Pulmonary embolism laboratory findings: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
|||
| Line 18: | Line 18: | ||
== Electrolyte and Biomarker Studies == | == Electrolyte and Biomarker Studies == | ||
===='''[[Arterial blood gas]] '''(ABG)==== | ===='''[[Arterial blood gas]] '''(ABG)==== | ||
* A study had shown, that in patients without prior cardiopulmonary disease, 98% of patients with PE had either an increased Alveolar-arterial oxygen difference (AaDO2) or [[hypocapnia]]<ref name="pmid2491801">{{cite journal| author=Cvitanic O, Marino PL| title=Improved use of arterial blood gas analysis in suspected pulmonary embolism. | journal=Chest | year= 1989 | volume= 95 | issue= 1 | pages= 48-51 | pmid=2491801 | doi= |pmc= | url= }} </ref> | * A study had shown, that in patients without prior cardiopulmonary disease, 98% of patients with PE had either an increased Alveolar-arterial oxygen difference (AaDO2) or [[hypocapnia]].<ref name="pmid2491801">{{cite journal| author=Cvitanic O, Marino PL| title=Improved use of arterial blood gas analysis in suspected pulmonary embolism. | journal=Chest | year= 1989 | volume= 95 | issue= 1 | pages= 48-51 | pmid=2491801 | doi= |pmc= | url= }} </ref> | ||
**In a patient without cardiopulmonary disease, having a normal AaDO2 and a normal PaCO2, the probability of PE is very unlikely (i.e. 2%). | **In a patient without cardiopulmonary disease, having a normal AaDO2 and a normal PaCO2, the probability of PE is very unlikely (i.e. 2%). | ||
* Other studies have found ABG lacking enough sensitivity, specificity, positive or negative predictive value to either diagnose PE or prevent further testing in patients thought to have PE<ref name="pmid17145249">{{cite journal| author=Stein PD, Woodard PK, Weg JG, Wakefield TW, Tapson VF, Sostman HD et al.| title=Diagnostic pathways in acute pulmonary embolism: recommendations of the PIOPED II investigators. | journal=Am J Med | year= 2006 | volume= 119 | issue= 12 | pages= 1048-55 | pmid=17145249 | doi=10.1016/j.amjmed.2006.05.060 | pmc= |url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17145249 }}</ref> | * Other studies have found ABG lacking enough sensitivity, specificity, positive or negative predictive value to either diagnose PE or prevent further testing in patients thought to have PE.<ref name="pmid17145249">{{cite journal| author=Stein PD, Woodard PK, Weg JG, Wakefield TW, Tapson VF, Sostman HD et al.| title=Diagnostic pathways in acute pulmonary embolism: recommendations of the PIOPED II investigators. | journal=Am J Med | year= 2006 | volume= 119 | issue= 12 | pages= 1048-55 | pmid=17145249 | doi=10.1016/j.amjmed.2006.05.060 | pmc= |url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17145249 }}</ref> | ||
===='''[[D-dimer|D-dimers]]'''==== | ===='''[[D-dimer|D-dimers]]'''==== | ||
| Line 34: | Line 34: | ||
# Pregnancy | # Pregnancy | ||
# After surgery | # After surgery | ||
# Hospitalized patient<ref name="pmid19712840">{{cite journal| author=Bruinstroop E, van de Ree MA, Huisman MV| title=The use of D-dimer in specific clinical conditions: a narrative review. | journal=Eur J Intern Med | year= 2009 | volume= 20 | issue= 5 | pages= 441-6 | pmid=19712840 | doi=10.1016/j.ejim.2008.12.004 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19712840 }} </ref> | # Hospitalized patient.<ref name="pmid19712840">{{cite journal| author=Bruinstroop E, van de Ree MA, Huisman MV| title=The use of D-dimer in specific clinical conditions: a narrative review. | journal=Eur J Intern Med | year= 2009 | volume= 20 | issue= 5 | pages= 441-6 | pmid=19712840 | doi=10.1016/j.ejim.2008.12.004 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19712840 }} </ref> Thus, most hospitalized patients should not undergo D-dimer testing if PE is suspected.