Pain and distress caused by endotracheal suctioning in neonates is better quantified by behavioural than physiological items: a comparison based on item response theory modelling

Non-pharmacological interventions for the prevention of pain during endotracheal suctioning in ventilated neonates

BACKGROUND

Pain, when treated inadequately, puts preterm infants at a greater risk of developing clinical and behavioural sequelae because of their immature pain system. Preterm infants in need of intensive care are repeatedly and persistently exposed to noxious stimuli, and this happens during a critical window of their brain development with peak rates of brain growth, exuberant synaptogenesis and the developmental regulation of specific receptor populations. Nearly two-thirds of infants born at less than 29 weeks' gestation require mechanical ventilation for some duration during the newborn period. These neonates are endotracheally intubated and require repeated endotracheal suctioning. Endotracheal suctioning is identified as one of the most frequent and most painful procedures in premature infants, causing moderate to severe pain. Even with improved nursing performance and standard procedures based on neonatal needs, endotracheal suctioning remains associated with mild pain.

OBJECTIVES

To evaluate the benefits and harms of non-pharmacological interventions for the prevention of pain during endotracheal suctioning in mechanically ventilated neonates. Non-pharmacological interventions were compared to no intervention, standard care or another non-pharmacological intervention.

SEARCH METHODS

We conducted searches in June 2023 in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, Embase, CINAHL and three trial registries. We searched the reference lists of related systematic reviews, and of studies selected for inclusion.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), quasi-RCTs and cluster-RCTs that included term and preterm neonates who were mechanically ventilated via endotracheal tube or via tracheostomy tube and required endotracheal suctioning performed by doctors, nurses, physiotherapists or other healthcare professionals.

DATA COLLECTION AND ANALYSIS

Our main outcome measures were validated composite pain scores (including a combination of behavioural, physiological and contextual indicators). Secondary outcomes included separate physiological and behavioural pain indicators. We used standard methodological procedures expected by Cochrane. For continuous outcome measures, we used a fixed-effect model and reported mean differences (MDs) with 95% confidence intervals (CIs). For categorical outcomes, we reported the typical risk ratio (RR) and risk difference (RD) and 95% CIs. We assessed risk of bias using the Cochrane RoB 1 tool, and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included eight RCTs (nine reports), which enroled 386 infants, in our review. Five of the eight studies were included in a meta-analysis. All studies enrolled preterm neonates. Facilitated tucking versus standard care (four studies) Facilitated tucking probably reduces Premature Infant Pain Profile (PIPP) score during endotracheal suctioning (MD -2.76, 95% CI 3.57 to 1.96; I² = 82%; 4 studies, 148 infants; moderate-certainty evidence). Facilitated tucking probably has little or no effect during endotracheal suctioning on: heart rate (MD -3.06 beats per minute (bpm), 95% CI -9.33 to 3.21; I² = 0%; 2 studies, 80 infants; low-certainty evidence); oxygen saturation (MD 0.87, 95% CI -1.33 to 3.08; I² = 0%; 2 studies, 80 infants; low-certainty evidence); or stress and defensive behaviours (SDB) (MD -1.20, 95% CI -3.47 to 1.07; 1 study, 20 infants; low-certainty evidence). Facilitated tucking may result in a slight increase in self-regulatory behaviours (SRB) during endotracheal suctioning (MD 0.90, 95% CI 0.20 to 1.60; 1 study, 20 infants; low-certainty evidence). No studies reported intraventricular haemorrhage (IVH). Familiar odour versus standard care (one study) Familiar odour during endotracheal suctioning probably has little or no effect on: PIPP score (MD -0.30, 95% CI -2.15 to 1.55; 1 study, 40 infants; low-certainty evidence); heart rate (MD -6.30 bpm, 95% CI -16.04 to 3.44; 1 study, 40 infants; low-certainty evidence); or oxygen saturation during endotracheal suctioning (MD -0.80, 95% CI -4.82 to 3.22; 1 study, 40 infants; low-certainty evidence). No studies reported SRB, SDB or IVH. White noise (one study) White noise during endotracheal suctioning probably has little or no effect on PIPP (MD -0.65, 95% CI -2.51 to 1.21; 1 study, 40 infants; low-certainty evidence); heart rate (MD -1.85 bpm, 95% CI -11.46 to 7.76; 1 study, 40 infants; low-certainty evidence); or oxygen saturation (MD 2.25, 95% CI -2.03 to 6.53; 1 study, 40 infants; low-certainty evidence). No studies reported SRB, SDB or IVH.

