Audiological evaluation of very low birthweight infants.
A population of consecutively surviving very low birthweight (VLBW) infants comprising 41 infants (24 female) birthweight less than 1000 g and 108 infants (63 female) birthweight 1000-1500 g received detailed audiological evaluation. The audiological test battery comprised auditory brainstem evoked response (ABR) prior to hospital discharge, behavioural audiometry and tympanometry at 8-12 months and monitoring as necessary. The ABR results were interpreted with reference to a normative group of 36 full-term infants (birthweight 2.4-4.5 kg). Of the 142 VLBW infants completing audiological evaluation, one (0.7%) had evidence of moderate-severe high frequency sensorineural hearing loss, 83 (58.5%) evidence of conductive dysfunction (18 severe, 42 moderate and 23 mild) and only 58 (40.8%) normal hearing. The 19 infants with severe auditory impairment were more likely to have suffered moderate-severe apnoea, greater than or equal to two courses of mechanical ventilation, prolonged oxygen therapy and recurrent upper respiratory tract infections in the first year of life than infants without severe impairment (P less than 0.05). Because of the incidence of conductive pathology, difficulties occurred when attempting to compare ABR status at 36-42 weeks postmenstrual age with peripheral hearing status at 8-12 months as assessed by visual reinforcement orientation audiometry (VROA) and impedance audiometry. The most useful ABR test parameters as screening measures of peripheral auditory status were Wave I-III-V morphology, wave V threshold levels and wave V absolute latency values when used in combination as a test battery.(ABSTRACT TRUNCATED AT 250 WORDS)
Tudehope
D
D
Growth and Development Clinic, Mater Misericordiae Public Hospitals, South Brisbane, Queensland, Australia.
Smyth
V
V
Scott
J
J
Rogers
Y
Y
D000158:Acoustic Impedance Tests; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D005865:Gestational Age; D006309:Hearing / Q000502:physiology*; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis; D006801:Humans; D007230:Infant, Low Birth Weight / Q000502:physiology*; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D012016:Reference Values