Newborn Infant Pain Assessment Using Heart Rate Variability Analysis

Pain and heart rate variability in neonates receiving dexmedetomidine

INTRODUCTION

Neonates in a NICU experience pain. Based on the cardiovascular and nociceptive systems link, a Newborn Infant Parasympathetic Evaluation (NIPE) monitor was designed to assess pain. The use of α2-agonists as analgesic-sedative drugs has increased in neonates. Given their effect on the autonomic system, we hypothesized that their use may alter NIPE's measurement capacity.

METHODS

Data were prospectively collected. The included patients were evaluated using combined pain assessment systems.

RESULTS

Sixteen newborns requiring sedoanalgesia underwent a total of 84 pain assessments. A good correlation was found between the NIPE-index and the COMFORT-neo and the crSO2 (cerebral regional oxygen saturation). No correlation was found in premature infants. By sedation group, the correlation remained in those receiving α2-agonist.

CONCLUSION

NIPE is a reliable tool for pain assessment. Further studies in premature infants are needed. The use of α2-agonist does not alter the measuring capacity of NIPE. The correlation between NIPE-index and crSO2 was also demonstrated.

[Fetal monitoring: Current limitations and new approaches based on analysis of the fetal autonomic nervous system]

OBJECTIVE

Currently, fetal monitoring during labor is based on visual analysis of the fetal heart rate (FHR). This test is imperfect, with high intra- and inter-observer variability and a moderate to poor prediction of the occurrence of neonatal acidosis or anoxic-ischaemic encephalopathy. In situations where there is an intermediate risk of acidosis, it is possible to use second-line tests such as blood scalp sampling (with pH or lactate measurement) or ST segment analysis of the fetal ECG. However, these invasive tests have many limitations and their place is debated. Some authors suggest a more physiological approach to FHR assessment. The main actor in maintaining fetal homeostasis is the autonomic nervous system (ANS). Its activity can be assessed by analysing heart rate variability (HRV). The aim is to assess whether HRV can be used to identify situations at risk of acidosis.

MATERIALS AND METHODS

Our team has developed an index, the Fetal Stress Index, to measure HRV. To test it in a situation of acidosis, we used a pregnant ewe model. We also developed in parallel a human fetal ECG recording system.

RESULTS

In our experimental model, we have shown that this index reflects variations in the parasympathetic system and correlates with the onset of acidosis. As its use in clinical practice requires the acquisition of a beat-to-beat FHR signal, we have also developed an abdominal patch that allows highly accurate analysis of the fetal ECG.

CONCLUSION

The future is therefore to validate the FSI as a marker of acidosis in a prospective cohort using the signal obtained from our patch. This could be a new tool for fetal monitoring during labor.

Prolonged pain in premature neonates hospitalised in neonatal intensive care units: A scoping review

BACKGROUND

Exposure to repetitive pain during the neonatal period has been shown to have important short and long-term effects on the neurodevelopment of the premature neonate and can contribute to experienced prolonged pain. A uniform taxonomy of neonatal prolonged pain is still lacking to this day which contributes to suboptimal prolonged pain management in neonatal intensive care units. Accordingly, a scoping review exploring the state of knowledge about prolonged pain in preterm neonates hospitalised in the neonatal intensive care unit will contribute to the developing field of neonatal prolonged pain and provide recommendations for clinical prolonged pain management.

OBJECTIVE

To determine the scope, extent, and nature of the available literature on prolonged pain in premature neonates hospitalised in neonatal intensive care units.

DESIGN

Scoping review.

METHODS

An electronic search was conducted from inception to November 2023 in the databases of CINAHL, PubMed, Medline, Web of Science, GeryLit.org and Grey Source Index. Included studies discussed concepts related to neonatal prolonged pain such as definitions of prolonged pain, indicators of prolonged pain, contexts that result in prolonged pain, prolonged pain evaluation tools, consequences of prolonged pain and interventions for prolonged pain management.

RESULTS

Key concepts of neonatal prolonged pain were identified in the 86 included articles of this scoping review such as definitions (n = 26), indicators (n = 39), contexts (n = 49), scales (n = 56), consequences of prolonged pain (n = 30) and possible interventions for prolonged pain management (n = 22). Whilst a consensus on a definition has yet to be achieved, no proximate event was shown to cause prolonged pain and a time criterion was identified by authors as being relevant in defining prolonged pain. Interestingly, the context of hospitalisation was identified as being the most indicative of prolonged pain in premature neonates and should guide its evaluation and management, whilst only limited pain management interventions and consequences were discussed.

CONCLUSION

The findings of this scoping review contribute to the foundation of growing knowledge in neonatal prolonged pain and shed light on the ambiguity that currently exists on this topic in the scientific literature. This review summarises knowledge of key concepts necessary for a better understanding of prolonged pain and stresses the importance of considering contexts of hospitalisation for prolonged pain evaluation and management in neonatal intensive care units, with the objective of improving developmental outcomes of premature neonates.

TWEETABLE ABSTRACT

A scoping review reveals that the contexts of prolonged pain in premature neonates hospitalised in the neonatal intensive care unit are essential in guiding its evaluation and management.

The Effect of Breast Milk Odor on the Pain and Stress Levels of the Newborn During the Endotracheal Suction Procedure

Objective: The study aimed to determine the effect of the breast milk odor on the pain and stress levels of the newborn during the endotracheal suction procedure. Method: The study was conducted in the randomized-controlled experimental design at the neonatal intensive care unit of the hospital in eastern Turkey between March 2022 and December 2023. The study population included newborns at the 37th to 41st gestational weeks who were receiving mechanical ventilation treatment in the neonatal intensive care unit of a hospital in eastern Turkey. All newborns who met the inclusion criteria during the data collection phase were included in the study. The study was completed with 88 newborns (44 in the intervention group and 44 in the control group). The Newborn Introductory Information Form, ALPS-Neo Newborn Pain and Stress Assessment Scale, and follow-up form were used to collect the study data. The breast milk odor of the mothers of the newborns was used as the intervention group in the study. The mothers of the newborns were contacted to obtain breast milk, and the information was obtained from the mother on the day of the procedure. One milliliter of breast milk was taken and dropped into a sterile sponge, and it was held 10 cm away from the baby's nose from 5 minutes before to 5 minutes after endotracheal suction. A routine endotracheal suction process was performed in the control group. Ethical principles were followed in the study. Results: We found that the intervention group's pain and stress score averages were lower than the control group during and after the endotracheal suction procedure (p < 0.05). Conclusion: We found that the breast milk odor reduced the pain, stress levels, and crying duration of newborns during the endotracheal suction process.

