The effects of noise reduction by earmuffs on the physiologic and behavioral responses in very low birth weight preterm infants.

OBJECTIVE: Preterm infants are exposed to loud noises during their stay in the neonatal intensive care unit which can lead to physiologic and behavioral alterations and even hearing loss. The use of earmuffs can reduce sound level and these changes. The objective of the present study is to evaluate the effectiveness of the earmuffs in preterm infants solely cared for in closed incubators. METHODS: A comparative prospective study comprising 20 clinically stable preterm infants weighing less than 1500 g cared in closed incubator was conducted. Preterm infants acted as their own controls whereby they were observed without earmuffs (Group 1) for 2 days and with earmuffs (Group 2) on consecutive 2 days. The preterm infants' physiologic responses and Anderson Behavioral State Scoring System (ABSS) scores were assessed over 30s every 2h for 8h during daytime for 4 days. RESULTS: Out of 20 preterm infants, 6 were male and 14 female with a mean birth weight of 1220 ± 209 g, gestational age of 29.9 ± 2.1 weeks. The total number of measurements was 320. The mean ABSS scores of Group 1 and 2 were 3.07±1.1 and 1.34 ± 0.3, respectively. Statistically significant difference was noted between the means of ABSS scores (p<0.001). Preterm infants with earmuffs (87.5%) were more frequently observed in a quiet sleep state of ABSS compared with those without earmuffs (29.4%). CONCLUSIONS: Noise level reduction was associated with significant improvement in behavioral states of ABSS. We suggest that noise reduction in preterm infants with earmuffs is helpful by improving sleep efficiency and increasing time of quiet sleep.

The relationship between leukemoid reaction and perinatal morbidity, mortality, and chorioamnionitis in low birth weight infants.

OBJECTIVES: Neonatal leukemoid reaction (NLR) is relatively rare and considered as a white blood cell (WBC) count ≥50×10(9)/l . The aim of this study was to investigate the association of NLR with neonatal morbidity and mortality and maternal chorioamnionitis in low birth weight infants. METHODS: In this case-controlled retrospective study, the medical records of 1200 newborn infants with a birth weight <2500g admitted to the neonatal unit over a period of 5 years were reviewed. The infants who developed features of NLR (n=17, 1.4%) formed the study group, while the remainder without NLR, matched for gestational age and birth weight (n=123), formed the control group. A chart review was performed and salient demographic, clinical, and laboratory data abstracted. A statistical analysis was subsequently performed on this data. RESULTS: The mean WBC and absolute neutrophil counts of infants with NLR were significantly higher than those in the control group. The peak time of NLR was at 7.9±3.6 (interquartile range (IQR) 1-30) days and on average it improved within 4.1±1.95 (IQR 2-9) days. It was noted that those infants with NLR were mostly born by vaginal delivery and their mothers had a higher rate of early rupture of the membranes and chorioamnionitis. NLR was associated with a 4-fold increase in sepsis, 20-fold increase in intraventricular hemorrhage, 54-fold increase in bronchopulmonary dysplasia, and 6-fold increase in mortality. In the study group, those infants whose mothers had chorioamnionitis had a higher rate of early rupture of the membranes and they developed sepsis and intraventricular hemorrhage more often than those whose mothers did not have clinical chorioamnionitis. CONCLUSIONS: In low birth weight newborn infants, NLR is significantly associated with sepsis, intraventricular hemorrhage, bronchopulmonary dysplasia, and a high mortality rate. Also, those infants with NLR are more likely to be born to mothers with chorioamnionitis and they face sepsis and intraventricular hemorrhage more often.