Analgesia Nociception Index Monitor Research Articles

Analgesia Nociception Index Monitor is an Objective Monitor for Predicting Successful Treatment after Epidural Blood Patch in a Spontaneous Intracranial Hypotension Patient - A Case Report

Headache induced by spontaneous intracranial hypotension (SIH) is a secondary headache syndrome. An epidural blood patch (EBP) serves as a treatment option when conservative measures fail. Analgesia nociceptive index (ANI) monitoring has been demonstrated to have advantages over standard clinical practice during general anesthesia and for detecting nociceptive stimulation during surgery. However, few studies have investigated ANI in postural headache patients. We presented a 38-year-old woman who experienced postural headache and was subsequently diagnosed with SIH. Despite her receiving conservative treatment, including hydration and analgesics, she continued to suffer from postural headaches. EBP was performed under ANI monitoring. Monitoring with the ANI revealed a rise in the mean ANI (ANIm) value from 44 to 93 during the EBP, which was correlated with headache relief. Two days post-EBP, the ANIm value reached 84. This case highlights the potential utility of ANI monitoring for objectively assessing SIH treatment outcomes and guiding therapeutic interventions.

Scalp Nerve Block for Enhanced Pain Control and Analgesic Optimization in Elective Craniotomy: A Randomized Controlled Trial with Analgesia Nociception Index Monitoring

In patients who are candidates for craniotomy, scalp nerve blocks have been shown to be effective in relieving pain intensity as well as postoperative hemodynamic stability after surgery, but the results have been inconsistent. We aimed to assess the effect of scalp block on pain control, intraoperative drug use under Analgesia Nociception Index (ANI) monitoring, and postoperative pain in patients who were candidates for elective craniotomy. In this randomized, single-blinded clinical trial study, candidates for craniotomy were randomly (using the block randomization method) divided into 2 groups before entering the operating room. The first group received a scalp block with bupivacaine (intervention), and the second group did not receive a scalp block (control) besides the routine anesthetic procedure in these patients. ANI, hemodynamic parameters, and the amounts of received remifentanil were conducted and compared. Patients under scalp block received less dosage of fentanyl than the nonscalp block group (mean=57.14±15.59 mcg vs. 250.00±65.04 mcg, respectively). Similarly, the dose of remifentanil required in the scalp block group was less (mean=3.04±1.95mg and 5.54±2.57mg, respectively). No difference was observed in hemodynamic parameters such as blood pressure and heart rate (before, during, and after surgery). However, the group receiving scalp block had higher ANI means than the control group. Scalp nerve block has an effective role in pain control (increasing ANI), consequently reducing the need for analgesic drugs such as fentanyl and remifentanil following craniotomy without changing the hemodynamic condition.

Predicting the optimal concentration of remifentanil for skull pin fixation with hemodynamic and analgesia nociception index monitoring

Inadequate antinociception during skull pin fixation may cause hemodynamic instability in intracranial surgery. The optimal concentration of remifentanil to provide adequate antinociception and stable hemodynamics during skull pin fixation under analgesia nociception index monitoring is unknown. This study is to assess the 90% effective concentration of remifentanil for skull pin fixation under hemodynamic and analgesia nociception index monitoring. Twenty-six patients were enrolled for intracranial surgery, anesthesia was induced and maintained under total intravenous anesthesia using target-controlled infusion for remifentanil and propofol under analgesia nociception index and bispectral index monitoring. Skull pin fixation was performed at different effect-site concentrations of remifentanil required for Dixon's up-and-down method with a step size of 0.5 ng/ml under bispectral index 40–60. Inadequate antinociception is defined when either ANI < 30 or > 20% in hemodynamic changes from baseline (e.g. heart rate > 100 beats/min, or blood pressure > 180/100 mmHg) and the effect-site concentration of remifentanil is considered as failure. It is considered success as ANI > 30 and < 20% hemodynamic changes from baseline simultaneously. Seven pairs of failure/success were used for probit analysis. The 90% effective concentration of remifentanil for skull pin fixation with adequate antinociception and hemodynamic stability was 4.7 ng/ml.

Is the heart rate variability monitoring using the analgesia nociception index a predictor of illness severity and mortality in critically ill patients with COVID-19? A pilot study.

IntroductionThe analysis of heart rate variability (HRV) has proven to be an important tool for the management of autonomous nerve system in both surgical and critically ill patients. We conducted this study to show the different spectral frequency and time domain parameters of HRV as a prospective predictor for critically ill patients, and in particular for COVID-19 patients who are on mechanical ventilation. The hypothesis is that most severely ill COVID-19 patients have a depletion of the sympathetic nervous system and a predominance of parasympathetic activity reflecting the remaining compensatory anti-inflammatory response.Materials and methodsA single-center, prospective, observational pilot study which included COVID-19 patients admitted to the Surgical Intensive Care Unit was conducted. The normalized high-frequency component (HFnu), i.e. ANIm, and the standard deviation of RR intervals (SDNN), i.e. Energy, were recorded using the analgesia nociception index monitor (ANI). To estimate the severity and mortality we used the SOFA score and the date of discharge or date of death.ResultsA total of fourteen patients were finally included in the study. ANIm were higher in the non-survivor group (p = 0.003) and were correlated with higher IL-6 levels (p = 0.020). Energy was inversely correlated with SOFA (p = 0.039) and fewer survival days (p = 0.046). A limit value at 80 of ANIm, predicted mortalities with a sensitivity of 100% and specificity of 85.7%. In the case of Energy, a limit value of 0.41 ms predicted mortality with all predictive values of 71.4%.ConclusionA low autonomic nervous system activity, i.e. low SDNN or Energy, and a predominance of the parasympathetic system, i.e. low HFnu or ANIm, due to the sympathetic depletion in COVID-19 patients are associated with a worse prognosis, higher mortality, and higher IL-6 levels.

