Pulmonary embolism

Question 1

Hx: patient presents with SOB, pleuritic chest pain on inspiration, new cough and haemoptysis, low O2 sats?
+/- fever
+/- red swollen leg

Answer 1

PE

Question 2

if Hx is suggestive of PE, and on Ex:
• ↓ BP
• syncope
• ↑ HR
• RVF

Answer 2

high risk PE with haemodynamic instability; consider immediate primary reperfusion (thrombolysis)

Question 3

definitive diagnostic Ix for PE?

Answer 3

CTPA

Question 4

Virchow’s triad?

Answer 4

• venous stasis
• trauma
• hypercoagulability

Question 5

scoring system for VTE likelihood?

Answer 5

Wells score

Question 6

risk factors for PE?

Answer 6

mainly “DICE”:
• D - DVT or PE PMHx/FHx, or thrombophilia
• I - immobility (surgery last 2m, bed rest >5d, travel)
• C - cancer (prostrate, ovarian)
• E - eostrogen (pregn, COCP, HRT, BMI)

also:
• age
• recent # or trauma
• paralysis lower limbs
• smoking
• COPD, CHF, recent MI, sepsis, transfusion, nephrotic syndrome, polycythaemia, IBD
• CVC or varicose veins

Question 7

clotting abnormalities predisposing to VTE?

Answer 7

• factor v Leiden
• prothrombin mutation
• antithrombin, protein C or S def
• antiphospholipid Ab syndrome
\+/- secondary:
• nephrotic syndrome
• antiphospolipid
• Behcets
• CA
• DIC
• pregn
• polycythaemia

Question 8

Ex findings in PE?

Answer 8

• ↓ O2
• cyanosis
• ↑ JVP
• ↑ RR ↑ HR
• +/- pleural rub, effusion
• +/- fever
• gallop rhythm, right ventricular heave
• +/- cough, haemoptysis
• +/- shock Ex

Question 9

Ix PE?

Answer 9

BEDSIDE:
• Wells Score** (>4)
• ECG (sinus tachycardia +/- T inversion V1-3 due to RV strain)

BLOODS:
• if Wells -ve, D-dimer
• FBC, U+E, LFTs
• coag - PT and INR baseline
\+/- ABG (↓O2, ↓CO2, ↑pH)
\+/- unprovoked? thrombophilia screen
\+/- troponin (ΔΔ MI)

IMAGING:
\+/- CXR (often normal, occasional ↓vascular markings, small pleural effusion, wedge shaped infarct, atelectasis)(ΔΔ CAP, Ca)
\+/- US + doppler (DVT)
• ***CTPA (diagnostic)
• ECHO
\+/- V/Q scan

Question 10

ECG findings in PE?

Answer 10

• 50 percent have **sinus tachycardia
20-30 percent have:
• T wave inversion V1-3 (right ventricle strain)
• S1Q3T3 (prominent S in lead I, Q wave and inverted T in III)
• RBBB
• R axis deviation

Question 11

Tx PE?

Answer 11

haemodynamically unstable +/- hypoxaemia?
• ABCDE
• fluid rescusc

heamodynamically unstable?
• UF heparin
+ thrombolysis
+/- surgical embolectomy

stable?
• LMWH

stable but can’t anticoagulate?
• venous filter

ongoing?
• LMWH then to DOAC/warfarin
• TED stockings

Question 12

Tx PE?

conservative/med/surgical

Answer 12

conservative:
• TED stockings
• start 1 week after DVT
• continue for 2 years

medical:
ACUTE
• therapeutic LMWH/fondaparinux SC
• for 5 days/ until INR >2
• if haemodynamically unstable - SBP <90 (alteplase)

LONG-TERM
• overlap DOAC or warfarin with LMWH for 72 hours
• 3 months if provoked
• 6 months if unprovoked/active CA
• permanent if second VTE

surgical:
• embolectomy
• venous filter
+/- thrombectomy if ileofemoral DVT and low risk for surgery

Question 13

causes of PE:

Answer 13

• blood clot (immobility, surgery, active inflammation - IBD, pregnancy, COCP, HRT, thrombophilia, CA)
• fat
• fluid
• infective emboli

Question 14

when to consider a thromphilia screen in VTE?

Answer 14

• <40 years old
• recurrent VTE
• FHx VTE
• weird site like portal vein

Ix:
• blood smear
• fibrinogen level
• lupus Ab
• antithrombin III, protein C and protein S assays