Premature Infant Pain Profile: development and initial validation

Pain assessment and management in the newborn infant

Managing the pain of a newborn is both complex and challenging because of the subtlety of pain expression in these patients and their vulnerability. This article provides an overview of the physiology of pain in the newborn, addresses pain assessment and pain-assessment tools, explores both nonpharmacological and pharmacological approaches to pain management, and finally, lays the responsibility for pain management in the newborn squarely in the lap of the professional.

Pain in hospitalized children: pediatric nurses' beliefs and practices

A descriptive design was used to gather information regarding nurses' beliefs and documentation practices related to pain assessment and management in children. Pediatric nurses (n = 260) from eight hospital units completed a child and pain survey. Nurses' pain-related documentations on children (n = 153) were also examined. Results showed inconsistency between what nurses believe about pain assessment and management and their documentation of practice. Nurses believed that assessment is the first step toward alleviating pain in children. However, it was not evident in their documentations that nurses used developmentally appropriate tools for assessment or for evaluation of children's responses to pain management strategies.

Validation of the premature infant pain profile in the clinical setting

OBJECTIVE

The Premature Infant Pain Profile (PIPP) is a 7-indicator composite measure developed to assess acute pain in preterm and term neonates. It has been validated in studies using synchronized videotaping of infants undergoing procedures. The purpose of this study was to establish (a) construct validity of the PIPP and (b) inter- and intrarater reliability of the PIPP prospectively in the clinical environment.

DESIGN

A randomized, crossover design was used.

SETTING

The study was conducted in a Level III outborn neonatal intensive care unit.

PARTICIPANTS

A convenience sample of 43 neonates, stratified by gestational age, was studied.

INTERVENTIONS

Each infant experienced three separate, randomly ordered events: baseline, a painful event, and a nonpain event. Infants were videotaped and scored at the bedside using the PIPP by the nurse caring for the infant and the clinical nurse specialist who bad expertise in infant pain. The videotapes were later reviewed by two additional experts; one in real time and one using a second-to-second stop frame technique.

RESULTS

Repeated-measures analysis of the main effects and interactions yielded a statistically significant main effect for event (pain, nonpain, baseline), thus differentiating pain from nonpain and baseline events (F = 48, p = 0.0001) and establishing construct validity. Interrater reliability analysis of individual event scores of the PIPP yielded reliability coefficients of 0.93-0.96. Intrarater reliability coefficients analysis for individual events were equally high at 0.94-0.98.

CONCLUSIONS

This study demonstrates that the PIPP is a pain measure with good construct validity and excellent inter- and intrarater reliability for the assessment of procedural pain of preterm and term infants in clinical settings.

Factors explaining lack of response to heel stick in preterm newborns

OBJECTIVE

To determine factors explaining lack of response by preterm newborns to heel stick for blood sampling.

DESIGN

A cross-sectional design based on secondary analysis of the control session of a randomized crossover design.

SETTING

Four Level III neonatal intensive-care units of university teaching hospitals.

PARTICIPANTS

120 preterm newborns with an average age of 28 weeks postconceptional age.

INTERVENTION

24 newborns who showed a "no change" response according the Premature Infant Pain Profile were compared to the remaining 96 newborns who had shown a pain response.

MAIN OUTCOME MEASURES

Age (postconceptional age at birth, postnatal age at study), Apgar score at 5 minutes, severity of illness, sex, race, wake/sleep state, previous study sessions, total number of painful procedures since birth, and time since last painful procedure.

RESULTS

After stepwise logistic regression analysis the variables remaining in the final model that explained the difference between the groups were postnatal age at time of study, postconceptional age at birth, time since last painful procedure, and wake/sleep state.

CONCLUSIONS

Newborns who were younger, asleep, and had undergone a painful event more recently were less likely to demonstrate behavioral and physiologic indicators of pain.

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

OBJECTIVE

The purposes of the study were threefold: (a) to determine whether a measurement system based on facial expression would be useful in the assessment of post-operative pain in young children; (b) to examine construct validity in terms of structure, consistency, and dynamics of the facial display; and (c) to evaluate concurrent validity in terms of associations with global judgments of the children's pain.

PATIENTS

One hundred children between the ages of 13 and 74 months were video-taped for a maximum of 1 hour after arrival in the postanesthesia care unit (PACU) at British Columbia's Children's Hospital.