AUTHORS' CONCLUSIONS

Facilitated tucking / four-handed care / gentle human touch probably reduces PIPP score. The evidence of a single study suggests that facilitated tucking / four-handed care / gentle human touch slightly increases self-regulatory and approach behaviours during endotracheal suctioning. Based on a single study, familiar odour and white noise have little or no effect on any of the outcomes compared to no intervention. The use of expressed breast milk or oral sucrose suggests that there is no discernible advantage of one method over the other for reducing pain during endotracheal suctioning. None of the studies reported on any of the prespecified secondary outcomes of adverse events.

Advances in pharmacokinetic-pharmacodynamic modelling for pediatric drug development: extrapolations and exposure-response analyses

INTRODUCTION

Pharmacokinetic (PK)-Pharmacodynamic (PD) and exposure-response (E-R) modeling are critical parts of pediatric drug development. By integrating available knowledge and supportive data to support the design of future studies and pediatric dose selection, these techniques increase the efficiency of pediatric drug development and lowers the risk of exposing pediatric study participants to suboptimal or unsafe dose regimens.

AREAS COVERED

The role of PK, PK-PD and E-R modeling within pediatric drug development and pediatric dose selection is discussed. These models allow investigation of the impact of age and bodyweight on PK and PD in children, despite the often sparse data on the pediatric population. Also discussed is how E-R analyses strengthen the evidence basis to support (full or partial) extrapolation of drug efficacy from adults to children, and between different pediatric age groups.

EXPERT OPINION

Accelerated pediatric drug development and optimized pediatric dosing guidelines are expected from three future developments: (1) Increased focus on E-R modeling of currently approved drugs in children resulting in (novel) E-R modeling techniques and best practices, (2) increased use of real-world data for E-R (3) increased implementation of available population PK and E-R information in pediatric drug dosing guidelines.

Effects of white noise on procedural pain-related cortical response and pain score in neonates: A randomized controlled trial

Objectives

To evaluate the effects of white noise on pain-related cortical response, pain score, and behavioral and physiological parameters in neonates with procedural pain.

Methods

A double-blind, randomized controlled trial was conducted. Sixty-six neonates from the Neonatal Intensive Care Unit in a university-affiliated general hospital were randomly assigned to listen to white noise at 50 dB (experimental group) or 0 dB (control group) 2 min before radial artery blood sampling and continued until 5 min after needle withdrawal. Pain-related cortical response was measured by regional cerebral oxygen saturation (rScO₂) monitored with near-infrared spectroscopy, and facial expressions and physiological parameters were recorded by two video cameras. Two assessors scored the Premature Infant Pain Profile-Revised (PIPP-R) independently when viewing the videos. Primary outcomes were pain score and rScO₂ during arterial puncture and 5 min after needle withdrawal. Secondary outcomes were pulse oximetric oxygen saturation (SpO₂) and heart rate (HR) during arterial puncture, and duration of painful expressions. The study was registered at the Chinese Clinical Trial Registry (ChiCTR2200055571).

Results

Sixty neonates (experimental group, n = 29; control group, n = 31) were included in the final analysis. The maximum PIPP-R score in the experimental and control groups was 12.00 (9.50, 13.00), 12.50 (10.50, 13.75), respectively (median difference −0.5, 95% CI −2.0 to 0.5), and minimum rScO₂ was (61.22 ± 3.07)%, (61.32 ± 2.79)%, respectively (mean difference −0.325, 95% CI −1.382 to 0.732), without significant differences. During arterial puncture, the mean rScO₂, HR, and SpO₂ did not differ between groups. After needle withdrawal, the trends for rScO₂, PIPP-R score, and facial expression returning to baseline were different between the two groups without statistical significance.

Conclusion

The white noise intervention did not show beneficial effects on pain-related cortical response as well as pain score, behavioral and physiological parameters in neonates with procedural pain.

