Neurophysiological assessment of acute pain in infants: a scoping review of research methods

Pain-related changes in crSO2 among premature infants undergoing PICC insertion

OBJECTIVE

To evaluate the effectiveness of cerebral regional oxygen saturation (crSO₂) values, measured using near-infrared spectroscopy (NIRS), in assessing pain associated with the peripherally inserted central catheter (PICC) in premature infants.

METHODS

NIRS was used to measure the crSO₂ levels of 48 premature infants with gestational age (GA) of < 32 weeks or a birth weight of < 1500 g. Premature infant pain profile (PIPP) scores, vital signs, transcutaneous oxygen tension (TcpO₂), transcutaneous carbon dioxide tension (TcpCO₂), and crSO₂ values were monitored. One-way repeated measure analysis of variance was used to compare heart rate (HR), respiratory rate (RR), blood pressure (BP), peripheral oxygen saturation (SpO₂), TcpO₂, TcpCO₂, and crSO₂ values before (Time 1), during (Time 2), and after (Time 3) PICC insertion. The correlation between the PIPP scores at Time 2 and the fluctuations (values detected at Time 2 minus those at Time 1) of SpO_2, TcpO_2, and crSO₂ were also analyzed.

RESULTS

The PIPP score at Time 2 was significantly higher than those at Times 1 and 3. HR, RR, and BP values increased (p < .05), and SpO₂ and crSO₂ levels decreased at Time 2 (p < .05) compared with those at Time 1. Stratified analysis based on GA revealed significant differences in HR, RR, and crSO₂ values between Times 1 and 2 in infants with a GA of ≥ 32 weeks. In infants with a GA < 32 weeks, significant differences were observed in HR, RR, SpO₂, BP, and crSO₂ values between Times 1 and 2. The fluctuation of the crSO₂ level was strongly correlated with the PIPP score at Time 2 (r = -0.829, p < .001). A weak correlation was observed between the PIPP score at Time 2 and TcpO₂ level fluctuation (r = 0.375, p = .009). No correlation was observed between the PIPP score at Time 2 and SpO₂ level fluctuation (r = 0.242, p = .097).

CONCLUSION

The fluctuation of crSO₂ levels strongly correlates with PICC procedural pain. Hence, crSO₂ levels measured using NIRS may be used as an indicator for pain assessment in premature infants.

Sucrose analgesia for heel-lance procedures in neonates

BACKGROUND

Sucrose has been examined for calming and pain-relieving effects in neonates for invasive procedures such as heel lance.

OBJECTIVES

To assess the effectiveness of sucrose for relieving pain from heel lance in neonates in terms of immediate and long-term outcomes SEARCH METHODS: We searched (February 2022): CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, Web of Science, and three trial registries.

SELECTION CRITERIA

We included randomised controlled trials where term and/or preterm neonates received sucrose for heel lances. Comparison treatments included water/placebo/no intervention, non-nutritive sucking (NNS), glucose, breastfeeding, breast milk, music, acupuncture, facilitated tucking, and skin-to-skin care.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. We reported mean differences (MD) with 95% confidence intervals (CI) using the fixed-effect model for continuous outcome measures. We assessed heterogeneity by the I2 test. We used GRADE to assess certainty of evidence.

