title: Factors associated with permanent hearing impairment in infants treated with therapeutic hypothermia.
abstract: OBJECTIVE
  To define the incidence of hearing impairment, document plasma gentamicin concentrations, and identify factors associated with permanent hearing impairment in infants subjected to therapeutic hypothermia for moderate or severe neonatal encephalopathy.
  
  
  METHODS
  Data were collected prospectively in a regional center providing therapeutic hypothermia. Cooled infants at ≥ 36 weeks gestation with moderate or severe neonatal encephalopathy were analyzed if a full dataset was available (n = 108), including clinical variables and gentamicin trough levels. Infants with hearing impairment were identified, and survivors were followed up with neurodevelopmental evaluation at age 18 months. Stepwise logistic regression identified factors associated with hearing impairment.
  
  
  RESULTS
  Nine infants died, and among the survivors, 10.1% developed a permanent hearing impairment. The trough gentamicin level was above the recommended cutoff of 2 mg/L in 37% of the infants in the entire cohort and in 90% of the infants with hearing impairment. Logistic regression analysis identified high trough gentamicin level, low cord pH, and hypoglycemia (<46.8 mg/dL) in the first postnatal hour as significantly associated with hearing impairment. The need for inotropic support was close to significant (P = .055).
  
  
  CONCLUSIONS
  Hearing impairment was a common finding among cooled infants. Plasma gentamicin levels were commonly >2 mg/L. Based on these findings, we propose changes in gentamicin dosing interval and trough level monitoring to minimize the risk of potentially toxic levels in cooled newborns.
authors.affiliation: School of Clinical Sciences, University of Bristol, Bristol, United Kingdom; Neonatal Intensive Care Unit, St Michael's Hospital, University Hospitals Bristol, Bristol, United Kingdom.
authors.forename: Elisa
authors.initials: E
authors.lastname: Smit
authors.forename: Xun
authors.initials: X
authors.lastname: Liu
authors.forename: Hannah
authors.initials: H
authors.lastname: Gill
authors.forename: Hemmen
authors.initials: H
authors.lastname: Sabir
authors.forename: Sally
authors.initials: S
authors.lastname: Jary
authors.forename: Marianne
authors.initials: M
authors.lastname: Thoresen
mesh_terms: D001927:Brain Diseases / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D005260:Female; D005839:Gentamicins / Q000097:blood / Q000627:therapeutic use; D034381:Hearing Loss / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007003:Hypoglycemia / Q000175:diagnosis; D007036:Hypothermia, Induced / Q000009:adverse effects*; D020925:Hypoxia-Ischemia, Brain / Q000175:diagnosis / Q000401:mortality; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D015997:Neonatal Screening / Q000379:methods; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D005839:Gentamicins
keywords: AABR; AOAE; Automated auditory brainstem response; Automated otoacoustic emissions; BSID-II; Bayley Scales of Infant Development, Second Edition; MDI; Mental Developmental Index; PDI; Pyschomotor Developmental Index