Celeste Johnston

Premature Infant Pain Profile: development and initial validation.

OBJECTIVE Inadequate assessment of pain in premature infants is a persistent clinical problem. The objective of this research was to develop and validate a measure for assessing pain in premature infants that could be used by both clinicians and researchers. DESIGN The Premature Infant Pain Profile (PIPP) was developed and validated using a prospective and retrospective design. Indicators of pain were identified from clinical experts and the literature. Indicators were retrospectively tested using four existing data sets. PATIENTS AND SETTINGS Infants of varying gestational ages undergoing different painful procedures from three different settings were utilized to develop and validate the measure. METHODS AND RESULTS The largest data set (n = 124) was used to develop the PIPP. The development process included determining the factor structure of the data, developing indicators and indicator scales and establishing internal consistency. The remaining three data sets were utilized to establish beginning construct validity. CONCLUSIONS The PIPP is a newly developed pain assessment measure for premature infants with beginning content and construct validity. The practicality and feasibility for using the PIPP in clinical practice will be determined in prospective research in the clinical setting.

Neonatal facial and cry responses to invasive and non-invasive procedures

&NA; Evaluation of pain in neonates is difficult due to their limited means of communication. The aim was to determine whether behavioural reactions of cry and facial activity provoked by an invasive procedure could be discriminated from responses to non‐invasive tactile events. Thirty‐six healthy full‐term infants (mean age 2.2 h) received 3 procedures in counterbalanced order: intramuscular injection, application of triple dye to the umbilical stub, and rubbing thigh with alcohol. Significant effects of procedure were found for total face activity and latency to face movement. A cluster of facial actions comprised of brow bulging, eyes squeezed shut, deepening of the naso‐labial furrow and open mouth was associated most frequently with the invasive procedure. Comparisons between the 2 non‐invasive procedures showed more facial activity to thigh swabbing and least to application of triple dye to the umbilical cord. Acoustic analysis of cry showed statistically significant differences across procedures only for latency to cry and cry duration for the group as a whole. However, babies who cried to two procedures showed higher pitch and greater intensity to the injection. There were no significant differences in melody, dysphonation, or jitter. Methodological difficulties for investigators in this area were examined, including criteria for the selection of cries for analysis, and the logical and statistical challenges of contrasting cries induced by different conditions when some babies do not always cry. It was concluded that facial expression, in combination with short latency to onset of cry and long duration of first cry cycle typifies reaction to acute invasive procedures.

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.

Acute pain response in infants: a multidimensional description.

&NA; Fourteen infants who were undergoing routine immunization were studied from a multidimensional perspective. The measures used were heart rate, crying, body movement/posturing, and voice spectrographs. There was wide variability between infants on the measures, especially on the cry spectrographs, although facial expression was consistent across infants. The pattern that did emerge was characterized by an initial response: a drop in heart rate, a long, high pitched cry followed by a period of apnea, rigidity of the torso and limbs, and a facial expression of pain. This was followed by a sharp increase in heart rate, lower pitched, but dysphonated cries, less body rigidity, but still facial expression was of pain. Finally, in the second half of the minutes response, heart rate remained elevated, cries were lower pitched, more rhythmic, with a rising‐falling pattern, and were mostly phonated, and body posturing returned to normal. Those faces that could be viewed also were returning to the at rest configuration. It was suggested that facial expression may be the most consistent across‐infant indicator of pain at this point in time.

A cross-sectional survey of pain and pharmacological analgesia in Canadian neonatal intensive care units.

OBJECTIVE To determine current practices for the use of analgesia term and preterm neonates cared for in Neonatal Intensive Care Units (NICUs). DESIGN One-week survey of medical charts of current patients. SETTING NICUs in Canada. PARTICIPANTS A total of 14 of 38 invited NICUs participated. These units were not different on number of beds, admissions per year, or university affiliation from the nonparticipating units. MAIN OUTCOME MEASURES Daily logs were kept of the frequency and type of procedures and analgesia administration for all ill neonates in each NICU during the study period. RESULTS The sample consisted of 239 patients. A total of 2,134 invasive procedures were performed. Medication was given specifically 18 times for 17 invasive procedures (0.8%). For another 129 invasive procedures, the patient was receiving analgesia for reasons other than the procedure. Sixteen patients had surgery during the survey period, and another 14 had surgery prior to but within 4 days of the survey. Fifty-one patients received anaesthesia or analgesia specifically related to surgery (39 times), procedures (35 times), or other reasons (34 times), a total of 108 courses. Opioids were the most frequently used medications and were given for all reasons, by continuous infusion, intermittent bolus, or sometimes both methods for the same patient. CONCLUSIONS Postoperative pain in neonates in Canadian NICUs appears to be consistently treated, primarily with opioid analgesics, but analgesia, opioid or nonopioid is rarely given for nonsurgical invasive procedures.

