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.

Feeding and carrying have been interventions used by caregivers throughout history in relieving distress in infants. Recent studies on the food substance sucrose have elucidated the comforting effect of the taste component of feeding while studies of rocking have examined the comforting effect of the vestibular component of carrying. The purpose of this study was to determine the effectiveness of sucrose and simulated rocking alone and in combination on diminishing pain response in preterm neonates undergoing routine heelstick procedure in the neonatal intensive care unit (NICU). Preterm infants (n = 85) between 25-34 weeks post-conceptual age (PCA) and 2-10 days postnatal age (PNA) were randomly assigned to one of four conditions for routine heelstick procedure. The conditions were (1) sucrose alone: 0.05 ml of 24% sucrose was placed on the anterior surface of the tongue just prior to the lancing of the heel; (2) simulated rocking alone: 15 min prior to and during the heelstick procedure, the infant was swaddled and put on an oscillating mattress; (3) combination of sucrose and simulated rocking; and (4) placebo: 0.05 ml sterile water administered just prior to heelstick. Physiological (heart rate) and behavioural (facial actions) responses from baseline across 90 s following heelstick were scored second-to-second. Facial actions were analysed with repeated measures MANCOVA and heart rate with repeated measures ANCOVA. Behavioural state and gestational age were covariates. The groups that received sucrose alone or in combination with simulated rocking showed less facial actions indicative of pain than the rocking alone or control group. The addition of rocking to the sucrose condition tended to further blunt the facial expression of pain, but this enhancement did not reach a significant level. Heart rate was not decreased by any intervention compared to the control condition. Although the simulated rocking did promote quiet sleep, which has been reported in earlier studies to blunt pain response, there was no difference between simulated rocking and control groups in either facial expressions indicative of pain or heart rate. The implication of these results is that sucrose, but not simulated rocking may be a means of diminishing pain from minor procedures in preterm infants. Further research is needed on the use of sucrose for more than one procedure as well as examining the contact component of natural rocking, as opposed to simulated rocking.

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).

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 infant's 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.

SUMMARY Twenty‐eight preterm infants of 28 weeks gestational age were observed four times over eight weeks in order to determine changes in their pain response. Both routine and sham heelstick procedures were used. Physiological (heart rate and oxygen saturations) and behavioural parameters (three upper facial actions) were used as outcomes. The responses to real heelstick were significantly greater than to sham heelstick for heart rate and all facial actions except one at 28 weeks gestational age, but not for oxygen saturation. The magnitude of response to both real and sham heelstick increased over time. Thus, the older the infant, the more robust and recognisable the response. Since even the youngest infants showed a differential response to pain, professionals caring for such infants need to be able to recognize their more subtle pain responses. RÉSUMÉ Modifications développementales en réponse à hi pitúire chez le prématuré: une étude prospective de cohorte Vingt‐huit prématurés de 28 semaines d'âge de gestation furent observés quatre fois sur une période de huit semaines dans le but de déterminer les modifications dans leurs réponses à la douleur. Les procédures de piqûrcs de talon et de fausses piqûres de talon furent utilisées. Des paramètres physiologiqucs (rythme cardiaque et saturation d'oxygène) et comportementaux furent utilisés pour apprécier les effets. Les réponses aux vraies piqûres furent significativement plus fortes que pour les fausses piqûres en ce qui concernait le rythme cardiaque et toutes les expressions faciales sauf dans un cas à 28 semaines d'âge de gestation, mais non pour la saturation en oxygène. L'amplitude de la réponse pour les fausses et les vraies piqûrcs augmentait avec le temps. Plus le nourrisson était âgé. plus la réponse était forte et identifiable. Puisque même les nourrissons les plus jeunes présentent une réponse différenciée à la douleur, les professionnels de soins de ces enfants devraicnt êire capables de reconnaître leurs plus subtiles réponses à la douleur. ZUSAMMENFASSUNG Veränderungen der Reaklion von Frühgeborenen aufden Fersenslich Acht und zwanzig Frühgeborene mit einem Gestationsalter von 28 Wochen wurden in acht Wochen viermal kontrolliert, um Veränderungen ihrer Schmerzreaktion festzustellen. Es wurden reguläre sowie vorgetäuschte Fcrsenstichc durchgeführt. Physiologische (Herzfrequenz und 02‐Sättigung) und Verhaltensparameter (drei Gesichtsreaktionen) wurden als Ergebnis ausgewertet. Außer bei einem Kind mit einem Gestationsalter von 28 Wochen veränderten sich Herzfrequenz und alle Gesichtsreaktionen auf den regulären Fersenstich sigifikant stärker als auf den vorgetäuschten, was bei der 02‐Sättigung nicht zu beobachten war. Die Reaktion auf den regulären wie auf den vorgetäuschten Fersenstich nahm mit der Zeit zu. Je älter das Kind war, desto eindeutiger und erkennbarer war die Reaktion. Da selbst die jüngsten Kinder eine differenzierte Schmerzreaktion zeigten, sollte das Fachpersonal, das diese Kinder betreut, in der Lage sein, ihre eher subtilen Schmer...