One of the important functions of nervous system is to supply the information related to the injury. Therefore, for various kinds of injuries, to feel pain is thought to be the part of this important function. There are A-fiber (Type ⅠAMHs, Type
ⅡAMHs) & C-fiber (CMHs) which respond to the mechanical & thermal stimuli as the nerve fibers of peripheral unit performing this function. The phenomena expressed to us by these stimuli are those reaction like the increase of heart rate and the
elevation of lood pressure by stimulation of the autonomic nervous system as well as pain. As it is, using these reactions which are the most popular parameter of pain expression during anesthesia, we make the depth of anesthesia deeper or use
analgesics as adjuvants.
In general, there are many kinds of analgesics for adjuvants of anesthesia or for elimination of postoperative pain. To compare the effciency of those analgesics toward pain, the authors studied the inhibitory effects of analgesics on the
increase
of
pulse rate and mean arterial pressure evoked by the thermal and mechanical stimulations in rats.
We used the agents popularly used in nowadays 1) Tramadol HCI, known as a potent analgesics, 2) Nalbuphine, antagonist of opioids, 3) Meperidine and Morphine, opioids -to compare the efficiency of hemodynamic augumentation by the thermal and
mechanical
stimulations with the control group.
@ES The results were as followa:
@EN 1) The inhibitory effects on the increase in pulse rate and mean arterial arterial pressure evoked by the stimulations were in the decreasing order of morphine, meperidine, nalbuphine, and tramadol.
2) The inhibitory effect of morphine on the increment of pulse rate and mean arterial pressure was evident.
3) Meperidine and nalbuphine, not so much potent as morphine in inhibitory also inhibit to a considerable degree.
4) In the case of tramadol, the increament of pulse rate evoked by the stimulations were inhibited to some extent, but it was proven not to inhibit the elevation of mean arterial pressure.
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