Pulmonary embolism
See Pulmonary embolism in pregnancy for pregnancy specific information.[1]
Background
Clinical Spectrum of Venous thromboembolism
- Deep venous thrombosis (uncomplicated)
- Phlegmasia alba dolens
- Phlegmasia cerulea dolens
- Venous gangrene
- Pulmonary embolism
- Isolated distal deep venous thrombosis
Only 40% of ambulatory ED patients with PE have concomitant DVT[2][3]
Pulmonary Embolism Categorization[4]
Massive: High-risk
Hemodynamically unstable with symptoms of shock
- ACCP 2016 CHEST Guidelines: Sustained hypotension ONLY criteria (systolic BP <90 for at least 15min or requiring inotropic support)
- Previous definitions (e.g. AHA 2011) include cardiac arrest/pulselessness or persistent profound bradycardia (HR <40 with signs of shock)
Submassive: Intermediate-risk
Right ventricular dysfunction (RVD) and/or myocardial necrosis in the absence of persistent hypotension or shock (SBP >90)[5]
- RV dysfunction
- RV dilation or dysfunction on TTE
- "D Sign" on bedside echo (LV takes on a "D" shape due to RV dilation)
- RV dysfunction on CT defined as RV/LV ratio >0.9[6]
- Elevation of BNP (>90)
- ECG findings of right heart strain (see diagnosis below)
- RV dilation or dysfunction on TTE
- Myocardial necrosis: Troponin I >0.4
Non-Massive: Low-risk
No hemodynamic compromise and no RV strain
Sub-Segmental
- Limited to the subsegmental pulmonary arteries
Clinical Features
Symptoms
According to the PIOPED II study, these are the most common presenting signs[7]
- Dyspnea at rest or with exertion (73%)
- Pleuritic chest pain (44%)
- Cough (37%)
- Orthopnea (28%)
- Calf or thigh pain and/or swelling (44%)
- Wheezing (21%)
- Hemoptysis (13%)
Signs
- Tachypnea (54%)
- Calf or thigh swelling, erythema, edema, tenderness, palpable cord (47%)
- Tachycardia (24%)
- Rales (18%)
- Decreased breath sounds (17%)
- Accentuated pulmonic component of the second heart sound (15%)
- JVD (14%)
- Fever (3%)
Differential Diagnosis
Chest pain
Critical
- Acute coronary syndromes (ACS)
- Aortic dissection
- Cardiac tamponade
- Coronary artery dissection
- Esophageal perforation (Boerhhaave's syndrome)
- Pulmonary embolism
- Tension pneumothorax
Emergent
- Cholecystitis
- Cocaine-associated chest pain
- Mediastinitis
- Myocardial rupture
- Myocarditis
- Pancreatitis
- Pericarditis
- Pneumothorax
Nonemergent
- Aortic stenosis
- Arthritis
- Asthma exacerbation
- Biliary colic
- Costochondritis
- Esophageal spasm
- Gastroesophageal reflux disease
- Herpes zoster / Postherpetic Neuralgia
- Hypertrophic cardiomyopathy
- Hyperventilation
- Mitral valve prolapse
- Panic attack
- Peptic ulcer disease
- Pleuritis
- Pneumomediastinum
- Pneumonia
- Rib fracture
- Stable angina
- Thoracic outlet syndrome
- Valvular heart disease
- Muscle sprain
- Psychologic / Somatic Chest Pain
- Spinal Root Compression
- Tumor
Acute dyspnea
Emergent
- Pulmonary
- Airway obstruction
- Anaphylaxis
- Angioedema
- Aspiration
- Asthma
- Cor pulmonale
- Inhalation exposure
- Noncardiogenic pulmonary edema
- Pneumonia
- Pneumocystis Pneumonia (PCP)
- Pulmonary embolism
- Pulmonary hypertension
- Tension pneumothorax
- Idiopathic pulmonary fibrosis acute exacerbation
- Cystic fibrosis exacerbation
- Cardiac
- Other Associated with Normal/↑ Respiratory Effort
- Other Associated with ↓ Respiratory Effort
Non-Emergent
- ALS
- Ascites
- Uncorrected ASD
- Congenital heart disease
- COPD exacerbation
- Fever
- Hyperventilation
- Interstitial lung disease
- Neoplasm
- Obesity
- Panic attack
- Pleural effusion
- Polymyositis
- Porphyria
