Postoperative pain expression in preschool children: validation of the child facial coding system

[Pain assessment for children and adolescents with autism spectrum disorders (ASD): A systematic review]

OBJECTIVE

Pain in children and adolescents with autism spectrum disorders remains underdiagnosed due to their inherent communication difficulties. The goal of this review is to identify the most suitable methods for assessing pain in this population and for evaluating the specific perceptions of, or behavioural reactions to, pain whilst considering disorder severity and specifiers (with or without accompanying intellectual impairment, with or without accompanying language impairment).

METHOD

A systematic review and analysis of the international literature was conducted.

RESULTS

Fourteen studies were selected. No difference was found in pain-related behaviours based on the age or gender of children or adolescents with autism. Three studies showed pain-related behaviours in autism spectrum disorders to be similar to control groups. Other studies showed specific behavioural responses in autism spectrum disorders with a longer physiological and behavioural recovery time associated with an episode of acute pain in this population. Similarly, the three studies that focused on sensory perceptions of pain all showed differences in the autism spectrum disorders population compared to control groups. In hospital or daily life contexts, studies essentially showed idiosyncratic expressions, hypervigilance, motor agitation, negative emotional reactions, or vocalizations. Regarding the association of autism severity with hyposensitivity to pain, the results remain unclear even when language disorders or intellectual disabilities are also present (in conjunction with autism). The Non-Communicative Children Pain Checklist and its translation into French and Italian showed good internal validity and was used by almost half of the studies in hetero-assessment, mostly by parents. Studies recommend the inclusion of parents in the assessment in order to optimise the evaluation process. Similarly, analysis of parent/child/caregiver interviews from the studies highlights the importance of personalizing pain assessment of children and adolescents, taking into account subject-specific characteristics, pathology, and context.

CONCLUSION

An integrative and personalized approach to pain assessment appears to be the most appropriate for enhancing the understanding and detection of pain in individuals with autism spectrum disorders. This approach aligns well with a care setting where a nominated professional with a good expertise in autism is responsible for pain assessment. Given the complexity of identifying pain in individuals with autism, further qualitative studies, in conjunction with new pain exploration technologies, are considered necessary as well as a more extensive categorization of the population studies.

Racial Bias in Pediatric Pain Perception

Racial disparities in pediatric pain care are prevalent across a variety of health care settings, and likely contribute to broader disparities in health, morbidity, and mortality. The present research expands on prior work demonstrating potential perceptual contributions to pain care disparities in adults and tests whether racial bias in pain perception extends to child targets. We examined the perception and hypothetical treatment of pain in Black and White boys (experiment 1), Black and White boys and girls (experiment 2), Black and White boys and adult men (experiment 3), and Black, White, Asian, and Latinx boys (experiment 4). Across this work, pain was less readily perceived on Black (vs White) boys' faces-though this bias was not observed within girls. Moreover, this perceptual bias was comparable in magnitude to the same bias measured with adult targets and consistently predicted bias in hypothetical treatment. Notably, bias was not limited to Black targets-pain on Hispanic/Latinx boys' faces was also relatively underperceived. Taken together, these results offer strong evidence for racial bias in pediatric pain perception. PERSPECTIVE: This article demonstrates perceptual contributions to racial bias in pediatric pain recognition. Participants consistently saw pain less readily on Black boys' faces, compared with White boys, and this perceptual bias consistently predicted race-based gaps in treatment. This work reveals a novel factor that may support pediatric pain care disparities.

Analyzing facial action units in children to differentiate genuine and fake pain during inferior alveolar nerve block: a cross-sectional study

This study aimed to investigate the association between facial action units and pain levels in Syrian children, focusing on both genuine and fake pain expressions. A total of 300 Syrian children aged 6-9 years participated in the study. Pain levels were assessed using the validated Face, Legs, Activity, Cry, Consolability scale, and facial expressions were analyzed using the Facial Action Coding System. The children were asked to mimic their feelings after receiving a dental injection to elicit fake pain expressions. Statistical analysis, including multinomial logistic regression and chi-square tests, was conducted to determine the Action Units (AUs) associated with each pain level and to compare the differences between real and fake pain expressions. The results revealed significant associations between specific AUs and pain levels. For real pain expressions, the most activated AUs across different pain levels with positive coefficient values of correlation (P-value < 0.01) were analyzed. In contrast, for fake pain expressions, AU12 and AU38 were consistently observed to be the most activated. These findings suggest that certain AUs are uniquely associated with fake pain expressions, distinct from those observed in real pain expressions. Furthermore, there were no significant differences between boys and girls in terms of their genuine and fake pain expressions, indicating a similar pattern of AU activation (P-value > 0.05). It was concluded that AUs 4, 6, 41, and 46 were associated with mild pain, and AUs 4, 6, 41, 46, and 11 were associated with moderate pain cases. In severe pain, AUs 4, 6, 7, 9, 11, and 43 were associated. In fake pain feelings, AU43, AU38, and AU12 were the most activated with no difference between boys and girls.

Correlation between FLACC scale score and analgesic requirement in children undergoing Minimally Invasive Surgery

Postoperative pain presents several challenges in pediatric Minimally Invasive Surgery. The Faces, Legs, Activity, Cry, and Consolability (FLACC) scale is a valid scale for pediatric postoperative pain. The aim of our study was to assess postoperative pain using FLACC scale and to analyze the correlation between FLACC scale score and analgesic requirement in children underwent Minimally Invasive Surgery. We retrospectively analyzed data of 153 children aged 2 months-3 years who underwent Minimally Invasive Surgery in our unit from January 2019 and December 2019. Postoperative pain assessment was established using FLACC scale. In each patient were analyzed the correlation between FLACC score and analgesic requirement. Pain evaluation was assigned immediately after surgery and at 15 and 60 minutes. 36.6% of patients (56 children) were asleep so considered pain free; 21.6% of patients (33 children) had a FLACC score more than 7 so they required analgesics and the pain assessment 15 and 60 minutes after was significantly lower. 41.8% of patients (64 children) had a postoperative FLACC score less than 3, so they didn't require any analgesic treatment. On the basis of our results, we recommend FLACC scale for postoperative pain assessment in children underwent MIS aged 2 months-3 years. FLACC scale is an effective and precise scale in detection of postoperative analgesic requirement in children and it could be extended in different age groups with further research.

