Contextual factors associated with pain response of preterm infants to heel-stick procedures

A child in pain: A psychologist’s perspective on changing priorities in scientific understanding and clinical care

My research and clinical career followed a trajectory of increasing appreciation for the importance of social factors as determinants of pain experience and expression. The social contexts of children’s lives determine whether infants and children are exposed to pain, how socialization in family and ethnocultural contexts lead to pain as a social experience, comprised of thoughts and feelings as well as sensory input, how others shape pain experience and expression, less so for automatic/reflexive features than purposeful representations, and how other's appraisals of children’s pain reflect the observer's unique background and capacities for intervening in the child’s interests. A greater understanding of the social dimensions of pain, as reflected in the social communication model of pain, would support innovation of psychological and social interventions.

Acute pain measured with the modified Bernese Pain Scale for Neonates is influenced by individual contextual factors

BACKGROUND

Individual contextual factors like gestational age (GA) or previous painful experiences have an influence on neonates' pain responses and may lead to inaccurate pain assessment when not appropriately considered.

OBJECTIVES

We set out to determine the influence of individual contextual factors on variability in pain response in neonates, measured with the modified Bernese Pain Scale for Neonates (BPSN), and, if necessary, to incorporate relevant individual factors into a revised version of the BPSN.

METHODS

We videotaped 154 full-term and preterm neonates of different GAs during 1-5 capillary heel sticks in their first 14 days of life. For each heel stick, we produced three video sequences: baseline, heel stick, and recovery. The randomized sequences were rated on the BPSN by five blinded nurses. Individual contextual factors were retrospectively extracted from patient charts and from the video recordings. We analysed the data in single and multiple linear mixed models.

RESULTS

Premature birth (b = -0.721), caffeine (b = -0.302), and the behavioural states quiet and awake (b = -0.283), active and asleep (b = -0.158), and quiet and asleep (b = -0.498) were associated with changes in behavioural pain scores. Premature birth (b = -0.232), mechanical ventilation (b = -0.196), and duration of the heel stick procedure (b = 0.0004) were associated with changes in physiological pain scores. Premature birth (b = -0.907), Caffeine (b = -0.402), the behavioural states quiet and awake (b = -0.274), and quiet and asleep (b = -0.459), and duration of the heel stick procedure (b = 0.001) were associated with changes in the modified BPSN total scores.

CONCLUSIONS

Postmenstrual age, behavioural state, caffeine, and ventilation status have an influence on neonates' pain response and should be incorporated in the revised BPSN to enhance clinical pain assessment in neonates with different GAs.

SIGNIFICANCE

We identified individual contextual factors associated with dampened pain response in neonates and will incorporate them into a revised version of the Bernese Pain Scale for Neonates to provide clinicians with a tool they can use to more accurately assess and manage pain in this vulnerable population.

The influence of gestational age in the psychometric testing of the Bernese Pain Scale for Neonates

BACKGROUND

Assessing pain in neonates is challenging because full-term and preterm neonates of different gestational ages (GAs) have widely varied reactions to pain. We validated the Bernese Pain Scale for Neonates (BPSN) by testing its use among a large sample of neonates that represented all GAs.

METHODS

In this prospective multisite validation study, we assessed 154 neonates between 24 2/7 and 41 4/7 weeks GA, based on the results of 1-5 capillary heel sticks in their first 14 days of life. From each heel stick, we produced three video sequences: baseline; heel stick; and, recovery. Five blinded nurses rated neonates' pain responses according to the BPSN. The underlying factor structure of the BPSN, interrater reliability, concurrent validity with the Premature Infant Pain Profile-Revised (PIPP-R), construct validity, sensitivity and specificity, and the relationship between behavioural and physiological indicators were explored. We considered GA and gender as individual contextual factors.

RESULTS

The factor analyses resulted in a model where the following behaviours best fit the data: crying; facial expression; and, posture. Pain scores for these behavioural items increased on average more than 1 point during the heel stick phases compared to the baseline and recovery phases (p < 0.001). Among physiological items, heart rate was more sensitive to pain than oxygen saturation. Heart rate averaged 0.646 points higher during the heel stick than the recovery phases (p < 0.001). GA increased along with pain scores: for every additional week of gestation, the average increase of behavioural pain score was 0.063 points (SE = 0.01, t = 5.49); average heart rate increased 0.042 points (SE = 0.01, t = 6.15). Sensitivity and specificity analyses indicated that the cut-off should increase with GA. Modified BPSN showed good concurrent validity with the PIPP-R (r = 0.600-0.758, p < 0.001). Correlations between the modified behavioural subscale and the item heart rate were low (r = 0.102-0.379).

CONCLUSIONS

The modified BPSN that includes facial expression, crying, posture, and heart rate is a reliable and valid tool for assessing acute pain in full-term and preterm neonates, but our results suggest that adding different cut-off points for different GA-groups will improve the BPSN's clinical usefulness.

TRIAL REGISTRATION

The study was retrospectively registered in the database of Clinical Trial gov. Study ID-number: NCT 02749461 . Registration date: 12 April 2016.

