Developmental Care of the Preterm Infant - Assignment Example

The Detrimental Effect Of Noise And Environmental Sounds In The Developmental Care Of The Preterm Infant Introduction: A marked increase in the incidence of low and very low birth weight infants has been witnessed in the last several decades. The hospital care of premature, low birth weight infants requires appropriate technology and personnel, which is expensive; in the United States, the cost of care in the Neonatal Intensive Care Unit (NICU) and Intermediate ICU averages between $1,000 and $2,000 per day per patient, or over 3.5 billion dollars a year to the exchequer. These infants, who suffer various degrees of cognitive handicaps, require additional expenditure in the form of special education and continued medical care, which can be larger than the initial costs for their NICU care1. Noise and vibration are stressors that may adversely affect the well-being of infants and children being treated in intensive care units (ICU). Many studies have highlighted the detrimental effects of the sounds and noises which are an integral part of any NICU equipped with the latest paraphernalia. There are other studies which have demonstrated the advantage of protecting the neonate from such sounds; there are some studies which have supported the role of music therapy in the intensive care of preterm infants,2, 3, 4 but these remain controversial. In this essay I will discuss the role of environmental sounds and noises in the developmental care of the preterm neonate, and summarize the scientific evidence in favor of excluding harsh sounds from the ICUs. I will conclude by mentioning the recommendations regarding management of sound and noise vis-à-vis the preterm neonate. How the sensory environment affects the preterm newborn: Neonatal Intensive Care Units have been in existence for over 40 years; in these years, there has been a slow shift from the general idea that the newborn is passive and largely oblivious to his surroundings, to the universal recognition that environmental stimuli are perhaps more important to study in neonates than in any other age group. Whereas lighting has a vital role in visual processing after the newborn period and bears a powerful psychological impact for adults, these facets are of little importance to the preterm neonate, whose retina and visual cortex are the last of the physical senses to develop5. The retinohypothalamic tract and suprachiasmatic nuclei are sufficiently developed by early in the third trimester to respond to changes in light levels, and studies comparing continuously bright or dim lighting in the NICU with day–night cycled lighting have shown that preterm infants entrain more quickly to a circadian light stimulus when they have been exposed to that environment in the NICU. On the other hand in the preterm below 28 weeks of gestation, excessive light stimulation may be detrimental to the development of other sensory system, especially at a stage when the auditory cortex is undergoing rapid development; he calls this process inter-sensory interference which has been demonstrated in animal studies during critical periods of sensory development. Prenatal hearing: The intrauterine environment that the premature infant has been suddenly forced to exit is not without any auditory stimulation The acoustic environment of the fetus is composed of continuous cardiovascular, respiratory, and intestinal sounds that are punctuated by isolated, shorter bursts during maternal body movements and vocalizations. The distribution of sounds is confined to frequencies below 300 Hz. Additionally, vibrations on the external surface of the maternal abdomen can induce sounds inside the uterus6. There is mounting evidence that the fetus is able to retain the memories of auditory experience during intra-uterine life into early postnatal life. Even while inside the womb, babies learn to adapt to their mother’s breathing, her movements, and her voice as she speaks or sings. They can hear the sounds of the blood flow through the placenta7. Research has been conducted on newborn responses to naturally occurring stimuli such as heartbeats, intrauterine recordings, pre- and postnatal versions of the maternal voice, father's voice, and unfamiliar voices, which show that the newborn appear to recognize sounds they are likely to have heard during their intra-uterine existence. It has been shown that fetuses as small as 16 weeks gestation can respond to outside sound in Ultrasound studies8. Intrauterine recordings performed using sophisticated instruments show that the prosodic features of speech (pitch contours, rhythm, and stress) are available to the fetus. This is compatible with the kind of responses displayed by the newborn and this data suggests that these sounds may contribute to language acquisition during the first year9. A meta-analysis of 212 studies spanning the last 70 years showed that the womb accounts for 20% of the shared IQ component of identical twins separated at birth10. Postnatal noise exposure: The hospital care