Difference between revisions of "Pulmonary embolism"

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*Pulmonary foreign body embolism.
*Pulmonary foreign body embolism.
*Pulmonary septic embolism.
*Pulmonary septic embolism.
*Pulmonary bone marrow embolism.
*Pulmonary tumour embolism.
*Pulmonary amniotic fluid embolism.


PE usually refers to '''pulmonary venous thromboembolism''', abbreviated '''VTE''', if not otherwise specified.
PE usually refers to '''pulmonary venous thromboembolism''', abbreviated '''VTE''', if not otherwise specified.


==Clinical==
==General==
*Shortness of breath (dyspnea) - classic symptom.
*Relatively uncommon ~ 1 in 1000 adults per year.<ref name=pmid20852464>{{Cite journal  | last1 = Meetoo | first1 = D. | title = In too deep: understanding, detecting and managing DVT. | journal = Br J Nurs | volume = 19 | issue = 16 | pages = 1021-7 | month =  | year =  | doi =  | PMID = 20852464 }}</ref>
*Diagnosis in life dependent on strong clinical suspicion and radiology.
 
===Clinical===
*Shortness of breath ([[dyspnea]]) - classic symptom.
*Tachycardia.
*Tachycardia.
*Chest pain.
*Chest pain.
*Findings associated with deep vein thrombosis
*Findings associated with deep vein [[thrombosis]].
**Leg pain.
**Leg pain.
**Leg swelling.
**Leg swelling.
Line 18: Line 25:
*Venous thrombosis OR~=12 for PE.<ref name=pmid20648405>{{cite journal |author=Reissig A, Haase U, Schulze E, Lehmann T, Kroegel C |title=[Diagnosis and therapy of pulmonary embolism prior to death] |language=German |journal=Dtsch. Med. Wochenschr. |volume=135 |issue=30 |pages=1477–83 |year=2010 |month=July |pmid=20648405 |doi=10.1055/s-0030-1262435 |url=}}</ref>
*Venous thrombosis OR~=12 for PE.<ref name=pmid20648405>{{cite journal |author=Reissig A, Haase U, Schulze E, Lehmann T, Kroegel C |title=[Diagnosis and therapy of pulmonary embolism prior to death] |language=German |journal=Dtsch. Med. Wochenschr. |volume=135 |issue=30 |pages=1477–83 |year=2010 |month=July |pmid=20648405 |doi=10.1055/s-0030-1262435 |url=}}</ref>


==Risks factors (VTE)==
===Mechanism===
*Trauma.
The classic factors are given by ''Virchow's triad'':<ref name=pmid22345594>{{Cite journal  | last1 = Reitsma | first1 = PH. | last2 = Versteeg | first2 = HH. | last3 = Middeldorp | first3 = S. | title = Mechanistic view of risk factors for venous thromboembolism. | journal = Arterioscler Thromb Vasc Biol | volume = 32 | issue = 3 | pages = 563-8 | month = Mar | year = 2012 | doi = 10.1161/ATVBAHA.111.242818 | PMID = 22345594 }}</ref><ref name=pmid20852464>{{Cite journal  | last1 = Meetoo | first1 = D. | title = In too deep: understanding, detecting and managing DVT. | journal = Br J Nurs | volume = 19 | issue = 16 | pages = 1021-7 | month =  | year =  | doi = | PMID = 20852464 }}</ref>
*Immobility.
#Hypercoagulability.
*Pregnancy.
#Endothelial dysfunction/injury.
*Medications (e.g. OCPs).
#Stasis.
*Hypercoagulable states (memory device ''CALMSHAPES''):<ref>URL: [http://archinte.highwire.org/cgi/content/full/161/20/2433 http://archinte.highwire.org/cgi/content/full/161/20/2433]. Accessed on: 15 September 2010.</ref>
 
**Protein C deficiency.
Note:
**Antiphospholipid antibody syndrome (APLA).
*The triad has a limited practical use. Like many questions about mechanism, the greatest utility, might be pimping medical students and residents.
**Leiden factor V deficiency.
 
