Risk Factors for Sensorineural Hearing Loss Among High-Risk Infants in Golestan Province, Iran in 2010 - 2011

Individualized vancomycin dosing in infants: prospective evaluation of an online dose calculator

BACKGROUND

Empiric vancomycin dosing regimens fail to achieve recommended target trough concentrations of 10-20 mg/L in the majority of infants. This study assessed the performance of a model-based dosing calculator (Vanc App) in achieving target vancomycin concentrations at first steady-state level.

METHODS

This was a multicenter prospective study in four tertiary pediatric hospitals over an 18-month period. Infants aged 0-90 days with suspected Gram-positive sepsis requiring empiric vancomycin treatment were included if they did not meet any of the exclusion criteria: post-menstrual age (PMA) <25 weeks, weight <500 g, glycopeptide allergy, receiving extracorporeal membrane oxygenation, vancomycin use within the previous 72 h, and renal impairment. The Vanc App used a published population pharmacokinetic model to generate a dose based on the infant's PMA, weight, creatinine, and target vancomycin concentration.

RESULTS

A total of 40 infants were included; 40% were female, median (range) weight was 2505 (700-4460) g and median (range) PMA was 37.4 (25.7-49.0) weeks. The median (range) vancomycin dose was 45 (24-79) mg/kg/day. All infants had trough vancomycin concentrations measured at steady-state (24-<48 hours) and 30 (75%) infants achieved target concentrations. Five infants had supratherapeutic (median 25, range 21-38 mg/L) and five had subtherapeutic (median 6, range <5-9 mg/L) concentrations. An area under the concentration-time curve (AUC_0-24) of 400-650 mg/L.h was achieved in 33 (83%) infants. There were no infusion-related reactions or nephrotoxicity.

CONCLUSION

Individualized intermittent vancomycin dosing using a model-based online calculator resulted in 75% and 83% of infants achieving target trough and AUC_0-24, respectively, at first steady-state level. There were no vancomycin-related nephrotoxicity or infusion-related reactions.

Vancomycin-induced ototoxicity in very-low-birthweight infants

BACKGROUND

Vancomycin is an extensively used anti-infective drug in neonatal ICUs. However, exposure-toxicity relationships have not been clearly defined.

OBJECTIVES

To evaluate the risk profile for hearing deficits in vancomycin-exposed very-low-birthweight infants (VLBWI).

METHODS

In a large cohort study of the German Neonatal Network (GNN; n = 16 967 VLBWI) we assessed the association of vancomycin treatment and pathological hearing tests at discharge and at 5 year follow-up. We performed audits on vancomycin exposure, drug levels, dose adjustments and exposure to other ototoxic drugs in a subgroup of 1042 vancomycin-treated VLBWI.

RESULTS

In the GNN cohort, 28% (n = 4739) were exposed to IV vancomycin therapy. In multivariable logistic regression analysis, vancomycin exposure proved to be independently associated with pathological hearing test at discharge (OR 1.18, 95% CI 1.03-1.34, P = 0.016). Among vancomycin-treated infants, a cumulative vancomycin dose above the upper quartile (>314 mg/kg bodyweight) was associated with pathological hearing test at discharge (OR 2.1, 95% CI 1.21-3.64, P = 0.009), whereas a vancomycin cumulative dose below the upper quartile was associated with a reduced risk of pathological tone audiometry results at 5 years of age (OR 0.29, 95% CI 0.1-0.8, P = 0.02, n = 147).

CONCLUSIONS

Vancomycin exposure in VLBWI is associated with an increased, dose-dependent risk of pathological hearing test results at discharge and at 5 years of age. Prospective studies on long-term hearing impairment are needed.

Prevalence and Risk Factors for Hearing Loss in Neonates Admitted to the Neonatal Intensive Care Unit: A Hospital Study

INTRODUCTION

Hearing loss is one of the most common congenital disabilities in neonates. The aims of this study were to investigate the prevalence of hearing loss and identify the most significant risk factor in neonates hospitalized at the Neonatal Intensive Care Unit (NICU).

METHODS

This cross-sectional study involved 530 neonates admitted to NICU Abuzar Hospital with risk factors for hearing loss based on Joint Committee of Infant Hearing (JCIH). The hearing screening tests include transient evoked otoacoustic emissions (TEOAES) and the automated auditory brain stem response (AABR). For infants with abnormal AABR and TEOAE results, the Auditory Brainstem Response (ABR) and Auditory Steady-State Responses (ASSR) tests were performed.

