Pulmonary embolism assessment of clinical probability and risk scores: Difference between revisions
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:* Score <2.0 - Low probability (~15%). | :* Score <2.0 - Low probability (~15%). | ||
* | * The '''''modified extended version''''' of the Wells score has been proposed.<ref name="pmid10739372">{{cite journal |author=Sanson BJ, Lijmer JG, Mac Gillavry MR, Turkstra F, Prins MH, Büller HR |title=Comparison of a clinical probability estimate and two clinical models in patients with suspected pulmonary embolism. ANTELOPE-Study Group |journal=Thromb. Haemost. |volume=83 |issue=2 |pages=199-203 |year=2000 |pmid=10739372}}</ref> | ||
* An alternate dichotomous interpretation is:<ref>{{Cite journal | doi = 10.1136/bmj.e6564 | issn = 1756-1833 | volume = 345 | issue = oct04 2 | pages = e6564-e6564 | last = Geersing | first = G.-J. | coauthors = P. M. G. Erkens, W. A. M. Lucassen, H. R. Buller, H. t. Cate, A. W. Hoes, K. G. M. Moons, M. H. Prins, R. Oudega, H. C. P. M. van Weert, H. E. J. H. Stoffers | title = Safe exclusion of pulmonary embolism using the Wells rule and qualitative D-dimer testing in primary care: prospective cohort study | journal = BMJ | |||
| accessdate = 2012-10-05 | date = 2012-10-04 | url = http://www.bmj.com/content/345/bmj.e6564?etoc= | |||
}}</ref><ref name="pmid10744147"/><ref name="pmid16403929"/><ref name="pmid18165667"/> | |||
:* Score > 4 - PE likely. Consider diagnostic imaging. | |||
:* Score 4 or less - PE unlikely. Consider [[Pulmonary embolism D-dimer|D-dimer]] to rule out PE. | |||
* A simplified Wells criteria has been proposed<ref name="pmid18217159"/>, according to which all the 7 risk variables (table) are assigned 1 point each. A score ≤ 1 is categorized as unlikely to be PE. This score needs further validation in prospective studies. | * A simplified Wells criteria has been proposed<ref name="pmid18217159"/>, according to which all the 7 risk variables (table) are assigned 1 point each. A score ≤ 1 is categorized as unlikely to be PE. This score needs further validation in prospective studies. | ||
Revision as of 13:48, 5 October 2012
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Pulmonary Embolism Microchapters |
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Pulmonary Embolism Assessment of Probability of Subsequent VTE and Risk Scores |
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Editor(s)-In-Chief: The APEX Trial Investigators, C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Overview
The diagnosis of pulmonary embolism is based on clinical evaluation in conjunction with imaging modalities. Despite their individual sensitivities and specificities, studies have demonstrated that a combination of both these variables may help to discriminate suspected patients depending on their risk of developing pulmonary embolism and offer immediate management which is life-saving.
Pretest Probability
The diagnosis of PE is based primarily on the clinical evaluation combined with diagnostic modalities such as spiral CT, V/Q scan, use of the D-dimer and lower extremity ultrasound.
Although, the clinical pretest probability has shown to be fairly accurate,[1] the lack of validation has led to the use of a combination of both: clinical and diagnostic variables to predict the pretest probability that aids in the immediate management of high-risk patients.
