Factors explaining lack of response to heel stick in preterm newborns

Behavioral and physiological pain structures of PIPP-R and parental stress: structural equation modeling approach

BACKGROUND

Although most non-acute pain assessment tools are multi-dimensional (behavioral and physiological measures) in their approach, the outputs of such tools are considered unidimensional. This study aimed to explore and determine the behavioral and physiological pain structures of Premature Infant Pain Profile-Revised (PIPP-R) for neonates and its association with parental stress.

METHODS

This cross-sectional study was conducted in 2022-2023 in Isfahan, Iran. We recruited 400 pre-term infants, i.e. with gestational age (GA) of less than 37weeks who were admitted to the NICU of educational hospitals. PIPP-R and Parental Stressor Scale: Neonatal Intensive Care Unit (PSS: NICU) were used for data gathering. The latent structures of pain and its association with parental stress were explored using latent variable modeling approach.

RESULTS

A two-factor model, i.e. behavioral and physiological pain factors, was extracted, explaining 65% of the total variance. The results of confirmatory factor analysis showed that the identified structures in the exploratory factor analysis could be nearly replicated (CFI = 0.99، TLI = 0.98, RMSEA = 0.001). Behavioral pain structure, independent from gestational age had a significant direct association with parental stress score (β = 0.005, SE = 0.002, p = 0.026).

CONCLUSIONS

The PIPP-R assesses both behavioral and physiological pain factors. We also found that behavioral pain factor was associated with parental stress.

IMPACT

These results may provide a potential clue for physicians, nurses, and parents to manage the pain in preterm infant. The PIPP-R scores in preterm infants consist of "Behavioral and Physiological" pain factors. Single dependence on behavioral indicators (such as facial expression) has some limitations. Multidimensional tools may be the optimal method in detecting pain in preterm infants. Parental stress can affect behavioral pain structure in preterm infants. Intensive care nurses play an effective role in reducing the parental stress and pain severity of these preterm infants by including the help of mothers in procedures and providing them with psychological support.

Clinical thresholds in pain-related facial activity linked to differences in cortical network activation in neonates

ABSTRACT

In neonates, a noxious stimulus elicits pain-related facial expression changes and distinct brain activity as measured by electroencephalography, but past research has revealed an inconsistent relationship between these responses. Facial activity is the most commonly used index of neonatal pain in clinical settings, with clinical thresholds determining if analgesia should be provided; however, we do not know if these thresholds are associated with differences in how the neonatal brain processes a noxious stimulus. The objective of this study was to examine whether subclinical vs clinically significant levels of pain-related facial activity are related to differences in the pattern of nociceptive brain activity in preterm and term neonates. We recorded whole-head electroencephalography and video in 78 neonates (0-14 days postnatal age) after a clinically required heel lance. Using an optimal constellation of Neonatal Facial Coding System actions (brow bulge, eye squeeze, and nasolabial furrow), we compared the serial network engagement (microstates) between neonates with and without clinically significant pain behaviour. Results revealed a sequence of nociceptive cortical network activation that was independent of pain-related behavior; however, a separate but interleaved sequence of early activity was related to the magnitude of the immediate behavioural response. Importantly, the degree of pain-related behavior is related to how the brain processes a stimulus and not simply the degree of cortical activation. This suggests that neonates who exhibit clinically significant pain behaviours process the stimulus differently and that neonatal pain-related behaviours reflect just a portion of the overall cortical pain response.

The role of time interval elimination on pain control of preterm infants by sucrose administration

PURPOSE

The 2-min time interval of sucrose administration given before minor painful procedures in preterm infants is based on a few limited studies. We aimed to assess availability of sucrose analgesia in emergency states of minor procedural pain by eliminating the 2-min time interval prior to heel lance in preterm infants. The primary outcome was Premature Infants Pain Profile-Revised (PIPP-R) at 30 and 60 s.

METHODS

Healthy 69 preterms undergoing a heel lance, who were assigned randomly to 1 of 2 groups, i.e., group I, with the 2-min time interval of per oral 24% sucrose given prior to heel lance, or group II, without a time interval of per oral 24% sucrose, were recruited. Premature Infants Pain Profile-Revised, crying incidence, duration, and heart rate at 30 and 60 s following heel lance were the outcome measures in this single-center, randomized, prospective study.

RESULTS

The 2 groups did not differ significantly in PIPP-R scores at 30 s (6.63 vs. 6.32, p = .578) and 60 s (5.80 vs. 5.38, p = .478). The crying incidence was similar between the 2 groups (p = .276). The median crying duration was 6 s (range: 1-13 s) in group I and 4.5 s (range: 1-18 s) in group II (p = .226). No significant differences in the heart rates between the 2 groups and the proportion of adverse events by time interval elimination were recorded.

CONCLUSIONS

Eliminating the time interval did not decrease the analgesic effect of orally administered 24% sucrose given prior to heel lance. In emergency states of minor procedural pain, eliminating the 2-min time interval following sucrose administration is safe and efficacious in preterm infants.

Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society-American Academy of Pain Medicine Pain Taxonomy Diagnostic Criteria for Acute Needle Pain

Needle procedures are among the most common causes of pain and distress for individuals seeking health care. While needle pain is especially problematic for children needle pain and associated fear also has significant impact on adults and can lead to avoidance of appropriate medical care. Currently there is not a standard definition of needle pain. A taxonomy, or classification system, for acute needle pain would aid research efforts and enhance clinical care. To meet this need, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks public-private partnership with the U.S. Food and Drug Administration, the American Pain Society, and the American Academy of Pain Medicine formed the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society-American Academy of Pain Medicine Pain Taxonomy initiative. One of the goals of this initiative was to develop taxonomies for acute pain disorders, including needle pain. To accomplish this, a working group of experts in needle pain was convened. Based on available literature and expert opinion, the working group used a 5-dimenional structure (diagnostic criteria, common features, modulating factors, impact and/or functional consequences, and putative mechanisms) to develop an acute pain taxonomy that is specific needle pain. As part of this, a set of 4 diagnostic criteria, with 2 modifiers to account for the influence of needle associated fear, are proposed to define the types of acute needle pain. PERSPECTIVE: This article presents a taxonomy for acute needle pain. This taxonomy could help to standardize definitions of acute pain in clinical studies of patients undergoing needle procedures.

