Pulmonary Embolism Flashcards
List miscellaneous risk factors for PE.
COPD, neurological disability, occult malignancy, thrombotic disorder, long distance travel, obesity, other (IBD, nephrotic syndrome, dialysis, myeloproliferative disorders, paroxysmal nocturnal haemoglobinuria, Bechet’s disease)
List 6 major risk factors for PE
Surgery – major abdominal/pelvic, hip/knee replacements, post ICU
Lower limb problems – #, varicose veins
Obstetrics – late pregnancy, C/S, puerperium
Malignancy – abdominal/pelvic, advanced/metastatic
Mobility – hospitalization, institutional care
Previous VTE
List 7 thrombophilias associated with PE and DVT formation.
Factor V Leiden mutation
Prothrombin gene mutation
Hyperhomocysteinaemia
Antiphospholipid antibody syndrome
Deficiency of antithrombin III, protein C or protein S
High concentrations of factor VIII or XI
Increased lipoprotein (a)
What are the markers of RV dysfunction.
RV dilatation, hypokinesis or pressure load on echocardiography
RV dilation on spiral CT
BNP or NT-proBNP elevation
Name three markers useful for risk stratification in acute PE.
Clinical markers including shock and hypotension
RV dysfunction markers
Markers of myocardial injury: Troponin T/I
Which joint replacement has the highest risk of developing DVT?
Anke replacement more than hip and knee replacement
Why: Longer duration of immobility
What is the best diagnostic test for PE?
CT angiography
Alternative is V/Q scan
What is the initial test done for PE?
CXR which is usually normal and ABG then EKG
List 5 common risk factors for DVT in order.
Immobility
Malignancy
Trauma
Surgery especially joint replacement
Thrombophilias such as factor V mutation, antiphospholipid syndrome and protein c/S deficiency
Which thrombophilia has the greatest risk of DVT?
Antiphospholipid syndrome (lupus anticoagulant)
Most likely to recur and need life long therapy
What is the most common finding on CXR of PE if it is abnormal? Also name other findings.
Atelectasis
Others: Wedge shaped infarction and pleural based hump(Hampton hump)
What is the most common EKG finding in PE?
Sinus Tachycardia
What is the most common EKG finding of PE when the EKG is ABNORMAL?
Non specific ST-T wave changes (reported in 50% of patients with PE)
Followed by Right axis deviation(16% of PE) and less likely extreme Right axis deviation, Right bundle branch block (18% of patients) and P pulmonale(9% of patients)
NOTE: S1Q3T3 IS A LATE FINDING AND RARE
What is the ABG finding of pulmonary embolism?
Mild respiratory alkalosis with hypoxia and increased A-a gradient
Metabolic acidosis with circulatory collapse can be seen
What ABG finding excludes the presence of PE?
Respiratory acidosis
What are the findings of PE that are indications for thrombolytics?
RV heart strain and hypotension(hemodynamic instability)
What is the initial treatment of PE?
Low molecular weight heparin or Unfractionated Heparin
Which test rules out PE?
Negative D dimer
Usually done when you are uncertain if a person has PE or not especially when it is unlikely while there are other options available to choose from
What is the treatment of choice if the person has bleeding and a diagnosed PE?
Inferior vena cava filter
You can’t use anticoagulant
Even when you have Pulmonary hypertension Inferior vena cava filter is the correct thing.
What is a classic finding of pulmonary embolus on EKG?
Deep S wave in lead 1; Q wave and inverted T wave in lead 3
Which EKG finding in PE is associated with high pulmonary arterial pressure and is seen in34% of patients with PE?
Right ventricular strain characterized by TWI (T wave inversions) in the right precordial leads (V1-4) ± the inferior leads (II, III, aVF)
What is the commonest arrhythmia seen in PE?
Atrial fibrillation
List ECHO findings that makes PE likely.
Right ventricular dilatation
Right ventricular size does not change from diastole to systole
D shaped left ventricle
Acute tricuspid regurgitation
Inferior vena cava >2.5cm and < 50% collapse
40% of patients with a PE will have right ventricular abnormalities on echo
Paradoxical septal motion towards the LV
Name two conditions that makes it difficult to interpret the VQ scan.
COPD AND ASTHMA
Only perform in those with normal appearance
What should be the initial test for pregnant women suspected of having a PE?
Shielded CXR and lower limb Doppler ultrasound
If the patient has a DVT and clinical signs that suggest PE then treatment should be commenced and no further imaging is required
PERC (pulmonary embolism rule out criteria)
Low risk of PE (decided either through clinical evaluation or low risk Wells)
Is the patient older than 49 years of age?
Is the pulse rate above 99 beats min?
Is the pulse oximetry reading <95% while the patient breathes room air?
Is there a present history of hemoptysis?
Is the patient taking exogenous estrogen?
Does the patient have a prior diagnosis of venous thromboembolism (VTE)?
Has the patient had recent surgery or trauma? (Requiring endotracheal intubation or hospitalisation in the previous 4 weeks.).
Does the patient have unilateral leg swelling?
What is the initial treatment of massive PE?
Thrombolytics if ineffective embolectomy
Ionotropic support may be required
What is the initial treatment of submassive PE that is hemodynamically stable with evidence of RV dysfunction?
Thrombolytics followed by embolectomy if ineffective
What is the initial treatment for mild PE?
LMWH or enoxaparin
What are the management goals of PE?
(1) prevent further embolism
(2) removal of emboli (massive or sub-massive)
(3) haemodynamic support (massive)
What are the discharge criteria for PE?
Patient needs to be haemodynamically stable
Any concomitant conditions under control
INR must be therapeutic
Social situation adequate
What preventative measures are implemented in the hospital to reduce prevalence of PE?
Identify patients at risk
Mechanical – Compression stockings or pneumatic compression devices
Chemical – Enoxaparin 40mg SC once daily or heparin 5000 IU SC 8 hourly.
