Introduction
The global incidence of cardiac arrhythmia in 2016 was 43.6 mln people and in 2019 — 59.7 mln people [1]. The type of arrhythmia, heterogeneity and variability of traumatic and reflexogenic effects, the interventional experience of the centers and the availability of an anesthesia service as well as the age of patients and comorbid pathology determine the choice of anesthetic and the depth of sedation during catheter ablation (CA) [2]. Catheter radiofrequency (RF) ablation for cardiac arrhythmia is a painful procedure. According to Münkler et al., 7.7 % of patients reported procedural pain, and 16 % reported side effects, such as post-operative nausea and headache episodes [3]. A possible cause of procedural pain could be the increased activity of cerebral cortex areas associated with pain, presumably due to inadequate blocking of afferent nociceptors in the cardio-vascular system [4]. Intraoperative nociception is the central modulation of stimuli, due to surgical tissue damage, into behavioral, vegetative, and hormonal responses [5]. Currently there is no objective and absolute marks of nociception and pain [6] as well as «gold standard» for quantitive evaluation of nociception [7]. The specificity of somatic and vegetative reactions was insufficient to assess nociception, and the use of hemodynamic changes as markers of adequate pain relief resulted in excessive use of opioids [8]. Inappropriate administration of opioids contributes to increase of the frequency of their side effects such as nausea, vomiting, respiratory depression, opioid tolerance [9] and opioid-induced hyperalgesia, the latter being of paramount importance as it contributes to increased post-operative pain and may initiate mechanisms responsible for chronic pain [10]. Nociception monitoring is necessary to assess the balance between nociception caused by surgical trauma and anesthesia induced antinociception.
Monitoring and modulation of intraoperative nociception is a complex problem [11]. The choice of nociception assessment method mainly depends on the clinical context and the overall purpose of monitoring [12]. The methods for nociception assessing and the limitations of the methods are presented in Appendix.
There is a tendency to integrate nociception and analgesia balance indices into multimodal anesthetic monitors. For example, CARDEAN index (сardio-vascular depth of analgesia) was integrated into monitor Philips Intellivue®, HFVI index (high frequency variability index) — into monitor MDoloris Medical Systems. HFVI uses the same calculation algorithm as ANI index [13]. ANI index is calculated based on a high frequency component of heart rate variability (HRV) [14], modulated by the influence of respiratory frequency/rhythm, and displays instantaneous (ANIi) and 2-minute moving average (ANIm) value of ANI index. In case of nociception, sympathetic tone increases and parasympathetic tone decreases, which results in a decrease in АNI values (below 50) and hemodynamic reactivity [15].
Numerous studies indicated that variations in ANI index identify and reflect vegetative reactivity to nociceptive stimulation during anesthesia with non-inhaled [16] and inhaled anesthetics [17]. Some authors have evaluated the effectiveness of ANI Monitor in detecting nociceptive stimuli in patients with procedural sedation and analgesia (PSA) [18, 19]. The painfulness of catheter ablation of cardiac arrhythmias necessitates objective monitoring of intraoperative nociception, however, most nociception monitoring methods have limitations for patients with arrhythmias (Appendix). The development of technologies and, in particular, use of 3D-mapping of arrhythmogenic zones before catheter ablation made it possible to identify arrhythmogenic zones without inducing cardiac arrhythmias or with short-term induced arrhythmia, which allowed us to assume the possibility of effective use of ANI Monitor in this category of patients.
Objective
To evaluate the effectiveness of the monitoring system “ANI Monitor” for anesthesia and intensive care in patients with sinus rhythm and short-term induced (< 1 min) atrial arrhythmia (STIAA) during CA.
In the study the hypothesis that the use of ANI Monitor when performing anesthesia during CA will improve the detection of nociceptive stimuli and reduce the dose of opioid analgesics in patients with sinus rhythm and short-term induced (< 1 min) atrial arrhythmia (STIAA) was checked.
