What you describe is the intercuff block which is what Bier actually
described. The Procaine was flushed out at the end of the procedure. The
last paper I saw comparing the two techniques highlighted the cuff
discomfort that was more of a problem with the intercuff technique.
I enclose a summary that my pharmacy department did on Bier's block.
>
> Dear Dr McGlone
>
> I have some information which may help you as follows.
>
> Overview of pharmacokinetics of Biers block Local anaesthetic is
> given IV into the exsanguinated/tourniqueted limb. Most of it is rapidly
> absorbed into the surrounding tissue causing anaesthesia from its effect
> on the nerves. It is also bound to plasma proteins. When the cuff is
> removed the local anaesthetic remaining in the blood is released into the
> circulation potentially causing side effects.
> Prilocaine has the lowest % plasma protein binding (55%). Better than
> lignocaine (65%) or bupivacaine (95%). This is why prilocaine has the
> better safety margin and is the drug of choice. Once in the general
> circulation, prilocaine has a shorter half life than lignocaine again
> adding to the safety margin. The drug in the limb tissue then slowly
> diffuses back into the general circulation and is metabolised by the
> liver.
> Despite this, lignocaine is widely used for Bier's block and clinically
> rarely causes problems.
>
> Is the dose important ? The typical dose of lignocaine or prilocaine for
> Biers block is 2.5 to 4 mg/kg with a maximum of 250mg suggested for
> lignocaine. (Maybe a bit higher for prilocaine say 300-350 mg)
> This is conveniently supplied as 50mls of 0.5%.
> I would suspect that at larger doses, the proportion remaining in the
> blood would be proportionately larger as the surrounding tissue would
> becomes saturated.
>
> Is the volume important ? Larger volumes spread around the limb better
> but too high a volume may increase the pressure in the limb to the point
> where the cuff starts to leak. This causes systemic toxicity. For an arm
> the maximum volume should be 60 mls. Volumes less than 30 mls have been
> used but the onset is slower. Massage of the limb speeds this up but can
> also cause leakage at the cuff.
> So the desirable volume for an arm is probably 30-50 ml and maybe 40-60
> ml for a leg.
>
> What about preservative ? In an ideal world, injections where the dose
> is 15 ml or more should always be preservative free. This is less
> important with the modern day hydroxybenzoates than it was when phenol,
> cresol and the like were used.
>
> It is easy to see why 0.5% prilocaine preservative free 40-50 ml has been
> the gold standard in Britain for so long.
>
> Now that it has been discontinued (and I can confirm that ALL 0.5%
> citanest preparations are now discontinued. Personal communication with
> Lindsay Cameron at Astra Zeneca) the choices are to use a higher strength
> of prilocaine or change to lignocaine.
> Changing to lignocaine is complicated by the fact that 0.5% lignocaine
> (Xylocaine Astra-Zeneca) only comes in 20 ml vials and is currently having
> supply problems so cannot be purchased anyway.
>
> You have been informed that Astra Zeneca have no information on diluting
> 1% prilocaine injection and there are stability issues regarding tonicity
> and pH. This is true but is bloody minded and stupid.
> Citanest injection 1% is isotonic and adjusted to pH 6 (USP specifications
> for prilocaine are that it is between pH 6 and 7).
> Diluting this with normal saline (pH 5-7) will give a product which is
> isotonic and pH of 6. There will be no problem at all particularly as it
> would be used straight away.
>
> As to whether 20 mls of 1% prilocaine and 20 mls of normal saline are
> mixed in the syringe or injected sequentially into the arm, I doubt it
> makes much difference.
>
> Your ideal scenario would be for someone to start making 50ml preservative
> free vials of 0.5% prilocaine again.
>
> You may like to check out some of the hot links at the bottom if this
> e-mail.
>
> Jimmie
>
> ..............................................................
> mailto:[log in to unmask]
> ...............................................................
> Mr James Latona
> Drug Information Pharmacist
> Royal Lancaster Infirmary
> Ashton Road
> Lancaster
> LA1 4RP
> Telephone 01524 583401 Fax 01524 583407
> ***************************************************
> http://www.anes.med.umich.edu/tcairway/newsletter/9711/bier_block.htm
> Personal tale of the anaesthetist who has a bier's block
>
> http://units.ox.ac.uk/departments/anaesthetics/wfsa/html/u01/u01_003.htm
> Update in Anaesthesia article
>
> http://www.cma.ca/cjrm/vol-4/issue-4/0233.htm Canadian Medical Association
> article (quite a bit on volumes)
>
> http://www.esraeurope.org/abstracts/abstracts99/andres1.htm Spanish review
> article
----- Original Message -----
From: Rowley Cottingham <[log in to unmask]>
To: <[log in to unmask]>
Cc: <[log in to unmask]>
Sent: Friday, July 14, 2000 11:38 PM
Subject: Re: Bier's Block
> Has anyone else here heard of the BIVRA? This is a technique I worked with
John
> Hannington-Kiff (of guanethidine block fame) on about 15 years ago. It is
a low-volume
> version of the Bier's Block and may be a useful answer. It is an isolated
segment technique.
> You need TWO tourniquet sets.
>
> 1. Exsanguinate the arm by your usual method.
>
> 2. Fit one tourniquet in the usual way, and the other over the bulk of
muscle bellies below the
> radial head. Inflate both (top first) to 5 bar.
>
> 3. Insert a cannula at the elbow. We used Y-cans, but they have fallen out
of fashion a bit.
> The nervous may wish to insert a cannula in the opposite side.
>
> 4. Inject in exactly the same way as you would for a Bier's block and
observe that the local is
> now trapped between the two cuffs at the elbow. What is v useful is that
you only need half
> the volume.
>
> 5. Wait - maybe a little longer than with a normal Bier's, but certainly
not more than 5 minutes
> or so.
>
> 6. While waiting observe the perfect operating conditions in the hand - we
used to use this
> extensively for carpal tunnels, explorations and so on that simply can't
be done under a normal
> Bier's as the hand is too soggy to work on properly and oozes impossibly.
>
> 7. When firm tapping over the median nerve is painless perform your
manipulation.
>
> 8. Change the top cuff over onto the numb bit if that is your normal
practice.
>
> 9. Release both cuffs as you normally would, checking for return of
circulation as usual.
>
> Viola!
>
> Best wishes,
>
>
> Rowley Cottingham
>
> [log in to unmask]
>
>
>
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