Ver el código de «Pulmonary embolism»

''See [[Pulmonary embolism in pregnancy]] for pregnancy specific information.''<ref>D-Dimer Concentrations in Normal Pregnancy: New Diagnostic Thresholds Are Needed. Kline et all. Clinical Chemistry May 2005 vol. 51 no. 5 825-829 http://www.clinchem.org/content/51/5/825.long</ref>

==Background==
{{Venous thromboembolism types}}

{{PE types}}

=== Epidemiology ===
* The best estimates indicate that 350,000 to 600,000 Americans each year suffer from DVT and PE<ref>Mozaffarien D et al.  Heart disease and stroke statistics - 2015 report from the American Heart Association. Circulation. 2015;131:d29-e322</ref>
* Survival<ref>U. S. Department of Health and Human Services. www.ncbi.nlm.nih.gov/blooks/NBK44178. The surgeon general's call to prevent deep vein thrombosis and pulmonary embolism.  2008</ref>
**PE is the 3rd leading cause of cardiovascular morbidity and mortality
**At least 100,000 deaths per year may be directly or indirectly related to DVT and PE
**For almost one quarter of PE patients, the initial clinical presentation is sudden death
**PE is an independent predictor of reduced survival for ≤3 months
**One of the leading causes of out-of-hospital, non-trauma related sudden deaths <ref>Tintinalli, J. E. (2016). Venous Thromboembolism In J.E. Tintinali (8th Ed.), Tintinalli's Emergency Medicine: A Comprehensive Study Guide  (pp. 389-390). New York, New York: McGraw Hill Education</ref>

==Clinical Features==
{{PE clinical presentation}}

==Differential Diagnosis==
{{Chest Pain DDX}}
{{SOB DDX}}

==Workup==
===Assessing Pretest Probability===
*''Objective criteria (Geneva, Wells, etc.) is equal to gestalt in assessing pre-test probability<ref name="ACEP">ACEP Clinical Policy for Pulmonary Embolism [http://www.acep.org/Content.aspx?id=80787/ full text]</ref> (ACEP Level B)''
*Initial Wells study and prospective validation <ref> Wolf SJ, et al. Prospective validation of Wells Criteria in the evaluation of patients with suspected pulmonary embolism. Ann Emerg Med. 2004 Nov;44(5):503-10</ref> used a three tier system (low, intermediate, high) for pretest probability
*The larger Christopher Study group used a larger sample size to derive the simplified dichotomized model below<ref>van Belle A et al. Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography. JAMA. 2006;295(2):172-179. doi:10.1001/jama.295.2.172</ref>

{{Wells Score}}

===Low-Probability Testing in the ED===
*''[[PERC Rule]] negative'', then no further workup<ref name="ACEP" /> (ACEP Level B)
**Avoid CT pulmonary angiography in low pretest probability patients that are either PERC rule negative or have a negative d-dimer ([[Choosing wisely ACEP|ACEP choosing wisely]])
**D-dimer NPV is 99.5%<ref>Wells PS, Anderson DR, Rodger M, et al. Excluding pulmonary embolism at the bedside without diagnostic imaging: management of patients with suspected pulmonary embolism presenting to the emergency department by using a simple</ref>
*''[[PERC Rule]] positive'', then [[D-dimer]] (see Moderate-Probability Testing below)<ref name="ACEP" />  (ACEP Level B)
**Can also consider using Wells score as above to determine further testing


====Less common risk factors====
*HIV (protein wasting nephropathy)
*[[Nephrotic Syndrome]]
*[[SLE]] with anti-cardiolipin Ab
*Exogenous hormones (specifically estrogen)
*homozygous Factor V Leiden
*Antithrombin III deficiency
*Protein C deficiency
*Protein S deficiency
*Hyperhomocysteinemia