Sensitivity and Specificity of the Newborn Infant Parasympathetic Evaluation Index in Pain Assessment of Very Low Birth Weight Infants

OBJECTIVE

This article describes the results of a study investigating the sensitivity and specificity of the Newborn Infant Parasympathetic Evaluation (NIPE) index for detecting the physiological changes resulting from nociception in painful procedures in very low birth weight (VLBW) infants.

STUDY DESIGN

A prospective observational study was carried on of 44 newborns at 23 to 32 weeks' gestational age. The sensitivity and specificity of the NIPE index are analyzed using a receiver operating characteristic curve. Most of the painful procedures performed were skin-lancing and venipunctures. Nonpainful procedures consist of no intervention, with an interval of at least 1 hour with painful procedures in each newborn.

RESULTS

The accuracy of the NIPE index to diagnose mild nociceptive stimulation in VLBW newborns is 73.2%.

CONCLUSION

The NIPE index is a useful technique for assessing nociceptive stimulation in newborns, presenting less observer-dependent variability than other pain assessment scales.

KEY POINTS

· The NIPE index offers an objective assessment of pain.. · Moderate-high sensitivity of the NIPE index in the evaluation of pain in premature newborns.. · Painful procedures in VLBW newborns are reflected as a decrease in the NIPE score..

Biomarkers for assessing pain and pain relief in the neonatal intensive care unit

Newborns admitted to the neonatal intensive care unit (NICU) regularly undergo painful procedures and may face various painful conditions such as postoperative pain. Optimal management of pain in these vulnerable preterm and term born neonates is crucial to ensure their comfort and prevent negative consequences of neonatal pain. This entails accurate and timely identification of pain, non-pharmacological pain treatment and if needed administration of analgesic therapy, evaluation of treatment effectiveness, and monitoring of adverse effects. Despite the widely recognized importance of pain management, pain assessment in neonates has thus far proven to be a challenge. As self-report, the gold standard for pain assessment, is not possible in neonates, other methods are needed. Several observational pain scales have been developed, but these often rely on snapshot and largely subjective observations and may fail to capture pain in certain conditions. Incorporation of biomarkers alongside observational pain scores holds promise in enhancing pain assessment and, by extension, optimizing pain treatment and neonatal outcomes. This review explores the possibilities of integrating biomarkers in pain assessment in the NICU.

What to consider for ECG in mice-with special emphasis on telemetry

Genetically or surgically altered mice are commonly used as models of human cardiovascular diseases. Electrocardiography (ECG) is the gold standard to assess cardiac electrophysiology as well as to identify cardiac phenotypes and responses to pharmacological and surgical interventions. A variety of methods are used for mouse ECG acquisition under diverse conditions, making it difficult to compare different results. Non-invasive techniques allow only short-term data acquisition and are prone to stress or anesthesia related changes in cardiac activity. Telemetry offers continuous long-term acquisition of ECG data in conscious freely moving mice in their home cage environment. Additionally, it allows acquiring data 24/7 during different activities, can be combined with different challenges and most telemetry systems collect additional physiological parameters simultaneously. However, telemetry transmitters require surgical implantation, the equipment for data acquisition is relatively expensive and analysis of the vast number of ECG data is challenging and time-consuming. This review highlights the limits of non-invasive methods with respect to telemetry. In particular, primary screening using non-invasive methods can give a first hint; however, subtle cardiac phenotypes might be masked or compensated due to anesthesia and stress during these procedures. In addition, we detail the key differences between the mouse and human ECG. It is crucial to consider these differences when analyzing ECG data in order to properly translate the insights gained from murine models to human conditions.

Heart rate monitoring to detect acute pain in non-verbal patients: a study protocol for a randomized controlled clinical trial

BACKGROUND

Autism entails reduced communicative abilities. Approximately 30% of individuals with autism have intellectual disability (ID). Some people with autism and ID are virtually non-communicative and unable to notify their caregivers when they are in pain. In a pilot study, we showed that heart rate (HR) monitoring may identify painful situations in this patient group, as HR increases in acutely painful situations.

OBJECTIVES

This study aims to generate knowledge to reduce the number of painful episodes in non-communicative patients' everyday lives. We will 1) assess the effectiveness of HR as a tool for identifying potentially painful care procedures, 2) test the effect of HR-informed changes in potentially painful care procedures on biomarkers of pain, and 3) assess how six weeks of communication through HR affects the quality of communication between patient and caregiver.

METHODS

We will recruit 38 non-communicative patients with autism and ID residing in care homes.

ASSESSMENTS

HR is measured continuously to identify acutely painful situations. HR variability and pain-related cytokines (MCP-1, IL-1RA, IL-8, TGFβ1, and IL-17) are collected as measures of long-term pain. Caregivers will be asked to what degree they observe pain in their patients and how well they believe they understand their patient's expressions of emotion and pain. Pre-intervention: HR is measured 8 h/day over 2 weeks to identify potentially painful situations across four settings: physiotherapy, cast use, lifting, and personal hygiene.

INTERVENTION

Changes in procedures for identified painful situations are in the form of changes in 1) physiotherapy techniques, 2) preparations for putting on casts, 3) lifting techniques or 4) personal hygiene procedures.

DESIGN

Nineteen patients will start intervention in week 3 while 19 patients will continue data collection for another 2 weeks before procedure changes are introduced. This is done to distinguish between specific effects of changes in procedures and non-specific effects, such as caregivers increased attention.

DISCUSSION

This study will advance the field of wearable physiological sensor use in patient care.

TRIAL REGISTRATION

Registered prospectively at ClinicalTrials.gov (NCT05738278).

