Pulmonary Embolism Flashcards
What are the symptoms of PE?
Pleuritic chest pain
Haemoptysis
Dyspnoea, tachycardia >100bpm, tachypnoea >20/min
Pulmonary embolism can be difficult to diagnose as it can present with virtually any cardiorespiratory symptom/sign depending on it’s location and size.
true
Classically patients present with a clear chest but in real life you may have what on respiratory examination?
crackles
What are the common clinical signs of PE?
Tachypnea (respiratory rate >20/min) - 96%
Crackles - 58%
Tachycardia (heart rate >100/min) - 44%
Fever (temperature >37.8°C) - 43%
What is PERC criteria?
Criteria for excluding PE in low-risk patients
How do you get a negative PERC result?
all the criteria must be absent to have negative PERC result
a negative PERC reduces the probability of PE to < 2%
What are the criteria of PERC?
Age >/50
HR >/100
Previous DVT or PE
Oestrogen use
Oxygen saturations 94%
Recent surgeyr or trauma past 4 weeks
Haemoptysis
Unilateral leg swelling
What is defined as low-probability of having a PE?
< 15%
If a PE is suspected what score should be performed?
Wells Score
Which components of the wells score are worth 3 points?
Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins)
An alternative diagnosis is less likely than PE
Which components of the wells score are worth 1.5 points?
Heart rate > 100 beats per minute
Immobilisation for more than 3 days or surgery in the previous 4 weeks
Previous DVT/PE
Which components of the wells score are worth 1 point?
Haemoptysis
Malignancy (on treatment, treated in the last 6 months, or palliative)
Describe wells scoring
Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins) 3
An alternative diagnosis is less likely than PE 3
Heart rate > 100 beats per minute 1.5
Immobilisation for more than 3 days or surgery in the previous 4 weeks 1.5
Previous DVT/PE 1.5
Haemoptysis 1
Malignancy (on treatment, treated in the last 6 months, or palliative) 1
Describe the clinical probability of a PE according to Well’s score
PE likely - more than 4 points
PE unlikely - 4 points or less
What should you do if PE is likely according to Well’s score?
arrange an immediate computed tomography pulmonary angiogram (CTPA)
If there is a delay in getting the CTPA then interim therapeutic anticoagulation should be given until the scan is performed.
What does interim therapeutic anticoagulation refer to?
Giving a direct oral anticoagulant (DOAC)
I.e. apixaban or rivaroxaban
What would you consider if CTPA is negative for PE?
consider a proximal leg vein ultrasound scan if DVT is suspected
What would you do if a PE is ‘unlikely’ according to Well’s Score?
arrange a D-dimer test (within 4 hours)
IF D DIMER POSITIVE:
Follow up with CTPA
If there is a delay in getting the CTPA then give interim therapeutic anticoagulation until the scan is performed
IF D DIMER NEGATIVE
if negative then PE is unlikely - stop anticoagulation and consider an alternative diagnosis
D dimers should be performed within what time frame?
4 hours
If can’t get results within 4 hours give interim therapeutic anticoagulation
What are the advantages of CTPA over V/Q scans?
speed, easier to perform out-of-hours
a reduced need for further imaging and the possibility of providing an alternative diagnosis if PE is excluded
What is the investigation of choice if there is renal impairment?
V/Q scanning
doesn’t require the use of contrast unlike CTPA
What is the sensitivity and specificty of D Dimers?
sensitivity = 95-98%, but poor specificity
When should age adjusted d-dimers levels be considered?
> 50 years
What are the classic ECG changes in PE?
‘S1Q3T3’
large S wave in lead I
large Q wave in lead III
an inverted T wave in lead III
However, this change is seen in no more than 20% of patients
Which bundle branch block is associated with PE?
right bundle branch block
Which axis deviation is associated with PE?
right axis deviation
Why is CXR reccomended in all suspect PE patients? What would you find?
to exclude other pathology
typically normal in PE
possible findings include a wedge-shaped opacification
What is the sensitivity & specifity of V/Q?
What else can cause a V/Q mismatch?
sensitivity of around 75% and specificity of 97%
other causes of mismatch in V/Q include old pulmonary embolisms, AV malformations, vasculitis, previous radiotherapy
What is a shortcoming of CTPA?
peripheral emboli affecting subsegmental arteries may be missed
In recent years, more and more ‘low risk’ patients are treated as outpatients. Key requirements to being low risk include what?
haemodynamic stability, lack of comorbidities and support at home
What is the cornerstone of VTE management?
anticoagulant therapy
What is the first line treatment for PE with haemodynamic instability?
