Metabolomic Analysis Reveals the Association of Severe Bronchopulmonary Dysplasia with Gut Microbiota and Oxidative Response in Extremely Preterm Infants

Bronchopulmonary dysplasia (BPD) is a chronic lung disease mainly affecting premature infants needing ventilation or oxygen for respiratory distress. This study aimed to evaluate the molecular linkages for BPD in very and extremely preterm infants using a metabolomics-based approach. A case-control study of enrolling preterm infants born before 32 weeks gestational age (GA) was prospectively performed. These preterm infants were subsequently stratified into the following two groups for further analysis: no or mild BPD, and moderate or severe BPD based on the 2019 NICHD criteria. Urinary metabolomic profiling was performed using 1H-Nuclear magnetic resonance (NMR) spectroscopy coupled with partial least squares discriminant analysis (PLS-DA) at a corrected age of 6 months. Metabolites significantly differentially related to GA and BPD severity were performed between groups, and their roles in functional metabolic pathways were also assessed. A total of 89 preterm infants born before 32 weeks gestation and 50 infants born at term age (above 37 completed weeks' gestation) served as controls and were enrolled into the study. There were 21 and 24 urinary metabolites identified to be significantly associated with GA and BPD severity, respectively (p < 0.05). Among them, N-phenylacetylglycine, hippurate, acetylsalicylate, gluconate, and indoxyl sulfate were five metabolites that were significantly higher, with the highest importance in both infants with GA < 28 weeks and those with moderate to severe BPD, whereas betaine and N,N-dimethylglycine were significantly lower (p < 0.05). Furthermore, ribose and a gluconate related pentose phosphate pathway were strongly associated with these infants (p < 0.01). In conclusion, urinary metabolomic analysis highlights the crucial role of gut microbiota dysbiosis in the pathogenesis of BPD in preterm infants, accompanied by metabolites related to diminished antioxidative capacity, prompting an aggressive antioxidation response in extremely preterm infants with severe BPD.

The Clinical Characteristics, Microbiology and Risk Factors for Adverse Outcomes in Neonates with Gram-Negative Bacillary Meningitis

Background: We aimed to describe the clinical features of Gram-negative bacillary (GNB) meningitis in neonates and investigate the risk factors associated with final adverse outcomes of neonatal GNB meningitis. Methods: From 2003 to 2020, all neonates (aged ≤ 90 days old) with bacterial meningitis who were hospitalized in four tertiary-level neonatal intensive care units (NICUs) of two medical centers in Taiwan were enrolled. Neonates with GNB meningitis were compared with those with Streptococcus agalactiae (group B streptococcus, GBS) meningitis. Results: During the study period, a total of 153 neonates with bacterial meningitis were identified and enrolled. GNB and GBS accounted for 40.5% (n = 62) and 35.3% (n = 54) of all neonatal bacterial meningitis, respectively. In neonates with GNB meningitis, the final mortality rate was 6.5% (4 neonates died); 48 (77.4%) had neurological complications, and 26 (44.8%) of 58 survivors had neurological sequelae at discharge. Although the final outcomes were comparable between neonates with GNB meningitis and those with GBS meningitis, neonates with GNB meningitis were more likely to have more severe clinical manifestations initially and have ventriculomegaly at follow-up. After multivariate logistic regression analysis, neonates with seizure at onset, early onset sepsis, and requirement of surgical intervention for neurological complications were independently associated with final adverse outcomes. Conclusions: GNB meningitis was associated with a high risk of neurological complications and sequelae, although it did not significantly increase the final mortality rate. Close monitoring of the occurrence of neurological complications and advanced therapeutic strategies to optimize the outcomes are urgently needed in the future.

Invasive Candida parapsilosis Bloodstream Infections in Children: The Antifungal Susceptibility, Clinical Characteristics and Impacts on Outcomes

Background: Candida parapsilosis is the most common non-albicans candida species that causes invasive candidiasis, but little is known about its impacts on the outcomes of pediatric patients. We aimed to characterize the clinical characteristics, risk factors and outcomes of C. parapsilosis bloodstream infections (BSIs) in children. Methods: All pediatric patients with Candida parapsilosis BSIs between 2005 and 2020 from a medical center in Taiwan were enrolled and analyzed. The antifungal susceptibility, clinical manifestations, management and outcomes were investigated. Cases of Candida parapsilosis BSIs were compared between patients with C. albicans BSIs and other Candida spp. BSIs. Results: During the study period, 95 episodes (26.0% of total cases) of Candida parapsilosis BSIs were identified and analyzed. No significant difference was found between pediatric patients with C. parapsilosis BSIs and those with C. albicans BSIs in terms of patients' demographics, most chronic comorbidities or risk factors. Pediatric patients with C. parapsilosis BSIs were significantly more likely to have previous azole exposure and be on total parenteral nutrition than those with C. albicans BSIs (17.9 vs. 7.6% and 76.8 vs. 63.7%, p = 0.015 and 0.029, respectively). The duration of C. parapsilosis candidemia was relatively longer, and therefore patients often required a longer duration of antifungal treatment when compared with those of C. albicans candidemia, although the candidemia-attributable mortality rates were comparable. Of the C. parapsilosis isolates, 93.7% were susceptible to all antifungal agents, and delayed appropriate antifungal treatment was an independent factor in treatment failure. Conclusions: Pediatric patients with C. parapsilosis BSIs were more likely to have previous azole exposure and be on total parenteral nutrition, and the clinical significances included a longer duration of candidemia and patients often required a longer duration of antifungal treatment.

Influences of Initial Empiric Antibiotics with Ampicillin plus Cefotaxime on the Outcomes of Neonates with Respiratory Failure: A Propensity Score Matched Analysis

Background: Empiric antibiotics are often prescribed in critically ill and preterm neonates at birth until sepsis can be ruled out. Although the current guideline suggests narrow-spectrum antibiotics, an upgrade in antibiotics is common in the neonatal intensive care unit. The impacts of initial broad-spectrum antibiotics on the outcomes of critically ill neonates with respiratory failure requiring mechanical intubation have not been well studied. Methods: A total of 1162 neonates from a tertiary level neonatal intensive care unit (NICU) in Taiwan who were on mechanical ventilation for respiratory distress/failure at birth were enrolled, and neonates receiving ampicillin plus cefotaxime were compared with those receiving ampicillin plus gentamicin. Propensity score-matched analysis was used to investigate the effects of ampicillin plus cefotaxime on the outcomes of critically ill neonates. Results: Ampicillin plus cefotaxime was more frequently prescribed for intubated neonates with lower birth weight, higher severity of illness, and those with a high risk of early-onset sepsis. Only 11.1% of these neonates had blood culture-confirmed early-onset sepsis and/or congenital pneumonia. The use of ampicillin plus cefotaxime did not significantly contribute to improved outcomes among neonates with early-onset sepsis. After propensity score-matched analyses, the critically ill neonates receiving ampicillin plus cefotaxime had significantly worse outcomes than those receiving ampicillin plus gentamicin, including a higher risk of late-onset sepsis caused by multidrug-resistant pathogens (11.2% versus 7.1%, p = 0.027), longer duration of hospitalization (median [IQR], 86.5 [47–118.8] days versus 78 [45.0–106.0] days, p = 0.002), and a significantly higher risk of in-hospital mortality (14.2% versus 9.6%, p = 0.023). Conclusions: Ampicillin plus cefotaxime should not be routinely prescribed as the empiric antibiotics for critically ill neonates at birth because they were associated with a higher risk of infections caused by multidrug-resistant pathogens and final worse outcomes.

Clinical characteristics and outcomes of neonates with polymicrobial ventilator-associated pneumonia in the intensive care unit

BACKGROUND

Ventilator associated pneumonia (VAP) caused by more than one microorganisms is not uncommon and may be potentially challenging, but the relevant data is scarce in ventilated neonates. We aimed to investigate the clinical characteristics and outcomes of polymicrobial VAP in the neonatal intensive care unit (NICU).

METHODS

All neonates with definite diagnosis of VAP from a tertiary level neonatal intensive care unit (NICU) in Taiwan between October 2017 and September 2020 were prospectively observed and enrolled for analyses. All clinical features, therapeutic interventions and outcomes were compared between the polymicrobial VAP and monomicrobial VAP episodes. Multivariate regression analyses were used to find the independent risk factors for treatment failure.

RESULTS

Among 236 episodes of neonatal VAP, 60 (25.4%) were caused by more than one microorganisms. Polymicrobial VAP episodes were more likely to be associated with multidrug-resistant pathogens (53.3% versus 34.7%, P = 0.014), more often occurred in later days of life and in neonates with prolonged intubation and underlying bronchopulmonary dysplasia. Otherwise most clinical characteristics of polymicrobial VAP were similar to those of monomicrobial VAP. The therapeutic responses and treatment outcomes were also comparable between these two groups, although modification of therapeutic antibiotics were significantly more common in polymicrobial VAP episodes than monomicrobial VAP episodes (63.3% versus 46.2%; P < 0.001). None of any specific pathogens was significantly associated with worse outcomes. Instead, it is the severity of illness, including presence of concurrent bacteremia, septic shock, and requirement of high-frequency oscillatory ventilator and underlying neurological sequelae that are independently associated with treatment failure.