Supportive trial data
- The Prospective Investigation On Pulmonary Embolism Diagnosis (PIOPED) investigators demonstrated that all patients with or without pulmonary embolism had abnormal V/Q scans of high, intermediate, or low probability (sensitivity, 98%; specificity, 10%). Furthermore, of the 116 patients with high-probability scans and definitive angiograms, only 88% had pulmonary embolism. On the contrary, only a minority of patients with pulmonary embolism demonstrated high-probability scans (sensitivity, 41%; specificity, 97%). Similarly, of the 322 patients with intermediate-probability scans and definitive angiograms, only 33% had pulmonary embolism. Despite these contrast findings, classification of patients based on clinical probability was fairly accurate and that with increasing clinical probability, an increase in PE prevalence was also observed. However, majority of these patients demonstrated low to moderate clinical probability which required no further intervention.[1]
- Another prospective multicentre outcome study by Musset et al, demonstrated that with-holding anticoagulation in patients with low or intermediate clinical probability and negative spiral CT and ultrasonagraphy was safe. Of the 1041 patients enrolled in the study, 525 were assessed as having low or intermediate clinical probability and 507 were not treated with anticoagulation. During a 3-month follow-up, only 9 patients experienced venous thromboembolism (1.8% [0.8-3.3]) and the diagnostic strategy proved inconclusive in 95 (9.1%) patients.[2][3]
Clinical Prediction Rules
Clinical prediction rule is a type of medical research study in which the researchers try to identify the best combination of medical sign, symptoms, and other findings to predict the probability of a specific disease or outcome.[4] Clinical prediction rules for PE include: the Wells score, the Geneva score and the PE rule-out criteria. Its noteworthy that the use of any clinical prediction rule is associated with reduction in recurrent thromboembolism.[5]
Wells Score
Wells score is a simple and most commonly used clinical risk prediction tool to evaluate the need for further testing in patients suspected to have pulmonary embolism.[6] and has undergo modifications since.[7][8][9]
| Variable | Wells[8] |
|---|---|
| Clinically suspected DVT (leg swelling, pain with palpation) | 3.0 |
| Alternative diagnosis is less likely than PE | 3.0 |
| Immobilization/surgery in previous four weeks | 1.5 |
| Previous history of DVT or PE | 1.5 |
| Tachycardia (heart rate more than 100 bpm) | 1.5 |
| Malignancy (treatment for within 6 months, palliative) | 1.0 |
| Hemoptysis | 1.0 |
Wells criteria [8][9]
- The following scoring system is used for assessment of risk[10] and need for further testing with D-dimer or CT scan:
- Score >6.0 - High probability (~59%).
- Score 2.0 to 6.0 - Moderate probability (~29%).
- Score <2.0 - Low probability (~15%).
- The modified extended version of the Wells score has been proposed.[11]
- Score > 4 - PE likely. Consider diagnostic imaging.
- Score 4 or less - PE unlikely. Consider D-dimer to rule out PE.
- A simplified Wells criteria has been proposed[15], according to which all the 7 risk variables (table) are assigned 1 point each. A score ≤ 1 is categorized as unlikely to be PE. This score needs further validation in prospective studies.
Geneva Score[16]
- The Geneva score is a clinical prediction rule used to determine the pre-test probability of pulmonary embolism based on the patient's risk factors and clinical findings.
- The Geneva score has shown to be fairly accurate as the Wells score, and is less reliant on the physicians clinical judgement.[17]
- The Geneva score has been revised and simplified from its original version and has shown to have the same diagnostic utility as the original score.[18]
Original Geneva Score
Variables:
The original Geneva score is calculated using 7 risk factors and clinical variables:
| Variable | Score |
|---|---|
| Age | |
| 60–79 years | 1.0 |
| 80+ years | 2.0 |
| Previous venous thromboembolism | |
| History of prior DVT or PE | 2.0 |
| Previous surgery | |
| Recent surgery within 4 weeks | 3.0 |
| Heart rate | |
| Heart rate >100 beats per minute | 1.0 |
| PaCO2 (partial pressure of CO2 in arterial blood) | |
| <35mmHg | 2.0 |
| 35-39mmHg | 1.0 |
| PaO2 (partial pressure of O2 in arterial blood) | |
| <49mmHg | 4.0 |
| 49-59mmHg | 3.0 |
| 60-71mmHg | 2.0 |
| 72-82mmHg | 1.0 |
| Chest X-ray findings | |
| Band atelectasis | 1.0 |
| Elevation of hemidiaphragm | 1.0 |
Interpretation:
The score obtained correlates to the probability of the patient suffering from pulmonary embolism (the lower the score, the lower the probability).
- Score < 5 points - low probability of PE.
- Score 5 to 8 points - moderate probability of PE.
- Score > 8 points - high probability of PE.
