Analysis of acute pain scores and skin conductance measurements in infants

Current Evidence for Biological Biomarkers and Mechanisms Underlying Acute to Chronic Pain Transition across the Pediatric Age Spectrum

Chronic pain is highly prevalent in the pediatric population. Many factors are involved in the transition from acute to chronic pain. Currently, there are conceptual models proposed, but they lack a mechanistically sound integrated theory considering the stages of child development. Objective biomarkers are critically needed for the diagnosis, risk stratification, and prognosis of the pathological stages of pain chronification. In this article, we summarize the current evidence on mechanisms and biomarkers of acute to chronic pain transitions in infants and children through the developmental lens. The goal is to identify gaps and outline future directions for basic and clinical research toward a developmentally informed theory of pain chronification in the pediatric population. At the outset, the importance of objective biomarkers for chronification of pain in children is outlined, followed by a summary of the current evidence on the mechanisms of acute to chronic pain transition in adults, in order to contrast with the developmental mechanisms of pain chronification in the pediatric population. Evidence is presented to show that chronic pain may have its origin from insults early in life, which prime the child for the development of chronic pain in later life. Furthermore, available genetic, epigenetic, psychophysical, electrophysiological, neuroimaging, neuroimmune, and sex mechanisms are described in infants and older children. In conclusion, future directions are discussed with a focus on research gaps, translational and clinical implications. Utilization of developmental mechanisms framework to inform clinical decision-making and strategies for prevention and management of acute to chronic pain transitions in children, is highlighted.

Correlation between skin conductance measurements and subjective pain scales in children after otolaryngological procedures

Introduction

Pain assessment in children is crucial in managing postoperative analgesia; it is therefore necessary to determine the most accurate tool for assessing pain in children. The aim of this study was to evaluate the correlation between skin conductance measurements and self-reporting pain scales in children after otolaryngology procedures.

Materials and methods

Thirty-three children (N=33) were assessed for eligibility for the research. Postoperative pain was assessed using the Visual Analogue Scale; the Wong-Baker Faces Pain Rating Scale; the Face, Legs, Activity, Cry, and Consolability scale; and a skin conductance algesimeter. The postoperative pain was measured 1 and 2 hours after the surgery.

Results

There was no statistically significant correlation between self-reported pain scores and the skin conductance fluctuations in the children studied, regardless of gender or age. A statistically significant correlation was found between the existing subjective pain scales in children.

Conclusions

The skin conductance measurements do not provide an additional reliable tool for assessing pain in patients after otolaryngological procedures. The existing self-reported pain scales are sufficient to assess postoperative pain in children.

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.

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.

The validity of skin conductance for assessing acute pain in mechanically ventilated infants: A cross-sectional observational study

BACKGROUND

Assessing pain in mechanically ventilated infants is challenging. The assessment of skin conductance (SC) is based on the sympathetic nervous system response to stress. This study purpose was to evaluate the validity of SC for assessing pain in mechanically ventilated infants.

METHODS

A prospective cross-sectional observational design was used to study SC and its relation to: the category of procedure (i.e., painful or non-painful); the phase of procedure (i.e., before, during and after), and referent pain measurements (i.e., Premature Infant Pain Profile-Revised (PIPP-R) and Neonatal Facial Coding System (NFCS)). Eligible infants were those up to 12 months of age, in intensive care units, who were mechanically ventilated, and required painful and non-painful procedures.

RESULTS

From October 2017 to November 2018, 130 eligible infants were identified, and 55 infants were studied. SC (number of waves per second) during painful procedures (median 0.27, interquartile range 0.2-0.4) was statistically significantly higher than those during non-painful procedures (0, 0-0.09). SC during painful procedures was statistically significantly higher than those before (0, 0-0.07) and after painful procedures (0, 0-0.07). SC showed moderate statistically significant positive correlations with PIPP-R (Spearman's rho = 0.4-0.62) and the four-item NFCS (Spearman's rho = 0.31-0.67) before, during and after painful or non-painful procedures respectively. SC had excellent performance (area under the receiver operator curve = 0.979) with excellent sensitivity (92.31%), specificity (95.42%) and negative predictive value (99.21%) but only sufficient positive predictive value (66.67%) when used to discriminate moderate-to-severe pain.

CONCLUSIONS

SC showed good validity for assessing pain in critically ill infants requiring mechanical ventilation.