Facial expressions of pain in daily clinical practice to assess postoperative pain in children: Reliability and validity of the facial action summary score

BACKGROUND

Behavioural pain scales are recommended to assess postoperative pain for children who are too young to use self-report tools. Their main limitation is underestimation of pain in the days following an intervention. Although relevant, facial expression is not used in daily clinical practice. This prospective study aimed to assess the validity and reliability of the Facial Action Summary Score (FASS), a five-item scale, to assess postoperative pain until hospital discharge in children <7 years.

METHODS

Assessments of pain and anxiety of 123 children using FASS and validated scales were used to study the psychometric validity of the FASS in clinical practice.

RESULTS

The content validity was previously investigated in a development study. The internal validity of the FASS was high with excellent reliability (intraclass coefficient = 0.94) and a high Cronbach α (0.89). Convergent validity with pain scales (FLACC [Face, Legs, Activity, Cry, Consoling] and FPS-R [Faces Pain Scale - Revised]) was high (r > 0.8). Sensitivity to change was verified by a significant decrease in the score after rescue analgesia. For a threshold of 2/5, the FASS shows excellent specificity (97%) and sensitivity (82%). The low number of false negatives is the main strength of this tool.

CONCLUSIONS

This work highlights the interest in using facial expression in daily clinical practice to manage postoperative pain. The FASS is easy to use with excellent psychometric properties and is particularly sensitive to measure pain in the days following surgery.

SIGNIFICANCE

The aim of this study was to prove that facial expression of pain can be used in clinical practice to measure postoperative pain in children. The reduced number of false negatives is the main strength of this tool.

Surgical management of the patient living with autism

Background

Although 1 in 59 children currently born are diagnosed with autism spectrum disorder (ASD), little is known on how to best manage those patients who require surgical intervention.

The purpose of this study is to (1) investigate the best care strategies for surgical patients living with autism spectrum disorder (2) provide recommendations on how to apply those strategies to clinical practice.

Methods

A literature review was conducted to investigate the best clinical practices for optimizing surgical care for individuals living with autism spectrum disorder. Relevant articles were selected and examined, and individual references from those articles were manually searched using Ovid Medline and Google Scholar.

Results

The wide spectrum of symptoms associated with autism spectrum disorder pose unique challenges for surgical management. Early coordination with the patient and family optimizes the development of an effective care plan. Strategies include identifying triggers for anxiety as well as soothing mechanisms, performing surgery in the morning, completing preoperative paperwork prior to surgery, choosing appropriate analgesia and anxiolytics, and fast resumption of normal routines. Based on these findings a surgical checklist was created to aid in treating the patient with autism spectrum disorder. The checklist provides insight into navigating the surgical experience and emphasizes planning surgical interventions to most effectively fit individual patient needs.

Conclusion

The surgical treatment of those living with autism spectrum disorder poses unique challenges for the health care team. The widespread adoption of such individualized approaches encompassing pre/intra/post-operative will become more important as these children grow into adults with increased needs for surgical services.

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Early coordination optimizes development of an effective care plan.

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Identifying triggers for anxiety as well as soothing mechanisms can be helpful.

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Performing surgery first in the morning decreases deviation from normal routines.

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Completing preoperative paperwork prior to surgery reduces surgical day work.

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Choosing appropriate analgesia and anxiolytics assists in surgical interventions.

The facial expression of pain in humans considered from a social perspective

The social modulation of pain in humans has been neglected so far with respect to verbal as well as non-verbal communication of pain. The facial pain expression is a powerful way to communicate pain, and there are some theoretical accounts available on how social modulation may affect the encoding of the facial expression of pain. Some accounts, particularly in the pain field, are proximate explanations on the mechanisms involved, whereas an evolutionary psychology account takes a more comprehensive approach. A review of nine experimental studies revealed that in the majority of studies (6/9), social context had an effect on the facial pain expression, but results were inconsistent. Several conceptual and methodological issues are discussed which may explain these inconsistencies and could help in design of future experimental studies. This article is part of the Theo Murphy meeting issue 'Evolution of mechanisms and behaviour important for pain'.

The challenge of pain assessment in children with cognitive disabilities: Features and clinical applicability of different observational tools

Children with cognitive disabilities are at greater risk of experiencing pain. It has been shown that this paediatric population often receive inadequate pain management. Pain may be very difficult to assess, especially in a defined subgroup with non-communicating intellectual disability or severe cognitive disability. Accordingly, several observational pain assessment tools have been proposed to overcome this issue. Due to the absence of an ideal measurement tool, accurate pain assessment requires, after a case-by-case analysis, selecting the more appropriate tool or a variety of combined instruments. The aim of this work is to provide a comprehensive review of the pain assessment tools commonly used in cognitively impaired children. Critical discussion on features and clinical applicability may suggest how to overcome this difficult challenge. Furthermore, this review will help further research aiming to design new instruments and to improve already-in-use tools.

Clinical experience changes the combination and the weighting of audio-visual sources of information

OBJECTIVE

Although audio and visual information constitute relevant channels to communicate pain, it remains unclear to what extent observers combine and weight these sources of information when estimating others' pain. The present study aimed to examine this issue through the theoretical framework of the Information Integration Theory. The combination and weighting processes were addressed in view of familiarity with others' pain.

