Comparison of Surgical Pleth Index-guided Analgesia with Conventional Analgesia Practices in Children: A Randomized Controlled Trial

Analgesia nociception index is an indicator of laparoscopic trocar insertion-induced transient nociceptive stimuli

Objective

This study aimed to investigate whether analgesia nociception index (ANI) could be an indicator of perioperative pain during laparoscopic trocar insertion.

Methods

A total of 280 participants of anesthesia receiving laparoscopic surgery were enrolled. Anesthesia induction and maintenance were performed using the Marsh model for target propofol and the Minto model for remifentanil. Systolic blood pressure (SBP), heart rate (HR), and ANI were recorded at skin incision, the first-, second, the last-trocar insertion, and 5 min after the last trocar insertion.

Results

ANI was significantly different among the five groups in the last four time points (all P < 0.05). Pearson's correlation showed that ANI was negatively correlated with SBP (r = -0.114, P = 0.077) and HR (r = -0.247, P < 0.001). The area under the curve of ANI was positively correlated with those of SBP (r = 0.493, P < 0.001) and HR (r = -0.420, P < 0.001). Multivariate logistic regression showed that the ANI was an independent factor associated with intraoperative hemodynamic adverse events only at 5 min after the last trocar insertion.

Conclusions

Under general anesthesia, the change in ANI was consistent with changes in the balance between analgesia and nociceptive stimuli. The ANI can reflect the extent of transient pain but had a poor predictive performance for hemodynamic adverse events.

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.

Surgical pleth index monitoring in perioperative pain management: usefulness and limitations

Surgical pleth index (SPI) monitoring is a representative, objective nociception-monitoring device that measures nociception using photoplethysmographic signals. It is easy to apply to patients and the numerical calculation formula is intuitively easy to understand; therefore, its clinical interpretation is simple. Several studies have demonstrated its efficacy and utility. Compared with hemodynamic parameters, the SPI can detect the degree of nociception during surgery under general anesthesia with greater accuracy, and therefore can provide better guidance for the administration of various opioids, including remifentanil, fentanyl, and sufentanil. Indeed, SPI-guided analgesia is associated with lower intraoperative opioid consumption, faster patient recovery, and comparable or lower levels of postoperative pain and rates of adverse events compared with conventional analgesia. In addition, SPI monitoring allows for the degree of postoperative pain and analgesic requirements to be predicted through the SPI values immediately before patient arousal. However, because patient age, effective circulating volume, position, concomitant medication and anesthetic regimen and level of consciousness may be confounding factors in SPI monitoring, clinicians must be careful when interpreting SPI values. In addition, as SPI values can differ depending on anesthetic and analgesic regimens and the underlying disease, an awareness of the effects of these variables with an understanding of the advantages and disadvantages of SPI monitoring compared to other nociception monitoring devices is essential. Therefore, this review aimed to help clinicians perform optimal SPI-guided analgesia and to assist with the establishment of future research designs through clarifying current usefulness and limitations of SPI monitoring in perioperative pain management.

[New Approaches in Perioperative Algesimetry]

The measurement of anaesthetic depth and muscle relaxation have been routine procedures during general anaesthesia for years. Quantification of intraoperative nociception, on the other hand, is still largely impossible. Various methods have been tested and commercialised for more than 10 years. However, a real breakthrough has not yet been achieved and the routine application of all methods available so far is not without problems. This article explains methodological similarities, but also points to specific aspects of various commercial solutions for perioperative algesimetry.

Analgesia Nociception Index (ANI) as a monitor of peri-operative nociception-antinociception balance in paediatric craniotomies: a prospective observational study

INTRODUCTION

Analgesia Nociception Index (ANI) as a monitor of peri-operative nociception-anti-nociception balance has not been studied in paediatric neurosurgery. The objectives were to study the correlation between ANI (Mdoloris Education system) and revised FLACC (r-FLACC) score for the prediction of acute postoperative pain in paediatric population undergoing elective craniotomies and to compare the changes in ANI values with heart rate (HR), mean arterial pressure (MAP) and surgical plethysmographic index (SPI) during various time points of intraoperative noxious stimulation and before and after opioid administration.

METHODS

This prospective observational pilot study included 14 patients between 2 and 12 years of age undergoing elective craniotomies. HR, MAP, SPI, ANI instantaneous (ANIi) and ANI mean (ANIm) values were recorded intraoperatively and before and after opioid administration. Postoperatively HR, MAP, ANIi and ANIm, and pain scores (r-FLACC scale) were recorded.

RESULTS

There was a statistically significant negative correlation between ANIi and ANIm with r-FLACC during the time course of PACU stay (r =  - 0.89, p < 0.001 and r =  - 0.88 and p < 0.001 respectively). Intraoperatively, in patients with ANIi values < 50, with additional fentanyl administration, there was an increasing trend in values beyond 50, which was statistically significant (p < 0.05) at 3, 4, 5 and 10 min. The trend in changes of SPI after opioid administration was not found to be significant for patients irrespective of the baseline SPI values.

CONCLUSION

The ANI is a reliable tool for objective assessment of acute postoperative pain as assessed by r-FLACC in children undergoing craniotomies for intracranial lesions. It may be used as a guide to nociception-antinociception balance during the peri-operative period in this population.

Evaluation of the Averaged Parasympathetic Tone Activity and Its Dynamic Variation to Assess Intraoperative Nociception in Relation to Hemodynamic Changes in Dogs

This study aimed to determine the performance of the averaged parasympathetic tone activity (PTAm) and its dynamic variation (ΔPTA) to assess intraoperative nociception in relation to heart rate (HR) and direct mean arterial pressure (MAP) in dogs undergoing laparoscopic ovariectomy. This prospective, observational, clinical study included 32 bitches. The PTAm, HR, MAP, and bispectral index (BIS) were assessed before (pre-stimulus), as well as 1 min and 2 min after, four surgical stimuli: insufflation, introduction of trocars, and removal of the left and right ovaries. A two-way ANOVA was performed to compare PTAm, HR, MAP, and BIS data across surgical stimuli. A ≥20% drop in PTAm or a ≥20% increase in HR and/or MAP regarding the pre-stimulus values was considered a PTAm-drop and/or a hemodynamic response, respectively. The performance of PTAm pre-stimulus, PTAm 1 min, and ΔPTA in predicting the hemodynamic response was assessed by calculation of the area under the receiver operating characteristic (ROC) curve. At insufflation, PTAm decreased after 1 (p = 0.010) and 2 (p = 0.045)min, and ΔPTA was different (p = 0.005) between dogs that presented hemodynamic response and dogs that did not. At PTAm-drop, MAP increased after 1 min (p = 0.001) and 2 min (p = 0.001) with respect to pre-stimulus value, whereas HR and BIS did not change. ROC curves showed a threshold value of PTAm pre-stimulus ≤51 to detect hemodynamic response (sensitivity 69%, specificity 52%). The PTAm and ΔPTA only assessed intraoperative nociception during insufflation. The PTAm pre-stimulus association to the hemodynamic response in anaesthetized dogs showed poor sensitivity and no specificity.