The Effect of Endotracheal Suctioning Using the Four-handed Care on Physiological Criteria and Behavioral Responses of the Preterm Infants: Randomized Crossover Clinical Trial

Background: Endotracheal suctioning, despite its necessity, is one of the procedures that can cause pain and stress for infants admitted to neonatal intensive care units. Pain and stress manifest with physiological and behavioral responses in infants. Purpose: This study is a cross-sectional clinical trial that aimed to investigate the effect of endotracheal suctioning using four-handed care on the physiological criteria and behavioral responses of preterm infants. Methods:In this study, 40 infants were randomly divided into two groups of 20, one group was first suctioned by the routine method (two hands) and then with the four-handed method. The other group was first suctioned by the four-handed method and then with the routine one. The ALPS NEO was used to evaluate behavioral criteria. One camera recorded facial expressions and body movements, and physiological data were recorded from the monitor simultaneously. Results:Four-handed suctioning method can prevent an increase in heart rate during and two minutes after suctioning but it did not affect behavioral responses and oxygen saturation of the preterm infants admitted to NICUs. Since one of the symptoms of pain and stress in infants is the change of vital signs, especially the heart rate, stable heart rate during painful procedures can be an indication of the effectiveness of the four-hand method in invasive procedures such as suctioning. Implications for Practice: We recommend four-handed method for suctioning of endotracheal tube. Implications for Research: Evaluate the effect of four-handed care by mother on physiological criteria and behavioral responses of the preterm infants.

2022 Society of Critical Care Medicine Clinical Practice Guidelines on Prevention and Management of Pain, Agitation, Neuromuscular Blockade, and Delirium in Critically Ill Pediatric Patients With Consideration of the ICU Environment and Early Mobility

RATIONALE

A guideline that both evaluates current practice and provides recommendations to address sedation, pain, and delirium management with regard for neuromuscular blockade and withdrawal is not currently available.

OBJECTIVE

To develop comprehensive clinical practice guidelines for critically ill infants and children, with specific attention to seven domains of care including pain, sedation/agitation, iatrogenic withdrawal, neuromuscular blockade, delirium, PICU environment, and early mobility.

DESIGN

The Society of Critical Care Medicine Pediatric Pain, Agitation, Neuromuscular Blockade, and Delirium in critically ill pediatric patients with consideration of the PICU Environment and Early Mobility Guideline Taskforce was comprised of 29 national experts who collaborated from 2009 to 2021 via teleconference and/or e-mail at least monthly for planning, literature review, and guideline development, revision, and approval. The full taskforce gathered annually in-person during the Society of Critical Care Medicine Congress for progress reports and further strategizing with the final face-to-face meeting occurring in February 2020. Throughout this process, the Society of Critical Care Medicine standard operating procedures Manual for Guidelines development was adhered to.

METHODS

Taskforce content experts separated into subgroups addressing pain/analgesia, sedation, tolerance/iatrogenic withdrawal, neuromuscular blockade, delirium, PICU environment (family presence and sleep hygiene), and early mobility. Subgroups created descriptive and actionable Population, Intervention, Comparison, and Outcome questions. An experienced medical information specialist developed search strategies to identify relevant literature between January 1990 and January 2020. Subgroups reviewed literature, determined quality of evidence, and formulated recommendations classified as "strong" with "we recommend" or "conditional" with "we suggest." Good practice statements were used when indirect evidence supported benefit with no or minimal risk. Evidence gaps were noted. Initial recommendations were reviewed by each subgroup and revised as deemed necessary prior to being disseminated for voting by the full taskforce. Individuals who had an overt or potential conflict of interest abstained from relevant votes. Expert opinion alone was not used in substitution for a lack of evidence.

RESULTS

The Pediatric Pain, Agitation, Neuromuscular Blockade, and Delirium in critically ill pediatric patients with consideration of the PICU Environment and Early Mobility taskforce issued 44 recommendations (14 strong and 30 conditional) and five good practice statements.

CONCLUSIONS

The current guidelines represent a comprehensive list of practical clinical recommendations for the assessment, prevention, and management of key aspects for the comprehensive critical care of infants and children. Main areas of focus included 1) need for the routine monitoring of pain, agitation, withdrawal, and delirium using validated tools, 2) enhanced use of protocolized sedation and analgesia, and 3) recognition of the importance of nonpharmacologic interventions for enhancing patient comfort and comprehensive care provision.

