title: Contextual factors associated with pain response of preterm infants to heel-stick procedures.
abstract: BACKGROUND
  Evidence indicates that medical and demographic contextual factors (cFs) impact pain responses in preterm neonates, but the existing evidence is very heterogeneous.
  
  
  OBJECTIVE
  To explore the effect of cFs on pain responses to heel-stick procedures of preterm infants.
  
  
  METHODS
  This study was a secondary analysis of data collected during a randomized controlled trial examining pain response to non-pharmacological interventions across repeated heel sticks. Five heel sticks across the first 14 days of life were videotaped. Pain response was rated with the Bernese Pain Scale for Neonates (BPSN) by four raters blinded to the heel-stick phases (baseline, heel stick, recovery). Demographic and medical cFs were extracted from medical charts. Mixed single and multiple regression analyses were performed controlling for the intervention group, site and heel-stick phase.
  
  
  RESULTS
  Apgar scores at 1 min were negatively associated with behavioural (p = 0.002) BPSN scores, while Apgar scores at 5 min after birth were positively associated with behavioural (p = 0.006) scores. Accumulated number of painful procedures (p = 0.002) and gender (p = 0.02) were positively associated with physiological scores while continuous positive airway pressure CPAP (p = 0.009) and mechanical ventilation (p = 0.005) were negatively associated.
  
  
  CONCLUSIONS
  Higher exposure to painful procedures, male infants and having CPAP or mechanical ventilation were cFs associated with physiological response. The only variables significantly associated with behavioural BPSN scores were Apgar scores but these relationships were inconsistent.
authors.affiliation: Institute of Nursing Science, University of Basel, Basel, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Sellam
authors.forename: S
authors.initials: S
authors.lastname: Engberg
authors.forename: K
authors.initials: K
authors.lastname: Denhaerynck
authors.forename: K D
authors.initials: KD
authors.lastname: Craig
authors.forename: E L
authors.initials: EL
authors.lastname: Cignacco
mesh_terms: D000700:Analgesics / Q000627:therapeutic use; D001034:Apgar Score; D001800:Blood Specimen Collection / Q000009:adverse effects*; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects; D005260:Female; D005865:Gestational Age; D006365:Heel; D006801:Humans; D007223:Infant; D018730:Infant Behavior; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D010146:Pain / Q000209:etiology*; D010147:Pain Measurement; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012121:Respiration, Artificial / Q000009:adverse effects; D012727:Sex Characteristics
chemical_list: D000700:Analgesics