METHOD

Twenty-six participants familiar with pain (novice podiatry clinicians) and thirty non-specialists were asked to estimate the level of pain associated with different displayed locomotor behaviors. Audio and visual information (i.e., sound and gait kinematics) were combined across different intensities and implemented in animated human stick figures performing a walking task (from normal to pathological gaits).

RESULTS

The novice clinicians and non-specialists relied significantly on gaits and sounds to estimate others' pain intensity. The combination of the two types of information obeyed an averaging rule for the majority of the novice clinicians and an additive rule for the non-specialists. The novice clinicians leaned more on gaits in the absence of limping, whereas they depended more on sounds in the presence of limping. The non-specialists relied more on gaits than on sounds. Overall, the novice clinicians attributed greater pain levels than the non-specialists did.

CONCLUSION

Depending on a person's clinical experience, the combination of audio and visual pain-related behavior can qualitatively change the processes related to the assessment of others' pain. Non-verbal pain-related behaviors as well as the clinical implications are discussed in view of the assessment of others' pain.

Interprofessional Team's Perception of Care Delivery After Implementation of a Pediatric Pain and Sedation Protocol

BACKGROUND

Pain and agitation are common experiences of patients in pediatric cardiac intensive care units. Variability in assessments by health care providers, communication, and treatment of pain and agitation creates challenges in management of pain and sedation.

OBJECTIVES

To develop guidelines for assessment and treatment of pain, agitation, and delirium in the pediatric cardiac intensive unit in an academic children's hospital and to document the effects of implementation of the guidelines on the interprofessional team's perception of care delivery and team function.

METHODS

Before and after implementation of the guidelines, interprofessional team members were surveyed about the members' perception of analgesia, sedation, and delirium management RESULTS: Members of the interprofessional team felt more comfortable with pain and sedation management after implementation of the guidelines. Team members reported improvements in team communication on patients' comfort. Members thought that important information was less likely to be lost during transfer of care. They also noted that the team carried out comfort management plans and used pharmacological and nonpharmacological therapies better after implementation of the guidelines than they did before implementation.

CONCLUSIONS

Guidelines for pain and sedation management were associated with perceived improvements in team function and patient care by members of the interprofessional team.

A Survey on Computer Vision for Assistive Medical Diagnosis From Faces

Automatic medical diagnosis is an emerging center of interest in computer vision as it provides unobtrusive objective information on a patient's condition. The face, as a mirror of health status, can reveal symptomatic indications of specific diseases. Thus, the detection of facial abnormalities or atypical features is at upmost importance when it comes to medical diagnostics. This survey aims to give an overview of the recent developments in medical diagnostics from facial images based on computer vision methods. Various approaches have been considered to assess facial symptoms and to eventually provide further help to the practitioners. However, the developed tools are still seldom used in clinical practice, since their reliability is still a concern due to the lack of clinical validation of the methodologies and their inadequate applicability. Nonetheless, efforts are being made to provide robust solutions suitable for healthcare environments, by dealing with practical issues such as real-time assessment or patients positioning. This survey provides an updated collection of the most relevant and innovative solutions in facial images analysis. The findings show that with the help of computer vision methods, over 30 medical conditions can be preliminarily diagnosed from the automatic detection of some of their symptoms. Furthermore, future perspectives, such as the need for interdisciplinary collaboration and collecting publicly available databases, are highlighted.

Pain Assessment in Newborns, Infants, and Children

Pain in children is underestimated and undertreated because of lack of pain assessment tools. Pain assessment depends on the cognitive development of the child being tested, clinical context, and pain typology. For children older than age 6 years, pain assessment is based on a self-report. For children younger than age 6 years, behavioral pain scales are needed to assess pain. Numerous pain scales exist. Many are reliable and some are recommended, but all have specific conditions for their use. In this article, we review the available pain scales for children from birth to adolescence. We provide the validity criteria of each pain scale to help caregivers use the adapted tools. We then propose a synthesis of the reliable tools to use based on the pain context. [Pediatr Ann. 2017;46(10):e387-e395.].

Application of the Rat Grimace Scale as a Marker of Supraspinal Pain Sensation after Cervical Spinal Cord Injury

Experimental models of neuropathic pain (NP) typically rely on withdrawal responses to assess the presence of pain. Reflexive withdrawal responses to a stimulus are used to evaluate evoked pain and, as such, do not include the assessment of spontaneous NP nor evaluation of the affective and emotional consequences of pain in animal models. Additionally, withdrawal responses can be mediated by spinal cord reflexes and may not accurately indicate supraspinal pain sensation. This is especially true in models of traumatic spinal cord injury (SCI), wherein spastic syndrome, a motor disorder characterized by exaggeration of the stretch reflex that is secondary to hyperexcitability of the spinal reflex, can cause paroxysmal withdrawals not associated with NP sensation. Consequently, the aim of this study was to utilize an assessment of supraspinal pain sensation, the Rat Grimace Scale (RGS), to measure both spontaneous and evoked NP after a contusion SCI at cervical level 5 in adult male rats. Spontaneous and evoked pain were assessed using the RGS to score facial action units before and after the application of a stimulus, respectively. Rodents exhibited significantly higher RGS scores at week 5 post-injury as compared to baseline and laminectomy controls before the application of the stimulus, suggesting the presence of spontaneous NP. Additionally, there was a significant increase in RGS scores after the application of the acetone. These data suggest that the RGS can be used to assess spontaneous NP and determine the presence of evoked supraspinal pain sensation after experimental cervical SCI.