Neonatal pain assessment: Do we have the right tools?

BACKGROUND

The assessment and management of neonatal pain is crucial for the development and wellbeing of vulnerable infants. Specifically, neonatal pain is associated with adverse health outcomes but is often under-identified and therefore under-treated. Neonatal stress may be misinterpreted as pain and may therefore be treated inappropriately. The assessment of neonatal pain is complicated by the non-verbal status of patients, age-dependent variation in pain responses, limited education on identifying pain in premature infants, and the clinical utility of existing tools.

OBJECTIVE

We review research surrounding neonatal pain assessment scales currently in use to assess neonatal pain in the neonatal intensive care unit.

METHODS

We performed a systematic review of original research using PRISMA guidelines for literature published between 2016 and 2021 using the key words "neonatal pain assessment" in the databases Web of Science, PubMed, and CINAHL. Fifteen articles remained after review, duplicate, irrelevant, or low-quality articles were eliminated.

RESULTS

We found research evaluating 13 neonatal pain scales. Important measurement categories include behavioral parameters, physiological parameters, continuous pain, acute pain, chronic pain, and the ability to distinguish between pain and stress. Provider education, inter-rater reliability and ease of use are important factors that contribute to an assessment tool's success. Each scale studied had strengths and limitations that aided or hindered its use for measuring neonatal pain in the neonatal intensive care unit, but no scale excelled in all areas identified as important for reliably identifying and measuring pain in this vulnerable population.

CONCLUSION

A more comprehensive neonatal pain assessment tool and more provider education on differences in pain signals in premature neonates may be needed to increase the clinical utility of pain scales that address the different aspects of neonatal pain.

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.

Exploration and Validation of Behavioral Pain Measures and Physiological Pain Measures Factor Structure Extracted From the Pain Assessment Tool Item Scores for Infants Admitted to Neonatal Intensive Care

OBJECTIVE

The objective of the study was to explore and then validate the factor structure of the Pain Assessment Tool (PAT).

MATERIALS AND METHODS

A retrospective medical record review was performed of all infants who were admitted to a neonatal intensive care unit between 2008 and 2018 and had 1 PAT assessment (n=2111). Scores on items of the PAT were collected. Infants were randomized to either the principal component analysis (n=1100) to explore the factor structure or confirmatory factor analysis (n=1011).

RESULTS

Infants in the 2 samples were demographically comparable. A 2-factor model, consisting of factors Behavioral and Physiological Pain Measures, was extracted, explaining 39.8% of the total variance. There was a low interfactor correlation (r=0.12), and both Behavioral (r=0.59) and Physiological Pain (r=0.37) Measures factor scores were correlated with nurses' perception of pain scores. When the frequencies in the gestational age at birth categories were compared between upper and lower quartile score infants, there was more with pain at preterm than at term (χ2(3)=44.9, P<0.001) for the Physiological Pain Measures factor, whereas Behavioral Pain Measures frequency was higher at term than at preterm (χ2(3)=8.1, P<0.043). A similar pattern was observed for postmenstrual age at assessment categories: Behavioral Pain Measures (χ2(3)=41.8, P<0.001) Physiological Pain Measures (χ2(3)=46.1, P<0.001). The 2-factor correlated model performed better at explaining the observed variances: (χ2(13)=41.6, P<0.001) compared with rival models.

DISCUSSION

The PAT assesses both Behavioral Pain and Physiological Pain Measures, and these dimensions need to be considered separately when assessing pain in infants in the neonatal intensive care unit. Behavioral item scores may be insufficient for detecting pain in premature infants if used alone.

Pharmacotherapy of neonatal opioid withdrawal syndrome: a review of pharmacokinetics and pharmacodynamics

INTRODUCTION

Neonatal opioid withdrawal syndrome (NOWS) often arises in infants born to mothers who used opioids during pregnancy. Morphine, methadone, and buprenorphine are the most common first-line treatments, whereas clonidine and phenobarbital are generally reserved for adjunctive therapy. These drugs exhibit substantial pharmacokinetic (PK) and pharmacodynamic (PD) variability. Current pharmacological treatments for NOWS are based on institutional protocols and largely rely on empirical treatment of patient symptoms.

