Biobehavioral pain responses in former extremely low birth weight infants at four months' corrected age

To compare biobehavioral responses to acute pain at 4 months' corrected age between former extremely low birth weight (ELBW) infants and term-born controls.

Long-term effects of pain in infants

Pain and stress have been shown to induce significant physiological and behavioral reactions in newborn infants, even in those born prematurely. Infants who are born prematurely or seriously ill are commonly exposed to multiple painful and stressful events as part of their prolonged hospitalizations and required medical procedures. There is now evidence that these early events not only induce acute changes, but that permanent structural and functional changes may also result. This article reviews the growing body of evidence of likely long-term effects of early pain and stress on the human infant. It is hoped that a better understanding of this literature will promote more responsive and sensitive management of infants and young children during their encounters with the medical community and will ultimately facilitate the healthy growth and development of all children.

The developmental character of cardiac autonomic responses to an acute noxious event in 4- and 8-month-old healthy infants

Heart rate (HR) has been widely studied as a measure of an individual's response to painful stimuli. It remains unclear whether changes in mean HR or the variability of HR are specifically related to the noxious stimulus (i.e. pain). Neither is it well understood how such changes reflect underlying neurologic control mechanisms that produce these responses, or how these mechanisms change during the first year of life. To study the changes in cardiac autonomic modulation that occur with acute pain and with age during early infancy, the relationship between respiratory activity and short-term variations of HR (i.e. respiratory sinus arrhythmia) was quantified in a longitudinal study of term born healthy infants who underwent a finger lance blood collection at 4 months of age (n = 24) and again at 8 months of age (n = 20). Quantitative respiratory activity and HR were obtained during baseline, lance, and recovery periods. Time and frequency domain analyses from 2.2-min epochs of data yielded mean values, spectral measures of low (0.04-0.15 Hz) and high (0.15-0.80 Hz) frequency power (LF and HF), and the LF/HF ratio. To determine sympathetic and parasympathetic cardiac activity, the transfer relation between respiration and HR was used. At both 4 and 8 months, mean HR increased significantly with the noxious event (p > 0.01). There were age-related differences in the pattern of LF, HF, and LF/HF ratio changes. Although these parameters all decreased (p > 0.01) at 4 months, LF and LF/HF increased at 8 months and at 8 months HF remained stable in response to the noxious stimulus. Transfer gain changes with the lance demonstrated a change from predominant vagal baseline to a sympathetic condition at both ages. The primary finding of this study is that a response to an acute noxious stimulus appears to produce an increase in respiratory-related sympathetic HR control and a significant decrease in respiratory-related parasympathetic control at both 4 and 8 months. Furthermore, with increasing age, the sympathetic and parasympathetic changes appear to be less intense, but more sustained.

Judging pain in infants:behavioural, contextual, and developmental determinants

Caretakers intuitively use various sources of evidence when judging infant pain, but the relative importance of salient cues has received little attention. This investigation examined the predictive significance for judgements of painful discomfort in preterm and full-term neonates of behavioural (facial activity and body movement), contextual (invasiveness of the procedure), and developmental (gestational age) information. Judges viewed videotapes showing infants varying in the foregoing characteristics undergoing heel incisions for routine blood sampling purposes. Findings indicated all but the contextual information contributed uniquely to judgements of pain, with facial activity accounting for the most unique variance (35%), followed by bodily activity and gestational age, each accounting for 3% and 1% of the judgmental variance, respectively. Generally, 71% of the variance in ratings of pain could be predicted using facial activity alone, compared to 30% of the variance using bodily activity alone, 19% by relying on context alone, and 8% by referring to gestational age alone. Noteworthy was the tendency to judge early preterm infants to be experiencing less pain even though they were subjected to the same invasive procedure as the older infants. This finding also runs counter to evidence from developmental neurobiology which indicates that preterm newborns may be hypersensitive to invasive procedures.

