Management of Pulmonary Embolism

- See: - deep venous thrombosis / respiratory failure

- Discussion:
    - time range of diagnosis of PE following discharge:  14-68 days (JR Lieberman et al);
          - ref: Early pulmonary embolism after injury: A different clinical entity?
    - in the report by Lawton RL and Morrey BF (1999), the authors advise that patients who demonstrate clinical signs of a PE should have the diagnosis
                  confirmed before starting empiric IV heparin;
                  - they noted at 47% complication rate in their patients (versus 20% in patients that did not receive heparin);
                  - they found no benefit to starting IV heparin prior to confirmation of the diagnosis;
    - consider hypercoagulable conditions:
    - pulmonary embolism from specific conditions:
           - PE arising from trauma, pelvic fractures, and extremity fractures:
                 - risk of pulmonary embolism following acetabular fractures is about 4-7%;
           - PE in hip frx and surgery:
           - PE following THR:
           - PE following TKR:
           - PE arising from trauma and fractures:
           - references:
                 - Correlation of Thrombophilia and Hypofibrinolysis with Pulmonary Embolism Following Total Hip Arthroplasty: an analysis of genetic factors.


- Clinical Findings:
    - hypoxia: 63 % of patients will have a pulse ox level less than 90%;
    - arterial blood gas
           - acute respiratory alkalosis;
           - pO2 < 80mm on Rm Air;
           - elevated (A-a)O2 gradient;
    - troponin may be elevated;
    - EKG changes:
    - references:
          - Continuous pulse oximetry and the diagnosis of pulmonary embolism in critically ill trauma patients.
          - Clinical presentation of pulmonary embolus after total joint arthroplasty: do size and location of embolus matter?

- Diagnostic Studies:
        - CT scan:
                 - ref: A Pilot Study of Computed Tomography–Detected Asymptomatic Pulmonary Filling Defects After Hip and Knee Arthroplasties 
        - VQ scan: reasonable if the patient can cooperate with the ventilation part of the test (ie not too SOB or disoriented);
                 - ref: Clinical validity of a normal perfusion lung scan in patients with suspected pulmonary embolism.


- Management:
    - anticoagulation:
           - used if no contraindications exist;
           - treatment modalities for DVT: 
                 - lovenox: (lovenox dosing calculator)
                 - heparin 
                      - in the report by Lawton RL and Morrey BF (1999), the authors advise that patients who demonstrate clinical signs of a PE should have dx
                                confirmed before starting empiric IV heparin;
                                - they noted at 47% complication rate in their patients (versus 20% in patients that did not receive heparin);
                                - they found no benefit to starting IV heparin prior to confirmation of the diagnosis;
                        - IV Heparain is started to keep PTT > 2.0 times normal.
                        - need to be aware of heparin induced thrombocytopenia.
                        - references: - The use of heparin in patients in whom a pulmonary embolism is suspected after total hip arthroplasty.

                 - warfarin
                       - patient must be anticoaguated with Heparin before Coumadin is started in order to avoid skin necrosis
                       - begin heparin or lovenox: plan to continue heparin for 7-10 days;
                       - plan to add warfarin at day 3;
                       - d/c heparin after about 1 week;
                       - plan to continue warfarin for 2-6 months;
                  - refs: 
                       - Optimum duration of anticoagulation for deep-vein thrombosis and pulmonary embolism. Research Committee of the British Thoracic Society.
                 - Apixaban: (oral factor Xa inhibitor) may be given 2.5 mg or 5 mg PO qd.
                       - Apixaban for Extended Treatment of Venous Thromboembolism

    - vena cava filter:
           - indicated if there are contraindications to anticoagulation:
           - in multi-trauma patients consider prophylactic placement of a vena cava filter;
           - decrease in incidence of pulmonary embolism can be expected;
           - filters should remove 98% of emboli;
           - filters should prevent fatal emboli in about 2-4% of patients undergoing major acetabular fixation (as compared to  other forms of DVT prophylaxis);
           - long term patency rate of IVC is about 94% at 1-2 years;
           - sudden severe leg edema following filter insertion may indicate the occurance of a large embolus;
           - criteria for filter placement (2/5 criteria must be met);
                  - age greater than 55 yrs;
                  - ISS greater than 16;
                  - complex pelvic fracture;
                  - long bone and pelvic fracture;
                  - fracture (pelvic / lower extremity) requiring prolonged bed rest;
           - references:
                  - Prophylactic vena cava filter insertion in severely injured trauma patients: indications and preliminary results.
                  - Prophylactic Vena Cava Filter Insertion in Selected High-Risk Orthopaedic Trauma Patients
                  - Greenfield filter prophylaxis of pulmonary embolism in patients undergoing surgery for acetabular fracture
    - thrombolytic therapy: (urokinase, streptokinase)
           - thrombolysis is indicated in the case of patients with pulmonary embolism who have arterial hypotension or are in shock;
           - need for thrombolytic treatments depends on presence and severity of hemodynamic instability due to right ventricular failure;
           - selected patients with evidence of right ventricular dysfunction and a low risk of bleeding may benefit from early thrombolysis;
           - complications: 13% cumulative rate of major bleeding and a 1.8% rate of intracranial or fatal hemorrhage
           - references:
                   - Recent advances in the diagnosis and lytic therapy of pulmonary embolism.
                   - Thrombolytic therapy for postoperative pulmonary embolism.



- References:

Clinical Cardiology: Diagnosis, Treatment, and Prevention of Pulmonary Embolism: Report of the WHO/International Society and Federation of Cardiology Task Force.

Original Contributions: A Prospective Investigation of Pulmonary Embolism in Women and Men.

The incidence of fatal pulmonary embolism after knee replacement with no prophylactic anticoagulation.

The clinical course of pulmonary embolism.

Reduction in fatal pulmonary embolism and venous thrombosis by perioperative administration of subcutaneous heparin. Overview of results of randomized trials in general, orthopedic, and urologic surgery

Thromboembolism following multiple trauma.

Autopsy-verified major pulmonary embolism after hip fracture.

Brief Report: Frequent Asymptomatic Pulmonary Embolism in Patients With Deep Venous Thrombosis.

The efficacy of sequential compression devices in multiple trauma patients with severe head injury.

Risk of pulmonary emboli in patients with pelvic fractures.

Symptomatic pulmonary embolism after outpatient arthroscopic procedures of the knee: the incidence and risk factors in 418,323 arthroscopies.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, February 7, 2014 3:56 pm