AREAS COVERED

This article reviews the PK/PD of NOWS pharmacotherapies with a focus on the implication of physiological development and maturation. Body size-standardized clearance is consistently low in neonates, except for methadone. This can be ascribed to underdeveloped metabolic and elimination pathways. The effects of pharmacogenetics have been clarified especially for morphine. The PK/PD relationship of medications used in the treatment of NOWS is generally understudied.

EXPERT OPINION

Providing an appropriate opioid dose in neonates is challenging. Advancements in quantitative pharmacology and PK/PD modeling approaches facilitate identification of key factors driving PK/PD variability and characterization of exposure-response relationships. PK/PD model-informed simulations have been widely employed to define age-appropriate pediatric dosing regimens. The model-informed approach holds promise to aid more rational use of medications in the treatment of NOWS.

Integrated Item Response Theory Modeling of Multiple Patient-Reported Outcomes Assessing Lower Urinary Tract Symptoms Associated with Benign Prostatic Hyperplasia

In clinical trials within lower urinary tract symptoms due to benign prostatic hyperplasia (BPH-LUTS), the International Prostate Symptom Score (IPSS) is commonly the primary efficacy outcome while the Quality of Life (QoL) score and the BPH Impact Index (BII) are common secondary efficacy markers. The current study aimed to characterize BPH-LUTS progression using responses to the IPSS, the QoL, and the BII in an integrated item response theory (IRT) framework and assess the Fisher information of each scale. The power of this approach to detect a drug effect was compared with an IRT approach considering only IPSS responses. A unidimensional and a bidimensional pharmacometric IRT model, based on item-level IPSS responses in a clinical trial with 403 patients, were extended by incorporating patients’ QoL and summary BII scores over the 6-month trial period. In the developed unidimensional integrated model, the QoL score was found to be the most informative, representing 17% of the total Fisher information, while the combined information content of the seven IPSS items represented 70.6%. In the bidimensional model, “storage” and both storage and “voiding” disability drove QoL and summary BII responses, respectively. Sample size reduction of 16% to detect a drug effect at 80% power was obtained with the unidimensional integrated IRT model compared with its counterpart IPSS IRT model. This study shows that utilizing the information content across the IPSS, QoL, and BII scales in an integrated IRT framework results in a modest but meaningful increase in power to detect a drug effect.

Temporal assessment of neonatal pain after airway aspiration

OBJECTIVE

To temporally assess a painful stimulus in premature infants using 3 neonatal pain scales.

METHODS

A total of 83 premature infants were observed during airway aspiration by 3 evaluators (E1, E2 and E3) using 3 pain assessment scales (Neonatal Facial Coding System - NFCS; Neonatal Infant Pain Scale - NIPS; and Premature Infant Pain Profile - PIPP) at 5 time points: T1 (before airway aspiration), T2 (during airway aspiration), T3 (1 minute after airway aspiration), T4 (3 minutes after airway aspiration), and T5 (5 minutes after airway aspiration). Light's Kappa (agreement among examiners and among scales at each time point) and the McNemar test (comparison among time points) were used considering p < 0.05.

RESULTS

There was a significant difference between the 3 examiners for T1 and T2 using the 3 scales. In T3, pain was observed in 22.9%/E1, 28.9%/E2, and 24.1%/E3 according to the NFCS; 22.9%/E1, 21.7%/E2, and 16.9%/E3 according to the NIPS; and 49.4%/E1, 53.9%/E2, and 47%/E3 according to the PIPP. There was a difference between T1 and T3 using the 3 scales, except for 2 examiners for the PIPP (E2: p = 0.15/E3: p = 0.17). Comparing T4 and T5 to T1, there was no difference in the 3 scales.

CONCLUSION

Premature infants required at least 3 minutes to return to their initial state of rest (no pain).

Individualised developmental care for babies and parents in the NICU: Evidence-based best practice guideline recommendations

Advances in neonatal care have improved survival of premature and critically ill infants; and while rates of some long-term neurodevelopmental problems in survivors have improved, such as cerebral palsy, there are others such as learning and behavioural difficulties that have not. The goal of improving long term neurodevelopmental morbidity has led to an increased focus on improving developmental care not only in neonatal long term follow- up clinics but within the NICU itself to capture the period of earliest brain neuroplasticity. The application of a systematic approach to improve practice is considered the most effective strategy for implementing neuroprotective developmentally supportive care. The content of this paper incorporates evidence-based systematic reviews to guide clinicians in the application of developmentally supportive interventions.