Validity of the Child Facial Coding System for the Assessment of Acute Pain in Children With Cerebral Palsy

The purpose of the current study was to examine the concurrent and discriminant validity of the Child Facial Coding System for children with cerebral palsy. Eighty-five children (mean = 8.35 years, SD = 4.72 years) were videotaped during a passive joint stretch with their physiotherapist and during 3 time segments: baseline, passive joint stretch, and recovery. Children's pain responses were rated from videotape using the Numerical Rating Scale and Child Facial Coding System. Results indicated that Child Facial Coding System scores during the passive joint stretch significantly correlated with Numerical Rating Scale scores (r = .72, P < .01). Child Facial Coding System scores were also significantly higher during the passive joint stretch than the baseline and recovery segments (P < .001). Facial activity was not significantly correlated with the developmental measures. These findings suggest that the Child Facial Coding System is a valid method of identifying pain in children with cerebral palsy.

An evaluation of instruments for scoring physiological and behavioral cues of pain, non-pain related distress, and adequacy of analgesia and sedation in pediatric mechanically ventilated patients: A systematic review

OBJECTIVES

Advancing technology allows for successful treatment of children with life-threatening illnesses. Effectively assessing and optimally treating a child's distress during their stay in the Pediatric Intensive Care Unit (PICU) is paramount. Objective measures of distress in mechanically ventilated pediatric patients are increasingly available but few have been evaluated. The objectives of this systematic review were to identify available instruments appropriate for measuring physiological and behavioral cues of pain, non-pain related distress, and adequacy of analgesia and sedation in mechanically ventilated pediatric patients, and evaluate these instruments in terms of their psychometric properties.

DESIGN

A systematic review of original and validation reports of objective instruments to measure pain and non-pain related distress, and adequacy of analgesia and sedation in mechanically ventilated PICU patients was undertaken.

DATA SOURCES

A comprehensive search was conducted in 10 databases from January 1970 to June 2011. Reference lists of relevant articles were reviewed to identify additional articles.

REVIEW METHODS

Studies were included in the review if they met pre-established eligibility criteria. Two independent reviewers reviewed studies for inclusion, assessed quality, and extracted data.

RESULTS

Twenty-five articles were included, identifying 15 instruments. The instruments had different foci including: assessing pain, non-pain related distress, and sedation (n=2); assessing pain exclusively (n=4); assessing sedation exclusively (n=7), assessing sedation in mechanically ventilated muscle relaxed PICU patients (n=1); and assessing delirium in mechanically ventilated PICU patients (n=1). The Comfort Scale demonstrated the greatest clinical utility in the assessment of pain, non-pain related distress, and sedation in mechanically ventilated pediatric patients. Modified FLACC and the MAPS are more appropriate, however, for the assessment of procedural pain and other brief painful events. More work is required on instruments for the assessment of distress in mechanically ventilated muscle relaxed PICU patients, and the assessment of delirium in PICU patients.

CONCLUSIONS

This review provides essential information to guide PICU clinicians in choosing instruments to assess pain, non-pain related distress, and adequacy of analgesia and sedation in mechanically ventilated pediatric patients. Effective knowledge translation is essential in the implementation, adoption, and successful use of these instruments.

Impact of parental catastrophizing and contextual threat on parents' emotional and behavioral responses to their child's pain

Limited research has addressed processes underlying parents' empathic responses to their child's pain. The present study investigated the effects of parental catastrophizing, threatening information about the child's pain, and child pain expression upon parental emotional and behavioral responses to their child's pain. A total of 56 school children participated in a heat pain task consisting of 48 trials while being observed by 1 of their parents. Trials were preceded by a blue or yellow circle, signaling possible pain stimulation (i.e., pain signal) or no pain stimulation (i.e., safety signal). Parents received either neutral or threatening information regarding the heat stimulus. Parents' negative emotional responses when anticipating their child's pain were assessed using psychophysiological measures- i.e., fear-potentiated startle and corrugator EMG activity. Parental behavioral response to their child's pain (i.e., pain attending talk) was assessed during a 3-minute parent-child interaction that followed the pain task. The Child Facial Coding System (CFCS) was used to assess children's facial pain expression during the pain task. Results indicated that receiving threatening information was associated with a stronger parental corrugator EMG activity during pain signals in comparison with safety signals. The same pattern was found for parental fear-potentiated startle reflex, particularly when the child's facial pain expression was high. In addition, parents who reported high levels of catastrophizing thought about their child's pain engaged, in comparison with low-catastrophizing parents, in more pain-attending talk when they received threatening information. The findings are discussed in the context of affective-motivational theories of pain.

Children's behavior in the postanesthesia care unit: the development of the Child Behavior Coding System-PACU (CBCS-P)

OBJECTIVE

To develop and validate a behavioral coding measure, the Children's Behavior Coding System-PACU (CBCS-P), for children's distress and nondistress behaviors while in the postanesthesia recovery unit.

METHODS

A multidisciplinary team examined videotapes of children in the PACU and developed a coding scheme that subsequently underwent a refinement process (CBCS-P). To examine the reliability and validity of the coding system, 121 children and their parents were videotaped during their stay in the PACU. Participants were healthy children undergoing elective, outpatient surgery and general anesthesia. The CBCS-P was utilized and objective data from medical charts (analgesic consumption and pain scores) were extracted to establish validity.

RESULTS

Kappa values indicated good-to-excellent (κ's > .65) interrater reliability of the individual codes. The CBCS-P had good criterion validity when compared to children's analgesic consumption and pain scores.

CONCLUSIONS

The CBCS-P is a reliable, observational coding method that captures children's distress and nondistress postoperative behaviors. These findings highlight the importance of considering context in both the development and application of observational coding schemes.

Facial pain expression

SUMMARY People in pain communicate their experience via facial expressions. There has been considerable research into the properties of pain expressions. This article reviews basic findings on the encoding and decoding of pain expression. The facial expression of pain is characterized and recent findings on its assessment and psychometric properties are described. Studies on decoding of pain expression are also reviewed, focusing on observers’ sensitivity to and bias in evaluation of pain expression. Priority areas for future research are identified.