Materials and methods
A prospective observational study was conducted between April 2022 and May 2023 (Protocol No. 4 of the meeting of the local Ethics Committee of I.I. Mechnikov North-Western State Medical University dated April 6, 2022). The study included 188 patients with Class III according to the American Society of Anesthesiologists (ASA) [20]. Elective CA was performed in an X-ray surgical operating room for the treatment of patients with complex cardiac arrhythmias. During intervention all patients were monitored using a four-lead surface electrocardiogram and intracardiac electrograms, (CARTO® 3, Biosense Webster, Johnson & Johnson MedTech, USA), respiratory rates (RR), saturation (SpO2) and non-invasive blood pressure (NIBP), (GE B 30, General Electric Company, USA). At the time of the procedure all patients had a sinus rhythm. Then, atrial arrhythmia was provoked /induced, which was the reason for the intervention, for its mapping and subsequent treatment. The ablation index was taken into account when conducting CA in groups. The group consisted of 94 patients with sinus rhythm and STIAA during CA with monitoring of nociception/antinociception balance (ANI Monitor). The control group consisted of 94 patients selected by paired-linked selection (the “copy-pair” method according to the type of induced arrhythmia, kind and duration of intervention, gender and Charlson comorbid pathology index (Charlson Comorbidity Index, CCI). On the day of intervention antiarrhythmic therapy was performed with class II drugs (β-adrenoceptor blocking agents). ANI values were recorded at the following points: before femoral vein catheterization (FVC) (1); at the stage of FVC (2); after administration of fentanyl before CA (3); at the stage of CA (4); at the stage of hemostasis (5). At the stage of FVC using Seldinger's technique, RF ablation with lidocaine from 2.5 to 4.5 mg/kg was used under the control of an X-ray TV system. The sedation level during procedure varied from superficial to moderate (RASS −1/−2) and was achieved by intravenous fractional bolus administration of propofol. The dosage of fentanyl was carried out according to ANI (with a decrease in the index < 50). Hemodynamic parameters (Heart Rate (HR), Systolic Arterial Pressure (SAP), Diastolic Arterial Pressure (DAP)), Respiratory Rate, SрO2, pain assessment on a Numerical Rating Scale (NRS) (Table 1) were recorded at the same time points.
| Please rate the intensity of pain you are currently experiencing | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| No pain | Moderate pain | Very severe pain | ||||||||
Verbal contact was used to fix the pain assessment according to NRS in patients with RASS −1/−2 at the stage of CA (the question was short and repeated three times).
A NRS score of 3 points was adopted as the threshold for comparing ANI values, since NRS > 3 indicates the presence of moderate to severe pain and is used as a startpoint for therapeutic interventions. At the end of the intervention, a scale to assess satisfaction with anesthesiological support was used (Iowa Satisfaction with Anesthesia Scale [ISAS] in modification of E.V. Sinbukhova) [21] in the department routine practice since January 2020.
Inclusion criteria: 1) elective CA; 2) sinus rhythm; 3) III class according to the ASA classification; 4) patient consent; 5) patient age ˃18 or ˂ 75 years. Exclusion criteria: 1) patients with emergency interventions; 2) patients with chronic pain or autonomic nervous system disorders; 3) patients with CCI > 3 points; 4) patients with body mass index (BMI) ≥ 30 kg/m2; 5) patients with a pacemaker and/or administration of atropine.
Study flowchart is shown in Figure 1.
Fig. 1. Study flowchart BMI — Body Mass Index; CA — catheter ablation; CCI — Charlson Comorbidity Index; STIAA — Short-Term Induced Atrial Arrhythmia.
Statistical data processing was carried out using Statistica 10.0 and SPSS programs. Patients' characteristics and comparison in groups were carried out with an assessment of the compliance of the distributions of quantitative indicators with the normal law (Kolmogorov-Smirnov criterion). For quantitative variables which distribution differed from the normal value, the data were presented in the form of median and quartiles. In the comparative analysis of two independent groups Mann-Whitney criterion was used; when comparing indicators at the stages of surgical treatment Friedman variance analysis and Wilcoxon criterion were used. A 95 % confidence interval (95 % CI) was calculated. The structure of qualitative indicators was represented by the distribution of frequencies (%), the comparison of which in independent groups was performed by Pearson criterion c2. Correlation of quantitative indicators was assessed by means of a correlation coefficient. The assessment of the strength of the correlation coefficients was carried out on the Cheddock scale. The analysis was carried out using Spearman's rank correlation method. Differences in measured values were recognized as significant at the level of р < 0.05. To calculate ANI threshold values, classifying patients into 2-q groups according to NRS level (> 3 and ≤ 3) at the stages of FVC (Femoral Vein Catheterization) and ablation, ROC-analysis was performed with the construction of a characteristic curve (Receiver Operator Characteristic сurve). The diagnostic informativity of the method was assessed by determining the area under ROC-curve (AUC or Area Under Curve). The point on the ROC-curve maximizing the sum of sensitivity and specificity of classification was chosen as the optimal threshold value. The results of the diagnostic test with an area under the ROC-curve AUC equal to 0.8 were classified as good.
