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How the blinding was done in the BNAC 20 patient trial

Posted: Sat May 14, 2011 2:52 pm
by Cece
•Sealed and numbered envelopes with pre-stated treatments (sham vs angioplasty) are opened upon initiation of selective venography

•Patients are consciously sedated using Fentanyl and Versed intravenously till they are no longer actively conversing, yet are easily arousable when spoken to.

•Relatively loud music of patients choice is played so that procedural conversation is inaudible

•The operating room staff is acutely aware of blinding requirements and has been trained to avoid any loud procedure related conversation
The X-ray shields are covered with opaque sterile covers to avoid glancing by patients

•The monitors are angled to avoid any incidental visualization by patient

•All patients receive a rigorous sternal rub (painful stimulus) upon insertion of angioplasty balloon regardless of inflation

•A blindness assessment survey is administered the following morning prior to discharge
http://www.bnac.net/wp-content/uploads/ ... 7-2011.pdf

How interesting! "A rigorous sternal rub" was done for all patients when the ballooning was done. Versed was used too. Loud music so the patient doesn't hear anything.

Re: How the blinding was done in the BNAC 20 patient trial

Posted: Sat May 14, 2011 4:29 pm
by HappyPoet
Cece wrote:How interesting! "A rigorous sternal rub" was done for all patients when the ballooning was done. Versed was used too. Loud music so the patient doesn't hear anything.
Thanks, Cece. You're right -- this is very interesting!

I'm not sure what "a rigorous sternal rub" is. I take it, though, (and hope!) that this 'painful stimulus' does not affect the catheter nor the balloon inside the vein.

Posted: Sat May 14, 2011 6:37 pm
by Cece
I read it wrong, it says the painful rub was when the balloon catheter was inserted, not when the ballooning would/wouldn't occur. I guess it's so that if the patient is semi-conscious, they remember some pain as part of the procedure.

Posted: Sun May 15, 2011 8:23 am
by HappyPoet
Cece wrote:I read it wrong, it says the painful rub was when the balloon catheter was inserted, not when the ballooning would/wouldn't occur. I guess it's so that if the patient is semi-conscious, they remember some pain as part of the procedure.
Thanks Cece. I misread it, too.

I understand firsthand why they're trying to create a painful memory, but I don't understand how they're actually performing the "rigorous sternal rub." I know we don't have these answers, but I have questions like, "Do they keep rubbing until the patient complains of pain?" "Are patients told beforehand that they will be painfully rubbed?" "For how long will the patient experience the painful rubbing?" "Is there a preset upper time limit for the rubbing?"

:D

Posted: Sun May 15, 2011 1:02 pm
by ozarkcanoer
This "painful rub" is interesting to me because I have had balloon venoplasty twice and had very little pain except when the balloon was inflated. But I guess a naive patient would not know when to expect pain so whenever/whatever pain occurs then the patient who gets ballooning as opposed to the patient who does NOT get ballooning may both experience somewhat the same thing during the real or sham procedures. I only experienced pain on one side, when the stent was expanded, and they immediately gave me pain reliever. Now I know what to expect and would not be a good candidate for a clinical trial of this kind (in addition to being too old, LOL).

ozarkcanoer