Revised Geneva Score
Recently in 2006, the revised Geneva score was introduced with a more standardized, sustained internal and external validation that may be used for the prediction of pulmonary embolism.[19] This simplified scoring system has shown to be as effective as the Wells score.[20]
Variables:
The revised score uses 8 parameters, excluding the assessment of arterial blood gas sample for the diagnosis of PE.
| Variable | Score |
|---|---|
| Age 65 years or over | 1.0 |
| Previous history of DVT or PE | 3.0 |
| Surgery or fracture within 1 month | 2.0 |
| Active malignant condition | 2.0 |
| Unilateral lower limb pain | 3.0 |
| Haemoptysis | 2.0 |
| Heart rate 75 to 94 beats per minute | 3.0 |
| Heart rate 95 or more beats per minute | 5.0 |
| Pain on deep palpation of lower limb and unilateral edema | 4.0 |
Interpretation:
The score obtained correlates to probability of PE and is summarized below:
- Score 0 to 3 points - lower probability (8%).
- Score 4 to 10 points - intermediate probability (28%).
- Score 11 points or more - higher probability (74%).
Simplified Geneva Score[18]
The simplified scoring system replaced the weighted scores for each parameter with a 1 point score for each parameter present, to reduce the likelihood of error when the score is used in clinical settings. The simplified Geneva score does not lead to a decrease in diagnostic utility in evaluating patients for a PE when compared to previous Geneva scores.
Variables:
| Variable | Score |
|---|---|
| Age >65 | 1.0 |
| Previous history of DVT or PE | 1.0 |
| Surgery or fracture within 1 month | 1.0 |
| Active malignancy | 1.0 |
| Unilateral lower limb pain | 1.0 |
| Hemoptysis | 1.0 |
| Pain on deep vein palpation of lower limb and unilateral edema | 1.0 |
| Heart rate 75 to 94 bpm | 1.0 |
| Heart rate greater than 94 bpm* | +1 |
| * Heart rates of 75 to 94 bpm receive 1 point, while heart rates higher than 94bpm receive a further point (i.e. 2 points in total) | |
Interpretation:
Decreased likelihood of developing PE if the score is 2 or below.
PE Rule-out Criteria (PERC)
- The Pulmonary Embolism Rule-out Criteria, or PERC rule, helps to evaluate patients in whom pulmonary embolism is suspected, but is unlikely.
- Unlike the Wells Score and Geneva score, which are clinical prediction rules intended to risk stratify patients with suspected PE, the PERC rule is designed to rule out the risk of PE in low-risk patients stratified clinically by the physicians; hence, to prevent unnecessary diagnostic testing in this patient population.[21]
- In 2008, Kline et al, demonstrated that the PERC rule had a sensitivity of 97.4%, specificity of 21.9% and a false negative rate of 1.0% when used as a diagnostic test. The study further concluded that among patients with low suspicion for PE, a negative PERC rule reduced the probability of VTE to below 2% and in about 20% of outpatients with suspected PE.[22] On the similar lines, among the low pretest probability population, Wolf et al, demonstrated that the use of PERC-approach had a high negative predictive value and sensitivity, but a low positive predictive value and specificity.[21] On the contrary, among patients with a higher prevalence of PE (>20%), the PERC based approach has shown to have significantly poor predictive value.[23]
| Variables |
|---|
| Age less than 50 years |
| Hemoptysis |
| Estrogen use |
| Prior history of DVT or PE |
| Unilateral leg swelling |
| Surgery or trauma requiring hospitalization within the past four weeks |
| Heart rate less than 100 bpm |
| Oxyhemoglobin saturation ≥95 percent |
Interpretation:
To rule-out pulmonary embolism based on PERC rule, the answer to every variable mentioned above should be No.