RESULT

Of 530 infants, 27 (5.09%) were diagnosed with different types of hearing loss. Ototoxic drugs, hyperbilirubinemia requiring exchange transfusion, asphyxia, low weight birth, Apgar score < 5, and a kinship marriage of parents were significant risk factors for hearing loss in our study population.

CONCLUSION

Due to the high prevalence of hearing loss in the NICU, it is recommended that a hearing screening program be performed for all infants admitted to the NICU. Implement a comprehensive plan for neonatal hearing screening for early detection and intervention of hearing loss is essential.

Prevalence of Hearing Impairment Among High-Risk Newborns in Ibadan, Nigeria

The burden of severe hearing impairment is increasing with two-thirds of these hearing impaired people residing in developing countries. Newborn hearing screening helps to identify early, babies who need intervention in order to prevent future disability. Neither universal nor targeted hearing screening programme is available in Nigeria. Objectives: This study was carried out to assess the prevalence of hearing impairment among high-risk newborns in UCH and the associated risk factors. Materials and Methods: Two hundred one newborns in the neonatal unit of UCH with risk factors for hearing impairment had hearing screening done using automated auditory brainstem response (AABR) at 30, 45, and 70 dB at admission and discharge, and those that failed screening at discharge were rescreened at 6 weeks post-discharge. Results: Eighty-three (41.3%) and 32 (15.9%) high-risk newborns failed at admission and discharge screening respectively, and 19 (9.5%) still failed at follow up screening. The majority of hearing loss at follow up was bilateral (94.7%) and severe (52.6%). The risk factors associated with persistent hearing loss at follow up were acute bilirubin encephalopathy (RR = 11.2, CI: 1.4-90.6), IVH (RR = 8.8, CI: 1.1-71.8), meningitis (RR = 4.8, CI: 1.01-29), recurrent apnoea (RR = 2.7, CI: 1.01-7.3), severe perinatal asphyxia NNE III (RR = 7, CI: 2.4-20.2). Conclusion: Severe and bilateral hearing impairment is a common complication among high risk newborns in UCH persisting till 6 weeks post-neonatal care. Severe perinatal asphyxia with NNE III, ABE, IVH, meningitis and administration of amikacin for more than 5 days were significant risk factors. We recommend that SCBU graduates with these risk factors should have mandatory audiologic evaluation at discharge.

Prevalence and independent risk factors for hearing impairment among very low birth weight infants

BACKGROUND

Although we've made big strides in perinatal and neonatal care, auditory handicap remains a serious complication in those who were born very premature.

OBJECTIVES

The aim was to determine the prevalence and analyze possible risk factors of hearing impairment in very-low-birth-weight (VLBW) infants.

MATERIALS AND METHODS

This was a retrospective study by reviewing medical records of all VLBW infants (BW ≤ 1500 g) admitted to NICU of Chang Gung Children's Hospital over 2 years period from Jan. 2010 to 2011. Brainstem auditory evoked potentials (BAEP) hearing screening was performed at 3 months postnatal corrective age and repeated if failed the 1st time, then refer to ENT doctor if BAEP confirmed abnormal. All VLBW infants examined for hearing impairment were included and data were retrieved retrospectively and analyzed for neonatal risk factors using logistic regression.

RESULTS

Over the period, 309 VLBW infants were screened. Prevalence of uni- or bilateral hearing impairment was 3.9% (12/309; 95% CI 2.6-4.1). The mean corrective age on diagnosed of hearing impairment was 2.9 ± 1.1 (range 1-5) months. Mean gestational age was 27.9 weeks (SD 1.4) and mean birth weight was 1028 g (SD 180). By univariant analysis for hearing impairment, severe birth asphyxia, craniofacial anomalies, ventilator dependence, patent ductus arteriosus ligation, and use of postnatal ototoxins yielded good prediction of hearing impairment in this population. However, using multivariate analysis revealed that the only independent risk factors for hearing impairment were ototoxins (OR: 3.62; CI: 1.67-7.82), PDA ligation (OR: 4.96; CI: 2.34-10.52), craniofacial anomalies (OR: 3.42; CI: 1.70-6.88)and assisted prolonged use of oxygen at gestational age of >36 weeks (OR: 5.94; CI: 2.61-13.54).

CONCLUSION

The incidence of hearing impairment among VLBW infants was 3.9%. Prolonged supplemental oxygen use is a marker for predicting hearing impairment; this requires detailed analysis of the pathophysiologic features, to reduce the prevalence of hearing impairment.