Experimental Exploration of Multilevel Human Pain Assessment Using Blood Volume Pulse (BVP) Signals

Critically ill patients often lack cognitive or communicative functions, making it challenging to assess their pain levels using self-reporting mechanisms. There is an urgent need for an accurate system that can assess pain levels without relying on patient-reported information. Blood volume pulse (BVP) is a relatively unexplored physiological measure with the potential to assess pain levels. This study aims to develop an accurate pain intensity classification system based on BVP signals through comprehensive experimental analysis. Twenty-two healthy subjects participated in the study, in which we analyzed the classification performance of BVP signals for various pain intensities using time, frequency, and morphological features through fourteen different machine learning classifiers. Three experiments were conducted using leave-one-subject-out cross-validation to better examine the hidden signatures of BVP signals for pain level classification. The results of the experiments showed that BVP signals combined with machine learning can provide an objective and quantitative evaluation of pain levels in clinical settings. Specifically, no pain and high pain BVP signals were classified with 96.6% accuracy, 100% sensitivity, and 91.6% specificity using a combination of time, frequency, and morphological features with artificial neural networks (ANNs). The classification of no pain and low pain BVP signals yielded 83.3% accuracy using a combination of time and morphological features with the AdaBoost classifier. Finally, the multi-class experiment, which classified no pain, low pain, and high pain, achieved 69% overall accuracy using a combination of time and morphological features with ANN. In conclusion, the experimental results suggest that BVP signals combined with machine learning can offer an objective and reliable assessment of pain levels in clinical settings.

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.

Assessment of neonatal pain: uni- and multidimensional evaluation scales

Neonatal pain is a problem that is easily overlooked. According to the status quo of neonatal pain management, commonly 9 scales are used for evaluation of neonatal pain; details of the specific indicators, such as the applicable neonatal gestational age range, score, and the type of pain, for the domestic references are provided so as to provide reference for the proper evaluation and standardized management of neonatal pain, as well as to promote the management level of neonatal pain.

The Impact of Breast Milk Taste and Smell in Reducing Pain in Infants Undergoing Blood Drawing Procedure: A Randomized Controlled Study

Background: Infants hospitalized in neonatal intensive care units (NICUs) are exposed to numerous procedures that cause pain. In the literature, pain management methods in infants are evaluated by using breast milk in various ways. However, no study was found on whether the smell of breast milk, its taste, or both are more effective in pain management. Aim: The purpose of this study is to comparatively investigate the efficacy of breast milk taste and/or smell in reducing pain responses in infants undergoing a blood drawing procedure. Methods: The population of this study, which has a randomized controlled prospective design, consisted of infants who were treated in a NICU and met the inclusion criteria. The heart rate (HR), oxygen saturation (SpO₂), and pain of the infants were evaluated before, during, and after the blood drawing procedure in all groups. Results: During and after the procedure, there were significant differences in terms of pain levels, SpO₂ levels, and HR between the groups (p = 0.000). The lowest pain score during the procedure was found in the infants to whom breast milk taste and smell were administered together. The group with the second-lowest pain score was exposed to the taste of breast milk. The group with the highest pain score was the control group. Conclusion: Breast milk smell and taste are recommended for use as a nursing intervention to reduce pain, decrease the HR, and increase SpO₂ in the NICU during painful procedures. Future research needs to explore different interventional practices.

Usefulness of two types of pain monitors in newborns treated in NICU, in the opinion of experts: Results of the survey

Pain experienced in the neonatal period has been shown to have serious short- and long-term consequences. It is also known that painkillers have side effects and should not be abused. The basis of proper pain management is assessment of pain, which in newborns is very difficult due to the lack of verbal communication. In these patients, behavioural scales are used to assess pain, but they have numerous shortcomings. For this reason, many newborns treated in the ICU are at risk of pain, so instrumental methods of detecting and assessing the severity of pain are being sought. During three months, seven Polish NICUs conducted research with the use of NIPE and SCA monitors. After this time, the heads of these departments filled in questionnaires regarding their individual opinions on the usefulness of these devices. All respondents found pain monitors useful in the NICU. The NIPE monitor was rated slightly higher, as its usefulness in assessing the effectiveness of analgosedation and in the management of patients in the postoperative period was better rated. The high acceptance of both devices by legal guardians of newborns is noteworthy. It should be stated that in newborns, any way to improve pain monitoring is valuable. In the opinion of Polish experts, pain monitors are useful in NICU. The NIPE monitor was assessed a little higher and was considered useful in the assessment of analgosedation and in postoperative treatment. Pain monitors can provide valuable support for pain assessment in newborns treated in the NICU.

Long-Lasting Analgesia With Transdermal Fentanyl: A New Approach in Rat Neonatal Research

Background: With advances in neonatal care, management of prolonged pain in newborns is a daily concern. In addition to ethical considerations, pain in early life would have long-term effects and consequences. However, its treatment remains inadequate. It was therefore important to develop an experimental model of long-lasting analgesia for neonatal research. Materials and Methods: Experiments were performed in six groups of rats with transdermal fentanyl 0, 3, 12, 50, 100, or 200 μg/kg/h from second postnatal day (P2) until weaning. Assessment of analgesia was carried out at P21, with behavioral scores (ranging from 0 to 3) using a 4% formalin test. Plasma levels of fentanyl were determined by UPLC/TQD at P22. Growth rate was investigated. Results: Fentanyl 100 and 200 μg/kg/h reduced scores of formalin-evoked behavioral pain. They increased time spent in pain score 0 (8 min 55 s and 6 min 34 s versus 23 s in controls) as in low pain scores 1 and 2, and decreased time in the most severe pain score 3 (19 min 56 s and 17 min 39 s versus 44 min 15 s). Fentanylemia increased in a dose-dependent manner from 50 μg/kg/h (2.36 ± 0.64 ng/ml) to 200 μg/kg/h (8.66 ± 1.80 ng/ml). Concerning growth, no difference was observed except weaker growth from P17 to P22 with 200 μg/kg/h. Clinically, we noticed no visible side effect from 3 to 100 μg/kg/h. Concomitantly, 200 μg/kg/h was responsible for ophthalmological side effects with appearance of corneal bilateral clouding in 90% pups. No difference was observed between male and female rats. Conclusion: Altogether, results indicate that transdermal fentanyl 100 μg/kg/h is an efficient therapeutic for long-lasting analgesia in lactating pups. This new model provides a useful tool for protection and welfare, and future opportunity for studying long-term health consequences of sustainable neonatal analgesia.

Heart Rate Variability as a Potential Indicator of Cancer Pain in a Mouse Model of Peritoneal Metastasis

Heart rate variability (HRV) is closely related to changes in the autonomic nervous system (ANS) associated with stress and pain. In this study, we investigated whether HRV could be used to assess cancer pain in mice with peritoneal metastases. At 12 days after cancer induction, positive indicators of pain such as physiological characteristics, appearance, posture, and activity were observed, and time- and frequency-domain HRV parameters such as mean R-R interval, square root of the mean squared differences of successive R-R intervals, and percentage of successive R-R interval differences greater than 5 ms, low frequency (LF), high frequency (HF), and ratio of LF and HF power, were found to be significantly decreased. These parameters returned to normal after analgesic administration. Our results indicate that overall ANS activity was decreased by cancer pain and that HRV could be a useful tool for assessing pain.

