Pulmonary Embolism: A Special Request

Aliases: pulmonary embolism, PE, venous thromboembolism

Because this is a special, themeless post, I decided to cut to the chase and talk about what I imagine people really want to know when they’ve been diagnosed with pulmonary embolism (PE): what will my life be like now? Within the medical community, quality of life (QoL) is defined as the “patients’ recorded impact of disease and treatment on his/her physical, psychological and social functioning and wellbeing”4. While the biological impact of PE is relatively concrete and can be conveniently assessed statistically, the social and psychological effects are subjective and consequently much harder to measure.

The clinical component of QoL is relatively straightforward and, in this case, fairly positive. The recurrence and mortality rates after diagnosis are low. PE-related mortality is less than 2% during the typical 3-6 month anticoagulant/thrombolytics treatment period following a PE, and remains fairly steady (rising to 2.7%) over the course of 3.1 years. The risk of recurrent PE is higher: around 6% during the first 6 months after diagnosis, and rising to a cumulative recurrence rate of between 29.1-34.5% (depending on the study) over the following 10 years. When recurrent PE occurs, it has an estimated case fatality rate of between 10-45%. However, this is very likely an overestimate, because autopsies are rarely conducted when recurrent PE is suspected as the cause of death. More likely than recurrence are related complications, such as residual perfusion defects, which affect 31.4% of PE patients within the first 12 months after their diagnosis2.

The social and psychological effect of PE, its impact on the patient’s perception of their wellbeing, is much more varied1, but there are some fairly consistent trends. While overall QoL for PE patients is lower than healthy control groups, it is significantly higher across the board than patients suffering from chronic cardiovascular diseases, specifically chronic obstructive pulmonary disease (COPD) and congestive heart failure. PE’s long-term impact is similar to other acute cardiovascular disorders; the QoL for PE patients is roughly equal to that of acute myocardial infarction (aka heart attack) patients. Finally, the best news: it gets better. The further from the diagnosis, the higher PE patients rated their QoL4.

pulmonary embolism
It’s all relative.

Cause: PE is caused by material, usually a blood clot, lodging in one or more pulmonary arteries, blocking blood flow to lung tissue. These clots almost always travel to the lungs from the legs and are often the result of deep vein thrombosis (DVT), a condition where a blood clot forms in a vein deep in the body. While anyone can develop DVT and PE, several factors increase the likelihood of their occurrence. Surgery, especially hip and knee replacements, are a leading cause, because they may introduce tissue debris into the bloodstream, and require immobility both during and after the procedure. Other risk factors include a family history of blood clots, heart disease, or certain cancers, as well as prolonged immobility (e.g. bed rest), being overweight, pregnancy and smoking. Unfortunately, one bad turn can beget another; once a person has had one embolism he or she has a greater risk of having another3.

Consequence: The most common symptoms of PE are a sudden shortness of breath that gets worse with exertion, chest pain, reminiscent of a heart attack, that may increase with coughing, breathing deeply, or bending over, and coughing that may produce bloody sputum. Other symptoms include leg pain or swelling, clammy or discolored skin, rapid or irregular heartbeat, dizziness, and excessive sweating. However, the symptoms of PE are highly variable, and depend on the size of the clots (there are almost always more than one), how much of the lung is affected, and the how healthy the person was before the PE3.

Cure: Treatment is critical for pulmonary embolism; approximately 1/3 of untreated patients will die. Because PE can be difficult to diagnose, physicians generally use multiple approaches, including blood tests for clotting factors, and a variety of body scans (e.g. x-rays, CT scans, or an MRI). Once it has been identified, PE is treated by either breaking down the blood clot with anticoagulants (blood thinners) and thrombolytics (clot dissolvers) or removing the clot surgically, or both. In extreme cases, PE is treated with an implanted vein filter that prevents blood clots from reaching the heart and lungs3.

References

1. Hogg, K, M Kimpton, M Carrier, D Coyle, M Forgie, & P Wells. (2013). Estimating quality of life in acute venous thrombosis. Journal of the American Medical Association Internal Medicine, 173(12).

2. Meyer, G, B Planquette, & O Sanchez. (2008). Long-term outcome of pulmonary embolism. Current Opinion in Hematology, 15:499-503.

3. Pulmonary embolism. Mayo Clinic. 2 January 2014. Web. 11 April 2014. http://www.mayoclinic.org/diseases-conditions/pulmonary-embolism/basics/definition/con-20022849

4. van Es, J, PL den Exter, AA Kaptein, CD Andela, PMG Erkens, FA Klok, RA Douma, ICM Mos, DM Cohn, PW Kamphuisen, MV Huisman, & S Middeldorp. (2013). Quality of life after pulmonary embolism as assessed with SF-36 and PEmb-QoL. Thrombosis Research, 132:500-505.

Image source: http://integral-options.blogspot.com/2012/02/pierre-cote-relative-happiness-index.html