MAIN RESULTS

We included 55 trials (6273 infants): 29 included term neonates, 22 included preterm neonates, and four included both. Heel lance was investigated in 50 trials; 15 investigated other minor painful procedures in addition to lancing. Sucrose vs control The evidence suggests that sucrose probably results in a reduction in PIPP scores compared to the control group at 30 seconds (MD -1.74 (95% CI -2.11 to -1.37); I2 = 62%; moderate-certainty evidence) and 60 seconds after lancing (MD -2.14, 95% CI -3.34 to -0.94; I2 = 0%; moderate-certainty evidence). The evidence is very uncertain about the effects of sucrose on DAN scores compared to water at 30 seconds after lancing (MD -1.90, 95% CI -8.58 to 4.78; heterogeneity not applicable (N/A); very low-certainty evidence). The evidence suggests that sucrose probably results in a reduction in NIPS scores compared to water immediately after lancing (MD -2.00, 95% CI -2.42 to -1.58; heterogeneity N/A; moderate-certainty evidence). Sucrose vs NNS The evidence is very uncertain about the effect of sucrose on PIPP scores compared to NNS during the recovery period after lancing (MD 0.60, 95% CI -0.30 to 1.50; heterogeneity not applicable; very low-certainty evidence) and on DAN scores at 30 seconds after lancing (MD -1.20, 95% CI -7.87 to 5.47; heterogeneity N/A; very low-certainty evidence). Sucrose + NNS vs NNS The evidence is very uncertain about the effect of sucrose + NNS on PIPP scores compared to NNS during lancing (MD -4.90, 95% CI -5.73 to -4.07; heterogeneity not applicable; very low-certainty evidence) and during recovery after lancing (MD -3.80, 95% CI -4.47 to -3.13; heterogeneity N/A; very low-certainty evidence). The evidence is very uncertain about the effects of sucrose + NNS on NFCS scores compared to water + NNS during lancing (MD -0.60, 95% CI -1.47 to 0.27; heterogeneity N/A; very low-certainty evidence). Sucrose vs glucose The evidence suggests that sucrose results in little to no difference in PIPP scores compared to glucose at 30 seconds (MD 0.26, 95% CI -0.70 to 1.22; heterogeneity not applicable; low-certainty evidence) and 60 seconds after lancing (MD -0.02, 95% CI -0.79 to 0.75; heterogeneity N/A; low-certainty evidence). Sucrose vs breastfeeding The evidence is very uncertain about the effect of sucrose on PIPP scores compared to breastfeeding at 30 seconds after lancing (MD -0.70, 95% CI -0.49 to 1.88; I2 = 94%; very low-certainty evidence). The evidence is very uncertain about the effect of sucrose on COMFORTneo scores compared to breastfeeding after lancing (MD -2.60, 95% CI -3.06 to -2.14; heterogeneity N/A; very low-certainty evidence). Sucrose vs expressed breast milk The evidence suggests that sucrose may result in little to no difference in PIPP-R scores compared to expressed breast milk during (MD 0.3, 95% CI -0.24 to 0.84; heterogeneity not applicable; low-certainty evidence) and at 30 seconds after lancing (MD 0.3, 95% CI -0.11 to 0.71; heterogeneity N/A; low-certainty evidence). The evidence suggests that sucrose probably may result in slightly increased PIPP-R scores compared to expressed breast milk 60 seconds after lancing (MD 1.10, 95% CI 0.34 to 1.86; heterogeneity N/A; low-certainty evidence). The evidence is very uncertain about the effect of sucrose on DAN scores compared to expressed breast milk 30 seconds after lancing (MD -1.80, 95% CI -8.47 to 4.87; heterogeneity N/A; very low-certainty evidence). Sucrose vs laser acupuncture There was no difference in PIPP-R scores between sucrose and music groups; however, data were reported as medians and IQRs. The evidence is very uncertain about the effect of sucrose on NIPS scores compared to laser acupuncture during lancing (MD -0.86, 95% CI -1.43 to -0.29; heterogeneity N/A; very low-certainty evidence). Sucrose vs facilitated tucking The evidence is very uncertain about the effect of sucrose on total BPSN scores compared to facilitated tucking during lancing (MD -2.27, 95% CI -4.66 to 0.12; heterogeneity N/A; very low-certainty evidence) and during recovery after lancing (MD -0.31, 95% CI -1.72 to 1.10; heterogeneity N/A; very low-certainty evidence). Sucrose vs skin-to-skin + water (repeated lancing) The evidence suggests that sucrose results in little to no difference in PIPP scores compared to skin-to-skin + water at 30 seconds after 1st (MD 0.13, 95% CI -0.70 to 0.96); 2nd (MD -0.56, 95% CI -1.57 to 0.45); or 3rd lancing (MD-0.15, 95% CI -1.26 to 0.96); heterogeneity N/A, low-certainty evidence for all comparisons. The evidence suggests that sucrose results in little to no difference in PIPP scores compared to skin-to-skin + water at 60 seconds after 1st (MD -0.61, 95% CI -1.55 to 0.33); 2nd (MD -0.12, 95% CI -0.99 to 0.75); or 3rd lancing (MD-0.40, 95% CI -1.48 to 0.68); heterogeneity N/A, low-certainty evidence for all comparisons. Minor adverse events required no intervention.

AUTHORS' CONCLUSIONS

Sucrose compared to control probably results in a reduction of PIPP scores 30 and 60 seconds after single heel lances (moderate-certainty evidence). Evidence is very uncertain about the effect of sucrose compared to NNS, breastfeeding, laser acupuncture, facilitated tucking, and the effect of sucrose + NNS compared to NNS in reducing pain. Sucrose compared to glucose, expressed breast milk, and skin-to-skin care shows little to no difference in pain scores. Sucrose combined with other nonpharmacologic interventions should be used with caution, given the uncertainty of evidence.

