Identifying Infants at Risk of Hearing Loss

Generally speaking all those infants admitted to Level 3 and some in Level 2 are at high risk of future hearing impairment. The Newborn Hearing Screening Committee of United States of America, which includes a panel of Otolaryngologists, Audiologists and Paediatricians suggest that 9 groups of high risk should be followed up with hearing tests. These are as follows:

1. Familial (member of family deaf. In Auckland this comprises the largest group of children with hearing defects).
2. CMV, rubella (or other congenital infections).
3. Immaturity (birthweight <1500g).
4. Malformation (of cranium or face, e.g. cleft palate, auricular deformity, not pre-auricular tags alone).
5. Hyperbilirubinaemia (>340μmol/L).
6. Meningitis.
7. Asphyxia.
8. Therapy with ototoxic drugs (where toxic levels reached, particularly loop diuretics and aminoglycosides in combination).
9. Prolonged mechanical ventilation (> 5 days).

Follow up of the above children will detect 50% of all deaf children in any community and give a greater yield of abnormal hearing testing. Therefore in New Zealand it is general strategy to screen all the above children within the first few months of life.  A newborn hearing screening programme is being developed at National Women's Hospital.

 Practically speaking this is accomplished as follows:

Referral BEFORE or AT discharge to:

1. Starship Hospital Audiology
   Fax:  Internal: 5972          External: (09) 307 8972
2. Middlemore Hospital if the family are in the South Auckland catchment area (south of Otahuhu, east of Panmure)

• Please include parent's telephone number with referral as the appointments are frequently phoned. 
• The testing in neonates is generally using auditory brain stem response audiometry which is an EEG based test. It does, however, have a relatively high false positive rate and re-testing will be needed in some cases. 
• Otoacoustic emissions may be added to testing.  A pilot otoacoustic emission screening programme is being developed at National Women's Hospital.

Suggested Plan for National Women's Health

Babies admitted to NICU are at high risk of hearing impairment.  

• All infants under 1500g, those who have suffered birth asphyxia or any of the other risk factors mentioned above, should be referred AT or PRIOR to discharge. 
• In cases of hyperbilirubinaemia, referral is suggested if the serum bilirubin was >340μmol /L.
  • Premature babies will be at greater risk with lower levels, but will be included under other categories, e.g. <1500g).

Once follow up has been organised, this fact should be recorded

• in the front sheet of the notes, 
• on the discharge letter to the General Practitioner, and
• at an appropriate place in the Health and Development Book, which is given to the parents and in which details are supervised by Plunket Society personnel.