Randomised crossover trial showed that using breast milk or sucrose provided the same analgesic effect in preterm infants of at least 28 weeks

AIM

Repeated, ongoing exposure to pain influences the growth, cognitive and motor functions, behaviour, personality and neurodevelopment of preterm infants. We compared the analgesic effects of expressed breast milk (EBM) and 24% oral sucrose on preterm neonates during venipuncture.

METHODS

This multicentre randomised, noninferiority, crossover trial focused on five neonatal university units in Madrid, Spain, from October 2013 to October 2014. It comprised 66 preterm infants born at less than 37 weeks and randomly split into two groups. They received either EBM or sucrose two minutes before venepuncture, together with nonnutritive sucking and swaddling, then the opposite procedure at a later point. Pain was measured with the premature infant pain profile (PIPP) and crying was also measured.

RESULTS

There were no statistically significant differences between the groups. The PIPP scores were seven (4-9) with breast milk and six (4-8.25) with sucrose (p = 0.28). The 11 infants born at under 28 weeks of age showed higher median scores of nine (9-14) for breast milk and four (4-7) for sucrose (p = 0.009).

CONCLUSION

EBM and 24% sucrose had the same analgesic effect during venipuncture in most of the preterm neonates, but sucrose worked better in extremely preterm infants.

Individual contextual factors in the validation of the Bernese pain scale for neonates: protocol for a prospective observational study

Background

The Bernese Pain Scale for Neonates (BPSN) is a multidimensional pain assessment tool that is already widely used in clinical settings in the German speaking areas of Europe. Recent findings indicate that pain responses in preterm neonates are influenced by individual contextual factors, such as gestational age (GA), gender and the number of painful procedures experienced. Currently, the BPSN does not consider individual contextual factors. Therefore, the aim of this study is the validation of the BPSN using a large sample of neonates with different GAs. Furthermore, the influence of individual contextual factors on the variability in pain reactions across GA groups will be explored. The results will be used for a modification of the BPSN to account for individual contextual factors in future clinical pain assessment in neonates.

Methods and design

This prospective multisite validation study with a repeated measures design will take place in three university hospital neonatal intensive care units (NICUs) in Switzerland (Bern, Basel and Zurich). To examine the impact of GA on pain responses and their variability, the infants will be stratified into six GA groups ranging from 24 0/7 to 42 0/7. Among preterm infants, 2–5 routine capillary heel sticks within the first 14 days of life, and among full-term infants, two heel sticks during the first days of life will be documented. For each heel stick, measurements will be video recorded for each of three phases: baseline, heel stick, and recovery. The infants’ pain responses will be rated according to the BPSN by five nurses who are blinded as to the number of each heel stick and as to the measurement phases. Individual contextual factors of interest will be extracted from patient charts.

Discussion

Understanding and considering the influence of individual contextual factors on pain responses in a revised version of the BPSN will help the clinical staff to more appropriately assess pain in neonates, particularly preterm neonates hospitalized in NICUs. Pain assessment is a first step toward appropriate and efficient pain management, which itself is an important factor in later motor and cognitive development in this vulnerable patient population.

Trial registration

The study is registered in the database of Clinical Trial gov. Study ID-number: NCT 02749461. Registration date: 12 April 2016.

Preterm infants exhibited less pain during a heel stick when they were played the same music their mothers listened to during pregnancy

AIM

Playing music during painful procedures has shown inconsistent benefits for preterm infants. This study observed preterm infants during a heel stick procedure to assess whether listening to the music their mothers listened to during pregnancy had any impact on their pain and physiological and behavioural parameters.

METHODS

We randomly exposed 42 preterm infants, with a mean gestational age of 31.8 ± 2.79 weeks, to the music their mothers listened to during pregnancy, recorded lullabies and no music, before, during and after a heel stick. Pain responses were measured using the Neonatal Pain, Agitation and Sedation Scale (N-PASS), and physiological and behavioural responses were recorded by a nurse blinded to the intervention.

RESULTS

N-PASS pain scores were lowest during mothers' music, with a mean of 1.40 (±1.28), compared to 2.33 (±1.64) for no music and 1.62 (±2.27) for the lullabies [F(3/121) = 4.86, p = 0.009]. Physiological parameters were not significantly different between the conditions. During the mothers' music, infants spent more time in a quiet alert state, with a significant decrease in their respiratory rates.

CONCLUSION

The music mothers listened to during pregnancy was more beneficial for preterm infants, as it decreased pain and improved behavioural states during a heel stick.