<ref name="pmid20592294">{{cite journal| author=Agnelli G, Becattini C| title=Acute pulmonary embolism. | journal=N Engl J Med | year= 2010 | volume= 363 | issue= 3 | pages= 266-74 | pmid=20592294 | doi=10.1056/NEJMra0907731 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20592294 }} </ref> | ||
Patients who are '''hemodynamically stable''', but have a high clinical probability or those having a high d-dimer level should undergo [[Computed tomography#Multislice CT|multidetector CT]]<ref name="pmid16403929">{{cite journal| author=van Belle A, Büller HR, Huisman MV, Huisman PM, Kaasjager K, Kamphuisen PW et al.| title=Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography. | journal=JAMA | year= 2006 | volume= 295 | issue= 2 | pages= 172-9 | pmid=16403929 | doi=10.1001/jama.295.2.172 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16403929 }} </ref> | Patients who are '''hemodynamically stable''', but have a high clinical probability or those having a high d-dimer level should undergo [[Computed tomography#Multislice CT|multidetector CT]].<ref name="pmid16403929">{{cite journal| author=van Belle A, Büller HR, Huisman MV, Huisman PM, Kaasjager K, Kamphuisen PW et al.| title=Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography. | journal=JAMA | year= 2006 | volume= 295 | issue= 2 | pages= 172-9 | pmid=16403929 | doi=10.1001/jama.295.2.172 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16403929 }} </ref> The following table depicts the incidences of thromboembolic events in hemodynamicaly stable patients. | ||
{| border="1" | {| border="1" | ||
|+ | |+ | ||
| Line 51: | Line 51: | ||
|} | |} | ||
In '''low-to-moderate''' suspicion of PE, a normal [[D-dimer]] level (shown in a [[blood test]]) is enough to exclude the possibility of thrombotic PE<ref name="pmid8165626">{{cite journal |author=Bounameaux H, de Moerloose P, Perrier A, Reber G|title=Plasma measurement of D-dimer as diagnostic aid in suspected venous thromboembolism: an overview |journal=Thromb. Haemost.|volume=71 |issue=1 |pages=1-6 |year=1994 |pmid=8165626 |doi=}}</ref> | In '''low-to-moderate''' suspicion of PE, a normal [[D-dimer]] level (shown in a [[blood test]]) is enough to exclude the possibility of thrombotic PE.<ref name="pmid8165626">{{cite journal |author=Bounameaux H, de Moerloose P, Perrier A, Reber G|title=Plasma measurement of D-dimer as diagnostic aid in suspected venous thromboembolism: an overview |journal=Thromb. Haemost.|volume=71 |issue=1 |pages=1-6 |year=1994 |pmid=8165626 |doi=}}</ref> In patients with '''High''' clinical probability, the use of the d-dimer assay is of limited value.<ref name="pmid19620439">{{cite journal| author=Gupta RT, Kakarla RK, Kirshenbaum KJ, Tapson VF| title=D-dimers and efficacy of clinical risk estimation algorithms: sensitivity in evaluation of acute pulmonary embolism. |journal=AJR Am J Roentgenol | year= 2009 | volume= 193 | issue= 2 | pages= 425-30 | pmid=19620439 |doi=10.2214/AJR.08.2186 | pmc= |url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19620439 }} </ref> | ||
'''The following flowchart summarize the role of D-dimer''': | '''The following flowchart summarize the role of D-dimer''': | ||
| Line 77: | Line 77: | ||
===='''[[Troponin]]'''==== | ===='''[[Troponin]]'''==== | ||