of premature and low-birth infants requires expensive technology and experienced care. While it is felt that sensory stimulation is necessary for optimal neurological development in children, the sights and sounds of the modern NICU provide an inappropriate sensory environment for the premature infant11. An infant in the NICU is exposed to average ambient noise levels ranging from 50 TO 88 dB, with peak levels of over 100 dB from sources such as ventilators, monitor alarms, incubator fans and motors, conversations, radios, telephones, water faucets, and cabinet doors12 Excessive sound is an acknowledged problem in neonatal intensive care units (NICUs)13; however, there is relatively little objective information about the effects of sound on the newborn. The cardiovascular and respiratory systems have been the most extensively studied systems. The patterns of response in these systems may be influenced by a variety of factors, including: the intensity of the sound, the infant's behavioral state, the infant's maturity and postnatal age, and the perinatal history14. A number of studies conducted in the 1980’s, have looked at developmental care in the NICU15, 16. The importance of the environment, the appropriate level of stimulation, and the role of ambient noise in brain growth and integration of physiological and behavioral processes have been highlighted in these studies. Deprived of their normal intrauterine environment premature infants are highly susceptible to the adverse effects of stress in the NICU. This is reflected by heart rate variations, increasing oxygen consumption and decreased blood oxygen levels as well as marked blood pressure fluctuations, failure to thrive, and increased levels of agitation. The NICU infant, who cannot communicate feelings of pain, is still subject to the stress reaction to pain, with increases in the levels of several hormones involved in the stress response, such as catecholamines17. Benefits of noise reduction in the ICU: Zahr and Traversay18 undertook an investigation into the benefits of noise reduction by the use of earmuffs. In their study earmuffs were placed over the premature infants' ears to reduce noise intensity in the NICU while physiologic and behavioral responses were measured. Two sites were used to collect data: in the first setting, 17 low birth weight infants were randomly assigned to an experimental and a control group, whereas 13 infants from a second hospital acted as their own controls and were tested with and without earmuffs. Earmuffs that reduced the intensity of noise by 7 to 12 dB were worn by infants in the experimental group only during the observation periods. Infants in the control group were exposed to the usual noise in the NICU. The infant's physiologic and behavioral responses were observed for four 2-hour intervals, morning and evening, on two consecutive days. Most of the significant results were from the site at which infants acted as their own controls. When infants wore the earmuffs, they had significantly higher mean oxygen saturation levels and less fluctuation in oxygen saturation. Furthermore, these infants had less frequent behavioral state changes, spent more time in the quiet sleep state, and had longer bouts in the sleep state. The authors recommend that NICUs should develop aggressive antinoise policies to substantially and consistently reduce noise. Various authors have studied the noise produced by incubators; Saunders studied the effect of covering incubators with the idea of reducing noise in the NICU.They found significant differences between the covered and uncovered incubators' sound level readings noise level readings being lower with covered incubators. They concluded that covering incubators is one method to decrease environmental noise in the NICU19. Another study was performed to test the effect of acoustical foam on the level of noise inside the incubator and examine neonatal response behaviors to changes in environmental noise. Data on 65 premature neonates were collected over a 14-month period at a large teaching hospital. Sound levels, oxygen saturation, and infant states were measured and recorded during three study conditions: pre-study neonate in incubator, neonate in incubator with 5 x 5 x 1 inch acoustical foam pieces placed in each of four corners, and post-study recovery of neonate in incubator with foam removed. All state assessments were measured with oxygen saturation and sound level measurements every 2 minutes of the study for a total 40 minutes. The researchers were able to demonstrate a significant effect of acoustical foam in decreasing noise measurements inside the incubator. Neonatal response behaviors also showed positive changes with decreasing environmental noise measurements inside the incubator. The authors support the use of acoustical foam as one method of environmental noise management in the intensive care nursery. Since subjects exposed to higher noise levels required more prolonged oxygen support therapy, the authors advocate using a variety of noise control protocols20, 