Monday, November 14, 2005

Pulmonary embolism and intervention

The cover of the Nov 1st Blue journal (AJRCCM 172(9)) showing a fibrosed thrombus reminded me how controversial treatment of this entity can be. I was interested in what others felt about the following. We all know that no study has demonstrated a change in mortality after thrombolytic therapy for acute massive PE. We also know that some of the beneficial paramters (such as right heart strain or PA pressure) are no different than just IV heparin after about 7 days. Nonetheless, does anyone feel that the lack of a mortality benefit may be as a result of the studies being underpowered? If this is the case, perhaps thrombolytics should be used as default pending a larger study (for massive PE without obvious bleeding risks). On the other hand, if the concensus is that nothing is proven with regards to mortality and thus thrombolytics are NOT indicated by default until that larger study comes along, should we ever administer it?
Now it gets even more sketchy when we consider surgical embolectomy. When do you consider this intervention? Some have argued that it absolutely has no place. Others will ship everyone with a b/l saddle embolus out to the Mayo for embolectomy.
I think there is not a lot of convincing data out there for anything other than good old fashioned anticoagulation and IV fluids (and some prayer).
What do you all do when you get the call about a patient with acute massive P.E.?

4 comments - CLICK HERE to read & add your own!:

Arenberg said...

Jeff, may take on this is that the burden of proof is on those who favor the intevention, and not the otehr way around. I base this on the fact that there is a fairly well defined risk to thrombolytics, with a benefit that is at best ill defined (except in people who are not actively in shock or overt circulatory collapse as a result of their PE). Your point about the studies on this area being underpowered is good.

The one study that made it into the NEJM (http://content.nejm.org/cgi/content/full/347/15/1143)

was so poorly conceived and executed as to call into question how the hell it ever got published in such a high impact journal. It was irresponsible of theeditors to accept that paper in my opinon, as the the results of that paper really really rely on a circular argument if you believe that thrombolytics are benefiocial.

Baleeiro said...

Jeff, remember that the reason thrombolyitics are NOT the default is not that they are equivalent to IV UFH: they are equivalent with an increased risk of complications. It´s hard for me to argue for thrombolytics based on RV dysFxn´and indirect markers since, as you pointed out, those parameters are the same after a week...

Mike L said...

Doug and Carlos's points are excellent.
The way our medical system works is that we need data to support the use of a therapy before its institution. If we did not do this, I suppose I could start drumming up support for the use of statin drugs in sarcoid. They have antiinflammatory properties, right?
Another controversial question is what to do with the patient with submassive PE and residual LE clot. Do you put in a filter or just anticoagulate? The data can be manipulated to support both.

Jeff H said...

I also agree that the burden is on the intervention. The study that Doug cited is horrible. It does a great job showing that patients with a PE who receive thrombolytics initially are less likely to need thrombolytics than patients with PE who did not receive thrombolytics.

Suction embolectomy? Come on. If they are in shock, they get lytics, if they are not, they get heparin. In fact, I just had a patient in our ICU who got an interventional radiology procedure/suction embolectomy. It worked very well, as the previously stable patient showered emboli, had a PEA arrest, and died.