3 0 S U P P L E M E N T T O O U T P A T I E N T S U R G E R Y M A G A Z I N E J U LY 2 0 1 6
patients. Hypothermia increases the susceptibility
to infection through decreased tissue perfusion,
which leads to decreased antibiotic penetration to
the surgical tissue site. Hypothermia has also been
shown to alter white blood cell function, the body's
first line of defense against the organisms that can
cause SSIs.
When a patient's core temperature drops into
hypothermic range (below 36°C), delivery of
blood from the core to the periphery's larger vessels is altered in an attempt to
raise body temperature. Vasodilation properties of general anesthetics in the
early stages of sedation can cause a core-to-peripheral redistribution of body
heat, lowering the patient's core temperature. This is followed by heat loss
exceeding heat production while the unwarmed patient is on the OR table, fre-
quently exposed to cold ambient air. As the patient's core temperature contin-
ues to drop, decreased perfusion to the periphery ensues, which compromises
tissue perfusion, meaning antibiotics don't fully get to the site they're intended
to get to — you get some delivery, but you don't get optimal tissue penetration
in the hypothermic patient.
Hypothermia directly affects the circulatory, immune and coagulation sys-
tems. By virtue of its effects on tissue perfusion and improved oxygenation,
warming has been shown to reduce the risk of surgical site infection. It can
also reduce delayed healing and infection in traumatic or chronic wounds.
Just do it
Researchers have forged an undeniable connection between negative clinical
outcomes and hypothermia. Even mild hypothermia can cause serious adverse
effects. We all know that blankets, blowers, heated mattresses and warmed IV
fluids make patients feel snug against the cold of the OR and fight off the nega-
tive effects of general and regional anesthetics on perioperative normothermia.
Some patients
rate post-operative
shivering and the
feeling of cold
associated with it
as worse than
surgical pain.
