Skin conductance and the stress response from heel stick in preterm infants

Multiple Attempts of Peripheral Intravenous Catheter Insertion in a Preterm Infant Provoke Toxic Stress: A Case Report

Premature infants admitted to the NICU often require intravenous (IV) therapy. Peripheral intravenous catheter (PIVC) insertion is a common painful/stressful/invasive procedure. Repeated exposure to stressors produces toxic stress: a prolonged, frequent activation of the body's stress response that occurs when buffering relationships, that is, mother/supportive adult, are absent. This article presents an exemplar case study of a PIVC insertion to describe toxic stress responses a premature infant experienced during the procedure. The infant was admitted for extreme prematurity and respiratory failure. Twenty-nine days later, the infant developed possible necrotizing enterocolitis that necessitated cessation of enteral feedings, gastric decompression, IV administration of fluids, parenteral nutrients, and antibiotics. The PIVC insertion procedure was monitored and observed. The infant showed physiologic dysregulation, including bradycardia, tachycardia, oxygen desaturation, and high skin conductance responses, resulting from the stress exposure and insufficient nonpharmacologic/pharmacologic stress interventions. Education and practice change are needed to promote pain/stress management.

Toddlers' affective responses to sociomoral scenes: Insights from physiological measures

A growing literature suggests that preverbal infants are sensitive to sociomoral scenes and prefer prosocial agents over antisocial agents. It remains unclear, however, whether and how emotional processes are implicated in infants' responses to prosocial/antisocial actions. Although a recent study found that infants and toddlers showed more positive facial expressions after viewing helping (vs. hindering) events, these findings were based on naïve coder ratings of facial activity; furthermore, effect sizes were small. The current studies examined 18- and 24-month-old toddlers' real-time reactivity to helping and hindering interactions using three physiological measures of emotion-related processes. At 18 months, activity in facial musculature involved in smiling/frowning was explored via facial electromyography (EMG). At 24 months, stress (sweat) was explored via electrodermal activity (EDA). At both ages, arousal was explored via pupillometry. Behaviorally, infants showed no preferences for the helper over the hinderer across age groups. EMG analyses revealed that 18-month-olds showed higher corrugator activity (more frowning) during hindering (vs. helping) actions, followed by lower corrugator activity (less frowning) after hindering (vs. helping) actions finished. These findings suggest that antisocial actions elicited negativity, perhaps followed by brief disengagement. EDA analyses revealed no significant event-related differences. Pupillometry analyses revealed that both 18- and 24-month-olds' pupils were smaller after viewing hindering (vs. helping), replicating recent evidence with 5-month-olds and suggesting that toddlers also show less arousal following hindering than following helping. Together, these results provide new evidence with respect to whether and how arousal/affective processes are involved when infants process sociomoral scenarios.

Autonomic measures identify stress, pain, and instability associated with retinopathy of prematurity ophthalmologic examinations

BACKGROUND

Retinopathy of prematurity (ROP) ophthalmologic examinations cause stress and pain. Infants' stress and pain can be measured non-invasively using skin conductance (SC) and high frequency heart rate variability (HF-HRV), reflecting sympathetic-mediated sweating and parasympathetic activity, respectively.

OBJECTIVES

To test the utility of SC to detect sympathetic activation during ROP examination, and the contribution of HF-HRV to predict stability post-examination.

METHODS

In this prospective, single center study, we measured SC continuously pre-, during, and post-examination, and HRV at 24 h pre-ROP examination. Clinical data included stability [apneas, bradycardias, and desaturations (A/B/Ds)], and interventions post-examination.

RESULTS

SC increased 56% above baseline during ROP examination (p = 0.001) and remained elevated post-examination (p = 0.02). Post-hoc analysis showed higher illness acuity, represented by need for respiratory support, was associated with lower HF-HRV at 24 h pre-ROP examination (p = 0.001). Linear regression indicated lower HF-HRV at 24 h pre-examination contributed to the need for higher intervention (i.e., stimulation to breathe, oxygen support) particularly among infants with higher illness acuity [F(1, 15) = 5.05, p = 0.04; β = -1.33, p = 0.04].

CONCLUSION

ROP examination induced a 2-fold increase in sympathetic activation which remained above baseline in recovery. Also, we propose that the low parasympathetic tone associated with autonomic imbalance contributes to instability and need for higher intervention to assure stabilization with A/B/D events. Our findings provide insight into the underestimation of adverse events associated with ROP examination and identification of infants who may be more vulnerable to potential sequelae following ROP examinations.

Monitoring of analgesia level during general anesthesia in children

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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.

Combining Electrodermal Activity With the Peak-Pain Time to Quantify Three Temporal Regions of Pain Experience

Background

Self-reported pain levels, while easily measured, are often not reliable for quantifying pain. More objective methods are needed that supplement self-report without adding undue burden or cost to a study. Methods that integrate multiple measures, such as combining self-report with physiology in a structured and specific-to-pain protocol may improve measures.

Method

We propose and study a novel measure that combines the timing of the peak pain measured by an electronic visual-analog-scale (eVAS) with continuously-measured changes in electrodermal activity (EDA), a physiological measure quantifying sympathetic nervous system activity that is easily recorded with a skin-surface sensor. The new pain measure isolates and specifically quantifies three temporal regions of dynamic pain experience: I. Anticipation preceding the onset of a pain stimulus, II. Response rising to the level of peak pain, and III. Recovery from the peak pain level. We evaluate the measure across two pain models (cold pressor, capsaicin), and four types of treatments (none, A=pregabalin, B=oxycodone, C=placebo). Each of 24 patients made four visits within 8 weeks, for 96 visits total: A training visit (TV), followed by three visits double-blind presenting A, B, or C (randomized order). Within each visit, a participant experienced the cold pressor, followed by an hour of rest during which one of the four treatments was provided, followed by a repeat of the cold pressor, followed by capsaicin.