===ACCP 2012 Guidelines: Initial Management While Awaiting Workup<ref>ACCP 9th Edition of the Antithrombotic Therapy Guidelines: Kearon C et al. Antithrombotic therapy for VTE disease. Chest. 2012;141:e419s – e494s. doi: 10.1378/chest.11-2301.</ref>===
{| class="wikitable"
!Clinical suspicion !! Management
|-
| Low || Do not treat with anticoagulation while awaiting diagnostic test results
|-
| Medium || Treat with parenteral anticoagulation if the results of diagnostic tests are expected to be delayed ≥ 4 hours
|-
| High || Treat with parenteral anticoagulation while awaiting diagnostic test results
|-
|}

==Diagnosis==
[[File:SaddlePE.png|thumb|A large pulmonary embolism at the bifurcation of the pulmonary artery (saddle embolism).]]
===Definitive Diagnostic Imaging===
*CTA Chest if GFR >60
*V/Q if GFR <60
**Will be nondiagnostic if patient has effusion, pneumonia, or other airspace disease
*If imaging negative, perform additional diagnostic testing (eg, D-dimer, lower extremity vasc US, VQ, traditional pulmonary arteriography) prior to exclusion of VTE<ref name="ACEP" /> (ACEP Level C)
**A negative d-dimer in combination with a negative CTA theoretically provides a post-test probability of VTE less than 1%

===Other Possible Diagnostic Findings===
[[File:dsign.gif|thumb|D Sign<ref>http://www.thepocusatlas.com/right-ventricle</ref>]]
[[File:Hamptons.jpg|thumb|Hampton's Hump]]
*[[ECG]] (abnormal in 70% of [[PE]] patients<ref>Marchick, MR et al. 12-lead ECG findings of pulmonary hypertension occur more frequently in emergency department patients with pulmonary embolism than in patients without pulmonary embolism. Ann Emerg Med. 2010 Apr;55(4):331-5.</ref>)
**Sinus tachycardia is most common finding
**T-wave inversion in anterior/septal leads + inferior leads<ref>Kosuge M, Kimura K, Ishikawa T, et al. Electrocardiographic differentiation between acute pulmonary embolism and acute coronary syndromes on the basis of negative T waves. Am J Cardiol 2007; 99: 817–821</ref>
**Nonspecific ST changes, S1Q3T3 (develops due to strain on RV)
**RBBB or new incomplete RBBB.<ref>Shopo, JD et al. Findings from 12-lead electrocardiography that predict circulatory shock in pulmonary embolism; a systematic review and meta-analysis. Acad Emerg Med. 2015 Oct;22(10):1127-37</ref>
**New right axis deviation
**Atrial fibrillation
*[[CXR]] (abnormal in 70%)
**Atelectasis is most common (esp >24 hrs after onset of symptoms)
**Pleural effusion
**Hampton's Hump 
**Westermark's sign<ref>Sreenivasan S, Bennett S, Parfitt VJ. Images in cardiovascular medicine. Westermark's and Palla's signs in acute pulmonary embolism. Circulation. 2007 Feb 27;115(8):e211. [http://circ.ahajournals.org/content/115/8/e211.long full text]</ref> 
*Formal transthoracic echo or [[Cardiac ultrasound|bedside cardiac ultrasound]]
**Can help diagnosis in equivocal cases
**May see signs of right heart strain (bowing of septum into LV; Aka D Sign)
***Right ventricular strain is associated with statistically significant worse outcome<ref>Taylor, RA, et al. Point-of-care focused cardiac ultrasound for prediction of pulmonary embolism adverse outcomes. The Journal of Emergency Medicine. 2013; 45(3):392–399.</ref>
**McConnel's sign (akinesis of RV base/free wall with sparing of apex)
**Lateral right ventricular wall diameter of <5mm is suggestive of acute pulmonary hypertension while >5mm is suggestive of chronic pulmonary hypertension<ref>Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010; 23(7):685-713.</ref>
*SPECT 
**Combination of noncontrast CT chest with V/Q scan
**Avoidance of contrast for patients with renal injury
**As sensitive as CTPA and more sensitive than planar V/Q scanning<ref> Lu Y, Lorenzoni A, Fox JJ, Rademaker J, Vander Els N, Grewal RK, Strauss HW, Schöder H. Noncontrast perfusion single-photon emission CT/CT scanning: a new test for the expedited, high-accuracy diagnosis of acute pulmonary embolism. Chest. 2014 May;145(5):1079-88</ref>

