Factors associated with infant pain response following an immunization injection.

OBJECTIVES: Specific potential determinants of infant pain response were assessed in the context of a 4- or 6-month immunization injection. The distal influences of gender, gestational and current age, temperament, and early nociceptive stimuli were considered, as well as the proximal influences of parental and nurse coping-promoting statements within the treatment room. STUDY DESIGN: An observational study design was used. Pain responses in 93 infants receiving an immunization injection were videoed and coded using the Neonatal Facial Coding System (NFCS) and duration of crying was recorded. Parent and nurse vocalizations were coded using the Child-Adult Medical Procedure Interaction Scale-Revised. RESULTS: A multiple regression analysis evaluated the influence of the 5 distal and 2 proximal factors on NFCS scores, and found parental coping-promoting statements in the 30 s period before the injection to have the strongest effect on facial pain response (p<0.01). Parents made significantly more coping-promoting statements (p<0.05), and generally talked more (p<0.05), to female infants than male infants. CONCLUSIONS: The findings suggest that parental behavior in the treatment room has a key role in influencing how infants respond to painful procedures.

Pediatric procedural pain.

This article reviews the various settings in which infants, children, and adolescents experience pain during acute medical procedures and issues related to referral of children to pain management teams. In addition, self-report, reports by others, physiological monitoring, and direct observation methods of assessment of pain and related constructs are discussed and recommendations are provided. Pharmacological, other medical approaches, and empirically supported cognitive behavioral interventions are reviewed. Salient features of the interventions are discussed, and recommendations are made for necessary components of effective treatment interventions.

Effects of attentional direction, age, and coping style on cold-pressor pain in children.

This study assessed the relative efficacy of two imagery-based attentional strategies for modifying pain experience in children. Children aged 7-14 years (n = 120) were randomly assigned to one of three conditions: distraction, sensory-focussing or control (no imagery). The distraction condition prompted children to focus their attention externally; the sensory-focussing condition prompted the child to focus internally on physical sensations. Self-report measures of pain coping style preferences and imagery ability were completed. Children's pain tolerance and perceptions of pain intensity were assessed using a 10 degrees C cold-pressor task. Results showed pain intensity ratings after 1 min were lower for both intervention conditions than for the controls. Younger children (7-9 years) showed higher pain tolerance in the distraction condition than in the sensory-focussing condition, whereas both interventions were equally effective for older children (10-14 years). Among older children, coping style interacted with the intervention type: in the sensory-focussing condition, pain tolerance was negatively associated with self-reported distraction-based coping style, whereas in the distraction condition this association was positive. The results are interpreted with reference to current models of attention. The implications for use of attentional strategies in helping children to cope with clinical pain are discussed.

Guidelines for the cold pressor task as an experimental pain stimulus for use with children.

UNLABELLED: The cold pressor task (CPT) involves placing a hand or forearm in cold water, a stimulus that produces a slowly mounting pain of mild to moderate intensity and is terminated by voluntary withdrawal of the limb. The CPT has been used in many studies of pain, autonomic reactivity, and hormonal stress responses. Use of the CPT with children was first reported in 1937, and it has been used since then in at least 24 published studies including more than 1700 children without reported adverse effects. However, differences in water temperature, apparatus, and procedure might contribute to conflicting results. We offer suggested guidelines for the safe construction and operation of apparatus for the CPT and for consistent administration of the task and measurement. In particular, use of continuously circulating water at a temperature of 10 degrees C +/- 1 degrees C is recommended for the CPT with children and adolescents. Data on children's pain tolerance found in CPT studies in the authors' laboratories are provided. PERSPECTIVE: Differences in methodology might have contributed to conflicting results in published research using the CPT with children. These guidelines for apparatus and for administration of the CPT might be helpful to researchers planning such studies. Questions for research leading toward further methodologic refinement are identified.

Efficacy and safety of acetaminophen vs ibuprofen for treating children's pain or fever: a meta-analysis.

OBJECTIVE: To summarize studies testing the efficacy and safety of single-dose acetaminophen and ibuprofen for treating children's pain or fever. DATA SOURCES: Reports were gathered by searching computerized databases (from their inception through May 2002) and registries, relevant journals, and bibliographies of key articles. STUDY SELECTION: Seventeen blinded, randomized controlled trials with children (<18 years) receiving either drug to treat fever or moderate to severe pain. DATA EXTRACTION: Under a fixed-effects model, outcome measures for an initial single dose of ibuprofen vs acetaminophen were the risk ratio for achieving more than 50% of maximum pain relief, effect size for febrile temperature reduction, and risk ratio for minor and major harm. DATA SYNTHESIS: Ibuprofen (4-10 mg/kg) and acetaminophen (7-15 mg/kg) showed comparable efficacy (3 pain relief trials; 186 children). The risk ratio point estimates was 1.14 (95%confidence interval [CI], 0.82-1.58) at 2 hours after receiving the dose, and 1.11 (95% CI, 0.89-1.38) at 4 hours. Ibuprofen (5-10 mg/kg) reduced temperature more than acetaminophen (10-15 mg/kg) at 2, 4, and 6 hours after treatment (respective weighted-effect sizes: 0.19 [95% CI, 0.05-0.33], 0.31 [95% CI, 0.19-0.44], and 0.33 [95% CI, 0.19-0.47]) (9 fever trials; 1078 children). For ibuprofen 10 mg/kg (acetaminophen, 10-15 mg/kg), corresponding effect sizes were 0.34 (95% CI, 0.12-0.56), 0.81 (95% CI, 0.56-1.03), and 0.66 (95% CI, 0.44-0.87). There was no evidence the drugs differed from each other (or placebo) in incidence of minor or major harm (17 safety trials; 1820 children). CONCLUSIONS: In children, single doses of ibuprofen (4-10 mg/kg) and acetaminophen (7-15 mg/kg) have similar efficacy for relieving moderate to severe pain, and similar safety as analgesics or antipyretics. Ibuprofen (5-10 mg/kg) was a more effective antipyretic than acetaminophen (10-15 mg/kg) at 2, 4, and 6 hours posttreatment.

Cognitive-behavioural predictors of children's tolerance of laboratory-induced pain: implications for clinical assessment and future directions.

This study sought to investigate cognitive-behavioural predictors of children's tolerance for laboratory-induced cold-pressor pain. It was hypothesised that pain tolerance, as measured by immersion time, would be greater in children who were high in self-efficacy for pain, high in self-reported use of cognitive-coping strategies, and low in emotion-focused coping strategies such as catastrophising. Age and sex differences were also examined in post hoc analyses. Children between the ages of 7 and 14 years (N = 53) participated in the study. Offering partial support for the hypotheses, use of cognitive distraction was found to be associated with greater pain tolerance, while use of internalising/catastrophising was associated with lower pain tolerance. Older boys tended to have greater pain tolerance than younger boys, whereas younger and older girls had intermediate pain tolerance levels. Self-efficacy for pain, in general, was found to be positively correlated with age. The results support efforts to identify children who, because they have lower confidence or lower skills in coping with distress, may need extra support and preparation for painful procedures. Further research is needed to investigate these findings within a clinical pain context.