CONCLUSIONS

Polymicrobial VAP accounted for 25.4% of all neonatal VAP in the NICU, and frequently occurred in neonates with prolonged intubation and underlying bronchopulmonary dysplasia. In our cohort, most clinical features, therapeutic responses and final outcomes of neonates with monomicrobial and polymicrobial VAP did not differ significantly.

Therapeutic effects and outcomes of rescue high-frequency oscillatory ventilation for premature infants with severe refractory respiratory failure

Despite wide application of high frequency oscillatory ventilation (HFOV) in neonates with respiratory distress, little has been reported about its rescue use in preterm infants. We aimed to evaluate the therapeutic effects of HFOV in preterm neonates with refractory respiratory failure and investigate the independent risk factors of in-hospital mortality. We retrospectively analyzed data collected prospectively (January 2011–December 2018) in four neonatal intensive care units of two tertiary-level medical centers in Taiwan. All premature infants (gestational age 24–34 weeks) receiving HFOV as rescue therapy for refractory respiratory failure were included. A total of 668 preterm neonates with refractory respiratory failure were enrolled. The median (IQR) gestational age and birth weight were 27.3 (25.3–31.0) weeks and 915.0 (710.0–1380.0) g, respectively. Pre-HFOV use of cardiac inotropic agents and inhaled nitric oxide were 70.5% and 23.4%, respectively. The oxygenation index (OI), FiO₂, and AaDO₂ were markedly increased after HFOV initiation (all p < 0.001), and can be decreased within 24–48 h (all p < 0.001) after use of HFOV. 375 (56.1%) patients had a good response to HFOV within 3 days. The final in-hospital mortality rate was 34.7%. No association was found between specific primary pulmonary disease and survival in multivariate analysis. We found preterm neonates with gestational age < 28 weeks, occurrences of sepsis, severe hypotension, multiple organ dysfunctions, initial higher severity of respiratory failure and response to HFOV within the first 72 h were independently associated with final in-hospital mortality. The mortality rate of preterm neonates with severe respiratory failure remains high after rescue HFOV treatment. Aggressive therapeutic interventions to treat sepsis and prevent organ dysfunctions are the suggested strategies to optimize outcomes.

Safety and clinical application of nonbronchoscopic bronchoalveolar lavage in preterm neonates with clinical ventilator-associated pneumonia

BACKGROUND

The safety and clinical application of nonbronchoscopic bronchoalveolar lavage (NB-BAL) in preterm neonates with ventilator-associated pneumonia (VAP) have not been fully investigated, and limited data on the feasibility of this method are available.

METHODS

Premature infants with clinically suspected VAP between October 2017 and June 2019 were enrolled, and NB-BAL was performed. The tolerance and safety of NB-BAL were prospectively recorded during the procedure, and the clinical applications of NB-BAL were observed.

RESULTS

A total of 46 NB-BAL procedures were performed in 31 neonates with clinically suspected VAP. The median (interquartile range) gestational age and birth body weight were 28.7 (26.7-31.3) weeks and 1055.0 (817.0-1475.0) grams, respectively. Overall, all episodes of the procedure were well tolerated, with only 9 (19.5%) episodes showing transient desaturation and one patient (2.2%) showing bradycardia during the NB-BAL procedure. There were no impairments in arterial blood gas, cardiopulmonary parameters or respiratory severity scores after NB-BAL. No significant complications occurred in any of the patients who received NB-BAL. No chronic comorbidities affected the safety and clinical application of NB-BAL in these mechanically ventilated preterm neonates. NB-BAL yielded a diagnosis in 32 (69.6%) of these VAP episodes. Staphylococcus aureus was the most common isolated bacterium and accounted for 7 (15.2%) confirmed cases of VAP in our study, followed by polymicrobial microorganisms (n = 6, 13.0%). The appropriate antibiotics were prescribed and modified according to the NB-BAL results in 25 (54.3%) cases of VAP.

CONCLUSIONS

NB-BAL is a safe and clinically applicable method for determining the etiology and diagnosis of VAP in the NICU, even in extremely preterm neonates with major chronic comorbidities. Further studies to investigate the diagnostic accuracy and impact of NB-BAL on VAP treatment in neonates are warranted in the future.

Prognostic Factors and Clinical Features of Neonatal Splenic Rupture/Hemorrhage: Two Cases Reports and Literature Review

Background: Neonatal splenic rupture/hemorrhage (SRH), an extremely rare and potentially fatal presentation, can spontaneously resolve without surgical treatment; However, treatment approaches remain controversial. The present study aimed to describe and analyze the clinical features and therapies of neonatal SRH and therapeutic approaches. Methods: We present the cases of two patients and review another 37 cases reported in English-literature. The literature search included all articles published in PUBMED from inception between January 1968 and December 2019. Demographic data, precipitating factors, clinical characteristics including presenting symptoms and signs, presenting time, age at SRH presentation, imaging findings, as well as treatments and outcomes were analyzed. Results: In addition to the two cases treated at our hospital, 37 neonates with SRH were reported during the study period. The rate of full-term neonates was 72% (28/39). The cause was idiopathic in most cases, and congenital coagulation disorders were underlying causes in 13% (5/39) of the cases. The most common presenting symptom and sign of neonatal SRH were pallor or anemia, followed by abdominal discoloration/distension. Additionally, 18% (7/39) of the cases presented with scrotal hematoma or swelling. The age at SRH presentation ranged between 3 h and 5 days of age. Abdominal ultrasonography or computed tomography was used as the diagnostic tool. Twenty-seven cases (69%) received surgical management. The prognosis was comparable between the neonates treated with splenectomy and those treated with non-surgical approaches. The mortality rate was 18% (7/39) in the study cohort. SRH presentation at ≤12 h of age was associated with higher mortality compared to SRH presenting time at >12 h of age (odds ratio 25.0, 95% CI 2.514-248.575, p = 0.001). Conclusion: Our literature review revealed that the mortality rate of neonatal SRH was 18% and that the mortality risk was higher in neonates presenting with SRH symptoms and signs at ≤12 h of age.

Risk Factors of Initial Inappropriate Antibiotic Therapy and the Impacts on Outcomes of Neonates with Gram-Negative Bacteremia

BACKGROUND

Timely appropriate empirical antibiotic plays an important role in critically ill patients with gram-negative bacteremia. However, the relevant data and significant impacts have not been well studied in the neonatal intensive care unit (NICU).

METHODS

An 8-year (1 January 2007-31 December 2014) cohort study of all NICU patients with gram-negative bacteremia (GNB) in a tertiary-care medical center was performed. Inadequate empirical antibiotic therapy was defined when a patient did not receive any antimicrobial agent to which the causative microorganisms were susceptible within 24 h of blood culture sampling. Neonates with GNB treated with inadequate antibiotics were compared with those who received initial adequate antibiotics.

RESULTS

Among 376 episodes of Gram-negative bacteremia, 75 (19.9%) received inadequate empirical antibiotic therapy. The cause of inadequate treatment was mostly due to the pathogen resistance to prescribed antibiotics (88.0%). Bacteremia caused by Pseudomonas aeruginosa (Odds ratio [OR]: 20.8, P < 0.001) and extended spectrum β-lactamase (ESBL)-producing bacteria (OR: 18.4, P < 0.001) had the highest risk of inadequate treatment. Previous exposure with third generation cephalosporin was identified as the only independent risk factor (OR: 2.52, 95% CI: 1.18-5.37, P = 0.018). Empirically inadequately treated bacteremias were significantly more likely to have worse outcomes than those with adequate therapy, including a higher risk of major organ damage (20.0% versus 6.6%, P < 0.001) and infectious complications (25.3% versus 9.3%, P < 0.001), and overall mortality (22.7% versus 11.0%, P = 0.013). Conclusions: Inadequate empirical antibiotic therapy occurs in one-fifth of Gram-negative bacteremias in the NICU, and is associated with worse outcomes. Additional prospective studies are needed to elucidate the optimal timing and aggressive antibiotic regimen for neonates who are at risk of antibiotic-resistant Gram-negative bacteremia.

