From the Pain Mechanisms Lab, Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, North Carolina.
Anesthesiology. 2018 Oct;129(4):778-790. doi: 10.1097/ALN.0000000000002325.
WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Cognitive capacity may be reduced from inflammation, surgery, anesthesia, and pain. In this study, we hypothesized that incision-induced nociceptive input impairs attentional performance and alters neuronal activity in the prefrontal cortex.
Attentional performance was measured in rats by using the titration variant of the 5-choice serial reaction time to determine the effect of surgical incision and anesthesia in a visual attention task. Neuronal activity (single spike and local field potentials) was measured in the medial prefrontal cortex in animals during the task.
Incision significantly impaired attention postoperatively (area under curve of median cue duration-time 97.2 ± 56.8 [n = 9] vs. anesthesia control 25.5 ± 14.5 s-days [n = 9], P = 0.002; effect size, η = 0.456). Morphine (1 mg/kg) reduced impairment after incision (area under curve of median cue duration-time 31.6 ± 36.7 [n = 11] vs. saline 110 ± 64.7 s-days [n = 10], P < 0.001; η = 0.378). Incision also decreased cell activity (n = 24; 1.48 ± 0.58 vs. control, 2.93 ± 2.02 bursts/min; P = 0.002; η = 0.098) and local field potentials (n = 28; η = 0.111) in the medial prefrontal cortex.
These results show that acute postoperative nociceptive input from incision reduces attention-related task performance and decreases neuronal activity in the medial prefrontal cortex. Decreased neuronal activity suggests nociceptive input is more than just a distraction because neuronal activity increases during audiovisual distraction with similar behavioral impairment. This suggests that nociceptive input and the medial prefrontal cortex may contribute to attentional impairment and mild cognitive dysfunction postoperatively. In this regard, pain may affect postoperative recovery and return to normal activities through attentional impairment by contributing to lapses in concentration for routine and complex tasks.
炎症、手术、麻醉和疼痛可能会导致认知能力下降。在这项研究中，我们假设切口引起的伤害性传入会损害注意力表现，并改变前额叶皮层中的神经元活动。
通过使用 5 选择序列反应时间的滴定变体，在大鼠中测量注意力表现，以确定手术切口和麻醉在视觉注意任务中的影响。在动物进行任务时，测量内侧前额叶皮层中的神经元活动（单峰和局部场电位）。
手术后切口显著损害注意力（中位数线索持续时间的曲线下面积 97.2 ± 56.8 [n = 9] vs. 麻醉对照 25.5 ± 14.5 s-days [n = 9]，P = 0.002；效应量，η = 0.456）。吗啡（1 mg/kg）减少切口后的损伤（中位数线索持续时间的曲线下面积 31.6 ± 36.7 [n = 11] vs. 盐水 110 ± 64.7 s-days [n = 10]，P < 0.001；η = 0.378）。切口还降低了细胞活动（n = 24；1.48 ± 0.58 与对照相比，2.93 ± 2.02 爆发/分钟；P = 0.002；η = 0.098）和内侧前额叶皮层的局部场电位（n = 28；η = 0.111）。
这些结果表明，来自切口的急性术后伤害性传入会降低与注意力相关的任务表现，并降低内侧前额叶皮层中的神经元活动。神经元活动的减少表明伤害性输入不仅仅是一种干扰，因为在具有类似行为损伤的视听干扰下，神经元活动会增加。这表明伤害性输入和内侧前额叶皮层可能与术后注意力障碍和轻度认知功能障碍有关。在这方面，疼痛可能通过对常规和复杂任务的注意力不集中导致失误，从而通过注意力障碍影响术后恢复和恢复正常活动。
