Morning Report: PE Diagnosis Algorithm

Hey Thanks to Dr. Grock for today’s Morning Report!

 

Case 1: 75 year old female with pmhx DVT no longer on Coumadin, recent radical mastectomy currently on chemo/rad for breast cancer presents after long flight with pleuritic chest pain and shortness of breath. She is tachycardic, tachypnic, and hypoxic.

Diagnosis? PE

How to Diagnose? CTPA

 

Case 2: 27 year old female, no pmhx, on OCPs, Mom currently with DVT, presents with chest pain, mild decreased ET and mild SOB. HR 101, RR 18, 120/70, 98% on RA.

Diagnosis? More difficult

Concerned for PE? Maybe

How to evaluate patient for PE?

 

Step 1: Gestalt – do you think this person needs a PE workup? If no, done. If yes, see Step 2

 

Step 2: PERC [2]- If all 8 negative, clinically ruled out PE. If 1 or more positive, see Step 3

1. age < 50
2. HR < 100
3. SpO2 > 95%
4. No unilateral leg swelling
5. No hemoptysis
6. No recent trauma or surgery
7. No prior DVT or PE
8. No hormone use

 

 

Step 3: D-Dimer? I use Wells Criteria [3] with score < 4 low risk and, therefore, appropriate for D-Dimer. If D-Dimer negative, ruled out PE. If D-Dimer positive, do CTPA. For scores >4. Jump to CTPA. If wells >4 and D-Dimer negative? Means little. Incidence of PE too high in this group to effectively rule out with D-Dimer. Do the CTPA.

 

Wells Criteria

1. Clinical signs and symptoms of DVT? (+3)
2. Pulmonary embolism is most likely diagnosis (+3)
3. HR > 100 (+1.5)
4. Immobilization >3 days or surgery in previous 4 weeks (+1.5)
5. Previous PE or DVT (+1.5)
6. Hemoptysis (+1)
7. Malignancy with treatment in past 6 months, or palliative (+1)

 

Score <4 qualifies using D dimer to rule out PE [JAMA 295 (2): 172-9]

 

Special note: Remember D-Dimer has high sensitivity, low specificity.

 

 

Interestingly D-Dimer increases with age

Study 1: ADJUST-PE [4]

-Prospective, in Europe

– 3324 patients (clinical suspicion of PE without exclusion criteria) with 331 having D-Dimer > 500, but < age-adjusted cutoff of age x 10 who completed follow-up and 810 with D-Dimer <500 who completed follow-up

– All assessed with RGS or Wells Score

– All patients followed-up by phone call at 3 months

– Presumed false negative rate for ADJUSTED D-Dimer = 1/331, 0.3% [95% CI, 0.1%-1.7%). For conventional D-Dimer = 1/810, 0.1%[95%CI, 0.0%-0.7%]).

– In the pos D-Dimer and neg CTPA group, 0.5% (95% CI 0.2%-1%) had suspected or proven VTE in the next 90 days.

 

 

Study 2 [5]

-Retrospective

– 3500 with CTPA for PE =>923 over age 50 with CTPA, D-Dimer, and Revised Geneva Score<10

– Used age x 10 for upper limit of D-Dimer

– False neg = neg D-dimer, with +CTPA <90 days (in Utah in hospital system that ran half of all hospitals)

– If ADJUSTED D-Dimer 273 ruled out

– If conventional D-Dimer 104 ruled out

– Decrease imaging by 18% in >50

12.4% in 51-65

24.7% 66-74

24.9% >75

– ADJUSTED D-dimer Sens 97.6 (92.6-99.6), Spec 32.4 (29.3-35.6)

-Conventional D-dimer Sens 100 (96.5-100), Spec 12.4 (10.3-14.7)

-Negative LR 0.07 (95% CI 0.02-0.29)

– Neg conventional D-Dimer = 0% (95% CI 0-2.8%) PE in <90 days

– Of neg ADJUSTED D-Dimer and + CTPA

4 patients:2 had neg CTPA on initial encounter (RGS 4,3) – WHICH SHOULDN’T really count, 2 on initial CTPA (RGS 1,1)

LR 0.7% (95% CI 0.1-2.6%)

 

 

Another scoring system for funsies!

           The Revised Geneva Score [6]

Risk factors

1. Age > 65 y = 1 point
2. Previous DVT or PE = 3 points
3. Surgery (under general anesthesia) or fracture (of the lower limbs) within 1 mo = 2 points
4. Active malignant condition (solid or hematologic malignant condition, currently active or considered cured <1 yr) = 2 points

 

Symptoms

1. Unilateral lower-limb pain = 3 points
2. Hemoptysis = 2 points

 

 

Clinical signs

• Heart rate

75–94 beats/min = 3 points

>95 beats/min = 5 points

• Pain on lower-limb deep venous palpation and unilateral edema = 4 points

 

 

Clinical probability:

Low 0–3 (around 9% prevalence of PE)

Intermediate 4–10 (around 27% prevalence of PE)

High >11 (around 40% prevalence of PE)

 

 

References:

[1] Boka, K et al. Pulmonary Embolism Scoring Systems, emedicine. Feb 2014. Retrieved from http://emedicine.medscape.com/article/1918940-overview#a1

[2] Kline JA et al. Prospective multicenter evaluation of the pulmonary embolism rule-out criteria. J Thromb Haemost. 2008 May;6(5):772-80. doi: 10.1111/j.1538-7836.2008.02944.x. Epub 2008 Mar 3.

[3] 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.

[4] Righini M^. et al. Age-adjusted D-dimer cutoff levels to rule out pulmonary embolism: the ADJUST-PE study. JAMA. 2014 Mar 19;311(11):1117-24. doi: 10.1001/jama.2014.2135.

[5] Woller et al. Assessment of the safety and efficiency of using an age-adjusted d-dimer threshold to exclude suspected pulmonary embolism. Chest. 2014 May 15. doi: 10.1378/chest.13-2386.

[6] Le Gal G Prediction of pulmonary embolism in the emergency department: the revised Geneva score. Ann Intern Med. 2006 Feb 7;144(3):165-71.