Assessment of acute pain in children: development of evidence-based guidelines

AIM

Detecting children's pain in a healthcare setting can be improved by facilitating pain expression in ways that are appropriate to the child's cognitive development and that can be recognised by their carers. To ensure up-to-date guidance on assessing pain in children, the Royal College of Nursing undertook an evidence-based update of pain assessment guidelines, initially published in 2000.

METHODS

Following systematic review of the psychometric testing literature, a two-stage critical appraisal process was developed to derive a list of robust tools that could be recommended for use in a variety of settings to assess the intensity of a child's acute pain. Studies were appraised on the basis of their relevance to this topic and according to prespecified quality criteria. Tools were assessed for inclusion in guideline recommendations according to minimum validity and reliability thresholds.

RESULTS

Overall the quality of literature was poor, limited by small samples, lack of control groups, unblinded raters and convenience sampling. Twenty-four tools are recommended for use with infants and verbal children without cognitive impairment, 11 of which are purely self-report tools. Eight tools are recommended for use with neonates, some of which require concurrent physiological measures. Four tools are considered valid for use in children with cognitive impairment. All of these tools had shown reliability and validity according to the criteria established for this review.

CONCLUSION

The tools are presented in user-friendly tables that include a guide to their key features and the setting and age groups in which they have been validated. They are accompanied by good practice recommendations from experts and recommendations relating to timing and triggers for pain assessment. These outputs are some of those associated with the full guidelines and supporting material published on the Royal College of Nursing website (http://www.rcn.org.uk/childrenspainguideline).

Social modulation of facial pain display in high-catastrophizing children: an observational study in schoolchildren and their parents

The present study examined existing communal and operant accounts of children's pain behavior by looking at the impact of parental presence and parental attention upon children's pain expression as a function of child pain catastrophizing. Participants were 38 school children and 1 of their parents. Children completed a cold pressor pain task (CPT) twice, first when told that no one was observing (alone condition) and subsequently when told that they were being observed by their parent (parent-present condition). A 3-minute parent-child interaction occurred between the 2 CPT immersions, allowing measurement of parental attention to their child's pain (ie, parental pain-attending talk vs non-pain-attending talk). Findings showed that child pain catastrophizing moderated the impact of parental presence upon facial displays of pain. Specifically, low-catastrophizing children expressed more pain in the presence of their parent, whereas high-catastrophizing children showed equally pronounced pain expression when alone or in the presence of a parent. Furthermore, children's catastrophizing moderated the impact of parental attention upon facial displays and self-reports of pain; higher levels of parental nonpain talk were associated with increased facial expression and self-reports of pain among high-catastrophizing children; for low-catastrophizing children, facial and self-report of pain was independent of parental attention to pain. The findings are discussed in terms of possible mechanisms that may drive and maintain pain expression in high-catastrophizing children, as well as potential limitations of traditional theories in explaining pediatric pain expression.

Pain in children: assessment and nonpharmacological management

Pain perception in children is complex, and is often difficult to assess. In addition, pain management in children is not always optimized in various healthcare settings, including emergency departments. A review of pain assessment scales that can be used in children across all ages, and a discussion of the importance of pain in control and distraction techniques during painful procedures are presented. Age specific nonpharmacological interventions used to manage pain in children are most effective when adapted to the developmental level of the child. Distraction techniques are often provided by nurses, parents or child life specialists and help in pain alleviation during procedures.

Pain in children with cerebral palsy: implications for pediatric physical therapy

PURPOSE

This literature review explores pain assessment tools and psychosocial pain management methods that are pertinent to physical therapy (PT) for children with cerebral palsy (CP).

SUMMARY OF KEY POINTS

Children with CP experience considerable pain that affects quality of life and cooperation during healthcare procedures. Physical therapist-led research on interventions to address pain in this population is limited, despite evidence for the prevalence of pain during PT interventions, and the preponderance of research supporting the use of psychosocial pain management during other healthcare-related pain-inducing procedures.

STATEMENT OF CONCLUSIONS AND RECOMMENDATIONS FOR PHYSICAL THERAPY PRACTICE

Research completed primarily by non-physical therapist healthcare professionals delineate assessment tools and psychosocial pain management techniques that hold promise for evaluating and reducing pain that occurs during PT procedures for children with CP.

Pain assessment and management in children with neurologic impairment: a survey of pediatric physical therapists

PURPOSE

This study explored pain assessment measures and interventions used by physical therapists in the treatment of children with neurologic impairment.

METHODS

Following extensive literature review on pain assessment and intervention, a survey was developed, pilot tested, and posted on the listserv of the Pediatric Section of the American Physical Therapy Association.

RESULTS

Eighty percent of the respondents used subjective measures to assess pain, 70% used self-report scales, and 41% used behavioral and physiological measures. Behaviors frequently used included vocalizations, facial expression, and irritability. Rarely used cues included decreased attention, withdrawal, and changes in sleeping and eating behaviors. Therapists used research-supported pain interventions such as distraction and praise as well as potentially harmful distress producing measures such as procedural talk and reassurance.

CONCLUSION

Further research is needed to determine the feasibility of using behavioral pain assessment measures during physical therapy sessions. Physical therapist continuing education regarding nonpharmaceutical pain interventions is indicated.