Development of Accumulated Pain/Stressor Scale (APSS) in NICUs: A National Survey

High-risk neonates experience numerous painful/stressful procedures daily in neonatal intensive care units (NICUs). Accumulated pain and stress have a detrimental impact on infants' neurodevelopment. Few valid tools are available to measure accumulated pain/stressors among NICU infants. The aim of this study was to obtain nurses' perceptions about severity and acuity levels regarding each painful/stressful procedure that infants may experience in the NICU. The data will support developing a new instrument, the Accumulated Pain/Stressor Scale (APSS) in NICUs. A nationwide online survey was conducted through the U.S. National Association of Neonatal Nurses membership. Respondents were asked to rate the perceived severity of pain/stress associated with 68 procedures using a 5-point Likert scale and to categorize pain/stress as acute or chronic. Modal values were used to determine summary rankings among the procedures. Eighty-four neonatal nurses completed the survey. Among 68 procedures, nearly all were rated as painful/stressful to some degree. Five procedures (7%) had a modal value of five (extremely painful/stressful), nine (14%) had a value of four, 20 (29%) had a value of three, 30 (44%) a value of two, and four (6%) had a value of one (not painful/stressful). Forty-four procedures (65%) were perceived as acute, six (9%) as chronic, and 18 (26%) as both acute and chronic. Nurses' perceptions of pain severity and acuity regarding procedures in NICUs varied somewhat. Further studies are needed in developing and validating the scale. The development of the APSS can quantitatively measure the accumulated neonatal pain/stress.

Status of Neonatal Pain Assessment and Management in Jordan

Current pain assessment and management in neonates need to be fully described before neonatal pain care can be optimized. This study's purpose was to report neonatal nurses' knowledge, existing pain assessment practice, and pharmacological pain management of neonates in Jordan. A cross-sectional descriptive study was conducted. Eighteen neonatal intensive care units in Jordan were included in the study. One hundred eighty-four neonatal nurses participated. Questionnaires were distributed by and returned to the neonatal intensive care units' managers between June and August 2014. Descriptive and inferential statistics were used to present study results. Of 240 questionnaires distributed, 184 useable responses were returned. Nurses' knowledge regarding neonates' neurological development, nociception, and need for neonatal pain management was suboptimal. The analgesics most commonly used to treat neonatal pain were acetaminophen (52%) and lidocaine (45%). Benzodiazepines, phenobarbitone, and muscles relaxants were also used. Most nurses (54%-97%) reported that pain emanating from most painful procedures was never or rarely treated. Circumcision, lumbar punctures, and chest tube insertion were assigned the highest pain scores (≥9), but were rarely accompanied by analgesia. Pain assessment scales were more likely to be used, and procedural pain was more likely to be treated, in private hospitals than public hospitals. Neonates who require special care still suffer unnecessary pain that could be avoided and managed by following best practice recommendations. Disparities between developed and developing countries in quality of neonatal pain care appear to exist. Resources for education and routine care are needed to address these discrepancies.

Analgesia, nil or placebo to babies, in trials that test new analgesic treatments for procedural pain

This review assessed how often neonates in control groups experienced unnecessary pain during clinical trials involving procedural pain. We retrieved 45 studies in the 30 months up to June 2015 and found that in 29 (64%) the control babies received either placebos or no treatment. Placebos were used in 15/25 (60%) studies involving heel pricks and in 6/8 (75%) involving venepuncture.

CONCLUSION

Despite international guidelines, neonates included in control groups during painful procedures do not receive analgesia in the majority of cases. Several historical reasons can explain this, but in the light of present knowledge, this should not continue. Ethical committees are thereof invited since now to not permit clinical trials that do not explicitly rule out pain during treatments and journals are invited to not publish them.

Perceptions of health professionals on pain in extremely low gestational age infants

Extremely low gestational age infants (<28 weeks at birth) experience significant pain from repeated therapeutic procedures while hospitalized in the neonatal intensive care unit. As part of a program of research examining pain in preterm infants, we conducted a qualitatively driven mixed-methods design, supplemented with a qualitative and quantitative component, to understand how health care professionals (HCPs) assess and manage procedural pain for tiny and underdeveloped preterm infants. Fifty-nine HCPs from different disciplines across four tertiary-level neonatal units in Canada participated in individual or focus group interviews and completed a brief questionnaire. Four themes from the content analysis were (a) subtlety and unpredictability of pain indicators, (b) infant and caregiver attributes and contextual factors that influence pain response and practices, (c) the complex nature of pain assessment, and (d) uncertainty in the management of pain. The information gleaned from this study can assist in identifying gaps in knowledge and informing unit-based and organizational knowledge translation strategies for this vulnerable population.

Measurement of Acute Pain in Infants

Background:

The use of non-validated pain measurement tools to assess infant pain represents a serious iatrogenic threat to the developing neonatal nervous system. One partial explanation for this practice may be the contradictory empirical data from studies that use newborn pain management tools constructed for infants of different developmental stages or exposed to different environmental stressors.

Purpose:

The purpose of this review is to evaluate the evidence regarding the physiologic and behavioral variables that accurately assess and measure acute pain response in infants.

Methodology:

A literature search was conducted using PUBMED and CINAHL and the search terms infant, neonate/neonatal, newborn, pain, assessment, and measurement to identify peer-reviewed studies that examined the validity and reliability of behavioral and physiological variables used for investigation of infant pain. Ten articles were identified for critical review. Principal findings: Strong evidence supports the use of the behavioral variables of facial expressions and body movements and the physiologic variables of heart rate and oxygen saturation to assess acute pain in infants.

Conclusion:

It is incumbent upon researchers and clinical nurses to ensure the validity, reliability, and feasibility of pain measures, so that the outcomes of their investigations and interventions will be developmentally appropriate and effective pain management therapies.