Nurses' Perception of Preterm Infants' Pain and the Factors of Their Pain Assessment and Management

In the neonatal intensive care unit, preterm infants undergo many painful procedures. Although these can impair their neurodevelopment if not properly managed, only half of the painful procedures are optimally handled. This cross-sectional study aimed to evaluate nurses' perceptions of preterm infants' pain, to evaluate nurses' pain assessment and management practices, as well as to identify the individual and contextual factors that influence nurses' assessments and interventions for pain management. Secondary analyses, including a mixed-model analysis, were performed with data from a larger study (n = 202 nurses). Nurses were found to have attitudes and perceptions in favor of preterm infants' pain management, although they reported using few standardized instruments to assess pain. Nurses stated that they widely used sucrose, non-nutritive sucking, and positioning as pain management interventions, while skin-to-skin contact was rarely practiced. Nurses' attitudes and perceptions influenced their pain assessment practices, which predicted their implementation of interventions. Several contextual (country, level of care, and work shift) and individual factors (age, level of education, had a preterm infant, perceptions of family-centered care, and skin-to-skin contact) also predicted nurses' pain assessment and management practices.

Pharmacologic Analgesia and Sedation in Neonates

Chronic pain and agitation in neonatal life impact the developing brain. Oral sweet-tasting solutions should be used judiciously to mitigate behavioral responses to mild painful procedures, keeping in mind that the long-term impact is unknown. Rapidly acting opioids should be used as part of premedication cocktails for nonemergent endotracheal intubations. Continuous low-dose morphine or dexmedetomidine may be considered for preterm or term neonates exhibiting signs of stress during mechanical ventilation and therapeutic hypothermia, respectively. Further research is required regarding the pharmacokinetics, pharmacodynamics, safety, and efficacy of pharmacologic agents used to mitigate mild, moderate, and chronic pain and stress in neonates.

Premedication with Fentanyl for Less Invasive Surfactant Application (LISA): A Randomized Controlled Trial

INTRODUCTION

Currently, there is no consensus regarding analgesic premedication before the surfactant administration by less invasive surfactant application (LISA) procedure. In this randomized controlled trial, we compared the level of comfort of preterm infants receiving fentanyl as analgesic and sedative versus no fentanyl during LISA procedure.

METHODS

We randomized 34 preterm infants of 28+0-33+6 weeks of gestation with respiratory distress syndrome (RDS) within 6 h of birth to receive either fentanyl (1 μg/kg intravenous) or no premedication during surfactant administration by LISA procedure. Primary objective was to assess the proportion of preterm infants to be comfortable during the procedure [revised premature infant pain profile (R-PIPP) score ≤12] and secondarily complications occurring during the procedure, hemodynamically significant patent ductus arteriosus (hsPDA), intraventricular hemorrhage (IVH) (≥ grade 3), bronchopulmonary dysplasia (BPD) and composite outcome of BPD/mortality.

RESULTS

Proportion of preterm infants with a R-PIPP score ≤12 during LISA was significantly higher in the fentanyl group [15/17 (88.23%) vs. 8/17 (47.05%); p value 0.025]. There were no differences in secondary outcome parameters.

CONCLUSION

Low-dose fentanyl during LISA procedure resulted in more comfort in preterm infants and without increased complication of both the LISA procedure and fentanyl administration. Further studies are needed to determine the safest and most effective pharmacologic measures to prevent pain and discomfort during LISA.

Quantifying the pharmacodynamics of morphine in the treatment of postoperative pain in preverbal children

While the pharmacokinetics of morphine in children have been studied extensively, little is known about the pharmacodynamics of morphine in this population. Here, we quantified the concentration‐effect relationship of morphine for postoperative pain in preverbal children between 0 and 3 years of age. For this, we applied item response theory modeling in the pharmacokinetic/pharmacodynamic analysis of COMFORT‐Behavior (COMFORT‐B) scale data from 2 previous clinical studies. In the model, we identified a sigmoid maximal efficacy model for the effect of morphine and found that in 26% of children, increasing morphine concentrations were not associated with lower pain scores (nonresponders to morphine up‐titration). In responders to morphine up‐titration, the COMFORT‐B score slowly decreases with increasing morphine concentrations at morphine concentrations >20 ng/mL. In nonresponding children, no decrease in COMFORT‐B score is expected. In general, lower baseline COMFORT‐B scores (2.1 points on average) in younger children (postnatal age <10.3 days) were found. Based on the model, we conclude that the percentage of children at a desirable COMFORT‐B score is maximized at a morphine concentration between 5 and 30 ng/mL for children aged <10 days, and between 5 and 40 ng/mL for children >10 days. These findings support a dosing regimen previously suggested by Krekels et al, which would put >95% of patients within this morphine target concentration range at steady state. Our modeling approach provides a promising platform for pharmacodynamic research of analgesics and sedatives in children.

Functional and diffusion MRI reveal the neurophysiological basis of neonates' noxious-stimulus evoked brain activity

Understanding the neurophysiology underlying neonatal responses to noxious stimulation is central to improving early life pain management. In this neonatal multimodal MRI study, we use resting-state and diffusion MRI to investigate inter-individual variability in noxious-stimulus evoked brain activity. We observe that cerebral haemodynamic responses to experimental noxious stimulation can be predicted from separately acquired resting-state brain activity (n = 18). Applying this prediction model to independent Developing Human Connectome Project data (n = 215), we identify negative associations between predicted noxious-stimulus evoked responses and white matter mean diffusivity. These associations are subsequently confirmed in the original noxious stimulation paradigm dataset, validating the prediction model. Here, we observe that noxious-stimulus evoked brain activity in healthy neonates is coupled to resting-state activity and white matter microstructure, that neural features can be used to predict responses to noxious stimulation, and that the dHCP dataset could be utilised for future exploratory research of early life pain system neurophysiology.

Quantification of neonatal procedural pain severity: a platform for estimating total pain burden in individual infants

There is increasing evidence that long-term outcomes for infants born prematurely are adversely affected by repeated exposure to noxious procedures. These interventions vary widely, for example, in the extent of damage caused and duration. Neonatal intensive care unit (NICU) procedures are therefore likely to each contribute differently to the overall pain burden of individual neonates, ultimately having a different impact on their development. For researchers to quantify the procedural pain burden experienced by infants on NICU, we aimed to estimate the pain severity of common NICU procedures using published pain scores. We extracted pain scores over the first minute (pain reactivity) from the literature, using 59 randomized controlled trials for 15 different procedures. Hierarchical cluster analysis of average pain scores resulted in 5 discrete severity groups; mild (n = 1), mild to moderate (n = 3), moderate (n = 7), severe (n = 3), and very severe (n = 1). The estimate of the severity of individual procedures provided new insight into infant pain reactivity which is not always directly related to the invasiveness and duration of a procedure; thus, both heel lance and skin tape removal are moderately painful procedures. This estimate of procedural pain severity, based on pain reactivity scores, provides a novel platform for retrospective quantification of an individual neonate's pain burden due to NICU procedures. The addition of measures that reflect the recovery from each procedure, such as brain activity and behavioural regulation, would further improve estimates of the pain burden of neonatal intensive care.

