Measurement of Heart Rate Variability to Assess Pain in Sedated Critically Ill Patients: A Prospective Observational Study

End-of-life Comfort Evaluation, is Clinic Enough? A Retrospective Cohort Study of Combined Comfort Evaluation with Analgesia/Nociception Index and Clinic in non-Communicative Patients

Background: Comfort evaluation is one of the major challenges in the palliative care setting, particularly when it comes to non-communicative patients. For this specific population, validated tools for comfort evaluation are scarce and healthcare professionals have to rely on their clinical sense and experience. Objectives: To provide arguments for the use of Analgesia/Nociception Index (ANI) monitoring in order to improve clinical comfort evaluation. Methods: We conducted a retrospective cohort study of non-communicative patients at the end of their lives whose comfort was evaluated clinically and with ANI. We focused on the coherence or discordance of clinical and ANI evaluations and on pharmacological interventions driven by them. Results: 58 evaluations from 33 patients were analyzed. Clinical and demographic characteristics were highly variable. Simultaneous clinical and ANI evaluations were concordant in 45 measurements (77.58%), leading mostly to no treatment modification when indicating comfort and to increasing anxiolytic or pain-relief treatments when indicating discomfort. Thirteen (22.41%) evaluations were discordant, leading mostly to treatment incrementation. Conclusion: We suggest that the ANI monitor is a reliable tool in the palliative setting and may help provide patients with the best symptom relief and the most appropriate therapeutics.

Pain Assessment and Management for a Chemically Paralyzed Child Receiving Mechanical Ventilation

BACKGROUND

Pain assessment in the pediatric intensive care unit (PICU) is complex, specifically for children receiving mechanical ventilation who require neuromuscular blockade (NMB). No valid pain assessment method exists for this population. Guidelines are limited to using physiologic variables; it remains unknown how nurses are assessing and managing pain for this population in practice.

OBJECTIVES

To describe how PICU nurses are assessing and managing pain for children who require NMB.

METHODS

A cross-sectional quantitative design was used with an electronic survey. Nurses were asked to respond to 4 written vignettes depicting a child who required NMB and had a painful procedure, physiologic cues, both, or neither.

RESULTS

A total of 107 PICU nurses answered the survey. Nurses primarily used behavioral assessment scales (61.0%) to assess the child's pain. All nurses reported that physiologic variables are either moderately or extremely important, and 27.3% of nurses used the phrase "assume pain present" formally at their organization. When physiologic cues were present, the odds of a nurse intervening with a pain intervention were 23.3 times (95% CI, 11.39-53.92; P < .001) higher than when such cues were absent.

CONCLUSIONS

These results demonstrate variation in how nurses assess pain for a child who requires NMB. The focus remains on behavioral assessment scales, which are not valid for this population. When intervening with a pain intervention, nurses relied on physiologic variables. Decision support tools to aid nurses in conducting an effective pain assessment and subsequent management need to be created.

The validity and applications of the analgesia nociception index: a narrative review

Pain refers to the subjective, unpleasant experience that is related to illness or injury. In contrast to pain, nociception refers to the physiological neural processing of noxious stimuli, such as intra-operative surgical stimuli. One novel device, the Analgesia Nociception Index (ANI), aims to objectively measure intra-operative nociception by analyzing the heart rate variability in patients undergoing surgery. Through this method of nociceptive monitoring, the ANI device aims to provide an objective, continuous evaluation of patient comfort levels and allow anesthesiologists to better manage surgical stress and patient analgesia, perhaps with even better efficacy than current practices used to assess nociception. Additionally, ANI may have clinical application in settings outside of the operating room, such as in the intensive care unit. In this narrative review, we compiled and summarized the findings of many studies that have investigated ANI's validity and applications in different clinical settings. Currently, the literature appears mostly supportive of ANI's ability to detect nociception in both surgical and non-surgical settings. However, the ability for ANI to provide clinical benefits, such as decreased intra-operative opioid use, post-operative opioid use, and post-operative pain compared to standard practices appear controversial. Because of the wide variety of methodology, clinical settings, patient populations, and limitations in these studies, more investigation of ANI is needed before any firm conclusions can be drawn on its clinical benefits.

Effects of man-made electromagnetic fields on heart rate variability parameters of general public: a systematic review and meta-analysis of experimental studies

OBJECTIVES

The effects of man-made electromagnetic fields (EMFs) on the cardiovascular system have been investigated in many studies. In this regard, the cardiac autonomic nervous system (ANS) activity due to EMFs exposure, assessed by heart rate variability (HRV), was targeted in some studies. The studies investigating the relationship between EMFs and HRV have yielded conflicting results. We performed a systematic review and meta-analysis to assess the data's consistency and identify the association between EMFs and HRV measures.

CONTENT

Published literature from four electronic databases, including Web of Science, PubMed, Scopus, Embase, and Cochrane, were retrieved and screened. Initially, 1601 articles were retrieved. After the screening, 15 original studies were eligible to be included in the meta-analysis. The studies evaluated the association between EMFs and SDNN (standard deviation of NN intervals), SDANN (Standard deviation of the average NN intervals for each 5 min segment of a 24 h HRV recording), and PNN50 (percentage of successive RR intervals that differ by more than 50 ms).

SUMMARY

There was a decrease in SDNN (ES=-0.227 [-0.389, -0.065], p=0.006), SDANN (ES=-0.526 [-1.001, -0.05], p=0.03) and PNN50 (ES=-0.287 [-0.549, -0.024]). However, there was no significant difference in LF (ES=0.061 (-0.267, 0.39), p=0.714) and HF (ES=-0.134 (0.581, 0.312), p=0.556). In addition, a significant difference was not observed in LF/HF (ES=0.079 (-0.191, 0.348), p=0.566).

OUTLOOK

Our meta-analysis suggests that exposure to the environmental artificial EMFs could significantly correlate with SDNN, SDANN, and PNN50 indices. Therefore, lifestyle modification is essential in using the devices that emit EMs, such as cell phones, to decrease some signs and symptoms due to EMFs' effect on HRV.