Use of high frequency oscillatory ventilator in neonates with respiratory failure: the clinical practice in Taiwan and early multimodal outcome prediction

High-frequency oscillatory ventilation (HFOV) can be a rescue for neonates with refractory respiratory failure or an early elective therapy for preterm infants with severe respiratory distress syndrome (RDS). However, little is known about the current evolution and therapeutic limitations of HFOV. We therefore aimed to describe its use in clinical practice and predict the risk of mortality for neonates receiving HFOV. A retrospective observational study of all neonates treated with HFOV in a quaternary referral NICU between January 2007 and December 2016 was conducted. We classified these patients into five subgroups based on primary respiratory diagnoses. We performed the logistic regression and decision tree regression analyses to identify independent factors of 30-day mortality following HFOV. A total of 1125 patients who were ever supported on HFOV were enrolled, of whom 64.1% received HFOV as a rescue therapy, 27.2% received it as an elective therapy, and 8.7% received it for air leak. An average oxygenation index (OI) greater than 25 in the first 24 hours after the initiation of HFOV and patients with secondary pulmonary hypertension were found to have the greatest risk of in-hospital mortality (p < 0.0001). The overall in-hospital mortality rate was 25.8% (290/1125). Decision tree regression analysis revealed that neonates with refractory respiratory failure who had a pre-HFOV OI value higher than 20.5 and OI values higher than 21.5, 23.5 and 34 at 2 hours, 6 hours, and 12 hours after the use of HFOV, respectively, had a significantly increased risk of 30-day mortality. We identified the predictors and cutoff points of OI before and after the initiation of HFOV in neonates with respiratory failure, which can be clinically used as a reference for 30-day mortality. Further efforts are still needed to optimize the outcomes.

The Off-Label Use of Inhaled Nitric Oxide as a Rescue Therapy in Neonates with Refractory Hypoxemic Respiratory Failure: Therapeutic Response and Risk Factors for Mortality

OBJECTIVES

The indication of inhaled nitric oxide (iNO) used in preterm infants has not been well defined. Neonates with refractory hypoxemia may benefit from the pulmonary vasodilatory effects of iNO. The aim of this study was to investigate the off-label use of iNO as a rescue therapy.

METHODS

Between January 2010 and December 2017, all neonates who received iNO as a rescue therapy from a tertiary-level medical center were enrolled, and those who were not diagnosed with persistent pulmonary hypertension of newborn (PPHN) were defined as having received off-label use of iNO. The controls were 636 neonates with severe respiratory failure requiring high-frequency oscillatory ventilation but no iNO.

RESULTS

A total of 206 neonates who received iNO as a rescue therapy were identified, and 84 (40.8%) had off-label use. The median (interquartile) gestational age was 30.5 (26.3-37.0) weeks. Neonates receiving iNO had significantly more severe respiratory failure and a higher oxygenation index than the controls (p < 0.001). Respiratory distress syndrome and secondary pulmonary hypertension after severe bronchopulmonary dysplasia (BPD) were the most common causes of the off-label iNO prescription. Of the 84 neonates with off-label use of iNO, 53 (63.1%) had initial improvement in oxygenation, but 44 (52.4%) eventually died. The overall mortality rate was 41.7% (86/206). After multivariate logistic regression, extremely preterm (odds ratio [OR] 5.51; p < 0.001), presence of pulmonary hemorrhage (OR 2.51; p = 0.036) and severe hypotension (OR 2.78; p = 0.008) were the independent risk factors for final mortality.

CONCLUSIONS

iNO is applicable to be an off-label rescue therapy for premature neonates with refractory hypoxemia due to severe pulmonary hypertension and bronchopulmonary dysplasia.

Childhood otitis media: Relationship with daycare attendance, harsh parenting, and maternal mental health

Psychological stress has been linked to developmental problems and poor health in children, but it is unclear whether it is also related to otitis media (OM). As part of a long-term study surveying the characteristics of childcare and development in Taiwan, we analyzed the relationship between OM and sources of psychological stress in children, such as poor maternal mental health and harsh parental discipline. We analyzed the data of 1998 children from the “Kids in Taiwan: National Longitudinal Study of Child Development & Care (KIT) Project” at the age of 3 years. Using bivariate and multivariate logistic regression models, we tested several risk factors as potential independent predictors of two outcomes: parent-reported incidence of OM and child health. The proportion of children who had developed OM in the first 3 years of their life was 12.5%. Daycare attendance (odds ratio [OR]: 1.475; 95% confidence interval [CI]: 1.063–2.046), poor maternal mental health (OR: 1.913; 95% CI: 1.315–2.784), and harsh parental discipline (OR: 1.091; 95% CI: 1.025–1.161) correlated with parent-reported occurrence of OM. These findings suggest that providing psychosocial support to both parents and children might be a novel strategy for preventing OM.

Characterization of group B Streptococcus colonization in full-term and Late-Preterm neonates in Taiwan

BACKGROUND

Group B streptococcus (GBS) infections can be life-threatening in newborns. This study aimed to analyze GBS carriage status and genotypic diversity in healthy neonates after implementation of intrapartum antibiotic prophylaxis (IAP) in Taiwan.

METHODS

Newborns carrying GBS were identified from a screen of 500 newborns and followed up until their cultures turned negative. Their mothers' GBS screening data were reviewed. Molecular methods, including capsular serotyping, multilocus sequence typing and pulsed-field gel electrophoresis (PFGE), were used to analyze GBS isolates.

RESULTS

GBS colonization was detected at either the nose or anus in 11 of 500 healthy neonates (2.2%). In this group of 11 neonates, 4 had GBS serotypes II and III for 4-6 months, 1 had serotype V for 2 months, 6 had serotypes Ia, II, V, and VI for less than 1 month, and 1 had 2 different serotypes (serotypes V and II) at different times. The most prevalent serotype was II (33.3%), followed by Ia (25.0%), III (16.7%), V (16.7%), and VI (8.3%). The main sequence type was ST1 (50.0%), followed by ST19 (16.7%), ST23 (8.3%), ST24 (8.3%), ST103 (8.3%), and ST 231 (8.3%). All isolates were grouped into 5 PFGE clusters F, G, J, X, and Y, and all were susceptible to β-lactam antimicrobial agents.

CONCLUSIONS

GBS was carried in 2.2% (11/500) healthy newborns and persisted for 6 months in 3 neonates. This study makes clearer our understanding of GBS colonization, serotype distribution, and genotype distribution in healthy neonates.

Understanding how to enhance efficacy and effectiveness of feedback via e-portfolio: a realist synthesis protocol

INTRODUCTION

The validity of feedback as one of the defining components for electronic portfolios (e-portfolios) to be effective and efficacious has yet to be demonstrated. While the literature has shown individual beneficial features of e-portfolios and feedback per se, evidence of feedback as mediated through technology directly resulting in improved educational practice is scarce. The explanation of how feedback via e-portfolio improves educational practice is particularly vague.

METHODS AND ANALYSIS

The aim of this research is to unpack how and why feedback via e-portfolio is likely to flourish or wither in its path. Given the complexity of intervention, we will apply a theory-driven approach for evidence synthesis called realist synthesis. Informed by realist philosophy of science, it seems the most appropriate method because it explores observed outcomes (O) in terms of causal relationship between relevant contexts (C) and generating mechanisms (M). Initial programme theory will be developed through literature scoping. Later on it will be tested against purposively gathered evidence (through database and journal search), which simultaneously will be evaluated for rigour and relevance (whether method used are trustworthy and whether data contributes to theory building). We strive to (1) uncover 'context sensitive' mechanisms that generate feedback via e-portfolio to be (in) effective and (2) define in what circumstances is this mostly likely to occur.

ETHICS AND DISSEMINATION

The synthesis report will be written according to the RAMESES guidelines and its findings will be published in peer reviewed articles and presented at relevant conferences. The aim is to inform: (1) policy and decision makers for future-course design; (2) medical educators/clinical supervisors and learners for improved educational use. No formal ethical approval is required.

PROSPERO REGISTRATION NUMBER

120863.

Molecular Characteristics and Antimicrobial Resistance of Group B Streptococcus Strains Causing Invasive Disease in Neonates and Adults

We aimed to analyze the molecular characteristics, clonality and antimicrobial resistance profiles of group B streptococcus (GBS) isolates collected in Taiwan from invasive diseases and carriage. Multilocus sequence typing (MLST) was used to assess the genetic diversity of 225 GBS strains from neonates and adults with invasive GBS diseases. 100 GBS strains collected from colonized pregnant women during the same period were compared, and all strains were characterized for one of nine capsule genotypes. We also determined the susceptibilities of all GBS isolates to various antimicrobial agents. The most frequently identified serotypes that caused invasive disease in neonates were III (60.6%) and Ia (17.3%), whereas type VI (32.7%), Ib (19.4%), and V (19.4%) were the most common to cause invasive disease in adults. Serotype VI was the leading type that colonized pregnant women (35.0%). Twenty-six sequence types (STs) were identified, and 90.5% of GBS strains were represented by 6 STs. ST-17 and ST-1 were more prevalent in invasive diseases in neonates and adults, respectively. The majority of serotype III and VI isolates belonged to clonal complex (CC)-17 and CC-1, respectively. ST-17 strains were more likely to cause meningitis and late-onset disease than other strains. In addition, ST-12 and ST-17 GBS strains showed the highest rate of resistance to erythromycin and clindamycin (range: 75.8–100%). In conclusion, CC-17/type III and CC-1/type VI are the most important invasive pathogens in infants and non-pregnant adults in Taiwan, respectively. GBS genotypes vary between different age groups and geographical areas and should be considered during GBS vaccine development.