Supervised Multidimensional Item Response Theory Modeling of Pediatric Iatrogenic Withdrawal Symptoms

Item‐level data from composite scales can be analyzed with pharmacometric item response theory (IRT) models to improve the quantification of disease severity compared with the use of total composite scores. However, regular IRT models assume unidimensionality, which is violated in the scale measuring iatrogenic withdrawal in children because some items are also affected by pain, undersedation, or delirium. Here, we compare regular IRT modelling of pediatric iatrogenic withdrawal symptom data with two new analysis approaches in which the latent variable is guided towards the condition of interest using numerical withdrawal severity scored by nurses as a “supervising variable:” supervised IRT (sIRT) and supervised multi‐dimensional (smIRT) modelling. In this example, in which the items scores are affected by multiple conditions, regular IRT modeling is worse to quantify disease severity than the total composite score, whereas improved performance compared with the composite score is observed for the sIRT and smIRT models.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Novel Method for Analysing Frequent Observations from Questionnaires in Order to Model Patient-Reported Outcomes: Application to EXACT® Daily Diary Data from COPD Patients

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease with approximately 174 million cases worldwide. Electronic questionnaires are increasingly used for collecting patient-reported-outcome (PRO) data about disease symptoms. Our aim was to leverage PRO data, collected to record COPD disease symptoms, in a general modelling framework to enable interpretation of PRO observations in relation to disease progression and potential to predict exacerbations. The data were collected daily over a year, in a prospective, observational study. The e-questionnaire, the EXAcerbations of COPD Tool (EXACT®) included 14 items (i.e. questions) with 4 or 5 ordered categorical response options. An item response theory (IRT) model was used to relate the responses from each item to the underlying latent variable (which we refer to as disease severity), and on each item level, Markov models (MM) with 4 or 5 categories were applied to describe the dependence between consecutive observations. Minimal continuous time MMs were used and parameterised using ordinary differential equations. One hundred twenty-seven COPD patients were included (median age 67 years, 54% male, 39% current smokers), providing approximately 40,000 observations per EXACT® item. The final model suggested that, with time, patients more often reported the same scores as the previous day, i.e. the scores were more stable. The modelled COPD disease severity change over time varied markedly between subjects, but was small in the typical individual. This is the first IRT model with Markovian properties; our analysis proved them necessary for predicting symptom-defined exacerbations.

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.

How often do we perform painful and stressful procedures in the paediatric intensive care unit? A prospective observational study

BACKGROUND

Adequate analgesia and sedation is crucial in critical care. There is little knowledge on the extent of painful and stressful procedures on children admitted to a paediatric intensive care unit (PICU) and its analgesic and/or sedative management.

OBJECTIVE

The primary objective was to determine the number of painful and stressful procedures per patient per day in our PICU patients, including the numbers of attempts. A secondary objective was to map PICU nurses' perceptions of the painfulness of the included procedures.

METHODS

A prospective, single-centre observational cohort study in a tertiary PICU. All patients admitted to the PICU over a 3-month period were eligible. Readmissions, polysomnography patients, and patients without any data have been excluded. The number of painful and stressful procedures was collected daily, and use of analgesics and sedatives was assessed and recorded daily. Twenty-five randomly assigned nurses rated the painfulness of procedures based on their personal experience using a numeric rating scale from 0 to 10.

RESULTS

In a 3-month period, a total of 229 patients were included, accounting for 855 patient days. The median number of painful and stressful procedures per patient per day was 11 (interquartile range=5-23). Endotracheal suctioning was the most frequent procedure (45%), followed by oral and nasal suctioning. Arterial and lumbar puncture, peripheral IV cannula insertion, and venipuncture were scored as most painful ranging from 3 to 10. Procedural analgesia or sedation was often not used during these most painful procedures.

