RESUMO
ABSTRACT INTRODUCTION: Hyperbilirubinemia is a common health problem in newborns. Its effects can be different according to the level and duration of the hyperbilirubinemia. The toxic effect of bilirubin on the auditory system can be seen as a sensory neural hearing loss or auditory neuropathy spectrum disorder (ANSD). OBJECTIVE: The purpose of our study was to determine the effects of toxic bilirubin level on the auditory system by using Auditory Brainstem Response audiometry. METHODS: Rats are used as animal models due to their low cost and easy attainability. Auditory Brainstem Response was used for auditory assessment. In this study, three groups were established: experimental, control and placebo groups. RESULTS: In the experimental group, which consists of rats with hyperbilirubinemia, sensory neural hearing loss was found bilaterally in 4 rats (66.67%) and unilaterally in 2 rats (16.67%) and auditory neuropathy spectrum disorder was found unilaterally in 1 rat (8.33%). Auditory Brainstem Response thresholds were significantly elevated compared to control and placebo groups (p < 0.05). CONCLUSION: Hyperbilirubinemia of newborn rats may result both in sensory neural hearing loss and auditory neuropathy spectrum disorder.
RESUMO INTRODUÇÃO: A hiperbilirrubinemia é um problema de saúde comum em neonatos. Seus efeitos podem variar, dependendo do nível e da duração da hiperbilirrubinemia. O efeito tóxico da bilirrubina no sistema auditivo pode ser observado na forma de deficiência auditiva sensorioneural ou de distúrbio do espectro da neuropatia auditiva. OBJETIVO: A finalidade de nosso estudo foi determinar os efeitos de nível tóxico de bilirrubina no sistema auditivo, com o uso da audiometria da resposta auditiva evocada de tronco cerebral. MÉTODO: Os ratos são empregados como modelos animais graças a seu baixo custo e fácil obtenção. Utilizamos a resposta auditiva evocada de tronco cerebral para avaliação da audição. No estudo, foram estabelecidos três grupos: experimental, controle e placebo. RESULTADOS: No grupo experimental, constituído de ratos com hiperbilirrubinemia, disacusia auditiva neurosensorial foi diagnosticada bilateralmente em quatro ratos (66,67%), e unilateralmente em dois (16,67%); e distúrbio do espectro da neuropatia auditiva foi observado unilateralmente em um rato (8,33%). Os limiares da resposta evocada de tronco cerebral estavam significantemente elevados, em comparação com os grupos controle e placebo (p < 0,05). CONCLUSÃO: A hiperbilirrubinemia de ratos neonatos pode resultar tanto em disacusia auditiva neurosensorial como em distúrbio do espectro da neuropatia auditiva.
Assuntos
Animais , Masculino , Ratos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Potenciais Evocados Auditivos/fisiologia , Perda Auditiva Neurossensorial/fisiopatologia , Hiperbilirrubinemia Neonatal/fisiopatologia , Animais Recém-Nascidos , Audiometria , Modelos Animais de Doenças , Perda Auditiva Neurossensorial/etiologia , Hiperbilirrubinemia Neonatal/complicações , Ratos WistarRESUMO
INTRODUCTION: Hyperbilirubinemia is a common health problem in newborns. Its effects can be different according to the level and duration of the hyperbilirubinemia. The toxic effect of bilirubin on the auditory system can be seen as a sensory neural hearing loss or auditory neuropathy spectrum disorder (ANSD). OBJECTIVE: The purpose of our study was to determine the effects of toxic bilirubin level on the auditory system by using Auditory Brainstem Response audiometry. METHODS: Rats are used as animal models due to their low cost and easy attainability. Auditory Brainstem Response was used for auditory assessment. In this study, three groups were established: experimental, control and placebo groups. RESULTS: In the experimental group, which consists of rats with hyperbilirubinemia, sensory neural hearing loss was found bilaterally in 4 rats (66.67%) and unilaterally in 2 rats (16.67%) and auditory neuropathy spectrum disorder was found unilaterally in 1 rat (8.33%). Auditory Brainstem Response thresholds were significantly elevated compared to control and placebo groups (p<0.05). CONCLUSION: Hyperbilirubinemia of newborn rats may result both in sensory neural hearing loss and auditory neuropathy spectrum disorder.