OUTCOME MEASURES

Videotapes were edited into 20-second blocks, randomly selected from each 2-minute time period taped during the hour following surgery, and coded for the presence or absence of 13 facial actions in the Child Facial Coding System (CFCS).

RESULTS

Facial expressions were characterized primarily by the following constellation of actions: open lips, lowered brows, a deepened nasolabial furrow, mouth stretched wide in both horizontal and vertical directions, eyes squeezed shut or squinted, and raised cheeks. A principal components analysis indicated that these actions comprised a single factor, accounting for 55% of the variance in CFCS actions. Facial action summary scores were correlated with a visual analog rating of global pain, confirming that the CFCS has convergent validity. Facial action summary scores, i.e., pain displays, were at their lowest immediately after admittance to the PACU and just before the child's release from the PACU.

CONCLUSIONS

The present study demonstrated that the CFCS serves as a valid measurement tool for persistent pain in children.

Do cry features reflect pain intensity in preterm neonates? A preliminary study

The purpose of this study was to investigate if cries from preterm neonates would reflect changes in pain intensity following interventions. The cries from 25 preterm neonates from an original sample of 122 were audiorecorded while the infant was undergoing heelstick during a randomized crossover design testing the efficacy of: pacifier with sucrose or water, or prone position as compared to standard care. Both pacifier conditions reduced procedural pain according to a validated composite pain measure (the Premature Infant Pain Profile). There were proportionately fewer cries in the two pacifier groups compared to the prone positioning and standard care groups, and cry duration was positively correlated with PIPP scores. However, neither cry duration nor fundamental frequency reflected group differences. Further research is needed to determine if cry is a sensitive and valid indicator of pain in preterm infants.

Procedural pain in newborn infants: the influence of intensity and development

OBJECTIVE

Previous reports have shown that pain is managed inadequately in newborn infants. Ironically, clinicians believe that infants can experience pain much like adults, that infants are exposed daily to painful procedures, and that pain protection should be provided. In adults, a close relationship has been shown in how adults behave in response to pain, how painful they sense the stimulus to be, and physical measurements of the intensity of the stimulus. Whether similar parallels exist in newborn infants has not been examined. If these parallels do not exist in infants, it may help explain why clinicians fail to manage procedural pain in infants more effectively. The objective of this study was to determine whether the magnitude of infants' responses to nursing/medical procedures: 1) differs as a function of the invasiveness or intensity of the procedure; 2) differs as a function of intrauterine (gestational age at birth) and/or extrauterine (conceptional age) development; and 3) parallels the subjective pain ratings of clinicians for those procedures.

METHODS

A broad developmental and clinical range of newborn infants was studied shortly before (baseline and preparatory periods), throughout, and shortly after (recovery period) required nursing/medical procedures during hospitalization. Heart rate, oxygen saturation, mean arterial pressure, and behavioral state (percentage of time spent in sleep or in agitation) were measured, and the magnitude of change in each in response to procedures was calculated. Procedures were categorized as mildly, moderately, and highly invasive to examine differences in response magnitude as a function of procedural invasiveness. Responses were compared as a function of prematurity and postnatal age. Clinicians' procedural pain ratings were compared with the magnitude of infants' responses.

RESULTS

Of the original 152 infants, 135 were studied at least two times (range 2-27). Significant changes occurred in physiologic and behavioral measures in response to procedures indicative of pain responses. The magnitude of response generally increased with increased procedural invasiveness although there was considerable overlap of magnitude with invasiveness. Both premature and full-term infants differentiated procedural invasiveness. Very premature infants (<28 weeks' gestational age) exhibited increased increments in response magnitude with increasing postnatal age. Clinician's ratings of procedural painfulness were correlated with and predicted the magnitude of heart rate response to individual procedures.

CONCLUSIONS

Similar to what has been shown in adults, newborn and developing infants show increased magnitude physiologic and behavioral responses to increasingly invasive procedures, demonstrating that even very prematurely born infants respond to pain and differentiate stimulus intensity. However, the considerable overlap of magnitude with invasiveness suggests that there is not a physiologic or behavioral threshold that clearly marks the presence of pain. Inconsistencies in physiologic and behavioral responses make reliance on a pain index difficult. The best approach may be one of universal precaution to provide pain management systematically to reduce the acute and long-term impact of early procedural pain. development, stimulus intensity, pain response.