Vital signs as physiomarkers of neonatal sepsis

Neonatal sepsis accounts for significant morbidity and mortality, particularly among premature infants in the Neonatal Intensive Care Unit. Abnormal vital sign patterns serve as physiomarkers of sepsis and provide early warning of illness before overt clinical decompensation. The systemic inflammatory response to pathogens signals the autonomic nervous system, leading to changes in temperature, respiratory rate, heart rate, and blood pressure. In infants with comorbidities of prematurity, vital sign abnormalities often occur in the absence of infection, which confounds sepsis diagnosis. This review will cover the mechanisms of vital sign changes in neonatal sepsis, including the cholinergic anti-inflammatory pathway mediated by the vagus nerve, which is critical to the host response to infectious and inflammatory insults. We will also review the clinical implications of vital sign changes in neonatal sepsis, including their use in early warning scores and systems to direct clinicians to the bedside of infants with physiologic changes that might be due to sepsis. IMPACT: This manuscript summarizes and reviews the relevant literature on the physiological manifestations of neonatal sepsis and how we monitor and analyze these through vital signs and advanced analytics.

Neonatal heart rate variability: a contemporary scoping review of analysis methods and clinical applications

BACKGROUND

Neonatal heart rate variability (HRV) is widely used as a research tool. However, HRV calculation methods are highly variable making it difficult for comparisons between studies.

OBJECTIVES

To describe the different types of investigations where neonatal HRV was used, study characteristics, and types of analyses performed.

ELIGIBILITY CRITERIA

Human neonates ≤1 month of corrected age.

SOURCES OF EVIDENCE

A protocol and search strategy of the literature was developed in collaboration with the McGill University Health Center's librarians and articles were obtained from searches in the Biosis, Cochrane, Embase, Medline and Web of Science databases published between 1 January 2000 and 1 July 2020.

CHARTING METHODS

A single reviewer screened for eligibility and data were extracted from the included articles. Information collected included the study characteristics and population, type of HRV analysis used (time domain, frequency domain, non-linear, heart rate characteristics (HRC) parameters) and clinical applications (physiological and pathological conditions, responses to various stimuli and outcome prediction).

RESULTS

Of the 286 articles included, 171 (60%) were small single centre studies (sample size <50) performed on term infants (n=136). There were 138 different types of investigations reported: physiological investigations (n=162), responses to various stimuli (n=136), pathological conditions (n=109) and outcome predictor (n=30). Frequency domain analyses were used in 210 articles (73%), followed by time domain (n=139), non-linear methods (n=74) or HRC analyses (n=25). Additionally, over 60 different measures of HRV were reported; in the frequency domain analyses alone there were 29 different ranges used for the low frequency band and 46 for the high frequency band.

CONCLUSIONS

Neonatal HRV has been used in diverse types of investigations with significant lack of consistency in analysis methods applied. Specific guidelines for HRV analyses in neonates are needed to allow for comparisons between studies.

Evaluation of intraperitoneal administration of morphine on post-operative pain management after ovariohysterectomy in dogs

The present prospective randomized experimental study was designed to assess pain control with intraperitoneal morphine following ovariohysterectomy in dogs. A group of 12 mixed breed female dogs, aged 1-2 years, weighing 19.95 ± 0.95 kg were included. Forty minutes after sedation with 0.05 mg/kg intramuscular acepromazine 1%, anaesthesia was induced with propofol (4 mg/kg). The dogs were connected to the inhalation anaesthesia circuit using isoflurane. Ovariohysterectomy was performed, and before the closure of linea alba, the animals received intraperitoneal morphine (0.5 mg/kg) (in group M) and saline (0.2 ml/kg) (in group S). No significant difference was detected in total protein and glucose levels between the groups, while the cortisol level in group M was significantly lower than group S 1, 3 and 6 h after surgery. Furthermore, the comparison of the rectal temperature, heart rates and respiratory rates showed no major differences. Additionally, no significant alterations were detected between the groups considering the changes in the pain scores with simple descriptive score, Glasgow, University of Melbourne pain scale, sedation status and Sammarco methods. Finally, three cases in group S and two cases in group M were given an intramuscular analgesic rescue dose of morphine. Although a significant decline was observed in cortisol levels following intraperitoneal morphine administration, there were no beneficial changes in the efficiency of post-operative analgesia in status and clinical signs compared to the control group. Further studies are required to investigate intraperitoneal morphine effectiveness in post-operative pain management.

Pain Behavioural Response to Acoustic and Light Environmental Changes in Very Preterm Infants

Noise and high light illumination in the neonatal intensive care unit (NICU) are recognized as stressors that could alter the well-being and development of vulnerable preterm infants. This prospective observational study evaluated the pain behaviours of very preterm infants (VPIs) to sound peaks (SPs) and light levels variations (LLVs) in the NICU. We measured spontaneously occurring SPs and LLVs in the incubators of 26 VPIs over 10 h. Their behavioural responses were analysed through video recordings using the "Douleur Aigue du Nouveau-né" (DAN) scale. We compared the maximum DAN scores before and after environmental stimuli and the percentage of VPIs with a score ≥ 3 according to the type of stimuli. A total of 591 SPs and 278 LLVs were analysed. SPs of 5 to 15 dBA and LLVs significantly increased the maximum DAN scores compared to baseline. The occurrence of DAN scores ≥ 3 increased with both stressors, with a total of 16% of SPs and 8% of LLVs leading to quantifiable pain behaviour. Altogether, this study shows that VPIs are sensitive to SPs and LLVs, with a slighter higher sensitivity to SPs. The mechanisms leading to pain behaviours induced by noise and light changes should be evaluated further in the context of VPIs brain development. Our results provide further arguments to optimize the NICU sensory environment of neonatal units and to adapt it to the expectations and sensory abilities of VPIs.

Turkish validity and reliability of the COVERS pain scale

OBJECTIVE

The objective of this study is to determine the Turkish validity and reliability of COVERS.

METHODS

This study was conducted on 41 newborns as methodological design. The scales, such as newborn information form, COVERS, preterm infant pain profile (PIPP), and neonatal infant pain scale (NIPS), were used in the study. Validity (e.g., language, content concurrent, and construct) and internal consistency and inter-rater reliability of the scale were conducted.