CONCLUSIONS

Mechanically ventilated patients undergo more than twice as many painful procedures than non-ventilated patients, as endotracheal suctioning accounts for almost half of all. Nurses regarded skin-breaking procedures most painful; however, these were rarely treated by procedural analgosedation and only covered in the minority of cases by adequate background analgosedation.

Pharmacokinetic considerations for pediatric patients receiving analgesia in the intensive care unit; targeting postoperative, ECMO and hypothermia patients

INTRODUCTION

Adequate postoperative analgesia in pediatric patients in the intensive care unit (ICU) matters, since untreated pain is associated with negative outcomes. Compared to routine postoperative patients, children undergoing hypothermia (HT) or extracorporeal membrane oxygenation (ECMO), or recovering after cardiac surgery likely display non-maturational differences in pharmacokinetics (PK) and pharmacodynamics (PD). These differences warrant additional dosing recommendations to optimize pain treatment. Areas covered: Specific populations within the ICU will be discussed with respect to expected variations in PK and PD for various analgesics. We hereby move beyond maturational changes and focus on why PK/PD may be different in children undergoing HT, ECMO or cardiac surgery. We provide a stepwise manner to develop PK-based dosing regimens using population PK approaches in these populations. Expert opinion: A one-dose to size-fits-all for analgesia is suboptimal, but for several commonly used analgesics the impact of HT, ECMO or cardiac surgery on average PK parameters in children is not yet sufficiently known. Parameters considering both maturational and non-maturational covariates are important to develop population PK-based dosing advices as part of a strategy to optimize pain treatment.

Defining pain in newborns: need for a uniform taxonomy?

A framework for defining pain terms such as acute, persistent, prolonged or chronic pain to newborns was derived from the scientific literature on neonatal pain assessments, previous attempts to define chronic pain and the clinical and neurophysiological features of neonatal pain. This novel framework incorporates the temporal features, localising characteristics, and secondary effects of the pain experienced, as well as the behavioural and physiological response patterns of newborns.

CONCLUSION

Although not evidence-based, this framework provides an initial starting point for defining commonly used neonatal pain terms. It will require future revision/refinement based on the accumulating evidence for non-acute pain.

Non-maturational covariates for dynamic systems pharmacology models in neonates, infants, and children: Filling the gaps beyond developmental pharmacology

Pharmacokinetics and -dynamics show important changes throughout childhood. Studies on the different maturational processes that influence developmental pharmacology have been used to create population PK/PD models that can yield individualized pediatric drug dosages. These models were subsequently translated to semi-physiologically or physiology-based PK (PBPK) models that support predictions in pediatric patient cohorts and other special populations. Although these translational efforts are crucial, these models should be further improved towards individual patient predictions by including knowledge on non-maturational covariates. These efforts are needed to ultimately get to systems pharmacology models for children. These models take developmental changes relating to the pediatric dynamical system into account but also other aspects that may be of importance such as abnormal body composition, pharmacogenetics, critical illness and inflammatory status.

Evidence-based drug treatment for special patient populations through model-based approaches

The majority of marketed drugs remain understudied in some patient populations such as pregnant women, paediatrics, the obese, the critically-ill, and the elderly. As a consequence, currently used dosing regimens may not assure optimal efficacy or minimal toxicity in these patients. Given the vulnerability of some subpopulations and the challenges and costs of performing clinical studies in these populations, cutting-edge approaches are needed to effectively develop evidence-based and individualized drug dosing regimens. Five key issues are presented that are essential to support and expedite the development of drug dosing regimens in these populations using model-based approaches: 1) model development combined with proper validation procedures to extract as much valid information from available study data as possible, with limited burden to patients and costs; 2) integration of existing data and the use of prior pharmacological and physiological knowledge in study design and data analysis, to further develop knowledge and avoid unnecessary or unrealistic (large) studies in vulnerable populations; 3) clinical proof-of-principle in a prospective evaluation of a developed drug dosing regimen, to confirm that a newly proposed regimen indeed results in the desired outcomes in terms of drug concentrations, efficacy, and/or safety; 4) pharmacodynamics studies in addition to pharmacokinetics studies for drugs for which a difference in disease progression and/or in exposure-response relation is anticipated compared to the reference population; 5) additional efforts to implement developed dosing regimens in clinical practice once drug pharmacokinetics and pharmacodynamics have been characterized in special patient populations. The latter remains an important bottleneck, but this is essential to truly realize evidence-based and individualized drug dosing for special patient populations. As all tools required for this purpose are available, we have the moral and societal obligation to make safe and effective pharmacotherapy available for these patients too.

