Gentamicin Exposure and Sensorineural Hearing Loss in Preterm Infants

Pharmacogenetics of aminoglycoside-related ototoxicity: a systematic review

BACKGROUND

Aminoglycosides (AGs) are important antibiotics in the treatment of Gram-negative sepsis. However, they are associated with the risk of irreversible sensorineural hearing loss (SNHL). Several genetic variants have been implicated in the development of ototoxicity.

OBJECTIVES

To evaluate the pharmacogenetic determinants of AG-related ototoxicity.

METHODS

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses and was registered on Prospero (CRD42022337769). In Dec 2022, PubMed, Cochrane Library, Embase and MEDLINE were searched. Included studies were those reporting original data on the effect of the AG-exposed patient's genome on the development of ototoxicity.

RESULTS

Of 10 202 studies, 31 met the inclusion criteria. Twenty-nine studies focused on the mitochondrial genome, while two studied the nuclear genome. One study of neonates found that 30% of those with the m.1555A > G variant failed hearing screening after AG exposure (level 2 evidence). Seventeen additional studies found the m.1555A > G variant was associated with high penetrance (up to 100%) of SNHL after AG exposure (level 3-4 evidence). Nine studies of m.1494C > T found the penetrance of AG-related SNHL to be up to 40%; however, this variant was also identified in those with SNHL without AG exposure (level 3-4 evidence). The variants m.1005T > C and m.1095T > C may be associated with AG-related SNHL; however, further studies are needed.

CONCLUSIONS

This review found that the m.1555A > G and m.1494C > T variants in the MT-RNR1 gene have the strongest evidence in the development of AG-related SNHL, although study quality was limited (level 2-4). These variants were associated with high penetrance of a SNHL phenotype following AG exposure.

Geographical distribution of antimicrobial exposure among very preterm and very low birth weight infants: A nationwide database study in Japan

OBJECTIVES

To examine spatial effects in neonatal care, we conducted a retrospective cohort study to investigate the geographical distribution of antimicrobial exposure among very preterm and very low birth weight infants in Japan.

STUDY DESIGN

We utilized a nationwide claims database in Japan to extract prescriptions of injectable antimicrobials for 41,423 very preterm and very low birth weight infants admitted within the first two days of life from April 2010 to March 2021. We identified frequently prescribed antimicrobials, revealed early neonatal exposure and neonatal exposure to each antimicrobial agent by 47 prefectures in Japan, and evaluated their spatial autocorrelation using global and local Moran's I statistics. We then scrutinized regional disparities in antimicrobial drug prescriptions.

RESULTS

The top 10 antimicrobials prescribed to very preterm and very low birth weight infants in Japan were ampicillin, amikacin, gentamicin, cefotaxime, fluconazole, ampicillin combination, micafungin, cefmetazole, cefazolin, and vancomycin. We identified northern cold spots for fluconazole exposure and southern hot spots for ampicillin, amikacin, gentamicin, and cefmetazole exposure. Geographical heterogeneity in the selection of antibacterial and antimycotic agents was observed.

CONCLUSION

Our study revealed the geographical distribution of antimicrobial exposure among very preterm and very low birth weight infants in Japan, thus disclosing its spatial effects. Further research addressing the spatial effects of neonatal care is needed to understand how drug exposure affects the outcomes of preterm infants.

Exploring NICU nurses' views of a novel genetic point-of-care test identifying neonates at risk of antibiotic-induced ototoxicity: A qualitative study

AIM

To explore the views of neonatal intensive care nursing staff on the deliverability of a novel genetic point-of-care test detecting a genetic variant associated with antibiotic-induced ototoxicity.

DESIGN

An interpretive, descriptive, qualitative interview study.

METHODS

Data were collected using semi-structured interviews undertaken between January and November 2020. Participants were neonatal intensive care nursing staff taking part in the Pharmacogenetics to Avoid Loss of Hearing trial.

RESULTS

Thematic analysis resulted in four themes: perceived clinical utility; the golden hour; point-of-care device; training and support. Recommendations were made to streamline the protocol and ongoing training and support were considered key to incorporating the test into routine care.

CONCLUSION

Exploring the views of nurses involved in the delivery of the point-of-care test was essential in its implementation. By the study endpoint, all participants could see the value of routine clinical introduction of the point-of care test.

IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE

Nurses are in a key position to support the delivery of point-of-care genetic testing into mainstream settings. This study has implications for the successful integration of other genetic point-of-care tests in acute healthcare settings.

IMPACT

The study will help to tailor the training and support required for routine deployment of the genetic point-of-care test. The study has relevance for nurses involved in the development and delivery of genetic point-of-care tests in other acute hospital settings.

REPORTING METHOD

This qualitative study adheres to the Standards for Reporting Qualitative Research EQUATOR guidelines and utilizes COREQ and SRQR checklists.

PATIENT OR PUBLIC CONTRIBUTION

All staff working on the participating neonatal intensive care units were trained to use the genetic point-of-care test. All inpatients on the participating units were eligible to have testing via the point-of-care test. The Pharmacogenetics to Avoid Loss of Hearing Patient and Public Involvement and Engagement group provided valuable feedback.

