Molecular structure pattern

Venous Thromboembolism - Management Initial Assessment

Last updated: 22 September 2026

Clinical Presentation

DVT

The signs and symptoms suggestive of DVT include localized tenderness along the distribution of the deep venous system, swelling on a unilateral or an entire leg, swelling with a difference in calf or thigh circumference; calf swelling >3 cm compared to an asymptomatic leg (measured 10 cm below tibial tuberosity), pitting edema that is greater in the symptomatic leg, dilated collateral superficial veins (non-varicose), erythema, warmth, and superficial thrombophlebitis with a palpable cord over a superficial vein.   

Phlegmasia alba dolens (pale, white, or milk leg) is the presence of pallor in the edematous legs and is due to the interstitial tissue pressure exceeding the capillary perfusion pressure. Additionally, it is caused by the early compromise of arterial blood flow from extensive iliofemoral DVT. It is commonly seen in patients with thrombus in the major deep veins.

Phlegmasia cerulea dolens (blue leg) happens when deoxygenated hemoglobin in the stagnant veins causes a cyanotic hue in the leg. Advanced stages are seen in severe forms of iliocaval or iliofemoral DVT causing total outflow obstruction with rapid extension of thrombosis into all deep and superficial veins, including collaterals over a few hours leading to sudden severe ischemic pain, massive limb congestion, cyanosis, loss of function, tachycardia, and shock.  This may lead to venous gangrene. 

Pulmonary Embolism

The suspicion of pulmonary embolism is usually raised by the clinical symptoms. Clinical findings are non-specific and should not be the only criteria to diagnose pulmonary embolism. Dyspnea, pleuritic chest pain, syncope, and tachypnea (respiratory rate ≥20/minute) occur in most cases of pulmonary embolism.  

Dyspnea is the most frequent symptom, while tachypnea is its most frequent sign. Other signs and symptoms that may be present include tachycardia (heart rate >100 beats per minute [bpm]), cough and hemoptysis, fever, diaphoresis, non-pleuritic chest pain, apprehension, decreased breath sounds, rales, increasing pulmonic component of the second heart sound, wheezing, parasternal lift, hypotension, hypoxia, cyanosis, pleural friction rub, and raised jugular venous pressure. Pulmonary embolism should be suspected in cases of postoperative hypoxemia.  

Pleuritic chest pain with or without dyspnea is one of the most frequent presentations of pulmonary embolism. It may suggest a small embolism located distally near the pleura that also causes pleural irritation.  

Isolated dyspnea may occur suddenly or progressively (over several weeks). It is usually due to a more central pulmonary embolism (not affecting the pleura). It may be associated with substernal angina-like chest pain that probably represents RV ischemia. Worsening dyspnea may be the only symptom that indicates pulmonary embolism in patients with pre-existing HF or pulmonary disease.  

Syncope or shock is the hallmark sign of central pulmonary embolism and usually results in severe hemodynamic repercussions. The signs of hemodynamic compromise and reduced heart flow are also usually present (eg systemic arterial hypotension, oliguria, cold extremities, and/or clinical signs of acute right HF).  

Diagnosis or Diagnostic Criteria

Clinical findings are important in the diagnosis of DVT but are poor predictors of the presence or severity of thrombosis. Pretest probability is needed to guide the diagnostic process. 

WELLS SCORE OF CLINICAL PRETEST PROBABILITY FOR DVT
Clinical Features Points     Pretest              Total
 Probability          Points
Entire leg swollen 1.0 High risk≥3
Moderate risk1-2
Low risk≤0


If both legs are symptomatic, score the more severe side


Simplified version*:
DVT likely≥2
DVT unlikely<2
Calf swollen by >3 cm compared to the asymptomatic side (measured 10 cm below tibial tuberosity) 1.0
Localized tenderness along the deep venous system distribution 1.0
Pitting edema (greater in the symptomatic leg) 1.0
Dilated collateral superficial veins (non-varicose) 1.0
Immobilization for >3 days or major surgery within 12 weeks 1.0
Paralysis, paresis, recent plaster immobilization of lower extremity 1.0
Previously documented DVT 1.0
Active cancer (ongoing treatment within the last 6 months or current palliative therapy) 1.0
Alternative diagnosis as likely or greater than that of DVT -2.0
Reference: Institute for Clinical Systems Improvement. Health care guideline: venous thromboembolism diagnosis and treatment. 13th ed. Jan 2013.
*National Institute for Health and Care Excellence (NICE). Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. https://www.nice.org.uk. 26 Mar 2020.