Nociception level response to calibrated stimulations in children: First assessment of the nociception level index in pediatric anesthesia

INTRODUCTION

Intraoperative monitoring of nociception has made great progress in adult anesthesia. However, pediatric data are scarce. The Nociception Level (NOL) is one of the most recent indexes of nociception. Its originality is that it provides a multiparametric assessment of nociception. In adults, NOL monitoring allowed lower perioperative opioid requirements, hemodynamic stability, and qualitative postoperative analgesia. So far, the NOL has never been used in children. Our objective was to validate the ability of NOL to provide a quantitative assessment of nociception in anesthetized children.

METHODS

In 5-12 years old children anesthetized with sevoflurane and alfentanil (10 µg kg^-1), before surgical incision, we performed three standardized tetanic stimulations (5 s, 100 Hz) of different intensities (10-30-60 mA) in a randomized order. NOL, heart rate, blood pressure and Analgesia-Nociception Index variations were assessed after each stimulation.

RESULTS

Thirty children were included. Data were analyzed with a covariance pattern linear mixed regression model. NOL increased after the stimulations (p < 0.05 at each intensity). NOL response was influenced by stimulation intensity (p < 0.001). Heart rate and blood pressure were barely modified by the stimulations. Analgesia-Nociception Index decreased after the stimulations (p < 0.001 at each intensity). Analgesia-Nociception index response was not influenced by stimulation intensity (p = 0.064). NOL and Analgesia-Nociception Index responses were significantly correlated (Pearson r = 0.47; p < 0.001).

CONCLUSIONS

NOL allows a quantitative assessment of nociception under anesthesia in 5-12 years-old children. This study provides a solid basis for all future investigations on NOL monitoring in pediatric anesthesia.

REGISTRATION

NCT05233449.

Effect of surgical pleth index-guided remifentanil administration on perioperative outcomes in elderly patients: a prospective randomized controlled trial

BACKGROUND

During general anesthesia, the surgical pleth index (SPI) monitors nociception. The evidence of SPI in the elderly remains scarce. We aimed to investigate whether there is a difference in perioperative outcomes following intraoperative opioid administration according to the surgical pleth index (SPI) value versus hemodynamic parameters (heart rate or blood pressure) in elderly patients.

METHODS

Patients aged 65-90 years who underwent laparoscopic colorectal cancer surgery under sevoflurane/remifentanil anesthesia were randomized to receive remifentanil guided by SPI (SPI group) or conventional clinical judgment based on hemodynamic parameters (conventional group). The primary endpoint was intraoperative remifentanil consumption. Secondary endpoints were intraoperative hemodynamic instability, pain score, fentanyl consumption and delirium in the post-anesthesia care unit (PACU), and perioperative changes in interleukin-6 and natural killer (NK) cell activity.

RESULTS

Seventy-five patients (38, SPI; 37, conventional) were included in the study. The SPI group consumed significantly more remifentanil intraoperatively than the conventional group (mean ± SD, 0.13 ± 0.05 vs. 0.06 ± 0.04 μg/kg/min, P < 0.001). Intraoperative hypertension and tachycardia were more common in the conventional group than in the SPI group. Pain score in the PACU (P = 0.013) and the incidence of delirium in the PACU were significantly lower in the SPI group than the conventional group (5.2% vs. 24.3%, P = 0.02). There was no significant difference in NK cell activity and interleukin-6 level.

CONCLUSIONS

In the elderly patients, SPI-guided analgesia provided appropriate analgesia with sufficient intraoperative remifentanil consumption, lower incidence of hypertension/ tachycardia events, and a lower incidence of delirium in the PACU than the conventional analgesia. However, SPI-guided analgesia may not prevent perioperative immune system deterioration.

TRIAL REGISTRATION

The randomized controlled trial was retrospectively registered in the UMIN Clinical Trials Registry (trial number: UMIN000048351; date of registration: 12/07/2022).

Evaluation of Nociception during Pediatric Surgery: A Topical Review

The association between intraoperative nociception and increased patient's morbidity is well established. However, hemodynamic parameters, such as heart rate and blood pressure, may result in an inadequate monitor of nociception during surgery. Over the last two decades, different devices have been marketed to "reliably" detect intraoperative nociception. Since the direct measure of nociception is impractical during surgery, these monitors measures nociception surrogates such as sympathetic and parasympathetic nervous systems responses (heart rate variability, pupillometry, skin conductance), electroencephalographic changes, and muscular reflex arc. Each monitor carries its own advantages and disadvantages. The manuscript aims to give an overview of the most up-to-date information available in the literature on current nociceptor monitors available in clinical practice, with particular focus on their applications in pediatrics.

Elevated Surgical Pleth Index at the End of Surgery Is Associated with Postoperative Moderate-to-Severe Pain: A Systematic Review and Meta-Analysis

Despite acceptance of the surgical pleth index (SPI) for monitoring the intraoperative balance between noxious stimulation and anti-nociception under general anesthesia, its efficacy for predicting postoperative moderate-to-severe pain remains unclear. We searched electronic databases (e.g., Google Scholar, MEDLINE, Cochrane Library, and EMBASE) to identify articles focusing on associations of SPI at the end of surgery with immediate moderate-to-severe pain in the postanesthesia care unit from inception to 7 July 2022. A total of six observational studies involving 756 adults published between 2016 and 2020 were eligible for quantitative syntheses. Pooled results revealed higher values of SPI in patients with moderate-to-severe pain than those without (mean difference: 7.82, 95% CI: 3.69 to 11.95, p = 0.002, I2 = 46%). In addition, an elevated SPI at the end of surgery was able to predict moderate-to-severe pain with a sensitivity of 0.71 (95% confidence interval (CI): 0.65–0.77; I2 = 29.01%) and a specificity of 0.58 (95% CI: 0.39–0.74; I2 = 79.31%). The overall accuracy based on the summary receiver operating characteristic (sROC) curve was 0.72. In conclusion, this meta-analysis highlighted the feasibility of the surgical pleth index to predict postoperative moderate-to-severe pain immediately after surgery. Our results from a limited number of studies warrant further investigations for verification.

Nociception monitors vs. standard practice for titration of opioid administration in general anesthesia: A meta-analysis of randomized controlled trials

Background

Nociception monitors are being increasingly used during surgery, but their effectiveness in guiding intraoperative opioid administration is still uncertain. This meta-analysis of randomized controlled trials (RCTs) aimed to compare the effectiveness of nociception monitors vs. standard practice for opioid administration titration during general anesthesia.