Oral glucose and venepuncture reduce blood sampling pain in newborns

The objectives of this study were to measure pain symptoms in healthy fullterm newborns undergoing routine blood sampling with different methods. The 120 study subjects were randomly allocated to one of four groups with 30 babies in each, namely venepuncture or heel stick, with or without oral glucose administration. Pain was assessed from the duration of crying within the first 3 min, the Premature Infant Pain Profile (PIPP) and changes in heart rate. When the babies received 1 ml 30% glucose prior to skin puncture there was no significant difference between the heel stick and venepuncture group either in mean crying time (12.9 and 11.6 s, respectively) or in PIPP score (3.9 and 3.3). When no glucose was given crying time was 57.3 s in the heel stick group and 26.8 s in the venepuncture group (P = 0.0041) and the mean PIPP scores were 8.4 and 6.0, respectively (P = 0.0458). This study suggests that if oral glucose is given prior to skin puncture the choice of blood sampling method has no impact on the pain symptoms.

Validity of behavioral and physiologic parameters for acute pain assessment of term newborn infants

CONTEXT

The subjectivity of pain causes enormous difficulties in evaluating neonatal pain with a single, practical and easy-to-apply tool. Pain evaluation in the neonatal period should be performed by valid, safe, useful and feasible methods.

OBJECTIVE

To evaluate the validity of the Neonatal Facial Coding System (NFCS), Neonatal Infant Pain Scale (NIPS), heart rate (HR) and O2 saturation (O2 sat) for neonatal pain assessment.

DESIGN

Prospective, double-blind randomized trial.

SETTING

A secondary level maternity hospital.

PARTICIPANTS

70 healthy neonates requiring bilirubin dosage were randomly assigned to receive a venous puncture (P: n = 33, BW 3.2 kg, SD 0.6; GA 39 wk, SD 1; 59 h of life, SD 25) or an alcohol swab friction (F: n = 37; BW 3.1 kg, SD 0.5; GA 39 wk, SD 1; 52 h of life, SD 17).

INTERVENTION

All measurements were taken prior to (PRE), during (TO), and 1 (T1), 3(T3), 5(T5) and 10(T10) minutes after the procedure.

MEASUREMENTS

A neonatologist evaluated NFCS, NIPS, HR and O2 sat by pulse oxymetry.

RESULTS

Median NFCS and NIPS results at T0, T1 and T3 were higher in P group, compared to F. More P neonates presented NFCS > 2 and/or NIPS > 3 at T0, T1 and T3. HR was lower in P group at T1. Average O2 sat was above 90% during the whole study period in both groups.

CONCLUSION

NFCS and NIPS are suitable instruments for neonatal pain evaluation. Heart rate and O2 saturation can be used only as auxiliary methods.

Pain measurement in persons with intellectual disabilities

OBJECTIVE

The goal was to study the utility of nonverbal facial expressions as a research tool for assessing pain in persons with intellectual disabilities. Biases and stereotypes related to age, gender, physical attractiveness, and intellectual disability that may influence the ability of observers to evaluate pain reactions were also examined.

DESIGN

Facial reactions to an intramuscular injection of 40 adults (mean age = 49.6 years) with an intellectual disability were videotaped and objectively examined using the Facial Action Coding System. Self-reported pain ratings were obtained using a Colored Visual Analogue Scale for pain. Pain reactions were also rated by untrained observers.

RESULTS

A significant proportion of participants (35%) was unable to provide valid self-report. The intensity of objectively coded facial activity as well as observer-rated pain intensity showed significant increases from baseline to injection segments. Observers' pain ratings were primarily determined by the intensity of facial activity and were not significantly affected by stereotypes based on perceived level of intellectual disability, gender, age, or physical attractiveness.

CONCLUSIONS

The findings support the validity of both objectively coded and observer-rated facial expressions of pain as research tools in treatment outcome studies involving persons with intellectual disabilities. Self-report has substantial limitations for the assessment of pain in this population.