Results

The novel method successfully discriminates the pain reduction effects of the four treatments across both pain models, confirming maximal pain for no-treatment, mild pain reduction for placebo, and the most pain reduction with analgesics. The new measure maintains significant discrimination across the test conditions both within a single-day's visit (for relative pain relief within a visit) and across repeated visits spanning weeks, reducing different-day-physiology affects, and providing better discriminability than using self-reported eVAS.

Conclusion

The new method combines the subjectively-identified time of peak pain with capturing continuous physiological data to quantify the sympathetic nervous system response during a dynamic pain experience. The method accurately discriminates, for both pain models, the reduction of pain with clinically effective analgesics.

The Effect of Daylight Illumination in Nursing Buildings on Reading Comfort of Elderly Persons

Reading is one of the popular activities among elderly persons. A reasonable level of daylight illumination can ensure the visual comfort of reading for elderly persons. State arousal level and subjective comfort report are important parameters reflecting the effect of daylight illumination on visual comfort of reading in elderly persons. In this study, daylight illumination measurements were conducted in a nursing institution of Shenyang, China. Moreover, the methods of electrodermal activity (EDA) physiological index measurement and questionnaire scoring were used to compare and analyze the state arousal level and visual comfort of elderly persons under different illumination conditions. The results show that when elderly persons were involved in their daily reading activity, the acceptable daylight illumination range was between 300 and 1000 lx. When the daylight illumination was between 600 and 800 lx, the state arousal level and visual comfort was high; when it was 700 lx, the state arousal level and visual comfort was the highest. Although 500 and 900 lx both indicated neutral illumination, the evaluations were more consistent at 500 lx than at 900 lx. At 300, 400, and 1000 lx, visual comfort was poor and the state arousal level was low. At 300 lx, visual comfort was the worst and the state arousal level was the lowest. This study provides a reliable reference for architects to design the daylight conditions of the living spaces of the elderly.

Measurement of Cumulative Preterm Neonatal and Maternal Stressors During Neonatal Intensive Care Unit Admission

OBJECTIVES

By nature, the neonatal intensive care unit (NICU) environment is stressful for both infants and mothers. This study aimed to explore and quantify the severity of early life stressors in premature infants admitted to the NICU and evaluate the effect of cumulative neonatal stressors on maternal mental health.

METHODS

This cross-sectional study included 100 preterm infants admitted to the NICU for at least 10 days. Daily experiences with painful/stressful procedures for 10 days were determined using the Neonatal Infant Stressor Scale. The included mothers were assessed for their psychological well-being 1 week after NICU admission using the Parental Stressor Scale: NICU and Edinburgh Postnatal Depression Scale.

RESULTS

During the first 10 days of NICU admission, preterm infants experienced an average of 350.76 ± 84.43 acute procedures and an average of 44.84 ± 11.12 cumulative hours of chronic events, with the highest scores recorded on first 3 days of admission. Although intravenous flushing for patency was the most frequent acute procedure, blood gas sampling was the most painful. Forty-five percent of the mothers showed significant depressive symptoms, with the maternal role alteration reported as the most stressful experience, especially for young and new mothers (p < .001). The cumulative stressors experienced by infants were significantly associated with elevated maternal perception of psychological maladjustment (p < .001).

CONCLUSION

This study confirmed that the NICU environment is stressful for both infants and mothers, with the total cumulative stressors experienced by preemies in the NICU having an negative impact on maternal mental health.

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.

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 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.

Clinical care of neonates undergoing opioid withdrawal in the immediate postpartum period

As the opioid epidemic escalates in westernized countries around the world, chronic opioid use during pregnancy has become a growing public health issue. There are increasing concerns that chronic maternal opioid use might adversely affect the developing fetal brain. Furthermore, the sudden discontinuation of the trans-placental opioid supply at birth puts newborns at acute risk for neonatal opioid withdrawal syndrome (NOWS). NOWS is a multi-system disorder that has been identified in approximately 50-80% of neonates exposed to opioids due to chronic maternal use. Clinically, NOWS affects the central and autonomic nervous systems as well as the gastrointestinal and respiratory tracts. The clinical features of NOWS include hyperirritability, high-pitched crying, restlessness, tremors, poor sleep, agitation, seizures, sweating, fever, poor feeding, regurgitation, diarrhea, and tachypnea. NOWS is currently diagnosed using a clinical scoring tool followed by toxicological confirmation of the presence of opioids in meconium or tissue specimens. The first-line treatments for NOWS are non-pharmacologic comfort measures. If these measures fail, neonates may be treated with opioids and/or sedatives. Since the severity of NOWS can be highly variable, it is quite difficult to predict which opioid-exposed neonates will require pharmacotherapy and prolonged hospitalization. Factors associated with maternal polysubstance use, including the use of illicit substances and tobacco, have been associated with the increased severity and duration of NOWS. Since neonates with NOWS are at increased risk for long-term adverse neurodevelopmental outcomes, ongoing monitoring beyond the neonatal period is essential.

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.