RESULTS

It was found that COVERS showed a high correlation with PIPP and NIPS, and the item-total correlation of COVERS was above 0.30 during and after heel lance procedure. The Cronbach's α values were 0.77 and 0.83 during and after heel lance procedure, respectively. The kappa values of the items of COVERS were between 0.38 and 0.78 during heel lance procedure.

CONCLUSIONS

It was concluded in this study that there was a moderate correlation in intraclass correlation coefficients for scores of COVERS during both diaper change and heel lance procedures. It has been concluded that the scale is valid and reliable in 27-week-old and older newborns.

Available Instruments to Assess Pain in Infants

Pain assessment in newborns and infants is challenging for clinicians. Although behavioral and behavioral-physiological scales are validated pain assessment instruments, their use in this age group has significant limitations. In this review, we summarize the methods currently available for assessing pain in neonates and infants. It is possible that these pain detection methods are also useful for assessing the quality of anesthesia and analgosedation in these populations. Further research should be aimed at confirming the usefulness of these tools in infants and identifying additional pain assessment options for clinical practice.

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.

Exploration and Validation of Behavioral Pain Measures and Physiological Pain Measures Factor Structure Extracted From the Pain Assessment Tool Item Scores for Infants Admitted to Neonatal Intensive Care

OBJECTIVE

The objective of the study was to explore and then validate the factor structure of the Pain Assessment Tool (PAT).

MATERIALS AND METHODS

A retrospective medical record review was performed of all infants who were admitted to a neonatal intensive care unit between 2008 and 2018 and had 1 PAT assessment (n=2111). Scores on items of the PAT were collected. Infants were randomized to either the principal component analysis (n=1100) to explore the factor structure or confirmatory factor analysis (n=1011).

RESULTS

Infants in the 2 samples were demographically comparable. A 2-factor model, consisting of factors Behavioral and Physiological Pain Measures, was extracted, explaining 39.8% of the total variance. There was a low interfactor correlation (r=0.12), and both Behavioral (r=0.59) and Physiological Pain (r=0.37) Measures factor scores were correlated with nurses' perception of pain scores. When the frequencies in the gestational age at birth categories were compared between upper and lower quartile score infants, there was more with pain at preterm than at term (χ2(3)=44.9, P<0.001) for the Physiological Pain Measures factor, whereas Behavioral Pain Measures frequency was higher at term than at preterm (χ2(3)=8.1, P<0.043). A similar pattern was observed for postmenstrual age at assessment categories: Behavioral Pain Measures (χ2(3)=41.8, P<0.001) Physiological Pain Measures (χ2(3)=46.1, P<0.001). The 2-factor correlated model performed better at explaining the observed variances: (χ2(13)=41.6, P<0.001) compared with rival models.

DISCUSSION

The PAT assesses both Behavioral Pain and Physiological Pain Measures, and these dimensions need to be considered separately when assessing pain in infants in the neonatal intensive care unit. Behavioral item scores may be insufficient for detecting pain in premature infants if used alone.

The newborn infant parasympathetic evaluation index for acute procedural pain assessment in preterm infants

BACKGROUND

Accurate assessments of pain in hospitalized preterm infants present a major challenge in improving the short- and long-term consequences associated with painful experiences. We evaluated the ability of the newborn infant parasympathetic evaluation (NIPE) index to detect acute procedural pain in preterm infants.

METHODS

Different painful and stressful interventions were prospectively observed in preterm infants born at 25 + 0 to 35 + 6 weeks gestation. Pain responses were measured using the composite Premature Infant Pain Profile Revised (PIPP-R) scale, the NIPE index, and skin conductance responses (SCR). Outcome measures were correlations between the NIPE index, the PIPP-R score, and the SCR. Sensitivity/specificity analyses tested the accuracy of the NIPE index and SCR.

RESULTS

Two hundred and fifty-four procedures were recorded in 90 preterm infants. No significant correlation was found between PIPP-R and the NIPE index. PIPP-R and SCR were positively correlated (r = 0.27, P < 0.001), with stronger correlations for painful procedures (r = 0.68, P < 0.001) and especially for skin-breaking procedures (r = 0.82, P < 0.001). The NIPE index and SCR had high sensitivity and high negative predictive values to predict PIPP-R > 10, especially for skin-breaking painful procedures.

CONCLUSIONS

We found no significant correlation between the NIPE index and PIPP-R during routine painful or stressful procedures in preterm infants.

IMPACT

Exposure to repetitive pain can lead to neurodevelopmental sequelae. Behavior-based pain scales have limited clinical utility, especially for preterm infants. New devices for monitoring physiological responses to pain have not been validated sufficiently in preterm infants. This study found that the NIPE index was not significantly correlated to the validated PIPP-R scale during acute procedural pain. Secondary analysis of this study showed that NIPE index and SCRs may help to exclude severe pain in preterm infants. In clinical practice, measurements of physiological parameters should be combined with behavior-based scales for multidimensional pain assessments.

Using sensor-fusion and machine-learning algorithms to assess acute pain in non-verbal infants: a study protocol

INTRODUCTION

Objective pain assessment in non-verbal populations is clinically challenging due to their inability to express their pain via self-report. Repetitive exposures to acute or prolonged pain lead to clinical instability, with long-term behavioural and cognitive sequelae in newborn infants. Strong analgesics are also associated with medical complications, potential neurotoxicity and altered brain development. Pain scores performed by bedside nurses provide subjective, observer-dependent assessments rather than objective data for infant pain management; the required observations are labour intensive, difficult to perform by a nurse who is concurrently performing the procedure and increase the nursing workload. Multimodal pain assessment, using sensor-fusion and machine-learning algorithms, can provide a patient-centred, context-dependent, observer-independent and objective pain measure.

METHODS AND ANALYSIS

In newborns undergoing painful procedures, we use facial electromyography to record facial muscle activity-related infant pain, ECG to examine heart rate (HR) changes and HR variability, electrodermal activity (skin conductance) to measure catecholamine-induced palmar sweating, changes in oxygen saturations and skin perfusion, and electroencephalography using active electrodes to assess brain activity in real time. This multimodal approach has the potential to improve the accuracy of pain assessment in non-verbal infants and may even allow continuous pain monitoring at the bedside. The feasibility of this approach will be evaluated in an observational prospective study of clinically required painful procedures in 60 preterm and term newborns, and infants aged 6 months or less.