TRIAL AND PROTOCOL REGISTRATION

Registered within the University of Manchester. Ethics approval reference numbers: IRAS: 253102 REC reference: 19/NW/0400. Also registered with the ISRCTN ref: ISRCTN13704894.

Assessment of gentamicin dosing and monitoring in neonates: A single center experience

BACKGROUND

Gentamicin is a commonly used medication in NICUs. It is known to have ototoxic & nephrotoxic side effects. To date there is no consensus about dosing regimen in different institutions. Our study aims to evaluate the Neofax® dosing regimen for gentamicin in neonatal early onset sepsis in relation to trough level before the second dose and its association with the incidence of gentamicin side effects, namely hearing impairment/loss and acute kidney injury.

METHODS

Retrospective chart review of newborns admitted to Tawam hospital NICU (June 2019-May 2020) who received gentamicin for early onset sepsis (≤72 hours old). Trough levels before the second dose at 24,36 and 48 hours were reviewed (≥1 mg/L is high). Excluded patients with renal risk factors. Side effects (hearing impairment, acute renal injury) were also assessed.

RESULTS

Total of 265 infants were included, among whom 149 patients received gentamicin at 24 hours interval, 99 at 36 and 17 at 48 hours interval. Trough level was high in 76% (P = 0.022), 65% (P = 0.127), and 53% (P = 0.108) of patients who received gentamicin at 24, 36, and 48 hours, respectively. Hearing screening was normal in 99.2% of patients, while 2 patients failed the test (Both with normal trough levels). No patients in our study developed renal injury related to gentamicin use.

CONCLUSION

Neofax® gentamicin dosing often results in high trough levels, especially in late preterm/term infants. This study found no correlation between high trough levels and hearing impairment upon discharge or acute kidney injury. Further studies with larger sample size are recommended.

Cumulative risk factors contributing to hearing loss in preterm infants

OBJECTIVE

To investigate individual and concomitant risk factors for hearing loss during neonatal care.

DESIGN

Case-control study.

SETTING

Community.

POPULATION

237 children born <32 weeks of gestation; 57 with hearing loss and 180 with normal hearing born between 2009 and 2013, matched for sex, gestation and year of birth.

MAIN OUTCOME MEASURES

Data were abstracted from clinical records for overall risk factors daily for the first 14 days and then weekly until discharge from neonatal care. All infants were screened for the presence of m.1555A>G mutation.

RESULTS

Children with hearing loss had lower birth weight for gestational age, more severe neonatal illness, with increased exposure to inotrope, steroid, gentamicin, vancomycin and furosemide, and more frequent physiological risk, elevated bilirubin and creatinine levels and acidosis, but no index child was found to have the m.1555A>G mutation, compared with one among controls. The duration of gentamicin, vancomycin or furosemide administration in the first 14 days was associated with impaired hearing (OR per dose: 1.25; 95% CI 1.14 to 1.38). Multivariate analyses revealed independent risks for hearing loss for each day when there was physiological risk (OR per day 1.15 (1.05 to 1.27)) and each day of medication exposure (OR 1.23 (1.1 to 1.37)).

CONCLUSION

Although the relative contribution of underlying illness and medication cannot be identified by this study, cumulative use of ototoxic medication and the presence of physiologic risk factors independently increased the likelihood of hearing loss, warranting close monitoring of coincident therapy throughout neonatal critical care.

Transdermal patches based on chitosan/hydroxypropyl methylcellulose and polyvinylpyrrolidone/hydroxypropyl methylcellulose polymer blends for gentamycin administration

Biofilm-forming bacteria have sent alarms to the world about the emerging of bacterial resistance. Gentamycin is an aminoglycoside broad-spectrum antibiotic used against microbial infections. The transdermal drug delivery method is a major system used to reduce drug toxicity and avoid first-pass metabolism. Gentamycin was formulated in a transdermal polymeric formula using hydroxypropyl methylcellulose (HPMC), polyvinylpyrrolidone (PVP), and Chitosan in the presence of palmitic acid as a permeation enhancer. In this research, gentamycin extended drug release behavior was successfully done in different polymeric formulas containing (HPMC/PVP) and (HPMC/Chitosan), with a maximum drug release of <70%. In addition, drug diffusion was found to be dependent on the rate of drug release. The controlled release formulas selected for antimicrobial assay show that HPMC/Chitosan formulas have successfully inhibited microbial and biofilm growth by 90%. In conclusion, gentamycin can be formulated in a transdermal polymeric film to target skin infection, reduce drug side effects and avoid drug first-pass metabolism.

Risk patterns associated with transient hearing impairment and permanent hearing loss in infants born very preterm: A retrospective study

AIM

To determine the risk patterns associated with transient hearing impairment (THI) and permanent hearing loss (PHL) of infants born very preterm who failed hearing screenings.

METHOD

We enrolled 646 infants (347 males, 299 females) born at no more than 30 weeks' gestation between 2006 and 2020 who received auditory brainstem response screening at term-equivalent age. Audiological examinations of infants who failed the screening revealed THI, when hearing normalized, or PHL, defined as a persistent unilateral or bilateral hearing threshold above 20 dB. Principal component analysis (PCA) was used to characterize risk patterns.

