Committee on Environmental Health. Noise: A Hazard for the Fetus and Newborn

Implementation and evaluation of an individualized developmental care program in a neonatal intensive care unit

PURPOSE

This study aims to detect differences in outcomes for very preterm infants after the introduction of developmental care in a neonatal nursery, and to evaluate the effect of developmental care on parental well-being.

DESIGN AND METHODS

Prospective before and after cohort study of very preterm babies, with education for all staff between cohorts.

RESULTS

No significant differences were found between cohorts for short-term outcomes for babies or parental anxiety levels or depression. All infants scored within normal temperament ranges at 4 months.

PRACTICE IMPLICATIONS

Developmental care is a safe practice model. The interdisciplinary study facilitated professional development and increased the knowledge of nurses.

Recommended permissible noise criteria for occupied, newly constructed or renovated hospital nurseries

OBJECTIVE

To base permissible noise criteria for occupied, new nurseries on research findings.

STUDY DESIGN

An interdisciplinary group of clinicians reviewed the literature regarding the effect of sound on the fetus, newborn, and preterm infant and based recommended criteria on the best evidence. An external panel subsequently reviewed the criteria.

RESULTS

The recommended criteria: Patient bed areas and the spaces opening onto them shall be designed to produce minimal ambient noise and to contain and absorb much of the transient noise that arises within the nursery. The overall, continuous sound in any bed space or patient care area shall not exceed: (1) an hourly Leq of 50 dB and (2) an hourly L10 of 55 dB, both A-weighted, slow response. The 1-second duration Lmax shall not exceed 70 dB, A-weighted, slow response.

CONCLUSION

The permissible noise criteria will protect sleep, support stable vital signs, and improve speech intelligibility for many infants most of the time.

A descriptive study of noise in the neonatal intensive care unit: ambient levels and perceptions of contributing factors

PURPOSE

To examine the baseline acoustic environment in several mid-Atlantic region neonatal intensive care units (NICUs) and investigate the perceived factors contributing to noise levels in these NICUs.

SUBJECTS

Quantitative data were collected from 3 urban, mid-Atlantic level IIIB and level IIIC NICUs. Qualitative data were collected via interview from 2 RNs employed in each of the study NICUs.

DESIGN

This was an exploratory descriptive study utilizing a mixed-methods approach. A quantitative method was used for sound-level data collection, and a qualitative method was utilized during interviews with nurses to examine perceptions of factors contributing to noise.

METHODS

Ambient sound levels, measured in decibels, were taken at 5-minute intervals over a 2-hour period during both day and night shifts in a central location at each NICU. In addition, nurses were interviewed using a standardized interview questionnaire, and these interviews were then reviewed to determine themes regarding perceived factors contributing to sound levels.

MAIN OUTCOME MEASURES

Hourly mean sound levels in each NICU ranged from 53.9 dB to 60.6 dB, with no statistically significant difference between noise levels recorded on day shift versus night shift, and no statistically significant difference among sites. Qualitative data showed that nurses' believed day shift to be louder than night shift and many perceived their own NICU as "pretty quiet." Key contributing factors to increased sound levels were stated as monitors or alarms, performing invasive procedures, presence of family, nurses or doctors giving report or rounds, and ringing phones.

PRINCIPAL RESULTS

Noise levels were found to be above the American Academy of Pediatrics-recommended 45-dB level and often louder than the 50-dB level, which should not be exceeded more than 10% of the time. The recommended impulse maximum of 65 dB was also exceeded. Environmental Protection Agency recommendations for hospitals include sound levels no louder than 35 dB on night shift; this standard was also violated.

CONCLUSIONS

Elevated sound levels need to be addressed in individual NICUs around the country. Further exploratory studies, as well as research regarding effective methods of decreasing sound levels in the NICU environment, are necessary. NICUs can implement behavioral and structural changes that can decrease the sound levels in the NICU environment and decrease the potential for exposure of patients to the harmful physiological effects of increased sound levels.

Diurnal cortisol levels and cortisol response in youths with obsessive-compulsive disorder

BACKGROUND/AIMS

Recent results indicate a role of the hypothalamic-pituitary-adrenal (HPA) axis in the pathophysiology of obsessive-compulsive disorder (OCD). Although childhood onset is common, the HPA axis has scarcely been studied in young OCD subjects. Therefore, the present study aimed at examining basal and response levels of salivary cortisol in a sample of young OCD subjects.

METHODS

Twenty-three children and adolescents with DSM-IV OCD were compared to a reference group of school children (n = 240-336). The basal cortisol rhythm was measured through saliva samples 3 times/day. The cortisol response to a psychological stressor (exposure therapy in the OCD group and a fire alarm in the reference group) was also examined.

RESULTS

Compared to the reference group, OCD subjects displayed higher early-morning cortisol values (p = 0.005) with no difference between the late-morning and evening values. The cortisol levels in the OCD group diminished in response to the psychological stressor, compared to a positive response in the reference group (p < 0.001). No relation was found between cortisol and clinical parameters.

CONCLUSION

These results support the idea that HPA hyperactivity, commonly found in adult OCD patients, is also present at an earlier stage of development, with specificity for the early-morning peak.