Expressive dimensions of pain catastrophizing: An observational study in adolescents with chronic pain

Investigated was the relationship between pain catastrophizing and pain intensity in adolescents suffering from chronic pain (n = 38) and the extent to which they expressed communicative pain and pain-related protective behaviours. Adolescents were observed on video performing a 2-Min Walk Test (2MWT). Behaviours were coded on videotape. The adolescents' verbalizations about the 2MWT were also rated by their parents. Analyses revealed that higher levels of catastrophic thinking about pain were associated with higher levels of facial pain expressions and verbalizations about their pain experience, beyond the effects of age, gender, pain duration and pain intensity. Pain-related protective behaviours did not vary with the adolescents' level of pain catastrophizing, but varied with pain intensity. The findings corroborate the functional distinctiveness of different types of pain behaviours. The results are discussed in terms of the processes linking (1) catastrophizing to communicative pain behaviours and (2) pain to pain-related protective behaviours.

Assessing pain by facial expression: facial expression as nexus

The experience of pain is often represented by changes in facial expression. Evidence of pain that is available from facial expression has been the subject of considerable scientific investigation. The present paper reviews the history of pain assessment via facial expression in the context of a model of pain expression as a nexus connecting internal experience with social influence. Evidence about the structure of facial expressions of pain across the lifespan is reviewed. Applications of facial assessment in the study of adult and pediatric pain are also reviewed, focusing on how such techniques facilitate the discovery and articulation of novel phenomena. Emerging applications of facial assessment in clinical settings are also described. Alternative techniques that have the potential to overcome barriers to the application of facial assessment arising out of its resource intensiveness are described and evaluated, including recent work on computer- based automatic assessment.

The relationship between high catastrophizing children's facial display of pain and parental judgment of their child's pain

The present study investigated the effect of the child's pain catastrophizing and self-reported pain upon the child's facial expression of pain and parental inferences of their child's pain. School children (n=62) experienced pain by taking part in a cold water procedure. Analyses revealed that more intense pain was associated with higher levels of facial pain expression in children who reported a low frequency of catastrophizing. In children with high pain catastrophizing, this relationship was not significant. A similar pattern was obtained for the pain inferences by the parent: pain intensity as reported by the child was positively related to pain inferences by the parent in children who reported a low frequency of catastrophizing, but such relationship was not significant for children with high catastrophizers. Further analyses revealed that when pain intensity was low, parents of high catastrophizing children judged the pain of their child to be higher than parents of low catastrophizing children. The implications of the findings are discussed in terms of the importance of assessing different dimensions of pain encoded in expression, different types of pain expression, and its differential effects upon others.

Sex differences in parent and child pain ratings during an experimental child pain task

Research in the field of pediatric pain has largely ignored the role of fathers in their children's pain experiences. The first objective of the present study was to examine the effect of the presence of mothers versus fathers on children's subjective ratings, facial expressions and physiological responses to acute pain. The second objective was to examine whether child and parent sex influence parents' proxy ratings of their children's pain. The final objective was to compare levels of agreement between mothers' and fathers' assessments of their children's pain. Participants included 73 children (37 boys, 36 girls), four to 12 years of age, along with 32 fathers and 41 mothers. Children undertook the cold pressor pain task while observed by one of their parents. During the task, the children's heart rates and facial expressions were recorded. Children provided self-reports and parents provided proxy reports of child pain intensity using the seven-point Faces Pain Scale. Neither child nor parent sex had a significant impact on children's subjective reports, facial expressions or heart rates in response to acute pain. Fathers gave their sons higher pain ratings than their daughters, whereas mothers' ratings of their sons' and daughters' pain did not differ. Kappa statistics and t tests revealed that fathers tended to be more accurate judges of their children's pain than mothers. Overall, this research highlights the importance of examining both parent and child sex differences in pediatric pain research.

Catastrophizing about their children's pain is related to higher parent-child congruency in pain ratings: an experimental investigation

Little is known about the variables that account for why parents underestimate the pain of their child. In the present experiment, the joint impact of parental catastrophizing about their child's pain and children's facial pain expressions was examined upon pain estimates of their child undergoing a pressure pain test. In line with previous research, parents underestimated their children's pain. Interestingly, it was found that pain was estimated as higher when the child showed more facial pain expressions and when parents catastrophized more about their child's pain. An intriguing finding was that catastrophizing about their child's pain was related to less parent-child incongruence in pain ratings. The discussion addresses the possible functions of catastrophizing of parents about their children's pain, and delineates avenues for future research.

Facial expression and pain assessment in the pediatric patient: the primal face of pain

PURPOSE

This paper aims to explore the role of facial expression in pediatric pain assessment. A comparison of tools employing facial expression methodology is presented. The concept of the primal face of pain (PFP) is introduced.

CONCLUSION

The PFP offers an explanation to the utility and deficiency of facial pain scales and facial expression in pain assessment.

PRACTICE IMPLICATIONS

The complexities of pain measurement should preclude the clinical application of untested instruments. For reported tools, a careful evaluation of the psychometric properties and the clinical context must precede application. The concept of the PFP warns against the application of facial pain scales as proxy measures in their intended population. Reliance on facial expression to assess pain in the school-age child is imprecise.

Is there a Primal Face of Pain? A methodology answer

Pain assessment is of high priority in the clinical setting. Facial Pain Scales (FPSs) are pain assessment tools generally used with school-aged children. The implicit theoretical bases for the success of FPSs have seldom been explored. Explanations why and how FPSs work (or do not work) have not been addressed. We support the existence of a universal pain expression--the Primal Face of Pain (PFP), which is present at birth, evolved in nature, and modulated through sociocultural factors. We propose it to be key in understanding the applicability of FPSs. We present here the design of a computer-assisted descriptive study that will observe, quantify and model the PFP as present in newborns. Measurement of the PFP will lead to exploration of the theoretical consequences of its existence, particularly as related to pediatric pain assessment and the valid use of FPSs. Further, this work can lay a foundation for the development of a new generation of FPSs.