Results
The study and control groups were comparable in gender, CCI, ASA functional class, anesthetic support, type of surgery and its duration, heart rate before surgery and types of STIAA. Differences between the compared groups in age and body mass were revealed. The patients of the study group were older (age in the main group — 61.38 ± 11.35 years, in control group — 53.84 ± 15.10 years, p = 0.0005) and were overweight (BMI in the main group — 28.15 ± 4.94 kg/m², in control group — 25.35 ± 3.90 kg/m², р < 0.0001). The differences in ablation time in the study group were 52.36 ± 2.06 s, in control group — 50.87 ± 0.93 s, р < 0.0001. A comparison of the study and control groups is presented in Table 2.
| Parameter | Main group (n = 94) | Control group (n = 94) | p-value |
|---|---|---|---|
| Age, years | 61.38 ± 11.35 | 53.84 ± 15.10 | 0.0005* |
| Female, n (%) | 54 (57.40 %) | 57 (60.60 %) | 0.6564 |
| BMI, kg/m² | 28.15 ± 4.94 | 25.35 ± 3.90 | < 0.0001** |
| CCI, points | 2.11 ± 1.17 | 1.87 ± 1.06 | 0.2197 |
| Surgical intervention, n (%) | |||
| RF-isolation of the entries of the pulmonary veins | 70 (74.50 %) | 66 (70.20 %) | 0.3064 |
| RF-modification of AV-connection | 20 (21.30 %) | 23 (24.50 %) | |
| RFA ACP | 2 (2.10 %) | 0 (0 %) | |
| CA of cavo-tricuspid isthmus | 2 (2.10 %) | 5 (5.30 %) | |
| Heart rates at CA stage, n (%) | |||
| Sinus rhythm | 70 (74.50 %) | 58 (61.70 %) | 0.0081 |
| SVT | 23 (24.50 %) | 23 (24.50 %) | |
| AFL | 1 (1.10 %) | 5 (5.30 %) | |
| AF | 0 (0 %) | 8 (8.50 %) | |
| Ablation time, s | 52.36 ± 2.06 | 50.87 ± 0.93 | < 0.0001** |
| Surgery duration, min | 53.46 ± 17.67 | 50.95 ± 28.00 | 0.1528 |
| NRS > 3 with CA, n (%) | 25 (26.60 %) | 20 (21.30 %) | 0.3928 |
| Fentanyl dose, µg /kg/min | 0.04 ± 0.02 | 0.05 ± 0.03 | < 0.0001** |
| Propofol dose, mg/kg/min | 0.22 ± 0.06 | 0.27 ± 0.05 | 0.0609 |
| Health complications (total), % | 0 (0 %) | 3 (3.30 %) | 0.1551 |
| Satisfaction with Anesthesia Scale, points | 153.96 ± 3.00 | 152.30 ± 5.39 | 0.0494* |
ANI Monitor values were recorded during entire anesthetic support (Table 3).