Music as a nursing intervention for preterm infants in the NICU

Although there is general agreement that noise in the neonatal intensive care unit should be reduced, there is controversy about the use of music as a developmental care strategy with prererm infants. Much literature supports using music with preterm infants, indicating that it enhances physiologic and neurobehavioral functioning, but some experts worry that music is overstimulating. This article presents evidence supporting the use of music with preterm infants as well as criticism of same. Recommendations for music interventions with preterm infants are discussed, although fUrther research is needed before specific guidelines can he established.

Sound spectral analysis in the intensive care nursery: measuring high-frequency sound

Uterine structures protect the fetus from high-frequency sounds (i.e., >500 Hz). Preterm infants are not protected from sound >500 Hz. It is necessary to assess sound frequencies to protect preterm infants from high-frequency sound. However, no noise measurement study has been reported using sound spectral analysis (SSA). This article reports the results of an SSA in two Level III neonatal intensive care units (NICUs). The results of the SSA indicated that significant high-frequency sound existed within the infant's immediate care environment. Results of SSA assessments may lend evidentiary support to clinical managers seeking to redesign traditional NICUs.

A descriptive study of noise in the neonatal intensive care unit. Ambient levels and perceptions of contributing factors

PURPOSE

To examine the baseline acoustic environment in several mid-Atlantic region neonatal intensive care units (NICUs) and investigate the perceived factors contributing to noise levels in these NICUs.

SUBJECTS

Quantitative data were collected from 3 urban, mid-Atlantic level IIIB and level IIIC NICUs. Qualitative data were collected via interview from 2 RNs employed in each of the study NICUs.

DESIGN

This was an exploratory descriptive study utilizing a mixed-methods approach. A quantitative method was used for sound-level data collection, and a qualitative method was utilized during interviews with nurses to examine perceptions of factors contributing to noise.

METHODS

Ambient sound levels, measured in decibels, were taken at 5-minute intervals over a 2-hour period during both day and night shifts in a central location at each NICU. In addition, nurses were interviewed using a standardized interview questionnaire, and these interviews were then reviewed to determine themes regarding perceived factors contributing to sound levels.

MAIN OUTCOME MEASURES

Hourly mean sound levels in each NICU ranged from 53.9 dB to 60.6 dB, with no statistically significant difference between noise levels recorded on day shift versus night shift, and no statistically significant difference among sites. Qualitative data showed that nurses' believed day shift to be louder than night shift and many perceived their own NICU as "pretty quiet." Key contributing factors to increased sound levels were stated as monitors or alarms, performing invasive procedures, presence of family, nurses or doctors giving report or rounds, and ringing phones.

PRINCIPAL RESULTS

Noise levels were found to be above the American Academy of Pediatrics--recommended 45-dB level and often louder than the 50-dB level, which should not be exceeded more than 10% of the time. The recommended impulse maximum of 65 dB was also exceeded. Environmental Protection Agency recommendations for hospitals include sound levels no louder than 35 dB on night shift; this standard was also violated.

CONCLUSIONS

Elevated sound levels need to be addressed in individual NICUs around the country. Further exploratory studies, as well as research regarding effective methods of decreasing sound levels in the NICU environment, are necessary. NICUs can implement behavioral and structural changes that can decrease the sound levels in the NICU environment and decrease the potential for exposure of patients to the harmful physiological effects of increased sound levels.

Iatrogenic environmental hazards in the neonatal intensive care unit

Premature infants in the neonatal intensive care unit (NICU) face many illnesses and complications. Another potential source of iatrogenic disease is the NICU environment. Research in this area, however, is limited.

Nível de ruído em unidade de terapia intensiva neonatal

OBJETIVO: Verificar o nível de ruído da Unidade de Terapia Intensiva Neonatal e identificar suas fontes. MÉTODOS: Estudo quantitativo, descritivo e exploratório, conduzido em uma Unidade de Terapia Intensiva Neonatal de São Paulo. A coleta de dados ocorreu de abril a maio de 2005, utilizando um dosímetro para 96 horas de registro do nível de pressão sonora e 9 horas de observação, para identificar as fontes de ruído. RESULTADOS: Registrou-se Leq entre 61,3 a 66,6 dBA, sendo maior nos dias do final de semana. Os valores dos picos variaram de 90,8 a 123,4 dBC, sendo mais elevados no período noturno. As principais fontes foram: alarme dos ventiladores, dos oxímetros, conversa entre profissionais e pais e outros. CONCLUSÃO: Considerando os efeitos deletérios do nível elevado de ruído sobre neonatos e equipe de saúde, os resultados demonstram a necessidade de intervenções em algumas rotinas e na conduta dos profissionais e familiares.

