En verified after discharge that all infants who were recruited in this study had normal brainstem auditory responses (a routine procedure in all infants who are discharged from our NICE). The study was approved by the local institutional review board, and written informed consent was obtained from both parents of each infant. Design This study was a prospective, randomized trial with crossover of the effect of music (compared with no music) on ERE. The sequence in which exposure was given music first followed by no music or the opposite) was selected by randomization, by using random numbers. Each infant was studied on 2 consecutive days.
We tested only the music of Mozart present on the Baby Mozart CD (Baby Smart, Revolt, Israel), which was played on a mini-CD device at a volume of 65 to 70 db. Before the study, the CD system was calibrated according to the American Academy of Pediatrics recommendations not to exceed volume of 75 db and to maintain background noise near the infant’s ear 45 db. According to this acoustic measurement, speakers were laced inside the incubator at a distance of 30 CM from the infants’ ears. In both cerements, the environment was controlled to minimize possible unwanted noises and maintain noise constancy.
The monitor alarms were kept silent (visual alarm only), and the ward’s doors were closed to minimize outside noise. Music was Initiated 10 minutes before the beginning of the metabolic measurements and was continued for the 30 minutes of ERE recording. The same procedure was applied during the no-music exposure period. Importantly, no music was heard by the infants during the whole study period except for the 30 minutes of exposure related to the duty. Metabolic studies were conducted while the infants were prone and asleep and at the same time of the day (noon time) for all infants, starting 1 hour after the completion of the last feed.
The same type (breast milk versus formula) and amount of food was given to the infants on both study days. Measurements were stopped during body movements ( 5% of the time of measurement). During the metabolic study, infants were cared for in their own, convective incubator. Air temperature inside the incubator was skin corticosteroids to keep temperature over the back at ICC. Thus, the 2 energy expenditure measurements were made in nearly identical thermal environments. Measurements Metabolic measurements were performed by indirect calorimeter, by using the Deliberate II Metabolic monitor (Dates-Mohamed, Helsinki, Finland).
This instrument uses the principle of the open-circuit system that allows continuous measurements of oxygen consumption and carbon dioxide production using a constant flow generator. The measurement ranges for both oxygen consumption and carbon dioxide production of 5 to 2000 mini allow measurements in preterm infants with small tidal volumes. Before the mean METHODS Patients The study was conducted in the NICE at the Lisp Maternity Hospital, Tell Aviva Medical Center (Tell Aviva, Israel). We aimed to study healthy, growing, of 30 to 37 weeks.
Postmenopausal age was calculated in completed weeks on the basis of last menstrual period, consistent 1 week with early, fritterer’s ultrasound examination. All infants were clinically and thermally stable while cared for in a skin corticosteroids incubator. At the time of the study, they all were tolerating full internal feeding (1 50-160 ml/keg weight per day) without significant gastric residuals 5% of total feed), were PEDIATRICS Volume 125, Number 1, January 2010 cerement, the device performs a collaborations that is based on independently measured barometric pressure.
In addition, periodic testing for accuracy was performed by alcohol burning according to the manufacturer’s instructions. This method is safe and allows prolonged measurements while allowing reasonable access to the infant for routine care. Validation studies have shown the technique to give results equivalent to direct measurements. 8,9 In our hands, the instrument has an intra-assay coefficient of variation of 3%. For controlling for introverted variation, all measurements were performed by a single investigator (Dry Lubberly). Statistical Analysis This study is a pilot study that was designed to estimate the effect size of music on ERE.
Thus, an empirical number of 20 infants (e, 40 measurements) was chosen. Comparison of energy expenditure values between groups was performed by using paired t test. For this purpose, ERE results (recorded every minute by the instrument) were averaged over the first, second, and third 10-minute periods of the consecutive 30-minute total study time, whether it was a music or music exposure period. Results are expressed as means SD; P . 05 was considered significant. Assessed for eligibility (n = 20) Excluded (n = 2) Enrollment Is it randomized?
Tachycardia (n = 1) Excessive movements (n = 1) Music first: n = 5 No music first. N ; = 13 Allocation Lost to follow-up (n = O) Follow-Up Lost to follow-up (n Analyzed (n = 5) Analysis Analyzed (n = 13) Cohort flowchart. RESULTS Twenty preterm infants were recruited to the study (Fig 1). One of them was excluded because of tachycardia before the beginning of the measurement. Another 1 was excluded because of excessive body movements during the second measurement. He excessive movements of the infant were observed during the no-music session and thus could not have been an adverse effect of music.
Characteristics of the study infants are listed in Table 1 and describe their eye LUBBERLY et al gender, birth weight, gestational age, Pagan scores, weight, and chronological age at the time of the study, as well as major medications given or procedures undertaken. Of note, 8 of 18 infants received caffeine for a history of previous apneas of prematurely but did not have any active apneas, and there were no changes in drug dosage during both periods of the study. By randomization, 5 of 18 infants were first studied during the music period. Table 2 depicts the results of ERE measurements.
ERE was similar during the first 10-minute period of both randomization groups. During the next minute period, infants who were exposed to music had a significantly lower ERE than when not exposed to music (P . 028). This was also true during the third 10-minute period (P . 03). Thus, on average, the effect size of music on ERE is a reduction of 10% to 13% from baseline, an effect obtained within 10 to 30 minutes. When multiple regression analysis was used, the effect of music on ERE manned significant, even after we introduced the caffeine intake as a potential confounder.
DISCUSSION As hypothesized, we found in this pilot randomized clinical trial with crossover of music versus no music exposure that within 10 minutes of listening to Mozart music, healthy infants studied at a postmenopausal age of 30 to 37 weeks had a 10% to 13% reduction of their ERE. In our study, this effect TABLE 1 Demographic and Clinical Characteristics Characteristic Maternal age, y Mean SD Range Gravity, median (range) Parity, median (range) Prenatal steroids (Siltstone), n (%) Gender of infants (male/ female)