Serum troponin I and troponin T are elevated in approximately thirty to fifty percent of the PE patients<ref name="pmid12904706">{{cite journal| author=Horlander KT, Leeper KV| title=Troponin levels as a guide to treatment of pulmonary embolism. | journal=Curr Opin Pulm Med | year= 2003 | volume= 9 | issue= 5 | pages= 374-7 | pmid=12904706 | doi= | pmc= | url= }} </ref><ref name="pmid12208803">{{cite journal| author=Konstantinides S, Geibel A, Olschewski M, Kasper W, Hruska N, Jäckle S et al.| title=Importance of cardiac troponins I and T in risk stratification of patients with acute pulmonary embolism. | journal=Circulation | year= 2002 | volume= 106 | issue= 10 | pages= 1263-8 | pmid=12208803 | doi= | pmc= | url= }} </ref> | Serum troponin I and troponin T are elevated in approximately thirty to fifty percent of the PE patients.<ref name="pmid12904706">{{cite journal| author=Horlander KT, Leeper KV| title=Troponin levels as a guide to treatment of pulmonary embolism. | journal=Curr Opin Pulm Med | year= 2003 | volume= 9 | issue= 5 | pages= 374-7 | pmid=12904706 | doi= | pmc= | url= }} </ref><ref name="pmid12208803">{{cite journal| author=Konstantinides S, Geibel A, Olschewski M, Kasper W, Hruska N, Jäckle S et al.| title=Importance of cardiac troponins I and T in risk stratification of patients with acute pulmonary embolism. | journal=Circulation | year= 2002 | volume= 106 | issue= 10 | pages= 1263-8 | pmid=12208803 | doi= | pmc= | url= }} </ref> The suspected mechanism is due to acute right heart overload.<ref name="pmid11079669">{{cite journal| author=Meyer T, Binder L, Hruska N, Luthe H, Buchwald AB| title=Cardiac troponin I elevation in acute pulmonary embolism is associated with right ventricular dysfunction. | journal=J Am Coll Cardiol | year= 2000 | volume= 36 | issue= 5 | pages= 1632-6 | pmid=11079669 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11079669 }} </ref> Troponin elevation is more prolonged in acute MI rather in PE and usually resolve within 40 hours after a PE event.<ref name="pmid11901075">{{cite journal| author=Müller-Bardorff M, Weidtmann B, Giannitsis E, Kurowski V, Katus HA| title=Release kinetics of cardiac troponin T in survivors of confirmed severe pulmonary embolism. | journal=Clin Chem | year= 2002 | volume= 48 | issue= 4 | pages= 673-5 | pmid=11901075 | doi= | pmc= | url= }} </ref> Thus troponins are not useful for diagnosis, but there role in prognostic assessment has been proved in a meta-analysis.<ref name="pmid18094010">{{cite journal| author=Jiménez D, Díaz G, Molina J, Martí D, Del Rey J, García-Rull S et al.| title=Troponin I and risk stratification of patients with acute nonmassive pulmonary embolism. | journal=Eur Respir J | year= 2008 | volume= 31 | issue= 4 | pages= 847-53 | pmid=18094010 | doi=10.1183/09031936.00113307 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18094010 }} </ref> | ||
==References== | ==References== | ||
Revision as of 04:13, 21 January 2012
|
Pulmonary Embolism Microchapters |
|
Diagnosis |
|---|
|
Pulmonary Embolism Assessment of Probability of Subsequent VTE and Risk Scores |
|
Treatment |
|
Follow-Up |
|
Special Scenario |
|
Trials |
|
Case Studies |
|
Pulmonary embolism laboratory findings On the Web |
|
Directions to Hospitals Treating Pulmonary embolism laboratory findings |
|
Risk calculators and risk factors for Pulmonary embolism laboratory findings |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editors-in-Chief: Ujjwal Rastogi, MBBS [2]
Overview
Arterial blood gas (ABG) measurements and pulse oximetry have a limited role in diagnosing PE. Also, routine laboratory testing are nonspecific. They include:
- Leukocytosis
- Raised erythrocyte sedimentation rate (ESR)
- Raised serum LDH or AST (SGOT) with a normal serum bilirubin.
Blood tests
When PE is suspected, in order to exclude secondary causes of PE, a number of blood tests are done. These include:
- Full blood count
- Clotting status (prothrombin time (PT), APTT, thrombin time (TT))
- Some screening tests (erythrocyte sedimentation rate, renal function, liver enzymes, electrolytes).
If results are abnormal, further investigations might be warranted.