RESULTS

Among the 646 infants, 584 (90.4%) had normal hearing, 42 (6.5%) had THI, and 20 (3.1%) had PHL. Compared with the group with normal hearing, the THI and PHL groups had significantly higher rates of neurodevelopmental impairment at 24 months corrected age. PCA of risk patterns showed the THI group and especially the PHL group had more severe haemodynamic and respiratory instability. Moreover, severe intraventricular haemorrhage (IVH) was also a risk for PHL. Propensity score matching revealed an association of haemodynamic and respiratory instability with PHL.

INTERPRETATION

In infants born preterm, the severity and duration of haemodynamic and respiratory instability are risk patterns for both THI and PHL; severe IVH is an additional risk for PHL.

WHAT THIS PAPER ADDS

Neurodevelopmental delay was more common in infants born preterm who failed hearing screening. Principal component analysis revealed the risk patterns associated with hearing impairment. Haemodynamic-respiratory instability was associated with transient and permanent hearing impairment outcomes. Severe haemodynamic-respiratory instability and intraventricular haemorrhage was associated with permanent hearing loss.

Early Neurodevelopmental Outcomes after Previable Preterm Prelabour Rupture of Membranes (pPPROM)

Objective

To describe the early neurodevelopmental outcomes following fetal exposure to previable preterm prelabour rupture of membranes (pPPROM).

Methods

This was a secondary analysis of a subgroup of neonates born following pPPROM from a retrospective cohort study (2009–2015). Surviving infants who underwent standardized neurodevelopmental evaluation at 18–24 months corrected age (CA) between 2017 and 2019 were eligible for inclusion. Data abstracted from hospital charts were linked to prospectively collected developmental outcomes stored in an electronic database from a regional neonatal follow-up clinic. The primary outcome was Bayley-III composite scores (compared to the population mean 100, standard deviation (SD) 15). Secondary outcomes included presence of cerebral palsy, vision loss, hearing impairment, and requirement of rehabilitation therapy. Descriptive statistics were used to present results.

Results

25.7% (19/74) of neonates born after pPPROM survived to hospital discharge, but only 21.6% (16/74) survived to 18–24 months CA. Of these, 9 infants were eligible for follow-up at the regional clinic and 7 had developmental outcomes stored in the electronic database. Infants exposed to pPPROM exhibited Bayley-III scores more than 1 SD below the population mean across all three domains: cognitive 84.9 (SD 12.2); motor 82.3 (SD 11.5); and language 66.4 (SD 18.9). There were particular deficiencies in language development with 71% (5/7) scoring more than 2 SDs below the population mean. There were no cases of cerebral palsy.

Conclusions

Only 1 in 5 infants born following expectantly managed pPPROM survived to 18–24 months CA. These infants born after pPPROM had significantly lower Bayley-III scores and particular deficiencies in language development. Better understanding of early neurodevelopmental challenges following pPPROM will help refine counselling of families contemplating expectant management and provide insights into the postnatal educational resources required to improve long-term developmental outcomes for these children.

Change to Hearing Loss-Related Risks and Screening in Preterm Infants

Hearing loss is one of the most common congenital defects in infancy; it increases speech and language delays and adversely affects academic achievement and socialemotional development. The risk of hearing loss in premature infants is higher than that in normal newborns, and because of the fragility of the auditory nervous system, it is more vulnerable to different risk factors. The hearing screening guidelines in current use were proposed by the American Academy of Pediatrics and updated in 2007, but there are no uniform guidelines for hearing screening in preterm infants. This review focuses on the risk factors related to hearing loss in premature infants, hearing screening strategies, and reasons for failure. The aim is to provide a more comprehensive understanding of hearing development in preterm infants to achieve early detection and early intervention. At the same time, attention should be paid to delayed auditory maturation in preterm infants to avoid excessive intervention. KEY POINTS: · Hearing loss is very common in infancy, especially in premature infants.. · Genetic factors, infection, hyperbilirubinemia, drugs, and noise are the main causes.. · We should pay attention to the delayed hearing maturity of premature infants and avoid excessive intervention..

Relationship between gentamicin administration and ductal patency in very low birth weight infants

Background:

Patent ductus arteriosus (PDA) is associated with adverse clinical outcomes in very low birth weight (<1500g) infants.

Objective:

In our study, it was aimed to investigate the effect of gentamicin treatment, which is frequently used for early-onset sepsis on ductal patency.

Method:

We performed a single-center retrospective review of charts of preterm infants <32 weeks gestation with birth weight <1500 grams born between June 1, 2015, and December 31, 2019, at the neonatal intensive care unit. All infants underwent an echocardiogram (ECHO) at 72 hours. To determine the effect of gentamicin treatment on hemodynamically significant PDA (hsPDA), we compared the frequency and duration of gentamicin administration between infants with hsPDA and without hsPDA.

Results:

During the study period, 792 patients were evaluated. Gentamicin was given to more infants with hsPDA than to those without hsPDA (89.2 % vs. 64.6 %, p<0.001), and the duration of therapy was longer in those infants with hsPDA (7 days vs. 9 days, p<0.001). The area under the curve for duration of gentamicin was 0.772 (%95 CI: 0.742-0.804, P=0.0001), sensitivity: 59 (%95 CI: 53-65), specificity: 82 (%95 CI: 78-88), with a cut-off day for duration of gentamicin >7 days.