The effects of parental presence upon the facial expression of pain: the moderating role of child pain catastrophizing

This experiment investigated the effects of child catastrophic thinking and parental presence on the facial expressions of children when experiencing pain. School children experienced pressure pain in either one of two conditions: (1) when observed by a parent (n=53 children and their parent), or (2) when observed by an adult stranger (n=31 children). Analyses revealed that children showed more facial pain expression in the presence of their parent than in the presence of the stranger. This effect was, however, only found for children with infrequent catastrophic thoughts about pain. Children who have frequent catastrophic thoughts expressed high pain regardless of who they believed was observing them. Results are discussed in terms of the social consequences of pain catastrophizing, and the variables contributing to the expression or suppression of pain display in children and its impact upon others.

Evidence-based assessment of pediatric pain

OBJECTIVE

To conduct an evidence-based review of pediatric pain measures.

METHODS

Seventeen measures were examined, spanning pain intensity self-report, questionnaires and diaries, and behavioral observations. Measures were classified as "Well-established," "Approaching well-established," or "Promising" according to established criteria. Information was highlighted to help professionals evaluate the instruments for particular purposes (e.g., research, clinical work).

RESULTS

Eleven measures met criteria for "Well-established," six "Approaching well-established," and zero were classified as "Promising."

CONCLUSIONS

There are a number of strong measures for assessing children's pain, which allows professionals options to meet their particular needs. Future directions in pain assessment are identified, such as highlighting culture and the impact of pain on functioning. This review examines the research and characteristics of some of the commonly used pain tools in hopes that the reader will be able to use this evidence-based approach and the information in future selection of assessment devices for pediatric pain.

Effects of preparatory information and distraction on children's cold-pressor pain outcomes: A randomized controlled trial

This experimental study investigated whether preparatory sensory information was more effective in managing children's pain when coupled with a distraction technique. Seventy-eight children aged 7-12 years were randomly allocated to 1 of 4 experimental conditions. They were given either a detailed sensory description of an imminent painful event (cold-pressor arm immersion in 10 degrees C water) or control instructions lacking sensory information. During the cold-pressor task, half the sample received an imagery-based distraction intervention. Pain measures included immersion tolerance, self-reported pain intensity, and facial pain responses. Self-reported coping style was assessed using the Pain Coping Questionnaire [Reid, G. J., Gilbert, C. A., & McGrath, P. J. (1998). The pain coping questionnaire: Preliminary validation. Pain, 76, 83-96]. The effects of information provision interacted with distraction for pain intensity but not pain tolerance. Children given sensory preparation reported less intense pain when this was coupled with distraction than when it was not. Children with a distraction-based coping style showed greater tolerance when assigned to a condition congruent with their coping style. These findings suggest ways to better prepare children for painful medical procedures.

Systematic review of observational (behavioral) measures of pain for children and adolescents aged 3 to 18 years

Observational (behavioral) scales of pain for children aged 3 to 18 years were systematically reviewed to identify those recommended as outcome measures in clinical trials. This review was commissioned by the Pediatric Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (www.immpact.org). In an extensive literature search, 20 observational pain scales were identified for review including behavior checklists, behavior rating scales, and global rating scales. These scales varied in their reliance on time sampling and inclusion of physiological items, facial and postural items, as well as their inclusion of multiple dimensions of assessment (e.g., pain and distress). Each measure was evaluated based on its reported psychometric properties and clinical utility. Scales were judged to be indicated for use in specific acute pain contexts rather than for general use. Two scales were recommended for assessing pain intensity associated with medical procedures and other brief painful events. Two scales were recommended for post-operative pain assessment, one for use in hospital and the other at home. Another scale was recommended for use in critical care. Finally, two scales were recommended for assessing pain-related distress or fear. No observational measures were recommended for assessing chronic or recurrent pain because the overt behavioral signs of chronic pain tend to habituate or dissipate as time passes, making them difficult to observe reliably. In conclusion, no single observational measure is broadly recommended for pain assessment across all contexts. Directions for further research and scale development are offered.

Machine recognition and representation of neonatal facial displays of acute pain

OBJECTIVE

It has been reported in medical literature that health care professionals have difficulty distinguishing a newborn's facial expressions of pain from facial reactions to other stimuli. Although a number of pain instruments have been developed to assist health professionals, studies demonstrate that health professionals are not entirely impartial in their assessment of pain and fail to capitalize on all the information exhibited in a newborn's facial displays. This study tackles these problems by applying three different state-of-the-art face classification techniques to the task of distinguishing a newborn's facial expressions of pain.

METHODS

The facial expressions of 26 neonates between the ages of 18 h and 3 days old were photographed experiencing the pain of a heel lance and a variety of stressors, including transport from one crib to another (a disturbance that can provoke crying that is not in response to pain), an air stimulus on the nose, and friction on the external lateral surface of the heel. Three face classification techniques, principal component analysis (PCA), linear discriminant analysis (LDA), and support vector machine (SVM), were used to classify the faces.

RESULTS

In our experiments, the best recognition rates of pain versus nonpain (88.00%), pain versus rest (94.62%), pain versus cry (80.00%), pain versus air puff (83.33%), and pain versus friction (93.00%) were obtained from an SVM with a polynomial kernel of degree 3. The SVM outperformed two commonly used methods in face classification: PCA and LDA, each using the L1 distance metric.

CONCLUSION

The results of this study indicate that the application of face classification techniques in pain assessment and management is a promising area of investigation.

Capturing postoperative pain responses in critically ill infants aged 0 to 9 months

OBJECTIVES

The purpose of this study was to describe physiologic and behavioral pain behaviors in postoperative critically ill infants. A secondary aim was to identify how these pain responses vary over time.

DESIGN

This observational study was conducted in the pediatric intensive care unit at two tertiary referral hospitals. Using ethological methods of observation, video recordings of postoperative infants were viewed to depict different situations of pain and no pain and were then coded using a reliable checklist.

PATIENTS

A total of 803 recorded segments were generated from recordings of five critically ill infants aged between 0 and 9 months who had undergone major surgery.