Neonatal pain: A journey spanning three decades

From 1980 into present day, 2020, the evolution of neonatal pain research is told as a journey by one researcher, Celeste Johnston. At the beginning of her work, there was essentially no interest or work in the area. She was fortunate to be led into the area by a clinical problem: how to determine the amount of pain babies in the NICU were experiencing. That question resulted in over three decades of work with neonates. Measuring pain was the first challenge and is one that remains a focus of current research. Initially, the only choices for treating pain in neonates were either opioids or anesthetics, each with problems. Research on sweet taste and more recently on skin‐to‐skin contact has offered effective and safe options for procedural pain. Although progress has been made in the incidence of pain management in infants, it still is far less than it could be. Steps along the way of measurement, treatment, and knowledge utilization are chronicled by this researcher.

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.

Rapidly maturing fentanyl clearance in preterm neonates

BACKGROUND

Fentanyl is frequently used off-label in preterm newborns. Due to very limited pharmacokinetic and pharmacodynamic data, fentanyl dosing is mostly based on bodyweight. This study describes the maturation of the pharmacokinetics in preterm neonates born before 32 weeks of gestation.

METHODS

442 plasma samples from 98 preterm neonates (median gestational age: 26.9 (range 23.9-31.9) weeks, postnatal age: 3 (range 0-68) days, bodyweight 1.00 (range 0.39-2.37) kg) were collected in an opportunistic trial and fentanyl plasma levels were determined. NONMEM V.7.3 was used to develop a population pharmacokinetic model and to perform simulations.

RESULTS

Fentanyl pharmacokinetics was best described by a two-compartment model. A pronounced non-linear influence of postnatal and gestational age on clearance was identified. Clearance (L/hour/kg) increased threefold, 1.3-fold and 1.01-fold in the first, second and third weeks of life, respectively. In addition, clearance (L/hour/kg) was 1.4-fold and 1.7-fold higher in case of a gestational age of 28 and 31 weeks, respectively, compared with 25 weeks. Volume of distribution changed linearly with bodyweight and was 8.7 L/kg. To achieve similar exposure across the entire population, a continuous infusion (µg/kg/hour) dose should be reduced by 50% and 25% in preterm neonates with a postnatal age of 0-4 days and 5-9 days in comparison to 10 days and older.

CONCLUSION

Because of low clearance, bodyweight-based dosages may result in fentanyl accumulation in neonates with the lowest postnatal and gestational ages which may require dose reduction. Together with additional information on the pharmacodynamics, the results of this study can be used to guide dosing.

Multimodal pain assessment improves discrimination between noxious and non‐noxious stimuli in infants

Infants in neonatal intensive care units frequently experience clinically necessary painful procedures, which elicit a range of behavioral, physiological, and neurophysiological responses. However, the measurement of pain in this population is a challenge and no gold standard exists. The aim of this study was to investigate how noxious‐evoked changes in facial expression, reflex withdrawal, brain activity, heart rate, and oxygen saturation are related and to examine their accuracy in discriminating between noxious and non‐noxious stimuli. In 109 infants who received a clinically required heel lance and a control non‐noxious stimulus, we investigated whether combining responses across each modality, or including multiple measures from within each modality improves our ability to discriminate the noxious and non‐noxious stimuli. A random forest algorithm was used to build data‐driven models to discriminate between the noxious and non‐noxious stimuli in a training set which were then validated in a test set of independent infants. Measures within each modality were highly correlated, while different modalities showed less association. The model combining information across all modalities had good discriminative ability (accuracy of 0.81 in identifying noxious and non‐noxious stimuli), which was higher than the discriminative power of the models built from individual modalities. This demonstrates the importance of including multiple modalities in the assessment of infant pain.

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.

Nociceptive brain activity as a measure of analgesic efficacy in infants

Pain in infants is undertreated and poorly understood, representing a major clinical problem. In part, this is due to our inability to objectively measure pain in nonverbal populations. We present and validate an electroencephalography-based measure of infant nociceptive brain activity that is evoked by acute noxious stimulation and is sensitive to analgesic modulation. This measure should be valuable both for mechanistic investigations and for testing analgesic efficacy in the infant population.

Clinical trial designs and models for analgesic medications for acute pain in neonates, infants, toddlers, children, and adolescents: ACTTION recommendations

Clinical trials to test the safety and efficacy of analgesics across all pediatric age cohorts are needed to avoid inappropriate extrapolation of adult data to children. However, the selection of acute pain models and trial design attributes to maximize assay sensitivity, by pediatric age cohort, remains problematic. Acute pain models used for drug treatment trials in adults are not directly applicable to the pediatric age cohorts-neonates, infants, toddlers, children, and adolescents. Developmental maturation of metabolic enzymes in infants and children must be taken into consideration when designing trials to test analgesic treatments for acute pain. Assessment tools based on the levels of cognitive maturation and behavioral repertoire must be selected as outcome measures. Models and designs of clinical trials of analgesic medications used in the treatment of acute pain in neonates, infants, toddlers, children, and adolescents were reviewed and discussed at an Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) Pediatric Pain Research Consortium consensus meeting. Based on extensive reviews and continuing discussions, the authors recommend a number of acute pain clinical trial models and design attributes that have the potential to improve the study of analgesic medications in pediatric populations. Recommendations are also provided regarding additional research needed to support the use of other acute pain models across pediatric age cohorts.

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.

Comparison of Neonatal Pain, Agitation, and Sedation Scale with Premature Infant Pain Profile for the Assessment of Acute Prolonged Pain in Neonates on Assisted Ventilation: A Prospective Observational Study

AIM

This study aimed to compare Neonatal Pain, Agitation, and Sedation Scale (N-PASS) with Premature Infant Pain Profile (PIPP) for the assessment of acute prolonged pain in ventilated neonates.

METHODS

This study was conducted in two phases. In phase 1 of the study, we assessed whether neonates on assisted ventilation experienced acute prolonged pain. In phase 2, the aim was to compare N-PASS with PIPP for the assessment of acute prolonged pain in neonates on assisted ventilation..