Methods

We searched the electronic databases of PubMed, EMBASE, Cochrane Library, Clinical Trial, and Web of Science from inception up to August 1, 2021, to identify relevant articles, and extracted the relevant data. Intraoperative opioid administration, extubation time, postoperative pain score, postoperative opioid consumption and postoperative nausea and vomiting (PONV) were compared between patients receiving nociception monitoring guidance and patients receiving standard management. The standardized mean difference (SMD), with 95% confidence interval (CI), was used to assess the significance of differences. The risk ratio (RR), with 95% CI, was used to assess the difference in incidence of PONV. Heterogeneity among the included trials was evaluated by the I² test. RevMan 5.3 software was used for statistical analysis.

Results

A total of 21 RCTs (with 1957 patients) were included in the meta-analysis. Intraoperative opioid administration was significantly lower in patients receiving nociception monitor-guided analgesia than in patients receiving standard management (SMD, −0.71; 95% CI, −1.07 to −0.36; P < 0.001). However, pain scores and postoperative opioid consumption were not significantly higher in the former group. Considerable heterogeneity was found among the studies (92%). Extubation time was significantly shorter (SMD, −0.22; 95% CI, −0.41 to −0.03; P = 0.02) and the incidence of PONV significantly lower (RR, 0.78; 95% CI, 0.61 to 1.00; P = 0.05) in patients receiving nociception monitoring guidance.

Conclusions

Intraoperative nociception monitoring guidance may reduce intraoperative opioid administration and appears to be a viable strategy for intraoperative titration of opioids.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=273619, identifier: CRD42019129776.

Does surgical plethysmographic index-guided analgesia affect opioid requirement and extubation time? A systematic review and meta-analysis

Purpose

This meta-analysis of all relevant clinical trials investigated surgical plethysmographic index (SPI)-guided analgesia’s efficacy under general anesthesia for perioperative opioid requirement and emergence time after anesthesia.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched up to January 2022 to identify clinical trials comparing SPI-guided and conventional clinical practice for patients who underwent general anesthesia. With the random-effects model, we compared intraoperative opioid consumption, emergence time, postoperative pain, analgesia requirement, and incidence of postoperative nausea and vomiting (PONV).

Results

Thirteen randomized controlled trials (RCTs) (n = 1314) met our selection criteria. The overall pooled effect sizes of all RCTs indicated that SPI-guided analgesia could not significantly reduce opioid consumption during general anesthesia. SPI-guided analgesia accompanied with hypnosis monitoring could decrease intraoperative opioid consumption (standardized mean difference [SMD] − 0.31, 95% confidence interval [CI] − 0.63 to 0.00) more effectively than SPI without hypnosis monitoring (SMD 1.03, 95% CI 0.53–1.53), showing a significant difference (p < 0.001). SPI-guided analgesia could significantly shorten the emergence time, whether assessed by extubation time (SMD − 0.36, 95% CI − 0.70 to − 0.03, p < 0.05, I² = 67%) or eye-opening time (SMD − 0.40, 95% CI − 0.63 to − 0.18, p < 0.001, I² = 54%). SPI-guided analgesia did not affect the incidence of PONV, postoperative pain, and analgesia management.

Conclusion

SPI-guided analgesia under general anesthesia could enhance recovery after surgery without increasing the postoperative complication risk. However, it did not affect intraoperative opioid requirement. Notably, SPI-guided analgesia with hypnosis monitoring could effectively reduce intraoperative opioid requirement.

Comparison of the Newborn Infant Parasympathetic Evaluation (NIPE™) index to changes in heart rate to detect intraoperative nociceptive stimuli in healthy and critically ill children below 2 years: An observational study

BACKGROUND

The validity of current tools for intraoperative objective assessment of nociception/antinociception balance during anesthesia in young and very young surgery children is unknown.

AIM

Primary aim of the study was to test the hypothesis that the Newborn Infant Parasympathetic Evaluation (NIPE) index performs better in indicating nociception in anesthetized children below 2 years than changes in heart rate. Secondary aims were to evaluate associations between intraoperative changes in NIPE index values and postoperative pain and emergence delirium.

METHODS

Fifty-one children aged <2 years who underwent surgery were included in this prospective observational study. Patients were assigned to either group 1 (healthy children, n = 31) or group 2 (critically ill, ventilated premature infants and neonates, n = 20). The NIPE index and heart rate in response to three defined nociceptive stimuli were continuously recorded. Two different scales, Kindliche Unbehagens- und Schmerzskala (KUS) and Pediatric Anesthesia Emergence Delirium (PAED) as well as a Pain Questionnaire were used to assess postoperative pain levels and emergence delirium.

RESULTS

In total, 110 nociceptive events were evaluated. The analysis revealed a statistically significant association between a decrease in the NIPE index and all nociceptive stimuli, with a sensitivity of 92% and a specificity of 96%. The mean percentage decrease ranged from approx. 15%-30% and was highly statistically significant in both groups and for each of the nociceptive events except for venous puncture (p = .004). In contrast, no consistent change in heart rate was demonstrated. The KUS and PAED scale scores were significantly associated with the duration of anesthesia (p = .04), but not with intraoperative NIPE depression.

CONCLUSION

The NIPE index was reliable for assessing intraoperative nociception in children aged <2 years and was more reproducible for detecting specific nociceptive stimuli during general anesthesia than heart rate. An effect on postoperative outcome is still elusive.

Quantitative assessment of a pediatric nociception monitor in children under sevoflurane anesthesia

INTRODUCTION

Intraoperative monitoring of nociception has recently made substantial progress in adult anesthesia. In contrast, pediatric data are scarce. Newborn-Infant Parasympathetic Evaluation (NIPE index, Mdoloris Medical Systems, Loos, France) is the first nociception index specifically designed for young children. It is a dimensionless index comprised between 0 and 100. Two previous studies suggested that NIPE could indeed 'detect' nociception in anesthetized children. The objective of our study was to investigate if NIPE allowed to detect and to provide a quantitative assessment of nociception in children.

METHODS

Children were anesthetized with sevoflurane, and received a bolus of alfentanil (10 µg/kg before intubation). Before surgical incision, each participant received three tetanic stimulations (5 s, 100 Hertz) with a 5 min interval, in a randomized order: 10, 30 and 60 milliamps. NIPE and heart rate variations were assessed after each stimulation.

RESULTS

Thirty children (2.4±1.6 years) were included. Mean delay between alfentanil and the first stimulation was 19±4 min. Mean baseline NIPE was 75±10. NIPE variation after the stimulations was significant at 10, 30 and 60 mA (linear mixed regression model, p<0.001). The intensity of stimulation significantly influenced the amplitude of NIPE variation (linear mixed regression model p<0.001), but had no statistically significant effect on heart rate variation (p=0.52).

DISCUSSION

NIPE might allow a quantitative assessment of nociception in young children in these anesthetic conditions. This study provides a basis for future research investigating the potential benefits of NIPE-guided intraoperative analgesia in pediatric anesthesia.

TRIAL REGISTRATION NUMBER

NCT04381637.