Evaluation of nociception in unconscious critically ill patients using a multimodal approach

This prospective observational study included 80 adults (>18 years) patients admitted to the intensive care unit who were unconscious (Glasgow Coma Scale [GCS] score <9 with a motor response <5) and receiving mechanical ventilation. A tetanic stimulation was used to assess nociception; automated pupillometry (Algiscan, ID-MED, France) was used to compute the pupillary pain index score (PPI), with a PPI > 4 considered as nociception. Concomitantly, the number of skin conductance fluctuations (NSCF) per second, measured using a Skin Conductance Algesimeter (SCA, MEDSTORM Innovation AS, Norway; > 0.27 fluctuations/sec indicating nociception), and the instantaneous Analgesia Nociception Index (iANI, MDoloris Medical Systems, France; <50 indicating nociception) were collected. Tetanic stimulation resulted in a median pupillary dilation of 16 [6-25]% and a PPI of 5 [2-7]. According to the PPI assessment, 44 patients (55%) had nociception, whereas 23 (29%) and 18 (23%) showed nociception according to the algesimeter and iANI assessment, respectively. No significant changes in measured physiologic variables were observed after the tetanic stimulation. There were no correlations between PPI, post-stimulation iANI, and SCA-derived variables. There were no differences in PPI, iANI, and SCA variables in patients with low and normal baseline EEG power at baseline. PERSPECTIVES: Detection of nociception varies across different devices in unconscious critically ill patients. Further studies are required to understand which method to implement for analgesic administration in this patient population.

Changes in Physiological Indices Before and After Nursing Care of Postoperative Patients With Esophageal Cancer in the ICU

Introduction

Various stressors have been identified in patients in the intensive care unit (ICU), including postoperative pain, ventilatory management, and nursing care. However, sedated patients are less responsive, and nurses have difficulty capturing their stressors.

Objective

To investigate patient stress caused by nursing care performed in the ICU on sedated patients based on changes in physiological indices.

Methods

We observed nursing care performed on patients with postoperative esophageal cancer under sedation in the ICU. This included endotracheal suctioning and turning, the time required for the care, and the patients' behavioral responses. Information on arousal levels, autonomic nervous system indices, and vital signs were also obtained. The changes in indicators before and after care were then compared and analyzed.

Results

There were 14 patients in the study. The mean age of the patients was 68 years. Ninety-nine scenes of nursing care were observed, and in six of these, additional bolus sedation was administered because of the patient's significant body movements. In endotracheal suctioning, no significant changes were observed in all indicators. In turning, vital signs changed significantly, and when both were continued, all indicators changed significantly.

Conclusion

Our study found that different types and combinations of nursing care may cause different stresses to the patients. Moreover, the autonomic nervous system indices may be more likely to react to stresses in a variety of nursing care, while arousal levels may be more likely to react to burdensome stresses. If the characteristics of these physiological indicators can be understood and effectively utilized during care, it may be possible to better identify and reduce patient stress during sedation management.

Prospective multicenter study of heart rate variability with ANI monitor as predictor of mortality in critically ill patients with COVID-19

The purpose of this study is to demonstrate that the most critically ill patients with COVID-19 have greater autonomic nervous system dysregulation and assessing the heart rate variability, allows us to predict severity and 30-day mortality. This was a multicentre, prospective, cohort study. Patients were divided into two groups depending on the 30-day mortality. The heart rate variability and more specifically the relative parasympathetic activity (ANIm), and the SDNN (Energy), were measured. To predict severity and mortality multivariate analyses of ANIm, Energy, SOFA score, and RASS scales were conducted. 112 patients were collected, the survival group (n = 55) and the deceased group (n = 57). The ANIm value was higher (p = 0.013) and the Energy was lower in the deceased group (p = 0.001); Higher Energy was correlated with higher survival days (p = 0.009), and a limit value of 0.31 s predicted mortalities with a sensitivity of 71.9% and a specificity of 74.5%. Autonomic nervous system and heart rate variability monitoring in critically ill patients with COVID-19 allows for predicting survival days and 30-day mortality through the Energy value. Those patients with greater severity and mortality showed higher sympathetic depletion with a predominance of relative parasympathetic activity.

Pain Assessment in Intensive Care Unit: A Forgotten Entity or a Quality Indicator?

How to cite this article: Havaldar AA. Pain Assessment in Intensive Care Unit: A Forgotten Entity or a Quality Indicator? Indian J Crit Care Med 2022;26(4):419–420.

Intelligent monitoring of noxious stimulation during anaesthesia based on heart rate variability analysis

Research based on medical signals has received significant attention in recent years. If the patients' states can be accurately monitored based on medical signals, it greatly benefits both doctors and patients. This paper proposes a method to extract signal features from heart rate variability signals and classify patients' states using the long short-term memory network and enable effective monitoring of noxious stimulation. For data processing, the heart rate variability signal is decomposed and recombined by the empirical mode decomposition method, and the signal features of the noxious stimulation are extracted by the sliding time window method. Compared with the average accuracy of direct classifications, the classification accuracy based on the proposed method is proved more accurate. The model based on the extracted features proposed can realize the classification of consciousness and general anaesthesia with an accuracy rate of more than 90% and accurately estimate the occurrence of tracheal intubation stimulation. Furthermore, this study shows that combining the deep learning neural network with the extracted more effective signal features under different states and stresses can classify the states with high accuracy. Therefore, it is promising to apply the deep learning method in researching the autonomic nervous system.

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In the context of end of life, palliative care offers support for the patient and his family, from a global perspective. This means paying attention to pain and difficult symptoms, but also to psychological, social and spiritual issues. Some situations confront healthcare teams with the difficulty of providing support to the end of life, not only in terms of relieving pain and suffering, but also when communication is impaired or even impossible. This is particularly the case with sedative practices. These situations involve providing comprehensive support by different evaluations of the patient&#8217;s pain and discomfort. This is therefore carried out by hetero-evaluation, by following observational pain assessment scales. Monitoring devices, such as ANI, usually used in anesthesia services, are experimented, for clinical purposes but also for research. In this article, we propose to analyze a clinical situation in which the use of ANI raised a whole series of questions about the use of the technical approach in palliative medicine and its integration into a care team. We will question some issues, in context, on the use of techniques and technologies in palliative medicine.

Early heart rate variability evaluation enables to predict ICU patients' outcome

Heart rate variability (HRV) is a mean to evaluate cardiac effects of autonomic nervous system activity, and a relation between HRV and outcome has been proposed in various types of patients. We attempted to evaluate the best determinants of such variation in survival prediction using a physiological data-warehousing program. Plethysmogram tracings (PPG) were recorded at 75 Hz from the standard monitoring system, for a 2 h period, during the 24 h following ICU admission. Physiological data recording was associated with metadata collection. HRV was derived from PPG in either the temporal and non-linear domains. 540 consecutive patients were recorded. A lower LF/HF, SD2/SD1 ratios and Shannon entropy values on admission were associated with a higher ICU mortality. SpO2/FiO2 ratio and HRV parameters (LF/HF and Shannon entropy) were independent correlated with mortality in the multivariate analysis. Machine-learning using neural network (kNN) enabled to determine a simple decision tree combining the three best determinants (SDNN, Shannon Entropy, SD2/SD1 ratio) of a composite outcome index. HRV measured on admission enables to predict outcome in the ICU or at Day-28, independently of the admission diagnosis, treatment and mechanical ventilation requirement.