'I did not check if the teacher gave feedback': a qualitative analysis of Taiwanese postgraduate year 1 trainees' talk around e-portfolio feedback-seeking behaviours

OBJECTIVES

Despite feedback being an extensively researched and essential component of teaching and learning, there is a paucity of research examining feedback within a medical education e-portfolio setting including feedback-seeking behaviours (FSBs). FSBs can be understood within a cost-value perspective. The objective of this research is to explore the factors that influence postgraduate year 1 (PGY1) trainee doctors' FSBs via e-portfolios.

SETTING

Postgraduate education provision in the largest teaching hospital in Taiwan.

PARTICIPANTS

Seventy-one PGY1s (66% male).

METHODS

A qualitative semistructured one-to-one interview method was adopted. Interviews were audio recorded, transcribed verbatim, anonymised and checked for completeness. Data were analysed inductively via thematic framework analysis and deductively informed using FSB theory. The process comprised data familiarisation, identification of the themes, charting and data interpretation.

RESULTS

Two main themes of FSB related and e-portfolio related were identified. We present the theme focussing on FSB here to which n=32 (22 males, 10 females) of the n=71 participants contributed meaningfully. Subthemes include factors variously affecting PGY1s' positive and negative FSBs via e-portfolios at the individual, process and technological levels. These factors include learner-related (internal values vs social influence, forced reflection); teacher-related (committed educators vs superficial feedback); technology-related (face-saving vs lagging systems; inadequate user-interface) and process-related (delayed feedback, too frequent feedback) factors.

CONCLUSIONS

Our findings reveal the complexity of PGY1s' FSBs in an e-portfolio context and the interaction of numerous facilitating and inhibiting factors. Further research is required to understand the range of facilitating and inhibiting factors involved in healthcare learners' FSBs across different learning, social, institutional and national cultural settings.

Risk Factors and Outcomes of Recurrent Candidemia in Children: Relapse or Re-Infection?

In this paper, our aim was to investigate the incidence, clinical characteristics, risk factors, and outcomes of recurrent candidemia in children. We retrospectively reviewed all children with candidemia from a medical center in Taiwan between 2004 and 2015. Two episodes of candidemia ≥30 days apart with clinical and microbiological resolution in the interim were defined as "late recurrence", and those that had 8⁻29 days apart from previous episodes were defined as "early recurrence". 45 patients (17.2%) had 57 episodes of recurrent candidemia, and 24 had 28 episodes of late recurrent candidemia. The median time between recurrences was 1.8 months (range: <1 month to 13 months). Of those, 29 had relapsed candidemia and 28 were re-infected by different Candida species (n = 24) or by different strains (n = 4). Recurrent candidemia patients were more likely to require echinocandins treatment, had a longer duration of candidemia, and higher rate of treatment failure (p = 0.001, 0.014, and 0.012, respectively). Underlying gastrointestinal diseases (Odds ratio (OR) 3.84; 95% Confidence interval (CI) 1.81⁻8.12) and neurological sequelae (OR 2.32; 95% CI 1.15⁻4.69) were independently associated with the development of recurrent candidemia. 17.2% of pediatric patients with candidemia developed recurrent candidemia, and approximately half were re-infected. Underlying gastrointestinal diseases and neurological sequelae were the independent risk factors for recurrent candidemia.

Comparison of the incidence, clinical features and outcomes of invasive candidiasis in children and neonates

Background

Invasive candidiasis differs greatly between children and neonates. We aimed to investigate the different therapeutic approaches and their effects on treatment outcomes of these two groups.

Methods

Episodes of neonatal invasive candidiasis were compared with non-neonatal pediatric episodes during a 12-year cohort study. Clinical isolates were documented by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and DNA sequencing, and antifungal susceptibility testing was performed.

Results

A total of 342 episodes of invasive candidiasis (113 neonatal and 229 non-neonatal pediatric episodes) in 281 pediatric patients (96 neonates and 185 children) were identified. Candida albicans was the most common pathogen causing invasive candidiasis in neonates and children (47.8% vs. 44.1%). The antifungal susceptibility profiles were not significantly different between neonates and children. More neonates received amphotericin B as therapy, whereas more children received fluconazole or caspofungin. Compared with children, neonates had a significantly longer duration of fungemia, higher rates of septic shock (34.5% vs. 21.8%; P = 0.013), sepsis-attributable mortality (28.3% vs. 17.5%; P = 0.024) and in-hospital mortality (42.7% vs. 25.4%; P = 0.004) than children. Independent risk factors for treatment failure of invasive candidiasis were septic shock (odds ration [OR] 16.01; 95% confidence interval [CI] 7.64–33.56; P <  0.001), delayed removal of intravenous catheter (OR 6.78; 95% CI 2.80–17.41; P <  0.001), renal failure (OR 5.38; 95% CI 1.99–14.57; P = 0.001), and breakthrough invasive candidiasis (OR 2.99; 95% CI 1.04–8.67; P = 0.043).

Conclusions

Neonatal invasive candidiasis has worse outcomes than non-neonatal pediatric candidiasis. Neonatologists and pediatricians must consider age-specific differences when developing treatment and prevention guidelines, or when interpreting studies of other age groups.

Incidence, clinical features, and implications on outcomes of neonatal late-onset sepsis with concurrent infectious focus

BACKGROUND

Neonatal bloodstream infection (BSI) is the most important cause of morbidity and mortality in the neonatal intensive care unit (NICU). Although most neonatal BSIs are primary bacteremia, some are associated with a focus of infection. This distinction is not well characterized.

METHODS

All patients with neonatal late-onset sepsis (LOS) between January 2006 and December 2013 were enrolled. LOS was categorized as a BSI with a concurrent focus of infection if LOS occurred before or within 24 h after the diagnosis of a specific infectious entity, and as "primary bacteremia" if no concurrent focus of infection was identified. Data concerning demographics, hospital course, microbiology, and outcomes were compared via univariate and multivariate analyses.

RESULTS

Of 948 episodes of neonatal LOS, 781 (82.4%) were primary bacteremia, whereas 167 (17.6%) were associated with a known focus of infection, including meningitis (n = 51, 5.4%), ventilator-associated pneumonia (VAP) (n = 36, 3.8%), catheter-related bloodstream infections (n = 57, 6.0%), and necrotizing enterocolitis (NEC) (n = 21, 2.2%). The majority of NEC-associated BSIs were caused by gram-negative bacilli (85.7%). Group B streptococcus accounted for nearly one-third of all meningitis cases (29.4%). Although sepsis-attributable mortality was comparable between primary bacteremia and neonatal BSIs with a focus of infection, neonatal BSIs with meningitis, VAP, and NEC had significantly higher rates of infectious complications. The independent risk factors of sepsis-attributable mortality were infectious complications (Odds ratio [OR] 6.98; 95% confidence interval [CI] 3.64-13.39, P < 0.001); history of one or more than one previous episode(s) of BSI (OR 2.40 and 7.40; 95% CI 1.21-4.74 and 3.70-14.78, P = 0.012 and <0.001, respectively); and underlying secondary pulmonary hypertension in neonates (OR 4.77; 95% CI 1.91-11.96, P = 0.001).

CONCLUSIONS

A considerable proportion of neonatal LOS can be associated with known infectious foci in the NICU. The microbiologic etiology of neonatal LOS with a concurrent focus of infection is significantly different from that of primary bacteremia. Neonatal BSIs with concurrent meningitis, VAP, or NEC are significantly more likely to have infectious complications. This association independently leads to sepsis-attributable mortality.

Clinical Manifestations, Outcomes, and Etiologies of Perinatal Stroke in Taiwan: Comparisons between Ischemic, and Hemorrhagic Stroke Based on 10-year Experience in A Single Institute

BACKGROUND

Perinatal stroke is a common cause of established neurological sequelae. Although several risk factors have been identified, many questions regarding causes and clinical outcomes remain unanswered. This study investigated the clinical manifestations and outcomes of perinatal stroke and identified its etiologies in Taiwan.

METHODS

We searched the reports of head magnetic resonance imaging and computed tomography performed between January 2003 and December 2012. The medical records of enrolled infants with perinatal stroke were also reviewed.

RESULTS

Thirty infants with perinatal stroke were identified; 10 infants had perinatal arterial ischemic stroke (PAIS) and 20 had perinatal hemorrhagic stroke (PHS). Neonatal seizure was the most common manifestation and presented in 40% of infants with PAIS and 50% of infants with PHS. All survivors with PAIS and 77% of the surviving infants with PHS developed neurological sequelae. Acute seizure manifestation was associated with poststroke epilepsy in infants with PHS but not in infants with PAIS (86% vs. 0%, p=0.005). PAIS was mostly caused by dysfunctional hemostasis (20%) and embolism (20%), whereas PHS was mostly attributable to birth asphyxia (30%).

CONCLUSION

Perinatal stroke is associated with high mortality and morbidity rates in infants. Clinically, it can be difficult to distinguish PAIS and PHS. One should keep a high level of suspicion, especially for PHS, if infants develop unexplained seizure, cyanosis, conscious change, anemia, and/or thrombocytopenia. A systematic diagnostic approach is helpful in identifying the etiologies of perinatal stroke.