Conclusion:

In our study, it was found that ductal contraction decreased and hsPDA rate increased as the rate and duration of gentamicin increased.

Extended high frequency audiometry thresholds in healthy school children

OBJECTIVES

Extended high frequency (EHF) audiometry is the recommended method for monitoring oxotoxic hearing loss in children. This study aims to provide high quality reference audiological data for the EHF range in healthy children.

METHODS

Participants were 126 healthy schoolchildren between 6 and 14 years of age. All participants were term born with normal birthweight, had not suffered severe neonatal illness and had no history of middle ear disease.

RESULTS

The averaged mean (SD) hearing threshold for the EHF 9, 10, 11.2, 12.5, 14 and 16 kHz was -0.4 (6.0) dB HL. The lowest mean hearing thresholds were observed at 14 kHz with -4.2 (8.7) dB and at 16 kHz with -6.4 (12.1) dB HL. We found significantly lower thresholds at 16 kHz for children aged 6-9 years (-8.7 dB HL) compared to age 10-14 years (-3.9 db HL), p 0.042. For both age groups the inter-subject variability increased in the highest frequencies. We found no significant differences in mean hearing thresholds between right and left ears at any frequency, and no gender differences in the EHF range.

CONCLUSION

Our findings support that decreased hearing sensitivity in the EHF's may start around or even before the age of 10 years. In order to use EHF audiometry for ototoxic monitoring in children, we suggest to establish an international reference standard for hearing levels in children under the age of 18. Specific references for different age groups are needed as hearing in the EHF range appears to gradually deteriorate from an early age.

CLINICAL TRIAL REGISTRATION

NCT03253614.

Hearing screening in neonates with hyperbilirubinemia

BACKGROUND

Hyperbilirubinemia is toxic to the auditory pathways and to the central nervous system, leaving sequelae such as hearing loss and encephalopathy. The damage to the auditory system occurs primarily within the brainstem and cranial nerve VIII, and manifests clinically as auditory neuropathy spectrum disorder.

AIM

to establish the relationship that exists between hyperbilirubinemia at birth as a risk factor of neonatal hearing loss in children born in ABOU-EL-REISH hospital.

MATERIALS AND METHODS

we carried out of 60 neonates categorized into two groups: Group (A n = 30), neonates with hyperbilirubinemia; Group (B n = 30), neonates without hyperbilirubinemia.

RESULTS

Ten neonates were boys and twenty were girls from group A and eleven boys and nigh-teen girls from group B.There was significant statistical difference between group A and group B regarding ABR (P-value = 0.001) and a statistical difference regarding OAE (P-value = 0.103 in the right ear and 0.028 in the left ear). Also, our study shows the area under the curve and the diagnostic accuracy of total serum bilirubin (TSB) level for detection of hearing screening results (ABR) at a cut-off point 21 mg/dl (P-value = 0.008 and 0.009 in the right and left ears respectively.) CONCLUSIONS: Our study showed a relevant association between bilirubin levels and abnormal hearing screening results and the importance of combined screening with OAE and ABR tests.

Changes in auditory function in premature children: A prospective cohort study

OBJECTIVES

To analyze the age-specific pattern of auditory function in preterm children as a function of their gestational age at birth.

STUDY DESIGN

longitudinal cohort study.

METHODS

a prospective cohort study involved 271 preterm children aged from 6 months to 15 years old. Children were divided into two groups: 70 children with a gestational age at birth of 32-36 weeks (Group 1) and 201 children with a gestational age of 22-31 weeks (Group 2). Hearing was assessed by ABR, ASSR, OAE, behavioral audiometry, and pure tone audiometry. Additionally, for some children, CT, MRI, and GBJ2 evaluations were performed. Assessments of hearing impaired children were performed 3-4 times a year for children under 2 years of age; 2-3 times a year for children from 2 to 5 years of age; and 1-2 times a year for children over 5 years of age. Infants without any hearing problems were examined 2-3 times during their first year of life, followed by annual examinations as they aged.

RESULTS

The initial hearing examination identified SNHL and ANSD in 18 children (25.7%) and 64 children (31.8%) in Group 1 and Group 2, respectively. No significant difference in the occurrence of auditory impairment in the two groups was found at the initial assessment (p > 0.05). Further long-term follow-up revealed changes in hearing in 16 children: 15 from Group 2 and only one child from Group 1. Four different kinds of hearing changes were noted: hearing recovery to normal levels in children with ANSD; late onset hearing loss; the transformation of ANSD to SNHL, and vice versa. The age, factors, and possible mechanisms of such changes are discussed in the article.

CONCLUSION

The auditory function in prematurely born children tends to be unstable, especially at a very early age. In very preterm infants, it may either deteriorate or improve. Infants born before 31 weeks' gestation require long-term follow-up at least until they are 3-4 years of age. Caution is advised regarding very early cochlear implantation for children born before 32 weeks of gestation age.