Trial registration: ClinicalTrials.gov identifier NCT02893462.

Reliability of analgesia nociception index (ANI) and surgical pleth index (SPI) during episodes of bleeding – A pilot study

Background and Aims:

Methods:

Results:

Conclusion:

Newborn Infant Parasympathetic Evaluation Index for the Assessment of Procedural Pain in Nonanesthetized Infants: A Multicenter Pilot Study

OBJECTIVE

The aim of this study is to evaluate the ability of the Newborn Infant Parasympathetic Evaluation (NIPE) index to detect the response to nociceptive stimuli in nonanesthetized infants and to compare these results to simultaneous scoring by behavioral scales.

STUDY DESIGN

Thirty-six nonanesthetized infants admitted to neonatal/pediatric intensive care unit (N/PICUs) were enrolled to the study. Due to faulty records of the data, three patients had to be excluded. To detect pain caused by noxious stimuli, the heart-rate-variability-derived NIPE index and behavioral pain scales designed for measuring procedural pain in nonverbal children were used.

RESULTS

Forty-one painful events were available for analysis. We observed in the whole group a statistically significant decrease in NIPE values at 1, 2, and 3 minutes after a painful stimulus, in comparison to the NIPE value at rest and the statistically significant differences between the minimum NIPE value within 3 minutes after the stimulus in comparison to NIPE value at rest in the whole group, as well as in the subgroups of moderate and severe pain. Receiver operating characteristic (ROC) analysis has shown the strong sensitivity and specificity of the NIPE in detecting the noxious stimuli (ROC AUC: 0.767). We also found that the stronger the sensation of pain was, the more rapidly NIPE reached its lowest value.

DISCUSSION

Our study indicates that the painful procedures are associated with a significant decrease in the NIPE value within 3 minutes after a noxious stimulus. Based on our observation, the minimum value within 3 minutes from the painful procedure seems to be the most distinctive value.

A One-Day Prospective National Observational Study on Sedation-Analgesia of Patients with Brain Injury in French Intensive Care Units: The SEDA-BIP-ICU (Sedation-Analgesia in Brain Injury Patient in ICU) Study

BACKGROUND

Sedation/analgesia is a daily challenge faced by intensivists managing patients with brain injury (BI) in intensive care units (ICUs). The optimization of sedation in patients with BI presents particular challenges. A choice must be made between the potential benefit of a rapid clinical evaluation and the potential exacerbation of intracranial hypertension in patients with impaired cerebral compliance. In the ICU, a pragmatic approach to the use of sedation/analgesia, including the optimal titration, management of multiple drugs, and use of any type of brain monitor, is needed. Our research question was as follows: the aim of the study is to identify what is the current daily practice regarding sedation/analgesia in the management of patients with BI in the ICU in France?

METHODS

This study was composed of two parts. The first part was a descriptive survey of sedation practices and characteristics in 30 French ICUs and 27 academic hospitals specializing in care for patients with BI. This first step validates ICU participation in data collection regarding sedation-analgesia practices. The second part was a 1-day prospective cross-sectional snapshot of all characteristics and prescriptions of patients with BI.

RESULTS

On the study day, among the 246 patients with BI, 106 (43%) had a brain monitoring device and 74 patients (30%) were sedated. Thirty-nine of the sedated patients (53%) suffered from intracranial hypertension, 14 patients (19%) suffered from agitation and delirium, and 7 patients (9%) were sedated because of respiratory failure. Fourteen patients (19%) no longer had a formal indication for sedation. In 60% of the sedated patients, the sedatives were titrated by nurses based on sedation scales. The Richmond Agitation Sedation Scale was used in 80% of the patients, and the Behavioral Pain Scale was used in 92%. The common sedatives and opioids used were midazolam (58.1%), propofol (40.5%), and sufentanil (67.5%). The cerebral monitoring devices available in the participating ICUs were transcranial Doppler ultrasound (100%), intracranial and intraventricular pressure monitoring (93.3%), and brain tissue oxygenation (60%). Cerebral monitoring by one or more monitoring devices was performed in 62% of the sedated patients. This proportion increased to 74% in the subgroup of patients with intracranial hypertension, with multimodal cerebral monitoring in 43.6%. The doses of midazolam and sufentanil were lower in sedated patients managed based on a sedation/analgesia scale.

CONCLUSIONS

Midazolam and sufentanil are frequently used, often in combination, in French ICUs instead of alternative drugs. In our study, cerebral monitoring was performed in more than 60% of the sedated patients, although that proportion is still insufficient. Future efforts should stress the use of multiple monitoring modes and adherence to the indications for sedation to improve care of patients with BI. Our study suggests that the use of sedation and analgesia scales by nurses involved in the management of patients with BI could decrease the dosages of midazolam and sufentanil administered. Updated guidelines are needed for the management of sedation/analgesia in patients with BI.

Influence of Sliding Time Window Size Selection Based on Heart Rate Variability Signal Analysis on Intelligent Monitoring of Noxious Stimulation under Anesthesia

In recent decades, little progress of objective evaluation of pain and noxious stimulation has been achieved under anesthesia. Some researches based on medical signals have failed to provide a general understanding of this problem. This paper presents a feature extraction method for heart rate variability signals, aiming at further improving the evaluation of noxious stimulation. In the process of data processing, the empirical mode decomposition is used to decompose and recombine heart rate variability signals, and the sliding time window approach is used to extract the signal features of noxious stimulation, respectively. The influence of window size on feature extraction is studied by changing the window size. By comparing the results, the feature extraction in the process of data processing is valuable, and the selection of window size has a significant impact. With the increase of selected window sizes, we can get better detection results. But for the best choice of window size, to ensure the accuracy of the results and to make it easy to use, then, we need to get just a suitable window size.

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

Introduction

The 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 methods

A 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.

Results

A 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%.

Conclusion

A 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.