DESIGN

This is a prospective observational study.

STUDY SETTING AND DURATION

This study was conducted at a tertiary care neonatal intensive care unit for 6 months.

INCLUSION CRITERIA

Neonates on assisted ventilation for >48 h were selected for this study.

EXCLUSION CRITERIA

Neonates with lethal congenital anomalies and severe encephalopathy were excluded from the study. N-PASS and PIPP tools were used to assess acute prolonged pain in ventilated neonates. Taking PIPP as gold standard and N-PASS as a new test, the correlation coefficient was calculated. The sensitivity, specificity, positive predictive value, and negative predictive value were also computed. The time taken to administer the tools was also computed.

RESULTS

The average PIPP score for ventilated neonates was 8.33. The correlation coefficient of N-PASS when compared to PIPP was 0.62. The average time taken to apply the N-PASS scale was 4.42 min as compared to 8.20 min for PIPP scale. In term neonates, the sensitivity, specificity, positive predictive value, and negative predictive value of N-PASS were 75%, 100%, 100%, and 60%, respectively. The corresponding values in preterm neonates were lesser.

CONCLUSIONS

The study proves that neonates on assisted ventilation experience acute prolonged pain. N-PASS is clinically reliable and valid to assess acute prolonged pain in ventilated term neonates. The N-PASS is quicker than PIPP in assessing acute prolonged pain in ventilated neonates.

FUTURE DIRECTIONS

The modified N-PASS tool (including the gestational age) should be developed.

Co-bedding in neonatal nursery for promoting growth and neurodevelopment in stable preterm twins

BACKGROUND

The increased birth rate of twins during recent decades and the improved prognosis of preterm infants have resulted in the need to explore measures that could optimize their growth and neurodevelopmental outcomes. It has been postulated that co-bedding simulates twins' intrauterine experiences in which co-regulatory behaviors between them are observed. These behaviors are proposed to benefit twins by reducing their stress, which may promote growth and development. However, in practice, uncertainty surrounds the benefit-risk profile of co-bedding.

OBJECTIVES

We aimed to assess the effectiveness of co-bedding compared with separate (individual) care for stable preterm twins in the neonatal nursery in promoting growth and neurodevelopment and reducing short- and long-term morbidities, and to determine whether co-bedding is associated with significant adverse effects.As secondary objectives, we sought to evaluate effects of co-bedding via the following subgroup analyses: twin pairs with different weight ranges (very low birth weight [VLBW] < 1500 grams vs non-VLBW), twins with versus without significant growth discordance at birth, preterm versus borderline preterm twins, twins co-bedded in incubator versus cot at study entry, and twins randomized by twin pair versus neonatal unit.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group (CNRG). We used keywords and medical subject headings (MeSH) to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2), MEDLINE (via PubMed), EMBASE (hosted by EBSCOHOST), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and references cited in our short-listed articles, up to February 29, 2016.

SELECTION CRITERIA

We included randomized controlled trials with randomization by twin pair and/or by neonatal unit. We excluded cross-over studies.

DATA COLLECTION AND ANALYSIS

We extracted data using standard methods of the CNRG. Two review authors independently assessed the relevance and risk of bias of retrieved records. We contacted the authors of included studies to request important information missing from their published papers. We expressed our results using risk ratios (RRs) and mean differences (MDs) when appropriate, along with 95% confidence intervals (95% CIs). We adjusted the unit of analysis from individual infants to twin pairs by averaging measurements for each twin pair (continuous outcomes) or by counting outcomes as positive if developed by either twin (dichotomous outcomes).

MAIN RESULTS

Six studies met the inclusion criteria; however, only five studies provided data for analysis. Four of the six included studies were small and had significant limitations in design. As each study reported outcomes differently, data for most outcomes were effectively contributed by a single study. Study authors reported no differences between co-bedded twins and twins receiving separate care in terms of rate of weight gain (MD 0.20 grams/kg/d, 95% CI -1.60 to 2.00; one study; 18 pairs of twins; evidence of low quality); apnea, bradycardia, and desaturation (A/B/D) episodes (RR 0.85, 95% CI 0.18 to 4.05; one study; 62 pairs of twins; evidence of low quality); episodes in co-regulated states (MD 0.96, 95% CI -3.44 to 5.36; one study; three pairs of twins; evidence of very low quality); suspected or proven infection (RR 0.84, 95% CI 0.30 to 2.31; three studies; 65 pairs of twins; evidence of very low quality); length of hospital stay (MD -4.90 days, 95% CI -35.23 to 25.43; one study; three pairs of twins; evidence of very low quality); and parental satisfaction measured on a scale of 0 to 55 (MD -0.38, 95% CI -4.49 to 3.73; one study; nine pairs of twins; evidence of moderate quality). Although co-bedded twins appeared to have lower pain scores 30 seconds after heel lance on a scale of 0 to 21 (MD -0.96, 95% CI -1.68 to -0.23; two studies; 117 pairs of twins; I(2) = 75%; evidence of low quality), they had higher pain scores 90 seconds after the procedure (MD 1.00, 95% CI 0.14 to 1.86; one study; 62 pairs of twins). Substantial heterogeneity in the outcome of infant pain response after heel prick at 30 seconds post procedure and conflicting results at 30 and 90 seconds post procedure precluded clear conclusions.

AUTHORS' CONCLUSIONS

Evidence on the benefits and harms of co-bedding for stable preterm twins was insufficient to permit recommendations for practice. Future studies must be adequately powered to detect clinically important differences in growth and neurodevelopment. Researchers should assess harms such as infection, along with medication errors and caregiver satisfaction.

A Retrospective Examination of Prandial Aspiration in Preterm Infants

Purpose

We conducted this retrospective study to identify potential signs of aspiration in preterm infants based on crib-side nursing documentation.

Study Design and Methods

A total of 2,590 bottle-feedings were examined for signs of distress across 41 preterm infants who were referred for a swallowing evaluation. All infants underwent either a videofluoroscopic swallow study (VSS) or upper gastrointestinal study (GIS). Physiologic and behavioral warning signs were coded across feedings 10 days prior to the imaging study. Presence or absence of documented aspiration during VSS/GIS was coded for each infant.

Results

Distress signs were documented in seven percent of oral feeding attempts. Aspiration was more common when the crib-side nurse documented coughing (LR+, 8.77; 95% CI, .99–77.09), compromised oxygen saturation levels (LR+, 2.15; CI, .86–5.47), and tachypnea (LR+, 2.15; CI, .28–3.01) during bottle-feeding.