Monitoring of analgesia level during general anesthesia in children

PURPOSE OF REVIEW

Monitoring of intraoperative nociception has made substantial progress in adult anesthesia during the last 10 years. Several monitors have been validated and their use has been associated with intraoperative or postoperative benefits in the adult population. In pediatric anesthesia, less data are available. However, several recent publications have assessed the performance of nociception monitors in children, and investigated their potential benefits in this context. This review will describe the main validated intraoperative nociception monitors, summarize adult findings and describe the available pediatric data.

RECENT FINDINGS

Six intraoperative nociception indices were included in this review. Among them, four have shown promising results in children: Surgical Pleth Index (GE-Healthcare, Helsinki, Finland), Analgesia-Nociception Index (Mdoloris Medical Systems, Loos, France), Newborn-Infant Parasympathetic Evaluation (Mdoloris Medical Systems), and Pupillometry (IDMED, Marseille, France). The relevance of Skin Conductance (MedStorm innovations, AS, Oslo, Norway) under general anesthesia could not be established. Finally, the Nociception Level (Medasense, Ramat Gan, Israel) still requires to be investigated in children.

SUMMARY

To date, four monitors may provide a relevant assessment of intraoperative nociception in children. However, the potential clinical benefits associated with their use to guide analgesia remain to be demonstrated.

Different perspectives for monitoring nociception during general anesthesia

Safe anesthesia is achieved using objective methods that estimate the patient’s state during different phases of surgery. A patient’s state under anesthesia is characterized by three major aspects, which are linked to the main effects produced by each of the families of anesthetic agents administered: hypnosis, analgesia, and muscular relaxation.

While quantification techniques designed to assess muscular relaxation under neuromuscular blocking agents have a relatively long history with a high degree of standardization and understanding (e.g., the train-of-four), the knowledge and techniques used to the depth of hypnosis assessment suffer from a lesser degree in both standardization and interpretation due to brain complexity.

The problem of standardization and interpretation in the analgesia and nociception assessment increases since it involves more systems, the central nervous system, and the autonomic nervous system.

This helps to explain why there are multiple a priori valid approaches to develop nociception monitoring from different interpretations and physiological bases of noxious stimuli processing. Thus, in this review, the current monitoring technologies clinically available for estimating a patient’s nociception under general anesthesia are described.

[Nociception monitoring : Method for intraoperative opioid control?]

The intraoperative dosing of opioids is a challenge in routine anesthesia as the potential effects of intraoperative overdosing and underdosing are not completely understood. In recent years an increasing number of monitors were approved, which were developed for the detection of intraoperative nociception and therefore should enable a better control of opioid titration. The nociception monitoring devices use either continuous hemodynamic, galvanic or thermal biosignals reflecting the balance between parasympathetic and sympathetic activity, measure the pupil dilatation reflex or the nociceptive flexor reflex as a reflexive response to application of standardized nociceptive stimulation. This review article presents the currently available nociception monitors. Most of these monitoring devices detect nociceptive stimulations with higher sensitivity and specificity than changes in heart rate, blood pressure or sedation depth monitoring devices. There are only few studies on the effect of opioid titration guided by nociception monitoring and the possible postoperative benefits of these devices. All nociception monitoring techniques are subject to specific limitations either due to perioperative confounders (e.g. hypovolemia) or special accompanying medical conditions (e.g. muscle relaxation). There is an ongoing discussion about the clinical relevance of nociceptive stimulation in general anesthesia and the effect on patient outcome. Initial results for individual monitor systems show a reduction in opioid consumption and in postoperative pain level. Nevertheless, current evidence does not enable the routine use of nociception monitoring devices to be recommended as a clear beneficial effect on long-term outcome has not yet been proven.

Effect of surgical pleth index-guided analgesia versus conventional analgesia techniques on fentanyl consumption under multimodal analgesia in laparoscopic cholecystectomy: a prospective, randomized and controlled study

BACKGROUND

The Surgical Pleth Index (SPI) is an objective tool that can reflect nociception-antinociception balance and guide the use of intraoperative analgesics. Multimodal analgesia has been neglected in many previous studies. The aim of this study was to compare fentanyl consumption using SPI-guided analgesia versus conventional analgesia techniques under multimodal analgesia in laparoscopic cholecystectomy.

METHODS

A total of 80 patients aged 18-65 years with American Society of Anaesthesiologists (ASA) grade I-II and a body mass index (BMI) of 18.5 to 30 kg/m2 who were scheduled for laparoscopic cholecystectomy under total intravenous anaesthesia from March 2020 to September 2020 were selected. Multimodal analgesia, including local infiltration of the surgical incision, nonsteroidal anti-inflammatory drugs and opioids, was adopted perioperatively. Fentanyl boluses of 1.0 µg/kg were administered to maintain the SPI value between 20 and 50 in the SPI group. By contrast, fentanyl boluses of 1.0 µg/kg were administered whenever the heart rate (HR) or mean arterial pressure (MAP) increased to 20 % above baseline or when the HR was greater than 90 beats per minute (bpm) in the control group. Preoperative and postoperative blood glucose, plasma cortisol and interleukin-6 (IL-6) levels were evaluated. Intraoperative haemodynamic events and propofol and fentanyl doses were noted. The extubation time, postoperative visual analogue scale (VAS) score, use of remedial analgesics and opioid-related adverse reactions were recorded.

RESULTS

In total, 18 of 80 patients withdrew for various reasons, and data from 62 patients were finally analysed. Intraoperative fentanyl consumption was significantly lower in the SPI group than in the control group (177.1 ± 65.9 vs. 213.5 ± 47.5, P = 0.016). The postoperative extubation time was shorter in the SPI group than in the control group (16.1 ± 5.2 vs. 22.1 ± 6.3, P < 0.001). Preoperative and postoperative blood glucose, plasma cortisol and IL-6 levels, intraoperative haemodynamic changes, postoperative VAS scores, remedial analgesic consumption and opioid-related adverse reactions were comparable in the two groups.

CONCLUSIONS

Lower doses of fentanyl are required intraoperatively with shorter extubation times when SPI is used to guide intraoperative analgesia compared to conventional analgesia techniques under multimodal analgesia in laparoscopic cholecystectomy.

TRIAL REGISTRATION

Chictr.org.cn ChiCTR2000030145 . Retrospectively Registered (Date of registration: February 24, 2020).

Comparison of adequacy of anaesthesia monitoring with standard clinical practice monitoring during routine general anaesthesia: An international, multicentre, single-blinded randomised controlled trial

BACKGROUND

Previous studies have suggested that monitoring the levels of both hypnosis and antinociception could reduce periods of inadequate anaesthesia. However, the evidence regarding associated benefits of this monitoring is still limited.

OBJECTIVE

The primary objective of this study was to confirm that guidance of anaesthesia by depth of hypnosis and antinociception monitoring decreases the number of inadequate anaesthesia events in comparison with standard clinical practice.