Evaluation of Nociception Using Quantitative Pupillometry and Skin Conductance in Critically Ill Unconscious Patients: A Pilot Study

Background: Pain assessment is a challenge in critically ill patients, in particular those who are unable to express movements in reaction to noxious stimuli. The purpose of the study was to compare the pupillary response and skin conductance to pain stimulation in critically ill unconscious patients. Methods: This observational study included adult patients admitted to the intensive care unit (ICU) with acute brain injury (Glasgow Coma Scale < 9 with a motor response < 5) and/or requirements for deep level of sedation. Automated pupillometry (Algiscan, ID-MED, Marseille, France) was used to determine pupillary reflex dilation during tetanic stimulation. The maximum intensity of the stimulation value allowed the determination of a pupillary pain index score ranging from 1 (no nociception) to 9 (high nociception): a pupillary pain index (PPI) score of ≤4 was used to reflect adequate pain control. For skin conductance (SC), the number of SC peaks per second (NSCF) was collected concomitantly to tetanic stimulation. An NSCF of ≤0.07 peak/second was used to reflect adequate pain control. Results: Of the 51 included patients, there were 32 with brain injury and 19 receiving deep sedation. Mean PPI score was 5 (Interquartile Range= 2–7); a total of 28 (55%) patients showed inadequate control of the nociceptive stimulation according to the PPI assessment. Only 15 (29%) patients showed a detectable skin conductance, with NSCF values from 0.07 to 0.47/s. No correlation was found between skin conductance algesimeter (SCA)-derived variables and PPI score or pupillary dilation to pain. Conclusions: Detection of inadequate pain control might vary according to the method used to assess nociception in ICU patients. A poor agreement between quantitative pupillometry and skin conductance was observed.

Newborn infant parasympathetic evaluation for the assessment of analgosedation adequacy in infants treated by mechanical ventilation - a multicenter pilot study

INTRODUCTION

Adequate analgosedation is important in infants treated in pediatric/neonatal intensive care units (P/NICUs), because both too deep and insufficient analgosedation is disadvantageous. To assess the severity of pain, several behavioral and behavioral-physiological scales are used, but their usefulness is limited. It is therefore justified to search for additional methods to assess the adequacy of analgosedation in these patients. The aim of the present study is to evaluate the usefulness of Newborn Infant Parasympathetic Evaluation (NIPE) in the assessment of analgosedation quality in infants requiring mechanical ventilation, who are treated in P/NICUs.

MATERIAL AND METHODS

We performed simultaneously 180 COMFORT-B assessments and heart rate variability measurements using a NIPE monitor in 30 mechanically ventilated infants receiving analgosedation. A generalized linear mixed model with the logit link function was used in order to perform logistic regression analysis to assess the relationship between NIPEi/NIPEm and deep sedation.

RESULTS

The multivariable logistic regression model showed that NIPEi and NIPEm values were higher when analgosedation was deep as compared to when it was moderate or insufficient (OR (95% CI): NIPEm - 1.065 (1.007-1.126), p = 0.03; NIPEi - 1.068 (1.016-1.123), p = 0.01).

CONCLUSIONS

The NIPE indexes are significantly higher in patients whose assessment on the behavioral scale indicates deep analgosedation as compared to those in whom it indicates moderate or insufficient analgosedation. Allowing continuous monitoring, the NIPE device may be a valuable assisting tool in the assessment of analgosedation quality in mechanically ventilated newborns and infants.

Adjuvant lidocaine to a propofol-ketamine-based sedation regimen for bone marrow aspirates and biopsy in the pediatric population

Pediatric patients with hematological malignancies repeatedly undergo painful bone marrow aspirates and biopsies (BMABs) in routine care. No standard sedation regimen has been established. This study evaluated the addition of injected local lidocaine to a propofol-ketamine sedation for BMAB and its effects on propofol dosing, safety, and efficacy. A retrospective analysis of children undergoing BMAB with propofol-ketamine with (PK+L) and without (PK-only) the injection of local lidocaine. Patients were matched through propensity probability scores. To measure efficacy, dosing, procedure length, and recovery time were evaluated. To assess safety, adverse and serious events were recorded. As an indirect measurement of analgesia, changes in heart rate and blood pressure were analyzed. Of the 420 encounters included, 188 matched pairs (376 patients) were analyzed. Patient demographics were comparable. The median dose of propofol was not significantly different between both groups. The incidence of adverse events was similar. There were no significant differences in the changes in heart rate and blood pressure with sedation between groups.Conclusion: This study suggests that the addition of local lidocaine injection to a propofol-ketamine sedation for BMAB pediatric patients does not affect the propofol dose, safety, or efficacy properties of the regimen. What is Known: •Although propofol is commonly used, there is no standard sedation regimen for pediatric patients undergoing bone marrow aspiration and biopsy. •Local lidocaine is used in analgesia in the adults undergoing the same procedure. What is New: •Local lidocaine adjuvant to propofol-ketamine sedation does not affect propofol dosing, the safety of efficacy properties of the regimen in the pediatric population.

Assessment of Procedural Distress in Sedated/Intubated Children Under 3 Years Old Using the Newborn Infant Parasympathetic Evaluation: A Diagnostic Accuracy Pilot Study

OBJECTIVES

Newborn infant parasympathetic evaluation index is based on heart rate variability and is related to the autonomic response to pain or stress. The Comfort Behavior Scale is used to assess distress intensity in sedated intubated children. The objective of this study was to assess the validity and performance of newborn infant parasympathetic evaluation as a distress indicator during procedural distress.

DESIGN

Monocentric, prospective, noninterventional pilot study of diagnostic accuracy between October 1, 2017, and April 30, 2019.

SETTING

PICU in a tertiary care university hospital.

PATIENTS

Sedated intubated children under 3 years old.

INTERVENTIONS

We continuously obtained mean newborn infant parasympathetic evaluation and instantaneous newborn infant parasympathetic evaluation scores and compared them to Comfort Behavior scores obtained before (T1 period), during (T2 period), and after (T3 period) care procedures.

MEASUREMENTS AND MAIN RESULTS

We obtained 54 measurements from 32 patients. The median age was 4 months (23 d to 31 mo). Between T1 and T2, there was a significant decrease in the instantaneous newborn infant parasympathetic evaluation and mean newborn infant parasympathetic evaluation scores (64 ± 2 to 42 ± 1 [p 0.0001] and 64 ± 1 to 59 ± 1 [p = 0.007], respectively) and a significant increase in the Comfort Behavior scores (from 12 ± 0 to 16 ± 1; p 0.0001). Comfort Behavior scores and instantaneous newborn infant parasympathetic evaluation and mean newborn infant parasympathetic evaluation scores were significantly inversely correlated (r = -0.44, p 0.0001 and r = -0.19, p = 0.01, respectively). With a instantaneous newborn infant parasympathetic evaluation score threshold of 53, the sensitivity, specificity, positive predictive, and negative predictive values to predict a Comfort Behavior Scale up to 17 were 80.0%, 73.5%, 43.8%, and 93.5%, respectively.