Developmental changes in pain expression in premature, full-term, two- and four-month-old infants

&NA; The purpose of this study was to examine the behavioural responses of infants to pain stimuli across different developmental ages. Eighty infants were included in this cross‐sectional design. Four subsamples of 20 infants each included: (1) premature infants between 32 and 34 weeks gestational age undergoing heel‐stick procedure; (2) full‐term infants receiving intramuscular vitamin K injection; (3) 2‐month‐old infants receiving subcutaneous injection for immunisation against DPT; (4) 4‐month‐old infants receiving subcutaneous injection for immunisation against DPT. Audio and video recordings were made for 15 sec from stimulus. Cry analysis was conducted on the first full expiratory cry by FFT with time and frequency measures. Facial action was coded using the Neonatal Facial Action Coding System (NFCS). Results from multivariate analysis showed that premature infants were different from older infants, that full‐term newborns were different from others, but that 2‐ and 4‐month‐olds were similar. The specific variables contributing to the significance were higher pitched cries and more horizontal mouth stretch in the premature group and more taut tongue in the full‐term newborns. The results imply that the premature infant has the basis for communicating pain via facial actions but that these are not well developed. The full‐term newborn is better equipped to interact with his caretakers and express his distress through specific facial actions. The cries of the premature infant, however, have more of the characteristics that are arousing to the listener which serve to alert the caregiver of the state of distress from pain.

Differential response to pain by very premature neonates

&NA; The ability of very low birth weight (VLBW) premature infants to respond differentially to real versus a sham heelstick conditions was examined in this crossover study. Using a multidimensional assessment of responses of premature infants (n = 48) between 26 and 31 weeks gestational age (GA) at the time of the study, it was found that they respond differentially to real versus sham heelstick both behaviourally and physiologically. The multivariate effect of condition (real/sham) was significant with maximum heart rate and upper facial action (lower facial action was not scored) contributing significantly to the main effect. GA had a main multivariate effect, with the younger infants responding less robustly. The variability outcome measures of heart rate standard deviation and range of transfontanelle intracranial pressure contributed significantly to the main effect of GA, but not to the effect of condition. Young VLBW premature infants are capable of a multidimensional differential response to pain. GA is an important factor to consider when assessing pain in premature infants.

Preoperative parental anxiety predicts behavioural and emotional responses to induction of anaesthesia in children

Parental presence at induction of anaesthesia is desirable if it makes the child happier and more cooperative. This study evaluated the emotional and behavioural responses of children to being accompanied by a parent at induction of anaesthesia in a paediatric day-care surgical centre. One hundred and thirty-four patients (aged 2–10 yr, ASA physical status I or II) were divided into two groups by day of surgery, to have a parent present at induction of anaesthesia (treatment group), or to be unaccompanied (control group). Before, and at one week after surgery, the child’s fears and behaviour were scored by the Hospital Fears Inventory (HFI) and Behavioural Questionnaire (BQ), and parental anxiety by the Parents’ Questionnaire (PQ) before and at one week after surgery. The Global Mood Scale (GMS) was used to assess the child’s behaviour and the Visual Analogue Scale (VAS) to assess the parent’s anxiety on arrival for surgery and at induction of anaesthesia. All patients and parents were disturbed by the experience, but to the same degree in the treatment and control groups. Subgroups of “ calm ” and “ anxious ” parents were identified by a median split of their preoperative VAS scores. Children in the“ calm-treatment,” “ calm-control ” and“ anxious-control ” subgroups were similarly upset at induction. Children in the“ anxious-treatment ” subgroup were the most disturbed at induction, and significantly more than those in the“ anxious-control” subgroup. Preoperative parental anxiety levels also correlated with the child’s fears and behaviour one week after surgery. Therefore, parental anxiety should be assessed preoperatively to allow“calm” parents to be present at induction if they wish, and“anxious” parents to be excluded and receive counselling and support.RésuméLa présence des parents au moment de I’induction de I’anes-thesie est désirable si elle rend I’enfant plus heureux et plus coopératif. Cette étude a évalué les réponses émotionnelles et le comportement des enfants accompagnés de leurs parents lors de I’induction de I’anesthésie dans un centre de chirurgie périatrique externe. Cent trente-quatre patients âgés de 2–10 ans, ASA I ou II) ont été divisés en deux groupes, le groupe traitement fut accompagné alors que pour le groupe «contrôle», aucun parent n’accompagnait l’enfant. Avant et aprés une semaine de la chirurgie, les craintes de l’enfant et son comportement furent évalués par les tests de « Hospital Fears Inventory » (HFI) et le « Behavioural Questionnaire » (BQ) et l’anxiété des parents fut évaluée par le questionnaire des parents (PQ). Le test du « Global Mood Scale » (GMS) a ete utilise afm d’évaluer le comportement de l’enfant et le test du « Visual Analogue Scale » (VAS) fut utilisé afin d’évaluer l’anxiété des parents à l’arrivée de la chirurgie et à l’induction de l’anesthésie. Tous les patients et les parents étaient perturbés par l’expérience, mais au même degré entre le groupe « traitement » et le groupe « controle ». Des sous-groupes de parents « calmes » et « anxieux » ont ete identifiés. Les enfants des sous-groupes « calmes-traitement » et « calmes-contrôle » et « anxieux-contrôle » etaient perturbés d’une façon similaire lors de l’induction. Les enfants du groupe « anxieux-traitement » etaient les plus perturbés lors de l’induction et significativement plus que le sous-groupe « anxieux-contrôle ». L’état d’anxiété préopératoire des parents était aussi relié aux craintes de l’enfant et à son comportement une semaine après la chirurgie. Ainsi, l’anxiété parentérale doit être évaluée dans la période préopératoire afin de calmer les parents présents à l’induction s’ils le désirent et les parents anxieux doivent être exclus et doivent recevoir support et conseil.