Analgesic Electrical Stimulation Combined with Wrist-Ankle Acupuncture Reduces the Cortical Response to Pain in Patients with Myofasciitis: A Randomized Clinical Trial

OBJECTIVE

Transcutaneous electrical nerve stimulation (TENS) based on wrist-ankle acupuncture has been shown to relieve pain levels in patients with myofascial pain syndrome (MPS). However, its efficacy is highly subjective. The purpose of this study was to evaluate the feasibility and effectiveness of TENS based on wrist-ankle acupuncture for pain management in patients with MPS from the perspective of cerebral cortex hemodynamics.

DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS

We designed a double-blind, randomized, controlled clinical trial. Thirty-one male patients with MPS were randomly assigned to two parallel groups. The experimental group (n = 16) received TENS based on wrist-ankle acupuncture for analgesic treatment, while the control group (n = 15) did not. The pain was induced by mechanically pressurized at acupoint Jianjing. The multichannel functional near-infrared spectroscopy (fNIRS) equipment was utilized for measuring oxyhemoglobin (HbO) levels in the cerebral cortex during the tasks.

RESULTS

After the intervention, visual analog scale (VAS), the activation degree and activation area of pain perception cortices were significantly reduced in the experimental group compared to the baseline values (P < .05). Particularly, Frontopolar Area (FPA), and Dorsolateral Prefrontal Cortex (DLPFC) are highly involved in the pain process and pain modulation.

CONCLUSION

Compared to no intervention, TENS based on wrist-ankle acupuncture can be effective in relieving pain in patients with MPS in terms of cerebral cortical hemodynamics. However, further studies are necessary to quantify the analgesic effect in terms of cerebral hemodynamics and brain activation.

Assessment of neonatal pain: uni- and multidimensional evaluation scales

Neonatal pain is a problem that is easily overlooked. According to the status quo of neonatal pain management, commonly 9 scales are used for evaluation of neonatal pain; details of the specific indicators, such as the applicable neonatal gestational age range, score, and the type of pain, for the domestic references are provided so as to provide reference for the proper evaluation and standardized management of neonatal pain, as well as to promote the management level of neonatal pain.

Functional near-infrared spectroscopy to assess pain in neonatal circumcisions

INTRODUCTION

Pain assessment is challenging in neonates. Behavioral and physiological pain scales do not assess neocortical nociception, essential to pain encoding and central pain pathway development. Functional near-infrared spectroscopy (fNIRS) can assess neocortical activation to noxious stimuli from changes in oxy-(HbO) and total-hemoglobin concentrations (HbT). This study aims to assess fNIRS nociceptive functional activation in the prefrontal cortex of neonates undergoing circumcision through changes in HbO and HbT, and the correlation between changes in fNIRS and Neonatal Infant Pain Scale (NIPS), a behavioral pain assessment scale.

METHODS

In healthy term neonates, HbO, HbT, and NIPS were recorded during sequential circumcision events 1-Prep before local anesthetic injection; 2-Local anesthetic injection; 3-Prep before incision; 4-Oral sucrose; 5-Incision; 6-Gomco (hemostatic device) attached; 7-Gomco twisted on; and 8-Gomco removed. fNIRS and NIPS changes after each event were assessed with Wilcoxon signed-rank test and summarized as median and interquartile range (IQR). Changes in fNIRS vs. NIPS were correlated with Spearman coefficient.

RESULTS

In 31 neonates fNIRS increased (median [IQR] µmol/L) with noxious events: Local injection (HbO: 1.1 [0.5, 3.1], p < .001; HbT: 2.3 [0.2, 7.6], p < .001), Gomco attached (HbO: 0.7 [0.1, 1.7], p = .002; HbT: 0.7 [-0.2, 2.9], p = .02), and Gomco twisted on (HbO: 0.5 [-0.2, 1.7], p = .03; HbT: 0.8 [-0.1, 3.3], p = .02). fNIRS decreased with non-noxious event: Prep before incision (HbO: -0.6 [-1.2, -0.2] p < .001; HbT: -1 [-1.8, -0.4], p < .001). Local anesthetic attenuated fNIRS increases to subsequent sharp stimuli. NIPS increased with subsequent sharp stimuli despite local anesthetic. Although fNIRS and NIPS changed in the same direction, there was not a strong correlation between them.

CONCLUSIONS

During neonatal circumcision, changes in fNIRS differed between different types of painful stimuli, which was not the case for NIPS, suggesting that fNIRS may complement NIPS to assess the quality of pain.