- Pregnancy
- Rib fracture
- Spontaneous pneumothorax
- Thyroid Disease
- URI
Workup by Pretest Probability
See Pulmonary embolism in pregnancy for pregnancy specific information.[8]
Assessing Pretest Probability
Objective criteria (Geneva, Wells, etc.) is equal to gestalt in assessing pre-test probability[9] (ACEP Level B)
Pretest | - LR | Posttest | |
---|---|---|---|
Wells < 4 + PERC | 12% | 0.12 | 1.6% |
Wells < 4 + Neg Dimer | 12% | 0.01 | 0.14% |
Wells < 4 + AA Dimer | 12% | 0.06 | 0.81% |
Wells < 2 + PERC | 2% | 0.01 | 0.24% |
Wells < 2 + Neg Dimer | 2% | 0.06 | 0.02% |
Wells < 2 + AA Dimer | 2% | 0.12 | 0.12 |
Low Probability
D-dimer NPV is 99.5%[10]
- If low probability and PERC Rule negative, then no workup[9] (ACEP Level B)
- If low probability and PERC Rule positive, then d-dimer[9] (ACEP Level B)
- Avoid CT pulmonary angiography in low pretest probability patients that are either PERC rule negative or have a negative d-dimer (ACEP choosing wisely)
Moderate Probability
- D-dimer
- However, it is unclear whether d-dimer alone is sufficient to rule-out PE[9] (ACEP Level C)
High Probability
Consider anticoagulation before imaging!
Diagnosis
- ECG (sbnormal in 70% of PE patients[12])
- CXR (abnormal in 70%)
- Atelectasis is most common (esp >24 hrs after onset of symptoms)
- Pleural effusion
- Hampton's Hump
- Westermark's sign[15]
- Transthoracic echo
- May see signs of right heart strain (bowing of septum into LV; Aka D Sign)
- 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[16]
- Imaging
- CTA 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, LE vasc US, VQ, traditional pulmonary arteriography) prior to exclusion of VTE[9] (ACEP Level C)
- A negative d-dimer in combination with a negative CTA theoretically provides a post-test probability of VTE less than 1%
Bedside Ultrasound
- Ultrasound can help diagnosis in equivocal cases
- Assess for right ventricular strain (RVS) and McConnell's sign
- RVS is associated with statistically significant worse outcome[17]
Other Modalities
- 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[18]
Wells Criteria
Wells Score
Wells Criteria
Clinical Features | Points |
---|---|
Symptoms of DVT (leg swelling and pain with palpation) | 3.0 |
PE as likely as or more likely than an alternative diagnosis | 3.0 |
HR >100 bpm | 1.5 |
Immobilization for >3 consecutive days or surgery in the previous 4 weeks | 1.5 |
Previous DVT or PE | 1.5 |
Hemoptysis | 1.0 |
Malignancy (receiving treatment, treatment stopped within 6 mon, palliative care) | 1.0 |
Two Tier Wells Score
- Score 0-4 = PE Unlikely (12.1% incidence of PE)
- Check D-dimer
- If D-dimer positive then obtain CTPA or V/Q scan
- If D-dimer negative, no further workup needed (0.5% incidence of PE at 3 month follow up)
- Check D-dimer
- Score >4 = PE Likely (37.1% incidence of PE)
- Obtain CT Pulmonary Angiography or V/Q Scan
- New evidence suggests lower Wells Score with D-dimer <1000 ng/mL is effective at ruling out PE without imaging
Less common risks
- HIV (protein wasting nephropathy)
- Nephrotic Syndrome
- SLE with anti-cardiolipan Ab
- Exogenous hormones (specifically estrogen)
- Factor V Leiden
- Antithrombin III deficiency
- Protein C deficiency
- Protein S deficiency
- Hyperhomocysteinemia
Age Adjusted D-Dimer
Labs commonly report the test as fibrinogen equivalent units (FEUs) with the cutoff at 500 ng/mL and most studies used the FEU values for derivation or validation. If reported by the lab as a D-dimer unit (DDU) the cutoff is often 230 ng/mL. 2 FEUs equal 1 DDU.