Clinical and microbiological characteristics, and impact of therapeutic strategies on the outcomes of children with candidemia

We aimed to determine the clinical and microbiological characteristics of Candida bloodstream infections in children and the impact of therapeutic strategies on outcomes. All pediatric patients with candidemia from a medical center in Taiwan over a 13-year period (2003-2015) were included and a total of 262 patients with 319 episodes of candidemia were analyzed. Overall susceptibility to fluconazole was 86.1%. Cumulative mortality at 7 and 30 days after the first episode of candidemia was 13.4% and 25.2%, respectively. The overall in-hospital mortality rate was 35.1%. The treatment outcomes did not change over the study period. Multivariate analysis showed that delayed catheter removal (odds ratio [OR], 5.52; 95% confidence interval [CI]: 2.97-10.25), septic shock (OR, 5.49; 95% CI: 2.85-10.57), and breakthrough candidemia (OR, 3.66; 95% CI: 1.43-9.35) were independently associated with clinical treatment failure. In children with candidemia, underlying renal insufficiency and hematological/oncological malignancy, delayed catheter removal, and septic shock at onset were independently associated final in-hospital mortality. Analyzing the subgroup of non-neonatal children did not change the findings. We concluded overall mortality of pediatric candidemia remains high during the past decade. Prompt early catheter removal and aggressive treatment strategy in patients with septic shock would be critical to improve outcomes.

Breakthrough candidemia in children: clinical and microbiological characteristics, therapeutic strategies and impact on outcomes

AIM

To assess the characteristics, treatments, risk factors and outcomes of breakthrough candidemia in children.

MATERIALS & METHODS

Episodes of breakthrough candidemia in children were compared with the remaining episodes in a 13-year cohort study.

RESULTS

Out of 319 episodes, 45 (14.1%) were breakthrough candidemia. Breakthrough candidemia occurred in patients with more acutely ill conditions, and the majority was caused by non-albicans Candida species (73.3%; 33 episodes). A total of 79.1% of breakthrough candidemia were caused by antifungal-susceptible Candida isolates and emergence of resistance was the mechanism in five cases of patients receiving fluconazole. Episodes of breakthrough candidemia had significantly higher illness severity and higher rates of fungemia-attributable mortality.

CONCLUSION

Breakthrough candidemia independently contributed to unfavorable outcomes, and more aggressive treatment strategies are warranted when breakthrough candidemia is encountered.

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.

Clinical and Molecular Characteristics of Neonatal Extended-Spectrum β-Lactamase-Producing Gram-Negative Bacteremia: A 12-Year Case-Control-Control Study of a Referral Center in Taiwan

Extended-spectrum β-lactamase (ESBL)-producing Gram-negative bacteremia (GNB) in the neonatal intensive care unit was characterized by comparison with two control groups: a susceptible control group and a general base population group over 2001 to 2012. The influence of ESBL production on mortality was studied in all study subjects and ESBL-GNB isolates were microbiologically characterized. We identified 77 episodes of ESBL-GNB (14.2% of all neonatal late-onset GNB), which were caused by Klebsiella spp. (62.3%), E. coli (20.8%) and Enterobacter spp. (16.9%). Most ESBL-GNB strains were genetically unrelated and the SHV-type ESBLs were the most prevalent (67% of isolates). Comparison with both control groups disclosed previous usage of 3^rd generation cephalosporin (odds ratio [OR], 4.72; 95% confidence interval [CI], 2.03–10.97; P < 0.001), and underlying renal disease (OR, 4.07; 95% CI, 1.10–15.08; P = 0.035) as independent risk factors for ESBL-GNB. Inadequate empiric antibiotics, a higher illness severity, higher rates of infectious complications and sepsis-attributable mortality were more frequently seen in neonates with ESBL-GNB than those with non-ESBL GNB (20.8% and 15.6% vs. 9.2% and 7.9%, respectively; P = 0.008 and 0.049, respectively). Neonates with underlying secondary hypertension (OR, 7.22; 95% CI, 2.17–24.06) and infectious complications after bacteremia (OR, 6.66; 95% CI, 1.81–19.31) were identified as independent risk factor for in-hospital mortality. ESBL-GNB accounted for one-seventh of all neonatal gram-negative bacteremia, especially in neonates exposed to broad-spectrum cephalosporins. Neonates with ESBL-GNB bacteremia more frequently received inadequate empirical antibiotic therapy, which were associated with a higher rate of infectious complications and an adverse outcome.

Comparing the outcomes of different postgraduate year training programs in Taiwan

BACKGROUND

Postgraduate year training programs play an important role in the development of a comprehensive medical education. The goal of these training programs is to inculcate in physicians the expected level of skill in patient care. After the initiation of such programs in the USA, Europe, and Japan, studies were conducted in Taiwan to investigate relevant training methods, and a training system was established in 2003. Beginning with 3-month programs, followed by 6-month programs, the programs were constantly modified and enhanced by the establishment of the 1-year training program in 2011. This year was the transition period from the 6-month programs to the 1-year programs.

METHODS

We used a 50-item multiple choice question (MCQ) test and six 10-min stations for objective structured clinical examination (OSCE), which was composed of four stations relating to standardized patients and two stations concerning the clinical skill evaluation, to evaluate the learning results of the trainees. The trainees were divided into four groups according to the training program.

RESULTS

There was no significant difference between the performance of the 6 months and 1-year groups. The p values were 0.424 in the MCQ test and 0.082 in the OSCE evaluation.

CONCLUSION

A well-designed postgraduate training program should develop trainees' competencies. The results of this study may provide useful insight for ways to improve the design of training programs. Further investigation to better understand the impact of different programs is warranted.

Infectious Complications and Morbidities After Neonatal Bloodstream Infections: An Observational Cohort Study

Few data are available on the clinical characteristics of complications and morbidities after neonatal bloodstream infections (BSIs), understood as any newly infectious focus or organ dysfunction directly related to BSIs but not occur concurrently. However, these bloodstream-associated infectious complications (BSICs) contribute significantly to increased hospital stay, cost, and final mortality. We performed an observational cohort study of unselected neonatal intensive care unit (NICU) patients based on records in a large clinical database. All neonates hospitalized in our NICU with BSI between 2006 and 2013 were reviewed, and those who developed BSICs were analyzed to identify the clinical characteristics and outcomes. Multivariate logistic regression was used to identify independent risk factors for BSICs. Of 975 episodes of neonatal BSI, 101 (10.4%) BSICs occurred in 93 neonates with a median interval of 3 days (range, 0-17 days) after onset of BSI and included newly infectious focuses in 40 episodes (39.6%), major organ dysfunctions after septic shock in 36 episodes (35.6%), and neurological complications after meningitis or septic shock in 34 episodes (33.7%). All patients with BSICs encountered various morbidities, which subsequently resulted in in-hospital death in 30 (32.3%) neonates, critical discharge in 4 (4.3%), and persistent sequelae in 17 (18.3%). After multivariate logistic regression analysis, independent risk factors for BSICs included initial inappropriate antibiotics (odds ratio [OR], 5.54; 95% confidence interval [CI], 3.40-9.01), BSI with septic shock (OR, 5.75; 95% CI, 3.51-9.40), and BSI concurrent with meningitis (OR, 9.20; 95% CI, 4.33-19.56). It is worth noting that a percentage of neonates with BSI encountered subsequent sequelae or died of infections complications, which were significantly associated with initial inappropriate antibiotic therapy, septic shock, and the occurrence of meningitis. Further investigation is warranted to decrease the occurrence of BSICs due to their significant contribution toward final mortality.

Neonatal gram-negative bacillary late-onset sepsis: A case-control-control study on a prospectively collected database of 5,233 admissions

BACKGROUND

Gram-negative bacillary (GNB) bloodstream infections account for 20%-30% of neonatal late-onset sepsis (LOS). We aimed to identify the incidence, clinical characteristics, and risk factors for adverse outcomes in neonates with GNB LOS.

METHODS

All patients with GNB LOS admitted to the neonatal intensive care units (NICUs) of a university-affiliated teaching hospital in Taiwan from January 1, 2004-December 31, 2011, were enrolled. A case-control-control study was performed to evaluate risk factors for acquisition of neonatal GNB LOS.

RESULTS

Of the 5,010 neonates, 290 (5.8%) had a total of 346 episodes of GNB LOS (36.7% of total LOS), with an incidence rate of 13.6 per 10,000 neonate hospital days. The overall mortality rate was 17.6% (51/290), and the sepsis attributable mortality rate was 9.8% (34/346 episodes). After multivariate logistic regression analysis, neonates with prolonged use of total parenteral nutrition (adjusted odds ratio [OR] = 1.53; 95% confidence interval [CI], 1.02-2.29; P = .041) were independently associated with acquisition of GNB LOS. The independent predictors of in-hospital mortality were Pseudomonas aeruginosa etiology (OR = 11.45; 95% CI, 2.83-46.24) and underlying secondary pulmonary hypertension (OR = 18.02; 95% CI, 3.28-98.89), renal disease (OR = 17.16; 95% CI, 2.96-99.38), and neuromuscular comorbidities (OR = 2.72; 95% CI, 1.06-7.00).