SIGNIFICANCE OF THE STUDY

Pain assessment in mechanically ventilated infants is challenging. In this study, the validity of skin conductance (SC) for pain assessment is evaluated in the same population of infants during painful and nonpainful procedures. SC showed good validity for assessing acute pain in relation to category of procedure, phase of procedure, and referent pain measurements. SC is a promising method, especially with other pain assessment methods and other determinants of pain, in a multimodal pain assessment approach to understand the complexity of pain in mechanically ventilated infants.

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.

Painapple®. Validation and evaluation of an electronic application for the management of acute pain in pediatric patients

INTRODUCTION

The digital version of the assessment scales recommended for the pediatric patient could contribute to its improvement and to implement the quality indicators described for the management of acute pain.

MATERIAL AND METHODS

Psychometric validation (validity and reliability) of pain assessment and treatment side effects scales incorporated in the electronic application PainAPPle. For this, both formats (paper and electronic) of all the scales were applied in two measurements with 30minutes of difference in 44 patients from 4 to 18years of the Acute Pain Unit in the immediate postoperative period. In addition, the data collected by PainAPPle was evaluated by retrospectively applying the quality indicators described for the management of acute postoperative pain.

RESULTS

Reliability was studied analyzing the high correlation (Spearman greater than 0.5, P<.001) that we obtained for the values of each scale in two moments with 30minutes of difference, in the same patients. For validity, the high correlation (Spearman greater than 0.5, P<.001) between the values of the paper scales (gold rule) and PainAPPle at both minute 0 and 30 was analyzed. Concordance obtained taking into account the cut-off point of the scales that would force a treatment were also statistically significant (P<.005).

CONCLUSIONS

PainAPPle is a validated instrument for the management of acute pain in pediatric patients. The collected data allow to apply the quality indicators described for the management of acute postoperative pain.

The Validity of Skin Conductance For Assessing Acute Pain in Infants: A Scoping Review

OBJECTIVES

Measuring pain in infants is important but challenging, as there is no "gold standard." The measurement of skin conductance (SC) is considered to be a measure of stress and as a surrogate indicator of pain. The objectives of this study were to identify the extent of research conducted and to synthesize the validity evidence of SC for assessing acute pain in infants.

METHODS

The Arksey and O'Malley framework for scoping reviews was followed, and 9 electronic databases were searched. Data were analyzed thematically and presented descriptively including the following main categories: study information/details, sampling information, characteristics of participants and settings, SC outcome measures, and validity evidence.

RESULTS

Twenty-eight studies with 1061 infants were included, including 23 cross-sectional observation studies and 5 interventional studies. The most studied infants were those with mild severity of illness (n=13) or healthy infants (n=12). The validity evidence of SC was tested in relation to referent pain measures (13 variables), stimuli (13 variables), age (2 variables), and other contextual variables (11 variables). SC was not significantly correlated with vital signs, except for heart rate in 2 of the 8 studies. SC was significantly correlated with the unidimensional behavioral pain assessment scales and crying time rather than with multidimensional measurements. Fourteen of 15 studies (93.3%) showed that SC increased significantly during painful procedures.

CONCLUSIONS

Inconsistent findings on validity of SC exist. Future research should aim to identify the diagnostic test accuracy of SC compared with well-accepted referent pain measures in infants, study the validity evidence of SC in critically ill infants, and utilize rigorous research design and transparent reporting.

Prenatal opioid exposure heightens sympathetic arousal and facial expressions of pain/distress in term neonates at 24-48 hours post birth

Purpose: The rising issue of opioid use during pregnancy poses an increased risk of fetal exposure to opioids in-utero and the development of neonatal abstinence syndrome (NAS). The cessation of exposure to opioids upon birth causes elevated levels of norepinephrine in the circulation enhancing sympathetic arousal. Skin conductance (SC) detects sympathetic-mediated sweating while the Neonatal Facial Coding System (NFCS) depicts facial expressions of stress and pain. We hypothesize that there will be a direct correlation between SC and NFCS scores, such that neonates with prenatal opioid exposure will have higher SC and facial responses to pain/stress as compared with healthy neonates without prenatal opioid exposure.Objective: This study evaluates the utility of SC and the NFCS in the objective assessment of early postnatal pain response in opioid-exposed and non-opioid exposed neonates.Methods: This prospective, single-center, pilot study enrolled opioid-exposed term neonates (>37 weeks) and healthy controls. Subjects were observed within 24-48 hours post-birth (and prior to opioid withdrawal) for pain at baseline, during, and post-heel lance/squeeze (HLS) with simultaneously measured SC and videotaped facial expressions. SC data included electro-dermal responses over time (EDR/second) and the average amplitude of responses (mean of peaks [MP]). Video data were scored using the NFCS by two trained coders with inter-rater agreement >85%.Results: SC and NFCS scores were significantly associated with both groups. The opioid-exposed neonates had significantly higher skin conductance indices, EDR/sec for the HLS phase, and MP for HLS and post phases as compared with controls (p < .05). Opioid-exposed neonates demonstrated higher NFCS at baseline (p = .003).Conclusions: Prenatal opioid exposure was associated with heightened sympathetic arousal during both pain and recovery phases and higher facial expressions of pain/distress at baseline only. A multimodal system of assessment may be useful in understanding the complexity and severity of opioid withdrawal associated with NAS.