Summary of PE Clinical Probability based on Clinical Prediction Rules
| Clinical Prediction Rules | Clinical Probability of PE | ||
| Low (%) | Moderate (%) | High (%) | |
| Empirical[11][16][1] | 10 | 31 | 61 |
| Extended Wells Score[11][9][7] | 4 | 30 | 68 |
| Simplified Wells Score[11][8][24] | 15 | 29 | 59 |
| Original Geneva Score[16][24] | 11 | 38 | 79 |
| Revised Geneva Score[19] | 8 | 29 | 74 |
| “ |
Based on pooled study data. Adapted from Recommendations of The PIOPED II Investigators.[25] |
” |
ESC Guideline Recommendations [26]
Suspected Non High-risk PE Patients
| “ |
Class I1. In non-high-risk PE, basing the diagnostic strategy on clinical probability assessed either implicitly or using a validated prediction rule is recommended. (Level of Evidence: A) 2. The use of validated criteria for diagnosing PE is recommended. Validated criteria according to clinical probability of PE (low, intermediate or high) are detailed below. (Level of Evidence: B) |
” |
Exclusion Criteria for PE
| Diagnostic Criteria | Clinical Probability of PE | ||
| Low | Intermediate | High | |
| Normal pulmonary angiogram. | + | + | + |
| D-dimer: Negative result, highly sensitive assay. | + | + | - |
| D-dimer: Negative result, moderately sensitive assay. | + | - | - |
| V/Q Scan: Normal lung scan. | + | + | + |
| V/Q Scan: Non-diagnostic lung scana. | + | - | - |
| V/Q Scan: Non-diagnostic lung scana and negative proximal compression venous ultrasonography. | + | + | ± |
| Chest CT: Normal single-detector CT and negative proximal compression venous ultrasonography. | + | + | ± |
| Chest CT: Normal multi-detector CT alone. | + | + | ± |
Confirmation of PE
| Diagnostic Criteria | Clinical Probability of PE | ||
| Low | Intermediate | High | |
| Pulmonary angiogram showing PE. | + | + | + |
| High-probability V/Q Scan. | ± | + | + |
| Compression venous ultrasonography showing proximal DVT. | + | + | + |
| Chest CT: Single or multi-detector helical CT showing PE (at least segmental). | ± | + | + |
| Chest CT: Single or multi-detector helical CT showing sub-segmental PE. | ± | ± | ± |
alow or intermediate probability lung scan according to the PIOPED classification.
| + | Valid Criteria: No further testing required. |
| - | Invalid Criteria: Further testing necessary. |
| + | Controversial Criteria: Further testing to be considered. |
| “ |
Adapted from 2008 ESC guidelines on the diagnosis and management of acute pulmonary embolism. |
” |
Guideline Resources
Guidelines on the diagnosis and management of acute pulmonary embolism. The Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology[26]
References
- ↑ 1.0 1.1 1.2 "Value of the ventilation/perfusion scan in acute pulmonary embolism. Results of the prospective investigation of pulmonary embolism diagnosis (PIOPED). The PIOPED Investigators". JAMA : the Journal of the American Medical Association. 263 (20): 2753–9. 1990. PMID 2332918.
|access-date=requires|url=(help) - ↑ Musset D, Parent F, Meyer G, Maître S, Girard P, Leroyer C, Revel MP, Carette MF, Laurent M, Charbonnier B, Laurent F, Mal H, Nonent M, Lancar R, Grenier P, Simonneau G (2002). "Diagnostic strategy for patients with suspected pulmonary embolism: a prospective multicentre outcome study". Lancet. 360 (9349): 1914–20. doi:10.1016/S0140-6736(02)11914-3. PMID 12493257. Retrieved 2012-04-26. Unknown parameter
|month=ignored (help) - ↑ Perrier A, Miron MJ, Desmarais S, de Moerloose P, Slosman D, Didier D, Unger PF, Junod A, Patenaude JV, Bounameaux H (2000). "Using clinical evaluation and lung scan to rule out suspected pulmonary embolism: Is it a valid option in patients with normal results of lower-limb venous compression ultrasonography?". Archives of Internal Medicine. 160 (4): 512–6. PMID 10695691. Retrieved 2012-04-26. Unknown parameter
|month=ignored (help) - ↑ McGinn TG, Guyatt GH, Wyer PC, Naylor CD, Stiell IG, Richardson WS (2000). "Users' guides to the medical literature: XXII: how to use articles about clinical decision rules. Evidence-Based Medicine Working Group". JAMA : the Journal of the American Medical Association. 284 (1): 79–84. PMID 10872017. Retrieved 2012-04-26. Unknown parameter
|month=ignored (help) - ↑ Roy PM, Meyer G, Vielle B, Le Gall C, Verschuren F, Carpentier F, Leveau P, Furber A (2006). "Appropriateness of diagnostic management and outcomes of suspected pulmonary embolism". Ann. Intern. Med. 144 (3): 157–64. PMID 16461959.