DESIGN

A multicentre, single-blinded, randomised controlled trial.

SETTING

The study was conducted in four European University hospitals in four different countries between December 2013 and November 2016.

PATIENTS

The study population consisted of a total of 494 adult patients undergoing elective surgery requiring tracheal intubation.

INTERVENTIONS

The patients were allocated to one of two groups. The first group was treated using Entropy for depth of hypnosis and surgical pleth index to determine depth of antinociception (adequacy of anaesthesia group; AoA group). The second group was monitored using standard monitoring alone (control group). Anaesthesia was conducted with target-controlled infusions of propofol and remifentanil.

MAIN OUTCOME MEASURES

The primary outcome of the study was the number of total unwanted events for example signs of inadequately light or unintentionally deep anaesthesia.

RESULTS

Evidence of inadequate anaesthesia had an incidence of around 0.7 events per patient in both groups with no difference between groups (P = 0.519). In the AoA group, the overall consumption of propofol was significantly reduced (6.9 vs. 7.5 mg kg h, P = 0.008) in comparison with the control group. The consumption of remifentanil was equal in both groups. The times to emergence [8.0 vs. 9.6 min (P = 0.005)] and full recovery in the postanaesthesia care unit (P = 0.043) were significantly shorter in the AoA group. No differences were seen in postoperative pain scores or in the use of analgesics.

CONCLUSION

In the current study, the guidance of total intravenous anaesthesia by Entropy and surgical pleth index in comparison with standard monitoring alone was not able to validate reduction of unwanted anaesthesia events. However, there was a reduction in the use of propofol, and shorter times for emergence and time spent in the postanaesthesia care unit.

TRIAL REGISTRATION

at ClinicalTrials.gov NCT01928875.

EEG-derived pain threshold index for prediction of postoperative pain in patients undergoing laparoscopic urological surgery: a comparison with surgical pleth index

Recently a novel pain recognition indicator derived from electroencephalogram(EEG) signals, pain threshold index(PTI) has been developed. The aim of this study was to determine whether PTI can be used for prediction of postoperative acute pain while surgical pleth index(SPI) applied as control. Eighty patients undergoing laparoscopic urological surgery under general anesthesia were enrolled. Data of SPI, PTI and a sedative index-wavelet index(WLI) were recorded within last 10 min at the end of surgery. The postoperative pain scores (NRS, numerical rating scale) were obtained. The Bland-Altman analysis was used for evaluation of consistency between PTI and SPI, whereas receiver-operating characteristic (ROC) curves was used for the mean values of PTI, SPI, and WLI to distinguish between mild (NRS 0-3) and moderate-severe (NRS 4-10) pain, and calculate their "best-fit" cut-off values. Data from 76 patients were included for final analysis. There was a good agreement between SPI and PTI values at the end of surgery. The ROC analysis showed a cut-off PTI value of 53 to discriminate between mild and moderate-to-severe pain, while SPI is 44 for this discrimination. Further analysis indicated that PTI had a best predictive accuracy reflected by highest area under curve (AUC)(0.772, 95% CI: 0.661-0.860)with sensitivity(62.50%) and specificity(90.91%) and a best positive predictive value(83.3%,95% CI: 68.4-98.2%). PTI obtained at the end of surgery, which have better predictive accuracy for postoperative pain than SPI, could differentiate the patients with moderate-to-severe pain from those with mild pain after they awaken from anesthesia.Clinical trial registration Chinese Clinical Trials Registry: ChiCTR1900024789.

Intraoperative nociception-antinociception monitors: A review from the veterinary perspective

OBJECTIVE

To review monitors currently available for the assessment of nociception-antinociception in veterinary medicine.

DATABASES USED

PubMed, Web of Science and Google Scholar. The results were initially filtered manually based on the title and the abstract.

CONCLUSIONS

The provision of adequate antinociception is difficult to achieve in veterinary anaesthesia. Currently, heart rate and arterial blood pressure are used to monitor the response to a noxious stimulus during anaesthesia, with minimum alveolar concentration-sparing effect and stress-related hormones used for this purpose in research studies. However, since none of these variables truly assess intraoperative nociception, several alternative monitoring devices have been developed for use in humans. These nociceptive-antinociceptive monitoring systems derive information from variables, such as electroencephalography, parasympathetic nervous system (PNS) response, sympathetic nervous system response and electromyography. Several of these monitoring systems have been investigated in veterinary medicine, although few have been used to assess intraoperative nociception in animals. There is controversy regarding their effectiveness and clinical use in animals. A nociceptive-antinociceptive monitoring system based on the PNS response has been developed for use in cats, dogs and horses. It uses the parasympathetic tone activity index, which is believed to detect inadequate intraoperative nociception-antinociception balance in veterinary anaesthesia. Nonetheless, there are limited published studies to date, and cardiovascular variables remain the gold standard. Consequently, further studies in this area are warranted.

Nociception monitoring tools using autonomic tone changes for intraoperative analgesic guidance in pediatric patients

Nociception monitoring devices using changes in autonomic nervous system activity have been developed in numerous ways. Although there have been few studies conducted on children, compared to the relatively higher number of studies on adults, most of the nociception monitors in children, as in adults, appear to be more useful than the standard clinical practice that uses hemodynamic parameters in the evaluation and treatment of intraoperative nociception (pain) during general anesthesia. Particularly, when monitoring the surgical pleth index (SPI) in anesthetized children, the application of a new target range of SPI values (≤ 40) to the SPI monitoring criteria seems to be necessary for providing a more proper intraoperative analgesia. The analgesia nociception index (ANI) shows promising results in anesthetized adults, and recently, positive results along with cardiorespiratory coherence have been reported in pediatric patients. Newborn infant parasympathetic evaluation (NIPE) could be useful for providing adequate analgesia in newborns, infants, and children under 2 years of age in anesthetized or awake states. In cases of skin conductance and pupillometry, further studies are needed. Understanding the pros, cons, and limitations of these nociception monitoring tools will provide more effective and safe intraoperative analgesia to pediatric patients undergoing general anesthesia, and it may also help to plan and conduct promising research on the use of perioperative nociception monitoring in pediatric patients in the future.

Nociception-guided versus Standard Care during Remifentanil-Propofol Anesthesia: A Randomized Controlled Trial

BACKGROUND

The multidimensional index of nociception, the nociception level, outperforms blood pressure and heart rate in detection of nociceptive events during anesthesia. We hypothesized that nociception level-guided analgesia reduces opioid consumption and suboptimal anesthesia events such as low blood pressure and use of vasoactive medication.

METHODS

In this single-blinded randomized study, 80 American Society of Anesthesiologists class I-III adult patients of either sex, scheduled for major abdominal procedures under remifentanil/propofol anesthesia by target-controlled infusion, were included. During the procedure nociception level, noninvasive blood pressure, and heart rate were monitored. Patients were randomized to receive standard clinical care or nociception level-guided analgesia. In the nociception level-guided group, remifentanil concentration was reduced when index values were less than 10 or increased when values were above 25 for at least 1 min, in steps of 0.5 to 1.0 ng/ml. Propofol was titrated to bispectral index values between 45 and 55. The primary outcomes of the study were remifentanil and propofol consumption and inadequate anesthesia events.