Electrolyte and Biomarker Studies
Arterial blood gas (ABG)
- A study had shown, that in patients without prior cardiopulmonary disease, 98% of patients with PE had either an increased Alveolar-arterial oxygen difference (AaDO2) or hypocapnia.[1]
- In a patient without cardiopulmonary disease, having a normal AaDO2 and a normal PaCO2, the probability of PE is very unlikely (i.e. 2%).
- Other studies have found ABG lacking enough sensitivity, specificity, positive or negative predictive value to either diagnose PE or prevent further testing in patients thought to have PE.[2]
D-dimers
This is formed by the degradation of fibrin clot. Almost all patients with PE have some endogenous fibrinolysis, and therefore have elevated levels of D-dimer.
- The negative predictive value (when done by ELISA) is 91% – 94% .
- Many other diseases are associated with a mild degree of fibrinolysis, and hence an elevated D-dimer is not specific for pulmonary embolism. Disease with elevated levels of D-dimer are:
D-Dimer levels are elevated in other medical conditions such as:
- Pregnancy
- After surgery
- Hospitalized patient.[3] Thus, most hospitalized patients should not undergo D-dimer testing if PE is suspected.[4]
Patients who are hemodynamically stable, but have a high clinical probability or those having a high d-dimer level should undergo multidetector CT.[5] The following table depicts the incidences of thromboembolic events in hemodynamicaly stable patients.
| Condition | Incidence of thromboembolic event (%) |
|---|---|
| Patients not receiving anticoagulation and with negative CT findings. | 1.5%[6][5] |
| Patients with High d-dimer level | 1.5% |
| Patients with Normal d-dimer level | 0.5%[6] |
In low-to-moderate suspicion of PE, a normal D-dimer level (shown in a blood test) is enough to exclude the possibility of thrombotic PE.[7] In patients with High clinical probability, the use of the d-dimer assay is of limited value.[8]
The following flowchart summarize the role of D-dimer:
| Patients with suspection of Pulmonary embolism | |||||||||||||||||||||||
| Clinically Low or Moderate | Clinically High | ||||||||||||||||||||||
| D-Dimer Positive | |||||||||||||||||||||||
| D-Dimer Negative | |||||||||||||||||||||||
| No treatment | Further Tests | Further Tests | |||||||||||||||||||||
Brain natriuretic peptide (BNP)
In a case-control study of 2213 hemodynamically stable patients with suspected acute PE, BNP was found to have 60% sensitivity and 62% specificity.[9]
BNP levels are typically higher in PE patients as compared to patients without PE; however, certain features limit its usefulness as a diagnostic test:
- Many patients with PE do not have elevated BNP levels.
- There are many alternative causes of an elevated BNP level (proving it to be nonspecific).[10]
In hemodynamically stable patients, normal level of BNP and pro-BNP have 100% negative predictive value (NPV) for an adverse outcome.[4] High level of BNP distinguish patients with pulmonary embolism at higher risk of complicated in-hospital duration and death, when compared with those with low BNP levels. However an isolated increase in BNP or NT-pro-BNP level, do not justify more invasive treatment regimens.[11]
Troponin
Serum troponin I and troponin T are elevated in approximately thirty to fifty percent of the PE patients.[12][13] The suspected mechanism is due to acute right heart overload.[14] Troponin elevation is more prolonged in acute MI rather in PE and usually resolve within 40 hours after a PE event.[15] Thus troponins are not useful for diagnosis, but there role in prognostic assessment has been proved in a meta-analysis.[16]
References
- ↑ Cvitanic O, Marino PL (1989). "Improved use of arterial blood gas analysis in suspected pulmonary embolism". Chest. 95 (1): 48–51. PMID 2491801.
- ↑ Stein PD, Woodard PK, Weg JG, Wakefield TW, Tapson VF, Sostman HD; et al. (2006). "Diagnostic pathways in acute pulmonary embolism: recommendations of the PIOPED II investigators". Am J Med. 119 (12): 1048–55. doi:10.1016/j.amjmed.2006.05.060. PMID 17145249.
