Contributed by David Wilson, MS, RNC
It has been estimated that approximately 1 to 3 newborn infants in the well newborn nursery and 2 to 4 newborns in the intensive care nursery will have significant hearing loss. The average age of hearing loss detection by conventional screening methods is approximately 14 months. This time lag may potentially lead to severe impairments in speech, language and cognitive development. Screening for newborn hearing impairment by family history and risk factors alone are estimated to identify only one-half of all cases of newborns with hearing impairment (American Academy of Pediatrics, 1999). In recent years it was recognized that infants born extremely preterm and infants receiving ototoxic drugs such as gentamicin and vancomycin were at higher risk for hearing loss. Consequently most of these infants received a hearing screening before discharge from the hospital. Improved technology has increased the quality of reliable tools for screening newborns for hearing loss regardless of gestational age at birth.
The American Academy of Pediatrics (1999) recommends universal comprehensive screening program for newborns in order to detect and refer infants with hearing impairment before the age of 3 months. Appropriate intervention for newborn hearing loss should optimally take place by the time the infant is 6 months old.
The two methods recommended for newborn hearing screening are the evoked otoacustic emissions (EOAE) and the auditory brainstem response (ABR). Either method alone or in combination are acceptable for detecting an acceptable maximal threshhold hearing loss of greater than or equal to 35 decibels in the better ear (American Academy of Pediatrics, 1999). Conversational speech is in the 20-50 decibel range. The ABR and EOAE are noninvasive and require little time (5-10 minutes), although the ABR requires more extensive training of personnel. The EOAE measures sound waves in the cochlea (inner ear) in response to clicks or tone bursts; small microphones are placed in the infant's external ear and a measured response to the stimulus is recorded. Fluid or debris such as vernix in the external or middle ear may negatively affect the EOAE. The ABR measures electroencephalographic waves (by scalp electrodes) occurring in response to clicks. The infant must remain quiet during the ABR exam but response is not affected by fluid or debris matter in the middle or external ear. An infant who does not pass the first screening may be referred for a second screening before one month of age; the latter may be performed on an outpatient basis. The Academy recommends that 100 % of all newborns be tested at least once prior to discharge from the institution, regardless of time of discharge. One suggestion is that the hearing screening be performed just prior to the newborn metabolic screening to facilitate tracking in the nursery. Parents need to give informed consent for the procedure. In order to expedite universal newborn hearing screening, the Academy of Pediatrics (1999) has also recommended that third -party reimbursement for such screening be implemented nationwide. The estimated cost for each infant to be screened in the newborn period is estimated to be in the range of $7.00 to $26.00.
Although this step has generated controversy, it is expected that early intervention for newborns and infants with hearing loss will be detected sooner and interventions implemented in order to improve the child's hearing and subsequent speech, language, and cognitive development.
Nurses play a vital role in the implementation of this program. Nurses involved in mother-baby care may educate parents regarding hearing screening and ensure that newborns are appropriately screened before discharge from the hospital. In addition, nurses in community health care may be involved with screening referrals and follow-up in infants and young children.
American Academy of Pediatrics, Task Force on Newborn and Infant Hearing: Newborn and Infant Hearing Loss: Detection and Intervention, Pediatrics 103(2): 527-530, 1999. www.pediatrics.org.
See Chapter 12 in Nursing Care of Infants and Children, 6th edition.
See Chapter 10 in Essentials of Pediatric Nursing, 5th edition.
March 15, 2002