Atypical Emotional Electrodermal Activity in Toddlers with Autism Spectrum Disorder

Past studies in autism spectrum disorder (ASD) indicate atypical peripheral physiological arousal. However, the conditions under which these atypicalities arise and their link with behavioral emotional expressions and core ASD symptoms remain uncertain. Given the importance of physiological arousal in affective, learning, and cognitive processes, the current study examined changes in skin conductance level (ΔSCL) in 41 toddlers with ASD (mean age: 22.7 months, SD: 2.9) and 32 age-matched toddlers with typical development (TD) (mean age: 21.6 months, SD: 3.6) in response to probes designed to induce anger, joy, and fear emotions. The magnitude of ΔSCL was comparable during anger (P = 0.206, d = 0.30) and joy (P = 0.996, d = 0.01) conditions, but significantly lower during the fear condition (P = 0.001, d = 0.83) in toddlers with ASD compared to TD peers. In the combined samples, ΔSCL positively correlated with intensity of behavioral emotional expressivity during the anger (r[71] = 0.36, P = 0.002) and fear (r[68] = 0.32, P = 0.007) conditions, but not in the joy (r[69] = -0.15, P = 0.226) condition. Finally, ΔSCL did not associate with autism symptom severity in any emotion-eliciting condition in the ASD group. Toddlers with ASD displayed attenuated ΔSCL to situations aimed at eliciting fear, which may forecast the emergence of highly prevalent internalizing and externalizing problems in this population. The study putatively identifies ΔSCL as a dimension not associated with severity of autism but with behavioral responses in negatively emotionally challenging events and provides support for the feasibility, validity, and incipient utility of examining ΔSCL in response to emotional challenges in very young children. LAY SUMMARY: Physiological arousal was measured in toddlers with autism exposed to frustrating, pleasant, and threatening tasks. Compared to typically developing peers, toddlers with autism showed comparable arousal responses to frustrating and pleasant events, but lower responses to threatening events. Importantly, physiological arousal and behavioral expressions were aligned during frustrating and threatening events, inviting exploration of physiological arousal to measure responses to emotional challenges. Furthermore, this study advances the understanding of precursors to emotional and behavioral problems common in older children with autism. Autism Res 2020, 13: 1476-1488. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.

The relationship between sleep and autonomic health

Objective: To examine the relationship between sleep and resting autonomic nervous system (ANS) functioning in college students. Participants: Participants were 141 undergraduate students (52 males) recruited from a large southeastern university during September-October 2017. Methods: Participants completed self-report inventories (demographic and sleep characteristics). Resting state skin conductance (SC) and heart rate variability (HRV) were measured in a laboratory setting for ANS functioning. Results: SC was positively associated with sleep quality (p = 0.027), sleep latency (p = 0.040), and use of sleep medication (p < 0.001). Analyses yielded a negative association between the standard deviation of the normal-normal interval of heart beats (SDNN) and the self-reported amount of time to fall asleep each night (p = 0.041). Sleep efficiency was negatively correlated with low frequency HRV (p = 0.002). Conclusions: Sleep components are associated with resting ANS activity, and targeted interventions focused on improved ANS functioning may benefit sleep quality in college students.

Pain assessment during eye examination for retinopathy of prematurity screening: Skin conductance versus PIPP-R

AIM

To assess changes in skin conductance during retinopathy of prematurity screening and to study the correlation between the skin conductance and a validated pain scale.

METHODS

Prospective observational study. Fifty-three eye examinations were performed in 32 preterm infant candidates for retinopathy of prematurity screening. Outcome measures were changes in Premature Infant Pain Profile-Revised (PIPP-R) scale and number of skin conductance fluctuations.

RESULTS

There was a significant increase from baseline in the number of skin conductance fluctuations and PIPP-R during the procedure. The maximum value of number of skin conductance fluctuations was 0.64 ± 0.44 peaks/sec, and the maximum value of PIPP-R was 10.8 ± 3.3. A correlation between the skin conductance and PIPP-R was not found at any time during the eye examination. Repeated measures correlation analyses showed only a moderate positive correlation between PIPP-R and number of skin conductance fluctuation values.

CONCLUSION

There were significant changes in both PIPP-R and number of skin conductance fluctuations during retinopathy of prematurity screening, reaffirming that this procedure is painful and stressful. The number of skin conductance fluctuations and PIPP-R are not significantly correlated, which likely reflects that these parameters evaluate different but complementary aspects of neonatal pain responses.

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.

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.

Pain assessment in the critically ill mechanically ventilated adult patients: Comparison between skin conductance algesimeter index and physiologic indicators

Background and Objectives:

Critically ill patients are unable to communicate effectively, so it is difficult to assess their pain and analgesic requirement. Skin conductance algesimeter (SCA) index is a device that primarily measures changes in skin conductance real time to assess pain.

Methods:

We planned this quantitative prospective observational study to assess pain in the critically ill mechanically ventilated patients in comparison to physiologic indicators such as blood pressure and heart rate. A repeated measures design was chosen, and a sample size of 180 was taken from 60 patients with sepsis, acute exacerbations of chronic obstructive pulmonary disease, community-acquired pneumonia, and postsurgical patients in the Intensive Care Unit (ICU). The two painful procedures chosen were tracheal suction and patient positioning. The data were collected at rest, at tracheal suctioning, 20 min later at positioning of the patient, and final reading 20 min later. Three testing periods, each including 4 assessments for a total of 12 pain assessments with sixty patients, were completed during each patient's ICU course. A total of six assessments were done with the patient at rest and three each with pain stimulus of tracheal suctioning and patient positioning.

Results:

There was a significant increase in both hemodynamic variables during painful procedures except for the heart rate during positioning. The correlation between the SCA index and Ramsay scale was negative and significant.

Conclusions:

This instrument might prove useful to measure pain in uncommunicative critically ill patients and to evaluate the effectiveness of analgesic treatment and adapt it.

