[Early detection of hearing impairment in high-risk infants of NICU].

OBJECTIVE

Hearing impairment or loss is a common disorder at birth. Many perinatal conditions may also cause hearing impairment. The present study aimed at investigating the incidence and morbidity of hearing impairment in critically ill neonates with high risk factors in neonatal intensive care unit (NICU).

METHODS

Patients were evaluated using the auditory brain-stem response (ABR) to detect hearing impairment or loss in 248 neonates stabilized or before discharge from the NICU during the period from Dec. 1999 to Aug. 2001 in SCMC. In this article, high risk factors of hearing loss included severe asphyxia, hyperbilirubinemia and very low birth weight, persistent pulmonary hypertension or on a ventilator, exposed to ototoxic medications such as aminoglycosides and diuretics, a family history of hearing loss, meningitis and craniofacial anomalies, etc. Screening test was performed with a 70 dB (SPL) hearing level click stimulus to each ear.

RESULTS

Seventy-two newborns had detectable hearing impairment in all the patients studied, the incidence of hearing impairment was 29.03%. Among them 3 cases had serious hearing loss. Twenty cases were among the 50 asphyxiated newborns (40.0%); 24 were from the 91 neonates with hyperbilirubinemia (26.37%); 15 were from the 44 premature infant group (34.09%), three of 4 premature cases with birth weight less than 1 500 g had hearing impairment. Six cases were among the 15 newborns who used mechanical ventilation (40.0%); 19 cases were among the 46 newborns who received ototoxic agents (41.30%).

CONCLUSIONS

Critically ill neonates with some specific high risk factors had a significantly high incidence of hearing impairment. Early hearing screening is necessary for neonates who are discharged from NICU.