| Stages | Number of measurements, M ± SD | Values, Ме (Q1–Q3) | NRS, M ± SD | ||
|---|---|---|---|---|---|
| ANIi | ANIm | ANIi | ANIm | ||
| Before FVC (background) | 5.5 ± 1.3 | 1.5 ± 0.7 | 75.00 (65.25–79.00) | 69.00 (60.00–76.00) | 0 |
| FVC | 11.0 ± 1.0 | 3.5 ± 0.7 | 69.50 (52.00–80.00) | 68.00 (59.00–79.00) | 0.6 ± 1.8 |
| After fentanyl before CA | 4.0 ± 1.0 | 1.0 ± 0.0 | 72.00 (61.00–82.00) | 67.00 (54.25–80.00) | 0 |
| CA | 53.0 ± 17.0 | 13.0 ± 3.0 | 70.00 (58.50–78.00) | 64.50 (58.00–76.00) | 1.5 ± 2.4 |
| Hemostasis | 12.5 ± 1.9 | 2.5 ± 0.7 | 72.00 (60.50–80.00) | 68.00 (60.00–80.00) | 0 |
At FVC stage during RF ablation, 22 (23.4 %) patients of the study group with sinus rhythm had pain syndrome with NRS ˃ 3, which was accompanied by a decrease of ANIi indicators. The revealed moderate negative correlation was statistically significant (r = −0.44; p < 0.0001). ANIi threshold value equal 51.0 divided patients with NRS ˃ 3 and NRS ≤ 3 with sensitivity 68.18 % and specificity 92.96 %. Area under ROC-curve AUC 0.78 (95 % CI 0.71–0.85; p < 0.001) for ANIi in patients at the stage of FVC with RA, which indicates good quality of information content of the predictive model. In parallel, ANIm indicators were recorded. Negative correlation between ANIm and NRS was statistically significant (r = −0.39; p < 0.0001). ANIm threshold value equal to 47.0 divided patients with NRS ˃ 3 and NRS ≤ 3 with sensitivity 54.55 % and specificity 100.00 %. Area under ROC-curve AUC 0.75 (95 % CI 0.68– 0.82; p < 0,001) for ANIm in patients at the stage of FVC with RA, which indicates good quality of information content of the predictive model. A retrospective analysis of the control group did not reveal any signs of pain syndrome in anesthesia and intervention protocols at the stage of FVC. At the stage of CA in patients of the study group, pain syndrome with NRS ˃ 3 was detected in 25 (26.60 %) patients, whereas in the control group — in 20 (21.30 %) patients respectively, p = 0.3928. When comparing hemodynamic reactivity within groups by NRS ≤ 3 and NRS > 3 the following changes were registered as shown in Table 4.
| Hemodynamic reactivity | NRS > 3 (n = 45) | NRS ≤ 3 (n = 143) | p-value |
|---|---|---|---|
| SBP, mm Hg | 126.51 ± 22.75 | 125.02 ± 14.39 | 0.6539 |
| DBP, mm Hg | 75.24 ± 9.68 | 75.55 ± 7.52 | 0.4746 |
| HR, bpm | 75.02 ± 14.42 | 71.08 ± 12.84 | 0.1701 |
| Main group (n = 94) | |||
| Hemodynamic reactivity | NRS > 3 (n = 25) | NRS ≤ 3(n = 69) | p-value |
| SBP, mm Hg | 134.00 ± 27.22 | 130.78 ± 18.21 | 0.8438 |
| DBP, mm Hg | 77.56 ± 11.38 | 75.49 ± 9.48 | 0.4652 |
| HR, bpm | 77.76 ± 17.69 | 68.81 ± 14.46 | 0.0175* |
| Control group (n = 94) | |||
| Hemodynamic reactivity | NRS > 3 (n = 20) | NRS ≤ 3 (n = 74) | p-value |
| SBP, mm Hg | 117.15 ± 9.84 | 119.65 ± 5.78 | 0.4919 |
| DBP, mm Hg | 72.35 ± 6.14 | 75.61 ± 5.15 | 0.0338* |
| HR, bpm | 71.60 ± 7.99 | 73.20 ± 10.80 | 0.4759 |
Differences in heart rate were registered in the study group between patients with NRS ˃ 3 and patients with NRS ≤ 3 (77.76 ± 17.69 and 68.81 ± 14.46 bpm respectively, р = 0.0175). An analysis of HR dynamics at the stages after administration of fentanyl before and during CA in the study group showed a decrease in HR from 80.72 ± 23.84 bpm to 77.76 ± 17.69 bpm which amounted to 3.62 %. Comparisons in the control group revealed differences in DBP between patients with NRS ˃ 3 and patients with NRS ≤ 3 (72.35 ± 6.14 и 75.61 ± 5.15 mm Hg respectively, р = 0.0338).