Electroencephalogram-derived pain index for evaluating pain during labor

Background

The discriminative ability of a point-of-care electroencephalogram (EEG)-derived pain index (Pi) for objectively assessing pain has been validated in chronic pain patients. The current study aimed to determine its feasibility in assessing labor pain in an obstetric setting.

Methods

Parturients were enrolled from the delivery room at the department of obstetrics in a tertiary hospital between February and June of 2018. Pi values and relevant numerical rating scale (NRS) scores were collected at different stages of labor in the presence or absence of epidural analgesia. The correlation between Pi values and NRS scores was analyzed using the Pearson correlation analysis. The receiver operating characteristic (ROC) curve was plotted to estimate the discriminative capability of Pi to detect labor pain in parturients.

Results

Eighty paturients were eligible for inclusion. The Pearson correlation analysis exhibited a positive correlation between Pi values and NRS scores in parturients (r = 0.768, P < 0.001). The ROC analysis revealed a cut-off Pi value of 18.37 to discriminate between mild and moderate-to-severe labor pain in parturients. Further analysis indicated that Pi values had the best diagnostic accuracy reflected by the highest area under the curve (AUC) of 0.857, with a sensitivity and specificity of 0.767 and 0.833, respectively, and a Youden index of 0.6. Subgroup analyses further substantiated the correlations between Pi values and NRS scores, especially in parturients with higher pain intensity.

Conclusion

This study indicates that Pi values derived from EEGs significantly correlate with the NRS scores, and can serve as a way to quantitatively and objectively evaluate labor pain in parturients.

Cortical hemodynamic activity and pain perception during insertion of feeding tubes in preterm neonates: a randomized controlled cross-over trial

OBJECTIVE

The present study evaluated the pain perception in preterm neonates during insertion of orogastric (OG) vs. nasogastric (NG) tube by measuring the cerebral regional oxygen saturation (crSO2) and premature infant pain profile-revised (PIPP-R) score.

STUDY DESIGN

Randomized controlled cross-over trial.

RESULTS

Fifty infants of mean (SD) gestational age of 31.54(2) and 31.64(2.2) weeks, birth weight of 1362(354) and 1507(365) grams were randomized into OG/NG (n = 25) and NG/OG (n = 25) sequences. Mean post-menstrual age at assessment was 33(2.8) and 33(1.5) weeks, and the difference between two interventions was 1.08(0.5) and 1.12(0.5) days in OG-NG and NG-OG, respectively. Mean crSO2(%) during insertion was significantly lower with NG compared to OG route. Mean PIPP-R score, heart rate variability, time to normalize crSO2, and the duration of cry were also significantly higher with NG insertion.

CONCLUSIONS

Compared to OG, NG route of feeding tube insertion was associated with higher fluctuations in crSO2 and higher PIPP-R scores.

CLINICAL TRIAL REGISTRY OF INDIA (CTRI) REGISTRATION NO

CTRI/2020/03/023728.

Use of glucose for pain management in premature neonates: a systematic review and meta-analysis protocol

INTRODUCTION

Therapeutic management of neonatal pain is essential to reduce changes in initial and subsequent development. Although glucose has been shown to be effective in relieving pain, concentrations and dosages remain to be standardised. The objective of this systematic review and meta-analysis is to identify the efficacy of glucose as an analgesic in preterm infants.

METHODS AND ANALYSIS

The Web of Science, Science Direct, Scopus, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, PubMed, Medline, Latin American and Caribbean Health Sciences Literature and Embase databases will be researched for randomised studies published until December 2021. This systematic review and meta-analysis will include studies investigating the use of glucose for pain control in premature neonates. The primary outcome will be pain relief. Three independent reviewers will select the studies and extract the data from original publications. The risk of bias was assessed using the Cochrane risk of bias tool. Data synthesis will be performed using the Review Manager software (RevMan V.5.2.3). We will evaluate heterogeneity based on I2 statistics. In addition, quantitative synthesis will be performed if the included studies are sufficiently homogeneous.

ETHICS AND DISSEMINATION

Ethical approval for the research will not be required for this systematic review. The results of this study will be published in an international journal.

TRIAL REGISTRATION NUMBER

This protocol was submitted to the International Prospective Register of Systematic Reviews (PROSPERO, number CRD42021236217).