Thrombolysis
other invasive approaches should be considered where appropriate facilities exist
Patients who have repeat pulmonary embolisms, despite adequate anticoagulation, may be considered for?
inferior vena cava (IVC) filters
stopping clots formed in the deep veins of the leg from moving to the pulmonary arteries
What should be offered first-line following the diagnosis of a PE?
Direct oral anticoagulants (DOACS)
i.e. apixaban or rivaroxaban
What is second line following diagnosis of a PE?
if neither apixaban or rivaroxaban are suitable then either:
LMWH followed by dabigatran (DOAC) or edoxaban OR
LMWH followed by a vitamin K antagonist (VKA, i.e. warfarin)
What should be offered first-line following the diagnosis of a PE in active cancer?
DOAC apixaban or rivaroxaban, unless this is contraindicated
What should be offered first-line following the diagnosis of a PE in severe renal impairment?
LMWH, unfractionated heparin or
LMWH followed by a VKA
What should be offered first-line following the diagnosis of a PE in antiphospholipid syndrome?
LMWH followed by a VKA should be used
All patients should be on anticoagulation how long after PE?
at least 3 months
After 3 months of anticoagulation post PE, what deterines if this is continued further?
if VTE was provoked (The implication is that this event was transient and the patient is no longer at increased risk) or unprovoked
After 3 months of anticoagulation post PE, and the VTE was provoked, what is the implication?
The implication is that this event was transient and the patient is no longer at increased risk
After 3 months of anticoagulation post PE, and the VTE was UNPROVOKED, what is the implication?
there is a possibility that there are unknown factors (e.g. mild thrombophilia) making the patient more at risk from further clots
After 3 months of anticoagulation post PE when is treatment STOPPED?
if the VTE was provoked the treatment is typically stopped after the initial 3 months
After 3 months of anticoagulation post PE when is treatment CONTINUED?
if the VTE was unprovoked then treatment is typically continued for up to 3 further months (i.e. 6 months in total)
If PE was provoked and the patient has active cancer, how long should anticoagulation be?
if the VTE was provoked the treatment is typically stopped after the initial 3 months
BUT it can be 3 to 6 months for people with active cancer
What score can help assess someones risk of bleeding?
HAS-BLED score
A 64-year-old woman presents to the emergency department with sudden onset shortness of breath, pleuritic chest pain, and fatigue. Her heart rate is 136/min, respiratory rate is 32/min, blood pressure is 85/50mmHg, with a temperature of 37.4ºC. Computed tomography pulmonary angiography confirms a saddle-shaped pulmonary embolus (PE).
What initial medical management would be advised at this point?
Alteplase
Massive PE + hypotension - thrombolyse
in cases of severe PE or when bridging from oral anticoagulation if patients require surgery and need better control in the meantime what drug is appropriate?
Unfractionated heparin
pulmonary embolism rx & air travel
- 01 cases per million for travel under 5,000 km
- 5 cases per million for travel between 5,000 - 10,000 km
- 8 cases per million for travel over 10,000 km
pulmonary embolism rx & air travel here is no universal agreement on what to advise patients.
true
pulmonary embolism rx & air travel a patient with no major risk factors for VTE (i.e. the average person) then no special measures are needed.
true
pulmonary embolism rx & air travel Patients with major risk factors should be given aspirin
false
All guidelines agree there is no role for aspirin in low, medium or high risk patients.
pulmonary embolism rx & air travel Patients with major risk factors should consider wearing anti-embolism stockings.
true
pulmonary embolism rx & air travel when should special consideration be given
if the risk is very high (e.g. a long-haul flight following recent major surgery) then consideration should be given to delaying the flight or specialist advice sought regarding the use of low-molecular weight heparin.
If a patient is suspected of having a DVT which score should be performed
a two-level DVT Wells
What is the difference between Well’s score for DVT & PE?
Clinical probability scoring different. DVT >/2 points likely, PE >/4 points likely
Points for risk factors:
PE 3, 1.5 or 1 per risk factor
DVT mostly 1 point per risk factor or -2
Immobilisation in PE is surgery within 4 weeks whereas DVT major surgery within past 12 weeks
In what way is DVT & PE mx the same?