RESULTS

Compared with standard care, remifentanil administration was reduced in nociception level-guided patients from (mean ± SD) 0.119 ± 0.033 to 0.086 ± 0.032 μg · kg · min (mean difference, 0.039 μg · kg · min; 95% CI, 0.025-0.052 μg · kg · min; P < 0.001). Among nociception level-guided patients, 2 of 40 (5%) experienced a hypotensive event (mean arterial pressure values less than 55 mm Hg) versus 11 of 40 (28%) patients in the control group (relative risk, 0.271; 95% CI, 0.08-0.77; P = 0.006). In the nociception level-guided group, 16 of 40 (40%) patients received vasoactive medication versus 25 of 40 (63%) patients in the standard care group (relative risk, 0.64; 95% CI, 0.40-0.99; P = 0.044).

CONCLUSIONS

Nociception level-guided analgesia during major abdominal surgery resulted in 30% less remifentanil consumption.

Objective monitoring of nociception: a review of current commercial solutions

Nociception, in contrast to pain, is not a subjective feeling, but the physiological encoding and processing of nociceptive stimuli. However, monitoring nociception remains a challenge in attempts to lower the incidence of acute postoperative pain and the move towards a more automated approach to analgesia and anaesthesia. To date, several commercialised devices promise a more accurate reflection of nociception than the traditionally used vital signs, blood pressure and heart rate. This narrative review presents an overview of existing technologies and commercially available devices, and offers a perspective for future research. Although firm conclusions about individual methods may be premature, none currently appears to offer a sufficiently broad applicability. Furthermore, there is currently no firm evidence for any clinically relevant influence of such devices on patient outcome. However, the available monitors have significantly aided the understanding of underlying mechanisms and identification of potential pitfalls.

Surgical pleth index: prediction of postoperative pain in children?

Background

Surgical Pleth Index (SPI) is a non-invasive, dimensionless score (0-100) aimed to allow an estimate of intraoperative nociception. Thus, it may be a useful tool to guide intraoperative analgesia. However, no optimum SPI target range for the use in children has yet been defined. It was the aim of this study to define a clinically appropriate SPI target to predict moderate-severe postoperative pain in children.

Methods

After ethics approval 105 children (2-16 yr) undergoing elective sevoflurane/opioid-based anaesthesia were included. SPI was recorded directly before the end of surgery and compared with acute postoperative pain (age appropriately assessed on different pain scales in the age groups two to three yr, four to eight yr and nine to16 yr) in the postoperative acute care unit (PACU).

Results

Data of 93 children were analysed. A significant negative correlation was found between age and SPI (r=-0.43; P=0.03). The SPI cut-off value with the highest sensitivity (76%) and specificity (62%) in all children combined was 40. The negative predictive value for SPI ≤ 40 to predict the absence of moderate-severe pain in PACU was 87.5%. The commonly used SPI cut-off (50) published in all related studies had neither any clinically relevant sensitivity nor specificity to predict the presence or absence of acute pain in PACU.

Conclusions

The results suggest that a lower (≤ 40) than previously published (50) target for SPI may be more appropriate in studies investigating SPI guided anaesthesia in children, if the avoidance of moderate-severe postoperative pain is the main goal.

Clinical trial registration

ACTRN12616001139460.

Surgical pleth index: prospective validation of the score to predict moderate-to-severe postoperative pain

BACKGROUND

Reported outcome benefits after surgical pleth index (SPI, GE Healthcare, Helsinki, Finland) guided anaesthesia are conflicting. One potential explanation may be the lack of evidence for the selection of meaningful SPI target values. A recently published trial found an SPI cut-off of 30 as a 'best-fit' to predict moderate-to-severe acute postoperative pain. This prospective trial was designed to validate this target and to investigate the influence of patient age on SPI in this context.

METHODS

After ethics approval, 200 patients undergoing non-emergency surgery were enrolled. Data related to SPI, heart rate (HR), and mean arterial pressure (MAP) were recorded for the last 5 min of surgery, just before arousal. After admission to recovery, pain scores (numeric rating scale [NRS], 0-10) were obtained every 5 min for 15 min.

RESULTS

The data of 196 patients were analysed. Receiver-operating curve analysis showed a cut-off SPI value of 29 to be the optimum intraoperative target to discriminate between NRS 0-3 and 4-10. This confirms the 'best fit' cut-off for SPI published previously. Though still superior to HR and MAP, the sensitivity and specificity of the SPI were only poor. Age had no influence on the predictive accuracy of SPI.

CONCLUSIONS

An SPI of approximately 30 was confirmed as having the best sensitivity/specificity to predict moderate-to-severe pain in the postanaesthesia care unit. However, the predictive accuracy was overall poor and not influenced by patient age.

CLINICAL TRIAL REGISTRATION

ACTRN12617001475336.

Usefulness of surgical pleth index-guided analgesia during general anesthesia: a systematic review and meta-analysis of randomized controlled trials

Objective

Previous studies comparing surgical pleth index (SPI)-guided and conventional analgesia have shown differing results. Therefore, we compared the intraoperative opioid requirement, extubation time, postoperative pain scores, and perioperative adverse events between these two modalities.

Methods

A comprehensive literature search was conducted to identify randomized controlled trials comparing the intraoperative opioid requirement and other outcomes between the two modalities. The mean difference (MD) or the pooled risk ratio and corresponding 95% confidence interval (CI) were used for analysis. A heterogeneity (I²) assessment was performed.

Results

Six randomized controlled trials comparing 463 patients were included. Intraoperative opioid consumption was significantly lower in the SPI-guided than conventional analgesia group (standardized MD, −0.41; 95% CI, −0.70 to −0.11; I² = 53%). No significant intergroup difference was observed in the pain score on the first postoperative day or the incidence of perioperative adverse events. The extubation time was considerably shorter in the SPI-guided than conventional analgesia group (MD, −1.91; 95% CI, −3.33 to −0.49; I² = 67%).

Conclusions

Compared with conventional analgesia, SPI-guided analgesia can reduce intraoperative opioid consumption and facilitate extubation. Moreover, no intergroup difference was observed in the degree of postoperative pain or incidence of perioperative adverse events.

Surgical pleth index in children younger than 24 months of age: a randomized double-blinded trial

BACKGROUND

The surgical pleth index (SPI) is a measurement of intraoperative nociception. Evidence of its usability in children is limited. Given that the autonomic nervous system is still developing during the first years of life, the performance of the SPI on small children cannot be concluded from studies carried out in older age groups.