Postoperative Pain and Analgesia in Children Undergoing Palatal Surgery: A Retrospective Chart Review

PURPOSE

Pediatric patients undergoing palatal surgery may experience significant postoperative pain. Undertreatment of acute postoperative pain may impact postoperative bleeding and recovery. The primary objectives of this study were to evaluate the severity of acute postoperative pain scores, analgesia management, and discharge times after palatal surgery.

DESIGN AND METHODS

A retrospective chart review was performed for all patients aged <18 years, born with cleft palate who underwent palatal surgery over a 1-year period. The primary outcome variable was the highest pain score recorded by the nursing staff at various time frames postoperatively.

FINDINGS

Overall, the infant/toddler group demonstrated higher postoperative pain scores throughout the first 24 hours (1- to 6-hour period, P = .015). The duration of hospital stay was significantly greater in the infant/toddler age group (P < .001).

CONCLUSION

The results of our study indicate that frequent pain monitoring, multimodal approach, and "round-the-clock" analgesics may be warranted in this vulnerable patient population.

Skin conductance at baseline and postheel lance reflects sympathetic activation in neonatal opiate withdrawal

AIM

Skin conductance (SC) provides an objective measure of autonomic system regulation through sympathetic-mediated filling of sweat glands. This study aimed to test the utility of SC to detect sympathetic activation in neonatal abstinence syndrome (NAS).

METHODS

Fourteen term (mean, SE: 38.8 ± 0.35 weeks gestational age) neonates with chronic prenatal opiate exposure were enrolled. SC (peaks/seconds and mean of peaks) was measured at baseline, during heel lance/squeeze (HLS) and recovery from HLS at 24-48 (mean 38) hours of life prior to treatment for NAS. Blinded coders with established reliability assessed neonates using the Modified Finnegan Neonatal Scoring System (MFNSS). Nonparametric tests were used to determine group differences, phase differences from baseline to HLS and HLS to recovery, and associations between MFNSS and SC measures.

RESULTS

Neonates that would later require morphine treatment for NAS (n = 6) had higher baseline SC mean of peaks than those that did not require treatment (n = 8) (p < 0.05). Moreover, there were unique phase differences between groups and SC positively correlated with MFNSS (p < 0.05).

CONCLUSION

SC provides early identification of NAS severity. However, a larger sample is needed to determine sensitivity and specificity of SC for early identification of NAS and treatment effectiveness.

Bayesian estimation on diagnostic performance of Face, Legs, Activity, Cry, and Consolability and Neonatal Infant Pain Scale for infant pain assessment in the absence of a gold standard

BACKGROUND

Nonverbal pediatric patients such as infants are unable to describe their pain, which leads to the lack of a gold standard scale for their pain assessment. The aim of this study was to estimate the diagnostic performance of Face, Legs, Activity, Cry, and Consolability (FLACC) scale and Neonatal Infant Pain Scale (NIPS) for infants' pain in the absence of a gold standard.

METHODS

This prospective observational study recruited 202 postoperative infants, aged <12 months. Postoperative pain intensity was evaluated using FLACC and NIPS scales. The diagnostic performance of these two scales was to estimate using a Bayesian latent class model with conditional dependence. McNemar's test was applied to test whether NIPS and FLACC tests differ from each other.

RESULTS

Under a combined model with conditional dependence, the median posterior sensitivity and specificity of the FLACC were 89.94% (95% CI: 78.48-96.83%) and 87.82% (95% CI: 78.6-95.23%), respectively. The sensitivity and specificity of the NIPS were 85.94% (95% CI: 72.15-95.6%) and 92.61% (84.05-97.52%), respectively. McNemar's test demonstrated no significant difference between FLACC and NIPS in either sensitivity or specificity.

CONCLUSION

Both the FLACC and NIPS have excellent sensitivity and specificity for pain assessment in infants. The comparison test showed that the FLACC scale was no different to the NIPS scale in sensitivity and specificity.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.