21. Music Therapy in the Neonatal ICU: Neonates and infants in ICUs who receive special developmental care show improved clinical outcomes with faster weight gain, earlier discharge from the hospital, and significant decreases in the cost of hospitalization. The practice of developmental care is extended further by the addition of music and other sounds21, 22) Significant increases in oxygen saturation as well as decreased levels of agitation and heart rate were found with the use of music. Some studies have shown a doubled daily weight gain when premature babies in the NICU were exposed to music therapy23. The continuous high-intensity noise in the neonatal intensive care unit (NICU) is both stressful and harmful for the premature infant. Some researchers have found evidence that loud noise can cause hearing loss and alter physiologic and behavioral responses. There is no sound evidence (pun unintended) that providing extra prenatal auditory stimulation benefits the developing child, and there are potential risks9. To summarize the findings in the above studies: 1. In the intra-uterine environment, fetuses are capable of hearing various sounds such as the mother singing, her heart beat, her intestinal sounds, the sound of blood flowing in the placenta, as well as ambient sounds. 2. The premature infant who is ejected out of this protected environment too early is deprived of many of the sensory stimulations he would otherwise have received; on the other hand, due to his low birth weight and other medical problems, he may be placed in an incubator and in the ICU for prolonged periods of time, a situation which not only deprives him of sensory stimulation of all types, but also exposes him to sounds which are harsh, loud and detrimental to his development. The fact that the simple use of earmuffs can contribute to greater development of the size of the head as well as cognitive abilities in later life is an indication of how serious these effects can be. 3. The exclusion of harsh and unpleasant sounds and the use of music therapy in the setting of neonatal high-dependency units have been documented to produce major positive changes in the neuropsychological development. Guidelines for Noise management for the preterm neonate: In the University of Florida, Tampa, Florida, a multidisciplinary group24 of clinicians and researchers reviewed the literature to present recommendations and conclusions for care of the unborn, the neonate and the preterm; they specifically looked at the literature on the effects of sound in the Neonatal High-dependency Units and established a series of guidelines. An Expert Review Panel reviewed the data and conclusions. The following recommendations were developed from the review of literature. The first 3 relate to maternal exposure to unpleasant sounds, and thereby, to indirect exposure to the unborn child. (1) Women should avoid prolonged exposure to low-frequency sound levels (< 250 Hz) above 65 dB(A) during pregnancy. (2) Earphones or other devices for sound production should not be used directly attached to the pregnant woman's abdomen. (3) The voice of the mother during normal daily activities, along with the sounds produced by her body and those present in her usual surroundings, is sufficient for normal fetal auditory development. The fetus does not require supplemental stimulation. Programs to supplement the fetal auditory experience cannot be recommended. (4) Infant intensive care units should incorporate a system of regular noise assessment. (5) Sound limit recommendations are to maintain a nursery with an hourly Leq of 50 dB(A), an hourly L10 of 55 dB(A) and a 1-second Lmax of 70 dB(A), all A-weighted, slow response scale. (6)Infant intensive care units should develop and maintain a program of noise control and abatement in order to operate within the recommended permissible noise criteria. (7) Care practices must provide ample opportunity for the infant to hear parent voices live in interaction between parent and infant at the bedside. (8) Earphones and other devices attached to the infant's ears for sound transmission should not be used at any time. (9) There is little evidence to support the use of recorded music or speech in the environment of the high-risk infant. Audio recordings should not be used routinely or left unattended in the environment of the high-risk infant. These recommendations, if followed, should provide an environment that will protect sleep, support stable vital signs, improve speech intelligibility for the infant, and reduce potential adverse effects on auditory development. Conclusions: The prematurely born infant is deprived of the familiar and comfortable environment in his mother’s womb at a stage when he is not ready for extra-uterine life. Thereafter, because of his immature systems and other incidental medical problems, he is likely to be kept in an intensive care unit with an incubator and myriad other paraphernalia which produce unfamiliar sounds that have detrimental effects on his neuro-behavioral development. Exclusion of these sounds, and provision of soothing music is likely to foster optimum growth and development. Many studies have proved beyond reasonable doubt that providing appropriate protection from harsh and unpleasant ambient sounds in the pediatric high-dependency unit have positive effects on the development of the premature neonate. References: 1. Lewit, E.M., Baker, L.S., Corman, H., and Shiono, P.H. (1995).  