- ↑ Wells PS, Hirsh J, Anderson DR, Lensing AW, Foster G, Kearon C, Weitz J, D'Ovidio R, Cogo A, Prandoni P (1995). "Accuracy of clinical assessment of deep-vein thrombosis". Lancet. 345 (8961): 1326–30. PMID 7752753. Unknown parameter
|month=ignored (help);|access-date=requires|url=(help) - ↑ 7.0 7.1 Wells PS, Ginsberg JS, Anderson DR, Kearon C, Gent M, Turpie AG, Bormanis J, Weitz J, Chamberlain M, Bowie D, Barnes D, Hirsh J (1998). "Use of a clinical model for safe management of patients with suspected pulmonary embolism". Ann Intern Med. 129 (12): 997–1005. PMID 9867786.
- ↑ 8.0 8.1 8.2 8.3 8.4 Wells P, Anderson D, Rodger M, Ginsberg J, Kearon C, Gent M, Turpie A, Bormanis J, Weitz J, Chamberlain M, Bowie D, Barnes D, Hirsh J (2000). "Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer". Thromb Haemost. 83 (3): 416–20. PMID 10744147.
- ↑ 9.0 9.1 9.2 Wells PS, Anderson DR, Rodger M, Stiell I, Dreyer JF, Barnes D, Forgie M, Kovacs G, Ward J, Kovacs MJ (2001). "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 clinical model and d-dimer". Ann Intern Med. 135 (2): 98–107. PMID 11453709.
- ↑ Stein PD, Woodard PK, Weg JG, Wakefield TW, Tapson VF, Sostman HD, Sos TA, Quinn DA, Leeper KV, Hull RD, Hales CA, Gottschalk A, Goodman LR, Fowler SE, Buckley JD (2007). "Diagnostic pathways in acute pulmonary embolism: recommendations of the PIOPED II Investigators". Radiology. 242 (1): 15–21. doi:10.1148/radiol.2421060971. PMID 17185658.
- ↑ 11.0 11.1 11.2 11.3 Sanson BJ, Lijmer JG, Mac Gillavry MR, Turkstra F, Prins MH, Büller HR (2000). "Comparison of a clinical probability estimate and two clinical models in patients with suspected pulmonary embolism. ANTELOPE-Study Group". Thromb. Haemost. 83 (2): 199–203. PMID 10739372.
- ↑ Geersing, G.-J. (2012-10-04). "Safe exclusion of pulmonary embolism using the Wells rule and qualitative D-dimer testing in primary care: prospective cohort study". BMJ. 345 (oct04 2): e6564–e6564. doi:10.1136/bmj.e6564. ISSN 1756-1833. Retrieved 2012-10-05. Unknown parameter
|coauthors=ignored (help) - ↑
- ↑
- ↑
- ↑ 16.0 16.1 16.2 Wicki J, Perneger TV, Junod AF, Bounameaux H, Perrier A (2001). "Assessing clinical probability of pulmonary embolism in the emergency ward: a simple score". Arch. Intern. Med. 161 (1): 92–7. PMID 11146703. Retrieved 2012-04-26. Unknown parameter
|month=ignored (help) - ↑ Iles S, Hodges AM, Darley JR, Frampton C, Epton M, Beckert LE, Town GI (2003). "Clinical experience and pre-test probability scores in the diagnosis of pulmonary embolism". QJM. 96 (3): 211–5. PMID 12615985. Retrieved 2012-04-26. Unknown parameter
|month=ignored (help) - ↑ 18.0 18.1 Klok FA, Mos IC, Nijkeuter M, Righini M, Perrier A, Le Gal G, Huisman MV (2008). "Simplification of the revised Geneva score for assessing clinical probability of pulmonary embolism". Arch. Intern. Med. 168 (19): 2131–6. doi:10.1001/archinte.168.19.2131. PMID 18955643. Retrieved 2012-04-26. Unknown parameter
