The effectiveness of music on pain among preterm infants in the neonatal intensive care unit: a systematic review.

REVIEW QUESTION/OBJECTIVE: The objective of this review is to synthesize the best available evidence related to the effectiveness of music as pain relieving method among preterm infants during painful procedures in the neonatal intensive care unit.Review questions are: Among preterm infants in the neonatal intensive care unit, is music effective in reducing BACKGROUND: Preterm infants (i.e. babies born at or before 37 gestational weeks) compose a patient group of the most vulnerable to pain. Infants treated in a neonatal intensive care unit (NICU) are exposed to a variety of painful procedures (e.g. heel prick, iv cannula insertion, endotracheal suctioning) and to environmental stress (e.g. noise, light). Simons et al., for example, described an average 14 +/- 4 painful procedures during the first 2 weeks of life within a period of 24 hours among 151 neonates. Many studies have shown that repeated and sustained pain can have direct and long-term consequences on the neurological and behavior-oriented development of the neonates during the rapid development phase of the central nervous system. Pain can cause detectable physiological, behavioral and hormonal changes and contribute to the altered development of the pain system during later childhood and adolescence. Instead, live music such as singing is excellent type of music when it is steady, constant, quiet, soothing and directed to the infants. Graven emphasizes that recorded sound should not replace human voice exposure in the NICU; therefore, health care providers should provide ample opportunity for the infant to hear parent's voices live, such as singing or humming, in interactions between the parent and the infant at the bedside.The AmericanAcademy of Pediatrics Committee on Environmental Health has recommended safe levels of sound, and these recommendations have been updated by an expert team of practitioners. Recommendations specify that continuous sound should not exceed an hourly equivalent sound level of 50 A-weighted decibels (dBA), and music as an auditory stimulus not exceed 75 dB in NICU. If earphones or other devices are used, sound sources should be kept at reasonable distances from the infant's ear, played for brief periods and at levels below 55 dB.Music listening can be initiated with or without the involvement of a music therapist. In this review, music can be implemented for premature infants by a music therapist or any health care providers and it will include both recorded and live music.

OUTCOMES: Regardless of the type of music, several studies have investigated the short term effects of music on preterm infants, including the improvement in physiological outcomes (e.g. oxygen saturation, heart rate, respiratory rate, and blood pressure), as well as in behavioural state (e.g. crying, facial expression, body movements) and pain scores. For example, Chou et al. showed that premature infants receiving recorded music, that was the combination of womb sounds and the mother singing, with endotracheal suctioning had significantly higher oxygen saturation than when they did not receive music. Butt & Kisilewsky compared recorded music involving both the vocal and instrumental version of Brahms lullaby versus no music, and found that infants older than 31 weeks demonstrated significant reduction in heart rate, behavioral state and pain.In the study of Arnon et al. the infants receiving live music, compared with infants receiving recorded music or no music, had significantly reduced heart rate and behavioral scores during the post-intervention period. Live music comprised of a lullaby sang by the female voice with frame drum and an accompanying harp. The same music was played by a tape recorder. Live music showed significant benefits, whereas no statistically significant changes were found for the recorded music and control groups. Teckenberg-Jansson et al. indicated that music therapy combined with kangaroo care decreased the pulse, slowed down the respiration and increased the transcutaneous oxygen saturation in preterm infants. The musical instruments used were a lyre and a female human voice, which hummed or sang.There is evidence that music has also positive consequences on long-term outcomes, including length of hospitalization, weight gain, and non-nutritive sucking. For example, in the study of Caine the preterm infants received music stimulation which consisted of recorded vocal music (including lullabies and children's music) and routine auditory stimulation. Exposure to the music stimulation had many positive effects on preterm infants, such as it increased daily average weight, formula and caloric intake, and significantly reduced total hospital stays and stress behaviors for the experimental group. In addition, according to Lubetzky et al. exposure to music by Mozart significantly lowered energy expenditure among healthy preterm infants.Hartling et al. have published a systematic review on the efficacy of music for medical indicators in term and preterm neonates. Nine randomized trials (1989-2006) were included. According to the results of this review music may have positive effects on physiological parameters and behavioral states, and may reduce pain and improve oral feeding rates among the premature infants. The effects of music were evaluated during medical procedures (circumcision, heel prick) and for other indicators. In addition, Cignacco et al. conducted a systematic literature review on the efficacy of non-pharmacological interventions in the management of procedural pain in preterm and term neonates during the period from 1984 to 2004. According to this review there was no clear evidence that the method of music could have a pain-alleviating effect on neonates. In the Cochrane Library, one systematic review is also available up to year of 2011 concerning non-pharmacological management of infants and young children (preterm, neonate, older up to three years) during procedural pain, but this review did not consider music as an intervention.To date, there is also one meta-analysis published by Standley concerning the efficacy of music therapy for premature infants during the period from 1950 to 1999. It concluded that music was beneficial for many outcomes among the preterm infants in the NICU. However, the results of this review were limited by the poor methodological quality of the included studies, and unclear reporting on the phases of review.In our systematic review, studies published in 2000 and after will be considered for inclusion in the review. The number of the RCT's concerning the effectiveness of music among the preterm infants in NICU is especially increased during the last few years, and these studies have not included in the previous systematic reviews and meta-analysis.