Application of bispectral index and analgesia nociception index monitoring during laparoscopic cholecystectomy

The study provides a theoretical generalization and substantive solution to the scientific and practical problem of increasing the efficiency of anesthesia for surgical interventions, such as laparoscopic cholecystectomy, under individualized anesthetic support. This study also presents the peculiar courses of various anesthetic methods during the perioperative period in 120 patients with cholelithiasis who underwent laparoscopic cholecystectomy. Anesthesia types included total intravenous anesthesia using propofol and inhalation anesthesia with sevoflurane. Monitoring the bispectral index and analgesia and nociception index has been widely performed to assess the adequacy of various anesthetic options. These indices were also monitored to assess hemodynamic and autonomic regulation parameters in real time and to predict changes in these parameters intraoperatively. The results suggested the broad possibilities of monitoring, controlling, and minimizing the effect anesthesia on the cardiovascular system in conditions associated with a transient increase in the intra-abdominal pressure.

Effectiveness of the Analgesia Nociception Index Monitoring in Patients Who Undergo Colonoscopy with Sedo-Analgesia.

ObjectiveThe objective of this study was to improve the patient comfort and safety during procedures done under anaesthesia and sedation. The analgesia nociception index (ANI) noninvasively provides information on the nociception-antinociception balance, and it can be used to assess analgesia objectively. We aimed to compare the effects of analgesia management with conventional methods and with ANI monitoring on total opioid consumption, sedation and analgesia levels in patients who underwent colonoscopy using sedo-analgesia.MethodsAdult patients (n=102), scheduled for procedural sedation, were prospectively analysed. After the induction with propofol and ketamine, infusions of propofol (2 mg kg−1 h−1) and remifentanil (0.05 mcg kg−1 min−1) were started. In Group A, remifentanil infusions were titrated to maintain the ANI value between 50 and 70, whereas in Group C, analgesic requirements were met according to the attending anaesthetist’s intention. The heart rate, blood pressure, respiratory rate, SpO2, BIS, Numeric Rating Scale (NRS) and Ramsay Sedation Scale were monitored. Complications, analgesics consumption, duration of the procedure, demographic information, NRS and the Modified Aldrete Score were evaluated.ResultsA total remifentanil amount used in Group A was 66.51±47.87 mcg and 90.15±58.17 mcg in Group C (p=0.011); there was no difference in total amounts of ketamine and propofol given. There was a negative correlation between ANI and NRS scores of Group A patients at Minute 0 at the level of 0.402, which was significant statistically (p=0.003).ConclusionOpioid consumption was diminished when ANI monitoring was used, and thus the patient safety was improved. Further studies with longer procedure times and with a greater number of patients are required to demonstrate whether there is a difference in side effects and recovery times.

Effects of varying remifentanil concentrations on Analgesia Nociception Index® under propofol: an observational study.

Analgesia Nociception Index monitor provides a measurement of the nociception and anti-nociception balance based on heart-rate variability. The aim was to assess the ability of Analgesia Nociception Index (ANI) to detect standard noxious stimulation during anesthesia at different opioid concentrations in comparison to hemodynamic and Bispectral Index parameters. Sixteen patients undergoing general anesthesia with propofol and remifentanil. Standardized tetanic electrical stimulation was applied without any other concurrent stimuli, while different effect site concentrations of remifentanil were increased step-by-step (0.5, 1.5, 3.0, 5 and 7ng/ml). For each tetanic stimulus, values of the different variables 60s before and 120s following the stimulus were analyzed. ANI values decreased significantly 120s after the stimulus when compared to the mean ANI 60s before the stimulus (P < 0.01). At lower remifentanil concentrations (0.5ng/ml), all variables except electromyogram from the Bispectral Index significantly changed after the stimulus but in the higher concentrations (5.0 and 7.0ng/ml) there was not a significant change. The other variables did not change significantly after the noxious stimulation. ANI was the only variable that positively correlated with the different remifentanil concentrations (R = 0.959, P = 0.01). Our study showed that there was a significant decrease in Analgesia Nociception Index after a tetanic stimulation while hemodynamic and BIS parameters did not change, suggesting that the Analgesia Nociception Index may perform better than traditional hemodynamic parameters at reflecting noxious stimulation. Analgesia Nociception Index significantly changed at lower, but not at higher, remifentanil concentrations.