|month=ignored (help) - ↑ 19.0 19.1 Le Gal G, Righini M, Roy PM, Sanchez O, Aujesky D, Bounameaux H, Perrier A (2006). "Prediction of pulmonary embolism in the emergency department: the revised Geneva score". Ann. Intern. Med. 144 (3): 165–71. PMID 16461960. Unknown parameter
|month=ignored (help);|access-date=requires|url=(help) - ↑ Righini M, Le Gal G, Aujesky D, Roy PM, Sanchez O, Verschuren F, Rutschmann O, Nonent M, Cornuz J, Thys F, Le Manach CP, Revel MP, Poletti PA, Meyer G, Mottier D, Perneger T, Bounameaux H, Perrier A (2008). "Diagnosis of pulmonary embolism by multidetector CT alone or combined with venous ultrasonography of the leg: a randomised non-inferiority trial". Lancet. 371 (9621): 1343–52. doi:10.1016/S0140-6736(08)60594-2. PMID 18424324. Retrieved 2012-04-26. Unknown parameter
|month=ignored (help) - ↑ 21.0 21.1 Wolf SJ, McCubbin TR, Nordenholz KE, Naviaux NW, Haukoos JS (2008). "Assessment of the pulmonary embolism rule-out criteria rule for evaluation of suspected pulmonary embolism in the emergency department". The American Journal of Emergency Medicine. 26 (2): 181–5. doi:10.1016/j.ajem.2007.04.026. PMID 18272098. Retrieved 2012-04-30. Unknown parameter
|month=ignored (help) - ↑ Kline JA, Courtney DM, Kabrhel C, Moore CL, Smithline HA, Plewa MC, Richman PB, O'Neil BJ, Nordenholz K (2008). "Prospective multicenter evaluation of the pulmonary embolism rule-out criteria". J. Thromb. Haemost. 6 (5): 772–80. doi:10.1111/j.1538-7836.2008.02944.x. PMID 18318689. Retrieved 2012-04-26. Unknown parameter
|month=ignored (help) - ↑ Hugli O, Righini M, Le Gal G, Roy PM, Sanchez O, Verschuren F, Meyer G, Bounameaux H, Aujesky D (2011). "The pulmonary embolism rule-out criteria (PERC) rule does not safely exclude pulmonary embolism". J. Thromb.Haemost. 9 (2): 300–4. doi:10.1111/j.1538-7836.2010.04147.x. PMID 21091866. Retrieved 2011-12-19. Unknown parameter
|month=ignored (help) - ↑ 24.0 24.1 Chagnon I, Bounameaux H, Aujesky D, Roy PM, Gourdier AL, Cornuz J, Perneger T, Perrier A (2002). "Comparison of two clinical prediction rules and implicit assessment among patients with suspected pulmonary embolism". The American Journal of Medicine. 113 (4): 269–75. PMID 12361811. Retrieved 2012-04-30. Unknown parameter
|month=ignored (help) - ↑ Stein PD, Woodard PK, Weg JG, Wakefield TW, Tapson VF, Sostman HD, Sos TA, Quinn DA, Leeper KV, Hull RD, Hales CA, Gottschalk A, Goodman LR, Fowler SE, Buckley JD (2006). "Diagnostic pathways in acute pulmonary embolism: recommendations of the PIOPED II investigators". The American Journal of Medicine. 119 (12): 1048–55. doi:10.1016/j.amjmed.2006.05.060. PMID 17145249. Retrieved 2012-04-30. Unknown parameter
|month=ignored (help) - ↑ 26.0 26.1 Torbicki A, Perrier A, Konstantinides S, Agnelli G, Galiè N, Pruszczyk P, Bengel F, Brady AJ, Ferreira D, Janssens U, Klepetko W, Mayer E, Remy-Jardin M, Bassand JP (2008). "Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC)". Eur. Heart J. 29 (18): 2276–315. doi:10.1093/eurheartj/ehn310. PMID 18757870. Retrieved 2011-12-07. Unknown parameter
|month=ignored (help)