Shedding light on pain for the clinic: a comprehensive review of using functional near-infrared spectroscopy to monitor its process in the brain

ABSTRACT

Pain is a complex experience that involves sensation, emotion, and cognition. The subjectivity of the traditional pain measurement tools has expedited the interest in developing neuroimaging techniques to monitor pain objectively. Among noninvasive neuroimaging techniques, functional near-infrared spectroscopy (fNIRS) has balanced spatial and temporal resolution; yet, it is portable, quiet, and cost-effective. These features enable fNIRS to image the cortical mechanisms of pain in a clinical environment. In this article, we evaluated pain neuroimaging studies that used the fNIRS technique in the past decade. Starting from the experimental design, we reviewed the regions of interest, probe localization, data processing, and primary findings of these existing fNIRS studies. We also discussed the fNIRS imaging's potential as a brain surveillance technique for pain, in combination with artificial intelligence and extended reality techniques. We concluded that fNIRS is a brain imaging technique with great potential for objective pain assessment in the clinical environment.

Available Instruments to Assess Pain in Infants

Pain assessment in newborns and infants is challenging for clinicians. Although behavioral and behavioral-physiological scales are validated pain assessment instruments, their use in this age group has significant limitations. In this review, we summarize the methods currently available for assessing pain in neonates and infants. It is possible that these pain detection methods are also useful for assessing the quality of anesthesia and analgosedation in these populations. Further research should be aimed at confirming the usefulness of these tools in infants and identifying additional pain assessment options for clinical practice.

Sedoanalgesia in neonatal units

Pain recognition and management continues to be a challenge for health professionals in Neonatal Intensive Care Units. Many of the patients are routinely exposed to repeated painful experiences with demonstrated short- and long-term consequences. Preterm babies are a vulnerable high-risk population. Despite international recommendations, pain remains poorly assessed and managed in many Neonatal Intensive Care Units. Due to there being no general protocol, there is significant variability as regards the guidelines for the approach and treatment of pain between the different Neonatal Intensive Care Units. The objective of this article is to review and assess the general principles of pain in the initial stages of development, its recognition through the use of standardised scales. It also includes its prevention and management with the combination of pharmacological and non-pharmacological measures, as well as to establish recommendations that help alleviate pain in daily clinical practice by optimising pain and stress control in the Neonatal Intensive Care Units.

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.

Can Event-Related Potentials Evoked by Heel Lance Assess Pain Processing in Neonates? A Systematic Review

To clarify the possibility of event-related potential (ERP) evoked by heel lance in neonates as an index of pain assessment, knowledge acquired by and problems of the methods used in studies on ERP evoked by heel lance in neonates were systematically reviewed, including knowledge about Aδ and C fibers responding to noxious stimuli and Aβ fibers responding to non-noxious stimuli. Of the 863 reports searched, 19 were selected for the final analysis. The following points were identified as problems for ERP evoked by heel lance in neonates to serve as a pain assessment index: (1) It is possible that the ERP evoked by heel lance reflected the activation of Aβ fibers responding to non-noxious stimuli and not the activation of Aδ or C fibers responding to noxious stimulation; (2) Sample size calculation was presented in few studies, and the number of stimulation trials to obtain an averaged ERP was small. Accordingly, to establish ERP evoked by heel lance as a pain assessment in neonates, it is necessary to perform a study to clarify ERP evoked by Aδ- and C-fiber stimulations accompanied by heel lance in neonates.

Practical approaches to sedation and analgesia in the newborn

The prevention, assessment, and treatment of neonatal pain and agitation continues to challenge clinicians and researchers. Substantial progress has been made in the past three decades, but numerous outstanding questions remain. In this setting, clinicians must establish safe and compassionate standardized practices that consider available efficacy data, long-term outcomes, and research gaps. Novel approaches with limited data must be carefully considered against historic standards of care with robust data suggesting limited benefit and clear adverse effects. This review summarizes available evidence while suggesting practical clinical approaches to pain assessment and avoidance, procedural analgesia, postoperative analgesia, sedation during mechanical ventilation and therapeutic hypothermia, and the issues of tolerance and withdrawal. Further research in all areas represents an urgent priority for optimal neonatal care. In the meantime, synthesis of available data offers clinicians challenging choices as they balance benefit and risk in vulnerable critically ill neonates.

Effectiveness of Gentle Human Touch for Pain Control During Examination for Retinopathy of Pre-maturity: A Randomized Controlled Trial

