Effect of Non-nutritive Sucking during Heel-stick Procedure in Pain Management of Term Infants in the Neonatal Intensive Care Unit: A Systematic Review and Meta-analysis

Background: This study aimed to evaluate the efficacy of non-nutritive sucking for analgesia in term infants undergoing heel-stick procedures. Methods: Randomized controlled trials and non-randomized studies based on the PICO framework were included in the study. Review articles, commentary, pilot, and non-English articles were excluded. Databases, such as PubMed/MEDLINE, Embase, Scopus, Web of Science, and Cochrane, were searched until January 31st, 2021, using the keywords “Pain management”, ‘Non-nutritive sucking”, and “Heel stick”. All studies were reviewed and retrieved by two authors independently using a standardized form according to the inclusion criteria, and any disagreements were examined by a third scholar. Quality assessment was evaluated by using the ROB-2 tool. Data were analyzed using Stata version 12.0 software, and a random-effects model was used for analysis. Results: A total of 5,629 articles were retrieved from all databases, and after the screening, finally, 6 relevant articles were included in the analysis. The tools used to control pain in infants in the articles included PIPP, NFCS, NIPS, and NPASS. The results showed that the pain scores were significantly lower in the NNS group compared to the control group (MD, -1.05; 95% CI, -1.53 to -0.57) and NNS had a significant effect on oxygen saturation (O2 Sat) increasing in newborns compared to the control group, but no significant reduction in the heart rate (HR) between two groups was observed. Conclusion: NNS effectively provides analgesia in full-term neonates undergoing heel-stick procedures; however, its effects on the long-term outcomes of infants are unclear. The results showed that NNS was effective in improving heel-stick pain in infants.