Maryam AL-Qahtani presented on pulmonary embolism. The key investigations for a PE patient are a D-dimer test, CT pulmonary angiography, isotope lung scanning, and leg ultrasound. For treatment, anticoagulants like heparin, low molecular weight heparins (LMWH), and warfarin are given as prophylaxis or therapy. The types of heparin are unfractionated heparin and LMWH, which differs in molecular weight, activity against coagulation factors, side effects, and half-life. Physicians consider effectiveness, safety and cost when deciding which type of heparin to use.

1. Present by: Maryam AL-Qahtani
Week3

2. Introduction
Pulmonary embolism
Is when one or more pulmonary
arteries in lungs become blocked.
Caused by blood clots
that TRAVEL to the lungs from
the legs or rarely other parts of
the body (deep vein thrombosis).

3. Objectiv
eWsha:t are the specific investigation to be done for a PE
patient ?
What are the anticoagulation agent which can be given
in pulmonary embolism as a prophylactic or therapeutic ?
What are the different types of heparin ?

4. What are the
specific
investigation to be
done for a PE
patient ?

5. The choice and order of investigations will
depend on
The clinical likelihood of PE.
How ill the patient is (stable or unstable).
Availability of the test.

6. D-dimer test
Degradation product of cross-linked fibrin.
 Elevated in plasma in the presence of clot
because of the activation of coagulation and
fibrinolysis.
A sensitivity of >95% and effectively
excludes PE.
Qualitative d-dimer tests are less reliable, but
they have been used safely in the primary care
setting with the wells rule in excluding PE.

7. The specific investigation :
Computed tomographic pulmonary
angiography.
Isotope lung scanning (V/Q scan;Ventilation-perfusion
lung scintigraphy).
Leg ultrasound.

8. Computed tomographic pulmonary
angiography.

9. CTPA has become the method of choice for imaging the
pulmonary vasculature in patients with suspected PE
Why ?
Its wider availability
Ability to demonstrate alternative causes of symptoms.
Fast and generally well tolerated
Has superior sensitivity for the detection of small
subsegmental emboli (detects clots in smaller vessels.)

10. Isotope lung scanning (V/Q scan)

12. A ventilation/perfusion lung scan(a V/Q
to evaluate the circulation of air and blood within a
patient's lungs, in order to determine the
ventilation/perfusion ratio.
The ventilation part of the test looks at the ability of air to
reach all parts of the lungs-while
the perfusion part evaluates how well blood circulates
within the lungs.
lung scan)

13. VQ or CTPA?
Both accurate
CTPA :widespread availability
VQ scanning: may not be available outside working hours.
Radiation dose of VQ is significantly less than CTPA, which makes VQ
preferable for young women.
There is a higher risk of contrast-induced nephropathy with intravenous
contrast for CTPA in patients with moderate-to-severe renal impairment and
VQ is preferable in these patients.

14. Leg ultrasound

15. Why ?
High sensitivity for detection of proximal deep vein thrombosis
(DVT), which is the source of PE in 90% of patients.
 A positive lower limb us is present in 30–50% of patients with
PE.
Useful where tests using ionising radiation are less desirable,
for example in pregnancy.

16. What are the anticoagulation agent
which can be given in pulmonary
embolism as a prophylactic or
therapeutic ?

17. Anticoagulation
Anticoagulants work by increasing the
time it takes a blood clot to form. They
also prevent a clot from getting bigger.
Immediate therapeutic anticoagulation
should be initiated for patients in whom
DVT or pulmonary embolism (PE)
Anticoagulation therapy reduces
mortality rates from 30% to less than
10%

18. Prophylactic anticoagulation agents:
• Most hospitalized patients developed VTE.
• The estimated risk factor is high as 50% when
thromboporphylaxis is not used.
Prophylaxis measurements
• Early mobilization.
• Elevation of the legs.
• Compression stocking.
• Intermittent compression device.
• Use of drug such as : LMWH , and Anti-thrombin.

19. Therapeutics anticoagulation agents:
Aim of Treatment:
prevent further thrombosis and PE while resolution of venous
thrombi occur by natural fibrinolytic activity.
1. Start w. : Heparin as its produced direct effect, For 5 Days
2. LMWH e.g. (Tinzaparine 175 U/kg daily, Delteparin 200 U/kg daily,
Enoxaprain 1.5 mg/kg daily) is effective and safe for immediate treatment as
unfractionated heparin.
3. At the follow up : For Long –term medication will use warfarin to maintain a
target INR of 2.0-3.0

20. Length of Anti-Coagulation
• 6 weeks for isolated calf vein thrombosis.
• 3 months after participated proximal DVT or PE in
patient with temporary risk factors.
• 3 to 6 months in idiopathic VTE or permanent risk
factors.

21. Outpatient
• Best to be supervised in anticoagulant clinics.
• IVC filters are an important tool to prevent PE in patients that
have a contraindication to anticoagulation.

22. Summary :
• Start the therapy by Heparin or low molecular
weight heparin (LMWH) followed by …
• 6 months Warfarin with an international normal
ratio of 2 to 3.

23. What are the
different types
of heparin ?

24. Heparin
An anticoagulant or a medication that prevents clots from forming
Attaches to antithrombin III
Antithrombin III is a protein that breaks up substances that will
form a clot.
With heparin attached to it, antithrombin III is 1,000 times more
effective

25. Types of heparin
Heparin (standard
Unfractionated)
Low-Molecular-
Weight Heparins

26. Heparin (standard Unfractionated)
• Mixture of polysaccharides.
• Consist of components with molecular weight varying from
5000-35000.
• Inactivates several coagulation enzymes, including Factors IIa
(thrombin), Xa, IXa, XIa, and XIIa.
Low-Molecular-Weight Heparins
• Producing fractions with molecular weight in the range of
2000-8000.
• It has greater activity against factor Xa than against factor IIa.

27. Mechanism

28. Differenc
Bioavailability: es
LMWH is better than that of unfractionated heparin.
Activity against factor:
Inactivates several coagulation enzymes while LMWH greater
activity against factor Xa than against factor IIa, suggesting that
they may produce an equivalent anticoagulant effect to standard
heparin.
Side effect:
LMWH have a lower risk of bleeding and less inhibition of platelet
function.
half-life:
LMWH have a longer half-life than standard heparin and
so can be given as a once-daily subcutaneous injection
instead of every 8–12 h.

29. Fondaparinux
• Inhibits activate factor X, similar to the LMW heparins.
• Binds to AT with a higher affinity
• Cannot bind to and inactivate thrombin (factor IIa)
• Not expected to induce thrombocytopenia
• 100 percent bioavailable after subcutaneous injection
• The half-life of this agent is much longer (15 to 17 hours)

30. Side effect
• >10%
Heparin-induced thrombocytopenia, possibly delayed (10-30% )
Frequency Not Defined
• Mild pain
• Hematoma
• Hemorrhage
• Local irritation
• Erythema
• Injection site ulcer (after deep SC injection)
• Increased liver aminotransferase
• Anaphylaxis
• Immune hypersensitivity reaction
• Osteoporosis (long-term, high-dose use)

31. Physicians decide which type of
heparin to use based upon:
 Effectiveness
 Safety
Cost.

33. References
 Merck Manual.
 .Up to data.website
 Kumar and Clark book
 http://atvb.ahajournals.org/content/21/7/1094.long
 http://www.livestrong.com/article/252722-types-of-heparin/
 http://www.thrombosisadviser.com/en/vte-prevention/
heparins/
 http://emedicine.medscape.com/article/300901-treatment
 http://reference.medscape.com/drug/calciparine-monoparin-
heparin-342169#4