Should we include monitors to improve assessment of awareness and pain in unconscious palliatively sedated patients? A case report

Awareness and pain during palliative sedation is typically assessed by observational scales, but the use of such scales has been put into question. A woman in her mid-80s was admitted to a palliative care unit, presenting with chronic lymphatic leukemia, depression, and a cerebrovascular accident, with right-sided hemiplegia and aphasia. The patient was unable to eat and was suffering from nausea and vomiting. Before admission, the patient had expressed her desire to discontinue treatment on several occasions. The decision was made to initiate palliative sedation. The patient consented to take part in a study to assess level of comfort and pain using two monitoring devices (NeuroSense monitor and Analgesia Nociception Index monitor). The patient died 90 h after initiation of palliative sedation. Titration of the medication was challenging and sedation was not deep enough during the first 2 days. Thirteen assessments made with the Ramsay Sedation Scale showed that the patient was considered to be in a deep sleep, while in fact the NeuroSense monitor indicated otherwise. This case demonstrates the feasibility and potential advantages of using monitoring devices to objectify assessments of pain and discomfort in palliatively sedated patients.

Analgesia Nociception Index for perioperative analgesia monitoring in spinal surgery

The Analgesia Nociception Index is an index used to measure the levels of pain, sympathetic system activity and heart rate variability during general anesthesia. In our study, Analgesia Nociception Index monitoring in two groups who had undergone spinal stabilization surgery and were administered propofol-remifentanil (Total Intravenous Anesthesia) and sevoflurane-remifentanyl anesthesia was compared regarding its significance for prediction of postoperative early pain. BIS and Analgesia Nociception Index monitoring were conducted in the patients together with standard monitoring. During induction, fentanyl 2μg.kg-1, propofol 2.5mg.kg-1 and rocuronium 0.6mg.kg-1 were administered. During maintenance, 1.0 MAC sevoflurane+remifentanil 0.05-0.3μg.kg-1.min-1 and propofol 50-150μg.kg-1.min+remifentanil 0.05-0.3μg.kg-1.min-1 were administered in Group S and Group T, respectively. Hemodynamic parameters, BIS and Analgesia Nociception Index values were recorded during surgery and 30min postoperatively. Postoperative visual analog scale (VAS) values at 30minutes were recorded. While no difference was found between mean Analgesia Nociception Index at all times of measurement in both groups, Analgesia Nociception Index measurements after administration of perioperative analgesic drug were recorded to be significantly higher compared to baseline values in both groups. There was correlation between mean values of Analgesia Nociception Index and VAS after anesthesia. Analgesia Nociception Index is a valuable parameter for monitoring of perioperative and postoperative analgesia. In spine surgery, similar analgesia can be provided in both Total Intravenous Anesthesia with remifentanil and sevoflurane administration. Analgesia Nociception Index is efficient for prediction of the need for analgesia during the early postoperative period, and therefore is the provision of patient comfort.

Analgesia Nociception Index for perioperative analgesia monitoring in spinal surgery

Background and objectivesThe Analgesia Nociception Index is an index used to measure the levels of pain, sympathetic system activity and heart rate variability during general anesthesia. In our study, Analgesia Nociception Index monitoring in two groups who had undergone spinal stabilization surgery and were administered propofol–remifentanil (Total Intravenous Anesthesia) and sevoflurane–remifentanyl anesthesia was compared regarding its significance for prediction of postoperative early pain. MethodsBIS and Analgesia Nociception Index monitoring were conducted in the patients together with standard monitoring. During induction, fentanyl 2μg.kg−1, propofol 2.5mg.kg−1 and rocuronium 0.6mg.kg−1 were administered. During maintenance, 1.0 MAC sevoflurane+remifentanil 0.05–0.3μg.kg−1.min−1 and propofol 50–150μg.kg−1.min−1+remifentanil 0.05–0.3μg.kg−1.min−1 were administered in Group S and Group T, respectively. Hemodynamic parameters, BIS and Analgesia Nociception Index values were recorded during surgery and 30min postoperatively. Postoperative visual analog scale (VAS) values at 30minutes were recorded. ResultsWhile no difference was found between mean Analgesia Nociception Index at all times of measurement in both groups, Analgesia Nociception Index measurements after administration of perioperative analgesic drug were recorded to be significantly higher compared to baseline values in both groups. There was correlation between mean values of Analgesia Nociception Index and VAS after anesthesia. ConclusionAnalgesia Nociception Index is a valuable parameter for monitoring of perioperative and postoperative analgesia. In spine surgery, similar analgesia can be provided in both Total Intravenous Anesthesia with remifentanil and sevoflurane administration. Analgesia Nociception Index is efficient for prediction of the need for analgesia during the early postoperative period, and therefore is the provision of patient comfort.

The analgesia nociception index monitor (ANI) can detect indvertent vagal stimulation during surgery of cerebello-pontine angle tumors

The analgesia nociception index monitor (ANI) can detect indvertent vagal stimulation during surgery of cerebello-pontine angle tumors