Clinical Implications

Evidence-based distress signs that signal increased suspicion for prandial aspiration will facilitate correct clinical judgments at crib-side. Early identification and prevention of prandial aspiration improves health outcomes for preterm infants.

The relationship between nociceptive brain activity, spinal reflex withdrawal and behaviour in newborn infants

Measuring infant pain is complicated by their inability to describe the experience. While nociceptive brain activity, reflex withdrawal and facial grimacing have been characterised, the relationship between these activity patterns has not been examined. As cortical and spinally mediated activity is developmentally regulated, it cannot be assumed that they are predictive of one another in the immature nervous system. Here, using a new experimental paradigm, we characterise the nociceptive-specific brain activity, spinal reflex withdrawal and behavioural activity following graded intensity noxious stimulation and clinical heel lancing in 30 term infants. We show that nociceptive-specific brain activity and nociceptive reflex withdrawal are graded with stimulus intensity (p < 0.001), significantly correlated (r = 0.53, p = 0.001) and elicited at an intensity that does not evoke changes in clinical pain scores (p = 0.55). The strong correlation between reflex withdrawal and nociceptive brain activity suggests that movement of the limb away from a noxious stimulus is a sensitive indication of nociceptive brain activity in term infants. This could underpin the development of new clinical pain assessment measures.

Effect of repeated Kangaroo Mother Care on repeated procedural pain in preterm infants: A randomized controlled trial

BACKGROUND

Preterm infants' repeated exposure to painful procedures may lead to negative consequences. Thus, non-pharmacological pain management is essential due to medication side effects. Kangaroo Mother Care, which aims at offering human care to neonates, has been established for the treatment of a single painful procedure, but the effectiveness of Kangaroo Mother Care across repeated painful procedures is unknown.

OBJECTIVE

To test the effectiveness of repeated Kangaroo Mother Care on repeated heel-stick pain in preterm neonates.

DESIGN

Randomized controlled trial.

SETTING

Level III Neonatal Intensive Care Unit at a large teaching hospital in northeast China.

METHOD

Preterm infants (gestational age less than 37 weeks) (n=80) were recruited and randomly assigned using a random table format to either an incubator group (n=40) or Kangaroo Mother Care group (n=40). Pain assessments were carried out during four routine heel stick procedures. For the first heel stick, preterm infants in each group received no intervention (routinely stayed in incubator). During the next three heel sticks, the infants in Kangaroo Mother Care group received heel sticks during Kangaroo Mother Care, while infants in the incubator group received heel sticks in incubator. The procedure of each heel stick included 3 phases: baseline, blood collection and recovery. Crying, grimacing and heart rate in response to pain were evaluated at each phase across four heel sticks by three trained independent observers who were blinded to the purpose of the study. Data were analyzed by analysis of variance (ANOVA), with repeated measures at different evaluation phases of heel stick.

RESULTS

75 preterm infants completed the protocol. Between-group comparison revealed that preterm infants' heart rate was significantly lower, and the duration of crying and facial grimacing were both significantly shorter in the Kangaroo Mother Care group (n=38) than the incubator group (n=37) from the blood collection phase to recovery phase during repeated heel sticks. No significant within-group difference was found in heart rate between the baseline phase and recovery phase through repeated heel sticks for Kangaroo Mother Care group. In contrast, the incubator group experienced significant within group differences in heart rate between baseline and recovery through repeated heel sticks.

CONCLUSION

The effect of repeated Kangaroo Mother Care analgesia remains stable in preterm infants over repeated painful procedures. Given the many invasive procedures that are part of clinical care in preterm infants and most mothers preferred to provide comfort for their infants during painful procedures, Kangaroo Mother Care may be a safe analgesic alternative in preterm infants in whom it is feasible.

The Neonatal Pain, Agitation and Sedation Scale and the bedside nurse's assessment of neonates

OBJECTIVE

To determine the reliability of an objective measure of pain, agitation and sedation using the Neonatal Pain, Agitation and Sedation Scale (N-PASS) compared with nursing bedside assessment.

STUDY DESIGN

Neonates admitted in neonatal intensive care unit over a 6-month period were eligible. Pain and sedation were assessed with N-PASS, and a subjective questionnaire was administered to the bedside nurse.

RESULT

A total of 218 neonates were eligible (median: gestational age 34.6 weeks, age at assessment 7 days). N-PASS pain score correlated significantly with both nurses' pain score (Spearman coefficient (r)=0.37; P<0.001) and agitation score (r=0.56; P<0.001). N-PASS sedation score correlated with nurses' sedation score (r=-0.39; P<0.001). Adjusting for gestational age, day of life, intrauterine drug exposure and use of high frequency ventilation only slightly attenuated the correlations (r=0.36, 0.55 and -0.31, respectively).

CONCLUSION

The N-PASS captures nursing assessment of pain, agitation and sedation in this broad population and provides a quantitative assessment of subjective descriptions that often drives patient therapy.

Evaluation of retinopathy of prematurity screening in reverse Kangaroo Mother Care: a pilot study

PURPOSE

To evaluate retinopathy of prematurity (ROP) screening practice in reverse Kangaroo Mother Care (R-KMC) with respect to stress and pain to the infant.

METHODS

In a pilot study we evaluated ROP screening practice in R-KMC in 20 babies at risk of ROP. The R-KMC differed from the conventional KMC with respect to the baby position where the baby lay supine on mother's chest. With the mother lying supine and the baby in R-KMC position, screening examinations were done with indirect ophthalmoscope. The outcome measures included stress (quantified by pulse, respiration, and oxygen saturation) and pain to the baby by observing facial expression (eye squeezing, crying, and brow bulge). The heart rate, respiratory rate, and SpO2 (%) were compared before and immediately after the procedure using paired t-test.

RESULT

Mean (±SD) gestational age and birth weight were 30.8±2.3 weeks and 1362.5±253.9 g, respectively. During examination in R- KMC position 8 babies (40%) were completely relaxed (no eye squeezing and crying), 10 (50%) were partially relaxed (no brow bulge) and 2 babies (10%) were not relaxed. A change in heart and respiration rate both by 10 per minute was recorded in 12 (60%) and 10 (50%) babies, respectively. Five babies (25%) had reduction in blood oxygen concentration below 92%. The majority of the mothers (19 of 20) were relaxed.

CONCLUSION

ROP screening in R-KMC can be a baby friendly screening practice with respect to stress and pain to the infant and needs further evaluation in a larger cohort.