CONCLUSION

Given the higher illness severity and sepsis-attributable mortality rate of neonatal GNB LOS in the NICU, strategies to reduce the incidence need to be addressed urgently.

Serum Lactate, Brain Magnetic Resonance Imaging and Outcome of Neonatal Hypoxic Ischemic Encephalopathy after Therapeutic Hypothermia

BACKGROUND

Serum lactate was used to predict the severity and outcome of neonatal hypoxic ischemic encephalopathy (HIE) before the era of therapeutic hypothermia (TH). There is no report on neurodevelopment (ND) outcome of neonates with HIE treated with TH in Taiwan.

METHODS

Between April 2011 and December 2012, newborn infants admitted to Chang Gung Memorial Hospital (CGMH), with gestational age > 35 weeks and birth weight ≥ 1800 g, who had acute perinatal events, evidence of significant fetal compromise, and ongoing clinical encephalopathy were prospectively enrolled for TH. Whole body cooling method was used to maintain the affected neonate's esophageal temperature at 33.5 ± 0.5 °C for 72 hours. Demographic data were recorded and hemogram, biochemical parameters, serum lactate, and creatine kinase (CK) were measured as well. Brain magnetic resonance imaging (MRI) was performed between 7 and 14 days of life. ND outcome of infants was evaluated by Bayley Scales of Infant Development, third edition (BSID-III) at 24 months of corrected age. Poor ND (PND) outcome was defined as infants surviving with either disability or ND delay.

RESULTS

Seventeen patients were enrolled. Fifty-nine percent of babies (10/17) were born through cesarean section and 77% of babies (13/17) were transferred from outside hospitals. Six babies were moderate HIE and 11 babies were severe HIE. Among the 14 surviving patients, eight infants had PND outcome. There was no difference in demographic data between infants with and without PND. Serum level of lactate (mg/dL) after 72 hours of TH was higher (35.6 vs. 13.8, p = 0.042) in infants with PND. Neonates with abnormal brain MRI findings were also associated with PND (p = 0.01).

CONCLUSION

This is the first report on ND outcome of neonates with HIE treated with TH in Taiwan. Higher serum level of lactate following TH and abnormal results of brain MRI are associated with poor ND outcome.

Characteristics of neonates with culture-proven bloodstream infection who have low levels of C-reactive protein (≦10 mg/L)

Background

Elevated C-reactive protein (CRP) level is widely used in clinical practice as a marker to distinguish between neonates with or without sepsis. However, some neonates with bacteremia have a CRP level within the normal range and they are not well characterized.

Methods

All episodes of neonatal culture-proven bloodstream infections (BSIs) between July 2004 and June 2012 were enrolled. Patients characteristics were compared for three CRP groups (low, ≤ 10 mg/L; intermediate, 11–100 mg/L; and high, > 100 mg/L) using the Chi-square test and one-way ANOVA. The sepsis-attributable mortality rates were compared using logistic regression analyses.

Results

Of 986 episodes of neonatal BSI, 247 (25.1 %) had CRP ≤10 mg/L at the onset of clinical sepsis. In the low CRP group, patients had lower gestational age and birth weight, and an earlier occurrence of BSI. Patients with underlying gastrointestinal pathology, renal disorders, cholestasis, and pulmonary hypertension had a non-significant elevated CRP level at the onset of sepsis. In the blood culture of the low CRP group, coagulase-negative staphylococci (CoNS) were relatively more common (55.9 %, p < 0.001) than the other two groups, although one-fourth were infected with gram-negative bacilli (19.0 %), fungi (2.8 %), or polymicrobial pathogens (3.6 %). Of the BSIs with initial low CRP, 29.1 % were treated with inadequate antibiotics, 13.0 % progressed to septic shock, and 5.3 % had infectious complications. The sepsis-attributable mortality rate was lower in the low CRP group (4.9 %) than in the high CRP group (13.6 %).

Conclusions

A considerable proportion of neonatal BSIs had a normal or low initial CRP level (≤10 mg/L), which was more likely to occur in low birth weight or extremely preterm infants, those with earlier onset of sepsis, and those infected with CoNS. Plasma CRP level should not be used to rule out severe culture-proven sepsis or guide the empirical choice of antibiotics.

Prognostic factors and concomitant anomalies in neonatal gastric perforation

OBJECTIVE

Neonatal gastric perforation is a rare and serious issue. This study aimed to highlight the vital clinical features and identify prognostic factors in such cases.

DESIGN, SETTING, PATIENTS, INTERVENTIONS, AND MEASUREMENTS

Medical charts from January 1997 through December 2008 were reviewed retrospectively. Neonates with a diagnosis of gastric perforation were included.

RESULTS

Thirteen patients were identified with a male:female ratio of 9:4. Five (38%) were preterm infants. The mortality rate was 30% (4/13), and the median age of onset was 3 days (range: 1-14 days). The most common presenting sign was abdominal distension, followed by respiratory distress and vomiting. Except for one patient in whom gastric perforation was diagnosed during surgical repair for gastroschisis, all patients had pneumoperitoneum on admission; 70% and 46% of patients had peritonitis and sepsis, respectively. Concomitant gastrointestinal (GI) tract anomalies or disorders included ischemic bowel/necrotizing enterocolitis (5 patients), intestinal malrotation (2), duodenal web (1), hiatal hernia (1), and gastroschisis (1), which necessitated secondary operations during hospitalization in 5 patients. Seven patients had leukopenia on admission, and 9 developed thrombocytopenia in the following 48 h. All patients who died presented with leukopenia on admission and thrombocytopenia in the following 48 h, yielding sensitivity and specificity rates of 100% and 67%, respectively.

CONCLUSIONS

Neonatal gastric perforation is often concomitant with GI anomalies or inflammatory/infectious disease. Patients who were outborn and those with leucopenia, peritonitis, and thrombocytopenia development within 48 h were at risk for poor outcome.

Breakthrough bacteremia in the neonatal intensive care unit: incidence, risk factors, and attributable mortality

BACKGROUND

An episode of breakthrough bacteremia, which was defined as positive blood cultures despite appropriate antibiotic therapy, imposes a treatment challenge in the neonatal intensive care unit (NICU).

METHODS

All episodes of breakthrough bacteremia from a tertiary level NICU in Taiwan between 2004 and 2011 were analyzed and compared with nonbreakthrough bacteremia.

RESULTS

Breakthrough bacteremia was identified in 7.6% (72/942) of neonatal bacteremia, and 43 (59.7%) occurred as recurrent episodes. Gram-negative organisms (41.7%) and fungi (15.3%) accounted for more than half of all microorganisms in breakthrough bacteremia. Compared with nonbreakthrough bacteremia, breakthrough bacteremia was significantly associated with more severe disease, was more likely to require aggressive therapies, and had a higher rate of infectious complications. Previous use of broad-spectrum antibiotics (odds ratio [OR], 7.54; P < .001) and particular microbial etiologies (Pseudomonas aeruginosa: OR, 4.40; P = .025; fungi: OR, 2.70; P = .013) were independent risk factors for developing breakthrough bacteremia. The crude sepsis-attributable mortality rate was greater in breakthrough bacteremia episodes (16.7% vs 6.4%; P = .004), and this condition was independently associated with an increased risk of death (OR, 2.14; 95% confidence interval, 1.04-4.40; P = .040).

CONCLUSION

Breakthrough bacteremia is not uncommon (7.6% of all bacteremia) in NICUs and represents a more severe form of neonatal bacteremia that is independently associated with an increased risk of death.

Unusual Presentation of Renal Vein Thrombosis in a Preterm Infant

Neonatal renal vein thrombosis is the most common vascular condition in the newborn kidney, which could lead to serious complication in infants undergoing intensive care. In this study, we report the case of a preterm infant with left renal vein and inferior vena cava thrombosis, presented with gross hematuria, thrombocytopenia, transient hypertension, and adrenal hemorrhage. Supportive care was offered instead of heparin therapy or thrombolytic agents. In conclusion, our case teaches that, despite the lack of a clinically obvious shock event, renal vein thrombosis should be considered in a macrohematuric newborn without renal failure.

Risk factors and outcomes for multidrug-resistant Gram-negative bacteremia in the NICU

OBJECTIVES

To assess the risk factors antibiotic therapy and outcomes of multidrug-resistant (MDR) Gram-negative bacilli (GNB) bacteremia in NICU patients.

METHODS

Episodes of MDR GNB bacteremia were compared with a non-MDR GNB bacteremia group in an 8-year cohort study.

