Comments on: No dental antibiotic prophylaxis for VP shunts. http://blogs.bmj.com/adc-archimedes/2008/02/12/dental-antibiotic-prophylaxis-for-vp-shunts/ Just another blogs.bmj.com weblog Sat, 11 Oct 2008 00:14:46 +0000 http://wordpress.org/?v=2.5.1 By: bphillips http://blogs.bmj.com/adc-archimedes/2008/02/12/dental-antibiotic-prophylaxis-for-vp-shunts/#comment-252 bphillips Fri, 15 Feb 2008 15:33:18 +0000 http://blogs.bmj.com/adc-archimedes/2008/02/12/dental-antibiotic-prophylaxis-for-vp-shunts/#comment-252 Ian - there is a feeling that you can get haematogenous spread of bugs into/onto VP shunts (though exactly how they did this - I can't imagine your average Staphlococcus answering such a question - I'm unsure about). Somewhere around 10-15% of shunts get infected mostly in the first year of placement; I don't know what proportion have an 'identified source'. I have never considered antibiotic prophylaxis for someone with a Port-a-cath pre-dentistry. I must ask a dentist next time I see one. Now, back to the VP shunts: I agree that the core question has to be "How does the risk of prophylactic antibiotics compare with the risk of post-procedural shunt infection?". (Out of interest - anyone know what the risk of endocarditis is for a simple VSD without prophylaxis, for example? Would give us a baseline on which to build any assessment of VP shunt prophylaxis.) Ian - there is a feeling that you can get haematogenous spread of bugs into/onto VP shunts (though exactly how they did this - I can’t imagine your average Staphlococcus answering such a question - I’m unsure about). Somewhere around 10-15% of shunts get infected mostly in the first year of placement; I don’t know what proportion have an ‘identified source’.

I have never considered antibiotic prophylaxis for someone with a Port-a-cath pre-dentistry. I must ask a dentist next time I see one.

Now, back to the VP shunts: I agree that the core question has to be “How does the risk of prophylactic antibiotics compare with the risk of post-procedural shunt infection?”.

(Out of interest - anyone know what the risk of endocarditis is for a simple VSD without prophylaxis, for example? Would give us a baseline on which to build any assessment of VP shunt prophylaxis.)

]]> By: iwacogne http://blogs.bmj.com/adc-archimedes/2008/02/12/dental-antibiotic-prophylaxis-for-vp-shunts/#comment-253 iwacogne Fri, 15 Feb 2008 14:38:45 +0000 http://blogs.bmj.com/adc-archimedes/2008/02/12/dental-antibiotic-prophylaxis-for-vp-shunts/#comment-253 I've not come across this question before, although I can understand why it has been asked. However, I wonder if things have got a little muddled with this dentist... - we know that if you brush your teeth you get a bacteraemia, moreso if you do more aggressive stuff to teeth - we know that if you've got turbulent flow or artificial devices in your heart that there can be patches where bacteria find it easier to settle - we know, therefore, that you need antibiotics to prevent bacterial endocarditis in this situation. However, with a VP shunt, what is the proposed mechanism? (I could understand a little more if it were a VA shunt, but I haven't seen one of those in years.) It would make more sense if we were talking about a portacath or something indwelling in the bloodstream - Bob, you use those all the time, do you advise bacterial prophylaxis? Do VP shunts get infected by haematogenous spread? Well, I guess so, although it would be hard to prove precisely the route of each infection. So, the interesting thing I'd like to see answered is: is there a plausible mechanism for increased infection rate, and if there is, what's the risk? And how does that compare to the (admittedly trivial) risk of a dose of antibiotics. I’ve not come across this question before, although I can understand why it has been asked. However, I wonder if things have got a little muddled with this dentist…

- we know that if you brush your teeth you get a bacteraemia, moreso if you do more aggressive stuff to teeth
- we know that if you’ve got turbulent flow or artificial devices in your heart that there can be patches where bacteria find it easier to settle
- we know, therefore, that you need antibiotics to prevent bacterial endocarditis in this situation.

However, with a VP shunt, what is the proposed mechanism? (I could understand a little more if it were a VA shunt, but I haven’t seen one of those in years.) It would make more sense if we were talking about a portacath or something indwelling in the bloodstream - Bob, you use those all the time, do you advise bacterial prophylaxis?

Do VP shunts get infected by haematogenous spread? Well, I guess so, although it would be hard to prove precisely the route of each infection.

So, the interesting thing I’d like to see answered is: is there a plausible mechanism for increased infection rate, and if there is, what’s the risk? And how does that compare to the (admittedly trivial) risk of a dose of antibiotics.

]]>