Morphine Pharmacodynamics in Mechanically Ventilated Preterm Neonates Undergoing Endotracheal Suctioning

To date, morphine pharmacokinetics (PKs) are well quantified in neonates, but results about its efficacy are ambiguous. This work presents an analysis of a previously published study on pain measurements in mechanically ventilated preterm neonates who received either morphine or placebo to improve comfort during invasive ventilation. The research question was whether morphine reduces the pain associated with endotracheal or nasal suctioning before, during, and after suctioning. Because these neonates cannot verbalize their pain levels, pain was assessed on the basis of several validated pain measurement instruments (i.e., COMFORT‐B, preterm infant pain profile [PIPP], Neonatal Infant Pain Scale (NIPS), and visual analogue scale (VAS)). The item response theory (IRT) was used to analyze the data in order for us to handle the data from multiple‐item pain scores. The analysis showed an intra‐individual relationship between morphine concentrations and pain reduction, as measured by COMFORT‐B and VAS. However, the small magnitude of the morphine effect was not considered clinically relevant for this intervention in preterm neonates.

Paracetamol and morphine for infant and neonatal pain; still a long way to go?

INTRODUCTION

Pharmacologic pain management in newborns and infants is often based on limited scientific data. To close the knowledge gap, drug-related research in this population is increasingly supported by the authorities, but remains very challenging. This review summarizes the challenges of analgesic studies in newborns and infants on morphine and paracetamol (acetaminophen). Areas covered: Aspects such as the definition and multimodal character of pain are reflected to newborn infants. Specific problems addressed include defining pharmacodynamic endpoints, performing clinical trials in this population and assessing developmental changes in both pharmacokinetics and pharmacodynamics. Expert commentary: Neonatal and infant pain management research faces two major challenges: lack of clear biomarkers and very heterogeneous pharmacokinetics and pharmacodynamics of analgesics. There is a clear call for integral research addressing the multimodality of pain in this population and further developing population pharmacokinetic models towards physiology-based models.

Pharmacological sedation management in the paediatric intensive care unit

Objective

This review addresses sedation management on paediatric intensive care units and possible gaps in the knowledge of optimal sedation strategies. We present an overview of the commonly used sedatives and their pharmacokinetic and pharmacodynamic considerations in children, as well as the ongoing studies in this field. Also, sedation guidelines and current sedation strategies and assessment methods are addressed.

Key findings

This review shows that evidence and pharmacokinetic data are scarce, but fortunately, there is an active research scene with promising new PK and PD data of sedatives in children using new study designs with application of advanced laboratory methods and modelling. The lack of evidence is increasingly being recognized by authorities and legislative offices such as the US Food and Drug Administration (FDA) and European Medicines Agency (EMA).

Conclusion

The population in question is very heterogeneous and this overview can aid clinicians and researchers in moving from practice-based sedation management towards more evidence- or model-based practice. Still, paediatric sedation management can be improved in other ways than pharmacology only, so future research should aim on sedation assessment and implementation strategies of protocolized sedation as well.

Children in clinical trials: towards evidence-based pediatric pharmacotherapy using pharmacokinetic-pharmacodynamic modeling

INTRODUCTION

In pediatric pharmacotherapy, many drugs are still used off-label, and their efficacy and safety is not well characterized. Different efficacy and safety profiles in children of varying ages may be anticipated, due to developmental changes occurring across pediatric life.

AREAS COVERED

Beside pharmacokinetic (PK) studies, pharmacodynamic (PD) studies are urgently needed. Validated PKPD models can be used to derive optimal dosing regimens for children of different ages, which can be evaluated in a prospective study before implementation in clinical practice. Strategies should be developed to ensure that formularies update their drug dosing guidelines regularly according to the most recent advances in research, allowing for clinicians to integrate these guidelines in daily practice. Expert commentary: We anticipate a trend towards a systems-level approach in pediatric modeling to optimally use the information gained in pediatric trials. For this approach, properly designed clinical PKPD studies will remain the backbone of pediatric research.