Patient safety issues in magnetic resonance imaging: state of the art

The presence of a static magnetic field (Bo), a radiofrequency field (RF), a dynamic gradient which varies in time and loud noises during an MR examination could increase patient risk. Specifically, a magnetic field could interfere with ferromagnetic material leading to one of the following five dangerous interactions: 1) projectile effect, 2) twisting, 3) burning, 4) artefacts and 5) device malfunction. The projectile effect is when an object is attracted by the magnet with the risk, as reported in literature, of hitting the patient, operators and/or the instrument. Objects which typically can undergo this effect are oxygen and helium cylinders, IV stands, cleaning trolleys, chairs, lamp holders, scissors, forceps, clampers, traction weights, monitoring instruments, and especially metallic splinters within the patient. Twisting (torsion) typically occurs with cerebral vascular clamps and cochlear implants. If parts of implants are involved a malfunction may result. Burns can be caused when electrically conductive material is introduced within the magnet, for example, ECG electrodes, monitoring cables and coils which are in contact with the patient's skin, as well as tattoos and eye-liners that contain iron-oxides. Artefacts can be induced by RF emission of implanted devices which can be mistaken for noise of the receiving coil. Implanted devices can induce signal voids which mask or simulate pathologies. Electrical or mechanical malfunction of implanted devices includes pacemakers which can stimulate inappropriately or at an elevated frequency yielding a distorted ECG with altered T-waves. The risk for patients can be reduced by specific educational programs within individual radiology departments which include other specializations and external referring physicians with the aim of developing a standardized safety protocol.

Noise in contemporary neonatal intensive care

Weekly sound surveys (n = 63) were collected, using 5 s sampling intervals, for two modern neonatal intensive care units (NICUs). Median weekly equivalent sound pressure levels (LEQ) for NICU A ranged from 61 to 63 dB (A weighted), depending on the level of care. NICU B L(EQ) measurements ranged from 55 to 60 dB (A weighted). NICU B was recently built with a focus on sound abatement, explaining much of the difference between the two NICUs. Sound levels exceeded 45 dB (A weighted), recommended by the American Academy of Pediatrics, more than 70% of the time for all levels of care. Hourly L(EQ)s below 50 dB (A weighted) and hourly L10s below 55 dB (A weighted), recommended by the Sound Study Group (SSG) of the National Resource Center, were also exceeded in more than 70% of recorded samples. A third SSG recommendation, that the 1 s L(MAX), should not exceed 70 dB (A weighted), was exceeded relatively infrequently (< 11% of the time). Peak impulse measurements exceeded 90 dB for 6.3% of 5 s samples recorded from NICU A and 2.8% of NICU B samples. Twenty-four h periodicities in sound levels as a function of regular staff activities were apparent, but short-term variability was considerable.

Noise Pollution: A Modern Plague

Noise is defined as unwanted sound. Environmental noise consists of all the unwanted sounds in our communities except that which originates in the workplace. Environmental noise pollution, a form of air pollution, is a threat to health and well-being. It is more severe and widespread than ever before, and it will continue to increase in magnitude and severity because of population growth, urbanization, and the associated growth in the use of increasingly powerful, varied, and highly mobile sources of noise. It will also continue to grow because of sustained growth in highway, rail, and air traffic, which remain major sources of environmental noise. The potential health effects of noise pollution are numerous, pervasive, persistent, and medically and socially significant. Noise produces direct and cumulative adverse effects that impair health and that degrade residential, social, working, and learning environments with corresponding real (economic) and intangible (well-being) losses. It interferes with sleep, concentration, communication, and recreation. The aim of enlightened governmental controls should be to protect citizens from the adverse effects of airborne pollution, including those produced by noise. People have the right to choose the nature of their acoustical environment; it should not be imposed by others.

MRI of the foetal brain

Ultrasound examinations for foetal brain abnormalities have been a part of the routine antenatal screening programme in the UK for many years. In utero brain magnetic resonance imaging (MRI) is now being used increasingly successfully to clarify abnormal ultrasound findings, often resulting in a change of diagnosis or treatment plan. Interpretation requires an understanding of foetal brain development, malformations and acquired diseases. In this paper we will outline the technique of foetal MRI, relevant aspects of brain development and provide illustrated examples of foetal brain pathology.

Magnetic resonance imaging of neonatal encephalopathy at 4.7 tesla: initial experiences

OBJECTIVES

The goals were to develop safe 4.7-T MRI examination protocols for newborn infants and to explore the advantages of this field strength in neonatal encephalopathy.

METHODS

Nine ventilated newborn infants with moderate or severe encephalopathy were studied at 4.7 T, with ethical approval and informed parental consent. The custom-made, 4.7-T-compatible, neonatal patient management system included acoustic noise protection and physiologic monitoring. An adult head coil was used. Acquisition parameters for T2-weighted fast spin echo MRI and a variety of T1-weighted methods were adapted for MRI of neonatal brain at 4.7 T. The pulse sequences used had a radiofrequency specific absorption rate of <2 W/kg.

RESULTS

Physiologic measures were normal throughout each scan. T2-weighted fast spin echo imaging provided better anatomic resolution and gray/white matter contrast than typically obtained at 1.5 T; T1-weighted images were less impressive.

CONCLUSIONS

With appropriate safety precautions, MRI of newborn infants undergoing intensive care is as feasible at 4.7 T as it is at 1.5 T; our initial studies produced T2-weighted fast spin echo images with more detail than commonly obtained at 1.5 T. Although T1-weighted images were not adequately informative, additional pulse sequence optimization may be advantageous. A smaller neonatal head coil should also permit greater flexibility in acquisition parameters and even more anatomic resolution and tissue contrast. In neonatal encephalopathy, interpretation of the T2-weighted pathologic detail in combination with comprehensive neurodevelopmental follow-up should improve prognostic accuracy and enable more patient-specific therapeutic interventions. In addition, more precise relationships between structural changes and functional impairment may be defined.