ANI difference was significant between patients with NRS ≤ 3 and NRS > 3. ANIi indicator in 69 (73.4 %) patients of the study group with NRS ≤ 3 amounted to 72.88 ± 10.11, whereas in 25 (26.6 %) patients with NRS > 3 amounted to 54.40 ± 16.09, respectively, р <0.0001. ANIm in 69 patients of the study group with NRS ≤ 3 amounted to 68.30 ± 11.39, whereas in 25 patients with NRS > 3 amounted to 60.64 ± 12.80, respectively, p = 0.0084. At CA stage in patients with sinus rhythm and STIAA under superficial/moderate sedation (RASS −1/−2) a statistically insignificant negative correlation was revealed between NRS and ANIi (r = −0.15; p = 0.1370). ANIi threshold value equal to 56.0 divided patients with NRS ˃ 3 and NRS ≤ 3 with sensitivity 48.00 % and specificity 88.41 %. Area under ROC-curve AUC 0.68 (95 % CI 0.64–0.71; p < 0.001) for ANIi in patients with sinus rhythm and STIAA at CA stage under moderate/superficial sedation, which indicates the average quality of information content of the predictive model.
Significant negative moderate correlation between the intensity of pain with NRS and ANI m (r = −0.37; p = 0.0003) revealed at the stage of ablation in the study group in 94 patients is shown in Figure 2.
Fig. 2.
Correlation
between NRS and ANIm at the CA stage (n = 94)
* Equal registered ANIm values
(points) are displayed as one.
NRS — The
Numerical Rating Scale.
ANIm threshold value equal to 56.0 divided patients with NRS ˃ 3 and NRS ≤ 3 with sensitivity 60.00 % and specificity 100.00 %. Area under ROC-curve AUC 0.81 (95 % CI 0.74 — 0.88; p < 0.001) for ANIm in patients with sinus rhythm and STIAA at the stage of CA under moderate/superficial sedation, which indicates a very good quality of information content of the predictive model.
The resulting Table 5 shows the thresholds and diagnostic information value of ANI in the detection of pain/nociception in patients at the stages of FVC and CA.
| Parameters | FVC stage | CA stage under PSA | ||
|---|---|---|---|---|
| ANIi | ANIm | ANIi | ANIm | |
| ANI threshold values | 51 | 47 | 56 | 56 |
| Area under curve ROC-curve AUC | 0.78 (0.71–0.85) | 0.75 (0.68–0.82) | 0.68 (0.64–0.71) | 0.81 (0.74–0.88) |
| Sensitivity, % | 68.18 | 54.55 | 48.00 | 60.00 |
| Specificity, % | 92.96 | 100.00 | 88.41 | 100.00 |
The total dose of fentanyl in the study group was 0.04 ± 0.02 µg/kg/min, whereas in the control group it was 0.05 ± 0.03 µg/kg/min, respectively, p < 0.001.
A comparison of the overall satisfaction of patients on Satisfaction with Anesthesia Scale in the study and control groups showed a statistically significant difference between investigated groups (see Table 1). Satisfaction with Anesthesia Scale score in patients of the study group was higher than in patients of the control group (153.96 ± 3.00 and 152.30 ± 5.39 respectively, р = 0.0494).
Discussion
Multimodal approaches aimed at maintaining an optimal balance of nociception and analgesia provide a reduction in postoperative nausea and vomiting, residual postoperative sedation and post-operative pain and are crucial for reducing the duration of hospitalization unrelated to the procedure [22]. The choice of using a particular monitoring mainly depends on the clinical context and the overall purpose of monitoring (Appendix).
ANI Monitor allows to identify nociceptive stimuli in conscious patients. In our study a negative moderate correlation between ANI and NRS was found, which meant lower ANI scores with higher NRS values (pain) at the stage of FVC in patients who are conscious under RA. Registration of ANI index at FVC stage under RF ablation showed the presence of pain syndrome with pain intensity according to NRS ˃ 3 in 22 (23.4 %) patients with sinus rhythm. A statistically significant moderate negative correlation was revealed (r = −0.44; p < 0.0001) between NRS and ANIi index as well as between NRS and ANIm (r = −0.39; p < 0.0001). With ANI threshold value 51 and 47 in patients with NRS > 3 with area under curve AUC 0.78 and 0.75, which indicates good information content of the predictive model. Similar data were obtained by Boselli et al. in investigation of 200 post-operative patients with ANI threshold values 57 and 48 to separate patients with NRS > 3 and > 7 with area under ROC-curve (AUC) 0.86 and 0.91 respectively [23]. However, the data obtained by the researchers vary. Baroni et al. defined correlation between ANI and Numerical Rating Scale (NRS) in patients, who are conscious, as weak [19].