Effect of repeated doses of sucrose during heel stick procedure in preterm neonates

The purpose of this randomized clinical trial was to test the efficacy of repeated versus single dose sucrose to decrease pain from routine heel stick procedures in preterm neonates. Infants (n = 48) in the first week of life with a mean gestational age of 31 weeks received 0.05 ml of 24% sucrose solution or sterile water by mouth (1) 2 min prior to actual lancing of the heel; (2) just prior to lancing, and (3) 2 min after lancing. The single-dose group received sucrose for the first dose and water for the second and third dose; the repeated-dose group received sucrose three times, and the placebo group received only water. The Premature Infant Pain Profile (PIPP) scores were obtained for five 30-second blocks from lancing. Both sucrose groups had lower PIPP scores (single sucrose pain scores, 6.8-8.2, p = 0.07; repeated sucrose pain scores, 5.3-6. 2, p < 0.01) than water (pain scores 7.9-9.1), and in the last block, the repeated dose had lower scores than the single dose (6.2 vs. 8. 2, p < 0.05).

Advantages of fentanyl over morphine in analgesia for ventilated newborn infants after birth: A randomized trial

OBJECTIVE

To compare the efficacy and adverse effects of fentanyl or morphine analgesia during the first 2 days of life in newborn infants who underwent mechanical ventilation.

STUDY DESIGN

In a randomized double-blind trial, 163 infants were allocated to receive a continuous infusion of fentanyl (10.5 microg/kg over a 1-hour period followed by 1.5 microg/kg/hr) or morphine (140 microg/kg over a 1-hour period followed by 20 microg/kg/hr) for at least 24 hours. The severity of pain was assessed with physiological parameters, a behavioral pain scale, and stress hormone concentrations before and 2 and 24 hours after the start of treatment.

RESULTS

The analgesic effect was similar in both groups, as judged by the pain scale. Plasma adrenaline and noradrenaline concentrations decreased significantly from 0 to 24 hours in both groups. Median adrenaline decrease was 0.5 nmol/L (interquartile range [IQR] 1.1;0.0) in the fentanyl and 0.7 nmol/L (IQR 1.3;0.1) in the morphine group, noradrenaline 2.1 nmol/L (IQR 9.0;0.2), and 3.0 nmol/L (IQR 7. 5;0.3), respectively. beta-endorphin decreased significantly only in the fentanyl group ( 14 pmol/L (IQR 28; 7), P <.05). Decreased gastrointestinal motility was less frequent in the fentanyl group (23% vs 47%, P <.01).

CONCLUSIONS

With at least as effective analgesia as with morphine, fentanyl had fewer side effects. Fentanyl may be superior to morphine for short-term postnatal analgesia in newborn infants.

Preverbal, Early Verbal Pediatric Pain Scale (PEPPS): development and early psychometric testing

The Pre-Verbal, Early Verbal Pediatric Pain Scale (PEPPS) is conceptualized to measure the established pain response in toddlers, a pediatric group void of pain assessment scales. It consists of seven categories, each with weighted indicators. Scores can range from 0 to 26. Using a blinded, cross-sectional design, 40 children, aged 12 to 24 months, were videotaped throughout their postoperative stay in the postanesthesia care unit. Vignettes were randomly selected and viewed by four experienced pediatric nurses. Results indicated that the PEPPS was easy to use and demonstrated acceptable inter-rater and intrarater reliability. Early evidence of construct validity was established by statistically significant differences in premedication and postmedication pain scores.

Pain in neonate

Anatomical, functional and neurochemical maturation of pain pathways is well developed in fetus and neonates. Various physiological and behavioural responses to painful stimuli in neonates substantiate their ability to feel pain. Biological effects of pain are systematically studied in human fetus and neonates. Pain expressions in the newborn not only reflect tissue damage but are a function of ongoing behavioural state. The ultimate aim should be to keep neonates free from pain and other stressful stimuli as far as possible, by advocating minimal handling protocol, giving comforts after painful procedures, local anesthesia while carrying out painful procedures like cutdown and insertion of chest tubes, and if a baby is ventilated fentanyl and/or midazalam infusion must be carried out during initial periods of ventilation.

The efficacy of developmentally sensitive interventions and sucrose for relieving procedural pain in very low birth weight neonates

BACKGROUND

Procedural pain management for very low birth weight (VLBW) neonates has been minimal or nonexistent in most neonatal intensive care units (NICUs).