Toll-like Receptor 4 Signaling and Downstream Neutrophilic Inflammation Mediate Endotoxemia-Enhanced Blood-Labyrinth Barrier Trafficking

HYPOTHESIS

Both toll-like receptor 4 (TLR4) and downstream neutrophil activity are required for endotoxemia-enhanced blood-labyrinth barrier (BLB) trafficking.

BACKGROUND

Aminoglycoside and cisplatin are valuable clinical therapies; however, these drugs often cause life-long hearing loss. Endotoxemia enhances the ototoxicity of aminoglycosides and cisplatin in a TLR4 dependent mechanism for which downstream proinflammatory signaling orchestrates effector immune cells including neutrophils. Neutrophil-mediated vascular injury (NMVI) can enhance molecular trafficking across endothelial barriers and may contribute to endotoxemia-enhanced drug-induced ototoxicity.

METHODS

Lipopolysaccharide (LPS) hypo-responsive TLR4-KO mice and congenitally neutropenic granulocyte colony-stimulating factor (GCSF) GCSF-KO mice were studied to investigate the relative contributions of TLR4 signaling and downstream neutrophil activity to endotoxemia-enhanced BLB trafficking. C57Bl/6 wild-type mice were used as a positive control. Mice were treated with LPS and 24 hours later cochleae were analyzed for gene transcription of innate inflammatory cytokine/chemokine signaling molecules, neutrophil recruitment, and vascular trafficking of the paracellular tracer biocytin-TMR.

RESULTS

Cochlear transcription of innate proinflammatory cytokines/chemokines was increased in endotoxemic C57Bl/6 and GCSF-KO, but not in TLR4-KO mice. More neutrophils were recruited to endotoxemic C57Bl/6 cochleae compared with both TLR4 and GCSF-KO cochleae. Endotoxemia enhanced BLB trafficking of biocytin-TMR in endotoxemic C57Bl/6 cochleae and this was attenuated in both TLR4 and GCSF-KO mice.

CONCLUSION

Together these results suggest that TLR4-mediated innate immunity cytokine/chemokine signaling alone is not sufficient for endotoxemia-enhanced trafficking of biocytin-TMR and that downstream neutrophil activity is required to enhance BLB trafficking. Clinically, targeting neutrophilic inflammation could protect hearing during aminoglycoside, cisplatin, or other ototoxic drug therapies.

Hearing in Schoolchildren After Neonatal Exposure to a High-Dose Gentamicin Regimen

OBJECTIVE

To assess the association between gentamicin exposure in the neonatal period and hearing in school age.

METHODS

This study included children exposed to a high-dose (6 mg/kg) gentamicin regimen as neonates (2004-2012), invited for follow-up at school age, and a healthy age-matched control group. We assessed hearing with pure tone audiometry including the extended high-frequency (EHF) range. Outcomes were average hearing thresholds in the midfrequencies (0.5-4 kHz) and the EHFs (9-16 kHz). The measures of gentamicin exposure were cumulative dose and highest trough plasma concentration. We used linear regression models to assess the impact of gentamicin exposure, and other peri- and postnatal morbidities, on hearing thresholds.

RESULTS

A total of 219 gentamicin-exposed and 33 healthy-control children were included in the audiological analysis. In the gentamicin cohort, 39 (17%) had a birth weight <1500 g. Median cumulative doses and trough plasma concentrations were 30 (interquartile range 24-42) mg/kg and 1.0 (interquartile range 0.7-1.2) mg/L, respectively. Median hearing thresholds for the midfrequencies and the EHFs were 2.5 (0 to 6.3) dB hearing level and -1.7 (-5.0 to 5.0) dB hearing level, both of which were within the normal range. In an adjusted analysis, increasing hearing thresholds were associated with lower birth weight and postnatal middle-ear disease but not level of gentamicin exposure. After adjusting for birth weight, there was no difference in hearing threshold between the gentamicin-exposed cohort and healthy controls.

CONCLUSIONS

Exposure to a high-dose gentamicin regimen in the neonatal period was not associated with an increase in hearing thresholds in schoolchildren being able to complete audiometry.

Early onset sepsis calculator-based management of newborns exposed to maternal intrapartum fever: a cost benefit analysis

OBJECTIVE

To determine potential net monetary benefit of an early onset sepsis calculator-based approach for management of neonates exposed to maternal intrapartum fever, compared to existing guidelines.

STUDY DESIGN

We performed a cost-benefit analysis comparing two management approaches for newborns >34 weeks gestational age exposed to maternal intrapartum fever. Probabilities of sepsis and meningitis, consequences of infection and antibiotic use, direct medical costs, and indirect costs for long-term disability and mortality were considered.

RESULTS

A calculator-based approach resulted in a net monetary benefit of $3998 per infant with a 60% likelihood of net benefit in probabilistic sensitivity analysis. Our model predicted a 67% decrease in antibiotic use in the calculator arm. The absolute difference for all adverse clinical outcomes between approaches was ≤0.6%.

CONCLUSIONS

Compared to existing guidelines, a calculator-based approach for newborns exposed to maternal intrapartum fever yields a robust net monetary benefit, largely by preventing unnecessary antibiotic treatment.

