Department of Cardiac Surgery, 3rd Faculty of Medicine, Charles University, Prague and University Hospital Kralovske Vinohrady, Prague, Czech Republic.
Department of Anaesthesia, Leeds Teaching Hospitals, United Kingdom.
Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2024 Mar;168(1):62-67. doi: 10.5507/bp.2022.045. Epub 2022 Nov 2.
Monitoring nociception during general anaesthesia remains a substantial challenge. The Conox monitor uses two EEG indices, the qCon and the qNox. The qNox refers to the probability that a nociceptive stimulation triggers a movement of the patient and the response probability of reaction to nociceptive stimulation. We decided to test the feasibility of monitoring the qNOX index during adult cardiac surgery and to investigate whether this index correlates with hemodynamic and hormonal signs of nociceptive stimulation.
We enrolled 19 patients undergoing elective cardiac surgery. These were randomised to 2 groups receiving different doses of sufentanil via target controlled infusion: group A (n=9) 0.25 ng/mL and group B (n=10) 0.75 ng/mL. All patients were maintained at the same depth of anaesthesia. We recorded the Conox monitor indices (qNOX, qCON, electromyographic), hemodynamic variables and plasmatic levels of cortisol and noradrenaline.
There was significantly higher blood pressure (P=0.013) and plasmatic cortisol (P=0.003) in group A and a significant increase in plasmatic noradrenaline with increasing intensity of surgical stimulation in both groups: A (P=0.001), B (P=0.008). We found no significant corresponding changes in the qNOX index. There was a positive correlation between qNOX and hemodynamic signs of stimulation (P=0.012) and between the qNOX and EMG indices (P=0.013) after endotracheal intubation, but not later after EMG index dropped.
Our results do not support the assumption that signs of nociceptive stimulation during adult cardiac surgery will be reflected by the qNOX index. This may be related to compounding of qNOX processing and use of muscle relaxants. Further investigation on this field is needed.
在全身麻醉期间监测伤害感受仍然是一个重大挑战。Conox 监测仪使用两个 EEG 指数，qCon 和 qNox。qNox 是指伤害性刺激引发患者运动的概率和对伤害性刺激的反应概率。我们决定测试在成人心脏手术期间监测 qNOX 指数的可行性，并研究该指数是否与伤害性刺激的血流动力学和激素迹象相关。
我们纳入了 19 名接受择期心脏手术的患者。这些患者被随机分为两组，通过靶控输注接受不同剂量的舒芬太尼：A 组（n=9）0.25ng/ml 和 B 组（n=10）0.75ng/ml。所有患者均保持相同的麻醉深度。我们记录了 Conox 监测仪指数（qNOX、qCON、肌电图）、血流动力学变量以及皮质醇和去甲肾上腺素的血浆水平。
A 组的血压（P=0.013）和皮质醇（P=0.003）显著升高，两组的去甲肾上腺素随着手术刺激强度的增加而显著增加：A 组（P=0.001），B 组（P=0.008）。我们没有发现 qNOX 指数有显著的相应变化。qNOX 与刺激的血流动力学迹象之间存在正相关（P=0.012），与肌电图指数之间也存在正相关（P=0.013），但在肌电图指数下降后则没有。
我们的结果不支持这样的假设，即成人心脏手术期间的伤害性刺激迹象将反映在 qNOX 指数上。这可能与 qNOX 处理和使用肌松剂的复合有关。需要对此领域进行进一步的研究。
