Evaluation of qCON and qNOX indices in pediatric surgery under general anesthesia.

Background and Aims: The objective of the study was to evaluate the performances of qCON and qNOX indices in pediatric populations undergoing surgery under general anesthesia (GA), focusing on the induction and recovery periods. Both the indices are derived from electroencephalogram (EEG) and implemented in the CONOX monitor (Fresenius Kabi, Germany). Material and Methods: After approval of the institutional ethics committee, this prospective observational study was conducted in pediatric patients of either sex in the age group of 1-12 years belonging to the American Society of Anesthesiology (ASA) grade I and II undergoing elective surgery under GA. Anesthetic technique was GA with or without regional analgesia (RA). All patients underwent inhalation induction and maintenance using sevoflurane. Patients were monitored with the use of a CONOX monitoring system (Fresenius Kabi, Germany), connected via a set of electrodes placed over the forehead. qCON and qNOX scores were recorded during awake (on operating table premedicated with oral midazolam 0.5 mg/kg), at induction, at loss of eyelash reflex, intubation/laryngeal mask airway (LMA) insertion, before and after regional anesthesia, surgical incision, at cessation of anesthesia, emergence, extubation, and eye-opening. Registered results were also analyzed compared with the minimum alveolar concentration of sevoflurane (MAC). Results: A total of 46 pediatric patients were enrolled in the study with a mean age of 5.6 years. All the patients were either ASA I or II. There was a simultaneous fall and rise of qCON and qNOX upon induction and recovery, respectively. There was a rise in qNOX with surgical incision irrespective of RA. However, there was a greater rise in qNOX following surgical incision in those who did not receive RA (P = 0.33) Also both qCON (P = 0.06) and qNOX (P = 0.41) were poorly correlated with MAC values of sevoflurane during GA in the pediatric population. Conclusions: Both qCON and qNOX values change predictably with changes in the conscious level and with different noxious stimuli. Further studies are required to confirm the findings taking into account the postoperative assessment of delirium and recall of intraoperative events.

Real-time evaluation of the independent analgesic efficacy of dexmedetomidine.

BACKGROUND: Dexmedetomidine has analgesic properties, but the intraoperative analgesic effect of dexmedetomidine is often masked by the effects of other general anaesthetics. Therefore, the degree to which it reduces intraoperative pain intensity remains unclear. The objective of this double-blind, randomised controlled trial was to evaluate the independent intraoperative analgesic efficacy of dexmedetomidine in real-time. METHODS: This single-centre study enrolled 181 patients who were hospitalised for below-knee orthopaedic surgeries between 19 January 2021 to 3 August 2021 were eligible for this is single-centre study. Peripheral neural block was performed on patients scheduled for below-knee orthopaedic surgeries. Patients were randomly assigned to the dexmedetomidine or midazolam group and were intravenously administered with 1.5 µg kg-1 h-1 dexmedetomidine or 50 µg kg-1 h-1 midazolam, respectively. The analgesic efficacy was evaluated using the real-time non-invasive nociception monitoring. The primary endpoint was the attainment rate of the nociception index target. The secondary endpoints included the occurrence of intraoperative hypoxemia, haemodynamic parameters, the consciousness index, electromyography and patient outcomes. RESULTS: On Kaplan-Meier survival analysis, the defined nociception index target was attained in 95.45% and 40.91% of patients receiving dexmedetomidine and midazolam, respectively. Log-rank analysis revealed that the dexmedetomidine group attained the nociception index target significantly faster and the median attainment time of the nociception index target in the dexmedetomidine group was 15 min. Dexmedetomidine group was associated with a significantly lower incidence of hypoxemia. There was no significant difference in blood pressure between the dexmedetomidine and midazolam groups. Further, the dexmedetomidine group had a lower maximum visual analogue scale score and lower analgesic consumption postoperatively. CONCLUSIONS: Dexmedetomidine has independent analgesia and systemically administered as an adjuvant agent has better analgesic efficacy than midazolam without severe side effects. TRIAL REGISTRATION: clinicaltrial.gov Registry Identifier: NCT-04675372.Registered on 19/12 /2020.

Multiparametric Monitoring of Hypnosis and Nociception-Antinociception Balance during General Anesthesia-A New Era in Patient Safety Standards and Healthcare Management.