- Age (years) x 10 ug/L for patients > 50 years of age
- Patient age 75 = age adjusted d-dimer of 750 ug/L
- If using a lab with a cutoff of 230 (DDU assay) then formula is Age x 5
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).
- The Feb. 2016 CHEST Guideline recommends clinical surveillance over anticoagultation for subsegmental PE with no proximal DVTat low risk for recurrent VTE based on level 2C evidence[19]
- LMWH SC
- 1st line for most hemodynamically stable patients
- Contraindicated in renal failure
- Enoxaparin 1mg/kg SC q12h
- Dalteparin 200 IU/kg SC q24h, max 18,000 IU
- Unfractionated Heparin
- 80 units/kg bolus; then 18 units/kg/hr
- Check PTT after 6hr; adjust infusion to maintain PTT at 1.5-2.5x control
- Benefit of Heparin is the short half life and easy ability to turn off the infusion. Consider
- Patients with morbid obesity or anasarca may have poor sc absorption with LMWH
- No need for renal dosing
- 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
- Dabigatran
- Rivaroxaban
- Apixaban
- Vit K antagonist - Coumadin
- 3-6 mo if time limited risk factor (post-op, trauma, estrogen use)
- 6 mo - life if idiopathic etiology or recurrent
- INR target 2.5
- Temporary hypercoagulable state for approx 5 days
- Initial dose is 5 mg PO
Thrombolysis
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[26]
Prognosis
The Pulmonary Embolism Severity Index (PESI)[27]
- PE patients with PESI class I or II seem safe to manage as outpatients.
Prognosis Variable | 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 |
Risk Class | 30-Day Mortality | 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
Thrombolytics for pulmonary embolism
- Clinical Page
- Research summary page: EBQ:Thrombolysis in Pulmonary Embolism Metanalysis
External Links
- MDCalc - Well's Criteria for Pulmonary Embolism
- MDCalc - PERC Rule for Pulmonary Embolism
- MDCalc - Geneva Score for Pulmonary Embolism
- MDCalc - PESI - Pulmonary Embolism Severity Index
References
- ↑ 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
- ↑ Righini M, Le GG, Aujesky D, et al. Diagnosis of pulmonary embolism by multidetector CT alone or combined with venous ultrasonography of the leg: a randomised non-inferiority trial. Lancet. 2008; 371(9621):1343-1352.
- ↑ Daniel KR, Jackson RE, Kline JA. Utility of the lower extremity venous ultrasound in the diagnosis and exclusion of pulmonary embolism in outpatients. Ann Emerg Med. 2000; 35(6):547-554.
- ↑ Jaff MR et al. Management of massive and submassive pulmonary embolism, ileofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the American Heart Association. Circulation. 2011 Apr 26;123(16):1788-830. doi: 10.1161/CIR.0b013e318214914f. Epub 2011 Mar 21
- ↑ Martin C et al. Systemic thrombolysis for pulmonary embolism: a review. P T. 2016 Dec; 41(12):770-775
- ↑ Becattini C et al. Multidetector computed tomography for acute pulmonary embolism: diagnosis and risk stratification in a single test. Eur Heart J. 2011 Jul;32(13):1657-63. doi: 10.1093/eurheartj/ehr108. Epub 2011 Apr 18.
- ↑ Stein PD et al. Clinical characteristics of patients with acute pulmonary embolism: data from PIOPED II. Am J Med. 2007;120(10):871.
- ↑ 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
- ↑ 9.0 9.1 9.2 9.3 9.4 ACEP Clinical Policy for Pulmonary Embolism full text
- ↑ 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
- ↑ http://www.thepocusatlas.com/right-ventricle
- ↑ 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.
- ↑ 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
- ↑ 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
- ↑ 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. full text
- ↑ 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.
- ↑ 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.
- ↑ 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
- ↑ Kearon, Clive, et al. "Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report." Chest (2016).[fulltext]
- ↑ 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.
- ↑ 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 DVTand EINSTEIN PE studies [abstract 20]. Presented at: 54th Annual Meeting and Exposition of the American Society of Hematology; December 8, 2012; Atlanta, Ga.
- ↑ 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.
- ↑ 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.
- ↑ 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.