Evaluation of Gentamicin Exposure in the Neonatal Intensive Care Unit and Hearing Function at Discharge

OBJECTIVE

To characterize the association between gentamicin dosing, duration of treatment, and ototoxicity in hospitalized infants.

STUDY DESIGN

This retrospective cohort study conducted at 330 neonatal intensive care units (2002-2014) included inborn infants exposed to gentamicin with available hearing screen results, and excluded infants with incomplete dosing data and major congenital anomalies. Our primary outcome was the final hearing screen result performed during hospitalization: abnormal (failed or referred for further testing in one or both ears) or normal (bilateral passed). The 4 measures of gentamicin exposure were highest daily dose, average daily dose, cumulative dose, and cumulative duration of exposure. We fitted separate multivariable logistic regression models adjusted for demographics, comorbidities, and other clinical events.

RESULTS

A total of 84 808 infants met inclusion/exclusion criteria; median (25th, 75th percentile) gestational age and birth weight were 35 weeks (33, 38) and 2480 g (1890, 3184), respectively. Failed hearing screens occurred in 3238 (3.8%) infants; failed screens were more likely in infants of lower gestational age and birth weight, who had longer hospital lengths of stay, higher rates of morbidities, and were small for gestational age. Median highest daily dose, average daily dose, and cumulative dose were 4.0 mg/kg/day (3.0, 4.0), 3.8 mg/kg/day (3.0, 4.0), and 12.1 mg/kg (9.1, 20.5), respectively. Median cumulative duration of exposure was 3 days (3, 6). In adjusted analysis, gentamicin dose and duration of therapy were not associated with hearing screen failure.

CONCLUSIONS

Gentamicin dosing and duration of treatment were not associated with increased odds of failed hearing screen at the time of discharge from initial neonatal intensive care unit stay.

Using machine learning to guide targeted and locally-tailored empiric antibiotic prescribing in a children's hospital in Cambodia

Background: Early and appropriate empiric antibiotic treatment of patients suspected of having sepsis is associated with reduced mortality. The increasing prevalence of antimicrobial resistance reduces the efficacy of empiric therapy guidelines derived from population data. This problem is particularly severe for children in developing country settings. We hypothesized that by applying machine learning approaches to readily collect patient data, it would be possible to obtain individualized predictions for targeted empiric antibiotic choices. Methods and Findings: We analysed blood culture data collected from a 100-bed children's hospital in North-West Cambodia between February 2013 and January 2016. Clinical, demographic and living condition information was captured with 35 independent variables. Using these variables, we used a suite of machine learning algorithms to predict Gram stains and whether bacterial pathogens could be treated with common empiric antibiotic regimens: i) ampicillin and gentamicin; ii) ceftriaxone; iii) none of the above. 243 patients with bloodstream infections were available for analysis. We found that the random forest method had the best predictive performance overall as assessed by the area under the receiver operating characteristic curve (AUC). The random forest method gave an AUC of 0.80 (95%CI 0.66-0.94) for predicting susceptibility to ceftriaxone, 0.74 (0.59-0.89) for susceptibility to ampicillin and gentamicin, 0.85 (0.70-1.00) for susceptibility to neither, and 0.71 (0.57-0.86) for Gram stain result. Most important variables for predicting susceptibility were time from admission to blood culture, patient age, hospital versus community-acquired infection, and age-adjusted weight score. Conclusions: Applying machine learning algorithms to patient data that are readily available even in resource-limited hospital settings can provide highly informative predictions on antibiotic susceptibilities to guide appropriate empiric antibiotic therapy. When used as a decision support tool, such approaches have the potential to improve targeting of empiric therapy, patient outcomes and reduce the burden of antimicrobial resistance.

Inflammatory and Immune Proteins in Umbilical Cord Blood: Association with Hearing Screening Test Failure in Preterm Neonates

Objective

We aimed to determine whether elevated levels of various inflammatory and immune proteins in umbilical cord blood are associated with an increased risk of newborn hearing screening (NHS) test failure in preterm neonates.

Methods

This retrospective cohort study included 127 premature singleton infants who were born at ≤33.6 weeks. Umbilical cord plasma at birth was assayed for interleukin (IL)-6, complement C3a and C5a, matrix metalloproteinase (MMP)-9, macrophage colony-stimulating factor (M-CSF), and endostatin levels using ELISA kits. Neonatal blood C-reactive protein (CRP) levels were measured within 2 hours of birth. The primary outcome measure was a uni- or bilateral refer result on an NHS test. Univariate and multivariate analyses were applied.

Results

Fifteen (11.8%) infants failed the NHS test. In the univariate analyses, high IL-6 and low C3a levels in umbilical cord plasma, funisitis, and an elevated CRP level (>5 mg/L) in the immediate postnatal period were significantly associated with NHS test failure. However, the levels of umbilical cord plasma MMP-9, C5a, M-CSF, and endostatin were not significantly different between infants who passed and those who failed the NHS test. Multiple logistic regression analyses indicated that elevated umbilical cord plasma C3a levels were independently associated with a reduced risk of NHS test failure, whereas elevated levels of umbilical cord plasma IL-6 and high CRP levels in the immediate postnatal period were significantly associated with NHS test failure.

