This study provides reliability measures between two scales used to assess pain in preterm infants during a painful procedure. We evaluated the Correlation between the NIPS and PIPP-R scales, the internal consistency of each scale, and the reliability between the two evaluators in assessing pain during the aspiration procedure in premature newborns. Both scales were sensitive in identifying pain. In evaluating pain in the three aspiration procedures, we note that the pain was more evident in the vacuum, not intervention. We could see a difference in pain evaluation in the three procedures through the two scales and that the pain is less when used methods no pharmacological pain relief.
Identifying reliable instruments will help the care team better control pain, improving the quality of care for vulnerable newborns. In addition, our study corroborates the study by Bueno et al. (20) which initially validated the Brazilian version of the PIPP- R, which showed that the scores on this scale were responsive both to painful stimuli and to different pain relief strategies.
In the study by Peng et al. using the PIPP to assess pain in 109 newborn premature during the procedure of puncture of the heel, observed one risk lowest of pain moderate and severe in infants who received combinations of suction, milk breast, and bending facilitated when compared to babies who received routine care (22). In this study, despite a decrease in total score range PIPP-R, the pain was rated with moderate in three procedures.
Reliability and internal consistency (14), in the observational study by Xie et al. (14), four assessed scales (Neonatal Facial Coding System (NFCS), Doulleur Aiguedu Nouveau-Née (DAN), NIPS, PIPP ) for validity in assessing pain during blood collection from the heel of 111 preterm infants observed that all four rankings were high. Our results showed high reliability and internal consistency on the NIPS scale and moderate reliability and inner surface on the PIPP-R scale. It has found no study to evaluate scales of pain neonatal during the procedure of aspiration.
Huang et al. (23), when evaluating 90 premature newborns and terms of invasive mechanical ventilation, obtained results similar to those of the present study, in which the Cronbach's alpha of the three scales was an acceptable score. Thus, it provided evidence for good reliability between the Neonatal-Pain, Agitation and Sedation Sclae (N-PASS), NAPAS, and PIPP-R scales for neonates on mechanical ventilation. However, the internal consistency of the N-PASS scales and NAPAS was higher than PIPP-R. The reason to explain with slight differences in the numbers and graduation of behavioral or physiological indicators and the contextual factor, Gestational Age, affects the internal consistency of the PIPP-R (23).
In Brown et al. (20) study for adaptation and scale validation PIPP-R in Brazil, three nurses evaluated two sets of data studies randomized to assess pain in newborns using the PIPP scale. In the first study, 47 neonates analyzed with a mean gestational age of 35.4 weeks underwent heel puncture. In the second study, 84 babies with an age mean of 36.7 weeks underwent catheter exchange. The nurses indicated it was necessary to train further on the score of PIPP-R and the importance of establishing a behavioral state base before handling the baby, often a step forgotten by them (20). This finding was similar to other studies of psychometric properties since a more significant internal without any demonstrated consistency of the PIPP-R, especially compared to the NIPS scale.
The professionals couldn't facilitate the use of the assessment tool pain by professionals with the original version of the PIPP scale, recently been revised ( PIPP-R). Despite the maintenance of the indicators, the modified scoring method, in hands saturation of oxygen, demonstrated facial activity facial ( arching the brow, eyes tight and nasolabial folds), behavioral state baseline, and age pregnancy. Studies have shown the validity of the construct, convergent validity, and high Correlation between the scores of PIPP- range R and PIPP pain relief for different strategies as, for example, glucose, glucose associated with the suction, and breastmilk, as well as for other procedures, as puncture heel and vein in babies to term and preterm infants (20, 24).
Before the painful event of high based scores on baseline characteristics, the changing of behavioral states and GA scores minimized the effects. n PIPP-R, GA and behavioral. This study brought High inter-rater reliability for NIPS and PIPP-R with ICCs greater than 0.90 (21). The findings corroborate the results found in the survey by Motta et al. (18), which performed the cross-cultural adaptation of the NIPS in Brazil with an assessment of 60 NBs by six nurses and showed excellent reliability among observers. In addition, in the study by Gibbins et al. (24), there was a high agreement among evaluators using the PIPP-R scale.
In a prospective crossover study, one hundred ninety-five bedside nurses evaluated 202 hospitalized infants divided into three gestational age groups (26-31, 32-36, and >37 weeks) in three different NICUs during painful procedures. The high degree of agreement between PIPP-R expert evaluators and nurses in the assessment of during painful (0.92) and non-painful (0.87) procedures suggests that the instrument is appropriate, reliable, and consistent with all babies over 26 weeks gestation in the NICU during the evaluation in time real (24).
The NIPS Brazil scale showed excellent interobserver and intraobserver reliability, generating similar coefficients to those of the original scale version. The internal consistency of the NIPS was satisfactory ( Cronbach's alpha of 0.762) in the assessment of pain in 60 newborns during vaccination (18). Thus, the study of the NIPS scale permitted the high internal consistency demonstration.
Although the NIPS is a validated scale that presents psychometry well established, high reliability among the evaluators, consistent internal and concurrent validity for assessing pain in neonates, it may not be sensitive enough to evaluate the behavior of babies who need intensive care. The concurrent validity between the NIPS and NAPAS (Infant Neonatal Acute Pain Assessment Scale) in the evaluation of 34 neonates undergoing the 60 procedures painful (puncture of the heel and aspiration) were high (0.751 and 0.873) (26). Therefore, in the present study, the psychometric findings were satisfactory for the NIPS scale.
The result of the Spearman test allows the observation of a significant correlation between the scales NIPS and PIPP-R only the first condition (p <0.001) which may have occurred is in the first condition aspiration was performed without any intervention non - pharmacological, and thus the pain was more evident and more easily assessed.
In the study of Xie et al., conducted with 111 babies prematurely undergoing heel blood collection in the NICU, to evaluate the efficacy of four scales for assessment of pain neonatal, the nurses consider the PIPP easy to use, easy to score, and more accurate. On the other hand, NIPS took less time, probably because its items are easier to remember and evaluate. The study indicated that the PIPP and NIPS are the best choices compared to the other two scales. In routine intense within the NICU, doctors prefer to choose a range of easy-to-use, easy scores, which consumes little time and has good viability clinic (14). The present study didn't analyze the scales' application time; however, evaluators considered the rankings easy to understand and apply.
In the present study, the NIPS scale seems to have better clinical feasibility and applicability when compared to the PIPP-R scale since its scores are easy to understand and more concise. However, the NIPS scale does not measure pain intensity.
This study has strong points related to the study's design. The evaluators are professional experts with extensive experience in Neonatal Physiotherapy and have used two instruments validated and widely used in clinical practice. However, it presented the limitation of not having assessed the professionals' preference with applying the scale and practical applicability of the instruments in a sample of physical therapists in the area.
So choose one as valid, reliable, feasible, and practical aids the health professionals to make the best control of pain, improving the quality of care to the patient, especially of newborn premature that are most vulnerable.
Despite the difficulties encountered by realizadação in this study, the results showed that the two scales showed good Correlation only during the suction procedure without intervention. The pain was more evident in the premature newborn sample. In addition, the scales showed good reliability, internal consistency, and reliability among the evaluators. Thus, we suggest that both the PIPP-R and the NIPS good clinical validity and are one good choice to evaluate babies' pain during the procedure aspiration.
This study provides a reference to assist the professionals of health who work in the NICU to choose and use best the pain assessment scales in premature newborns. We suggest that further developed studies better apply these scales, particularly during the vacuum procedure, and evaluate the pain before, during, and after the process.