OBJECTIVES

To compare the efficacy of developmentally sensitive behavioral interventions (nonnutritive sucking via a pacifier, positioning) and sucrose for relieving procedural pain in VLBW infants and to determine the influence of contextual factors (gestational age, postnatal age, birth weight, severity of illness, frequency of painful procedures) on pain response.

METHOD

In a prospective randomized crossover trial, pain was assessed in 122 VLBW neonates using the Premature Infant Pain Profile following four randomly ordered interventions during consecutive routine heel lance procedures.

RESULTS

Significant differences in pain existed among treatment interventions (F = 16.20, p < .0001). The pacifier with sucrose (F = 24.09, p < .0001) and pacifier with sterile water (F = 9.00, p = .003) significantly reduced pain. Prone positioning did not decrease pain (F = 2.24, p = .137). Frequency of painful procedures approached significance in influencing pain response (F = 3.59, p = .01).

CONCLUSIONS

The most efficacious interventions for reducing pain from single painful events were the pacifier with sucrose and the pacifier with sterile water. Research on the efficacy and safety of implementing these interventions, alone and in combination, for repeated painful procedures is needed. In addition, research is needed on the influence of implementing these interventions on pain response and clinical outcomes (e.g., health status and neurodevelopmental status) in VLBW neonates in the NICU.

Opioid tolerance in neonates: mechanisms, diagnosis, assessment, and management

Opioid tolerance and withdrawal have been challenges for decades. The neurochemical mechanisms of tolerance and dependence are clinically important only because they can affect weaning schedules and the adjustment of doses for neonates. Analgesic effects are characterized by an increased depolarization threshold for the neuron, shorter duration of the action potential generated, and reduced release of neurotransmitters. Tolerance and withdrawal are associated with the reversal of these cellular effects. Adverse clinical effects associated with the use of opioids in neonates include respiratory depression, chest wall rigidity, urinary retention, and decreased gastrointestinal motility. The physiological systems most prominently affected by opioid withdrawal include the central nervous system, gastrointestinal system, and the autonomic nervous system. Opioid withdrawal symptoms in neonates can be assessed by using easily available scoring systems, although these need to be validated for different populations. Management of opioid withdrawal includes the use of other opioids, benzodiazepines and alpha-2 adrenergic receptor antagonist, clonidine. Careful titration of opioids with attention given to appropriate weaning schedules can reduce the incidence of withdrawal in neonates.

Assessment of pain in the neonate

This article critically reviews the measures developed for assessing pain in the human neonate. Information was gathered with a computerized literature search of published articles and abstracts, a manual review of relevant conference proceedings, recently published journals, unpublished reports and manuscripts, and personal files. This identified 16 measures that were critically examined for their psychometric properties (reliability and validity) and clinical use. Special emphasis was placed on the feasibility of using neonatal pain assessment measures for clinical practice to address the research-practice gap. Although considerable progress has been made in the field of neonatal pain assessment, few measures have adequately established psychometric properties and clinical utility. Furthermore, most measures have been developed for research and not for the clinical setting. Issues regarding sensitivity, specificity, and the ability to detect clinically important changes have not been addressed. A sufficient number of infant pain measures have now been developed to assess acute pain. There is a paucity of measures to assess chronic pain in infants, and measures for infants who are low birth weight, critically ill, or ventilated. Future research should be aimed at strengthening the properties of existing measures, and at the development of measures for those infants with chronic pain or special needs.

Practical approach to analgesia and sedation in the neonatal intensive care unit

The anatomic and physiological bases for nociception are present even in very preterm neonates. Neonates show the same behavioral, endocrine, and metabolic responses to noxious stimuli as older subjects. Preterm infants appear to be more sensitive to painful stimuli and have heightened responses to successive stimuli. Infants receiving intensive care are subjected to frequent stressful procedures and also chronic noxious influences related to the environment of care. Inflammatory conditions such as necrotizing enterocolitis may also cause pain. Untreated pain in babies is associated with increased major morbidity and mortality. Nonpharmacological interventions, including environmental modification and comforting during procedures reduce stress. Intravenous opiates are the mainstay of pharmacological analgesia. A pure sedative agent can provide physiological stability in settings in which there are less acutely painful stimuli or when there are adverse effects from, or tolerance to, opiates. Local anesthesia of skin and mucous membranes is helpful for invasive procedures. Antipyretic analgesics such as acetaminophen have a role in inflammatory pain.