Detecting autonomic response to pain in Rett syndrome

OBJECTIVE

To quantify pain response in girls affected by Rett syndrome (RTT) using electrodermal activity (EDA), a measure of skin conductance, reflecting sympathetic activity known to be modulated by physical and environmental stress.

METHODS

EDA increase, heart rate (HR) increase and Face Legs Activity Cry Consolability (FLACC) values calculated during venipuncture (invasive) and vital signs collection (non-invasive) events were compared with values calculated during a prior baseline and a RTT clinical severity score (CSS).

RESULTS

EDA and HR increase were significantly higher than baseline during venipuncture only and not significantly correlated with FLACC or CSS. EDA increase was the most sensitive measure of pain response.

CONCLUSIONS

These preliminary findings revealed that motor impairment might bias non-verbal pain scales, underscore the importance of using autonomic measures when assessing pain and warrant further investigation into the utility of using EDA to objectively quantify RTT pain response to inform future RTT pain management.

Comparative heel stick study showed that newborn infants who had undergone repeated painful procedures showed increased short-term pain responses

AIM

We evaluated the short-term effect of repeated pain exposure on the pain responses of newborn infants using different pain assessment methods, as this area had been under-researched.

METHODS

We compared 20 term, large for gestational age infants and 40 term, appropriate for gestational age controls. All had undergone a heel stick for a newborn screening test just before discharge, but the larger babies had also undergone at least other five painful stimuli prior to that. A pulse oximeter and a skin conductance algesimeter (SCA) were connected to the babies during the heel prick, and video recordings were made. Crying time, the Neonatal Infant Pain Scale (NIPS), heart rate, peripheral oxygen saturation (SpO₂ ) and SCA measurements were compared within and between the groups.

RESULTS

After the heel prick, the crying time (p = 0.021) and NIPS (p = 0.013) scores were significantly higher in the study group and the SpO₂ levels were significantly lower (p = 0.009), but the heart rate (p = 0.981) was not significantly different between the groups. SCA measurements did not differ significantly between the groups.

CONCLUSION

Babies who received more painful stimuli during the first few days of life showed greater pain responses during a subsequent heel prick.

Skin conductance in neonates suffering from abstinence syndrome and unexposed newborns

The aims of this study were to compare the skin conductance (SC) of newborns with opiate-induced neonatal abstinence syndrome (NAS) to that of unexposed newborns and to evaluate the potential of SC readings to detect distress in the context of NAS objectively. The SC of 12 newborns with NAS and 12 unexposed newborns was measured at nine specific times during their first 6 weeks of life. The number of SC fluctuations per second (NSCF/s), the amplitude of SC fluctuation, and the mean level of SC were recorded and analyzed. The SC of newborns treated for symptoms of NAS differed significantly from the SC of unexposed newborns with regard to the NSCF/s (p = 0.04). With the mean level of SC, we observed an interaction between groups over time (p value for interaction = 0.02). With increasing postnatal age, we observed higher values in all three SC parameters.

CONCLUSION

The NSCF/s and the mean level of SC appear to be suitable to reflect the distress of newborns suffering from NAS. As it is known that the sensitivity of SC increases with the level of stress experienced, its potential to indicate elevated stress levels in infants with NAS should be investigated in future studies evaluating different therapy regimens.

WHAT IS KNOWN

• Skin conductance is a result of the filling of palmar and plantar sweat glands innervated by the sympathetic nervous system • Skin conductance can be used as a measure of stress and pain in newborns What is New: • Skin conductance of newborns with neonatal abstinence syndrome (NAS) differs significantly from the SC of non-substance-exposed newborns during the first 6 weeks of life • Skin conductance appears to reflect the increased distress of infants with NAS.

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.

Randomized placebo-controlled trial of sucrose analgesia on neonatal skin blood flow and pain response during heel lance

OBJECTIVES

To evaluate the effect of oral sucrose on skin blood flow (SBF; perfusion units; PU) measured by Laser Doppler Imager (LDI) in term newborns and pain response (Neonatal Infant Pain Scale score; NIPS score) during heel lance; (2) determine SBF changes during heel lance; and (3) the relationship between SBF and NIPS.

MATERIALS AND METHODS

Term infants ≤7 days old (n=56) undergoing routine heel lance were randomized to pretreatment with 2.0 mL oral 24% sucrose (n=29) or sterile water (n=27) in a double-blinded, placebo-controlled trial. SBF was assessed by LDI scans and NIPS scores at 10 minutes before lance, immediately after lancing, and 5 minutes after blood extraction. Mean SBF and median NIPS scores were compared between groups using General Linear Model or Kruskal-Wallis. Regressions examined the relationship between SBF immediately after heel lance and NIPS score.

RESULTS

Mean SBF and median NIPS scores immediately after heel lance were lower in sucrose-treated infants (167.9±15.5 vs. 205.4±16.0 PU, P=0.09; NIPS 1 [interquartile range 0 to 4] vs. NIPS 3 [interquartile range 0 to 6], P=0.02), although no significant difference in mean SBF. During heel lance NIPS score was predictive of SBF. An increase of 1 in NIPS score was associated with 11 PU increase in SBF (R=0.21; P=0.09) for sucrose, and 16 PU increase for placebo-treated infants (R=0.20; P=0.014).

CONCLUSIONS

Increased SBF assessed by LDI is a pain response among term neonates after routine heel lance, which was not completely attenuated by oral sucrose administration. Increased SBF is associated with NIPS scores. Sucrose analgesic efficacy evidenced by decreased NIPS scores for the sucrose group. Association of SBF with NIPS scores suggests that LDI is potentially useful for assessing newborn procedural pain.