METHODS

Thirty children aged <2 yr, planned for elective open inguinal hernia repair or open correction of undescended testicle, were recruited. The children were randomized into two groups; the saline group received ultrasound-guided saline injection in the ilioinguinal and iliohypogastric nerve region before surgery and ropivacaine after surgery, whereas the block group received the injections in the opposite order. The SPI was recorded blinded and was analysed at the time points of intubation, incision, and when signs of inadequate anti-nociception were observed.

RESULTS

There was a significant increase in the SPI after intubation (P=0.019) and after incision in the saline group (P=0.048), but not at the time of surgical incision in the block group (P=0.177). An increase in the SPI was also seen at times of clinically apparent inadequate anti-nociception (P=0.008). The between-patient variability of the SPI was large.

CONCLUSIONS

The SPI is reactive in small children after intubation and after surgical stimuli, but the reactivity of the SPI is rather small, and there is marked inter-individual variability in reactions. The reactivity is blunted by the use of ilioinguinal and iliohypogastric nerve block.

CLINICAL TRIAL REGISTRATION

NCT02045810.

Surgical pleth index: prediction of postoperative pain and influence of arousal

BACKGROUND

There are conflicting reports concerning the outcome after anaesthesia guided by the surgical pleth index (SPI; GE Healthcare, Helsinki, Finland). One potential explanation may be the lack of evidence for the selection of SPI cut-off values. The aim of this trial was to investigate the correlation between SPI, arousal, and postoperative pain and to define a cut-off value for SPI to predict moderate-to-severe pain.

METHODS

After obtaining ethical approval and written informed consent, 70 patients undergoing non-emergency surgery were enrolled. Data relating to SPI, heart rate, mean arterial pressure, and state entropy were recorded every 10 s for the last 10 min of surgery (state entropy <60 at all times). Subsequently, recordings continued during the phase of arousal. After recovery room admission, pain scores (numerical rating scale 0-10) were obtained every 3 min for 15 min.

RESULTS

Data from 65 patients were analysed. Receiver-operating characteristic curve analysis revealed an optimal intraoperative cut-off SPI value of 30 to discriminate between numerical rating scale scores 0-3 and 4-10. For this value, the negative and positive predictive values to discriminate between numerical rating scale scores 0-3 and 4-10 were 50 and 89.7%, respectively. The SPI was significantly affected by arousal, and SPI scores obtained during this phase were not predictive of postoperative pain.

CONCLUSIONS

Surgical pleth index values are predictive of postoperative pain only if obtained before patient arousal. In contrast to previous studies, a relatively low SPI, >30, appears to predict pain with a high positive predictive value and may therefore be suggested for future studies of SPI-guided anaesthesia.

CLINICAL TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12615000804583.

Two different methods to assess sympathetic tone during general anesthesia lead to different findings

Noxious stimulation influences the autonomic nervous system activity. Sympathetic tone monitoring is currently used to assess the adequacy of the balance between nociception and anti-nociception during general anesthesia. The Surgical Plethysmographic Index (SPI) and the EBMi software (Custos©) are commercial devices that use different algorithms to measure it. We aimed at determining whether those devices provide similar information during routine surgical procedures under general anesthesia. Data acquired during a previously published study in patients undergoing surgery under general anesthesia were retrospectively analyzed and passed through the EBMi software. The occurrence of EBMi alarms of increased sympathetic tone was compared to the occurrence of SPI values ≥ 60, a commonly recommended intraoperative SPI threshold. Trends in classical parameters of sympathetic tone during the 5 min preceding a SPI ≥ 60, namely blood pressure, heart rate, and plethysmographic pulse amplitude were assessed. SPI ≥ 60 episodes (n = 307) were more frequent than EBMi alerts (n = 240). Approximately 70% of EBMi alerts occurred during periods where the SPI was below 60. Among all episodes of SPI ≥ 60, absence of any EBMi alerts was much more frequent than the inverse. A majority, but not all SPI ≥ 60 episodes were consistently preceded by an increase in heart rate and/or a decrease in pulse amplitude. Blood pressure did not significantly change before SPI ≥ 60. Longer SPI ≥ 60 episodes were associated with lower anti-nociception anesthetic regimen. Different methods of sympathetic tone assessment during general anesthesia provide conflicting information. Prospective studies should be undertaken to clarify the clinical indications of both techniques.

A single dose of dezocine suppresses emergence agitation in preschool children anesthetized with sevoflurane-remifentanil

Background

Emergence agitation (EA) is a common phenomenon in preschool children during emergence from general anesthesia. This study evaluated the safety and efficacy of dezocine for emergence agitation in preschool children anesthetized with sevoflurane-remifentanil.

Methods

A total of 100 preschool children, scheduled for elective laparoscopic repair of an inguinal hernia by high ligation of the hernia sac under sevoflurane-remifentanil anesthesia were randomized into two groups: Group C (n = 50) received Ringer’s lactate 10 mL and Group D received Ringer’s lactate 10 mL containing dezocine 0.1 mg/kg, postoperatively.

Results

Incidence of EA, defined as a score ≥ 3 on Aono’s four point scale or Pediatric Anesthesia Emergence Delirium (PAED) score ≥ 10 in the PACU (10% vs. 76%) and the percentage of patients with severe EA (PAED score ≥ 13) (12% vs. 76%) were significantly lower in Group D compared to Group C (P < 0.05). Mean Children and Infants Postoperative Pain Scale (CHIPPS) score was significantly lower in Group D compared to Group C (1.2 ± 0.5 vs. 5.2 ± 0.6; P < 0.05). Patients need for fentanyl (18% vs. 4%) or propofol rescue (20% vs. 0) was significantly greater in Group C compared to Group D. No significant differences in other relative aspects after surgery between groups.

Conclusion

Administration of dezocine 0.1 mg/kg decreased the incidence and severity of EA in preschool children that had undergone laparoscopic repair of an inguinal hernia by high ligation of the hernia sac under sevoflurane-remifentanil anesthesia.

Trial registration

A single dose of dezocine suppresses emergence agitation in preschool children anesthetized with sevoflurane-remifentanil effectively: A double-blind, prospective, randomized, controlled study, Chinese Clinical Trial Registry (ID: ChiCTR-IOR-16010033), retrospectively registered on November 21, 2016.