CONCLUSIONS

Instantaneous newborn infant parasympathetic evaluation is valid for assessing distress in sedated/intubated children in the PICU. Further studies are needed to confirm these results and for newborn infant parasympathetic evaluation-based comparisons of sedation-analgesia protocols.

ANI and BIS variations in supine and prone position during closed-tracheal suction in sedated and myorelaxed ICU patients with severe COVID-19: A retrospective study

The purpose of this study was to assess Analgesia/Nociception Index (ANI) and bispectral index (BIS) variations in supine and prone position during closed-tracheal suction in intensive care unit (ICU) patients with severe COVID-19 pneumonia requiring myorelaxation and prone positioning. We retrospectively reviewed the data of 15 patients hospitalized in ICU for severe COVID-19 pneumonia requiring sedation, myorelaxation and prone positioning. The BIS, instant ANI (ANIi), mean ANI (ANIm), heart rate (HR), systolic blood pressure (SBP) and SpO₂ were retrieved in supine and prone position 1 min before tracheal suction then every minute from the beginning of tracheal suction during 4 min and compared using ANOVA for repeated measures (p < 0.05 considered as statistically significant). Both ANIm and ANIi decreased significantly during tracheal suction with no difference between positions, whereas BIS showed no significant variation within time and between groups. The median [Q1–Q3] ANIm value decreased from 87 [68–98] to 79 [63–09] in supine position and from 79 [63–95] to 78 [66–98] in prone position 2 min after the beginning of tracheal suction. The median [Q1–Q3] ANIi value decreased earlier 1 min after the beginning of tracheal suction from 84 [69–98] to 73 [60–90] in supine position and from 84 [60–99] to 71 [51–88] in prone position. Both HR, SBP and SpO₂ varied modestly but significantly during tracheal suction with no difference between positions. Monitoring ANI, but not BIS, may be of interest to detect noxious stimuli such as tracheal suction in ICU myorelaxed patients with severe COVID-19 pneumonia requiring prone positioning.

Neurophysiological Assessments During Continuous Sedation Until Death Put Validity of Observational Assessments Into Question: A Prospective Observational Study

Introduction

In case of untreatable suffering at the end of life, continuous sedation until death (CSD) may be the only treatment option left. Because these patients cannot communicate anymore, caregivers have to rely on behavioral observation to assess the patient’s comfort. Recently, however, a number of studies from the neurosciences have shown that sometimes consciousness and pain are undetectable with these traditional behavioral methods. The aim of this study was to find out if subjective caregiver assessments of consciousness and pain would be confirmed by objective neurophysiological measures.

Methods

In this prospective observational study, we observed patients from the start of palliative sedation until death. Subjective caregiver assessments of level of consciousness and pain based on behavioral observations were compared with objective measures from neurophysiological monitoring devices.

Results

We collected and analyzed 108 subjective caregiver assessments in a sample of 12 patients and 32 assessments by traditionally used observational scales. We compared these with objective neurophysiological measures. Sensitivity and specificity of caregivers’ subjective assessments of consciousness was 23.6 and 91.1% respectively, with an accuracy of 54.0% and interrater reliability (κ) of 0.13. For pain, this was 0 and 94.79%, respectively, an accuracy of 88%, and an inter-rater reliability (κ) of − 0.063. Agreement between caregivers’ subjective assessments and objective neurophysiological measures of consciousness and pain was very poor.

Conclusions

Caregivers’ subjective assessment of level of consciousness and pain during CSD is unreliable compared with objective neurophysiological monitoring. Our results suggest that assessments of patient comfort during CSD could have been improved substantially by including objective monitoring of level of consciousness and pain.

Trial Registration

The protocol for this observational study has been registered retrospectively at Clinical-Trials.gov (ID NCT03273244).

Heart Rate Variability (HRV) and Pulse Rate Variability (PRV) for the Assessment of Autonomic Responses

Introduction: Heart Rate Variability (HRV) and Pulse Rate Variability (PRV), are non-invasive techniques for monitoring changes in the cardiac cycle. Both techniques have been used for assessing the autonomic activity. Although highly correlated in healthy subjects, differences in HRV and PRV have been observed under various physiological conditions. The reasons for their disparities in assessing the degree of autonomic activity remains unknown.

Methods: To investigate the differences between HRV and PRV, a whole-body cold exposure (CE) study was conducted on 20 healthy volunteers (11 male and 9 female, 30.3 ± 10.4 years old), where PRV indices were measured from red photoplethysmography signals acquired from central (ear canal, ear lobe) and peripheral sites (finger and toe), and HRV indices from the ECG signal. PRV and HRV indices were used to assess the effects of CE upon the autonomic control in peripheral and core vasculature, and on the relationship between HRV and PRV. The hypotheses underlying the experiment were that PRV from central vasculature is less affected by CE than PRV from the peripheries, and that PRV from peripheral and central vasculature differ with HRV to a different extent, especially during CE.

Results: Most of the PRV time-domain and Poincaré plot indices increased during cold exposure. Frequency-domain parameters also showed differences except for relative-power frequency-domain parameters, which remained unchanged. HRV-derived parameters showed a similar behavior but were less affected than PRV. When PRV and HRV parameters were compared, time-domain, absolute-power frequency-domain, and non-linear indices showed differences among stages from most of the locations. Bland-Altman analysis showed that the relationship between HRV and PRV was affected by CE, and that it recovered faster in the core vasculature after CE.

Conclusion: PRV responds to cold exposure differently to HRV, especially in peripheral sites such as the finger and the toe, and may have different information not available in HRV due to its non-localized nature. Hence, multi-site PRV shows promise for assessing the autonomic activity on different body locations and under different circumstances, which could allow for further understanding of the localized responses of the autonomic nervous system.