Conclusions

Our data demonstrated that in preterm neonates, a systemic fetal inflammatory response reflected by umbilical cord plasma IL-6 and immediate postnatal CRP levels may contribute to the risk for NHS test failure, whereas the changes in complement activation fragments initiated in utero may have protective effect of hearing screen failure.

Reviewing the WHO guidelines for antibiotic use for sepsis in neonates and children

Background Guidelines from 2005 for treating suspected sepsis in low- and middle-income countries (LMIC) recommended hospitalisation and prophylactic intramuscular (IM) or intravenous (IV) ampicillin and gentamicin. In 2015, recommendations when referral to hospital is not possible suggest the administration of IM gentamicin and oral amoxicillin. In an era of increasing antimicrobial resistance, an updated review of the appropriate empirical therapy for treating sepsis (taking into account susceptibility patterns, cost and risk of adverse events) in neonates and children is necessary. Methods Systematic literature review and international guidelines were used to identify published evidence regarding the treatment of (suspected) sepsis. Results Five adequately designed and powered studies comparing antibiotic treatments in a low-risk community in neonates and young infants in LMIC were identified. These addressed potential simplifications of the current WHO treatment of reference, for infants for whom admission to inpatient care was not possible. Research is lacking regarding the treatment of suspected sepsis in neonates and children with hospital-acquired sepsis, despite rising antimicrobial resistance rates worldwide. Conclusions Current WHO guidelines supporting the use of gentamicin and penicillin for hospital-based patients or gentamicin (IM) and amoxicillin (oral) when referral to a hospital is not possible are in accordance with currently available evidence and other international guidelines, and there is no strong evidence to change this. The benefit of a cephalosporin alone or in combination as a second-line therapy in regions with known high rates of non-susceptibility is not well established. Further research into hospital-acquired sepsis in neonates and children is required.

Quantitative Analysis of Gentamicin Exposure in Neonates and Infants Calls into Question Its Current Dosing Recommendations

Optimal dosing of gentamicin in neonates is still a matter of debate despite its common use. We identified gentamicin dosing regimens from eight international guidelines and seven Swiss neonatal intensive care units. The dose per administration, the dosing interval, the total daily dose, and the demographic characteristics between guidelines were compared. There was considerable variability with respect to dose (4 to 6 mg/kg), dosing interval (24 h to 48 h), total daily dose (2.5 to 6 mg/kg/day), and patient demographic characteristics that were used to calculate individualized dosing regimens. A model-based simulation study in 1071 neonates was performed to determine the achievement of efficacious peak gentamicin concentrations according to predefined MICs (Cmax/MIC ≥ 10) and safe trough concentrations (Cmin ≤ 2 mg/liter) with recommended dosing regimens. MIC targets of 0.5 and 1 mg/liter were used. Dosing optimization was performed giving priority to the first day of treatment and with the goal of simplifying dosing. Current gentamicin neonatal guidelines allow to achieve effective peak concentrations for MICs ≤ 0.5 mg/liter but not higher. Model-based simulations indicate that to attain peak gentamicin concentrations of ≥10 mg/liter, a dose of 7.5 mg/kg should be administered using an extended dosing interval regimen. Trough concentrations of ≤2 mg/liter can be maintained with a dosing interval of 36 to 48 h in neonates according to gestational and postnatal age. For treatment beyond 3 days, therapeutic drug monitoring is advised to maintain adequate serum concentrations.

Monitoring intraventricular vancomycin for ventriculostomy access device infection in preterm infants

PURPOSE

Ventriculitis is a known complication during external CSF drainage in preterm infants with posthaemorrhagic ventricular dilatation. Staphylococci are most frequently isolated in device-associated ventriculitis, and hence, intraventricular vancomycin is a commonly used therapy. Our aim was to study the CSF vancomycin level pattern and drug safety in ventriculostomy access device infection in preterm infants less than 28 weeks gestation.

METHODS

This single-centre, retrospective case series included seven infants with a median gestational age of 25 + 4 weeks (range 23 + 6 to 27 + 5 weeks). Ventriculitis was defined as elevated CSF white cell count of > 20/mm³ or positive CSF culture. The CSF vancomycin concentrations following intraventricular vancomycin administration were studied.

RESULTS

Forty treatment episodes of intraventricular vancomycin administration were studied in seven preterm infants. Maximum CSF vancomycin concentrations were 24.9 mg/L (3 mg, n = 8, observed concentration-time (OCT), hours (h) = 19), 96.3 mg/L (5 mg, n = 17, OCT(h) = 14), 94 mg/L (10 mg, n = 14, OCT(h) = 24), and 230.7 mg/L (15 mg, n = 1, OCT(h) = 24). The threshold for re-dosage is set at CSF vancomycin level of < 10 mg/L. In all patients, ventriculitis resolution (defined as sterile CSF and CSF WCC of < 20/mm³) was achieved in a median of 5.5 days (range 2-31 days). Individual microbiology data is provided in the online resource.

CONCLUSION

Intraventricular vancomycin is an effective treatment for ventriculostomy access device infection in preterm infants. In doses ranging from 3 to 15 mg, sufficient CSF vancomycin level is generated to achieve microbiological cure without any reported adverse effects. Daily CSF drug monitoring is recommended to define dosage interval to maintain drug concentration above breakpoint of minimum inhibitory concentration.