Preterm infants' behaviors and skin conductance responses to nurse handling in the NICU

Stress response patterns are indicative of the neonate's unique ability to cope with environmental demands and can be evaluated through autonomic and behavioral response parameters.

OBJECTIVE

To characterize stress responses during tactile stimulation to standard nurse handling in the NICU, and their association with severity of illness in preterm infants.

METHODS

Thirty preterm neonates were studied at postnatal day 4-5 during standard nurse caregiving. Heart rate (HR), respiratory rate (RR), skin conductance responses per second (SCR/s), and NIDCAP® stress behaviors were recorded before and during care. Non-parametric tests were used to assess differences from before to during care. Pearson's correlations were used to determine the association of biological and behavioral variables to the score for neonatal acute physiology (SNAP), a severity of illness index.

RESULTS

HR, RR, SCR/s and NIDCAP® behaviors (motor and attentional cues, and ability to self-console) increased from before to during the care (p < 0.01). NIDCAP® behaviors showed a significant negative association to the SNAP score (R = -0.45, p < 0.05).

CONCLUSIONS

HR, RR, SCR/s and NIDCAP® behaviors significantly increased during care. NIDCAP® stress behaviors were influenced by the severity of illness of the infant, while SCR/s was not influenced by severity of illness.

Pain-preventing strategies in mammography: an observational study of simultaneously recorded pain and breast mechanics throughout the entire breast compression cycle

Background

Many women consider mammography painful. Existing studies on pain-preventing strategies only mention pain scores reported before and after breast compression. Studying the pain dynamics during the entire compression cycle may provide new insights for effective pain-preventing strategies.

Methods

This observational study included 117 women who consented to use a custom turning knob to indicate their pain experience during standard mammographic breast compressions in the Academic Medical Center in Amsterdam, The Netherlands. The breast thickness, compression force, contact area, contact pressure and pain experience were recorded continuously. Breast volume was calculated retrospectively from the mammograms. We visualized the progression of pain in relation to breast mechanics for five groups of breast volumes and we performed multivariable regressions to identify factors that significantly predict pain experience.

Results

Breast compressions consisted of a deformation phase for flattening, and a clamping phase for immobilization. The clamping phase lasted 12.8 ± 3.6 seconds (average ± standard deviation), 1.7 times longer than the 7.5 ± 2.6 seconds deformation phase. During the clamping phase, the average pain score increased from 4.75 to 5.88 (+24%) on a 0 – 10 Numerical Rating Scale (NRS), and the proportion of women who reached severe pain (NRS ≥ 7) increased from 23% to 50% (more than doubled). Moderate pain (NRS ≥ 4) was reported up to four days after the mammogram. Multivariable analysis showed that pain recollection of the previous mammogram and breast pain before the compression, are significant predictors for pain. Women with smallest breasts experienced most pain: They received highest contact pressures (force divided by contact area) and the pressure increased at the highest rate.

Conclusion

We suggest further research on two pain-preventing strategies: 1) using a personalized compression protocol by applying to all breasts the same target pressure at the same, slow rate, and 2) shortening the phase during which the breast is clamped.

Monitoring depth of anesthesia: from consciousness to nociception. A window on subcortical brain activity

Anesthesia results from several inhibitor processes, which interact to lead to loss of consciousness, amnesia, immobility, and analgesia. The anesthetic agents act on the whole brain, the cortical and subcortical areas according to their receptor targets. The conscious processes are rather integrated at the level of the cortical neuronal network, while the nonconscious processes such as the nociception or implicit memory require subcortical processing. A reliable and meaningful monitoring of depth of anesthesia should provide assessment of these different processes. Besides the EEG monitoring which gives mainly information on cortical anesthetic effects, it would be relevant to have also a subcortical feedback allowing an assessment of nociception. Several devices have been proposed in this last decade, to give us an idea of the analgesia/nociception balance. Up to now, most of them are based on the assessment of the autonomic response to noxious stimulation. Among the emerging clinical devices, we can mention those which assess vascular sympathetic response (skin conductance), cardiac and vascular sympathetic response (surgical pleth index), parasympathetic cardiac response (analgesia nociception index), and finally the pupillometry which is based on the assessment of the pupillary reflex dilatation induced by nociceptive stimulations. Basically, the skin conductance might be the most adapted to assess the stress in the awake or sedated neonate, while the performances of this method appear disappointing under anesthesia. The surgical pleth index is still poorly investigated in children. The analgesia nociception index showed promising results in adults, which have to be confirmed, especially in children and in infants, and lastly pupillometry, which can be considered as reliable and reactive in children as in adults, but which is still sometimes complicated in its use.

Cerebral hemodynamic changes and pain perception during venipuncture: is glucose really effective?

Newborns are exposed to a considerable number of painful stimuli. This study is aimed to investigate the effects of 30% glucose solution and nonnutritive sucking on pain perception during venipuncture. Twenty-five term infants were randomized as receiving 30% dextrose (group 1) or sterile water (group 2). Neonatal Infant Pain Scale scores, skin conductance algesimeter recordings, and near-infrared spectroscopy measurements were recorded during the procedure. Neonatal Infant Pain Scale and skin conductance algesimeter results were decreased in both groups from that during venipuncture to after the procedure. Group 1 had lower Neonatal Infant Pain Scale scores compared with group 2 after venipuncture, different from the skin conductance algesimeter, where no difference was observed between groups. In group 1, cerebral blood volume increased after venipuncture. Glucose does not attenuate the Neonatal Infant Pain Scale score and skin conductance algesimeter index during venipuncture, but it leads to a lower Neonatal Infant Pain Scale score after venipuncture unlike the skin conductance algesimeter index, which was not lowered.