Review of different methods used for clinical recognition and assessment of pain in dogs and cats

In light of the need to perform surgical techniques and the importance of animal welfare because of acute pain, the objectives of the veterinary anaesthetists are to manage muscle relaxation and adequate analgesia in order to conserve a balance in the autonomic nervous system, enhance the action of the parasympathetic system in the face of the emerging action of the sympathetic portion provoked by the surgeon, and maintain a balance among them. The aim of the present review is to describe different evaluation criteria for acute pain using unidimensional and multidimensional scales, correlating these findings to parasympathetic tone activity (PTA) and bispectral index (BIS) assessment, to conduct an objective evaluation of pain that patients (dog or cat) perceives, in order to administrate an adequate analgesic treatment in each case. In conclusion, this integral, objective evaluation will allow veterinarians – especially anaesthesiologists – to improve the management of pain in the patients.

Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU

OBJECTIVE

To update and expand the 2013 Clinical Practice Guidelines for the Management of Pain, Agitation, and Delirium in Adult Patients in the ICU.

DESIGN

Thirty-two international experts, four methodologists, and four critical illness survivors met virtually at least monthly. All section groups gathered face-to-face at annual Society of Critical Care Medicine congresses; virtual connections included those unable to attend. A formal conflict of interest policy was developed a priori and enforced throughout the process. Teleconferences and electronic discussions among subgroups and whole panel were part of the guidelines' development. A general content review was completed face-to-face by all panel members in January 2017.

METHODS

Content experts, methodologists, and ICU survivors were represented in each of the five sections of the guidelines: Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption). Each section created Population, Intervention, Comparison, and Outcome, and nonactionable, descriptive questions based on perceived clinical relevance. The guideline group then voted their ranking, and patients prioritized their importance. For each Population, Intervention, Comparison, and Outcome question, sections searched the best available evidence, determined its quality, and formulated recommendations as "strong," "conditional," or "good" practice statements based on Grading of Recommendations Assessment, Development and Evaluation principles. In addition, evidence gaps and clinical caveats were explicitly identified.

RESULTS

The Pain, Agitation/Sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) panel issued 37 recommendations (three strong and 34 conditional), two good practice statements, and 32 ungraded, nonactionable statements. Three questions from the patient-centered prioritized question list remained without recommendation.

CONCLUSIONS

We found substantial agreement among a large, interdisciplinary cohort of international experts regarding evidence supporting recommendations, and the remaining literature gaps in the assessment, prevention, and treatment of Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) in critically ill adults. Highlighting this evidence and the research needs will improve Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) management and provide the foundation for improved outcomes and science in this vulnerable population.

Comparison of multiple cardiac signal acquisition technologies for heart rate variability analysis

Heart rate variability analysis is a recognized non-invasive tool that is used to assess autonomic nervous system regulation in various clinical settings and medical conditions. A wide variety of HRV analysis methods have been proposed, but they all require a certain number of cardiac beats intervals. There are many ways to record cardiac activity: electrocardiography, phonocardiography, plethysmocardiography, seismocardiography. However, the feasibility of performing HRV analysis with these technologies and particularly their ability to detect autonomic nervous system changes still has to be studied. In this study, we developed a technology allowing the simultaneous monitoring of electrocardiography, phonocardiography, seismocardiography, photoplethysmocardiography and piezoplethysmocardiography and investigated whether these sensors could be used for HRV analysis. We therefore tested the evolution of several HRV parameters computed from several sensors before, during and after a postural change. The main findings of our study is that even if most sensors were suitable for mean HR computation, some of them demonstrated limited agreement for several HRV analyses methods. We also demonstrated that piezoplethysmocardiography showed better agreement with ECG than other sensors for most HRV indexes.

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

BACKGROUND

Awareness and pain during palliative sedation is typically assessed by observational scales, but the use of such scales has been put into question.

CASE PRESENTATION

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.

CASE MANAGEMENT

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).

CASE OUTCOME

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.

CONCLUSION

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 the assessment of pain in critically ill patients: a diagnostic accuracy study

Background

Behavioural pain tools are used in Intensive Care Unit (ICU) patients unable to self-report their pain-intensity but need sustained efforts to educate and train the ICU team because of the subjective nature of these clinical tools. This study measured the validity and performance of an electrophysiological monitoring tool based on the spectral analysis of heart rate variability, the Analgesia Nociception Index (ANI) which varies from 0 (minimal parasympathetic tone, maximal stress-response and pain) to 100 (maximal parasympathetic tone, minimal stress-response and pain).

Methods

Mean-ANI (ANIm) and Instant-ANI (ANIi) were continuously recorded then compared with the Behavioral Pain Scale (BPS) before, during and after routine care procedures in critically-ill non-comatose patients.

Results

969 assessments were performed in 110 patients. ANIi was the most discriminative pain tool. It was significantly correlated with BPS (r=-0.30; 95%CI -0.37 to -0.25; P<0.001). For an ANIi threshold of 42.5, the sensitivity, specificity, positive and negative predictive values were respectively 61.4%, 77.4%, 37.0%, and 90.4%. Compared with the BPS, ANIi had no significantly different ability to change during turning and tracheal-suctioning but changed significantly more during dressing change. ANIi increased independently with age, obesity and severity of illness, and controlled mechanical-ventilation, vasopressors use and analgesia. ANIi decreased independently when vigilance status and respiratory rate increased. ANIm demonstrated poor psychometric properties to detect pain.

Conclusions

Despite low sensitivity/specificity, ANIi≥43 had a Negative-Predictive-Value of 90%. Hence ANIi may be of highest benefit for excluding significant pain. A randomized controlled trial should compare sedation-analgesia protocols based on ANIi to presently recommended behavioural-pain-tools.

Chronic Pain and Chronic Opioid Use After Intensive Care Discharge - Is It Time to Change Practice?

Almost half of patients treated on intensive care unit (ICU) experience moderate to severe pain. Managing pain in the critically ill patient is challenging, as their pain is complex with multiple causes. Pharmacological treatment often focuses on opioids, and over a prolonged admission this can represent high cumulative doses which risk opioid dependence at discharge. Despite analgesia the incidence of chronic pain after treatment on ICU is high ranging from 33-73%. Measures need to be taken to prevent the transition from acute to chronic pain, whilst avoiding opioid overuse. This narrative review discusses preventive measures for the development of chronic pain in ICU patients. It considers a number of strategies that can be employed including non-opioid analgesics, regional analgesia, and non-pharmacological methods. We reason that individualized pain management plans should become the cornerstone for critically ill patients to facilitate physical and psychological well being after discharge from critical care and hospital.

Sharp transection of the suspensory ligament as an alternative to digital strumming during canine ovariohysterectomy

OBJECTIVE

To compare time efficiency and nociceptive input between digital strumming (DS) and sharp transection (ST) of the suspensory ligament during ovariohysterectomy (OVH).