Pain management in newborns

As a standard of care for preterm/term newborns effective pain management may improve their clinical and neurodevelopmental outcomes. Neonatal pain is assessed using context-specific, validated, and objective pain methods, despite the limitations of currently available tools. Therapeutic approaches reducing invasive procedures and using pharmacologic, behavioral, or environmental measures are used to manage neonatal pain. Nonpharmacologic approaches like kangaroo care, facilitated tucking, non-nutritive sucking, sucrose, and others can be used for procedural pain or adjunctive therapy. Local/topical anesthetics, opioids, NSAIDs/acetaminophen and other sedative/anesthetic agents can be incorporated into NICU protocols for managing moderate/severe pain or distress in all newborns.

Validation of the Premature Infant Pain Profile-Revised (PIPP-R)

OBJECTIVES

To examine the construct validity, inter-rater reliability, and feasibility of the Premature Infant Pain Profile-Revised in infants of varying gestational ages, diagnoses, and procedures.

METHODS

A prospective cross-over study with infants in three gestational age groups (26-31, 32-36, and ≥37 weeks) at three university-affiliated Neonatal Intensive Care Units in Canada. One hundred and ninety five bedside nurses and expert raters rated 202 hospitalized infants' pain during scheduled procedures using the measure. An expert rater and a nurse independently assessed infants' pain scores, using the Premature Infant Pain Profile-Revised, during 246 scheduled pairs of painful and non-painful procedures in the 202 infants. Nurses also completed a feasibility survey on using the measure in a clinical setting. To establish construct validity, pain scores were computed during painful and non-painful procedures. Inter-rater reliability between pain experts and nurses was calculated. A 5-point Likert scale was used to measure feasibility in terms of clarity, ease of use, and time to complete.

RESULTS

Irrespective of gestational age, Premature Infant Pain Profile-Revised scores were significantly higher during painful procedures (mean 6.7 [SD 3.0]) compared to non-painful procedures (mean 4.8 [SD 2.9]). There was a high degree of correlation between nurses' and experts' ratings for painful (all R(2)=0.92, p<0.001) and non-painful (all R(2)=0.87, p<0.001) procedures. Mean scores on all feasibility indicators were equal to or higher than 3.8.

DISCUSSION

The Premature Infant Pain Profile Revised has beginning construct validation, inter-rater reliability, and is considered feasible by clinicians. Concurrent validation studies should be considered.

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.

Development of a scale for estimating procedural distress in the newborn intensive care unit: the Procedural Load Index

BACKGROUND

Infants in the newborn intensive care unit (NICU) are exposed to routine procedures that often cause distress and carry a negative burden or load on the infant's neurodevelopment.

AIM

A ratio level index is introduced to estimate procedural load so as to begin to develop a system to monitor the intensity of distress associated with common NICU procedures.

STUDY DESIGN

Two psychophysical methods, magnitude estimation (ME) and the general labeled magnitude scale (gLMS) were used to survey 86 clinicians via the internet to estimate the distress associated with 55 common NICU procedures.

RESULTS

gLMS and ME estimations correlated highly across all procedures (r = 0.97). gLMS values were used to derive the procedural load index (PLI) as a ratio level estimation of procedural distress.

CONCLUSION

The PLI ranks and differentiates distress among common NICU procedures more precisely than current tools. This methodology, if correlated with infant physiological indices and health outcomes, may be operationalized at the bedside to measure procedural distress, and help to guide the ideal timing to perform procedures and minimize their negative consequence.

A multidimensional approach to pain assessment in critically ill infants during a painful procedure

OBJECTIVES

Inferring the pain level of a critically ill infant is complex. The ability to accurately extract the appropriate pain cues from observations is often jeopardized when heavy sedation and muscular blocking agents are administered. Near-infrared spectroscopy is a noninvasive method that may provide the bridge between behavioral observational indicators and cortical pain processing. We aimed to describe regional cerebral and systemic hemodynamic changes, as well as behavioral reactions in critically ill infants with congenital heart defects during chest-drain removal after cardiac surgery.

METHODS

Our sample included 20 critically ill infants with congenital heart defects, less than 12 months of age, admitted to the cardiac intensive care unit after surgery.

RESULTS

Cerebral deoxygenated hemoglobin concentrations significantly differed across the epochs (i.e., baseline, tactile stimulus, noxious stimulus) (P=0.01). Physiological systemic responses and Face Leg Activity Cry Consolability (FLACC) pain scores differed significantly across the events (P<0.01). The 3 outcome measures were not found to be associated with each other. Mean FLACC pain scores during the painful procedure was 7/10 despite administration of morphine. Midazolam administration accounted for 36% of the variance in pain scores.

DISCUSSION

We demonstrated with a multidimensional pain assessment approach that significant cerebral, physiological, and behavioral activity was present in response to a noxious procedure in critically ill infants despite the administration of analgesic treatment. Considering that the sedating agent significantly dampened pain behaviors, assessment of cerebral hemodynamic in the context of pain seems to be an important addition.

Role of sucrose in reducing painful response to orogastric tube insertion in preterm neonates

OBJECTIVES

To study whether orogastric tube (OGT) insertion elicits a painful response in preterm neonates, and the role of oral sucrose in reducing this pain.

METHODS

This double blinded, randomized control trial was conducted in the neonatal intensive care units of Kalawati Saran Children's Hospital. Clinically stable preterms within the first 7 postnatal days, who had not received painful stimulus 30 min prior to intervention, and who required routine OGT insertion were included. Lingual 24 % sucrose or distilled water (1 ml) was administered 2 min before OGT insertion. The primary outcome was painful response assessed by Premature Infant Pain Profile scale (PIPP), while the secondary outcomes were heart rate and SpO2 changes. The trial is registered with ClinicalTrials.gov (

REGISTRATION NUMBER

NCT 00949104) RESULTS: Sixty preterms were randomized in each group. Final analysis was carried out on 52 subjects in the placebo group and 53 in the sucrose group. The mean intra-procedure PIPP scores were significantly higher than the mean pre-procedure PIPP scores, in the gestational age groups of more than 34 wk, and 32 wk to 33 wk, 6 d, in both the placebo (7.25 vs. 3, and 8.14 vs. 3.14, respectively) and sucrose arm (8.06 vs. 3.21, and 7.18 vs. 4.18, respectively). The mean PIPP scores assessed at 30 s post procedure in the sucrose group were significantly lower than the placebo group (4.32 vs. 5.6, p = 0.014). No significant adverse events were seen.

