[Automated infant auditory screening using the Natus-ALGO 2e in the NICU]

Natus-ALGO 2e, an automated ABR screener(Natus Medical, Foster City, CA, USA), compares the V wave of ABR evoked by 35-dB-nHL click stimuli by using a template-matching detection algorithm that provides only a pass-refer outcome. The aim of this study was to compare Natus-ALGO 2e with conventional ABR, and to evaluate its usefulness. The Natus-ALGO 2e screener was used to screen 202 ears of 101 neonates in our neonatal intensive care unit. The mean conceptional age at the time of screening was 40.4 +/- 3.0 weeks. 60 ears of 30 infants at high-risk of hearing impairment, including "refer" infants, were tested by the Natus-ALGO 2e and conventional ABR methods, and the results were compared. All neonates were tested with the Natus-ALGO 2e screener in a state of natural sleep, and screening time averaged 2 minutes 58 seconds. There were 97 cases in which both ears were passed, 3 cases in which both ears were referred, and one case in which one ear was referred. In comparison with conventional ABR, 53 of the 60 ears of 30 high-risk infants passed by the Natus-ALGO 2e method, whereas 14 of the 53 ears initially failed the conventional ABR screening. Of these 14 ears disagreements (the results of the Natus-ALGO 2e method passed, but the results of the conventional ABR failed), the results of the ABR screening changed to normal in 11 ears, and ABR showed improved threshold and latency in the other 3 ears after 5 weeks to 12 months. Among those that passed the Natus-ALGO 2e screening, the number of sweeps that failed the ABR screen was significantly greater than with normal ABR. Of the 7 ears of 4 patients that were referred on the basis of the Natus-ALGO 2e screening and failed by the conventional ABR method, 3 ears screened by the ABR method were normal when retested, and one ear passed by the Natus-ALGO 2e screening 12 weeks to 11 months later. In conclusion, Natus-ALGO 2e is useful for screening infant hearing because it can be performed quickly while the patient is sleeping naturally. In infants at high-risk for hearing impairment, the results of Natus-ALGO 2e and conventional ABR screening conflicted in numerous sweeps. Therefore, when there are many sweeps in high-risk infants, a retest should be performed that includes conventional ABR, even if they passed with Natus-ALGO 2e.