Does skin-to-skin contact reduce stress during diaper change in preterm infants?

BACKGROUND

Skin-to-skin contact reduces pain response in preterm infants subjected to minor painful procedures, such as heel lance. Diaper change is a procedure performed several times daily in hospitalized preterm infants. Routine care giving tasks such as diaper change may be stressful for the infant.

AIMS

The purpose of this study was to investigate whether diaper change induces stress and if skin-to-skin contact could reduce such stress, measured by changes in skin conductance.

STUDY DESIGN

This was a randomized crossover pilot study in 19 preterm infants with gestational age between 28 and 34 weeks. The diaper change procedure was done twice in each infant, once during skin-to-skin contact, and once in incubator or bed with the mother present.

OUTCOME MEASURES

During diaper change heart rate (HR), peripheral oxygen saturation (SpO2), and changes in skin conductance (SC) peaks per sec, using the Skin Conductance Algesimeter (SCA), were registered.

RESULTS

The mean SC peaks/sec increased/decreased significantly under/after change of diapers which thereby underpins that this is a stressful procedure for the preterm infant. Skin-to-skin contact (SSC) entails significantly lower stress levels (p<0.05) compared to diaper changed in an incubator/bed measured by the SCA.

CONCLUSIONS

Diaper change is a stressful procedure for preterm infants and may be ameliorated by skin-to-skin contact.

Intubation in the delivery room: experience with nasal midazolam

BACKGROUND

Neonates are often intubated in the delivery room (DR) without anesthesia because vascular access is impossible.

AIMS

To assess neonatal comfort and adverse events after use of nasal midazolam (nMDZ) for intubation in the DR.

STUDY DESIGN

Prospective data collection over 6months on the intubation of neonates with respiratory distress requiring tracheal instillation of surfactant.

SUBJECTS

Twenty-seven neonates with median (Q25-75) gestational age and birthweight of, respectively, 29 (27-33)weeks and 1270 (817-1942)g received a 0.1mg/kg dose of nMDZ, and intubation was performed at the onset of tonus resolution or apnea.

OUTCOME MEASURES

Comfort was assessed with a scale of hetero-pain assessment and electrical skin conductance monitoring. Continuous pulse oximetry was recorded in the first postnatal hour, with oscillometric blood pressure measurement every 10min.

RESULTS

Seventy percent of the patients required a single dose, with intubation performed 4.8 (3-9)min after administration. Combined electro-clinical assessment found adequate comfort during the procedure in 68% of neonates. Mean blood pressure decreased from 39 (34-44)mmHg before to 31 (25-33)mmHg 1h following nMDZ (p=0.011).

CONCLUSION

nMDZ provided rapid and effective sedation to intubate neonates in the DR but potentially exposed them to hypotension, thus requiring close hemodynamic monitoring.

Pain assessment and measurement in neonates: an updated review

Pain assessment and measurement are the cornerstones of pain management. Pain assessment connotes a comprehensive multidimensional description. Conversely, pain measurement provides a numeric quantitative description of each factor illustrating pain qualities. Pain scales provide a composite score used to guide practice and research. The type of infant pain instrument chosen is a significant factor in guiding pain management practice. The purpose of this review was to summarize current infant pain measures by introducing a conceptual framework for pain measurement. Although more than 40 infant pain instruments exist, many were devised solely for research purposes; several of the newly developed instruments largely overlap with existing instruments. Integration of pain management into daily practice remains problematic. Understanding how each instrument measures infant pain allows clinicians to make better decisions about what instrument to use with which infant and in what circumstances. In addition, novel new measurement techniques need further testing.

Comparison of skin conductance measurements and subjective pain scores in children with minor injuries

AIM

Objective measures of perceived pain may aid clinicians in decision-making regarding analgesia. This study aimed to assess the effectiveness of an algesimeter to assess the pain response of children to minor injury when compared with self-report.

METHODS

A commercially available skin conductance algesimeter was used to record pain in children presenting with a minor injury to a district general hospital. The recordings were compared with self-reported pain scores using the Wong-Baker FACES(®) Pain Rating Scale.

RESULTS

Sixty-seven children below 16 years of age (36 females, 53.7%, mean age 11.9 years, standard deviation 3.1 years) were assessed. There was a significant correlation between self-reported pain and number of fluctuations in skin conductance per second for girls (r = 0.325, p = 0.027), but not for boys (r = 0.160, p = 0.194). There was no significant association between self-reported pain and number of fluctuation in skin conductance per second and patient age.

CONCLUSION

There was a significant correlation between self-reported pain and the number of fluctuations in skin conductance in girls, but not boys. There may be a number of reasons for this gender variation, including difficulty in rating pain and lack of sensitivity in the pain rating scale.

Skin conductance as a marker of pain in infants of different gestational age

AIMS

To assess the use of skin conductance as an objective measure of pain in infants of different gestational age. A second aim was to investigate the relationship between skin conductivity and selected physiological and behavioural variables (oxygen saturation, heart rate and behavioural state).

METHODS

Infants were divided according to gestational age into the following 3 groups; group A: 25+0-31+6 weeks (13 infants), group B: 32+0-35+6 weeks (25 infants), group C: 36+0-41+6 weeks (19 infants). The pain stimulus was blood sampling.

