Eur J Pain. 2005 Apr;9(2):105-8.
Opioid analgesia in the newborn.
Nandi R1, Fitzgerald M.
Abstract
Pain in neonates is now well established. Studies of the developmental
neurobiology of pain have revealed that pain processing in the immature is
very different from that in the mature nervous system. Neonates undergo
considerable maturation of peripheral, spinal and supraspinal afferent pain
transmission over the early postnatal period but are able to respond to
tissue injury with specific behaviour and with autonomic, hormonal and
metabolic signs of stress and distress. Opioid analgesia is now
widely used in neonates. There is evidence that morphine requirements may
be low in the youngest patients. Sensory threshold testing in rat pups has
shown that the analgesic potency of systemic morphine mechanical stimulation
is significantly greater in the neonate and declines with postnatal age.
The changing morphine sensitivity in the postnatal period may be part of
a general reorganization in the structure and function of primary afferent
synapses, neurotransmitter/receptor expression and function and excitatory
and inhibitory modulation from higher brain centres. Importantly opioid
receptor expression undergoes significant developmental regulation - mu opioid
receptors, observed to be exuberantly expressed in the neonatal rat,
have been found to be functional. These findings have important implications
for the human
neonate as they provide a possible explanation for the differences in morphine
requirements observed in the youngest patients. The study of the underlying
mechanisms of pain and analgesia in development has enabled important changes
in clinical practice. However, pain in the newborn remains poorly understood
and continued research and intensive study in this area is essential for
further effectiveanalgesic intervention and the discovery of new targets for
therapy.
我解讀的部分如下
1.Pain in neonates is now well established. Studies of the developmental
neurobiology of pain have revealed that pain processing in the immature is
very different from that in the mature nervous system.
主要在講神經構造的發展成熟度，會導致疼痛的發生過程（機轉）非常不一樣
2.Neonates undergo considerable maturation of peripheral, spinal and
supraspinal afferent(傳入的) pain transmission over the early postnatal
period but are able to respond to tissue injury with specific behaviour and
with autonomic, hormonal and metabolic signs of stress and distress.
疼痛在小兒身上，會因造成某種身體上的壓力，會導致賀爾蒙及代謝的現象發生
3. There is evidence that morphine requirements may be low in the youngest
patients. Sensory threshold testing in rat pups has shown that the analgesic
potency of systemic morphine mechanical stimulation is significantly greater
in the neonate and declines with postnatal age
證據顯示，嗎啡的需求劑量，在年紀越小的小朋友需求越低。在老鼠的疼痛閾值試驗中，
顯示出，因嗎啡刺激所造成止痛的強度，在neonate上是有顯著的好，
並且declines with postnatal age。(什麼是declines with postnatal age?)
4. Importantly opioid receptor expression undergoes significant
developmental regulation - mu opioid receptors, observed to be exuberantly
expressed in the neonatal rat, have been found to be functional.
These findings have important implications for the human neonate as they
provide a possible explanation for the differences in morphine requirements
observed in the youngest patients.
這段在說，嗎啡的受體，在剛出生的小鼠有顯著的成熟，並且是有功能的。
這個發現說明了，為什麼在年紀小的病人，嗎啡的需求量會差異這麼大。
以上就是我所瞭解的部分，不過是非常殘缺不全的理解
請版上大大幫忙了
感謝