Understanding Anesthesiology - The Global Regional Anesthesia ...

Shivering
Shivering is a response controlled via the hypothalamus
aimed at generating endogenous heat. The cost of
this heat production is a fourfold increase in oxygen
consumption and carbon dioxide production. This can
precipitate myocardial ischemia or respiratory failure
in patients with limited coronary or ventilatory reserve.
Most commonly, shivering is a direct response to hypothermia
and is best treated with aggressive rewarming
techniques such as forced air warming systems. In the
PACU, one often observes normothermic patients who
shiver. This is a poorly understood effect of residual
volatile gases and often abates with the administration
of small doses of intravenous meperidine.
Pain
Pain is a consequence of all but the most minor surgical
procedures. Aside from its inherent unpleasantness, it
can lead to hypertension, tachycardia, myocardial ischemia
and respiratory failure. Post-operative pain is most
effectively approached through preventive measures
taken in the operating room. Occasionally, this is
achieved with a nerve block or the administration of
central neuraxial local anesthetics and/or opioids.
More commonly, however, the anesthesiologist titrates
the dose and timing of intravenous opioids to anticipate
an awake, comfortable patient at the end of the
procedure. A brief discussion of the methods of continued
post-operative pain control follows in the next
chapter.
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