**Malignancy.
===Risks factors venous thromboembolism===
**Protein S deficiency.
A general mnemonic for hypercoagulable states ''PIANO'':<ref>URL: [http://www.usmle-forums.com/usmle-step-1-mnemonics/252-causes-hypercoagulable-states.html http://www.usmle-forums.com/usmle-step-1-mnemonics/252-causes-hypercoagulable-states.html]. Accessed on: 8 December 2011.</ref>
**Homocystinemia.
*[[pregnancy|'''P'''regnancy]].
**Antithrombin deficiency.
*'''I'''mmobility.
**Prothrombin G20210A.
*'''A'''ccidental injury.
**Excess factor VIII.  
*[[Nephrotic syndrome|'''N'''ephrotic syndrome]].
**Sticky platelet syndrome.
*[[Oral contraceptive pill|'''O'''ral contraceptive pills]].
 
Hypercoagulable states due to intrinsic causes (memory device ''CALM SHAPES''):<ref name=pmid11700155>{{cite journal |author=Thomas RH |title=Hypercoagulability syndromes |journal=Arch. Intern. Med. |volume=161 |issue=20 |pages=2433–9 |year=2001 |month=November |pmid=11700155 |doi= |url=http://archinte.highwire.org/cgi/content/full/161/20/2433}}</ref>
*Protein '''C''' deficiency.
*[[Antiphospholipid antibody syndrome|'''A'''ntiphospholipid antibody syndrome]] (APLA).
*'''L'''eiden factor V deficiency.
*'''M'''alignancy.
*Protein '''S''' deficiency.
*'''H'''omocystinemia.
*'''A'''ntithrombin III deficiency.
*'''P'''rothrombin G20210A.<ref name=omim176930>{{OMIM|176930}}</ref>
*'''E'''xcess factor VIII.  
*'''S'''ticky platelet syndrome.


==Gross (VTE)==
==Gross (VTE)==
Line 82: Line 101:
==Microscopic (VTE)==
==Microscopic (VTE)==
Features:
Features:
*Layers consisting of platelets and fibrin alternating with layers of RBCs; ''Lines of Zahn''.<ref name=Ref_PBoD8_124>{{Ref PBoD8|124}}</ref>
*Layers consisting of platelets and fibrin alternating with layers of RBCs - known as ''Lines of Zahn''.<ref name=Ref_PBoD8_124>{{Ref PBoD8|124}}</ref>
 
Note:
*Multiple laminations (layers), in general, suggest that clot was formed in a dynamic environment, i.e. in the context of blood flow.
 
===Images===
*www:
**[http://library.med.utah.edu/WebPath/ATHHTML/ATH031.html Lines of Zahn (utah.edu)].
**[http://pathhsw5m54.ucsf.edu/case9/image94.html Lines of Zahn (ucsf.edu)].
<gallery>
Image:Laminations_in_a_thrombus_-_low_mag.jpg | Laminated thrombus - low mag. (WC)
Image:Laminations_in_a_thrombus_-_high_mag.jpg | Laminated thrombus - high mag. (WC)
</gallery>
 
==Microscopic (fat embolism)==
Features:
*Fat in vessels.
 
Images:
*[http://library.med.utah.edu/WebPath/jpeg2/FOR001.jpg Fat embolism (med.utah.edu)].<ref>URL: [http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/fofrm.html http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/fofrm.html]. Accessed on: 6 December 2010.</ref>
 
==Microscopic (amniotic fluid)==
Features:<ref name=pmid13576364>{{Cite journal  | last1 = ATTWOOD | first1 = HD. | title = The histological diagnosis of amniotic-fluid embolism. | journal = J Pathol Bacteriol | volume = 76 | issue = 1 | pages = 211-5 | month = Jul | year = 1958 | doi =  | PMID = 13576364 }}</ref>
*Pulmonary vessels with fetal debris - particularly squamous cells.
 