RESULTS

The most sensitive parameter for describing changes in skin conductance related to pain was peak per second. No other parameter correlated with the physiological variables chosen. The results showed that the inability to determine basal skin conductance is a crucial disadvantage to practical application. The lack of correlation between conductance parameters and gestational age is surprising.

CONCLUSION

We conclude that the Peak per Second is the best parameter for evaluating skin conductance in infants and it is not influenced by gestational age. Peaks per Second correlate only with Prechtl's Scale of behavioural state and not with the physiological parameters chosen.

COMFORT behaviour scale and skin conductance activity: what are they really measuring?

AIM

To assess how efficiently the COMFORT behaviour scale measures acute pain in neonates, in comparison with skin conductance activity, a validated measure of pain and stress.

METHODS

Images of 36 newborns were analysed before, during and after painful heel pricks to measure glucose levels and compared with skin conductance activity variables.

RESULTS

Scale indicators and skin conductance variables were sensitive to changes in the periods 'during-before' and 'during-after' (Wilcoxon's test, p < 0.01). Significant values were found between all scale indicators and number of waves for Kendall's coefficient (p < 0.05), although responses differed when it came to how long they took to increase and correlations varied from fair to moderate (r < 0.6). Facial tension was more closely related to 15 sec after the painful event, while crying and calmness were more closely related to the later intervals (30 and 180 sec).

CONCLUSION

All scale indicators were related to skin conductance activity in all periods, indicating pain perception. Facial tension was the most efficient indicator, while others varied in performance after painful events and possibly indicated stress after trauma. These results are discussed from a phenomenological approach and in an anxiety paradigm.

Monitoring of pain and stress in an infant with asphyxia during induced hypothermia: a case report

The purpose of this article was to study an infant who suffered from asphyxia undergoing induced hypothermia with regard to (1) describe the pain and stress as measured by physiological variables skin conductance algesimeter (SCA) and pain rating scales, (2) the correlation between SCA and pain rating scales, and (3) how temperature cycles in the cooling blanket affect the response of the sympathetic nervous system as measured by the SCA and physiological variables. A single prospective case study was used for this article. Data were recorded every 15 minutes for 96 hours. Each observation was categorized according to treatment phase: cooling 0 to 72 hours, rewarming, and controlled normal temperature up to 96 hours. Structured observations were carried out and all nursing care was documented. In addition, 5 periods with no other nursing interventions were identified in which data were recorded every minute for analysis. Skin conductance algimetry showed a variable response during treatment. During cooling, 68% of the 15-minute periods, signs of stress and pain were recorded. During rewarming, the corresponding figure was 83%. During the time sequences with normal temperature, 89% of the periods were associated with stress and pain. During 80% of the nursing procedures, the SCA showed stress and pain. There was no correlation between the pain-rating scales and SCA. When the cooling blanket temperature was lower than core temperature, the infant had more stress and pain according to SCA (P < .001) and an increase in heart rate and blood pressure (P < .001). In infants during induced hypothermia, SCA seem to detect pain and stress. Future evaluation of SCA for the detection of pain and stress during hypothermia treatment is necessary. Pain-rating scales do not appear reliable in this case report.

Skin conductance variations compared to ABC scale for pain evaluation in newborns

OBJECTIVES

To validate spontaneous skin conductance variations as a specific reliable mean to measure pain in full-term healthy newborns during heel stick, comparing it with the ABC scale. To compare oral sucrose to wrapping effectiveness for non-pharmacological analgesia during the same procedure.

METHOD

All recruited newborns (n = 158) underwent a heel stick for metabolic screening at 48 h of life with non-pharmacological analgesia by oral sucrose (group A) or wrapping (group B) according to randomization. Their pain was estimated by ABC scale score (standard method) and measured by skin conductance variations.

RESULTS

A positive correlation was founded between peaks per sec measure and ABC score (rs = 0.303, p < 0.005). ABC score in group A was lower than in group B (p < 0.001). Difference in mean ABC score among newborn subgroups treated by different nurses was not statistically significant for wrapping while it was significant for sucrose (p = 0.001).

CONCLUSIONS

Skin conductance measurement device is a reliable method to evaluate pain. Novel technological devices may be a useful support to clinical observation in this field. Oral sucrose is more effective than wrapping in reducing pain. Operators should be well periodically re-trained in performing non pharmacological analgesia during minor procedure on newborns.

Low skin conductance activity in infancy predicts aggression in toddlers 2 years later

Low autonomic nervous system activity is claimed to be a biomarker for aggressive and antisocial behavior. Although there is evidence that low skin conductance activity (SCA) accounts for variation in the severity of antisocial behavior and predicts the onset of aggression in children and adults, it is unknown whether SCA measured in infancy can predict the development of aggression. We measured SCA in 70 typically developing 1-year-old infants at baseline, during an orienting habituation paradigm, and during a fear challenge. We also observed the infants' fear behavior, and each mother rated her infant's temperament and her attachment to her child. At follow-up, mothers rated the children at 3 years old for aggressive and nonaggressive behavior problems. Low infant SCA predicted aggressive behavior, but there was no association between SCA and nonaggressive behavior problems. Mothers' ratings of the infants' temperament and their maternal attachment and the infants' observed fearlessness did not predict later aggression. These results suggest that SCA is a specific biomarker for aggression in low-risk samples of infants.

Analysis of acute pain scores and skin conductance measurements in infants

BACKGROUND

Skin conductance (SC) has been previously used to measure acute post-operative pain in adults and older children (>1year old).We have investigated the ability of SC to predict the severity of post-operative pain scores in the exclusively infant population.

