Related Experiment Video
Updated: Dec 8, 2025
A Preterm Rat Model for Pain Studies
Published on: February 9, 2024
The newborn infant parasympathetic evaluation index for acute procedural pain assessment in preterm infants
Julie Gendras1,2, Pauline Lavenant1,2, Iona Sicard-Cras1,2
1Pôle de Femme, de la Mère et de l'Enfant, Centre Hospitalier Régional Universitaire, Brest, France.
Insights
The newborn infant parasympathetic evaluation (NIPE) index did not correlate with the Premature Infant Pain Profile Revised (PIPP-R) scale for assessing procedural pain in preterm infants. However, the NIPE index and skin conductance responses may help rule out severe pain.
Area of Science:
- Neonatal care
- Pain assessment
- Physiological monitoring
Background:
- Accurate pain assessment in preterm infants is crucial for mitigating adverse outcomes.
- Existing pain assessment tools for neonates have limitations.
- The newborn infant parasympathetic evaluation (NIPE) index is a novel physiological measure for pain.
Purpose of the Study:
- To evaluate the newborn infant parasympathetic evaluation (NIPE) index's ability to detect acute procedural pain in preterm infants.
- To compare the NIPE index with the Premature Infant Pain Profile Revised (PIPP-R) scale and skin conductance responses (SCR).
Main Methods:
- Prospective observation of painful and stressful interventions in preterm infants (25 0/7 to 35 6/7 weeks gestation).
- Pain assessment using the PIPP-R scale, NIPE index, and SCR.
- Correlation and sensitivity/specificity analyses between NIPE, PIPP-R, and SCR.
Main Results:
- No significant correlation was found between the NIPE index and the PIPP-R scale.
- PIPP-R and SCR were positively correlated, particularly for skin-breaking procedures (r=0.82).
- The NIPE index and SCR demonstrated high sensitivity and negative predictive values for identifying PIPP-R scores >10, especially during skin-breaking procedures.
Conclusions:
- The NIPE index did not show significant correlation with the PIPP-R scale for assessing routine procedural pain in preterm infants.
- The NIPE index, alongside SCR, may assist in excluding severe pain in this population.
- Multidimensional pain assessment combining physiological and behavioral measures is recommended in clinical practice.
Background:
Accurate assessments of pain in hospitalized preterm infants present a major challenge in improving the short- and long-term consequences associated with painful experiences. We evaluated the ability of the newborn infant parasympathetic evaluation (NIPE) index to detect acute procedural pain in preterm infants.
Methods:
Different painful and stressful interventions were prospectively observed in preterm infants born at 25 + 0 to 35 + 6 weeks gestation. Pain responses were measured using the composite Premature Infant Pain Profile Revised (PIPP-R) scale, the NIPE index, and skin conductance responses (SCR). Outcome measures were correlations between the NIPE index, the PIPP-R score, and the SCR. Sensitivity/specificity analyses tested the accuracy of the NIPE index and SCR.
Results:
Two hundred and fifty-four procedures were recorded in 90 preterm infants. No significant correlation was found between PIPP-R and the NIPE index. PIPP-R and SCR were positively correlated (r = 0.27, P < 0.001), with stronger correlations for painful procedures (r = 0.68, P < 0.001) and especially for skin-breaking procedures (r = 0.82, P < 0.001). The NIPE index and SCR had high sensitivity and high negative predictive values to predict PIPP-R > 10, especially for skin-breaking painful procedures.
Conclusions:
We found no significant correlation between the NIPE index and PIPP-R during routine painful or stressful procedures in preterm infants.
Impact:
Exposure to repetitive pain can lead to neurodevelopmental sequelae. Behavior-based pain scales have limited clinical utility, especially for preterm infants. New devices for monitoring physiological responses to pain have not been validated sufficiently in preterm infants. This study found that the NIPE index was not significantly correlated to the validated PIPP-R scale during acute procedural pain. Secondary analysis of this study showed that NIPE index and SCRs may help to exclude severe pain in preterm infants. In clinical practice, measurements of physiological parameters should be combined with behavior-based scales for multidimensional pain assessments.