MEASUREMENTS AND MAIN RESULTS

There was an 82% agreement between the two coders. Multivariate analyses showed that physiologic responses differed only when adjusted for time. Significant decreases in systolic and diastolic arterial pressure (p < .001 and p = .036, respectively) were associated with postoperative pain exacerbated by painful procedures on day 2. On day 3, however, heart rate, arterial pressure (systolic, diastolic, and mean), and central venous pressure significantly increased (p < .05) in response to postoperative pain. Indicators included vertical stretch of the mouth, hand twitching, and jerky leg movements for postoperative pain and increase in respiratory distress, frown, eyes tightly closed, angular stretch of the mouth, silent or weak cry, jerky head movements, fist, pulling knees up, and spreading feet for postoperative pain exacerbated by painful stimuli.

CONCLUSIONS

Findings support the ability to capture different intensities of postoperative pain in critically ill infants beyond neonatal age. These pain indicators can be used for the development of a pain assessment tool for this group of infants.

Expression of Pain in Children With Autism

OBJECTIVES

Reduced pain sensitivity is widely reported to be a common feature of children with autism, yet this conclusion frequently has been based on anecdotal observations and questionable measures of pain. The aims of the study were to (1) characterize the behavioral response of children with autism experiencing a venepuncture using objective observational measures of pain and distress, (2) examine parents' assessments of pain behavior in children with and without autism, including comparison of the relationship of parental reports with behavioral measures, and (3) compare the behavioral reactions and parental assessments of children with autism with children without autism undergoing venepuncture.

METHODS

Pain reactions to the invasive procedure of venepuncture were videotaped, systematically described and compared in 21 children with autism (3-7 years old) and 22 nonimpaired children, the latter providing a chronological age and gender equivalent comparison group. Parents provided observer reports of pain, and facial activity was used as an objective behavioral measure of pain.

RESULTS

The children with autism displayed a significant facial pain reaction in response to the venepuncture procedure. There was a lack of concordance between parental reports of pain and observed pain responses for the children with autism. Behavioral responses of the children with autism were generally similar to the comparison group, except the substantial facial pain reactivity instigated by the venepuncture in the children with autism exceeded that displayed by the nonimpaired comparison children. Parent reports of pain severity did not differ between the autism and comparison groups. The degree of concordance between parental report and observed pain responses was consistently better for the comparison group.

DISCUSSION

The findings demonstrate that children with autism display a significant behavioral reaction in response to a painful stimulus, and these findings are in sharp contrast to the prevailing beliefs of pain insensitivity described in the literature to date. The findings also raise questions about the appropriateness of parental global report as an assessment tool for pain in children with autism.

The challenges of pain measurement in critically ill young children: A comprehensive review

This article addresses the issues in measuring pain in critically ill children, provides a comprehensive review of the pain measures for children aged between 0 and 3 years, and discusses their applicability to this group of children. When children are critically ill, pain can only exacerbate the stress response that already exists, to the extent that homeostasis cannot be maintained. Severity of illness is thus likely to affect physiologic and behavioural pain responses that would normally be demonstrated in healthy children. The problem of differentiating pain from other constructs adds to the complexity of assessing pain in non-verbal children. A pain measure to be useful clinically must be adapted to the developmental age of the target population. Search of electronic databases and other electronic sources was supplemented by hand review of relevant journals to identify published and unpublished pain measures for use in children aged between 0 and 3 years. Twenty eight pain measures were identified in the literature; 11 for neonates only, 11 for children aged between 0 and 3 years, and six for children more than 12 months. These measures vary in relation to their psychometric properties, clinical utility and the context in which the study was performed. These measures may not be suitable for the critically ill young child, because the items included were derived from observations of healthy or moderately sick children, and may not reflect pain behaviour in those who are critically ill. It is therefore recommended to develop new pain scales for this population of compromised children.

Neonatal Facial Coding System for Assessing Postoperative Pain in Infants: Item Reduction is Valid and Feasible

OBJECTIVE

The objectives of this study were to: (1). evaluate the validity of the Neonatal Facial Coding System (NFCS) for assessment of postoperative pain and (2). explore whether the number of NFCS facial actions could be reduced for assessing postoperative pain.

DESIGN

Prospective, observational study.

PATIENTS

Thirty-seven children (0-18 months old) undergoing major abdominal or thoracic surgery.

OUTCOME MEASURES

The outcome measures were the NFCS, COMFORT "behavior" scale, and a Visual Analog Scale (VAS), as well as heart rate, blood pressure, and catecholamine and morphine plasma concentrations. At 3-hour intervals during the first 24 hours after surgery, nurses recorded the children's heart rates and blood pressures and assigned COMFORT "behavior" and VAS scores. Simultaneously we videotaped the children's faces for NFCS coding. Plasma concentrations of catecholamine, morphine, and its metabolite M6G were determined just after surgery, and at 6, 12, and 24 hours postoperatively.

RESULTS

All 10 NFCS items were combined into a single index of pain. This index was significantly associated with COMFORT "behavior" and VAS scores, and with heart rate and blood pressure, but not with catecholamine, morphine, or M6G plasma concentrations. Multidimensional scaling revealed that brow bulge, eye squeeze, nasolabial furrow, horizontal mouth stretch, and taut tongue could be combined into a reduced measure of pain. The remaining items were not interrelated. This reduced NFCS measure was also significantly associated with COMFORT "behavior" and VAS scores, and with heart rate and blood pressure, but not with the catecholamine, morphine, or M6G plasma concentrations.

CONCLUSION

This study demonstrates that the NFCS is a reliable, feasible, and valid tool for assessing postoperative pain. The reduction of the NFCS to 5 items increases the specificity for pain assessment without reducing the sensitivity and validity for detecting changes in pain.