Notes:
*Can easily be missed.<ref name=pmid9104942>{{Cite journal  | last1 = Kobayashi | first1 = H. | last2 = Ooi | first2 = H. | last3 = Hayakawa | first3 = H. | last4 = Arai | first4 = T. | last5 = Matsuda | first5 = Y. | last6 = Gotoh | first6 = K. | last7 = Tarao | first7 = T. | title = Histological diagnosis of amniotic fluid embolism by monoclonal antibody TKH-2 that recognizes NeuAc alpha 2-6GalNAc epitope. | journal = Hum Pathol | volume = 28 | issue = 4 | pages = 428-33 | month = Apr | year = 1997 | doi =  | PMID = 9104942 }}</ref>
*[[Alcian blue stain]] useful. (???)


Images:  
Images:
*[http://library.med.utah.edu/WebPath/ATHHTML/ATH031.html Lines of Zahn (utah.edu)].
<gallery>
*[http://pathhsw5m54.ucsf.edu/case9/image94.html Lines of Zahn (ucsf.edu)].
Image:Amniotic_fluid_embolism.jpg | Amniotic fluid embolism. (WC/Rosen)
</gallery>


==See also==
==See also==
*[[Pulmonary pathology]].
*[[Pulmonary pathology]].
*[[Cholesterol embolism]].
*[[Cerebral fat embolism]].
*[[Vascular thrombus]].
*[[Intimal sarcoma]].


==References==
==References==

Latest revision as of 17:21, 18 January 2024

Pulmonary embolism, abbreviated PE, is often on the differential in autopsies, as it is not easy to diagnose clinically. Pulmonary embolism is a non-specific term; it may refer to a number of things, including:

  • Pulmonary venous thromboembolism.
  • Pulmonary fat embolism.
  • Pulmonary foreign body embolism.
  • Pulmonary septic embolism.
  • Pulmonary bone marrow embolism.
  • Pulmonary tumour embolism.
  • Pulmonary amniotic fluid embolism.

PE usually refers to pulmonary venous thromboembolism, abbreviated VTE, if not otherwise specified.

General

  • Relatively uncommon ~ 1 in 1000 adults per year.[1]
  • Diagnosis in life dependent on strong clinical suspicion and radiology.

Clinical

  • Shortness of breath (dyspnea) - classic symptom.
  • Tachycardia.
  • Chest pain.
  • Findings associated with deep vein thrombosis.
    • Leg pain.
    • Leg swelling.

Notes:

  • Venous thrombosis OR~=12 for PE.[2]

Mechanism

The classic factors are given by Virchow's triad:[3][1]

  1. Hypercoagulability.
  2. Endothelial dysfunction/injury.
  3. Stasis.

Note:

  • The triad has a limited practical use. Like many questions about mechanism, the greatest utility, might be pimping medical students and residents.

Risks factors venous thromboembolism

A general mnemonic for hypercoagulable states PIANO:[4]

Hypercoagulable states due to intrinsic causes (memory device CALM SHAPES):[5]

  • Protein C deficiency.
  • Antiphospholipid antibody syndrome (APLA).
  • Leiden factor V deficiency.
  • Malignancy.
  • Protein S deficiency.
  • Homocystinemia.
  • Antithrombin III deficiency.
  • Prothrombin G20210A.[6]
  • Excess factor VIII.
  • Sticky platelet syndrome.

Gross (VTE)

Features:

  • Intravascular spaghetti (multiple cylindrical clots - from smaller vessels) with cream sauce (gray fibrin).
  • Leg swelling.
  • Lines of Zahn.[7]
    • Pale layers consisting of platelets and fibrin alternating with layers of RBCs; components layer during blood flow.