Factors that influence the behavioral pain responses of premature infants

&NA; The responses of preterm neonates to acute tissue‐damaging stimuli have been described. However, factors which influence these responses have received little attention. In this study, we observed 124 premature infants before, during and after a routine heel lance and determined how two contextual variables (severity of illness and behavioral state) influenced their behavioral responses. Significant changes in facial actions occurred between baseline and the most invasive phase of the heel lance procedure, stick. The fundamental frequency, harmonic structure and peak spectral energy of the infants cry were also significantly increased during the stick phase. Behavioral state was found to influence the facial action variables and severity of illness modified the acoustic cry variables. Accurate identification of pain in premature infants requires consideration of factors that influence their response.

Kangaroo mother care diminishes pain from heel lance in very preterm neonates: a crossover trial.

BackgroundSkin-to-skin contact, or kangaroo mother care (KMC) has been shown to be efficacious in diminishing pain response to heel lance in full term and moderately preterm neonates. The purpose of this study was to determine if KMC would also be efficacious in very preterm neonates.MethodsPreterm neonates (n = 61) between 28 0/7 and 31 6/7 weeks gestational age in three Level III NICUs in Canada comprised the sample. A single-blind randomized crossover design was employed. In the experimental condition, the infant was held in KMC for 15 minutes prior to and throughout heel lance procedure. In the control condition, the infant was in prone position swaddled in a blanket in the incubator. The primary outcome was the Premature Infant Pain Profile (PIPP), which is comprised of three facial actions, maximum heart rate, minimum oxygen saturation levels from baseline in 30-second blocks from heel lance. The secondary outcome was time to recover, defined as heart rate return to baseline. Continuous video, heart rate and oxygen saturation monitoring were recorded with event markers during the procedure and were subsequently analyzed. Repeated measures analysis-of-variance was employed to generate results.ResultsPIPP scores at 90 seconds post lance were significantly lower in the KMC condition (8.871 (95%CI 7.852–9.889) versus 10.677 (95%CI 9.563–11.792) p < .001) and non-significant mean differences ranging from 1.2 to1.8. favoring KMC condition at 30, 60 and 120 seconds. Time to recovery was significantly shorter, by a minute(123 seconds (95%CI 103–142) versus 193 seconds (95%CI 158–227). Facial actions were highly significantly lower across all points in time reaching a two-fold difference by 120 seconds post-lance and heart rate was significantly lower across the first 90 seconds in the KMC condition.ConclusionVery preterm neonates appear to have endogenous mechanisms elicited through skin-to-skin maternal contact that decrease pain response, but not as powerfully as in older preterm neonates. The shorter recovery time in KMC is clinically important in helping maintain homeostasis.Trial Registration(Current Controlled Trials) ISRCTN63551708