Background: Retinopathy of pre-maturity (ROP) is a disorder of the retinal blood vessels in pre-term infants with low birth weight. It is a leading cause of blindness in children. During ROP screening, the use of mydriatic drops and eyelid openers causes pain and discomfort. Pain management strategies include medications and behavioral interventions. The objectives of this study was to investigate the effects of Gentle Human Touch on pain in pre-term infants undergoing screening for ROP. Methods: In this randomized controlled trial, 82 infants in the neonatal intensive care unit at Children's Hospital of Nanjing Medical University who met the ROP screening criteria were randomly assigned to experimental and control groups using the random number table. The infants in the experimental group continuously received Gentle Human Touch during screening, while those in the control group were screened according to the routine procedure. All neonates were administered local eye anesthesia before the screening. The degree of pain was assessed using the Pre-mature Infant Pain Profile score. A double-channel near-infrared spectroscopy device was used to monitor regional cerebral oxygen saturation (rScO2), while oxygen saturation (SaO2) and heart rate were measured using pulse oximetry. The Pre-mature Infant Pain Profile score was the primary outcome, while heart rate, SaO2, and rScO2 were the secondary outcomes. Results: The gestational age, corrected gestational age, birth weight, and Apgar score at examination and the basal heart rate, SaO2, and rScO2 showed no significant intergroup differences (P > 0.05 for all). Both groups demonstrated significant decreases in SaO2 and rScO2 in response to the examination (P < 0.05 for all). During the examination, the Pre-mature Infant Pain Profile score (14.82 ± 3.22 vs. 9.29 ± 2.89, respectively; P < 0.05) was significantly higher in the control group than in the experimental group, while rScO2 (57.61 ± 3.51 vs. 54.76 ± 4.54%, respectively; P < 0.05) and SaO2 (91.89 ± 6.43 vs. 85.68 ± 8.31%; P < 0.05) were significantly higher in the experimental group than in the control group. There was no significant difference in heart rate changes between the two groups before and after the examination (182.60 ± 3.50 vs. 170.80 ± 3.50 time/min; P > 0.05). Conclusions: The findings of this study suggest that Gentle Human Touch can effectively alleviate pain during ROP screening in pre-mature infants. Clinical Trial Registration: ISRCTN10976481, Registered 06 March 2020, Retrospectively registered.

Physiological Measures of Acute and Chronic Pain within Different Subject Groups: A Systematic Review

Results

The methods' heart rate variability and electroencephalogram show clear and consistent results as acute pain assessment. Magnetic resonance imaging can measure chronic pain. Ordered by invasiveness and vulnerability, a trend shows that the invasive methods are used more with less vulnerable subjects. Only instruments used for skin conductance and automatic facial recognition have a lower-than-average technological maturity.

Conclusions

Some pain assessment methods show good and consistent results and have high technological maturity; however, using them as pain assessment for persons with ID is uncommon. Since this addition can ameliorate caregiving, more research of assessment methods should occur.

Sustained efficacy of kangaroo care for repeated painful procedures over neonatal intensive care unit hospitalization: a single-blind randomized controlled trial

Preterm neonates hospitalized in the neonatal intensive care unit undergo frequent painful procedures daily, often without pain treatment, with associated long-term adverse effects. Maternal-infant skin-to-skin contact, or kangaroo care (KC), and sweet-tasting solutions such as sucrose are effective strategies to reduce pain during a single procedure; however, evidence of sustained efficacy over repeated procedures is limited. We aimed to determine the relative sustained efficacy of maternal KC, administered alone or in combination with 24% sucrose, to reduce behavioral pain intensity associated with routine neonatal procedures, compared with 24% sucrose alone. Stable preterm infants (n = 242) were randomized to receive KC and water, KC and 24% sucrose, or 24% sucrose before all routine painful procedures throughout their neonatal intensive care unit stay. Pain intensity, determined using the Premature Infant Pain Profile, was measured during 3 medically indicated heel lances distributed across hospitalization. Maternal and neonatal baseline characteristics, Premature Infant Pain Profile scores at 30, 60, or 90 seconds after heel lance, the distribution of infants with pain scores suggesting mild, moderate, or severe pain, Neurobehavioral Assessment of the Preterm Infant scores, and incidence of adverse outcomes were not statistically significantly different between groups. Maternal KC, as a pain-relieving intervention, remained efficacious over time and repeated painful procedures without evidence of any harm or neurological impact. It seemed to be equally effective as 24% oral sucrose, and the combination of maternal KC and sucrose did not seem to provide additional benefit, challenging the existing recommendation of using sucrose as the primary standard of care.

Alterations of distributed neuronal network oscillations during acute pain in freely-moving mice

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Injection of capsaicine in mice causes prolonged acute pain and characteristic changes in neuronal network oscillations.

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Changes are most prominent in higher-order phenomena like interregional oscillation coherence.

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Power in standard frequency bands is largely unaltered.

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Behavioral states related to acute pain can be predicted from network activity by a logistic regression classifier.