The interpretation of infant pain: physiological and behavioral indicators used by NICU nurses

The purpose of this descriptive study was to identify the indicators used by neonatal nurses to interpret the experience of pain in infants in a Neonatal Intensive Care Unit (NICU). A sample of 72 NICU nurses completed a structured questionnaire to identify the physiological and behavioral indicators they used to interpret the experience of pain in the infants entrusted to their care. The 10 pain indicators used by more than 50% of the nurses, listed in decreasing order of frequency, were: fussiness, restlessness, grimacing, crying, increasing heart rate, increasing respirations, wiggling, rapid state changes, wrinkling of forehead, and clenching of fist. These findings are consistent with existing literature, are compatible with the stress cues identified in Als' Synactive Theory of Development, and lend support to the use of such measures for the assessment of infant pain.

Physiological, hormonal, and behavioral responses to a single fentanyl dose in intubated and ventilated preterm neonates

OBJECTIVE

To study the responses of ventilated preterm neonates to a single dose of opioid.

STUDY DESIGN

In a randomized, double-blind, controlled trial, 22 mechanically ventilated preterm infants (< or = 32 weeks) were observed before medication and at 30 and 60 minutes after administration of fentanyl (3 micrograms/kg) or placebo. Heart rate, blood pressure, arterial blood gases, ventilator settings, and behavioral measures (Neonatal Facial Coding System and Modified Postoperative Comfort Score) were recorded during each period. Blood cortisol, growth hormone, glucose, and lactate were measured before and at 60 minutes after analgesia. Behavioral measures were assessed at the bedside and from video films recorded during each observation period.

RESULTS

Patients presented high basal levels of cortisol, growth hormone, and lactate. Behavioral scales indicated the presence of pain before any medication. In the fentanyl group, the maximum and minimum heart rate decreased and growth hormone level increased after analgesia. At the video analysis of behavioral measures, postoperative comfort score increased and neonatal facial coding system score decreased in the fentanyl group.

CONCLUSION

Single doses of fentanyl analgesia can reduce the physiologic/behavioral measures of pain and stress associated with mechanical ventilation in preterm infants.

A systematic review of lidocaine-prilocaine cream (EMLA) in the treatment of acute pain in neonates

OBJECTIVE

Neonates routinely undergo painful cutaneous procedures as part of their medical treatment. Lidocaine-prilocaine 5% cream (EMLA) is a topical anesthetic that may be useful for diminishing the pain from these procedures. EMLA is routinely used in children and adults. There is substantial apprehension about its use in neonates because of concerns that it may cause methemoglobinemia. The objective of this review was to determine the efficacy and safety of EMLA as an analgesic for procedural pain treatment in neonates and provide evidence-based recommendations for clinical practice.

METHODS

Systematic review techniques were used. Studies were identified using manual and computer-aided searches (Medline, EMBASE, Reference Update, personal files, scientific meeting proceedings). Behavioral (eg, facial action, crying) and physiologic (eg, heart rate, oxygen saturation, blood pressure, respiratory rate) outcome data from prospective nonrandomized controlled studies and randomized controlled trials in full-term and preterm neonates were accepted for inclusion to establish efficacy of EMLA. The risk of methemoglobinemia (defined as methemoglobin concentration >5% and requiring medical intervention) was estimated from all prospective studies.