CONCLUSIONS

OGT insertion causes pain in preterms and single dose lingual 24 % sucrose may alleviate this pain.

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

BACKGROUND

Evidence indicates that medical and demographic contextual factors (cFs) impact pain responses in preterm neonates, but the existing evidence is very heterogeneous.

AIM

To explore the effect of cFs on pain responses to heel-stick procedures of preterm infants.

METHODS

This study was a secondary analysis of data collected during a randomized controlled trial examining pain response to non-pharmacological interventions across repeated heel sticks. Five heel sticks across the first 14 days of life were videotaped. Pain response was rated with the Bernese Pain Scale for Neonates (BPSN) by four raters blinded to the heel-stick phases (baseline, heel stick, recovery). Demographic and medical cFs were extracted from medical charts. Mixed single and multiple regression analyses were performed controlling for the intervention group, site and heel-stick phase.

RESULTS

Apgar scores at 1 min were negatively associated with behavioural (p = 0.002) BPSN scores, while Apgar scores at 5 min after birth were positively associated with behavioural (p = 0.006) scores. Accumulated number of painful procedures (p = 0.002) and gender (p = 0.02) were positively associated with physiological scores while continuous positive airway pressure CPAP (p = 0.009) and mechanical ventilation (p = 0.005) were negatively associated.

CONCLUSION

Higher exposure to painful procedures, male infants and having CPAP or mechanical ventilation were cFs associated with physiological response. The only variables significantly associated with behavioural BPSN scores were Apgar scores but these relationships were inconsistent.

Sugaring the pill: ethics and uncertainties in the use of sucrose for newborn infants

Sucrose is widely used for the management of procedural pain in newborn infants, including capillary blood sampling, venepuncture, and vascular cannulation. Multiple randomized controlled trials have demonstrated that sweet-tasting solutions reduce behavioral responses to acute painful stimuli. It has been claimed that sucrose should be a standard of care in neonatal units and that further placebo-controlled trials of sucrose are unnecessary and unethical. However, recently published data cast doubt on the analgesic properties of sucrose. We review this new evidence and analyze the philosophical and ethical questions that it raises, including the "problem of other minds." Sugar may be better understood not as an analgesic, removing or relieving pain, but as a compensating pleasure. There is a need for further research on the mechanism of sucrose's effect on pain behavior and on the long-term effects of sucrose treatment. Such trials will require comparison with placebo or with other interventions. Given uncertainty about the benefit of sucrose, it may be wise to use alternative analgesics or nonpharmacological interventions where these are available and appropriate. Sucrose may not be the answer to procedural pain in newborns.

Is fetal pain a real evidence?

Due to the progress in fetal surgery, it is important to acquire data about fetal pain.

MATERIAL AND METHODS

We performed a Medline research from 1995, matching the following key words: "pain" and "fetus", with the following: "subplate", "thalamocortical", "myelination", "analgesia", "anesthesia", "brain", "behavioral states", "substance p". We focused on: (a) fetal development of nociceptive pathways; (b) fetal electrophysiological, endocrinological and behavioral reactions to stimuli and pain.

RESULTS

We retrieved 217 papers of which 157 were highly informative; some reported similar data or were only case-reports, and were not quoted. Most endocrinological, behavioral and electrophysiological studies of fetal pain are performed in the third trimester, and they seem to agree that the fetus in the 3rd trimester can experience pain. But the presence of fetal pain in the 2nd trimester is less evident. In favor of a 2nd trimester perception of pain is the early development of spino-thalamic pathways (approximately from the 20th week), and the connections of the thalamus with the subplate (approximately from the 23rd week). Against this possibility, some authors report the immaturity of the cortex with the consequent lack of awareness, and the almost continuous state of sleep of the fetus.

CONCLUSIONS

Most studies disclose the possibility of fetal pain in the third trimester of gestation. This evidence becomes weaker before this date, though we cannot exclude its increasing presence since the beginning of the second half of the gestation.

Maternal touch and talk for invasive procedures in infants and toddlers in the pediatric intensive care unit

The aim of this single-blind, randomized, crossover trial was to test the effect of Touch & Talk (T&T) for infants and toddlers less than 36 months of age (N = 65) in the pediatric intensive care unit on their physiological stability and recovery to an invasive procedure. In the T&T condition, mothers touched, sang, or told stories or rhymes to their child during an invasive procedure. In the control condition, the mothers did not have contact with their child. Physiological measures included heart rate, heart rate variability, and oxygen saturation range during the procedure and change from baseline. Time from the end of the procedure until the heart rate returned to baseline levels gave the recovery time. Analysis was conducted using repeated-measures analysis of covariance. There were no significant differences on any of the physiological parameters by condition during the procedure. However, when controlling for severity of illness, recovery was faster with mothers.

Assessing pain in preterm infants in the neonatal intensive care unit: moving to a 'brain-oriented' approach

Preterm infants in the neonatal intensive care unit undergo repeated exposure to procedural and ongoing pain. Early and long-term changes in pain processing, stress-response systems and development may result from cumulative early pain exposure. So that appropriate treatment can be given, accurate assessment of pain is vital, but is also complex because these infants' responses may differ from those of full-term infants. A variety of uni- and multidimensional assessment tools are available; however, many have incomplete psychometric testing and may not incorporate developmentally important cues. Near-infrared spectroscopy and/or EEG techniques that measure neonatal pain responses at a cortical level offer new opportunities to validate neonatal pain assessment tools.

Contextual factors influencing pain response to heelstick procedures in preterm infants: what do we know? A systematic review

Major efforts to develop objective measurement tools for neonatal pain assessment have been made. However, the challenge of measuring pain in neonates remains suggesting that contextual factors (cFs) might alter their responses to pain. Although the role of cFs is increasingly discussed as crucial for pain assessment, they are not well described in the literature and are rarely considered in the clinical setting despite their importance.

AIM

To systematically examine studies investigating the impact of cFs on pain response in preterm infants.

METHOD

A literature search was undertaken for the period from 1990 to 2009. Studies reporting the relation between one or more cFs and pain response in preterm infants during a heelstick procedure were considered for inclusion.

RESULTS

Twenty-three studies satisfied inclusion criteria. The studies varied relative to their design, sample, analysis procedures, and variables examined. Six categories of cFs emerged: age, pain exposure, health status, therapeutic interventions, behavioral status, and demographic factors. The examined cFs varied in the strength of their association with pain response, although none were invariably related, as evidenced by contradictory findings. In some cases the inconsistencies appeared attributable to methodological limitations in studies. Behavioral and physiological pain responses were not always in agreement as would be expected.