The development of general anesthesia techniques and anesthetic substances has opened new horizons for the expansion and improvement of surgical techniques. Nevertheless, more complex surgical procedures have brought a higher complexity and longer duration for general anesthesia, which has led to a series of adverse events such as hemodynamic instability, under- or overdosage of anesthetic drugs, and an increased number of post-anesthetic events. In order to adapt the anesthesia according to the particularities of each patient, the multimodal monitoring of these patients is highly recommended. Classically, general anesthesia monitoring consists of the analysis of vital functions and gas exchange. Multimodal monitoring refers to the concomitant monitoring of the degree of hypnosis and the nociceptive-antinociceptive balance. By titrating anesthetic drugs according to these parameters, clinical benefits can be obtained, such as hemodynamic stabilization, the reduction of awakening times, and the reduction of postoperative complications. Another important aspect is the impact on the status of inflammation and the redox balance. By minimizing inflammatory and oxidative impact, a faster recovery can be achieved that increases patient safety. The purpose of this literature review is to present the most modern multimodal monitoring techniques to discuss the particularities of each technique.

Predicting acute postoperative pain by the Qnox score at the end of surgery: a prospective observational study.

BACKGROUND: The QNox score (Quantium Medical S.L., distributed by Fresenius Kabi) has recently been introduced as a tool to quantify intraoperative analgesia. Being based on the analysis of electroencephalographic data, QNox is distinctly different to other methods of nociception monitoring that rely almost entirely on the assessment of sympathetic activity. However, there are currently no published data to validate use of QNox in a clinical setting. We investigated the value of pre-arousal QNox data at the end of surgery for prediction of acute postoperative pain in the PACU. METHODS: A total of 150 patients scheduled for non-emergency surgery under sevoflurane-opioid general anaesthesia were included in the study. At the end of surgery but before patient arousal, QNox was measured minutely for 5 min. After admission to the recovery room, pain scores (numeric rating scale [NRS], 0-10) were obtained 5 minutely for 15 min. RESULTS: Data from 144 patients were analysed. QNox before arousal showed no correlation (ρ=0.057) with acute postoperative pain in the PACU. Furthermore, the score was found to have no value for the prediction of acute postoperative pain (area under the receiver operating curve, 0.501; 95% confidence interval, 0.406-0.597). CONCLUSION: QNox at the end of surgery before arousal showed no association with and allowed no prediction of acute pain in the PACU. CLINICAL TRIAL REGISTRATION: ACTRN12618001662257.

The effect of hypothermia during cardiopulmonary bypass on three electro-encephalographic indices assessing analgesia and hypnosis during anesthesia: consciousness index, nociception index, and bispectral index.

The depth of anesthesia is commonly assessed in clinical practice by the patient's clinical signs. However, during cardiopulmonary bypass and hypothermia, common symptoms of nociception such as tachycardia, hypertension, sweating, or movement have low sensitivity and specificity in the description of the patient nociception and hypnosis, in particular, detecting nociceptive stimuli. Better monitoring of the depth of analgesia during hypothermia under cardiopulmonary bypass will avoid underdosage or overdosage of analgesia, especially opioids. Induced hypothermia has a multifactorial effect on the level of analgesia and hypnosis. Thermoregulatory processes appear essential for the activation of analgesic mechanisms, ranging from a physiological strong negative affiliation between nerve conduction velocity and temperature, until significant repercussions on the pharmacological dynamics of the analgesic drugs, the latter decreasing the clearance rate with a subsequent increase in the effect-site concentrations. Under the hypothesis that deep hypothermia induces massive effects on the analgesia and hypnosis levels of the patient, we studied whether hypothermia effects were mirrored by several neuromonitoring indices: two hypnosis indices, consciousness index and bispectral index, and a novel nociception index designed to evaluate the analgesic depth. In this clinical trial, 39 patients were monitored during general anesthesia with coronary atherosclerosis cardiopathy who were elective for on-pump coronary artery bypass graft surgery under hypothermia. The changes and correlation between the consciousness index, bispectral index, and nociception index with respect to the temperature were compared in different timepoints at basic state, during cardiopulmonary bypass and after cardiopulmonary bypass. While the three neuromonitoring indices showed significant correlations with respect to the temperature, the nociception index and consciousness index showed the strongest sensitivities, indicating that these two indices could be an important means of intraoperative neuromonitoring during induced hypothermia under cardiopulmonary bypass.

Monitoring of nociception, reality or fiction? / Monitorización de la nocicepción, ¿realidad o ficción?

There are currently various projects underway that attempt to monitor the nociceptive responses caused by surgical stress and ensure patients the best analgesic conditions. The systemic response to surgical stress has repercussions in the postoperative period, such as worse pain control, delayed recovery, greater complications, longer stay in resuscitation and hospital units, and increased healthcare costs. However, treatment with higher doses of opioids than necessary may lead to slower awakening, increased drowsiness and adverse effects, as well as situations of postoperative opioid-induced hyperalgesia. There are 2 large groups of nociceptive monitoring according to the origin of the theoretical objective of monitoring response to the stimulus, that may derive from changes in the electroencephalogram or the response of the autonomic nervous system.