Notes:

  • Post-mortem thrombi: one (superior) yellow portion (called "chicken fat") and one (dependent) red portion (RBCs); components layer due to gravity.

Pre- and post-mortem clots

Feature/time Pre-mortem Post-mortem
Shininess dull shiny
Adherent to wall yes no
Colour gray dark purple or
bilayered red/yellow
Pressurized yes; "ejects itself" from lumen no; needs to be pulled-out
Consistency
-elastic modulus (E)
-fracture toughness (K) 		firm (high E)
brittle (low K) 		jello (low E)
elastic (high K)
Image - gross thrombus (pathguy.com),
thrombus (thrombosisadviser.com) 		coronary thrombus (luc.edu)[8]
Image - micro. pre- & post-mortem (elsevier.es)[9] thrombus (oxfordjournals.org),
thrombi (ucsf.edu)

Microscopic (VTE)

Features:

  • Layers consisting of platelets and fibrin alternating with layers of RBCs - known as Lines of Zahn.[7]

Note:

  • Multiple laminations (layers), in general, suggest that clot was formed in a dynamic environment, i.e. in the context of blood flow.

Images

  • Laminated thrombus - low mag. (WC)

  • Laminated thrombus - high mag. (WC)

Microscopic (fat embolism)

Features:

  • Fat in vessels.

Images:

Microscopic (amniotic fluid)

Features:[11]

  • Pulmonary vessels with fetal debris - particularly squamous cells.

Notes:

Images:

  • Amniotic fluid embolism. (WC/Rosen)

See also

References

  1. ↑ 1.0 1.1 Meetoo, D.. "In too deep: understanding, detecting and managing DVT.". Br J Nurs 19 (16): 1021-7. PMID 20852464.
  2. ↑ Reissig A, Haase U, Schulze E, Lehmann T, Kroegel C (July 2010). "[Diagnosis and therapy of pulmonary embolism prior to death]" (in German). Dtsch. Med. Wochenschr. 135 (30): 1477–83. doi:10.1055/s-0030-1262435. PMID 20648405.
  3. ↑ Reitsma, PH.; Versteeg, HH.; Middeldorp, S. (Mar 2012). "Mechanistic view of risk factors for venous thromboembolism.". Arterioscler Thromb Vasc Biol 32 (3): 563-8. doi:10.1161/ATVBAHA.111.242818. PMID 22345594.
  4. ↑ URL: http://www.usmle-forums.com/usmle-step-1-mnemonics/252-causes-hypercoagulable-states.html. Accessed on: 8 December 2011.
  5. ↑ Thomas RH (November 2001). "Hypercoagulability syndromes". Arch. Intern. Med. 161 (20): 2433–9. PMID 11700155. http://archinte.highwire.org/cgi/content/full/161/20/2433.
  6. ↑ Online 'Mendelian Inheritance in Man' (OMIM) 176930
  7. ↑ 7.0 7.1 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 124. ISBN 978-1416031215.
  8. ↑ URL: http://www.meddean.luc.edu/lumen/meded/mech/cases/case1/list.htm. Accessed on 8 October 2010.
  9. ↑ URL: http://www.elsevier.es/cardio_eng/ctl_servlet?_f=40&ident=13142654. Accessed on: 8 October 2010.
  10. ↑ URL: http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/fofrm.html. Accessed on: 6 December 2010.
  11. ↑ ATTWOOD, HD. (Jul 1958). "The histological diagnosis of amniotic-fluid embolism.". J Pathol Bacteriol 76 (1): 211-5. PMID 13576364.
  12. ↑ Kobayashi, H.; Ooi, H.; Hayakawa, H.; Arai, T.; Matsuda, Y.; Gotoh, K.; Tarao, T. (Apr 1997). "Histological diagnosis of amniotic fluid embolism by monoclonal antibody TKH-2 that recognizes NeuAc alpha 2-6GalNAc epitope.". Hum Pathol 28 (4): 428-33. PMID 9104942.
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