Nociception monitors reflect physiological and pathophysiological responses to surgical stimuli, and therefore can be used to evaluate additional aspects of surgical stress responses [24]. Pain with NRS ˃ 3 at CA stage is registered in 25 (26.5 %) patients. Analysis of hemodynamic reactivity (HR, SBP, DBP) in case of pain in patients with NRS ≤ 3 and NRS > 3 during procedure did not show significant differences, whereas the difference in ANI indicators was significant. These results are consistent with previous studies and confirm the fact that hemodynamic variables are insufficient as a tool for detecting nociceptive stimuli. [25]. The group under investigation was characterized by the presence of STIAA during CA. That was ANIm or 2-minute moving average what made it possible to neutralize STIAA effects (˂ 1 min). Threshold value for ANIi and ANIm was identical and equal 56 in case of pain with NRS > 3 in patients at the stage of CA under PSA with RASS from −1 to −2, whereas specificity and sensitivity were different. Threshold value 56 for division of patients with NRS ≤ 3 and NRS > 3 at CA stage was obtained as for ANIi as for ANIm but good quality of the predictive model was achieved only for ANIm with AUC 0.81.
The issue of the effectiveness of using ANI index to control the administration of opioids is debatable. In our study titration of the dose of the opioid analgesic fentanyl under ANI control made it possible to significantly reduce opioid consumption in patients of the study group. A meta-analysis of six studies revealed no differences in intraoperative administration of opioids using analgesia under ANI control, whereas a gender analysis of subgroups showed the effectiveness of ANI for reducing opioid doses in female patients [26]. A meta-analysis by Ma et al. showed that intraoperative opioid administration was significantly lower in patients with NOL (Nociception Level index) and PPI (Pupillary Pain Index) monitoring than in patients with standard monitoring; however, no significant differences were found between patients with ANI and SPI (Surgical Pleth Index) control and patients with standard monitoring [25].
The key point of patient satisfaction with anesthesiological support was the absence of pain at all stages of surgery as well as nausea and vomiting and other negative consequences. Satisfaction with Anesthesia Scale Score in patients of the study group with ANI Monitor was higher.
Conclusion
ANI Monitor during CA in patients with sinus rhythm and STIAA was more effective in detecting harmful nociceptive stimuli compared to standard (hemodynamic) monitoring. The use of ANI Monitor to control the fentanyl administration could create conditions for opioid-sparing anesthesia.
Disclosure. The authors declare no competing interests.
Author contribution. All authors according to the ICMJE criteria participated in the development of the concept of the article, obtaining and analyzing factual data, writing and editing the text of the article, checking and approving the text of the article.
Ethics approval. This study was approved by the local Ethical Committee of North-Western State Medical University named after I.I. Mechnikov (reference number: 4-06.04.2022).
Funding source. This study was not supported by any external sources of funding.
Data Availability Statement. The data that support the findings of this study are available from the corresponding author upon reasonable request.