Magnetic resonance imaging in preterm infants

MR imaging of the premature infant poses a number of challenges with regard to safety, sequence optimization and recognition of the normal appearances of the developing brain. In this paper we discuss these challenges, and review the common intracerebral abnormalities associated with premature birth. Although the outcome for very-low-birth-weight babies has improved over the last decade, there remains a significant risk of subsequent development of neurological disability. The relationship between MRI abnormalities and long-term outcome is considered.

Live music is beneficial to preterm infants in the neonatal intensive care unit environment

BACKGROUND

Music stimulation has been shown to provide significant benefits to preterm infants. We hypothesized that live music therapy was more beneficial than recorded music and might improve physiological and behavioral parameters of stable preterm infants in the neonatal intensive care unit.

METHODS

Thirty-one stable infants randomly received live music, recorded music, and no music therapy over 3 consecutive days. A control of the environment noise level was imposed. Each therapy was delivered for 30 minutes. Inclusion criteria were postconceptional age > or = 32 weeks, weight > or = 1,500 g, hearing confirmed by distortion product otoacoustic emissions (DPOAEs), and no active illness or documentation of hyperresponsiveness to the music. Heart rate, respiratory rate, oxygen saturation, and a behavioral assessment were recorded, every 5 minutes, before, during, and after therapy, allowing 30 minutes for each interval. The infant's state was given a numerical score as follows: 1, deep sleep; 2, light sleep; 3, drowsy; 4, quiet awake or alert; 5, actively awake and aroused; 6, highly aroused, upset, or crying; and 7, prolonged respiratory pause > 8 seconds. The volume range of both music therapies was from 55 to 70 dB. Parents and medical personnel completed a brief questionnaire indicating the effect of the three therapies.

RESULTS

Live music therapy had no significant effect on physiological and behavioral parameters during the 30-minute therapy; however, at the 30-minute interval after the therapy ended, it significantly reduced heart rate (150 +/- 3.3 beats/min before therapy vs 127 +/- 6.5 beats/min after therapy) and improved the behavioral score (3.1 +/- 0.8 before therapy vs 1.3 +/- 0.6 after therapy, p < 0.001). Recorded music and no music therapies had no significant effect on any of the tested parameters during all intervals. Both medical personnel and parents preferred live music therapy to recorded music and no music therapies; however, parents considered live music therapy significantly more effective than the other therapies.

CONCLUSIONS

Compared with recorded music or no music therapy, live music therapy is associated with a reduced heart rate and a deeper sleep at 30 minutes after therapy in stable preterm infants. Both recorded and no music therapies had no significant effect on the tested physiological and behavioral parameters.

Sound level exposure of high-risk infants in different environmental conditions

PURPOSES

To provide descriptive information about the sound levels to which high-risk infants are exposed in various actual environmental conditions in the NICU, including the impact of physical renovation on sound levels, and to assess the contributions of various types of equipment, alarms, and activities to sound levels in simulated conditions in the NICU.

DESIGN

Descriptive and comparative design.

SAMPLE

Convenience sample of 134 infants at a southeastern quarternary children's hospital.

MAIN OUTCOME VARIABLE

A-weighted decibel (dBA) sound levels under various actual and simulated environmental conditions.

RESULTS

The renovated NICU was, on average, 4-6 dBA quieter across all environmental conditions than a comparable nonrenovated room, representing a significant sound level reduction. Sound levels remained above consensus recommendations despite physical redesign and staff training. Respiratory therapy equipment, alarms, staff talking, and infant fussiness contributed to higher sound levels.

CONCLUSION

Evidence-based sound-reducing strategies are proposed. Findings were used to plan environment management as part of a developmental, family-centered care, performance improvement program and in new NICU planning.

Elevated sound levels within a busy NICU

PURPOSE

Elevated sound levels in the NICU may contribute to undesirable physiologic and behavioral effects in preterm infants. This study describes sound levels in a busy NICU in the southeastern U.S. and compares the findings with recommended NICU noise level standards.

DESIGN

NICU sound levels were recorded continuously at nine different locations within the NICU. Hourly measurements of loudness equivalent (Leq) sound level, sound level exceeded 10 percent of the time (L10), and maximum sound level (Lmax) were determined.

SAMPLE

Sound levels were sampled from nine different locations within the NICU.

MAIN OUTCOME VARIABLE

Sound levels are described using the hourly, A-weighted Leq, L10, and Lmax.

RESULTS

The overall average hourly Leq (M = 60.44 dB, range = 55-68 dB), L10 (M = 59.26 dB, range = 55-66 dB), and Lmax (M = 78.39, range = 69-93 dB) were often above the recommended sound levels (hourly Leq <50 dB, L10 <55 dB, and 1-second Lmax <70 dB). In addition, certain times of day, such as 6-7 AM and 10 AM-12 noon, were noisier than other times of day.