Pretest Probability of Pulmonary Embolism

All patients with possible pulmonary embolism should have their clinical probability assessed and documented. Clinical probability may be estimated empirically or explicitly by a prediction rule. There are 2 frequently used pretest probabilities of pulmonary embolism which are the Geneva score (Europe) and Wells score (Canadian rule).  

Geneva Score  

Geneva score requires arterial blood gas measurement and a chest radiograph.

GENEVA CLINICAL PREDICTION RULE FOR PULMONARY EMBOLISM
Clinical Features Points Simplified Version     Pretest               Total
 Probability           Points
Simplified Version
Age >65 years 1 1 Based on likelihood of PE
Pulmonary embolism likely≥6
Pulmonary embolism less likely0-5


According to risk groups
High≥11
Intermediate4-10
Low0-3

≥3
0-2



≥5
2-4
0-1
Active cancer 2 1
Fracture or surgery within the past month 2 1
Heart rate
     75-94 bpm
     ≥95 bpm

3
5

1
2
Hemoptysis 2 1
Previous DVT or Pulmonary embolism 3 1
Unilateral edema and pain on lower-limb deep venous palpation 4 1
Unilateral pain in lower limb 3 1
References: 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS): The Task Force for the diagnosis and management of acute pulmonary embolism of the European Society of Cardiology (ESC). Eur Respir J. 31 Aug 2019.
Writing Committee Members; Creager MA, Barnes GD, Giri J, et al. 2026 AHA/ACC/ACCP/ACEP/CHEST/SCAI/SHM/SIR/SVM/SVN guideline for the evaluation and management of acute pulmonary embolism in adults: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2026 Mar 24;153(12):e977-e1051.
 

Wells Score

The Wells score requires that the patient has clinical features suggestive of pulmonary embolism (eg breathlessness, and/or tachypnea with or without pleuritic chest pain and/or hemoptysis), along with 2 other features, the absence of another reasonable clinical explanation and the presence of a major risk factor.

WELLS SCORE OF CLINICAL PRETEST PROBABILITY FOR PULMONARY EMBOLISM
Clinical Features Points Simplified Version*     Pretest               Total
 Probability           Points
Clinical signs and symptoms of DVT 3.0 1 Based on likelihood of PE
Pulmonary embolism likely>4
Pulmonary embolism less likely≤4


According to risk groups
High>6
Intermediate2-6
Low<2
 

Simplified version*:
Likely≥2
Unlikely<2
Alternative diagnosis is less likely than Pulmonary embolism 3.0 1
Heart rate ≥100 bpm 1.5 1
Immobilization for ≥3 days or surgery within the past 4 weeks 1.5 1
Previous DVT or pulmonary embolism 1.5 1
Hemoptysis 1.0 1
Malignancy (with treatment within the last 6 months or palliative) 1.0 1
Reference: Writing Committee Members; Creager MA, Barnes GD, Giri J, et al. 2026 AHA/ACC/ACCP/ACEP/CHEST/SCAI/SHM/SIR/SVM/SVN guideline for the evaluation and management of acute pulmonary embolism in adults: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2026 Mar 24;153(12):e977-e1051.
*2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS): The Task Force for the diagnosis and management of acute pulmonary embolism of the European Society of Cardiology (ESC). Eur Respir J. 31 Aug 2019.


Pulmonary Embolism Rule-Out Criteria (PERC)  

PERC is used to identify groups at very low risk of pulmonary embolism and to determine if additional investigations for pulmonary embolism are warranted.

If the patient has answered yes to any of the following questions, the patient is PERC positive: 

  • Is the patient >49 years old?
  • Is the patient’s heart rate >99 bpm? 
  • Is the patient’s pulse oximetry reading <95% while breathing room air?
  • Does the patient have hemoptysis?
  • Is the patient on exogenous Estrogen?
  • Does the patient have prior diagnosis of VTE?
  • Has the patient had surgery or trauma requiring hospitalization in the previous 4 weeks?
  • Does the patient have unilateral leg swelling at the calves?

In low-risk, pulmonary embolism can be ruled out without imaging tests or D-dimer if PERC is negative (ie score of 0).