Neonatal pain assessment scales: review of the literature.

Introduction: The measurement of pain is the fundamental prerequisite for its proper management. Since newborns are unable to communicate verbally, neonatal algometric scales have been developed. However, no gold standard has been identified yet.
Objective: To identify and classify the most suitable and effective scales for different kinds of pain for term and preterm newborns in different clinical settings.
Method: The review was carried out between December 2019 and November 2020 by consulting the PubMed and CINAHL Database, combining Mesh terms and free text with appropriate inclusion and exclusion filters. The references reported in the articles found in the first part of the research were also analyzed, in order to identify further relevant studies.
Results: :Out of 2442 papers initially identified, we included 45 articles, describing 50 pain assessment scales (34 for acute pain, 12 for procedural pain, 24 for prolonged/chronic pain and 19 for pain after surgery). Scales with higher evidence are N-PASS, NFCS, BIIP and PIPP for acute and procedural pain, N-PASS, ALPS-Neo, EDIN and EDIN6 for prolonged/chronic pain, and PIPP, CRIES and COMFORT for pain after surgery.
Discussion: There is no unanimously accepted gold standard scale for neonatal pain. However, some are more suitable and effective: PIPP, NFCS, N-PASS and BIIP for acute pain; N-PASS, ALPS-Neo and EDIN/EDIN6 for chronic and prolonged pain; PIPP, CRIES and COMFORT for postoperative pain. Among all, N-PASS scale is the most complete and fits to different settings.