Conhecimentos e práticas dos profissionais de saúde sobre a "atenção humanizada ao recém-nascido de baixo peso - método canguru"

OBJETIVO: identificar os conhecimentos e as práticas sobre a Atenção Humanizada ao Recém-Nascido de Baixo Peso - Método Canguru (AHRNBP-MC) de profissionais médicos e de enfermagem em maternidades públicas da cidade do Rio de Janeiro. MÉTODO: estudo descritivo transversal realizado através de questionário. Participaram das entrevistas 148 médicos e enfermeiros atuantes nestas unidades. Destes, os 116 profissionais que atuam exclusivamente na unidade intensiva responderam sobre quesitos específicos das práticas assistenciais sobre a perspectiva da AHRNBP-MC. RESULTADOS: em relação às estratégias apontadas para minimizar ruído e luminosidade, 39% dos profissionais referiram atender rapidamente aos alarmes/cuidados no uso dos equipamentos e 88% apontaram a diminuição da luminosidade em pelo menos 1 período em 24h. Como estratégias para dor/desconforto, 34% referiram usar a sucção não-nutritiva e 9% citaram utilizar glicose. Oitenta e três porcento relataram serem as informações do quadro clínico as principais informações aos pais na 1ª visita. O exame físico é o procedimento em que é permitida a presença da mãe para 73% dos entrevistados. Cinquenta e nove porcento usavam a estabilidade clínica como critério para a ida do bebê ao colo materno pela primeira vez. CONCLUSÃO: apesar do conhecimento teórico sobre a Atenção Humanizada, os profissionais ainda não o utilizam plenamente em sua prática clínica, sugerindo que ainda não está completamente assimilada a abrangência dessa forma de cuidado neonatal.

[Noise generated during incubator manipulation: implications for nursing care]

Uncontrolled experimental study.

AIM

Quantify the impact noise of the 23 incubators functioning in the intensive and intermediate care units of a public university hospital in Ribeirão Preto-SP.

METHODOLOGY

Measuring occurred during incubator manipulation in a careful and in a rough way, considering the impact noise generated by the various situations in which the incubator was manipulated.

RESULTS

In practically all manipulation situations in both the careful and the rough way, group B presented higher NPS, followed by group A and D. Group C demonstrated the lowest NPS during the different manipulation situations. Even careful manipulation generated a strong noise level, and NPS almost always doubled or tripled when the same situation was realized roughly. Careful manipulation, together with lower incubator use time, revealed to be effective in reducing the noise produced during equipment manipulation.

A review of the current use of magnetic resonance imaging in pregnancy and safety implications for the fetus

This paper presents an overview of the application of and risks of exposure to Magnetic Resonance Imaging (MRI) in pregnancy. It reviews the risks to the fetus by considering the hazards in terms of the three main components of an MRI system. These are the static magnetic field, the time-varying magnetic gradient fields and the pulsed radio frequency fields. The hazards discussed are biological effects, miscarriage, heating effects and acoustic noise exposure. This paper also presents a survey of MRI sites within the United Kingdom to ascertain the extent of MRI usage in pregnancy. To validate the situation of MRI in pregnancy a survey was sent to 352 MR units throughout the United Kingdom. The questions were grouped to assess (a) maternal MRI diagnosis (b) fetal MRI and (c) work practices for pregnant MRI staff. The results showed that 91% of sites were imaging pregnant women in need of diagnosis in the second and third trimester. This paper highlights that MRI can add information for fetal central nervous system abnormalities identified by ultrasound screening, however within the UK direct fetal imaging was only performed in 8% of sites. This paper indicates the need for research to be undertaken for specific MRI clinical conditions. It also advises that risk assessment for pregnant staff working in MRI is performed, and that there is a clear need for further research into the effects of MRI in pregnancy as there is a need for clear authoritive advice.

[Noise in neonatology, the impact of hospital staff]

OBJECTIVES

To identify the various sources of noise in a neonatal intensive care unit in a university hospital centre and to assess the noise level.

METHODS

The nursing staff was interviewed to obtain a qualitative assessment of the noise in the department. Quantitative observations using a sound level meter and a dosimeter were then made. The measurements presented here were carried out in two different units caring for the newborn: on the heated table and in an incubator.

RESULTS

Many sources of noise were identified in the unit. They were responsible for a noisy environment, the level of which was far greater than current recommendations and left few periods of quiet. The alarms of the various monitors and maintenance apparatuses, the crying of the newborn and the activity of the staff were the principal sources of noise.

CONCLUSION

The impact of hospital staff on the extent and frequency of sources of noise is crucial. An enhanced awareness strategy should therefore be developed.

Long-term exposure to occupational noise alters the cortical organization of sound processing

OBJECTIVE

Long-term exposure to noise may cause an altered hemispheric lateralization of speech processing even in silent conditions. We examined whether this lateralization shift is speech specific or occurs also for other sounds.

METHODS

Brain responses from 10 healthy noise-exposed workers (>5 years) and 10 matched controls were recorded with a 32-channel electroencephalogram in two conditions, one including standard and deviant speech sounds, the other non-speech sounds, with novel sounds in both.

RESULTS

The deviant-sound elicited mismatch negativity (MMN) was larger to non-speech than speech sounds in control subjects, while it did not differ between the sound types in the noise-exposed subjects. Moreover, the MMN to speech sounds was lateralized to the right hemisphere in exposed workers, while it was left-hemisphere predominant in control subjects. No group topography difference was found for non-speech sounds. The deviant sounds that were close in formant space to the standards elicited a longer MMN latency in both speech and non-speech conditions in exposed subjects than controls. No group differences were found for cortical responses to novel sounds.

