EDIN and N-PASS pain scale comparison in asphyxiated newborns treated with therapeutic hypothermia

Background Therapeutic hypothermia (TH) is the standard treatment for moderate to severe hypoxic–ischemic encephalopathy (HIE), yet pain assessment during TH remains challenging. This study compares two validated pain scales in asphyxiated newborns undergoing TH and receiving fentanyl analgesia. Methods Twenty term infants with HIE treated with TH were enrolled. Pain was assessed using EDIN and N-PASS, while sedation was monitored using the N-PASS sedation subscale. Results N-PASS pain and sedation scores significantly decreased by day 3, whereas EDIN scores showed no significant temporal change. Effective analgesia significantly increased over time, either when defined based on EDIN (OR 3.12, p = 0.002) and on N-PASS (OR 3.06, p = 0.007), while N-PASS sedation did not show a time-dependent association. No scale showed a significant association with fentanyl dosage. A moderate positive correlation was found between EDIN and N-PASS pain scores ( r = 0.409, p < 0.001). Sedation targets were achieved in only 40%–50% of assessments, with early undersedation and later oversedation observed. Conclusions EDIN and N-PASS pain scores demonstrate moderate concordance, but capture different dimensions of neonatal pain during TH. N-PASS appears more sensitive to temporal changes, likely due to its combined behavioral and physiological components, whereas EDIN may be affected by hypothermia-related behavioral suppression.