the michigan risk score

I hear it everywhere I go. 

"I wish I could have known that patient would have had a DVT..." "If only I could have done something different before ordering or placing the PICC..." "I had this feeling they were high risk, but I wasn't sure and it seemed like a reasonable choice..."

All of these are aphorisms of the sinking feeling when you get the call: the ultrasound is positive, and the patient has a PICC-DVT.

We know there are evidence-based ways to prevent this:

• Choosing the appropriate device
• Preserving the catheter to vein ratio (using the smallest catheter or finding the largest vein are two well trialed strategies)
• Making sure the catheter tip is centrally positioned

But even if you follow all of the above recommendations - some patients will still have a PICC-related DVT.

Is there a way to know?

I'm referring specifically to a crystal ball here - a way to be able to predict who will have a DVT and who won't, if you follow best practice.

That is what the Michigan Risk Score (MRS) does....

We looked at over 20,000 patients and separated those that had a PICC DVT from those that did not. Then - we went back in time to before the PICC was placed. What was it about those that had a DVT that different substantially enough from those that did not? Was there a signal?

We certainly found one - and published this for others to see/use. Here are the risk factors:
1. Presence of another CVC when the PICC was placed.
2. WBC count > 12, 000 at the time of PICC insertion
3. Number of PICC lumens
4. History of Venous Thromboembolism
5. Active cancer

Selecting each of these displays a final score and risk class (I-IV, IV being highest) that can then be used to determine whether the PICC is the best choice for the patient. This is particularly true for those with cancer or patients who have had prior VTE - since avoidance can be the best treatment in this subset as shown in the picture below.

There are a number of resources that can make this easier for you to apply on a day-to-day basis - before the PICC is ordered or placed (see below for links).

The MRS is now being validated through the leadership of a number of brilliant investigators and committed hospitals in Brazil. The project will likely take 18-24 months but will provide invaluable information about how the MRS performs and whether it can be improved. It's through tools like this - the proverbial crystal ball - that our patients will be best served. 

See more information about the MRS and find a handy calculator here.
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