==Management==
===Supportive care===
*Give [[IVF]] as necessary to increase preload while frequently assessing volume status

===Anticoagulation===
*Treatment options include any of the following anticoagulations which are indicated for all patients with confirmed [[PE]] or high clinical suspicion (do not wait for imaging).
*Clinical surveillance over anticoagultation for subsegmental [[PE]] with no proximal [[DVT]] at low risk for recurrent VTE ([[EBQ:Evidence_Levels|Level 2C]] evidence)<ref>Kearon, Clive, et al. "Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report." Chest (2016).[[http://www.cercp.org/images/stories/recursos/articulos_docs_interes/guia_tto_antitrombotico_tv_2016.pdf fulltext]]</ref>

{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Name'''
| align="center" style="background:#f0f0f0;"|'''[[LMWH]] SC'''
| align="center" style="background:#f0f0f0;"|'''[[Unfractionated Heparin]]'''
| align="center" style="background:#f0f0f0;"|'''[[Dabigatran]]'''
| align="center" style="background:#f0f0f0;"|'''[[Rivaroxaban]]'''
| align="center" style="background:#f0f0f0;"|'''[[Apixaban]]'''
| align="center" style="background:#f0f0f0;"|'''[[Coumadin]]'''
|-
|'''Initial Dose'''
||
*[[Enoxaparin]] 1mg/kg SC q12h 
*[[Dalteparin]] 200 IU/kg SC q24h, max 18,000 IU
||
*80 units/kg bolus; then 18 units/kg/hr
||
||
||
||
*5 mg PO
|-
| '''Benefits'''
||
*1st line for most hemodynamically stable patients
||
*Short half life and easy ability to turn off the infusion. 
*The prefered anticoagulation if thrombolysis is being considered or if there is a bleeding risk or trauma and anticoagulation will need to be emergently discontinued 
*No need for renal dosing 
||
*Noninferior to warfarin in reducing [[DVT]] and PE <ref>Schulman S, Kearon C, Kakkar AK, et al. Dabigatran versus warfarin in the treatment of acute venous thromboembolism. N Engl J Med. 2009; 361(24):2342-52. Schulman S, Kakkar AK, Goldhaber SZ, et al. Treatment of acute venous thromboembolism with dabigatran or warfarin and pooled analysis. Circulation. 2014; 129(7):764-72.</ref>
||
*Associated with less bleeding, particularly in elderly patients and those with moderate renal impairment compared to standard treatments <ref>Hughes S. Rivaroxaban Stands up to standard anticoagulation for VTE treatment. Medscape Medical News. December 13, 2012.Buller HR, on behalf of the EINSTEIN Investigators. Oral rivaroxaban for the treatment of symptomatic venous thromboembolism: a pooled analysis of the EINSTEIN [[DVT]] and EINSTEIN [[PE]] studies [abstract 20]. Presented at: 54th Annual Meeting and Exposition of the American Society of Hematology; December 8, 2012; Atlanta, Ga.</ref>
||
*Studies show 16% reduction in VTE related death compared to standard therapy <ref>Agnelli G, Buller HR, Cohen A, et al. Oral apixaban for the treatment of acute venous thromboembolism. N Engl J Med. 2013; 369(9):799-808.Agnelli G, Buller HR, Cohen A, Curto M, Gallus AS, Johnson M, et al. Apixaban for extended treatment of venous thromboembolism. N Engl J Med. 2013; 368(8):699-708.</ref>
||
|-
| '''Contraindications'''
||
*Contraindicated in renal failure 
*Patients with morbid obesity or anasarca may have poor absorption
||
||
||
||
||
*Temporary hypercoagulable state for approx 5 days
|-
| '''Comments'''
||
||
*Check PTT after 6hr; adjust infusion to maintain PTT at 1.5-2.5x control
||
||
||
||
*INR target 2.5 
*Duration 
**3-6 mo, if time limited risk factor (post-op, trauma, estrogen use) 
**6 mo to life, if idiopathic etiology or recurrent
|}