STUDY DESIGN

Randomized controlled trial.

ANIMALS

30 adult female dogs.

METHODS

Dogs were randomly assigned to ST or DS procedures. Measures of nociception were assessed through measurements of preoperative and intraoperative heart rate during manipulation of the suspensory ligament. Measures of pain were assessed through preoperative and postoperative pain scores by using the short form Glasgow Composite Pain Scale. Time efficiency was measured through total surgical time and the time to release each suspensory ligament.

RESULTS

After body weight was accounted for, the total surgical time was 1.1 minutes (P = .06) faster for ST than for DS, and each additional kilogram of body weight increased total surgical time by 0.1 minutes (P = .02). Digital strumming had 30.6-fold greater odds of taking greater than 1 minute compared with ST (P = .001). The heart rate from baseline to peak was 7.4 beats per minute lower in the ST group than in the DS group (P = .06). No complications were observed, and there was no difference in postoperative pain scores between treatments.

CONCLUSION

Sharp transection was faster and generated less intraoperative acceleration in heart rate but did not differ in postoperative outcomes compared with DS.

CLINICAL SIGNIFICANCE

Sharp transection is a viable alternative to DS for breakdown of the suspensory ligament during canine OVH. Sharp transection may improve surgical efficiency, especially when performing large volumes in the spay/neuter setting and could influence veterinary student training.

[Not Available]

The 2018 topics were « burns to the upper limb, hand excluded » and « advances in analgesia and sedation ». The authors used both the notes they took during the session and video footage to write this report. The reader should get in touch with the lecturer if more in-depth information is required.

Heart rate variability: implications for perioperative anesthesia care

PURPOSE OF REVIEW

Heart rate variability (HRV) is a measure of the balance between both the parasympathetic and sympathetic nervous system and may provide useful information for anesthesia care providers. HRV may offer predictive information about critically ill and operative patients. Further, HRV collection provides real-time information of patient autonomic nervous system status and may allow tailoring of the analgesia for patients in the ICU and operating room.

RECENT FINDINGS

Reduced and abnormal resting HRV predict sudden and nonsudden cardiac death. Recent evidence shows that decreased HRV correlates with worsened outcomes in both trauma patients and patients with sepsis, as well as the risk of developing hypotension after induction of general anesthesia and placement of intrathecal local anesthesia. In addition, HRV appears to provide an accurate assessment of the nociception-analgesia balance in deeply sedated ICU patients and those under general anesthesia.

SUMMARY

No study has assessed the prognostic value of preoperative HRV in patients presenting for surgery. Use of HRV for patient risk stratification and intraoperative analgesia management may allow tailored perioperative care and improved outcomes. If intraoperative HRV data leads to decreased perioperative opioid use, opioid-related adverse events, a serious perioperative issue, may be decreased.

CLINICAL TRIALS REGISTRATION

Not applicable.

Comfort in palliative sedation (Compas): a transdisciplinary mixed method study protocol for linking objective assessments to subjective experiences

BACKGROUND

In case of untreatable suffering at the end of life, palliative sedation may be chosen to assure comfort by reducing the patient's level of consciousness. An important question here is whether such sedated patients are completely free of pain. Because these patients cannot communicate anymore, caregivers have to rely on observation to assess the patient's comfort. Recently however, more sophisticated techniques from the neurosciences have shown that sometimes consciousness and pain are undetectable with these traditional behavioral methods. The aim of this study is to better understand how unconscious palliative sedated patients experience the last days of their life and to find out if they are really free of pain.

METHODS

In this study we will observe 40 patients starting with initiation of palliative sedation until death. Assessment of comfort based on behavioral observations will be related with the results from a NeuroSense monitor, an EEG-based monitor used for evaluation of the adequacy of anesthesia and sedation in the operating room and an ECG-based Analgesia Nociception Index (ANI) monitor, which informs about comfort or discomfort condition, based on the parasympathetic tone. An innovative and challenging aspect of this study is its qualitative approach; "objective" and "subjective" data will be linked to achieve a holistic understanding of the study topic. The following data will be collected: assessment of pain/comfort by the patients themselves (if possible) by scoring a Visual Analogue Scale (VAS); brain function monitoring; monitoring of parasympathetic tone; caregivers' assessment (pain, awareness, communication); relatives' perception of the quality of the dying process; assessment by 2 trained investigators using observational scales; video and audio registration.

DISCUSSION

Measuring pain and awareness in non-communicative dying patients is both technically and ethically challenging. ANI and EEG have shown to be promising technologies to detect pain that otherwise cannot be detected with the "traditional" methods. Although these technologies have the potential to provide objective quantifiable indicators for distress and awareness in non-communicative patients, strikingly they have not yet been used to check whether the current assessments for non-communicative patients are reliable.

TRIAL REGISTRATION

The study is registered on ClinicalTrials.gov (Identifier: NCT03273244 ; registration date: 7.9.2017).

Differences in heart rate variability may be related to the appearance of postoperative pain in patients undergoing breast cancer surgery

Background

Some reports have highlighted the relationship between heart rate variability (HRV) and the degree of postoperative pain experienced. This study retrospectively examined whether differences in heart rate variability may be related to the appearance of postoperative pain in patients undergoing breast cancer surgery.

Findings

We retrospectively analyzed 20 postoperative patients who had no pain immediately upon admission to the post-anesthesia care unit (PACU), divided into two groups: group A (n = 16) had no pain on admission to PACU, remaining pain free upon discharge (12 h after surgery); group B (n = 4) comprised patients with no pain on admission to PACU but who experienced increasing pain requiring intervention in PACU 1 h after surgery. HRV was measured immediately on admission to PACU and 2 h after surgery; this included variables of low-frequency power (LF), high-frequency power (HF), and LF/HF. There were significant differences in HF and LF/HF in group A compared with those in group B on admission to PACU (immediately after arrival): HF, group A, 35.4 ± 18.1; group B, 64.2 ± 9.5*; LF/HF group A, 2.7 ± 2.4; group B, 0.6 ± 0.2*, *p < 0.05). There was no significant difference in the Numerical rating scale (NRS) between the two groups immediately after admission to PACU. At 1 h after the surgery, NRS in Group B increased, and there were significant differences in NRS values between the two groups 1 h after surgery prior to the use of analgesic agents (NRS, group A, 1.0 ± 0.9; group B, 4.0 ± 1.4*, *p < 0.01). Patients in group A required no analgesic agents for at least 12 h after surgery.

