Evaluation of Pain Prevalence in Children Who Experienced Perinatal Hypoxia-Ischemia Events: Characteristics and Associations With Sociodemographic Factors

Introduction: Pain in children who suffer from hypoxia-ischemia (HI) events is still not widely studied. Hypoxia-ischemia is characterized by the momentary or permanent cessation of blood flow and, consequently, of oxygen supply, becoming the main cause of encephalopathy in children. Hyperalgesia was identified in animals undergoing prenatal hypoxia-ischemia by researchers from the Universidade do Estado do Rio de Janeiro (UERJ). Premature and asphyxiated newborns have been admitted to the neonatal intensive care unit (NICU) of Pedro Ernesto University Hospital (HUPE) in Brazil and are monitored by the Outpatient Follow-up of High-Risk Newborns Project (SARAR), but no pain assessment was performed. Objective: To assess pain in children born in high-risk situations, such as prematurity and perinatal asphyxia, with higher chances of perinatal HI, discharged from the NICU/HUPE, and followed by SARAR. Methodology: The study was approved by the HUPE Research Ethics Committee. The epidemiological, descriptive, cross-sectional study started in 2021 and finished in 2023, with the application of the pain assessment tool or instrument adapted from the Lübeck Pain-Screening Questionnaire to the caregivers and with the collection of growth and development data. The population consisted of asphyxiated infants born with a gestational age greater than 35 weeks and submitted to the Therapeutic Hypothermia protocol and premature infants discharged from the NICU between two (gestational age 1 (GA1)) and 12 years old. For most of them, pain prevalence was assessed according to its frequency and intensity, as were sociodemographic variables of the child and mother, neural alterations, and the Children's Developmental Scale (DENVER II). The percentage differences between the evaluated factors and the presence of pain were performed using Fisher's exact test and medians using the non-parametric Wilcoxon rank-sum test, both appropriate for the small sample of children. Significance levels of 10% were considered for trends and 5% for statistically significant differences. Results: Of the 86 children included in our search, 26 (30%) were born with a gestational age greater than 35 weeks and diagnosed with perinatal asphyxia (hereinafter referred to as the asphyxiation group), and 60 (70%) were premature. Pain was reported by 22 (25%) children, of whom 54.4% reported moderate or severe pain. The head and abdomen were the most reported sites (36%). Differences were observed in the percentage distribution of pain between asphyxiates and premature infants (11% vs. 32%; p-value 0.061 on the Fisher test) and between females and males (34% vs. 17%; p-value 0.085 on the Fisher test). Black and Brown children had higher median pain scale values than White children (p-value < 0.027, Wilcoxon rank sum test). Conclusion: There is a higher prevalence of pain in girls, in the head, in premature infants, and greater intensity among Black and Brown children. Therefore, knowing the pain profile can help improve their quality of life by offering treatments.