Related Experiment Video
Updated: May 16, 2026
A Preterm Rat Model for Pain Studies
Published on: February 9, 2024
Contextual factors associated with pain response of preterm infants to heel-stick procedures
G Sellam1, S Engberg, K Denhaerynck
1Institute of Nursing Science, University of Basel, Basel, Switzerland.
Insights
Contextual factors like accumulated painful procedures, male gender, and respiratory support (CPAP, mechanical ventilation) significantly influenced preterm neonates
Area of Science:
- Neonatal care
- Pain management in neonates
- Pediatric research
Background:
- Medical and demographic factors (cFs) influence pain responses in preterm infants.
- Existing evidence on these factors is highly varied.
- Understanding these influences is crucial for neonatal pain management.
Purpose of the Study:
- To investigate the impact of contextual factors on preterm infants' pain responses during heel-stick procedures.
- To analyze demographic and medical variables affecting pain perception.
- To provide insights into neonatal pain assessment and intervention.
Main Methods:
- Secondary analysis of a randomized controlled trial on non-pharmacological interventions.
- Videotaped heel-stick procedures in the first 14 days of life.
- Pain assessment using the Bernese Pain Scale for Neonates (BPSN) by blinded raters.
- Statistical analysis using mixed regression models controlling for covariates.
Main Results:
- Higher accumulated painful procedures and male gender correlated with increased physiological pain scores.
- Continuous positive airway pressure (CPAP) and mechanical ventilation were associated with decreased physiological pain.
- Apgar scores showed inconsistent associations with behavioral pain scores.
Conclusions:
- Increased procedural pain exposure, male sex, and respiratory support (CPAP, mechanical ventilation) are key contextual factors affecting physiological pain responses in preterm neonates.
- Behavioral pain responses were inconsistently linked to Apgar scores.
- Findings highlight the complexity of pain expression in preterm infants.
Background:
Evidence indicates that medical and demographic contextual factors (cFs) impact pain responses in preterm neonates, but the existing evidence is very heterogeneous.
Aim:
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.
Conclusion:
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.