The direct cost of low birth-weight.  Chapter 3 "Low Birth Weight" The Future of Children, The David and Lucille Packard Foundation, 5(1), 35-56. 2. Effects of music therapy on oxygen saturation in premature infants receiving endotracheal suctioning. Chou LL, Wang RH, Chen SJ, Pai L. Tri-Service General Hospital. 3. Pediatr Nurs. 1998 Nov-Dec;24(6):532-8. The effect of music and multimodal stimulation on responses of premature infants in neonatal intensive care. Standley JM.Center for Music Research, Florida State University, Tallahassee, USA. 4. J Pediatr Nurs. 2003 Jun;18(3):169-73. The effect of music-reinforced nonnutritive sucking on feeding rate of premature infants. Standley JM. Center for Music Research, Florida State University, Tallahassee, FL 32306-1180, USA. jayne.standley@cmr.fsu.edu 5. (Robert D White Director, Regional Newborn Program, Memorial Hospital, Indiana The Physical Environment of the Neonatal Intensive Care Unit – Implications for Premature Newborns and their Care-givers http://www.touchbriefings.com/pdf/1268/White.pdf 6. Robert M Abrams PhD and Kenneth J Gerhardt PhD The Acoustic Environment and Physiological Responses of the Fetus Journal of Perinatology December 2000, Volume 20, Number 8s, Pages S31-S36 http://www.nature.com/jp/journal/v20/n1s/abs/7200445a.html 7. Gerhardt, K.J., Abrams, R.M. (1996).  Fetal hearing:  characterization of the stimulus and response.  Seminars in Perinatology, 20(1), 11-20. 8. Hepper, P.G., Shahidullah, B.S. (1994). Development of fetal hearing. Archives of Disease in Childhood, 71, F81-F87. 9. Christine M Moon PhD and William P Fifer PhD Evidence of Transnatal Auditory Learning Journal of Perinatology 2000; 20:S37-S44. 10. Devlin, B., Daniels, M., and Roeder, K. (1997).  The heritability of IQ. Nature, 388,  468-471. 11. Collins, S.K. (1996).  Music therapy and nursing in the neonatal intensive care unit. In:  M.R.Froehlich (Ed.) (pp.73-76). Music Therapy with Hospitalized Children, Cherry Hill, NJ:  Jeffrey Books. 12. (Lynam, L. (1995).  Developmental care in the intensive care nursery:  putting prevention into practice.  Neonatal Intensive Care, Sept-Oct, 37-41. 13. J Otolaryngol. 2002 Dec; 31(6):355-60. Excessive noise levels in the neonatal ICU: potential effects on auditory system development. Kent WD, Tan AK, Clarke MC, Bardell T. Department of Otolaryngology, Faculty of Medicine, Queen's University, Kingston, Ontario. 14. Brenda H Morris MD1, M Kathleen Philbin PhD RN1 and Carl Bose MD Physiological Effects of Sound on the Newborn Journal of Perinatology 2000; 20:S55-S60. http://www.nature.com/jp/journal/v20/n1s/abs/7200451a.html ) 15. Als, H.A., Lawhon, G., Duffy, F.H., McNulty, G.B., Gibes-Grossman, R., and Blickman, J.G. (1994).  Individualized developmental care for the very low birth-weight preterm infant.  Journal of the American Medical Association, 272 (11),  853-858. 16. Petryshen, P., Stevens, B., Hawkins, J., and Stewart, M. (1997). Comparing nursing costs for preterm infants receiving conventional vs. developmental care.  Nursing Economics 15 (3), 138-150. 17. (Arnand, K.J., Hickey, P.R. (1987).  Pain and its effects in the human neonate and fetus.  New England Journal of Medicine, 317, 1322-1329. 18. Zahr, L.K., Traversay, J.D. (1995). Premature infant responses to noise reduction by earmuffs:  effects on behavioral and physiologic measures. Journal of Perinatology, 15(6), 448-455. 19. Pediatr Nurs. 1995 May-Jun;21(3):265-8. Incubator noise: a method to decrease decibels. Saunders AN. 20. Johnson AN. Pediatr Nurs. 2001 Nov-Dec;27(6):600-5. Neonatal response to control of noise inside the incubator. University of Delaware, Christiana Hospital's Special Care Nursery, Newark, DE, USA. 21. Kathleen Kolberg Recommended Standards for Newborn ICU Design Report of the Fifth Consensus Conference on Newborn ICU Design; January 2002; Clearwater Beach, Florida; Committee to Establish Recommended Standards for Newborn ICU Design;Robert D. White, MD, Chairperson; Memorial Hospital, South Bend, Indiana http://www.nd.edu/~kkolberg/DesignStandards.htm 22. MUSIC LISTENING IN NEONATAL INTENSIVE CARE UNITS Fred J. Schwartz, M.D. Piedmont Hospital Atlanta, GA Ruthann Ritchie, MT-BC North Memorial Medical Center Minneapolis, MN Accessed 03-19-2006 http://www.transitionsmusic.com/Final_version_Dileo.html 23. Akush Ginekol (Sofiia). 2004;43 Suppl 4:29-31.[Therapeutic effects of music on preterm infants in neonatal intensive care units][Article in Bulgarian] Malinova M, Malinova M, Krusteva M. 24. Graven SN. Sound and the developing infant in the NICU: conclusions and recommendations for care.J Perinatol. 2000 Dec; 20(8 Pt 2):S88-93. Medline 03-21-2006 Read More