- ↑ Bruinstroop E, van de Ree MA, Huisman MV (2009). "The use of D-dimer in specific clinical conditions: a narrative review". Eur J Intern Med. 20 (5): 441–6. doi:10.1016/j.ejim.2008.12.004. PMID 19712840.
- ↑ 4.0 4.1 Agnelli G, Becattini C (2010). "Acute pulmonary embolism". N Engl J Med. 363 (3): 266–74. doi:10.1056/NEJMra0907731. PMID 20592294.
- ↑ 5.0 5.1 van Belle A, Büller HR, Huisman MV, Huisman PM, Kaasjager K, Kamphuisen PW; et al. (2006). "Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography". JAMA. 295 (2): 172–9. doi:10.1001/jama.295.2.172. PMID 16403929.
- ↑ 6.0 6.1 Perrier A, Roy PM, Sanchez O, Le Gal G, Meyer G, Gourdier AL; et al. (2005). "Multidetector-row computed tomography in suspected pulmonary embolism". N Engl J Med. 352 (17): 1760–8. doi:10.1056/NEJMoa042905. PMID 15858185. in: J Fam Pract. 2005 Aug;54(8):653, 657
- ↑ Bounameaux H, de Moerloose P, Perrier A, Reber G (1994). "Plasma measurement of D-dimer as diagnostic aid in suspected venous thromboembolism: an overview". Thromb. Haemost. 71 (1): 1–6. PMID 8165626.
- ↑ Gupta RT, Kakarla RK, Kirshenbaum KJ, Tapson VF (2009). "D-dimers and efficacy of clinical risk estimation algorithms: sensitivity in evaluation of acute pulmonary embolism". AJR Am J Roentgenol. 193 (2): 425–30. doi:10.2214/AJR.08.2186. PMID 19620439.
- ↑ Söhne M, Ten Wolde M, Boomsma F, Reitsma JB, Douketis JD, Büller HR (2006). "Brain natriuretic peptide in hemodynamically stable acute pulmonary embolism". J Thromb Haemost. 4 (3): 552–6. doi:10.1111/j.1538-7836.2005.01752.x. PMID 16405522.
- ↑ Kiely DG, Kennedy NS, Pirzada O, Batchelor SA, Struthers AD, Lipworth BJ (2005). "Elevated levels of natriuretic peptides in patients with pulmonary thromboembolism". Respir Med. 99 (10): 1286–91. doi:10.1016/j.rmed.2005.02.029. PMID 16099151.
- ↑ Klok FA, Mos IC, Huisman MV (2008). "Brain-type natriuretic peptide levels in the prediction of adverse outcome in patients with pulmonary embolism: a systematic review and meta-analysis". Am J Respir Crit Care Med. 178 (4): 425–30. doi:10.1164/rccm.200803-459OC. PMID 18556626.
- ↑ Horlander KT, Leeper KV (2003). "Troponin levels as a guide to treatment of pulmonary embolism". Curr Opin Pulm Med. 9 (5): 374–7. PMID 12904706.
- ↑ Konstantinides S, Geibel A, Olschewski M, Kasper W, Hruska N, Jäckle S; et al. (2002). "Importance of cardiac troponins I and T in risk stratification of patients with acute pulmonary embolism". Circulation. 106 (10): 1263–8. PMID 12208803.
- ↑ Meyer T, Binder L, Hruska N, Luthe H, Buchwald AB (2000). "Cardiac troponin I elevation in acute pulmonary embolism is associated with right ventricular dysfunction". J Am Coll Cardiol. 36 (5): 1632–6. PMID 11079669.
- ↑ Müller-Bardorff M, Weidtmann B, Giannitsis E, Kurowski V, Katus HA (2002). "Release kinetics of cardiac troponin T in survivors of confirmed severe pulmonary embolism". Clin Chem. 48 (4): 673–5. PMID 11901075.
- ↑ Jiménez D, Díaz G, Molina J, Martí D, Del Rey J, García-Rull S; et al. (2008). "Troponin I and risk stratification of patients with acute nonmassive pulmonary embolism". Eur Respir J. 31 (4): 847–53. doi:10.1183/09031936.00113307. PMID 18094010.