 saturation on room air < 90%

Heart failure

Chronic lung disease

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sPESI interpretation (30-day mortality) 
0 points: low risk (1%)
≥ 1 point: high risk (10.9%)

Question 17

type of PE based on clinical investigations

Answer 17

Normotensive
No right ventricular dysfunction
Normal cardiac biomarkers
= Nonmassive pulmonary embolism (low-risk PE)

Stable blood pressure (SBP > 90 mm Hg)
Right ventricular dysfunction or evidence of myocardial necrosis
= Submassive pulmonary embolism (intermediate-risk PE)

Persistent hypotension (shock)
Right ventricular failure
= Massive pulmonary embolism (high-risk PE)

Question 18

management of pulmonary embolism for Nonmassive and submassive PE

Answer 18

1) Assess bleeding risk

2) consider empiric parenteral anticoagulation while awaiting definitive diagnosis
(based on bleeding risk , pretest probability of PE )

3) If bleeding risk is low to moderate, start anticoagulation

patient deteriorates after the initiation of anticoagulation but has not yet developed hypotension and has a low bleeding risk - systemic thrombolysis

4) If bleeding risk is high, consider IVC filter placement.
5) Consider continuous pulse oximetry and/or continuous telemetry.
6) In select patients with very low-risk PE (e.g., sPESI = 0): Consider outpatient therapy.
7) In patients with subsegmental PE with low risk of recurrent VTE: Consider clinical surveillance only.

Question 19

long term anticoagulation for nonmassive and submassive pulmonary embolism?

Answer 19

Long-term anticoagulation (up to 3 months)

Direct oral anticoagulant
Non-vitamin K antagonist oral anticoagulant
dabigatran, rivaroxaban, and apixaban.

No initial parenteral anticoagulation required: rivaroxaban or apixaban

Initial parenteral anticoagulation required: dabigatran or edoxaban

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or

Vitamin K antagonist - warfarin , continue till target INR 2–3
: If DOAC cannot be given, VKA is preferred over LMWH.

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LMWH: preferred in cancer patients and pregnant women

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If obvious remedial cause, 3 months of anticoagulation may be enough; otherwise, continue for ≥3–6 months (long term if recurrent emboli, or underlying malignancy).

Question 20

management of Massive pulmonary embolism

Answer 20

High-risk PE (PESI class IV–V, sPESI ≥ 1

1) Evaluate need for mechanical ventilation.

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2) a crash cart at the bedside.

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3) Check for contraindications to thrombolytic therapy in massive pulmonary embolism.

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4) no absolute contraindications: Initiate thrombolytic therapy in pulmonary embolism.

Low bleeding risk: systemic thrombolytic therapy
preferably tissue-type plasminogen activator (tPA), e.g., alteplase

High bleeding risk
patients with persistent hypotension
: catheter-directed thrombolytic therapy
( ultrasound-assisted direct infusion of thrombolytics into pulmonary artery via pulmonary arterial catheter)

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5) If thrombolytic therapy is ineffective or absolute contraindications are present: Consult interventional radiology and/or surgery for embolectomy

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6) Continuous telemetry and pulse oximetry

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7) ICU transfer

Question 21

how do you manage thrombolysis with patients receiving anticoagulation in massive PE

Answer 21

Discontinue anticoagulation prior to thrombolysis
Check aPTT 2 hours after completion of thrombolysis.
Resume anticoagulation when aPTT is < 2 times the upper normal limit.

Question 22

what is the contraindications for thrombolysis ?

Answer 22

absolute

Presence of structural intracranial disease
Prior intracranial hemorrhage
Ischemic stroke ≤ 3 months ago
Active bleeding
Recent spinal or brain surgery
Recent brain injury or head trauma with fracture

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relative

Systolic blood pressure > 180 mm Hg
Diastolic blood pressure > 110 mm Hg
Recent nonintracranial bleeding
Recent surgery
Recent invasive procedure
Ischemic stroke > 3 months ago
Current anticoagulation use

Question 23

what is complication of PE?

Answer 23

High risk of recurrence: Without anticoagulant treatment

Right ventricular failure and secondary pulmonary arterial hypertension

Sudden cardiac death due to pulseless electrical activity

Atelectasis (∼ 20% of cases)

Pleural effusion

Pulmonary infarction (∼ 10% of cases)

Question 24

dd of PE?

Answer 24

Postoperative atelectasis

Anxiety disorders