RESULTS

Eleven studies of the efficacy of EMLA were included in the analysis. Infant gestational age at the time of delivery ranged from 26 weeks to full-term. Two studies included data from both neonates and older infants. The following procedures were studied: circumcision (n = 3), heel lancing (n = 4), venipuncture (n = 1), venipuncture and arterial puncture (n = 1), lumbar puncture (n = 1), and percutaneous venous catheter placement (n = 1). Nine studies were randomized controlled trials. The total sample size for each study ranged from 13 to 110 neonates. The dose of EMLA used was 0.5 g to 2 g in 9 studies, and was not specified in the others. The duration of application ranged from 10 minutes to 3 hours. The three studies that investigated the efficacy of EMLA for decreasing the pain of circumcision used a randomized controlled trial design. All of them demonstrated significantly reduced crying time during the procedure in the infants in the EMLA group compared with the infants in the control group. Facial grimacing, assessed in two of the studies, was also significantly lower in the EMLA group. Using meta-analytic techniques, the heart rate outcome data for two studies was summarized. Increases in heart rate compared with baseline values were 12 to 27 beats per minute less for the EMLA group than in the placebo group during various stages of the surgical procedure. Three studies that investigated the pain from heel lancing were randomized controlled trials; the other was a nonrandomized controlled study. None demonstrated a significant benefit of EMLA for any of the outcome measures used to assess pain (ie, behavioral pain scores, infant crying, heart rate, blood pressure, respiratory rate, oxygenation parameters). One randomized controlled study of the pain from venipuncture showed that infants treated with EMLA had significantly lower heart rates and cry duration compared with infants treated with a placebo. In one nonrandomized study, a significantly lower behavioral pain score was observed for infants treated with EMLA compared with the control group. Infant heart rate, however, did not differ between the groups. In one randomized controlled study of pain from percutaneous venous catheter placement, EMLA resulted in a significantly lower increase in heart rate and respiratory rate. Behavioral pain scores were significantly lower during arterial puncture in one nonrandomized controlled study. EMLA did not reduce physiologic changes or behavioral pain scores in one randomized controlled trial in infants undergoing lumbar puncture. Meta-analytic techniques revealed that methemoglobin concentrations did not differ between EMLA-treated and placebo-treated infants (weighted mean di

Pain assessment and documentation--making a difference

Pain assessment is essential for effective pain management. Development of structured pain assessment and documentation of the child's pain history is vital. Involving the child and family in pain assessment is crucial for effective pain management. Pain management requires multiprofessional commitment and involvement. The role of the acute pain service is a vital element within a Children's Trust.

Measurement of neonatal responses to painful stimuli: a research review

The measurement of neonatal responses to painful stimuli remains a significant clinical problem. Although numerous measures have been evaluated, instruments that are valid, reliable, and clinically feasible are not yet available. The purpose of this paper is to critique the studies that have been done using biochemical, physiological, and behavioral measures to evaluate neonatal responses to painful stimuli. Specific issues regarding measurement in premature and critically ill neonates are emphasized. The intent of this review and critique of the literature is to stimulate additional research into the assessment of neonatal pain.

Symptom management outcomes. Do they reflect variations in care delivery systems?

OBJECTIVES

Symptom management is increasingly recognized as a critical element of patient care, particularly in managing chronic illness. However, research on outcomes related to symptom management is in its infancy, except for the symptom of pain. This symptom was therefore chosen as a prototype to review the state of the science regarding relations between organizational variables and symptom management outcomes and to illustrate the issues regardless of the symptom managed. This article discusses pain outcome measures appropriate for acute and cancer pain, proposes attributes of the care delivery system that may affect outcome measures, and identifies challenges associated with this type of research.

METHODS

Review of quality assurance studies raises issues concerning the adequacy of currently used outcomes for pain and satisfaction with pain management. Although considerable effort has been expended in developing pain measurement in adults and children, critical issues for examining pain management outcomes include deciding what perspectives should be used as the most valid indicator of the pain outcome and when the measures should be obtained.

RESULTS

Critical concerns are raised about the measure of satisfaction with pain management and its appropriateness as the end-result outcome. A key issue is whether respondents actually disentangle satisfaction with pain management from satisfaction with other aspects of care, including caring dispositions of health-care providers. Finally, the question is raised: Are pain outcomes affected by organizational context?

CONCLUSIONS

Although the answer to this question is unknown, a few research studies suggest that organizational context is likely to influence pain outcomes. It is clear, however, from ongoing work that until several conceptual, methodological, and analytic challenges are resolved, research is unlikely to capture the influence of variations in care delivery systems on symptom management outcomes.

