Bill,
I believe that Kristen meant embolize rather than propagate. In that case there is plenty of peer reviewed published research studies that show a significant reduction in PE & DVT with SCD( thigh high) vs control & no significant difference in PE & DVT when compared with pharmaceutical DVT prophylaxis without the complications associated with anticoagulants. The majority of the clinical trials were performed on general surgery, total hip & knee, & oncology patients.
Most patients actually find the rhythmic motion of the SCD soothing and generally don't have any difficulty sleeping. Generally patients are well medicated or to sick to notice the SCD. I know from personal experience the SCD didn't bother me at all until I was fully ambulatory than it was to much trouble to take off and put on when I needed to get up. 
Hopefully you will never have major surgery or become seriously ill, but if you do it's good to know that there is a device that will prevent you from getting a DVT or PE until you are able to ambulate.
BTW: The compression cycle( time to inflate each chamber and pressure in each chamber) was determined using Doppler ultrasound.
Mat,
The SCD is not a venadyne. The venadyne however is a competitor device, The SCD which is a multichamber device of either 3 calf length chambers, or  6 thigh length chambers. The chambers inflate in a sequential manner starting at the ankle. The cycle timing and chamber size regulate the pressure gradient between the chambers with the highest pressure at the ankle.
  
 
Carolyn M Semrow, RVS

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From: Bill Johnson <[log in to unmask]>
To: [log in to unmask]
Sent: Friday, October 12, 2012 4:45 PM
Subject: Re: SCD's on a patient with calf clot

Bill Johnson, Port Townsend, somewhere on the West Coast of the Americas
 
I understand the prinipals of "Squeezy Calf Devices" and would submit there is little if any research that links them with clot propagation, although that seems counter-intuative.  One fact involved might that moving flow in the veins not only reduces the chance of clotting but also enduces a limitation of clotting factors. 
 
I could be wrong, would not be he first time, but I cannot recall finding venous thrombosis in patients that were active, had no family history of ideopathic thrombosis/thrombophilia, travel confinement, or, most importantly trauma. 
 
I was never a "fan" of SCD's and disliked the time it took me to remove them to examine the limbs but I also took the time to carefully replace them.  I strongly doubt some applications did not result in subclinical PEs, but what does not kill you makes you stronger?
 
I only hope I will never need them, and wonder how I could sleep and recuperate with the darn things waking me all night...  I would rather get up and pace the floor.  I believe in the "calf pump".  But if that is not possible, pumping the calf might be the next best thing?

On Fri, Oct 12, 2012 at 1:11 PM, [log in to unmask] <[log in to unmask]> wrote:
sequential compression device

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----- Reply message -----
From: "Matthew Smith" <[log in to unmask]>
To: <[log in to unmask]>
Subject: SCD's on a patient with calf clot
Date: Fri, Oct 12, 2012 8:29 am


also known as  venodyne cuffs, basically a fancy blood pressure cuff that covers the entire calf and periodically squeezes to reduce the risk of DVT in non active patients, come to think of it I have no idea what SCD stands for, maybe "squeezy calf device"?

On Fri, Oct 12, 2012 at 7:26 AM, Luz Guzman Restrepo <[log in to unmask]> wrote:
SCD=?

Sent from my iPhone

On Oct 12, 2012, at 8:02 AM, Nancy Williams <[log in to unmask]> wrote:

There may be bi right answer but that was a darn good one. Thanks
 
From: UVM Flownet [mailto:[log in to unmask]] On Behalf Of Carolyn Semrow
Sent: Thursday, October 11, 2012 5:31 PM
To: [log in to unmask]
Subject: Re: SCD's on a patient with calf clot
 
Obviously the SCD is a DVT prophylaxis and traditionally the presence of an acute DVT is a contra-indication for its use. Certainly the age of the thrombus would make a difference. Older thrombus (hypoechoic with little change in echogenicity with external compression) are generally attached to the vein wall reducing the risk of embolization.
However, today DVT is commonly treated in the outpatient setting, with little change in patient activity, except leg elevation when sitting or laying down. The increase in venous velocity during walking is significantly higher than the velocities achieved with the SCD
An emboli from a  isolated short segment calf vein thrombus below the confluence of the tibial or peroneal veins or the tibial - peroneal confluence is small and most likely would not produce any symptoms. As the thrombus approaches the confluences they tend to also increase in length increasing the likelihood of symptoms and fatalities.
Also, it could be argued that continued use of the SCD in short segment isolated acute calf vein thrombosis may enhance recanalization.
Unfortunately, just like the treatment of calf vein thrombosis there is no right answer. As with the treatment of DVT an individualized plan based on patients risk factors, diagnostic results, and physical condition is probably the most appropriate.
Sorry I couldn't give you a black & white answer.   
 
Carolyn M Semrow, RVS
"A master, in the art of living, draws no sharp distinction
between his work and his play, his labor and his leisure,
his mind and his body, his education and his recreation.
He hardly knows which is which. He simply pursues his
vision of excellence through whatever he is doing and leaves
others to determine if he is working or playing. To himself
he always seems to be doing both."
Francois-René Chateaubriand (1768-1848)
 
 

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From: Kristen <[log in to unmask]>
To: [log in to unmask]
Sent: Thursday, October 11, 2012 3:28 PM
Subject: SCD's on a patient with calf clot

I am currently not working as a vascular tech but I'm in the hospital and there
is a patient on our floor who was diagnosed with a calf clot 2 days ago, the
report does not indicate if it is acute or chronic but when I was working with
the vascular dr's I know they typically did not take the SCD's off patients with
calf clots. The PT was asking questions about it because our dr d/c the SCD's
thinking it would cause the clot to propogate into a PE.

Please let me know your thoughts.
Thank you !

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