Implications of Entropy and Surgical Pleth Index-guided general anaesthesia on clinical outcomes in critically ill polytrauma patients. A prospective observational non-randomized single centre study

Being highly unstable, the critically ill polytrauma patient represents a challenge for the anaesthesia team. The aim of this study was to compare the Entropy and Surgical Pleth Index (SPI)-guided general anaesthesia with standard haemodynamic monitoring methods used in the critically ill polytrauma patients and to evaluate the incidence of hemodynamic events, as well as the opioid and vasopressor demand. 72 patients were included in this prospective observational study, divided in two groups, the ESPI Group (N = 37, patients that benefited from Entropy and SPI monitoring) and the STDR Group (N = 35 patients that benefited from standard hemodynamic monitoring). In the ESPI Group general anaesthesia was modulated in order to maintain the Entropy levels between 40 and 60. Analgesia control was achieved by maintaining the SPI levels between 20 and 50. In the STDR Group hypnosis and analgesia were maintained using the standard criteria based on hemodynamic changes. ClinicalTrials.gov identifier NCT03095430. The incidence of hypotension episodes was significantly lower in the ESPI Group (N = 3), compared to the STDR Group (N = 71) (p < 0.05). Moreover, the Fentanyl demand was significantly lower in the ESPI Group (p < 0.0001, difference between means 5.000 ± 0.038, 95% confidence interval 4.9250-5.0750), as well as vasopressor medication demand (p < 0.0001, difference between means 0.960 ± 0.063, 95% confidence interval 0.8.334-1.0866). The implementation of multimodal monitoring in the critically ill polytrauma patient brings substantial benefits both to the intraoperative clinical status and to the clinical outcome of these patients by reducing the incidence of anesthesia-related complications.

The effect of nicardipine on the surgical pleth index during thyroidectomy under general anesthesia: A prospective double-blind randomized controlled trial

BACKGROUND

The effectiveness of surgical pleth index (SPI) for managing nociception-antinociception balance during general anesthesia with vasodilators, including nicardipine has not been demonstrated. We aimed to compare the time course during surgery in SPI values in patients receiving nicardipine or remifentanil infusion during thyroidectomy.

METHODS

Forty patients undergoing thyroidectomy were randomly assigned to receive nicardipine (group N; n = 19) or remifentanil (group R; n = 21) along with induction (propofol, fentanyl, and rocuronium) and maintenance (50% desflurane/nitrous oxide in oxygen) anesthesia (goal bispectral index [BIS] ∼50). The infusion of nicardipine or remifentanil was started before the 1st incision and adjusted to keep mean blood pressure (MBP) within ±20% of the preoperative value. SPI, BIS, end-tidal desflurane concentration (EtDes), MBP, and heart rate were recorded at 2.5 minute intervals from the 1st incision to the end of surgery. Extubation and recovery times, pain score/rescue ketorolac consumption, and adverse events in postanesthesia care unit (PACU) were recorded.

RESULTS

The trend of SPI during surgery was comparable between the 2 groups (P = 0.804), although the heart rates in group N were significantly higher than those in group R (P = 0.040). The patient characteristics, trends of BIS, EtDes, and MBP during surgery, extubation and recovery times, and incidence of nausea/vomiting were comparable between the groups. Group N had significantly lower pain scores and rescue ketorolac consumption at PACU.

CONCLUSION

SPI was comparable between patients receiving nicardipine or remifentanil infusion during thyroidectomy under general anesthesia, which suggests that the administration of nicardipine may confound the interpretation of SPI values during general anesthesia.

CLINICAL TRIAL REGISTRATION

This trial was registered in the UMIN clinical trials registry (unique trial number: UMIN000019058; registration number: R000022028; principal investigator's name: Young Ju Won; date of registration: September 17, 2015).

"Safety and utility of percutaneous liver biopsy in hematopoietic stem cell transplant pediatric recipients: a retrospective study"

Background

Liver biopsies in pediatric hematopoietic stem cell transplantation (HSCT) patients are as and effective when performed at bedside in the Bone Marrow Transplant Unit (BMTU) than in the Day Surgery Unit (DSU), with better patient compliance and lower emotional distress for these children.

Methods

The study group consisted of 45 children who underwent allogeneic HSCT. We reviewed 68 liver biopsies performed between April 2006 and September 2015. 12 (17.6 %) biopsies were performed in the DSU and 56 (82.3 %) in the BMTU; nine (13.2 %) prior to HSCT and 59 (86.7 %) after HSCT. Pre-procedural behavioral status (subjective score) was evaluated by pediatric transplant physicians by filling in a questionnaire employing a three-point scale: “calm and cooperative”, “agitated and non-cooperative” or “frightened and suffering”. Objective score was obtained measuring patient’s heart rate before the procedure and comparing it with mean heart rate.

Results

Patients who underwent the procedure at the BMTU experienced less emotional distress than those who underwent it in the DSU: 58.3 % of patients treated at the DSU were agitated as compared with 16.1 % of those treated at the BMTU (p < 0.01). Among the 59 biopsies performed after HSCT, 41 (69.5 %) were taken from symptomatic patients for a diagnostic purpose and 18 (30.5 %) in asymptomatic ones in order to rule out hepatic GVHD. Among these 18 procedures, GVHD was diagnosed in 16 (88.9 %) cases. Minor complications occurred in about 17 % of procedures (12 biopsies), at a rate of 25 % for the DSU location compared with 16 % for the BMTU location. Only two major complications were reported, one in the DSU and one in the BMTU.

Conclusion

Liver biopsy performed at bedside in HSCT patients does not carry a higher risk of adverse events than the same procedure performed in the DSU and has lower emotional distress associated with better patient compliance, thus contributing significantly to a higher standard of care.

Comparison of relative oxycodone consumption in surgical pleth index-guided analgesia versus conventional analgesia during sevoflurane anesthesia: A randomized controlled trial

BACKGROUND

The surgical pleth index (SPI) is proposed for titration of analgesic drugs during general anesthesia. Several reports have investigated the effect of SPI on the consumption of opioids including remifentanil, fentanyl, and sufentanil during anesthesia, but there are no reports about oxycodone. We aimed to investigate intravenous oxycodone consumption between SPI-guided analgesia and conventional analgesia practices during sevoflurane anesthesia in patients undergoing thyroidectomy.

METHODS

Forty-five patients undergoing elective thyroidectomy were randomly assigned to an SPI group (SPI-guided analgesia group, n = 23) or a control group (conventional analgesia group, n = 22). Anesthesia was maintained with sevoflurane to achieve bispectral index values between 40 and 60. In the SPI group, oxycodone 1 mg was administered intravenously at SPI values over 50; in the control group, oxycodone 1 mg was administered intravenously at the occurrence of tachycardia or hypertension event. Intraoperative oxycodone consumption and extubation time were recorded. The number of hemodynamic and somatic movement events was recorded, as were postoperative pain and recovery scores.

RESULTS

Patients' characteristics were comparable between the groups. Intraoperative oxycodone consumption in the SPI group was significantly lower than the control group (3.5 ± 2.4 vs 5.1 ± 2.4 mg; P = 0.012). Extubation time was significantly shorter in the SPI group (10.6 ± 3.5 vs 13.4 ± 4.6 min; P = 0.026). Hemodynamic and somatic movement events during anesthesia were comparable between the groups, as were numeric rating scales for pain and modified Aldrete scores at postanesthesia care unit.

CONCLUSIONS

SPI-guided analgesia reduces intravenous oxycodone consumption and extubation time compared with conventional analgesia based on clinical parameters during sevoflurane anesthesia in patients undergoing thyroidectomy.