The efficacy of sucrose for relieving procedural pain in neonates--a systematic review and meta-analysis

The objective was to determine the efficacy and optimal dose of sucrose for relieving procedural pain in neonates. Data were obtained using MEDLINE, EMBASE, Reference Update and personal files and assessed for quality of the methods. Data from all randomized controlled trials where term and preterm neonates received a heelstick or venipuncture were examined for the efficacy of different sucrose doses (0.18 g, 0.24 g, 0.48 g or 0.50 g, 1.0 g) and water (placebo). The primary outcome was the proportion of time crying during 3 min after the painful stimulus. Data were combined across studies using a random effects model, adapted for use with single groups, producing a point estimate and 95% confidence interval (CI). Thirteen trials were identified; eight were rejected as data were inappropriate, non-extractable, or the primary outcome was not measured. Five studies provided data on 271 infants. The proportion of time crying did not differ between 0.18 g of sucrose and water (p > 0.05) but was significantly lower in all other sucrose groups. There were no differences in proportion of time crying between term and preterm neonates. Sucrose reduced the proportion of time crying during painful procedures in neonates. The 0.18 g dose of sucrose was ineffective. Doses of 0.24 g (2 ml of 12% sucrose solution) were most effective. A dose of 0.50 g provided no additional benefit.

Effect of neonatal circumcision on pain response during subsequent routine vaccination

BACKGROUND

Preliminary studies suggested that pain experienced by infants in the neonatal period may have long-lasting effects on future infant behaviour. The objectives of this study were to find out whether neonatal circumcision altered pain response at 4-month or 6-month vaccination compared with the response in uncircumcised infants, and whether pretreatment of circumcision pain with lidocaine-prilocaine cream (Emla) affects the subsequent vaccination response.

METHODS

We used a prospective cohort design to study 87 infants. The infants formed three groups--uncircumcised infants, and infants who had been randomly assigned Emla or placebo in a previous clinical trial to assess the efficacy of Emla cream as pretreatment for pain in neonatal circumcision. Infants were videotaped during vaccination done at the primary care physician's clinic. Videotapes were scored without knowledge of circumcision or treatment status by a research assistant who had been trained to measure infant facial action, cry duration, and visual analogue scale pain scores.

FINDINGS

Birth characteristics and infant characteristics at the time of vaccination, including age and temperament scores, did not differ significantly among groups. Multivariate ANOVA revealed a significant group effect (p < 0.001) in difference (vaccination minus baseline) values for percentage facial action, percentage cry time, and visual analogue scale pain scores. Univariate ANOVAs were significant for all outcome measures (p < 0.05): infants circumcised with placebo had higher difference scores than uncircumcised infants for percentage facial action (136.9 vs 77.5%), percentage cry duration (53.8 vs 24.7%), and visual analogue scale pain scores (5.1 vs 3.1 cm). There was a significant linear trend on all outcome measures, showing increasing pain scores from uncircumcised infants, to those circumcised with Emla, to those circumcised with placebo.

INTERPRETATION

Circumcised infants showed a stronger pain response to subsequent routine vaccination than uncircumcised infants. Among the circumcised group, preoperative treatment with Emla attenuated the pain response to vaccination. We recommend treatment to prevent neonatal circumcision pain.

Analgesia in newborns given oral glucose

There is evidence that newborn babies feel pain even at the lowest gestational ages when they can survive. Because sweet solutions such as sucrose, given orally, may relieve pain in neonates, we decided to compare the effects of two concentrations of glucose (normally used for intravenous infusions) and of breast milk in a randomized controlled trial in 120 babies requiring heel-prick tests. Glucose solutions and breast milk are readily available in the neonatal department. No other treatment was given. Our results strongly suggest that 1 ml of a 30% glucose solution given orally alleviates mild pain significantly and can be used for this purpose in newborns. Breast milk and 10% glucose did not have a similar effect.

Pain management in newborns: how far have we progressed in research and practice?

Compelling research supports the newborn infant's capacity for pain. Yet, pain is frequently underestimated and undertreated. This is a result of limited understanding of pain pathway development, immediate and long-term consequences, measurement tools and approaches, and safety and efficacy of pain-relieving interventions. This paper reviews recent research in relation to management of pain in the newborn, and presents implications for practice and future research.

Psychological barriers to optimal pain management in infants and children

OBJECTIVE

To discuss the numerous psychological barriers to optimum pain relief in infants, children, and adolescents.

DATA SOURCES

The professional and scientific literature on pediatric pain was accessed by means of Psychlit and Medline searches. Our clinical experience with patients was also used.

DATA SYNTHESES

The potential barriers to optimum management were discussed in terms of cognitive and emotional developmental barriers, perceived lack of control, children's knowledge and attitudes, and characteristics of children.

CONCLUSIONS

The psychological barriers to optimum pain relief are significant and attention to these barriers could lead to better pain management.