Appendix
| Monitoring of nociception | Measurement procedure | Threshold values of nociceptive stimulus for anesthesia | Limitations of the technique in accordance with the instruction of the manufacturer |
|---|---|---|---|
| Multichannel functional near-infrared spectroscopy system (fNIRS) (CW7, Tech En, Massachusetts, USA) | fNIRS wave length 690 and 830 nm and frequency 25 Hz Changes in hemoglobin oxygenation depending on cerebral activity | Nociceptive stimulus changes concentration ± 0,3 mM of oxygenated hemoglobin in certain brain regions (for example, somatosensorial and frontal polar cortex) | Movement artifacts Noise pollution Hemodynamic changes unrelated to brain activity The need for multiple optical sensors |
| Brain Anesthesia Response Monitor (BARM, Medtech Cortical Dynamics Ltd., Australia) | Electroencephalography | Index of cortical state (CS) and cortical input (CI) and its modifications | The level of nociception during
anesthesia is not defined Children’s age |
| Spectral Entropy Monitor (Module E-Entropy to patient’s monitors, GE Healthcare, Finland) | Electroencephalography Electromyography |
ΔSE-RE less than 10 | The level of nociception during
anesthesia is not defined Children’s age |
| Monitor for monitoring the depth of anesthesia and analgesia CONOX, QM 7000-M (Fresenius Kabi, Germany) | Electroencephalography Electromyography |
qNOX Index 61–99 — a patient prone to reacting to pain stimulation 40–60 — a patient is unlikely to respond to pain stimulation 0–39 — low probability of reaction to pain stimulation |
Blockers of neuromuscular
transmission Use as the only parameters for the dosage of an anesthetic A history of psychiatric, neurological diseases, drug and alcohol addiction Drugs administration affecting the central nervous system Defibrillation Children’s age |
| Nociceptive flexor reflex (NFR, Neurosoft, Russia) | Electromyography | > 31.9 mA weak nociceptive
stimulus (placing laryngeal mask) > 42.9 mA strong nociceptive stimulus (skin incision) |
Obesity Myopathies Blockers of neuromuscular transmission Children’s age |
| Pupillometry of analgesia (PRD/PPI IDMED, France) | Pupil size Pupillary light reflex and reflex pupil dilation Response to pain stimulation |
Amplitude of pupil dilation (PRD)
< 25 % (< 30 % in children) Pupillary pain index (PPI) > 7 |
Ptosis Heterotropia Anisocoria Aglia Afferent and efferent pupillary defects Neostigmine Droperidol Metoclopramide Clonidine Vasoactive drugs Cholinergic drugs Opioid analgesics (high doses) |
| The method of measuring skin conductivity (Med-Storm Innovations, AS, Norway) | Amplitude of fluctuations SC (ASCF) and number of fluctuations SC per second (NFSC) depending on the moisture percentage of the skin | A value of 0–0.07 corresponds to WBFS 0 (No pain), within 0.13–0.21 corresponds to WBFS 1–3 (Mild pain), 0.21–0.26 — WBFS 4–5 (Moderate pain), 0.26–0.33 — WBFS 6–8 (Severe pain) and 0.40–0.7 — WBFS 8–10 (Intense pain) | Skin temperature Ambient temperature Cholinergic and anticholinergic drugs Decreased sympathetic activity during deep anesthesia Children’s age |
| Surgical plethysmographic index (SPI, GE Healthcare, Finland) | SPI combines the normalized photoplethysmographic wave aplitude (PPGA) and normalized heart beat interval (HBI) into algorithm that displays the SPI values | SPI ˂ 20 — low
level of surgical stress ˃ 50 — high level of surgical stress |
Antiarrhythmics Cardiostimulator Chronotropic drugs Ephedrine Hypertension Poor signal and weak plethysmographic pulse Tachycardia Patient's position Severe hypothermia Cardiac arrhythmia Сan’t be used for other areas of the body except the finger Children’s age |
| Monitor PMD-200™ with NOL index (Medasense Biometrics Ltd., Israel) | Pulse rate, pulse rate variability
(0.15–0.4 Hz) Photoplethysmographic wave amplitude (PPGA) Number of fluctuations per second (NFSC) Accelerometer (movement) Peripheral temperature |
NOL index ˃ 25 may indicate a strong nociceptive reaction and the need for analgesia NOL between 0–25 assumes adequate analgesia NOL < 10 with surgical stimulation may indicate excessive analgesia |
Chronotropic drugs Vasoactive drugs Children’s age |
| Monitoring system «ANI Monitor» for anesthesiology, intensive care (Metrodoloris SAS, France) | High frequency range of HRV and respiratory arrhythmia | ANI index ˂ 50 high probability
of nociceptive stimulus ˃ 80 low probability of nociceptive stimulus |
Atrial fibrillation Cardiostimulator (some types) Heart transplantation (period of EC): Drugs affecting cardiac sinusoidal activity (atropine) Respiratory rate less than 9 cycles/min Asphyxia Variable respiratory volume during measurement, i.e. 64-х s) Interrupted respiration |
| CARDEAN Monitor (Alpha-2 Ltd, Lyon, France) | Heart rate Non-invasive blood pressure |
CARDEAN index > 60
somatosympathetic reflex and high probability of nociceptive stimulus ≤ 60 vagus nerve baroreflex and low probability of nociceptive stimulus |
Cardiac arrhythmia Inotropic drugs Chronotropic drugs Vasoactive drugs |