CONCLUSIONS

Long-term noise exposure altered the strength and the hemispheric organization of speech-sound discrimination and decreased the speed of sound-change processing.

SIGNIFICANCE

Subpathological changes in cortical responses to sounds may occur even in subjects without a peripheral damage but continuously exposed to noisy auditory environments.

Behavioural and physiological reactivity to noise in the newborn

OBJECTIVE

To assess the electromyographic (EMG) and behavioural reactivity of a group of newborn infants exposed to noisy stimulation of various intensity recorded in the Paediatric intensive care Unit (PICU).

METHODS

The study was performed at the nursery of the Paediatrics Department (University of Padova) on a group of 21 healthy newborns (mean 39 weeks of gestation), assessed between 24 and 72 h after birth. The study involved taking EMG recordings of the corrugator supercilii muscle and assessing the infant's behaviour at the baseline (15 seconds before stimulation), during noisy stimulation (for 1-2 seconds) and during recovery (15 seconds in three subphases). The noises, previously recorded in PICU, had four different intensities and were administered in random order to all infants. Descriptive analysis and repeated-measures analysis of variance (anova) were performed on the EMG and behavioural data.

RESULTS

The infants demonstrated a significant reaction to the noises both in the EMG recordings and in behavioural changes, especially during intense noisy stimulation. The reaction lasted longer than the stimulation period, preventing the infants from returning to the baseline condition.

CONCLUSIONS

Exposure to high-intensity noise produced in PICU causes evident behavioural and physiological effects (EMG). This is a field of study that could have important repercussions, given the medium- and long-term effects of repeated noise stimulation.

Use of Sound-Absorbing Panel to Reduce Noisy Incubator Reverberating Effects

OBJECTIVES

To assess the amplification and distortion of noise in incubators by measuring noise levels from various sources under various conditions.

STUDY DESIGN

We recorded sound pressure levels (SPL) of background noise, baby crying, alarms and porthole closing with the incubator hood open or closed. Then we tried to reduce the sound level in the incubator by applying a sound absorbing panel to the ceiling of the hood.

RESULTS

The sound sources analysed produced very high SPL. In free field baby crying and porthole noise were, respectively, 81-83 dB and 70-71 dB, closing the hood they raised to 84-87 and 73-74 dB: this means that the noise perceived by a baby in the incubator had twice the SPL of the same noise emitted in a free field; alarm noise was 56-57 dB inside incubators. Sound emitted inside the hood was also distorted, i.e. it had different features from the same source in a free field. The insulating panel prevented amplification and distortion due to the hood and reduced the SPL of alarms. Only background noise did not decrease with the panel. Sound absorbing panel reduced baby's crying, porthole noise and alarm noise SPL to 82-85, 70-71 and 50-51 dB, respectively.

CONCLUSIONS

Incubators are reverberating environments, which amplify the baby's cry and other noises produced inside the hood. The frequency components of noises are altered by the hood. The sound absorbing panel reduced this phenomenon.

Adapting the neonatal intensive care environment to decrease noise

A protocol of environmental noise reduction was developed and tested over a 14-month period in a 70-bed tertiary care neonatal intensive care unit (NICU). Evidence-based research and a detailed sound assessment guided the development of the protocol. Modifications of caregiving activities and categorized changes in the physical environment were specific to the NICU tested; however, guidelines for adapting the protocol to other NICUs are explained as well as methods for implementation to promote staff awareness and cooperation are reviewed.

Noise and the premature infant: physiological effects and practice implications

Premature infants in the neonatal intensive-care unit often are exposed to continuous loud noise. This excess auditory stimulation creates negative physiological responses, such as increased heart and respiratory rates and decreased oxygen saturation. Modifying the neonatal intensive-care unit to reduce noise levels provides an environment more conducive to maturation and recovery from illness. This article reviews the literature addressing the pathophysiology and physiological changes of the premature infant in response to stress and discusses practice interventions for decreasing noise levels in the neonatal intensive-care unit. These interventions include installing sound absorbing materials and minimizing conversations of the staff.

Environmental noise retards auditory cortical development

The mammalian auditory cortex normally undergoes rapid and progressive functional maturation. Here we show that rearing infant rat pups in continuous, moderate-level noise delayed the emergence of adultlike topographic representational order and the refinement of response selectivity in the primary auditory cortex (A1) long beyond normal developmental benchmarks. When those noise-reared adult rats were subsequently exposed to a pulsed pure-tone stimulus, A1 rapidly reorganized, demonstrating that exposure-driven plasticity characteristic of the critical period was still ongoing. These results demonstrate that A1 organization is shaped by a young animal's exposure to salient, structured acoustic inputs-and implicate noise as a risk factor for abnormal child development.

Assessment of neonatal nurses' behaviors that prevent overstimulation in preterm infants

This study assessed the adoption by neonatal nurses of behaviors that prevent visual, auditory, and tactile overstimulations in preterm infants, as well as the intentions, attitudes, and subjective norms related to the adoption of these behaviors. The convenience sample consisted of 54 neonatal nurses working in three Montreal region teaching hospitals. A multiple-choice questionnaire, composed on the basis of a review of the literature and the Theory of Reasoned Action, was used for data collection. The results revealed that the nurses often adopted behaviors that prevented tactile overstimulation, and that their intentions, attitudes, and subjective norms all favored the adoption of such behaviors. However, more than the half of the nurses did not frequently adopt behaviors that prevent visual and auditory overstimulations, nor did their intentions, attitudes, and subjective norms favor the adoption of these behaviors. Findings suggest that neonatal nurses lack specific knowledge in this area and that they would benefit from the completion of an evidence-based educational program on the prevention of overstimulation of preterm infants prior to their employment in a Neonatal Intensive Care Unit (NICU).