ETHICS AND DISSEMINATION

The Institutional Review Board of the Stanford University approved the protocol. Study findings will be published in peer-reviewed journals, presented at scientific meetings, taught via webinars, podcasts and video tutorials, and listed on academic/scientific websites. Future studies will validate and refine this approach using the minimum number of sensors required to assess neonatal/infant pain.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03330496).

Procedural Pain Assessment in Infants Without Analgosedation: Comparison of Newborn Infant Parasympathetic Evaluation and Skin Conductance Activity - A Pilot Study

Objective: New technologies to measure pain responses, such as heart rate variability and skin conductance hold promise in the development of tools that can be reliable and quantifiable of detecting pain. The main objective of this study was to assess the capability of two monitors i.e., Newborn Infant Parasympathetic Evaluation (NIPE) and Skin Conductance Algesimeter for detecting procedural pain in non-anesthetized infants. Materials and Methods: Thirty-three non-anesthetized infants were enrolled to the study. To detect pain caused by heel stick, NIPE, and Skin Conductance monitors and behavioral pain scales were used. Three minutes before and just after heel stick, pain was evaluated by behavioral scales, and simultaneously over the whole period by NIPE and SCA. Results: A statistically significant decrease of NIPE Index and an increase of SCA values were found after the HS procedure. There were no statistically significant differences between the decrease in NIPEi values and the increase in PPS values between subgroups based on pain assessment by behavioral-scale scores. Conclusion: Both NIPE and SCA can be useful for detection of procedural pain and may constitue an additional valuable tool for better handling of pain among patients treated in NICUs. More studies on larger groups of patients are needed.

Effects of two different positions on stress, pain and feeding tolerance of preterm infants during tube feeding

AIMS

This study aims to investigate the effects of semi-elevated right lateral and semi-elevated supine positions on feeding tolerance, stress severity and pain levels among premature infants during tube feeding.

METHODS

This was a randomized cross-over clinical trial. A total of 34 premature infants who were fed via orogastric tube were included in this study. Feeding tolerance was assessed by abdominal circumference measurements and checking gastric residuals; this assessment was single blinded. Physiological values were evaluated before, during and after tube feeding. The stress severity and pain levels of the infants were also evaluated independently by the researchers before, during and after tube feeding. A significance level of .05 was accepted for all statistical analyses.

RESULTS

There were no difference between infants' vital signs, stress and pain scores according to feeding positions before tube feeding (p > .05). By feeding positions, a statistically significant difference was found between infants' vital signs, abdominal circumference and gastric residuals of infants during tube feeding. Pain and stress levels of infants were found to be significantly higher in the semi-elevated supine position during tube feeding (p < .05).

CONCLUSIONS

Use of the semi-elevated right lateral position during tube feeding was found to have a more helpful effect in reducing stress and pain among premature infants when compared with the use of the semi-elevated supine position.

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.

Automated vs. manual pain coding and heart rate estimations based on videos of older adults with and without dementia

Introduction

Technological advances have allowed for the estimation of physiological indicators from video data. FaceReader™ is an automated facial analysis software that has been used widely in studies of facial expressions of emotion and was recently updated to allow for the estimation of heart rate (HR) using remote photoplethysmography (rPPG). We investigated FaceReader™-based heart rate and pain expression estimations in older adults in relation to manual coding by experts.

Methods

Using a video dataset of older adult patients with and without dementia, we assessed the relationship between FaceReader’s™ HR estimations against a well-established Video Magnification (VM) algorithm during baseline and pain conditions. Furthermore, we examined the correspondence between the Facial Action Coding System (FACS)-based pain scores obtained through FaceReader™ and manual coding.

Results

FaceReader’s™ HR estimations were correlated with VM algorithm in baseline and pain conditions. Non-verbal FaceReader™ pain scores and manual coding were also highly correlated despite discrepancies between the FaceReader™ and manual coding in the absolute value of scores based on pain-related facial action coding of the events preceding and following the pain response.

Conclusions

Compared to expert manual FACS coding and optimized VM algorithm, FaceReader™ showed good results in estimating HR values and non-verbal pain scores.

The effect of sleeping position on heart rate variability in newborns

Background

Lower heart rate variability (HRV) in a newborn might represent a risk factor for unfavourable outcome, a longer recovery after illness, and a sudden infant death. Our aim was to determine whether the newborn’s sleeping position is associated with HRV.

Methods

We performed a prospective clinical study in 46 hospitalized cardiorespiratory stable term newborns. During sleeping, we measured the parameters of HRV in four body positions (supine, supine with tilt, prone, prone with tilt).

Results

The TP (total power spectral density) was significantly higher when lying supine in comparison to prone (p = 0,048) and to prone with tilt (p = 0,046). The HF (high frequency of power spectral density) in the supine position without tilt tended to be higher compared to prone without tilt (p > 0,05). The LF (low frequency power) was significantly higher when lying supine compared to prone, both without tilt (p = 0,018). TP and HF showed a positive correlation with gestational but not postmenstrual age (p = 0.044 and p = 0.036, respectively).

Conclusions

In term newborns, sleeping position is associated with HRV. Higher TP and HF were found in the supine position, which might reflect better ANS stability. Gestational age positively correlated with TP and HF power, but only in supine position.

Trial registration

ISRCTN11702082, date of registration: March, 13th, 2020; retrospectively registered.

Use of Mobile Health Apps and Wearable Technology to Assess Changes and Predict Pain During Treatment of Acute Pain in Sickle Cell Disease: Feasibility Study

BACKGROUND

Sickle cell disease (SCD) is an inherited red blood cell disorder affecting millions worldwide, and it results in many potential medical complications throughout the life course. The hallmark of SCD is pain. Many patients experience daily chronic pain as well as intermittent, unpredictable acute vaso-occlusive painful episodes called pain crises. These pain crises often require acute medical care through the day hospital or emergency department. Following presentation, a number of these patients are subsequently admitted with continued efforts of treatment focused on palliative pain control and hydration for management. Mitigating pain crises is challenging for both the patients and their providers, given the perceived unpredictability and subjective nature of pain.

OBJECTIVE

The objective of this study was to show the feasibility of using objective, physiologic measurements obtained from a wearable device during an acute pain crisis to predict patient-reported pain scores (in an app and to nursing staff) using machine learning techniques.

METHODS

For this feasibility study, we enrolled 27 adult patients presenting to the day hospital with acute pain. At the beginning of pain treatment, each participant was given a wearable device (Microsoft Band 2) that collected physiologic measurements. Pain scores from our mobile app, Technology Resources to Understand Pain Assessment in Patients with Pain, and those obtained by nursing staff were both used with wearable signals to complete time stamp matching and feature extraction and selection. Following this, we constructed regression and classification machine learning algorithms to build between-subject pain prediction models.