The experience of pain involves the activation of multiple brain areas. Pain-specific activity patterns within and between these local networks remain, however, largely unknown. We measured neuronal network oscillations in different relevant regions of the mouse brain during acute pain, induced by subcutaneous injection of capsaicin into the left hind paw. Field potentials were recorded from primary somatosensory cortex, anterior cingulate cortex (ACC), posterior insula, ventral posterolateral thalamic nucleus, parietal cortex, central nucleus of the amygdala and olfactory bulb. Analysis included power spectra of local signals as well as interregional coherences and cross-frequency coupling (CFC). Capsaicin injection caused hypersensitivity to mechanical stimuli for at least one hour. At the same time, CFC between low (1−12 Hz) and fast frequencies (80−120 Hz) was increased in the ACC, as well as interregional coherence of low frequency oscillations (< 30 Hz) between several networks. However, these changes were not significant anymore after multiple comparison corrections. Using a variable selection method (elastic net) and a logistic regression classifier, however, the pain state was reliably predicted by combining parameters of power and coherence from various regions. Distinction between capsaicin and saline injection was also possible when data were restricted to frequencies <30 Hz, as used in clinical electroencephalography (EEG). Our findings indicate that changes of distributed brain oscillations may provide a functional signature of acute pain or pain-related alterations in activity.

Pain Scales in Neonates Receiving Mechanical Ventilation in Neonatal Intensive Care Units - Systematic Review

INTRODUCTION

Recently, interest in the problem of proper prevention and monitoring of pain, especially acute, has been increasing in relation to various age groups. Greater awareness of the problem prompts discussion about the purpose of analgesia in newborns treated with mechanical ventilation.

AIM

The purpose of the systematic review was to analyze current research on the use of pain scales in newborns treated with mechanical ventilation in the Neonatal Intensive Care Unit.

METHODS

Medline databases: PubMed, OVID, EBSCO, Web of Science and Cochrane Library were traced using the appropriate keywords. The search was limited to studies in English. The review took into account the years 2006-2019. Considering the criteria, 12 articles were included in further analysis, to which full access was obtained.

RESULTS

The analyzed scientific research showed differences in beliefs about the validity and credibility of the scales used. Researchers indicated that staff with practical experience in using scales in their daily practice was very skeptical of the results obtained on their basis.

CONCLUSION

Based on this review, no explicit evidence can be obtained to support the use of one proper scale in pain assessment. It can be inferred that the COMFORT and N-PASS scales are effective for pain assessment and for determining the need for analgesics in mechanically ventilated neonates. These scales may be equally effective in assessing chronic pain, especially in mechanically ventilated children. On the other hand, the PIPP and CRIES scales are most commonly recommended for assessing acute and postoperative pain.

The influence of pain, agitation, and their management on the immature brain

Preterm infants are exposed to frequent painful procedures and agitating stimuli over the many weeks of their hospitalization in the neonatal intensive care unit (NICU). The adverse neurobiological impact of pain and stress in the preterm infant has been well documented, including neuroimaging and neurobehavioral outcomes. Although many tools have been validated to assess acute pain, few methods are available to assess chronic pain or agitation (a clinical manifestation of neonatal stress). Both nonpharmacologic and pharmacologic approaches are used to reduce the negative impact of pain and agitation in the preterm infant, with concerns emerging over the adverse effects of analgesia and sedatives. Considering benefits and risks of available treatments, units must develop a stepwise algorithm to prevent, assess, and treat pain. Nonpharmacologic interventions should be consistently utilized prior to mild to moderately painful procedures. Sucrose may be utilized judiciously as an adjunctive therapy for minor painful procedures. Rapidly acting opioids (fentanyl or remifentanil) form the backbone of analgesia for moderately painful procedures. Chronic sedation during invasive mechanical ventilation represents an ongoing challenge; appropriate containment and an optimal environment should be standard; when indicated, low-dose morphine infusion may be utilized cautiously and dexmedetomidine infusion may be considered as an emerging adjunct.

Assessment of Pain in the Newborn: An Update

Preterm and term neonate pain assessment in neonatal intensive care units is vitally important because of the prevalence of procedural and postoperative pain. Of the 40 plus tools available, a few should be chosen for different populations and contexts (2 have been validated in premature infants). Preterm neonates do not display pain behaviors and physiologic indicators as reliably and specifically as full-term infants, and are vulnerable to long-term sequelae of painful experiences. Brain-oriented approaches may become available in the future; meanwhile, neonatal pain assessment tools must be taught, implemented, and their use optimized for consistent, reproducible, safe, and effective treatment.