Mean noise amounts in level II vs level III neonatal intensive care units

PURPOSE

To compare mean noise amounts in Level II NICUs with those in Level III NICUs after controlling statistically for the number of infants per unit.

STUDY DESIGN

A between-group design was used in measuring noise amounts.

SAMPLE

Noise amounts were sampled using a central site procedure during two time periods of approximately 25 minutes each (total time approximately 50 minutes) in five Level II NICUs and seven Level III NICUs in Colorado.

MAIN OUTCOME VARIABLE

Average noise amounts (in dB) from two time periods of approximately 25 minutes each (total time approximately 50 minutes).

RESULTS

Mean noise amounts were significantly higher in Level III NICUs (mean = 54.89 dB) than in Level II NICUs (mean = 49.07 dB). This result remained statistically significant even after correcting statistically for total number of babies present in each NICU during noise measurements.

Magnetic resonance imaging and the neonate

Over the past decade, advances in neuroimaging have given birth to a new field of diagnostic pediatric neurologic assessment that includes magnetic resonance imaging (MRI). This invaluable tool helps medical professionals to resolve many clinical and research questions related to neonatal neurodevelopment that other imaging technology cannot explain. Nurses and others who accompany infants to MRI would benefit from a better understanding of early neurodevelopment and of the neuroimaging procedure. Knowing the advantages and disadvantages of MRI techniques can help nurses be better patient advocates, parent liaisons, and caregivers to infants having MRI scans.

Facilitating infant adaptation: the nursery environment

The physical and social environment of the nursery is a direct and indirect influence on the development of premature infants. Qualities in the environment affect physiological stability and provide sensory experience that is relevant to brain development. Adaptation of the prematurely born infant to the unexpected surroundings of the neonatal intensive care unit can be facilitated when the infant's developmental needs are understood and characteristics of the environment are adapted accordingly. The need for environmental change is revealed by the infant's behaviour, that is, his interactions with the environment. The environment also affects the behaviour of caregivers, who like the baby need to be able to do their best in this challenging situation.

Cognitive and behavioral deficits in premature graduates of intensive care

A substantial number of VLBW graduates of intensive care develop cognitive and behavioral problems, even in the absence of neuroimaging abnormalities. Although this article has highlighted the potential, important, contributing role of medical and stressful, neonatal, environmental conditions to the development of these deficits, it is not all-encompassing, and there are additional prenatal (ie, in utero stress, drug exposure) and neonatal (ie, infectious) contributing factors. The long-term, outcome data presented in this article are pertinent to the more mature, VLBW infant, and it remains unclear and critically important to delineate the long-term, neurobehavioral outcome of those extremely low birth-weight survivors born at the cutting limit of viability.

Physical and Chemical Factors in the Home and Workplace before and during Pregnancy

OBJECTIVE

To present and discuss current knowledge about the relationship between physical and chemical factors in the home and workplace and adverse reproductive outcomes in the offspring.

DESIGN AND METHODS

Critical review of the scientific literature, focusing mostly on epidemiological research. Reviews and original papers involving human occupational and home exposures to physical and chemical agents and their relation to adverse reproductive outcomes were screened and commented upon.

RESULTS

Only a small proportion of the several thousands of occupational/home exposures have been adequately assessed for reproductive or developmental toxicity. This is reflected in the difficulties of identifying causal associations in humans and in the lack of data.

CONCLUSION

According to present knowledge, very few authors confirmed that reproductive hazards exist in environmental agents, but increased surveillance of occupational exposures in relation to workers' reproductive health is highly desirable in order to assess moderate risks.

Implementing developmentally supportive family-centered care in the newborn intensive care unit as a quality improvement initiative

Intensive care nursery personnel increasingly seek to practice developmental and family-centered care, but become frustrated when attempting implementation. Reports of effective change strategies for integration to practice are limited. This article presents a summary of one unit's experience using the performance improvement process to move toward a developmentally supportive, family-centered care delivery model. Results to date indicate that a comprehensive quality improvement process guided by a unit-based newborn developmental specialist can provide the framework to achieve the change from traditional, provider-centered, task-directed care to holistic, individualized, relationship-based care.

Adverse perinatal conditions and the inner ear

Epidemiological studies in a number of Western countries have attributed 6-14% of sensorineural hearing impairment from birth or early childhood to problems relating to the birth process [1-4]. In spite of this association it is not always clear in individual instances whether adverse perinatal conditions identified subsequently have been causative of a hearing loss or not. It is possible that the hearing impairment was the consequence of an earlier intrauterine insult or is a coincidental finding. Infants carrying genetic mutations for hearing loss may coincidentally experience perinatal stress. It is therefore important to investigate the cause of a hearing loss discovered in infancy irrespective of the history of the infant having experienced adverse conditions surrounding the time of birth.