Conclusions

Lower HF and higher LF/HF values immediately after arrival in PACU were observed in patients remaining pain free for 12 h after surgery compared to patients who experienced increasing postoperative pain 1 h after surgery. The data suggest that differences in HRV may be related to the appearance of postoperative pain.

Heart Rate Variability: A Novel Modality for Diagnosing Neuropathic Pain after Spinal Cord Injury

Background: Heart rate variability (HRV), the physiological variance in the heart's R-R interval length, can be analyzed to produce various parameters reflective of one's autonomic balance. HRV analysis may be used to capture those autonomic aberrations associated with chronic neuropathic pain (NP) in spinal cord injury (SCI). This study assesses the capacity of HRV parameters to diagnose NP in an SCI cohort.

Methods: An electrocardiogram (ECG) was collected at rest from able bodied participants (AB, n = 15), participants with SCI only (SCI-NP, n = 11), and those with SCI and NP (SCI+NP, n = 20). HRV parameters were analyzed using conventional time and frequency analysis.

Results: At rest, there were no heart rate differences amongst groups. However, SCI+NP participants demonstrated lower overall HRV, as determined by the SDNN time domain parameter, compared to either AB (p < 0.01) or SCI-NP (p < 0.05) groups. Moreover, AB and SCI-NP participants were statistically comparable for all HRV time and frequency domain parameters. Additional analyses demonstrated no differences in HRV parameters between T4, above vs. T5, below SCI groups (for all parameters: p > 0.15) or between C8, above vs. T1, below SCI groups (p > 0.30).

Conclusions: Participants with SCI and NP exhibit a lower overall HRV, which can be determined by HRV time domain parameter SDNN. HRV analysis is an innovative modality with the capacity for objective quantification of chronic NP in participants with SCI.

Evaluation of the Parasympathetic Tone Activity (PTA) index to assess the analgesia/nociception balance in anaesthetised dogs

The Parasympathetic Tone Activity (PTA) is an index based on the analysis of heart rate variability that has been recently developed to assess the analgesia/nociception balance in anaesthetised animals. The present study aimed to evaluate its performance in dogs undergoing surgery. Thirty dogs admitted for elective surgeries, were anaesthetised with a standardised protocol. PTA, heart rate (HR), systolic blood pressure (SBP) and HDR (defined as an increase by >20% in HR and/or SBP within 5min) were assessed at the following predefined time-points: T_StSt (steady-state, after induction of anaesthesia and before start of surgery), T_Clamp (clamping of surgical drapes on the skin), T_Cut (cutaneous incision), T_PrePTA (retrospectively assessed 1min before a PTA decline of at least 20%) and T_EndIso (isoflurane discontinuation). The dynamic variation of PTA over 1min (∆PTA) was calculated at each predefined time-points and its performance to predict HDR was assessed by building Receiver Operating Characteristics (ROC) curves. A significant decrease of PTA (p<0.002) was detected 1min after T_Clamp, T_Cut and T_PrePTA followed by a significant increase in HR and/or SBP within 5min after the time points (p<0.01). The ΔPTA was associated with the following performance in predicting HDR: AUC ROC [95% CI]=0.80 [0.71 to 0.88] (p<0.05), with a sensitivity of 77% and a specificity of 72% for a threshold value of -18%. Although encouraging, the performance of the PTA index and its dynamic variation needs to be further evaluated, particularly in different clinical contexts.

Pain Measurement in Mechanically Ventilated Patients with Traumatic Brain Injury: Behavioral Pain Tools Versus Analgesia Nociception Index

Introduction:

Pain is highly prevalent in critically ill trauma patients, especially those with a traumatic brain injury (TBI). Behavioral pain tools such as the behavioral pain scale (BPS) and critical-care pain observation tool are recommended for sedated noncommunicative patients. Analysis of heart rate variability (HRV) is a noninvasive method to evaluate autonomic nervous system activity. The analgesia nociception index (ANI) device (Physiodoloris^®, MDoloris Medical Systems, Loos, France) allows noninvasive HRV analysis. The ANI assesses the relative parasympathetic tone as a surrogate for antinociception/nociception balance in sedated patients. The primary aim of our study was to evaluate the effectiveness of ANI in detecting pain in TBI patients. The secondary aim was to evaluate the impact of norepinephrine use on ANI effectiveness and to determine the correlation between ANI and BPS.

Methods:

We performed a prospective observational study in 21 deeply sedated TBI patients. Exclusion criteria were nonsinus cardiac rhythm; presence of pacemaker; atropine or isoprenaline treatment; neuromuscular blocking agents; and major cognitive impairment. Heart rate, blood pressure, and ANI were continuously recorded using the Physiodoloris^® device at rest (T1), during (T2), and after the end (T3) of the painful stimulus (tracheal suctioning).

Results:

In total, 100 observations were scored. ANI was significantly lower at T2 (Median [min – max] 54.5 [22–100]) compared with T1 (90.5 [50–100], P < 0.0001) and T3 (82 [36–100], P < 0.0001). Similar results were found in the subgroups of patients with (65 measurements) or without (35) norepinephrine. During procedure, a negative linear relationship was observed between ANI and BPS (r² = −0.469, P < 0.001). At the threshold of 50, the sensitivity and specificity of ANI to detect patients with BPS ≥ 5 were 73% and 62%, respectively, with a negative predictive value of 86%.

Discussion:

Our results suggest that ANI is effective in detecting pain in ventilated sedated TBI patients, including those patients treated with norepinephrine.

Paracetamol and morphine for infant and neonatal pain; still a long way to go?

INTRODUCTION

Pharmacologic pain management in newborns and infants is often based on limited scientific data. To close the knowledge gap, drug-related research in this population is increasingly supported by the authorities, but remains very challenging. This review summarizes the challenges of analgesic studies in newborns and infants on morphine and paracetamol (acetaminophen). Areas covered: Aspects such as the definition and multimodal character of pain are reflected to newborn infants. Specific problems addressed include defining pharmacodynamic endpoints, performing clinical trials in this population and assessing developmental changes in both pharmacokinetics and pharmacodynamics. Expert commentary: Neonatal and infant pain management research faces two major challenges: lack of clear biomarkers and very heterogeneous pharmacokinetics and pharmacodynamics of analgesics. There is a clear call for integral research addressing the multimodality of pain in this population and further developing population pharmacokinetic models towards physiology-based models.