The expression of pain in infants and toddlers:developmental changes in facial action

Age-related changes in the facial expression of pain during the first 18 months of life have important implications for our understanding of pain and pain assessment. We examined facial reactions video recorded during routine immunization injections in 75 infants stratified into 2-, 4-, 6-, 12-, and 18-month age groups. Two facial coding systems differing in the amount of detail extracted were applied to the records. In addition, parents completed a brief questionnaire that assessed child temperament and provided background information. Parents' efforts to soothe the children also were described. While there were consistencies in facial displays over the age groups, there also were differences on both measures of facial activity, indicating systematic variation in the nature and severity of distress. The least pain was expressed by the 4-month age group. Temperament was not related to the degree of pain expressed. Systematic variations in parental soothing behaviour indicated accommodation to the age of the child. Reasons for the differing patterns of facial activity are examined, with attention paid to the development of inhibitory mechanisms and the role of negative emotions such as anger and anxiety.

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

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; and (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.

A controlled trial of early interventions to promote maternal adjustment and development in infants born with severe congenital heart disease

Background: Congenital heart disease can have a negative impact on both infant development and maternal adjustment. This study considered the impact of a new programme of early psychosocial interventions on such outcomes, following the birth of a child with severe congenital heart disease.
Methods: Seventy infants and their mothers were assigned to an intervention or control group based on order of presentation to the unit. Interventions aimed at bolstering mother–infant transactions, through psychoeducation, parent skills training and narrative therapy techniques were implemented.
Results: Clinically and statistically signi?cant gains were observed at 6-month follow-up on the mental (but not the psychomotor) scale of the Bayleys-II. Positive gains were also manifested on feeding practices, maternal anxiety, worry and appraisal of their situation.
Conclusions: A programme of generalizable psychosocial interventions is shown to have a positive impact on the infant with severe congenital heart disease and the mother.

Predictors of psychological functioning in mothers and fathers of infants born with severe congenital heart disease

This study examined mental health and coping styles in both mothers and fathers of infants born with a severe congenital heart defect. Factors associated with mental health outcomes were elucidated. Parents of 70 infants, recently born with a severe congenital heart defect, completed questionnaires which examined psychological functioning and coping strategies. Disease, surgical and psychosocial factors were examined for their significance in predicting psychological functioning. Findings indicated elevated levels of clinically significant psychological distress in mothers, compared to fathers, and differences between parents in coping styles. Regression analyses suggested that the extent of distress in both parents was not primarily predicted by illness or demographic factors. Rather, certain coping styles, knowledge, subjective worry and family functioning emerged as significant predictive variables. Implications for early intervention are discussed.

Aqueous shunts for intractable glaucoma in infants

Purpose. To evaluate the utility of aqueous shunt implants in the treatment of infantile glaucoma refractory to conventional therapy. Methods. We retrospectively studied 10 eyes of 7 infants (mean age 12.4 ± 12.7 months) with uncontrolled glaucoma, who were managed with aqueous shunt implants. Adjunctive antimetabolites were used in 4 eyes. Results. The mean intraocular pressure before surgery was 32.2 ± 5.6 mmHg and the final was 17.7 ± 4.9 mmHg at a mean follow up of 11.5 ± 14.9 months. Two eyes (20%) required further glaucoma surgery. No major complications directly related to the aqueous shunt surgery were observed. Conclusions. Aqueous shunts can be effective in the management of intractable glaucoma in infants.

