4.1 N Cvs Disorders Peripheral Vasculature (Dvt, Pe) Em Cam 257

Front 1

Regarding DVT, which is incorrect
1 a Wells score <2 excludes DVT
2 a D Dimer in combination with low pre-test probability excludes DVT
3 wells greater than or equal to 2 means DVT is likely and US should be performed
4 a negative ultrasound and likely DVT indicates repeat US testing at 5-7 days

Back 1

1 indicates low probability, perform ddimer

Front 2

What is the significance of positive d dimer? Negative?

Back 2

Positive is non specific, and does not rule in disease; may rise in infection, trauma, multiple other conditions

Negative is very helpful, high negative predictive value, can rule out disease. With low pretest probability effective excludes DVT

Front 3

Differential diagnoses for DVT

Back 3

Baker's cyst - rupture
Cellulitis
Arthritis
Cardiac failure/lower limb oedema
Post op oedema
Superficial thrombophlebitis
Venous insufficiency

Front 4

When is hospital based treatment indicated?
LMWH started and then warfarin, what is the target INR?
When should intravascular (catheter directed) thrombolysis be considered?
When should thrombectomy be considered?

Back 4

Swelling of whole limb, thrombus above groin, unstable patient
2-3
Extensive iliofemoral thrombus, esp if haemodynamic change suggestive multiple PE
Vital functions lower limb threatened, in order to reduce risk of post thrombotic syndrome

Front 5

How does the assessment of pregnant women differ?

Back 5

Not studied with regards to well's score/d-dimer. In general lower threshold for US is appropriate

Front 6

How is the below knee DVT treated differently - what are the options?

Back 6

Anticoagulate as per normal
Serial ultrasound to ensure not extending above knee
Venography in equivocal cases

Front 7

What to do if DVT produce recurrent emboli or there are contraindications for anti coagulation?

Back 7

Refer for IVC filter

Front 8

PE - diagnostic and treatment strategies rely on risk stratification to avoid excessive investigation, unnecessary therapy, and guide management. Decision to treat is based on reaching a diagnostic threshold where PE morbidity/mortality outweighs risk of anti coagulation. What is the percentage chance of PE at which this threshold is met?

Back 8

70-80%. Note that this % is higher if pt have high bleeding risk (frequent falls), lower if high risk from PE (pre existing lung/right heart disease).

Front 9

Regarding massive PE what is the initial Ix?
Unstable/shocked pt - treatment of choice?

Back 9

TTE or TOE
Thrombolysis, or thrombectomy

Front 10

What is the relevance of syncope with respiratory sx or signs in PE?

Back 10

Implies severe PE. Note these features may be transient

Front 11

What are the markers of right heart strain in PE? elevated JVP, loud S2, pulmonary systolic murmur

Back 11

elevated JVP, loud S2, pulmonary systolic murmur

Front 12

The role of screening tests in PE (ABG, ECG, CXR) is largely to exclude other causes. Some features suggestive of PE may be found however.

What might be seen on CXR, ECG?

Back 12

CXR - normal with hypoxia suggests PE. Hamptom's hump, pulmonary oligaemia or cut-off, enlarged descending or plump pulmonary artery

ECG - tachycardia, RBBB, RAD, TWI esp v1-3), S1q3t3
More feature of right ventricular strain, more suggestive of major PE and poorer outcome

Front 13

Regarding DDIMER in suspected PE, which is incorrect
1 high sensitivity tests may be used in low to intermediate risk populations eg <30% to rule out (rapid latex tests)
2 low sensitivity tests e.g. Simplired, most latex agglutination tests are only safe in low risk <10% chance patients to rule out
3 patients with prolonged symptoms are more likely to have false positive tests and should be excluded from this test
4 if unlikely to have neg d dimer e.g active ca, late pregnancy, shock, don't use test

Back 13

3 INCORRECT - more likely to have false NEGATIVE,and so ddimer shouldn't be performed. Prolonged sx =>1/52

Front 14

PIOPED study assessed value of VQ scan in PE investigation. True/false
1 it showed >50% of scans were non diagnostic and required additional testing
2 interobserver variability was low in the intermediate and low probability groups in scan reporting
3 a normal scan (which excludes PE) only occurred in 14% of study subjects
4 high probability scans were associated with an 85% chance of PE, and occurred in 30% of the study population
5 a patient with a dichotomous pretest risk (clinical probability) and VQ result e.g. Low risk, high prob on test, or high risk, low probability on test, need further definitive investigation
6 patients with intermediate clinical risk and intermediate result probability should be treated
7 low/intermediate combinations of clinical risk/VQ scan results may have serial or single ultrasounds as a subsequent investigation

Back 14

1 true
2 FALSE - as high as 70%
3 true - however this rate is probably higher in ED population and if patients with abnormal CXR are excluded
4 false - only 13% had high probability scans. Note that this meant that 15% of this group would have been unnecessarily anti coagulated
5 true
6 false - need further workup
7 true
Essentially the test's ability to offer definitive diagnoses was very limited.

Front 15

Regarding CTPA which is CORRECT
1 sensitivity for subsegmental emboli is high
2 in patients with low clinical risk a CT scan should be followed by DVT
3 CTPA sensitivity for PE approaches 100%
4 VQ scanning and us may be preferable in young female patients including pregnant women

Back 15

1 low
2 CT sufficient
3 90-100%, in high risk patients without alternative diagnoses not sufficient to exclude, may need to follow with LL US (this is as per Cameron p235 - I'm not sure if as relevant with newer scanners)
4 correct - depending on local equipment and protocols

Front 16

What is the role of Echocardiogram in PE?

Back 16

Dx of suspected massive PE with haemodynamic instability

Can exclude other causes hypotension/raised venous pressure e.g. Right vent infarct, valvular failure, tamponade

Can be performed in resus room

Identifies right heart strain in stable patients, important for prognosis (5-15% mortality in this group)

Insensitive for peripheral emboli

Front 17

Determinants of prognosis in PE

Back 17

Haemodynamic or respiratory failure
Right ventricular overload/strain
Severe VQ mismatch
Severe comorbidities

Front 18

Therapeutic clexane dose ?
Who goes to HDU?
What is the volume limit of IVF in haemodynamic instability and why?

Back 18

1mg/kg bd or 1.5 daily, reduce if poor renal function; if obese max dose 100mg
HDU for unstable, and stable but with right ventricular strain or major PE
1L given in 250-500ml aliquots, as right ventricle is overloaded and failing

Front 19

Thrombolysis
1 what is the benefit shown in massive PE
2 when is it indicated?

Who gets thrombectomy?

Back 19

1 decreased pulmonary artery pressures, improved right vent function, mortality benefit
2 haemodynamic instability eg massive PE

Haemodynamic instability or persistent hypoxia and contraindicated thrombolysis