RESULTS

Of 1106 bacteremias, 393 (35.5%) were caused by GNB. Seventy (18.6%) were caused by an MDR strain. The most frequent mechanism of resistance was extended-spectrum β-lactamase production (67.1%), mainly by Klebsiella pneumoniae (59.6%). Previous antibiotic exposure to third-generation cephalosporin (odds ratio [OR]: 5.97; 95% confidence interval [CI]: 2.37-15.08; P < .001) and carbapenem (OR: 3.60; 95% CI: 1.26-10.29; P = .017) and underlying renal disease (OR: 7.08; 95% CI: 1.74-28.83; P = .006) were identified as independent risk factors for MDR GNB acquisition. Patients with MDR GNB bacteremia more likely received inadequate initial antibiotic therapy (72.9% vs 7.8%; P < .001) had higher rates of infectious complication (21.4% vs 10.5%; P = .011) and overall case fatality +rate (28.6% vs 10.5%; P < .001). Independent risk factors for overall mortality were presence of infectious complications after bacteremia (OR: 3.16; 95% CI: 1.41-7.08; P = .005) and underlying secondary pulmonary hypertension with or without cor pulmonale (OR: 6.19; 95% CI: 1.88-20.31; P = .003).

CONCLUSIONS

MDR GNB accounted for 18.6% of all neonatal GNB bacteremia in the NICU, especially in those with previous broad-spectrum antibiotic therapy and underlying renal disease. The most frequent mechanism of resistance was extended-spectrum β-lactamase (ESBL) production. Neonates with MDR GNB were more likely to develop infectious complications, which were independently associated with a higher overall case-fatality rate.

Polymicrobial bloodstream infection in neonates: microbiology, clinical characteristics, and risk factors

Background

Polymicrobial bloodstream infections (PBSIs) have been associated with complex underlying medical conditions and a high incidence of specific microorganisms in several settings, but the relevant data are scarce in neonates.

Methods

Positive blood cultures from January 2004 to December 2011 in the neonatal intensive care unit (NICU) of Chang Gung Memorial Hospital (CGMH) were reviewed. Each neonate with PBSI (case episode) was matched to two episodes of monomicrobial BSI (control episode) by birth weight, gestational age and gender. Records were reviewed to compare their underlying medical conditions, organisms isolated, adequacy of therapy, clinical characteristics and outcomes.

Results

Forty-five episodes of PBSI (4.4% of all neonatal BSIs) were identified in 43 neonates. Gram-negative organisms constituted 59.8% of all PBSI pathogens, and 33 (73.3%) of PBSIs were caused by at least one Gram-negative organism. PBSIs were significantly more likely to be the recurrent episode and have endotracheal tube in place. No significant difference was found between PBSIs and controls in terms of demographics and most chronic conditions. PBSIs were significantly associated with a higher severity of illness, a longer duration of septic symptoms, and a higher rate of modification of antimicrobial regimens than monomicrobial BSIs. However, the sepsis-attributable mortality rates were comparable between these two groups.

Conclusions

In the NICU, PBSIs were more often caused by Gram-negative bacilli, and often occurred in neonates without any chronic conditions. The clinical significance of PBSIs included a more severe illness, longer duration of septic symptoms and a higher rate of modification of antimicrobial regimens.

Early detection of minor neurodevelopmental dysfunctions at age 6 months in prematurely born neonates

OBJECTIVE

To investigate the 6-month neurodevelopmental outcomes of prematurely born neonates and find the determining neonatal factors of minor neurological dysfunctions (MNDs).

STUDY DESIGN

We examined data collected prospectively on 151 infants born before 37th week of gestation in 2009-2010 who were assessed at 6 months corrected age with the Bayley Scales of Infant Development-2nd Edition (BSID-II) and the Denver Developmental Screening Test (DDST).

RESULTS

Of 151 neonates born before 37 weeks, 20 (13.2%) had MNDs at 6 months corrected age. These proportions were 21.6%, 13.2%, and 8.2% for neonates born before 28 weeks, 29 weeks to 32 weeks, and 33 weeks to 36 weeks, respectively. Half of neonates with MNDs have a birth body weight of less than 1000g. BSID-II and DDST are highly correlated in assessing the MNDs of premature neonates at 6 months corrected age. MND was independently associated with postnatal corticosteroid use (odds ratio [OR], 11.2; 95% confidence interval [CI], 1.9-66.0, P=0.008) and cholestasis (OR, 6.2; 95% CI, 1.16-33.1, P=0.033).

CONCLUSIONS

Premature neonates, even those born at 33 to 36 weeks, are found to have MNDs as early as 6 months corrected age by BSID-II and DDST, with risk increasing as gestation decreases.

Prevalence and pathogen distribution of neonatal sepsis among very-low-birth-weight infants

BACKGROUND

Neonatal sepsis contributes to great mortality and morbidity among very-low-birth-weight (VLBW) infants. Prevalence and pathogen distribution of sepsis in the neonatal intensive care units (NICUs) vary with time and geographic location. Such information serves as a guide for selection of empirical antibiotics coverage.

METHODS

This is a case series study performed by retrospective chart review of VLBW infants (birth body weight, BBW, <1500 g) in a medical center during a 5-year period from January 2005 to December 2009. Episodes of positive blood cultures, pathogen distribution and related clinical manifestations were described.

RESULTS

A total of 158 episodes of sepsis were identified from 1042 VLBW infants. Sepsis rate was 152 per 1000 live births. The vast majority of infections (60.7%) were caused by Gram-positive organisms [G(+)], and overall Coagulase-negative staphylococci (CoNS) (52.5%) were the most common pathogen identified. Prevalence for early-onset sepsis (EOS) was 1% and for late-onset sepsis (LOS) was 14.2%. Infants with EOS had a much higher case fatality rate than LOS (40% vs. 4.7%). Escherichia coli (40%) were the leading pathogen of EOS while CoNS (54.7%) was the leading pathogens of LOS. Overall, apnea and/or bradycardia and/or cyanosis (65.8%), poor activity (48.7%), and increased respiratory effort (43.0%) were the most common presenting features of sepsis.

CONCLUSION

Unlike term infants, Gram-negative organism and E coli were the leading pathogen of EOS among VLBW infants. Judicious and timely use of antibiotic therapy is crucial in the care of VLBW infants.

Analysis of incidence and risk factors of retinopathy of prematurity among very-low-birth-weight infants in North Taiwan

BACKGROUND

Although significant advances have been made in perinatal care, retinopathy of prematurity (ROP) remains a serious complication in prematurely born individuals. There have been limited studies on ROP in Taiwan, and most of those existing reports are outdated.

METHODS

This retrospective study included 252 very-low-birth-weight (VLBW) infants admitted to the neonatal intensive care unit of Chang Gung Children's Hospital over a 2-year period between July 2005 and June 2007. All infants were examined for ROP according to the guidelines published by the American Academy of Pediatrics. The relationship between clinical risk factors and the development of ROP was analyzed.

RESULTS

Of the 252 VLBW infants, 216 met the screening criteria. Of the 216, 99 (45.8%) had ROP. Compared with neonates born at 29 weeks of gestational age (GA) or later, those very premature infants of ≤25 weeks' and 26-28 weeks' GA had increased odds ratios (OR) of 8.49 and 3.19, respectively, for the development of severe ROP. No ROP was detected in infants of greater than 33 weeks' GA. The simultaneous presence of a low GA, low birth weight (LBW), lower Apgar scores, hypotension, patent ductus arteriosus, septicemia, intraventricular hemorrhage, ventilator dependence, and use of postnatal steroids was associated with severe ROP. Using multiple logistic regression analyses for ROP, only maternal preeclampsia [OR, 2.52; confidence interval (CI), 1.32-4.7]; duration of mechanical ventilation (OR, 1.06; CI, 1.04-1.08); and LBW (OR, 2.62; CI, 1.370-3.375) predicted the development of threshold ROP.

CONCLUSION

The incidence of ROP among VLBW infants was 45.8%; 19.0% had severe ROP. Infants of lower GAs and/or with LBW, whose mother had preeclampsia or who had a long duration of mechanical ventilation are at risk for the development of threshold ROP.

Characterization of tolerance induction through prenatal marrow transplantation: the requirement for a threshold level of chimerism to establish rather than maintain postnatal skin tolerance

Hematopoietic chimerism resulting from prenatal marrow transplantation does not consistently result in allotolerance for unidentified causes. In a C57BL/6-into-FVB/N murine model, we transplanted T-cell-depleted adult marrow on gestational day 14 to elucidate the immunological significance of chimerism towards postnatal tolerance. Postnatally, chimerism was examined by flow cytometry, and tolerance by skin transplantation and mixed lymphocyte reaction. Regulatory T cells were quantified by FoxP3 expression. Peripheral chimerism linearly related to thymic chimerism, and predicted the degree of graft acceptance with levels >3% at skin placement, yielding consistent skin tolerance. Low- and high-level chimeras had lower intrathymic CD3(high) expression than microchimeras or untransplanted mice. Regardless of the skin tolerance status in mixed chimeras, donor-specific alloreactivity by lymphocytes was suppressed but could be partially restored by exogenous interleukin-2. Recipients that lost peripheral chimerism did not accept donor skin unless prior donor skin had engrafted at sufficient chimerism levels, suggesting that complete tolerance can develop as a consequence of chimerism-related immunosuppression of host lymphocytes and the tolerogenic effects of donor skin. Thus, hematopoietic chimerism exerted immunomodulatory effects on the induction phase of allograft tolerance. Once established, skin tolerance did not fade away along with spontaneous regression of peripheral and tissue chimerism, as well as removal of engrafted donor skin. Neither did it break following in vivo depletion of increased regulatory T cells, and subcutaneous interleukin-2 injection beneath the engrafted donor skin. Those observations indicate that the maintenance of skin tolerance is multifaceted, neither solely dependent upon hematopoietic chimerism and engrafted donor skin nor on the effects of regulatory T cells or clonal anergy. We conclude that hematopoietic chimerism generated by in utero hematopoietic stem cell transplantation is critical to establish rather than maintain postnatal skin tolerance. Therefore, the diminution of hematopoietic chimerism below a threshold level does not nullify an existing tolerance state, but lessens the chance of enabling complete tolerance.