Assessment of pain in newborn infants

Hospitalized newborn infants experience pain that can have negative short- and long-term consequences and thus should be prevented and treated. National and international guidelines state that adequate pain management requires valid pain assessment. Nociceptive signals cause a cascade of physical and behavioral reactions that alone or in combination can be observed and used to assess the presence and intensity of pain. Units that are caring for newborn infants must adopt sufficient pain assessment tools to cover the gestational ages and pain types that occurs in their setting. Pain assessment should be performed on a regular basis and any detection of pain should be acted on. Future research should focus on developing and validating pain assessment tools for specific situations.

A Mini-Review on Functional Near-Infrared Spectroscopy (fNIRS): Where Do We Stand, and Where Should We Go?

This mini-review is aimed at briefly summarizing the present status of functional near-infrared spectroscopy (fNIRS) and predicting where the technique should go in the next decade. This mini-review quotes 33 articles on the different fNIRS basics and technical developments and 44 reviews on the fNIRS applications published in the last eight years. The huge number of review articles about a wide spectrum of topics in the field of cognitive and social sciences, functional neuroimaging research, and medicine testifies to the maturity achieved by this non-invasive optical vascular-based functional neuroimaging technique. Today, fNIRS has started to be utilized on healthy subjects while moving freely in different naturalistic settings. Further instrumental developments are expected to be done in the near future to fully satisfy this latter important aspect. In addition, fNIRS procedures, including correction methods for the strong extracranial interferences, need to be standardized before using fNIRS as a clinical tool in individual patients. New research avenues such as interactive neurosciences, cortical activation modulated by different type of sport performance, and cortical activation during neurofeedback training are highlighted.

Multi-modal pain assessment: are near-infrared spectroscopy, skin conductance, salivary cortisol, physiologic parameters, and Neonatal Facial Coding System interrelated during venepuncture in healthy, term neonates?

Background

Improving pain and stress assessments in neonates remains important in preventing the short- and long-term consequences. We aimed to identify the relationships between different pain assessment parameters by simultaneously measuring changes in cortical, autonomic, hormonal, physiological, and behavioral evoked responses to venepuncture in healthy, full-term neonates.

Methods

This observational, prospective study (ancillary to the ACTISUCROSE trial) included 113 healthy, 3-day old, full-term neonates who underwent venepuncture for systematic neonatal screening, from July to October 2013, in a tertiary-level maternity ward of a university hospital. During venepuncture, we simultaneously measured the cortical single-channel near-infrared spectroscopy (NIRS) signals, foot skin conductance, salivary cortisol, physiological responses, and behavioral (Neonatal Facial Coding System [NFCS]) evoked responses.

Results

Regarding the NIRS analysis, the highest correlation was between the NFCS at venepuncture and the change in NIRS integrated values of total hemoglobin (r=0.41, P<0.001) or oxygenated hemoglobin (r=0.27, P<0.001). The NFCS at venepuncture was moderately positively correlated with changes in salivary cortisol (r=0.42, P<0.001) and skin conductance (r=0.29, P<0.001). Salivary cortisol and skin conductance changes were not correlated; the latter parameters were not correlated with heart rate, respiratory rate, or SpO2.

Conclusion

During venepuncture, NFCS was mildly or moderately correlated with salivary cortisol, skin conductance, and cortical NIRS changes.

Pain assessment practices in Swedish and Norwegian neonatal care units

BACKGROUND

The use of measurement scales to assess pain in neonates is considered a prerequisite for effective management of pain, but these scales are still underutilised in clinical practice.

AIM

The aim of this study was to describe and compare pain assessment practices including the use of pain measurement scales in Norwegian and Swedish neonatal care units.

METHODS

A unit survey investigating practices regarding pain assessment and the use of pain measurement scales was sent to all neonatal units in Sweden and Norway (n = 55). All Norwegian and 92% of Swedish units responded.

RESULTS

A majority of the participating units (86.5%) assessed pain. Swedish units assessed and documented pain and used pain measurement scales more frequently than Norwegian units. The most frequently used scales were different versions of Astrid Lindgren's Pain Scale (ALPS) in Sweden and Echelle Douleur Inconfort Noveau-Ne (EDIN), ALPS and Premature Infant Pain Profile (PIPP) in Norway. Norwegian head nurses had more confidence in their pain assessment method and found the use of pain measurement scales more important than their Swedish colleagues.

CONCLUSION

The persisting difference between Swedish and Norwegian units in pain assessment and the use of pain measurement scales are not easily explained. However, the reported increased availability and reported use of pain measurement scales in neonatal care units in both countries may be seen as a contribution towards better awareness and recognition of pain, better pain management and potentially less suffering for vulnerable neonates.