Neonatal Infection in Children With Cerebral Palsy: A Registry-Based Cohort Study

BACKGROUND

The goal of this study was to explore the association between neonatal infection and outcomes in children with cerebral palsy.

METHODS

We conducted a retrospective cohort study using the Canadian CP Registry. Neonatal infection was defined as meeting one of the following criteria: (1) septicemia, (2) septic shock, or (3) administration of antibiotics for ≥10 days. Phenotypic profiles of children with cerebral palsy with and without an antecedent neonatal infection were compared. Subgroup analysis was performed, stratified by gestational age (term versus preterm).

RESULTS

Of the 1229 registry participants, 505 (41.1%) were preterm, and 192 (15.6%) met the criteria for neonatal infection with 29% of preterm children having a neonatal infection compared with 6.5% in term-born children. Children with prior neonatal infection were more likely to have a white matter injury (odds ratio 2.2, 95% confidence interval 1.5 to 3.2), spastic diplegic neurological subtype (odds ratio 1.6, 95% confidence interval 1.1 to 2.3), and sensorineural auditory impairment (odds ratio 2.1, 95% confidence interval 1.4 to 3.3). Among preterm children, neonatal infection was not associated with a difference in phenotypic profile. Term-born children with neonatal infection were more likely to have spastic triplegia or quadriplegia (odds ratio 2.4, 95% confidence interval 1.3 to 4.3), concomitant white matter and cortical injury (odds ratio 4.1, 95% confidence interval 1.6 to 10.3), and more severe gross motor ability (Gross Motor Function Classification System IV to V) (odds ratio 2.6, 95% confidence interval 1.4 to 4.8) compared with preterm children.

CONCLUSIONS

Findings suggest a role of systemic infection on the developing brain in term-born infants, and the possibility to develop targeted therapeutic and preventive strategies to reduce cerebral palsy morbidity.

Sound shock response in larval zebrafish: A convenient and high-throughput assessment of auditory function

Given that hearing ability can be challenged in diverse ways, it is necessary to develop an easily conducted, high-throughput method for assessing potential auditory risks. Measuring the acoustic startle response (ASR) has become a critical behavioral method in hearing research using zebrafish (Danio rerio). In this study, changes in the activity of zebrafish larvae (10 days post fertilization (dpf)) due to exposure to a sudden easily-generated broad-band noise were automatically and objectively recorded and analyzed without building sophisticated equipments. A significant increase in activity was induced by the noise stimulation and the alterations were impaired by gentamicin. In addition, a clear dose-response trend was observed between gentamicin exposure and the impaired activity, and a similar phenomenon was observed between gentamicin exposure and damage to hair cells. Our results suggested that alterations in the activity induced by a broad-band noise can potentially be used as an efficient assay for assessing hearing ability.

Monitoring neonates for ototoxicity

OBJECTIVES

Neonates admitted to the neonatal intensive care unit (NICU) are at greater risk of permanent hearing loss compared to infants in well mother and baby units. Several factors have been associated with this increased prevalence of hearing loss, including congenital infections (e.g. cytomegalovirus or syphilis), ototoxic drugs (such as aminoglycoside or glycopeptide antibiotics), low birth weight, hypoxia and length of stay. The aetiology of this increased prevalence of hearing loss remains poorly understood.

DESIGN

Here we review current practice and discuss the feasibility of designing improved ototoxicity screening and monitoring protocols to better identify acquired, drug-induced hearing loss in NICU neonates.

STUDY SAMPLE

A review of published literature.

CONCLUSIONS

We conclude that current audiological screening or monitoring protocols for neonates are not designed to adequately detect early onset of ototoxicity. This paper offers a detailed review of evidence-based research, and offers recommendations for developing and implementing an ototoxicity monitoring protocol for young infants, before and after discharge from the hospital.

High Risk Factors Associated With Early Childhood Hearing Loss: A 3-Year Review

PURPOSE

In this study, we examined the association between risk factors for hearing loss and early childhood hearing status (normal hearing, congenital hearing loss, or delayed-onset hearing loss). Follow-up rates of audiologic care following passed or referred birth screens for children with risk factors were also examined.

METHOD

A retrospective data review was completed on 115,039 children born from 2010 to 2012. Data analyses included prevalence rates, odds ratios, and Fisher exact tests of statistical significance.

RESULTS

Ninety percent of children were born with no risk factors for hearing loss; of those, 99.9% demonstrated normal hearing by 3 years of age. Of the 10% of children born with risk factors, 96.3% demonstrated normal hearing by age 3, 1.4% presented with congenital hearing loss, and 2.3% demonstrated permanent hearing loss by age 3. Factors that placed children at the highest risk of congenital hearing impairment were neurodegenerative disorders, syndromes, and congenital infections. Factors that placed children at the highest risk of developing permanent postnatal hearing loss were congenital cytomegalovirus, syndromes, and craniofacial anomalies.

CONCLUSIONS

Certain risk factors place a child at significantly greater risk of congenital hearing impairment or developing permanent hearing loss by age 3. Follow-up diagnostic testing should remain a priority for children with certain risk factors for hearing loss.