RESULTS

Patients were monitored for an average of 3.79 (SD 2.23) hours, with an average of 5826 (SD 2667) objective data values per patient. As expected, we found that pain scores and heart rate decreased for most patients during the course of their stay. Using the wearable sensor data and pain scores, we were able to create a regression model to predict subjective pain scores with a root mean square error of 1.430 and correlation between observations and predictions of 0.706. Furthermore, we verified the hypothesis that the regression model outperformed the classification model by comparing the performances of the support vector machines (SVM) and the SVM for regression.

CONCLUSIONS

The Microsoft Band 2 allowed easy collection of objective, physiologic markers during an acute pain crisis in adults with SCD. Features can be extracted from these data signals and matched with pain scores. Machine learning models can then use these features to feasibly predict patient pain scores.

Systematic review and meta-analysis suggest that varying prevalence of non-acute pain in critically ill infants may be due to different definitions

AIM

Our aim was to quantify the prevalence of non-acute pain in critically ill infants and to identify how non-acute pain was described, defined and assessed.

METHODS

This systematic review and meta-analysis used multiple electronic databases to search for papers published in any language to March 2018: 2029 papers were identified, and 68 full texts were screened. Studies reporting the prevalence of non-acute pain in infants younger than 2 years and admitted to critical care units were included. The extracted data included the use of non-acute pain descriptions, definitions and pain assessment tools.

RESULTS

We included 11 studies published between 2002 and 2018 that comprised 1204 infants from Europe, the USA, Canada and India. They were prospective observational (n = 7) and retrospective observational (n = 1) studies and randomised controlled trials (n = 3). The prevalence of non-acute pain was 0%-76% (median 11%). Various pain assessment tools were used, and only two could be pooled. This gave a pooled prevalence of 3.7%-39.8%. A number of different descriptors were used for non-acute pain, and all of these were poorly defined.

CONCLUSION

The prevalence of non-acute pain in infants admitted to critical care units varied considerably. This could have been because all the studies used different definitions of non-acute pain.

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.

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.

Assessment of pain in newborn infants

Hospitalized newborn infants experience pain that can have negative short- and long-term consequences and thus should be prevented and treated. National and international guidelines state that adequate pain management requires valid pain assessment. Nociceptive signals cause a cascade of physical and behavioral reactions that alone or in combination can be observed and used to assess the presence and intensity of pain. Units that are caring for newborn infants must adopt sufficient pain assessment tools to cover the gestational ages and pain types that occurs in their setting. Pain assessment should be performed on a regular basis and any detection of pain should be acted on. Future research should focus on developing and validating pain assessment tools for specific situations.

Newborn infant parasympathetic evaluation (NIPE) as a predictor of hemodynamic response in children younger than 2 years under general anesthesia: an observational pilot study

Background

It is still unknown whether newborn infant parasympathetic evaluation (NIPE), based on heart rate variability (HRV) as a reflection of parasympathetic nerve tone, can predict the hemodynamic response to a nociception stimulus in children less than 2 years old.

Methods

Fifty-five children undergoing elective surgery were analyzed in this prospective observational study. Noninvasive mean blood pressure (MBP), heart rate (HR) and NIPE values were recorded just before and 1 min after general anesthesia with endotracheal intubation as well as skin incision. The predictive performance of NIPE was evaluated by receiver-operating characteristic (ROC) curve analysis. A significant hemodynamic response was defined by a > 20% increase in HR and/or MBP.

Results

Endotracheal intubation and skin incision caused HR increases of 22.2% (95% confidence interval [CI] 17.5–26.9%) and 3.8% (2.1–5.5%), MBP increases of 18.2% (12.0–24.4%) and 10.6% (7.7–13.4%), and conversely, NIPE decreases of 9.9% (5.3–14.4%) and 5.6% (2.1–9.1%), respectively (all P < 0.01 vs. pre-event value). Positive hemodynamic responses were observed in 32 patients (62.7%) during tracheal intubation and 13 patients (23.6%) during skin incision. The area under the ROC curve values for the ability of NIPE to predict positive hemodynamic responses at endotracheal intubation and skin incision were 0.65 (0.50–0.78) and 0.58 (0.44–0.71), respectively.

Conclusions

NIPE reflected nociceptive events as well as anesthestic induction in children less than 2 years undergoing general anaesthetia. Nevertheless, NIPE may not serve as a sensitive and specific predictor to changes in hemodynamics.

Trial registration

This study was registered on May 3, 2018 in the Chinese Clinical Trail Registry; the registration number is (ChiCTR1800015973).

The heart rate variability-derived Newborn Infant Parasympathetic Evaluation (NIPE™) Index in pediatric surgical patients from 0 to 2 years under sevoflurane anesthesia-A prospective observational pilot study

BACKGROUND

The heart rate variability-derived Newborn Infant Parasympathetic Evaluation (NIPE™) Index is a continuous noninvasive tool to assess pain and discomfort in infants <2 years. Initial studies focused on pain monitoring in the neonatal intensive care unit environment.

AIMS

The aim of this study was to investigate the performance of the NIPE in infants under sevoflurane anesthesia. The primary objective of this study was to compare the NIPE and heart rate as tools to help recognize the need for additional opioid drugs. Secondary objectives were the course of the NIPE and heart rate around specific standardized noxious procedural mile-stones.

METHODS

NIPE and heart rate values recorded during a 120 seconds interval before the anesthetist's decision to administer additional opioid due to the perceived insufficient antinociception and during a 120 seconds interval after drug administration were analyzed by means of a repeated measures ANOVA. The same analyses were performed for datasets around per protocol administration of morphine for postoperative analgesia, performance of a caudal block and surgical incision.

RESULTS

In patients with a NIPE value <50, an additional opioid drug administration resulted in a rise of NIPE values, reaching a maximum increase of 5.1 (95% CI: 0.22-9.99) units 120 seconds after drug administration (P = 0.041). There was no evidence of a change in heart rate during these two 120 seconds periods. Per protocol administration of morphine, caudal block, and surgical incision did not result in changes of the NIPE, which was around 65 units on these occasions, and heart rate.

CONCLUSION

In infants anesthetized with sevoflurane, NIPE values <50 might be indicative of insufficient antinociception. The results of this observational pilot study might suggest that the NIPE could be a better measure of the nociception/antinociception balance than heart rate.