Neurobehavioral deficits in premature graduates of intensive care--potential medical and neonatal environmental risk factors

There is growing evidence that a large number of very low birth weight infants are exhibiting neurobehavioral problems in the absence of cerebral palsy at follow-up that has extended into school age and adolescence. Many clinical factors (ie, chronic lung disease, recurrent apnea and bradycardia, transient hypothyroxemia of prematurity, hyperbilirubinemia, nutritional deficiencies, glucocorticoid exposure), as well as stressful environmental conditions, including infant-provider interaction, constant noise, and bright light, may act in combination to impact on the developing brain, even in the absence of overt hemorrhage and/or ischemia. Any potential intervention strategy designed to prevent cognitive and behavioral problems has to account for the numerous biological and clinical conditions and/or interventions, as well as postdischarge social and environmental influences.

Reducing light and sound in the neonatal intensive care unit: an evaluation of patient safety, staff satisfaction and costs

OBJECTIVES

To modify an existing Level III neonatal intensive care unit and to compare light and sound levels in the renovated nursery with an adjacent traditionally configured nursery. Further, to assess the impact of this practice on patient safety, staff perceptions of the nursery environments, and to document costs of renovation.

STUDY DESIGN

Prospective comparison of light and sound levels in identical six-bed patient rooms within an existing intensive care unit. One room was modified to reduce light and sound, and the other served as a control. Costs of renovation were documented. Patient characteristics, severity of illness and safety outcomes were documented following modifications. Physician and nursing staff were surveyed on their perceptions of the renovations.

RESULTS

Both light and sound were reduced with modifications that incurred modest costs. Patient safety was not influenced adversely by reduced light or sound levels. Staff members were highly satisfied with reductions in sound levels. Reactions to reduced lighting levels were more mixed and led to modification of bedside lighting.

CONCLUSIONS

Cost-effective renovations to an existing NICU are possible, desirable, and do not impact patient safety. The reductions achieved, however, are less than those reached with new construction.

Hospital noise pollution: an environmental stress model to guide research and clinical interventions

Hospital noise pollution: an environmental stress model to guide research and clinical interventions This commentary provides an expanded environmental stress model. Conceptual relationships between ambient stressors, ambient stress, and health are detailed. A three-part intervention, enhancement of person-environment compatibility, is specified. Details are provided on how this approach to reducing environmental pollution/hazards and sustaining these changes may be influenced by sociopolitical values, technological advances, and motivation for control over hazards. Personal variables thought to mediate the impact of environmental stress on health, including intrinsic sensitivity to specific hazards, personality, restricted capacities, other stress, culture, personal preferences, stage of life, gender, and perceived social support, are highlighted. Research results on the stress and health effects of hospital noise on patients and nurses are summarized to provide support for the model. Future directions for research are recommended. Implications of the model for nursing, including an environmental activist role in an interdisciplinary effort to plan and implement noise abatement interventions, are described.

Newborn auditory follow-up

Because hearing is a key component in the infant's development of speech, language, and cognition, early detection of infant hearing loss is critically important. The routine evaluation of hearing should include the identification of parental concerns regarding infant hearing as well as the assessment and diagnosis of infants with potential hearing impairment. Identification of hearing loss should be followed by early interventions to prevent developmental delays. This article promotes universal screening of newborn hearing. The article also provides a review of the embryogenesis of hearing and includes a breakdown of risks for hearing loss, recommendations for auditory testing, and suggestions for follow-up, early intervention, and support for families of infants with hearing impairment.

Prevention and management of pain and stress in the neonate

This statement is intended for health care professionals caring for neonates (preterm to one month of age). The objectives of this statement are to: increase awareness that neonates experience pain; provide a physiological basis for neonatal pain and stress assessment and management by health care professionals; make recommendations for reduced exposure of the neonate to noxious stimuli and to minimize associated adverse outcomes; and recommend effective and safe interventions that relieve pain and stress.

Prolonged use of pancuronium bromide and sensorineural hearing loss in childhood survivors of congenital diaphragmatic hernia

Sensorineural hearing loss (SNHL) is a significant neurologic morbidity in survivors of neonatal congenital diaphragmatic hernia (CDH), with a reported incidence of up to 60%. In a historical cohort study of 37 neonates with CDH, we investigated the use of pancuronium bromide (PB) and common ototoxic drugs during the neonatal period and their relationship to SNHL in childhood survivors. Survivors with SNHL (n = 23) had significantly higher cumulative dose of PB administered during the neonatal illness than survivors without SNHL (n = 14). The cumulative dose and duration of PB use significantly correlated (r = 0.66-0.81) and independently predicted (adjusted r (2) = 0.42-0.64) the greatest intensity (in decibels) and the widest band (lowest frequency in hertz) loss of SNHL. No differences were identified between survivors with and without SNHL regarding demographic and neonatal characteristics (including oxygenation and ventilation variables and the cumulative dose and duration of therapy with aminoglycosides, vancomycin, and furosemide), although survivors with SNHL had received a modestly higher cumulative dose of ethacrynic acid than survivors without SNHL. Although we show that prolonged administration of PB during the neonatal period is associated with SNHL in childhood survivors of CDH, further multicenter studies are required to investigate the possible etiologies of SNHL in this high-risk population.