METHODS

Infants (ages 6-12months) scheduled for elective surgery were recruited for the study. Data for behavioral pain scores and SC values - frequency of electrodermal responses per second (EDR/s), peak and basal levels, were recorded in the post-anesthesia care unit (PACU). Blood samples were collected for genomic studies, including single nucleotide polymorphisms (SNP) in morphine opioid receptor (MOR) A118G and the catechol-O-methyltransferase (COMT) G1947A genes.

RESULTS

31 infants, mean age 8.9months (±1.9); mean weight 8.5kg (±1.1) were included in the final study analysis. With every 0.1 unit increase in peak values noted on SC, the odds of higher pain scores were found to be 5% greater (p=0.03). For predictability of moderate to severe pain, the area under the curve, sensitivity and specificity were 0.64, 90.9% and 51.4% respectively for peak values and 0.66, 54.5% and 79.4% respectively for EDR/s values. Genotyping performed in 16 out of 31 infants demonstrated that the carriers of MOR 118G allele had consistently higher basal SC values in the PACU.

CONCLUSION

Peak SC values may serve as indicators of unmitigated pain. Further studies are needed to fully investigate the effect of MOR A118G SNP on the post operative pain scores and SC values in the larger infant population in order to validate both the clinical significance of the skin conductance for routine pain assessment in infants and the observed genetic effect.

Pain monitoring in anesthetized children: first assessment of skin conductance and analgesia-nociception index at different infusion rates of remifentanil

BACKGROUND

Analgesia and nociception can not be specifically monitored during general anesthesia. Movement of the patient or hemodynamic variations are usually considered as symptoms of insufficient analgesia. The measure of skin conductance (SC) allows an assessment of peripheral sympathetic activity. The analgesia-nociception index (ANI) provides an evaluation of the parasympathetic activity based on heart rate variability. These two non-invasive monitors might allow a better assessment of perioperative nociception.

OBJECTIVES

Describe the profiles of SC and ANI after a standardized nociceptive stimulation, in anesthetized children, at different infusion rates of remifentanil.

MATERIALS/METHODS

For this pilot study, 12 children (8.4 ± 5 years) scheduled for middle-ear surgery were anesthetized with desflurane to maintain a bispectral index at 50. Remifentanil was used for analgesia, at an initial infusion rate of 0.2 μg·kg(-1) ·min(-1) . Remifentanil infusion rate was then decreased: Five steady-state periods of 10 min were obtained at 0.2, 0.16, 0.12, 0.08, and 0.04 μg·kg(-1) ·min(-1) . At the end of each period, a standardized tetanic stimulation was applied to the patient. Variations in heart rate, blood pressure, SC, and ANI were recorded before and after each stimulation.

RESULTS

After the stimulation, ANI was significantly decreased compared with prestimulation values for all remifentanil infusion rates. This decrease was greater at 0.04 μg·kg(-1) ·min(-1) than at the other infusion rates. SC, heart rate, and blood pressure were not modified by the stimulations, whatever the dose of remifentanil.

CONCLUSION

ANI might provide a more sensitive assessment of nociception in anesthetized children than hemodynamic parameters or skin conductance.

Pharmacological treatment of neonatal pain: in search of a new equipoise

Inadequate management of pain in early human life contributes to impaired neurodevelopmental outcome and alters pain thresholds, pain or stress-related behavior and physiological responses. However, there are also emerging animal experimental data on the impact of exposure to analgo-sedatives on the incidence and extent of neuro-apoptosis. Since this association has also been suggested in humans, the pharmacological treatment of neonatal pain is in search of a new equipoise since these 'conflicting' observations are the main drivers to further reconsider our current treatment regimens. This review focuses on new data concerning clinical pharmacology of morphine, followed by data on more recently introduced opioids like remifentanil and tramadol, locoregional anesthesia and minimally invasive techniques in neonates, and finally with data on intravenous paracetamol. Since the available data are still incomplete, priorities for both clinical management and future research will be proposed.

Spontaneous cries can alter the physiological well-being and cerebral oxygenation of very preterm infants

INTRODUCTION

Infant crying is a major expression of distress and can occur without any exogenous stimulation. Little is known, however, about the effects of crying on physiological homeostasis in very preterm infants (VPIs).

METHODS

Environmental, behavioral (video and audio recording) and physiologic (heart rate [HR], respiratory rate [RR], and systemic [SaO(2)] and regional cerebral oxygenation [rSO(2)]) parameters were prospectively evaluated over 10h in 18 VPIs (median gestational age, 28 [27-31] weeks). Only episodes of "spontaneous" and isolated cries were analyzed. Changes in parameters were compared over 5-second periods between baselines and 40s following the onset of crying. Two periods were distinguished: 0-20s (a) and 20-40s (b). Minimal and/or maximal values in these periods were also compared to the baseline.

RESULTS

Of the 18 VPIs initially studied, 13 (72%) presented crying episodes (CE). They experienced 210 "spontaneous" and isolated CE, with a median of 9 [range, 1-63] CEs per child. Physiological values varied significantly from the baseline with mainly a mean decrease in HR of -4.8±5.3 beats/min (b) after an initial mean increase of +2.6±2.0 beats/min (a); a mean decrease in RR of -3.8±4.8 cycles/min (a), followed by a mean increase of +5.6±7.3 cycles/min (b) and mean unidirectional decreases in SaO(2) and rSO(2) (minimal values) of -1.8±2.3% and -2.5±3.0%, respectively.

CONCLUSION

Spontaneous cries can alter the homeostasis of VPIs. Their possible adverse consequences and high occurrence emphasize the need for better prevention and response to them.