Facilitated tucking during early neonatologist-performed echocardiography in very preterm neonates

AIM

To assess the effect of facilitated tucking (FT), a nonpharmacologic nursing intervention, on echocardiographic parameters and infant comfort collected prospectively during neonatologist-performed echocardiography.

METHODS

Echocardiography was performed twice, in standard conditions and with FT; the order was randomised by computer. Echocardiography provided data on pulmonary artery flow and pressure, right and left ventricular function, and persistent ductus arteriosus. Comfort was assessed by a behavioural scale of pain, variations in heart rate (HR) and SpO₂ , and a newborn infant parasympathetic evaluation index based on the high-frequency variability in HR.

RESULTS

Fifty newborns, with mean gestational age of 28 [26.6-29.0] weeks and mean birthweight of 950 [780-1190] g, were studied at a postnatal age of 13 [9-27] hours. FT was associated with longer acceleration time/right ventricular ejection time in the main pulmonary artery (p = 0.006), reduced averaged HR variations (p = 0.03) and lower pain scores (p < 0.001). The other haemodynamic parameters and the parasympathetic index were not influenced by FT.

CONCLUSION

Echocardiography performed soon after birth in very premature neonates may generate mild discomfort. FT during echocardiography is associated with lower pulmonary artery pressures and improves infant's comfort during this examination.

Multi-modal pain assessment: are near-infrared spectroscopy, skin conductance, salivary cortisol, physiologic parameters, and Neonatal Facial Coding System interrelated during venepuncture in healthy, term neonates?

Background

Improving pain and stress assessments in neonates remains important in preventing the short- and long-term consequences. We aimed to identify the relationships between different pain assessment parameters by simultaneously measuring changes in cortical, autonomic, hormonal, physiological, and behavioral evoked responses to venepuncture in healthy, full-term neonates.

Methods

This observational, prospective study (ancillary to the ACTISUCROSE trial) included 113 healthy, 3-day old, full-term neonates who underwent venepuncture for systematic neonatal screening, from July to October 2013, in a tertiary-level maternity ward of a university hospital. During venepuncture, we simultaneously measured the cortical single-channel near-infrared spectroscopy (NIRS) signals, foot skin conductance, salivary cortisol, physiological responses, and behavioral (Neonatal Facial Coding System [NFCS]) evoked responses.

Results

Regarding the NIRS analysis, the highest correlation was between the NFCS at venepuncture and the change in NIRS integrated values of total hemoglobin (r=0.41, P<0.001) or oxygenated hemoglobin (r=0.27, P<0.001). The NFCS at venepuncture was moderately positively correlated with changes in salivary cortisol (r=0.42, P<0.001) and skin conductance (r=0.29, P<0.001). Salivary cortisol and skin conductance changes were not correlated; the latter parameters were not correlated with heart rate, respiratory rate, or SpO2.

Conclusion

During venepuncture, NFCS was mildly or moderately correlated with salivary cortisol, skin conductance, and cortical NIRS changes.

Evaluation of prolonged pain in preterm infants with pneumothorax using heart rate variability analysis and EDIN (Échelle Douleur Inconfort Nouveau-Né, neonatal pain and discomfort scale) scores

Purpose

The EDIN scale (Échelle Douleur Inconfort Nouveau-Né, neonatal pain and discomfort scale) and heart rate variability has been used for the evaluation of prolonged pain. The aim of our study was to assess the value of the newborn infant parasympathetic evaluation (NIPE) index and EDIN scale for the evaluation of prolonged pain in preterm infants with chest tube placement due to pneumothorax.

Methods

This prospective observational study assessed prolonged pain in preterm infants with a gestational age between 33 and 35 weeks undergoing installation of chest tubes. Prolonged pain was assessed using the EDIN scale and NIPE index.

Results

There was a significant correlation between the EDIN scale and NIPE index (r=-0.590, P=0.003). Prolonged pain is significantly more severe in the first 6 hours following chest tube installation (NIPE index: 60 [50–86] vs. 68 [45–89], P<0.002; EDIN score: 8 [7–11] vs. 6 [4–8], P<0.001).

Conclusion

Prolonged pain can be accurately assessed with the EDIN scale and NIPE index. However, evaluation with the EDIN scale is time-consuming. The NIPE index can provide instantaneous assessment of prolonged and continuous pain.

Sample Size Determination for Evaluation of Time Domain Heart Rate Variability Indices in Canine Lameness

Heart rate variability (HRV) is a physiologic phenomenon that occurs due to changing autonomic tone resulting in variable RR intervals. A reduction in HRV is used as an index of pain in neonatal human patients. Objective measures of pain would be valuable in the evaluation of canine patients and assessment of response to pain management strategies. We hypothesized that dogs with diseases associated with discomfort (osteoarthritis and bone neoplasia) would have reduced HRV compared with normal, healthy dogs. The aim of the study was to calculate the sample size necessary to investigate this hypothesis. Seventeen dogs from the Ryan Veterinary Hospital of the University of Pennsylvania patient population or owned by Ryan Veterinary Hospital of the University of Pennsylvania staff were enrolled in this single-blind, prospective pilot study. A 30 min electrocardiogram (ECG) was obtained from each dog using an ambulatory electrocardiographic monitor. All ECGs were obtained between 10 a.m. and 2 p.m. ECGs were analyzed and time-domain HRV indices computed. Sample size calculations suggest that 207 dogs would be necessary to ascertain if HRV is reduced in dogs experiencing discomfort or pain (50 in the arthritis group, 79 in the bone cancer group, and 78 in the control group).

A Review of Automated Pain Assessment in Infants: Features, Classification Tasks, and Databases

Bedside caregivers assess infants' pain at constant intervals by observing specific behavioral and physiological signs of pain. This standard has two main limitations. The first limitation is the intermittent assessment of pain, which might lead to missing pain when the infants are left unattended. Second, it is inconsistent since it depends on the observer's subjective judgment and differs between observers. Intermittent and inconsistent assessment can induce poor treatment and, therefore, cause serious long-term consequences. To mitigate these limitations, the current standard can be augmented by an automated system that monitors infants continuously and provides quantitative and consistent assessment of pain. Several automated methods have been introduced to assess infants' pain automatically based on analysis of behavioral or physiological pain indicators. This paper comprehensively reviews the automated approaches (i.e., approaches to feature extraction) for analyzing infants' pain and the current efforts in automatic pain recognition. In addition, it reviews the databases available to the research community and discusses the current limitations of the automated pain assessment.