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At 12:04 AM 3/21/1996 -0500, Automatic digest processor wrote:
 
>
>Topics of the day:
>
>  1. MYTHS IN EM
 
>Date:    Tue, 19 Mar 1996 14:02:44 EST
>From:    DR MARTIN I HERMAN <[log in to unmask]>
>Subject: Re: MYTHS IN EM
>
>-- [ From: Martin Herman * EMC.Ver #2.10P ] --
>
>Myth 1----I don't routinely restart Prehospital lines ( I am a
>Pediatric Emergency DOC) but most of the time the lines are infiltrated
>and have to be restarted. OR the medics couldn't get a line at all and
>the child comes in with an IO. FOr adults ( when I did adult work) Iv's
>were left in place but the lines were replaced because the solu sets
>were not comapatible with the pumps we used, the lines had to be
>changed out. All IV are changed every 3 days because of infection
>control. Paramedics sholdn't have such thin skin about their lines
>being replaced.
>
******I agree that faulty lines need replacement and that one must comply
with applicable policy standards regarding duration of dwell for the cannula
site.   The "myth" discussed was the folkloric practice of *automatically*
discontinuing *functional* lines at the first feasible moment (<24 hours)
*without signs of infection* solely because the line had been started by an
emergency provider (even hospital-based) and was *presumed* to have
*less-than-aseptic-technique* which I don't believe can be generally supported.
 
>Myth 2 ----Large bore IV's for blood transfusions---I agree blodd can
>be givien through small bore IV's but not as fast. In Peds the vol
>needed to be administered is far less than in the hemodynamically
>compromised adult and for kids the vol can be given in small canulas
>quickly. In adults the vol is so much larger that the time limitation
>makes it more practical to place large bore IV's.
 
*****The "myth" was that *all* blood-products given to *hemodynamically
stable* adults *require* a "large" line.  The volume may be greater, but may
be adequately transfused with an appropriate infusion pump quite
successfully.  If there is significant potential for hemodynamic
deterioration, than it would not be appropriate to rely solely upon a small
line.  However, the patient who is otherwise stable but needs transfusion
should not be unduly tortured in pursuit of a large vessel that is not present.
 
>Myth 3----Drawing blood through small IV's-----I disagree. A lot of my
>patients have potassiums in the 5-6 range when drawn through the
>smaller needles. We also see a lot of redraws requested because of
>clotting. The viscosity of the blood is a factor and in the anemic
>patient the smaller needle is less of  problem. We encourage our
>phlebotomists to use as large a bore needle as possible to draw,
>thoufgh sometimes they use a 25 it's rare. Most often a 21g is used on
>the smaller children and an 18 on the teenagers.
>
 
*****Certainly hemolysis can and does occur, however, I and others, have had
hemolysis reported by the laboratory even when drawn through 18's, 16's, and
14's.  What appears to be significant is how turbulent or difficult that
flow might have been.  It helps the situation if the draw can be gentle, or
an adequate pool of blood [tourniquet time can also produce hemolysis] be
engorged within the vein from which the cannula must sip, or, in those times
when one must rely also upon the replenishment of that pool (as it is drawn)
by distal blood flowing around the cannula it helps that the cannula not so
completely take up the lumenal space that the cells are damaged as they
squeeze between the intima and the cannula.  I have found that by carefully
assessing these factors as I plan my access, that often one's success occurs
by going down a size of cannula.  Results have been better sometimes than
the previous draw from a larger needle.  Remember also that rough-handling
of the drawn specimen can hemolyze, just as we have all had CBCs and COAGs
reported as clotted despite being in a tube of anti-coagulant from
inadequate mixing or delay in transfer of the specimen.
 
*****I appreciate your comments as we learn by sharing experiences.  I hope
the above is a useful clarification.  Thanks,
 
                                                                        Tom
 
Tom Trimble, RN CEN
[log in to unmask]
 
The URL for the PED-EM-L Web Page is:
  http://www.brown.edu/Administration/Emergency_Medicine/ped-em-l.html