REVIEW-Diagnosis of Deep Venous Thrombosis and Pulmonary Embolism JASON WILBUR, MD, and BRIAN SHIAN, MD

Diagnosis of Deep Venous Thrombosis and Pulmonary Embolism

JASON WILBUR, MD, and BRIAN SHIAN, MD, Carver College of Medicine, University of Iowa, Iowa City, Iowa

This is a quick review of the article found here 

Am Fam Physician. 2012 Nov 15;86(10):913-919.

     Venous thromboembolism  is basically a blood clot that can go to the legs, causing a DVT, or the lungs, causing a PE. DVT's occur twice as often, but if you have one, there is a greater chance that you may actually have both. The etiology is described commonly as "vichow's triad", which is hypercoagulability, alterations in blood flow, and endothelial injury. The WELLS criteria is commonly  used to determine pretest probability. It categorizes patients into low, medium, and high probability. It is used to determine if you want to order a D-dimer. This is a very sensitive test, so you only use it if you think the patient does NOT have a VTE and you want to rule it out. (You may come across an overzealous ER doc who orders this on every patient with a cough, thus you are stuck admitting the patient if the results come back indeterminate). So basically if you have a suspicion, and the WELLS criteria comes back intermediate or high, you are gonna order a compression ultrasound for a DVT. If it comes back negative, THEN you can do the D-dimer. Consider repeating the ultrasound in one week if the d-dimer is positive do confirm the patient is DVT free.
     PE is a little trickier because first you decide if the patient is hemodynamically stable. If they are unstable and critically ill, and they have a high pretest probability (WELLS), you can send them for an echocardiogram of your choice (transthoracic or transesophageal). If they are not critically ill, you have to option to send them for a multidetector CT if it is available, otherwise you cand send for an echo. If the patient cant do a CT, you can consider a V/Q scan. If the CT is positive or if the echo shows right ventricular disfunction, its a PE. If the CT comes back negative, but you know in your heart it a PE, you can continue to evaluate.  You can also consider a pulmonary angiogram if you want more testing, although it will expose the patient to a good amount of radiation. 
   One other thing I wanted to mention is that a patient with a PE may have "S1Q3T3 syndrome" on EKG. Its worth googling if you forgot what it means.
    This article has some nice algorithms and charts, so check it out!