One more
weapon
It's well established
that the period just
after induction —
known as redistrib-
ution — is when
patients are most at
risk for losing sub-
stantial body heat.
Redistribution
hypothermia is a
result of the vasodi-
lated state brought
on by anesthesia.
Body heat is redis-
tributed from the
core to the periph-
ery and ultimately
lost to the environ-
ment, unless vari-
ous mechanisms are
used to combat
loss.
One way to fight
heat loss is to keep
the operating room
warmer than nor-
mal during that
time, but that idea
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A P R I L 2 0 1 5 | O U T P A T I E N T S U R G E R Y . N E T
WARM WAYS
An Important Degree of Difference
H
ow do we know fluid warming works? Some
years back I led a study (tinyurl.com/orgoeuf)
of 38 women undergoing elective gynecologi-
cal surgery. The women were randomized into 2 groups.
One group was given fluid warmed to 42 degrees
(Celsius); the other group received room-temperature
fluid (about 21 degrees). All 38 were given general
anesthesia with isoflurane and all had standard operat-
ing room blankets and
surgical drapes.
We measured core temperatures at induction and
then at 15-minute intervals after induction. The result:
The warm-fluid group had higher core temperatures at
the end of surgery (36.2 degrees vs. 35.6 degrees). Also
35% of the room temperature group had final core tem-
peratures below 35.5 degrees, compared with none in
the warm-fluid group.
There was no difference in patient outcomes in this
relatively small sample, but we know that patients who
experience hypothermia are more susceptible to infec-
tions and less likely to be satisfied with their surgical
experience. Fluid warming, combined with other heat-
conservation methods, clearly helps maintain normoth-
ermia.
— Charles E. Smith, MD