If DVT/PE unlikely d dimer performed
DOAC such as apixaban or rivaroxiban is used if first line ix +ve
Two-level DVT Wells score is used for
DVT
Describe Wells score rx factors for DVT in terms of SYMPTOMS
Pitting oedema confined to the symptomatic leg
Collateral superficial veins (non-varicose)
Localised tenderness along the distribution of the deep venous system
Calf swelling at least 3 cm larger than asymptomatic side
Entire leg swollen
Each sx worth 1 point
Describe Wells score rx factors for DVT in terms of PMH
Previously documented DVT
Active cancer (treatment ongoing, within 6 months, or palliative)
Paralysis, paresis or recent plaster immobilisation of the lower extremities
Recently bedridden for 3 days or more or major surgery within 12 weeks requiring general or regional anaesthesia
Which Wells score rx factor in DVT is worth -2 points?
An alternative diagnosis is at least as likely as DVT
If a DVT is ‘likely’ (2 points or more) what ix should be performed
a proximal leg vein ultrasound scan should be carried out within 4 hours
IF RESULT POSITIVE
diagnosis of DVT is made and anticoagulant treatment should start
IF RESULT NEGATIVE
D-dimer test should be arranged. A negative scan and negative D-dimer makes the diagnosis unlikely and alternative diagnoses should be considered
If a DVT is ‘likely’ (2 points or more) & if a proximal leg vein ultrasound scan cannot be carried out within 4 hours what ix
D-dimer test should be performed and interim therapeutic anticoagulation administered whilst waiting for the proximal leg vein ultrasound scan (which should be performed within 24 hours)
in DVT what does interim anti coagulation refer to?
this means normally a direct oral anticoagulant (DOAC) such as apixaban or rivaroxaban
anticoagulant that can be continued if the result is positive.
In DVT mx if scan is negative but the D-dimer is positive:
stop interim therapeutic anticoagulation
offer a repeat proximal leg vein ultrasound scan 6 to 8 days later
If a DVT is ‘unlikely’ (1 point or less) what ix
perform a D-dimer test
this should be done within 4 hours. If not, interim therapeutic anticoagulation should be given until the result is available
IF RESULT NEGATIVE
DVT is unlikely and alternative diagnoses should be considered
IF RESULT POSITIVE
if the result is positive then a proximal leg vein ultrasound scan should be carried out within 4 hours
if a proximal leg vein ultrasound scan cannot be carried out within 4 hours interim therapeutic anticoagulation should be administered whilst waiting for the proximal leg vein ultrasound scan (which should be performed within 24 hours)
apixaban or rivaroxaban (both DOACs) should be offered when in DVT
first-line following the diagnosis of a DVT
as interim - DOAC once a diagnosis is suspected, with this continued if the diagnosis is confirmed
DVT if neither apixaban or rivaroxaban are suitable then
same as PE
LMWH followed by dabigatran or edoxaban OR LMWH followed by a vitamin K antagonist (VKA, i.e. warfarin)
DVT if the patient has active cancer
using a DOAC, unless this is contraindicated
DVT if renal impairment is severe (e.g. < 15/min)
same as PE
then LMWH, unfractionated heparin or LMWH followed by a VKA
DVT if if the patient has antiphospholipid syndrome
same as PE
then LMWH followed by a VKA should be used
DVT all patients should have all patients should have anticoagulation for at least 6 months
false
same as PE - 3 months
Describe length of anticoagulation rules in DVT
same as PE
continuing anticoagulation after this period is partly determined by whether the VTE was provoked or unprovoked
a provoked VTE is due to an obvious precipitating event e.g. immobilisation following major surgery. The implication is that this event was transient and the patient is no longer at increased risk
an unprovoked VTE occurs in the absence of an obvious precipitating event, i.e. there is a possibility that there are unknown factors (e.g. mild thrombophilia) making the patient more at risk from further clots
if the VTE was provoked the treatment is typically stopped after the initial 3 months (3 to 6 months for people with active cancer)
if the VTE was unprovoked then treatment is typically continued for up to 3 further months (i.e. 6 months in total)
NICE recommend that whether a patient has a total of 3-6 months anticoagulant is based upon balancing a person’s risk of VTE recurrence and their risk of bleeding
true
Unprovoked VTE in the absence of a bleeding risk factors, patients are generally better off continuing anticoagulation for a total of 6 months
true
Explain to people with unprovoked DVT or PE and a low bleeding risk that the benefits of continuing anticoagulation treatment are likely to outweigh the risks
