Effect of non-nutritive sucking and sucrose alone and in combination for repeated procedural pain in preterm infants: A randomized controlled trial

Background: Sucrose combined with non-nutritive sucking provided better pain relief than sucrose or non-nutritive sucking alone in a single painful procedure. However, whether the combination of non-nutritive sucking with sucrose could obtain a significant difference in analgesic effect of the repeated procedural pain than any single intervention has not been established. Objective: To compare the effect of non-nutritive sucking and sucrose alone and in combination of repeated procedural pain in preterm infants. Design: Randomized controlled trial. Setting: A level III neonatal intensive care unit of a university hospital in China. Method Preterm infants born before 37 weeks of gestation were randomly assigned to four groups: routine care group (routine comfort through gentle touch when infants cried; n = 21), non-nutritive sucking group (n = 22), sucrose group (0.2 ml/kg of 20%; n = 21), sucrose (0.2 ml/kg of 20%) plus non-nutritive sucking group (n = 22). Each preterm infant received three nonconsecutive routine heel sticks. Each heel stick included three phases: baseline (the last 1 min of the 30 min without stimuli), blood collection, recovery (1 min after blood collection). Three phases of 3 heel stick procedures were videotaped. Premature infant pain profile (PIPP) score, heart rate, oxygen saturation and percentage of crying time were assessed by five independent evaluators who were blinded to the purpose of the study at different phases across three heel sticks. Data were analyzed by analysis of variance, with repeated measures at different evaluation phases of heel stick. Results: 86 preterm infants completed the protocol. During the blood collection and recovery phases, combination group, had lower PIPP score (4.4 +/- 1.5; 3.0 +/- 0.8), lower heart rate (138.6 +/- 7.9; 137.4 +/- 4.7), higher oxygen saturation (95.2 +/- 1.6; 96.0 +/- 1.2), and smaller percentage of crying time (11.5 +/- 8.6; 4.6 +/- 3.4), compared with the group has given non-nutritive sucking (9.3 +/- 1.3, 6.8 +/- 1.4; 154.2 +/- 9.0, 148.0 +/- 9.3; 92.9 +/- 2.4, 94.1 +/- 1.0; 44.2 +/- 9.6, 31.2 +/- 10.5; respectively) or sucrose (10.1 +/- 2.0, 7.4 +/- 1.6; 151.6 +/- 9.6, 147.9 +/- 6.9; 93.5 +/- 1.7, 94.5 +/- 1.2; 53.8 +/- 16.7, 35.2 +/- 13.9; respectively) or routine care (13.3 +/- 1.6, 10.6 +/- 1.9; 156.8 +/- 7.2, 151.7 +/- 7.9; 92.9 +/- 2.1, 93.8 +/- 1.6; 80.6 +/- 7.6, 68.2 +/- 9.9; respectively). Both non-nutritive sucking and sucrose were more effective in reducing preterm infants' PIPP score and percentage of crying time than routine care. There was no difference in PIPP score, heart rate, oxygen saturation and percentage of crying time between the non-nutritive sucking and sucrose groups. Conclusion: The combination of non-nutritive sucking with sucrose provided better pain relief during repeated painful procedures than when non-nutritive sucking or sucrose was used alone. The effect of non-nutritive sucking was similar to that of sucrose on repeated procedural pain.