The impact of earmuffs on vital signs in the neonatal intensive care unit

Abstract

Introduction: Elevated sound levels in neonatal intensive care units may cause undesirable effects and influence the stability of vital signs in moderately sick newborn infants. Objective: To evaluate the effect of using on the seven most common vital signs in newborns in NICUs. Methods: This is a prospective controlled study. All term and pre-term infants admitted to the NICU were randomized to either an or a earmuffs area and underwent hourly measurements and recording of vital signs during routine NICU activity for three consecutive days. Data were collected by sampling data from the routine continuous monitoring of heart rate (HR), respiratory rate (RR), oxygen saturation (OSAT), blood pressure (BP), FIO2 requirement, pain score (PS), and temperature (T). Exclusion criteria included neonates on high frequency ventilation, sedation and congenital anomalies with possible auditory system involvement. Results: The study included 182 infants; of them 100 infants completed the 72-hour measurements. Vital signs of fifty newborn infants in each group were recorded for a period of 72 hours. During this time, the observed linear increase in heart rate was significantly reduced within the group (139 versus 146 beat per minute) with p value <0.001, which also exhibited a similar significant decrease in systolic BP, although there was no evidence of significant difference between-group effect for diastolic BP and mean blood pressure. The average RR in the EM group was significantly lower than the NEM group for the entire 72-hour period (0.001), while temperature showed no significant difference between the two groups across the same time-period. Earmuffs also conferred a small but significant improvement in the gradual increase of the average O2 saturation (p value = 0.01). Similar improvement due to could also be seen in the infants' requirement for oxygen (days); the average oxygen requirement was 1.8 days versus 2.5 days with p value of <0.001. Conclusion: Wearing inside the NICU had a positive effect on the infants' vital signs.