Assuntos
Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Potenciais Evocados Auditivos/fisiologia , Perda Auditiva Neurossensorial/fisiopatologia , Hiperbilirrubinemia Neonatal/fisiopatologia , Animais , Animais Recém-Nascidos , Audiometria , Modelos Animais de Doenças , Perda Auditiva Neurossensorial/etiologia , Hiperbilirrubinemia Neonatal/complicações , Masculino , Ratos , Ratos WistarRESUMO
OBJECTIVE: To determine the clinical and epidemiological features of infants with extreme hyperbilirubinemia who require exchange transfusion (ET). STUDY DESIGN: Term and near-term infants admitted to a paediatric hospital over a 5-year period in La Paz, Bolivia, were included in the study if they met the following criteria: age less than 30 days; total serum bilirubin (TSB) levels > or =428 micromol/L (> or =25 mg/dL) on admission and if they had undergone an ET. RESULTS: Fifty-six infants were identified during the study period. Most of them were exclusively breastfed (98.2%). Median age at admission was 7 days. Weight loss of more than 12% since birth, as well as dehydration, was registered in more than one-third of cases. Extreme hyperbilirubinemia was considered as secondary to increased enterohepatic circulation (EHC) in most cases (73%). The mean TSB level on admission was 531.8 micromol/L (31.1 mg/dL). Fifteen infants (26.8%) showed signs of acute bilirubin encephalopathy (ABE). Early ABE was reversible after ET in most cases but all infants with advanced ABE developed severe kernicteric sequelae. Nine patients (16.1%) developed adverse events attributable to ET. CONCLUSIONS: Dehydration and weight loss in breastfed infants appeared to be an important factor associated with extreme hyperbilirubinemia and secondary brain damage during the first week of life. This may well be avoided if signs of ABE and its associated conditions are identified appropriately by follow-up programmes.
Assuntos
Bilirrubina/sangue , Transfusão Total , Hiperbilirrubinemia Neonatal/epidemiologia , Hiperbilirrubinemia Neonatal/terapia , Kernicterus/epidemiologia , Bolívia/epidemiologia , Estudos Epidemiológicos , Feminino , Humanos , Hiperbilirrubinemia Neonatal/complicações , Hiperbilirrubinemia Neonatal/fisiopatologia , Lactente , Recém-Nascido , Kernicterus/etiologia , Masculino , Estudos Retrospectivos , Fatores de RiscoRESUMO
UNLABELLED: Auditory brainstem responses (ABR) reveals the neurophysiological status of the neural axis. In this study we compared the ABR of healthy children, under 1-year-old, with children who suffered from perinatal encephalopathy (PE). OBJECTIVE: The purpose of this study was to characterize the ABR differences between children with PE and healthy children in order to identify groups with specific neurophysiological profiles, associated with their neurological condition. METHODS: Thirty-six children with perinatal encephalopathy (PE) and 36 healthy children, ages 1-12 months, were studied. The variables considered were: latencies of waves I, II, N1, III, V, and N2; interpeak latency interval (IPL) of waves I-III, III-V, and I-V; as well as amplitudes of waves I, III, and V. The results were analyzed using ANOVA, as well as Ji(2), and Ward's cluster analysis. RESULTS: The absolute latencies of the ABR showed an inverse correlation with the children's age. Latencies of waves I, II, N1, V, and N2, IPL III-V, and amplitude of waves III and V show significant differences (p<0.05) between healthy and PE children. Children with PE showed greater absolute latencies and larger wave amplitudes than the control group. Ward's cluster analysis, used to define the groups with similar functional characteristics, revealed three groups: fast, intermediate, and slow-responders, depending on their wave latencies and IPL wave amplitudes. These groups were gender- (p<0.03), age- (p<0.0001), and neurological damage- (p<0.01) related. CONCLUSIONS: Our data clearly show that the ABR obtained from PE children differ from ABR obtained from healthy children. PE infants showed larger wave latencies, intervals amplitudes than the control group. Three functional profiles resulted from the groups established using the Ward's method, and these indicate their neurological functional condition.