A case of pulmonary embolism after orthopedic surgery

Valeria Clemente MD-Phd, Beniamino Susi MD

Department of Emergency Medicine of Polyclinic Tor Vergata Rome

Introduction

Pulmonary embolism is a life-threatening condition, with a high mortality rate. Recent studies show that 30-day mortality is 4%, but may increase to 13% after 90 days (1). The risk of developing a PE increases during and after surgery and it depends from the type of surgery and patient risk factors. Orthopedic procedures have the highest incidence of developing a PE with a 0.7% to 30% chance (2). Therefore an early prevention anticoagulant treatment should be initiated. We report the case of a PE occurred after a hip arthroplasty, although prophylactic therapy with enoxaparin.

Case Report

A 56- year old men arrived in the emergency department because of a brief episode of loss of consciousness. The patient was in good health. He reported that, two weeks before, had undergone a hip left arthroplasty and was in therapy with enoxaparin 6000 units once a day. He was hemodynamically stable and his oxygen saturation on room air was 98.5%, with lactate value of 2.3 mmol/L. The electrocardiogram showed rhythm rate of 76 beats per minute. No edema was noted, and peripheral pulses were normal. All other body systems were normal on examination. Laboratory exams were normal, except for increased D-dimer (4328 ng/mL, nv 0-500). The cerebral computed tomographic was normal. The pulmonary angiography showed a pulmonary embolism in some segmental branches of the right lower lung lobe. The lower extremity doppler revealed a deep left superficial femoral vein thrombosis. Therefore therapy with fondaparinux 7.5 mg once a day was started. Our patient, with low risk of complications, according to the pulmonary embolism severity index (3), was discharged in good condition after 10 days in therapy with fondaparinux 7.5 mg once a day, with advice to start therapy with new oral anticoagulants. After 60 days of therapy with dabigatran 150 mg once a day, a control pulmonary angiography revealed a complete resolution of embolism.

Discussion

Pulmonary embolism is a life-threatening condition that should be promptly recognized. Surgical patients are at increased risk of developing a PE, especially after orthopaedic hip and knee surgery, because of positioning during surgery and immobility, that contributes to an increase in venous stasis. Therefore the prophylactic therapy is essential. Despite standard thromboprophylaxis, symptomatic PE can occurred. A study on patients at large tertiary care hospital showed a PE in 14% of cases undergoing total knee replacement, higher than other previous studies, with a lower rate of PE using enoxaparin (4). Nowadays we have further to traditional therapy with enoxaparin twice a day and fondaparinux once a day, also new oral anticoagulants, such us dabigatran etexilate (220 mg or 150 mg once daily), an oral direct thrombin inhibitor, that are useful not only in the prevention, but also in the treatment of EP after orthopedic surgery, without significant differences and with a similar safety profile during treatment and follow up (5-7). Therefore dabigatran results not inferior to standard therapy with the benefit of a “single drug approach”, that in selected cases, can also guarantee a faster management at home.

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