===Thrombolysis===
*See [[Thrombolysis for PE]]
===[[IVC Filter]]===
*Indications
**anticoagulation contraindicated in patient with PE
**failure to attain adequate anticoagulation during treatment

==Disposition==
*Patients with significant clot burden generally require admission for anticoagulation
*Consider discharge in low risk patients with peripheral PE<ref>Vinson DR, Zehtabchi S, Yealy DM. Can selected patients with newly diagnosed pulmonary embolism be safely treated without hospitalization? A systematic review. Ann Emerg Med. 2012; 60:651-662.</ref>
*Consider calculating HESTIA criteria for treatment of outpatient PE<ref>Zondag et al. Hestia criteria can discriminate high- from low-risk patients with pulmonary embolism. European Respiratory Journal. 2013; 41:588-592.</ref>

==Prognosis==
The Pulmonary Embolism Severity Index (PESI)<ref>Aujesky D, Obrosky DS, Stone RA, et al. Derivation and validation of a prognostic model for pulmonary embolism. Am J Respir Crit Care Med. 2005;172:1041-1046.</ref>
*PE patients with PESI class I or II seem safe to manage as outpatients.
{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Prognosis Variable'''
| align="center" style="background:#f0f0f0;"|'''Points Assigned'''
|-
| '''Demographics'''||
|-
| Age||+Age in years
|-
| Male||+10
|-
| '''Comorbid Conditions'''||
|-
| Cancer||+30
|-
| Heart Failure||+10
|-
| Chronic Lung Diseae||+10
|-
| '''Clincal Findings'''||
|-
| Pulse >110 b/min||+20
|-
| sBP < 100||+30
|-
| RR > 30||+20
|-
| Temp <36 C||+20
|-
| AMS||+60
|-
| Art O2 Saturation <90%||+20
|-
|}

{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Risk Class'''
| align="center" style="background:#f0f0f0;"|'''30-Day Mortality'''
| align="center" style="background:#f0f0f0;"|'''Total Point Score'''
|-
| I||1.60%||<65
|-
| II||3.50%||66-85
|-
| III||7.10%||86-105
|-
| IV||11.40%||106-125
|-
| V||23.90%||>125
|-
|}

==See Also==
*[[Pulmonary Embolism in Pregnancy]]
*[[IVC Filter]]
*[[Cardiac ultrasound]]
{{Thrombolysis Submassive PE Trials}}

==External Links==
*[http://www.mdcalc.com/wells-criteria-for-pulmonary-embolism-pe/ MDCalc - Well's Criteria for Pulmonary Embolism]
*[http://www.mdcalc.com/perc-rule-for-pulmonary-embolism/ MDCalc - PERC Rule for Pulmonary Embolism]
*[http://www.mdcalc.com/geneva-score-revised-for-pulmonary-embolism/ MDCalc - Geneva Score for Pulmonary Embolism]
*[http://www.mdcalc.com/pulmonary-embolism-severity-index-pesi/  MDCalc - PESI - Pulmonary Embolism Severity Index]
*[https://www.mdcalc.com/hestia-criteria-outpatient-pulmonary-embolism-treatment#evidence/ MDCalc - Hestia Criteria for Pulmonary Embolism]

==References==
{{Reflist|2}}

[[Category:Cardiology]]
[[Category:Pulmonary]]
[[Category:Vascular]]