Pulmonary embolism Flashcards
Discuss clinical features of a DVT
Initial symptoms are subtle and nonspecific such as cramping and sensation of fullness in the calf – many patients use the term charley horse to describe the sensation of an early DVT
As the left iliac vein is vulnerable to compression by the left iliac artery leg DVT occurs with a slightly higher frequency inthe left leg
Bilateral is uncommon seen in only 10% of patietns
Signs vary and may include oedema, erythema, wartmth tenderness to palpation and a palapble venous cord.
Discuss the LEFt score for pre-test probability in pregnant patients
1 point if case of left leg suspicion
1 point if oedema
1 point if suspscion in the first trimester
Score of 0 or 1 is low pretest probability
Discuss Wells Criteria for deep vein thrombosis
Score of 0 is low pretest -5%
1-2 moderate pretest 17%
3 or more high pretest 17-53%
- Active cancer
- Paralysis paresis or recent plaster immbolisation of the lower limb
- Recently bedridden for>3 days or major surgery within 12 weeks requiring general or regional anesthesia
- localized tendernes along the distribution of the deep venous system
- entire leg oedema
- calf swelling at least 3cm larger than on the asymptomatic side (measured 10cm below the tib tuberosity)
- Pitting oedema confined to the symptomatic leg
- Collateral superifical veins
- previously documented DVT
- Alternaitve diagnosis at least as likley as DVT
List differential of DVT
Chronic venous insufficiency cellulitis muscle strain or tear baker's cyst haematoma claudication/ishcemia intra-abdominal compression unrecognized trauma
List differential of DVTp
for those with a high PTP after hours and with a positive ultrasound anticogaulation should be initiaed emergently unless contraindicated
Enoxaparin therapeutic
Rivaroxaban
Based on a recent large RCT patient with clots in the greater saphenous that extends above the knee are at risk of DVT via the saphenofemoral juntction- depnding on proximity to the SFJ may require short course of anticoagulation and repeat ultrasound
Discuss phlegmasia cerulea dolens and its management
Massive illiofemoral vein occlusions results in swelling of the entire leg with extensive vascular congestion and associated venous ischaemia – producing a painful cyanotic extremity
Requries urgent vascular review may require thrombectomy - if not available need to consider thrombolysis
Discuss treatment of upper limb DVT
-becoming more common due to increase use of indwelling catheters
Requires treatment – removal of line and anticoagulation as for lower limb DVT for 3 months
Can cause PE but tend to be less sever than lower limb DVT
Discuss HESTIA criteria
Set of criteria to select patient with DVT or PE who can be treated in an OPD setting
Criteria include
1) systolic blood pressure >100mmhg
2) no thrombolysis needed
3) No active bleeding
3) no o2 required to mainatin saturation >94%
4) not already anticoagulated
5) absence of severe pain requiring two doses of intravenous narcotics
6) other medical or social reaons to admit
7) creat clearnace >30ml/min
8) non pregnant, sever liver disease or HITS
Discuss Wells criteria for PE
- Clinical signs and symptoms of DVT +3
- PE is #1 diagnosis or equally likley +3
- HR >100 +1.5
- Immobilisation at last 3 days or surgery in the previous 4 weeks +1.5
- Previous DVT or PE + 1.5
- Haemoptysis +1
- Malignancy w/ treatment within 6 months or palliative +1
0-1 low risk
2-6 moderate risk
>6 high risk
Discuss PERC criteria
If low pretest probability can be used to exclude embolism
- age >50
-HR <100
O2 >94%
-no haemoptysis
-no unilateral leg swelling
-no recent major surgery or trauma
-no prior PE
-nil hormone use
Discuss CXR in PE
Seldom provides specific information but is useful to suggest alternaitve diagnosis - pneumonia, CCF or pneumothorax.
If symptoms have been present for 3 days or more a pulmonary infarct may be visibile on CXR as an apex central, pleural based wedge shaped area of infiltrate (hamptoms hump)
Discuss the ECG in PE
Good for exclusion of other ddx
When PE causes ECG changes it is usually a result of acute of subactue pulmonary HTN
Most common signs of pulonary HTN are , tachycardia, symmetrical t-wave inversion in the anterior leads and the mcQinnwhite S1Q3S3 and incomplete or complete RBBB
Discuss investigation of PE in pregnancy
The algorithm begins with bilateral lower limb DVT scans – if positive treatment can be started
Next step is to find the PTP – over half of all VTE cases diagnosed in pregnancy occur in the third trimester
Approach of combined -ve lower limb DVT with combined -ve PERC and threshold adjusted d-dimer assay. D-dime can be adjusted as follow 750 for 1st trimester, 1000 2nd and 1250 for 3rd.
If patient has a low PTP, -ve lower limb ultrasound, -ve perc and -ve adjusted dimer PE can be excluded.
If fail any of the above need definitive management discuss with radiology
Define Massive and submassive and non massivePE and give mortality rates
Massive - HD unstable sustained hypotension (systolic blood pressure <90 mmHg for at least 15 minutes or requiring inotropic support, not due to a cause other than PE) –>15% mortality –> thrombolyse/embolectomy
Submassive - HD stable with evidence of RV dysfunction - TNI leak
Non massive haemodynamically stable with normal RV function -> anticoagulation
Discuss fibrinolytic therapy in PE
All patient with persistent hypotension should recieve full dose fibrinolysis (100mg alteplase or tier dosed tenectaplse)
Contronversy has been made more complex by a recent study suggesting a possible lower risk of signifianct haemorrhage associated with the lower half dose alteplase administered by peripheral vein
Moreover many large treatment centres have adopted the use of catheter directed thrombolysis which administers the firinolytic directly into the thrombos - the potentional advantage of this is lower risk of haemorrhage secondary to lower dose agent