Aqueous shunts for intractable glaucoma in infants

BACKGROUND AND OBJECTIVE: To evaluate the long-term outcome of aqueous shunts in the treatment of infantile glaucoma refractory to conventional treatment. PATIENTS AND METHODS: The records of all patients up to 3 years of age managed with aqueous shunts for uncontrolled glaucoma between November 1990 and November 1996 were retrospectively reviewed. Ten eyes of 6 patients were included in the study. RESULTS: The mean preoperative intraocular pressure (IOP) was 29.75 ± 4.15 (mm Hg; SD), with none of the eyes on antiglaucoma medication. Postoperatively, the mean IOP was 18.25 ± 5.34 (mm Hg; SD) at a mean follow up of 50 ± 25.6 (SD) months with 7 eyes on topical antiglaucoma medication. At the final follow up, 6 eyes were considered successfully controlled without reintervention, 2 more were controlled after shunt revision, and 2 were considered failures. CONCLUSIONS: Aqueous shunts were relatively effective in this series of infants with recalcitrant glaucoma.

Known risk factors for violence predict 12-month-old infants' aggressiveness with peers

This study tested the hypothesis that 12-month-old infants' use of force against peers is associated with known risk factors for violence. We conducted a prospective longitudinal study, which included laboratory observations of firstborn British infants (N = 271) during simulated birthday parties. No gender differences in aggressiveness were observed. The infants' observed aggressiveness was significantly correlated with mothers' mood disorder during pregnancy and with mothers' history of conduct problems. Infants' observed aggressiveness was correlated with parents' ratings of infants' anger and aggression, which were also predicted by mothers' mood disorder and history of conduct problems. Our findings indicate that infants at risk for serious aggression can already be identified when the motor ability to use physical force first enters the human repertoire.

Prenatal and postnatal inflammation in relation to cortisol levels in preterm infants at 18 months corrected age

Objective

To examine whether early inflammation is related to cortisol levels at 18 months corrected age (CA) in children born very preterm.

Study Design

Infants born ≤ 32 weeks gestational age were recruited in the NICU, and placental histopathology, MRI, and chart review were obtained. At 18 months CA developmental assessment and collection of 3 salivary cortisol samples were carried out. Generalized least squares was used to analyze data from 85 infants providing 222 cortisol samples.

Results

Infants exposed to chorioamnionitis with funisitis had a significantly different pattern of cortisol across the samples compared to infants with chorioamnionitis alone or no prenatal inflammation (F[4,139] = 7.3996, P <.0001). Postnatal infections, necrotizing enterocolitis and chronic lung disease were not significantly associated with the cortisol pattern at 18 months CA.

Conclusion

In children born very preterm, prenatal inflammatory stress may contribute to altered programming of the HPA axis.

Keywords: preterm, chorioamnionitis, funisitis, premature infants, hypothalamic-pituitary-adrenal axis, infection, cortisol, stress

Neonatal intensive care and late preterm infants:Health and family functioning at three years

Background: Late preterm infants (LPIs), born at 34 + 0 to 36 + 6 weeks of gestation contribute a significant proportion of all neonatal intensive care (NIC) admissions and are regarded as being at risk of adverse outcomes compared to term-born infants.

Aim: To explore the health outcomes and family functioning of LPIs who required neonatal intensive care, at three years of age.

Study design and subjects: This cohort study included 225 children born late preterm, between 1 January and 31 December 2006 in Northern Ireland. Children admitted for NIC (study group, n = 103) were compared with children who did not require NIC or who required special care only for up to three days (comparison group, n = 122).

Outcome measures
Health outcomes were measured using the Health Status Questionnaire, health service usage by parent report and family functioning using the PedsQL™ Family Impact Module.

Results: LPIs who required NIC revealed similar health outcomes at three years in comparison to those who did not. Despite this, more parents of LPIs who required NIC reported visiting their GP and medical specialists during their child's third year of life. Differences in family functioning were also observed with mothers of LPIs who required NIC reporting, significantly lower levels of social and physical functioning, increased difficulties with communication and increased levels of worry.

Conclusions: LPIs were observed to have similar health outcomes at three years of age regardless of NIC requirement. The increase in GP and medical specialist visits and family functioning difficulties observed among those infants who required NIC merits further investigation.

Abbreviations: LPI, late preterm infant; NIC, neonatal intensive care; HSQ, Health Status Questionnaire; GP, general practitioner