CONCLUSION

This review supports the influence of some cFs on pain response. However, the results remain inconclusive which may be, in part, related to the heterogeneity of the studies. Contextual factors need further investigation for a better understanding of the magnitude of their effect on pain response.

Pain in neonates is different

Pain processing and management in neonates, especially preterm neonates, differs from older populations. In this review, a brief background on pain processing in neonatal life, pain exposure in Neonatal Intensive Care Units (NICU), the consequences of untreated pain, and the difficulties in treating procedural pain pharmacologically will be presented. A more detailed review of non-pharmacological interventions for procedural pain in neonates will include sensory stimulation approaches, oral sweet solutions, and maternal interventions. Some possible mechanisms for the effectiveness of non-pharmacological interventions are offered. Finally, avenues of research into similar interventions as adjuvant therapies or drug-sparing effects in older populations are suggested.

Validity and reliability of the N-PASS assessment tool with acute pain

OBJECTIVE

To establish evidence of clinical validity and reliability of the Neonatal Pain, Agitation, and Sedation Scale (N-PASS) in neonates with acute heelstick pain.

STUDY DESIGN

Prospective psychometric evaluation, randomized crossover design. Two nurses administered the N-PASS simultaneously and independently during an actual and sham heelstick done in randomized order. One nurse also administered the Premature Infant Pain Profile (PIPP) concurrently with the N-PASS. Heelsticks were videotaped for repeat analysis.

RESULT

Construct (discriminate) validity was established through the Wilcoxon Signed-ranks test, comparing the distribution of the heelstick and sham N-PASS scores. The mean pain scores were 3.93 (2.30) and 0.81 (1.21) for the heelstick and sham procedures, respectively (Z=-6.429, P<0.0001). Convergent validity was demonstrated by correlation with the PIPP scores (Spearman rank correlation coefficient of 0.75 and 0.72 for raters 1 and 2, respectively). Inter-rater reliability was high, measured by intra-class coefficients; the ICC estimates (95% CI) of the pain scale were 0.86 (0.78, 0.92) and 0.93 (0.88, 0.96) for a single rating and average of two independent ratings, respectively (P<0.0001). Internal consistency, measured by Cronbach's alpha, was evident (0.84 to 0.89). Test-retest reliability was demonstrated by repeat scoring of videotaped heelsticks, measured by Spearman's rho correlation (0.874, P<0.0001).

CONCLUSION

This research provides beginning evidence that the N-PASS is a valid and reliable tool for assessing acute heelstick pain in infants 0 to 30 days of age, 23 to 40 weeks gestation.

Latency to facial expression change following noxious stimulation in infants is dependent on postmenstrual age

Change in facial expression over a fixed time after a noxious stimulus is the key measure used to calculate pain scores in preterm and newborn infants. We hypothesised that the latency of facial motor responses would be longer in the youngest premature infants and that behavioural scoring methods of pain may need to take this into account. One hundred and seventy-two clinically required heel lances were performed in 95 infants from 25 to 44 weeks postmenstrual age (PMA). Sixty-four percentage of the heel lances evoked a change in facial expression. Change in facial expression was observed in infants across the whole age range from 25 weeks PMA and the latency to the facial expression response ranged from 1 to 17s. Latency to facial expression change was dependent on the infants' PMA at the time of the heel lance. Infants below 32 weeks PMA had a significantly longer latency to change in facial expression than older infants (54% increase in infants below 32 weeks; p < 0.001). Sleep state and presence of brain damage (IVH grades 1-4) did not significantly increase the latency (p > 0.05 for each variable). Intravenous morphine at the time of the heel lance significantly increased the latency to facial expression response (p < 0.001) but the analysis shows that latency is highly dependent on PMA independent of morphine administration. These findings highlight developmental changes underlying infant behaviour that are critically important if pain scores are to be correctly interpreted.

Caregiving behavior and interactions of prenatally depressed mothers (antidepressant-treated and non-antidepressant-treated) during newborn acute pain

This exploratory study aimed to examine time-based measures of the behaviors and interactions of prenatally depressed serotonin reuptake inhibitors (SRI)-medicated mothers to their infant's pain (n = 10) by comparing them with similar measures obtained from prenatally depressed nonmedicated mothers and their infants (n = 10), and nondepressed mothers and their infants (n = 10). During the second trimester of their pregnancy, the 30 study mothers were assessed for depression and anxiety, with no further measures of maternal mood taken. Maternal and infant interactions were continuously videorecorded while the infant underwent a scheduled heel lance for routine blood screening that occurred when study infants were between the ages of 24 and 60 hr. Maternal behavior and infant cry, for all 30 cases, were coded second-by-second for the full duration of each infant's heel lance using a reliable coding system and analyzed using odds ratio and regression analyses. Infants exposed to prenatal SRIs and depressed maternal mood were more likely to have lower Apgar scores and to exhibit weak and absent cry. Even when duration of the heel lance was controlled for, women with depression during the second trimester were more likely to exhibit depressed behavior at 2 days' postpartum despite sustained SRI antidepressant treatment. Both groups of prenatally depressed mothers were more likely to exhibit diminished response to their infants' pain cue although nonmedicated mothers' expressions of depressed behavior were more similar to healthy controls. Comprehensive understanding is essential to optimize the clinical care of mothers and their infants in this complex setting. This study contributes preliminary new findings that warrant prospective and longitudinal studies to clarify further the impacts of prenatal SRI and maternal mental mood (e.g., chronic depression and anxiety) effects on the mother-infant interaction and infant pain and stress reactivity.

The effect of Kangaroo Care on behavioral responses to pain of an intramuscular injection in neonates

PURPOSE

This study aims to assess the efficacy of Kangaroo Care (KC) on behavioral responses of term neonates to the pain of an intramuscular injection.

DESIGN AND METHODS

One hundred healthy term neonates were enrolled and randomly assigned to intervention and control groups. In the intervention group, the neonate was held in KC for 10 min before the injection and remained in KC for the duration of the procedure. The primary outcome measure was the cumulative Neonatal Infant Pain Scale (NIPS) score immediately after injection.

RESULTS

The cumulative NIPS score immediately after injection in the intervention group was significantly lower (p<.001) than in the control group.

PRACTICE IMPLICATIONS

KC given before injection seems to effectively decrease pain and should be considered for minor invasive procedures in neonates.