Effect of body weight on temperature control and energy expenditure in preterm infants

BACKGROUND

The purpose of this study was to compare resting energy expenditure (REE) in premature infants of different body weights during weaning from the incubator. We hypothesized that premature infants would respond to weaning from an incubator with an increase in REE, and that the increment would be larger in infants with lower body weights than in those with higher body weights.

METHODS

Stable preterm infants with body weights between 1800-2200 g were enrolled. REE was measured using indirect calorimetry at 1 hour before weaning and 3 hours after turning off the incubator. REE measurements from infants with higher body weight (2000-2200 g, Group A) were compared to those of infants with lower body weight (1800-2000 g, Group B).

RESULTS

A total of 22 patients were studied (10 in Group A and 12 in Group B). REE increased significantly after weaning in both groups (Group A: from 62 +/- 7 kcal/kg/day to 69 +/- 8 kcal/kg/day, p = 0.045 and Group B: from 65 +/- 5 kcal/kg/day to 70 +/- 7 kcal/kg/day, p = 0.001). However, there was no significant difference in REE increments between the two groups.

CONCLUSION

REE increased significantly in infants during weaning from an incubator. The increase in REE increment was similar in smaller (1800-2000 g) and larger (2000-2200 g) babies in this study. Weaning of preterm babies from an incubator may be safely started when their body weight reaches 1800 g.

Prenatal tolerance induction: relationship between cell dose, marrow T-cells, chimerism, and tolerance

It was reported that the dose of self-antigens can determine the consequence of deletional tolerance and donor T cells are critical for tolerance induction in mixed chimeras. This study aimed at assessing the effect of cell doses and marrow T cells on engraftment and tolerance induction after prenatal bone marrow transplantation. Intraperitoneal cell transplantation was performed in FVB/N (H-2K(q)) mice at gestational day 14 with escalating doses of adult C57BL/6 (H-2K(b)) marrows. Peripheral chimerism was examined postnatally by flow cytometry and tolerance was tested by skin transplantation. Transplantation of light-density marrow cells showed a dose response. High-level chimerism emerged with a threshold dose of 5.0 x 10(6) and host leukocytes could be nearly replaced at a dose of 7.5-10.0 x 10(6). High-dose transplants conferred a steady long-lasting donor-specific tolerance but were accompanied by >50% incidence of graft-versus-host disease. Depletion of marrow T cells lessened graft-versus-host disease to the detriment of engraftment. With low-level chimerism, tolerance was a graded phenomenon dependent upon the level of chimerism. Durable chimerism within 6 months required a threshold of > or = 2% chimerism at 1 month of age and predicted a 50% chance of long-term tolerance, whereas transient chimerism (<2%) only caused hyporesponsiveness to the donor. Tolerance induction did not succeed without peripheral chimerism even if a large amount of injected donor cells persisted in the peritoneum. Neither did an increase in cell doses or donor T-cell contents benefit skin graft survivals unless it had substantially improved peripheral chimerism. Thus, peripheral chimerism level can be a simple and straightforward test to predict the degree of prenatal immune tolerance.

Lower erythrocyte glutathione peroxidase activity in bronchopulmonary dysplasia in the first week of neonatal life

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a major pulmonary complication in premature infants and is considered a free radical disorder. Erythrocyte catalase (CAT) and cellular glutathione peroxidase (c-GPx) are antioxidant enzymes that detoxify peroxides generated from dismutation of superoxide anion. The study goal was to measure enzyme activity for preterm infants during the first week of life.

METHODS

Blood samples were collected from umbilical arterial lines or the radial artery of 44 preterm infants (gestational age range: 25-30 weeks) on days 0, 2, and 5 after delivery. Erythrocyte CAT and c-GPx activities were evaluated, while clinical data were obtained and the correlations of enzyme activity and BPD status were examined.

RESULTS

There was no correlation between enzyme activity and gestational age or birth weight. Packed red cell transfusion did not affect enzyme activity and there was no difference in CAT activity between the patient groups. C-GPx activity from preterm infants with BPD was significantly lower than those of preterm infants without BPD on day 5.

CONCLUSIONS

Erythrocyte c-GPx may play an important role in the development of BPD. Lower c-GPx activity in early post-natal life might be a risk factor of BPD.

Clinical features of testicular torsion and epididymo-orchitis in infants younger than 3 months

BACKGROUND/PURPOSE

Testicular torsion (TT) and orchitis/epididymo-orchitis (EO) are confusing and difficult for physicians to diagnose in infants younger than 3 months. The aim of the study was to delineate the etiology and the clinical features of TT and EO in this age group.

METHODS

During the period between April 1994 and September 2004, medical charts of infants younger than 3 months with TT and EO were reviewed retrospectively.

RESULTS

Sixteen patients were eligible for the study, including 9 with TT and 7 with orchitis/EO. Two infants had postnatal torsion, and the testicles were salvaged by emergent surgery. Eighty-six percent (6/7) of infants with EO/orchitis had either abnormal physical signs (fever or scrotal tenderness) or abnormal laboratory findings (leukocytosis or elevated C-reactive protein level). The sensitivity of color Doppler ultrasound to diagnose TT and EO/orchitis was 88% (7/8) and 100% (6/6), respectively. All infants (6/6) with EO/orchitis who were checked for urinary tract infection and sepsis had positive test results.

CONCLUSIONS

Pediatricians should examine the testicles meticulously after a baby is born. Orchitis/EO is highly suspected for patients associated with abnormal physical signs and laboratory findings. Prompt prescription of antibiotics is mandatory to avoid serious sequelae.

Erythrocyte anti-oxyenzyme activity in preterm infants with retinopathy of prematurity

BACKGROUND

Retinopathy of prematurity (ROP) is the main cause of visual impairment in premature infants and is considered to be a multifactorial disease. Because of the similarity between the human retina and the erythrocyte concerning their antioxidant mechanism, the aim of this study was to measure the erythrocyte anti-oxyenzyme activity of preterm infants.

METHODS

This prospective study was performed on a tertiary referral hospital. Blood samples were collected from umbilical arterial lines or the radial artery of 33 preterm infants within 24 h after delivery to evaluate erythrocyte anti-oxyenzyme activity. Clinical data and oxygen administration were obtained and the correlations of enzyme activity and ROP status were examined.

RESULTS

Gestational age, birth weight, 1-min Apgar score, and cellular glutathione peroxidase activity were significantly lower in preterm infants with ROP. There was no correlation between enzyme activity and gestational age, birth weight, or severity of ROP. There were no differences in cumulative oxygen and ventilator administration.

CONCLUSIONS

Gestational age and birth weight, 1-min Apgar score, and glutathione peroxidase activity are risk factors for ROP. Defective glutathione peroxidase activity may contribute to the initial phase of ROP.

Erythrocyte Cu/Zn Superoxide Dismutase Activity in Preterm Infants with and without Bronchopulmonary Dysplasia

BACKGROUND

Erythrocyte Cu/Zn superoxide dismutase is believed to play a major role as a first-line antioxidant defense. Studies have reported varying results from measures of superoxide dismutase activity in cord blood samples from neonates.

OBJECTIVE

The study goal was to assess enzyme activity for preterm infants representing a range of gestational ages during the 1st week of life. Clinical data were obtained and correlations with superoxide dismutase activity were examined.

METHODS

We collected blood samples from umbilical arterial lines or the radial artery of 44 preterm infants (gestational age range 25-30 weeks) on days 1, 3, and 6 after delivery and evaluated erythrocyte Cu/Zn superoxide dismutase activity.

RESULTS

There was no correlation between enzyme activity and gestational age or birth weight. Superoxide dismutase activity gradually increased in preterm infants with bronchopulmonary dysplasia on days 3 and 6, with levels significantly higher than those of preterm infants without bronchopulmonary dysplasia on day 6. We found that packed red cell transfusion did not affect erythrocyte superoxide dismutase activity in either group. However, higher cumulative oxygen administration was noted in preterm infants with bronchopulmonary dysplasia.

CONCLUSION

Higher cumulative oxygen administration may be one factor that upregulates the activity of erythrocyte superoxide dismutase.

Early-onset Escherichia coli sepsis presenting as acute scrotum in preterm infant

Epididymitis, or epididymo-orchitis, and infected hydrocele are unusual in the neonatal period. It is critical to differentiate them rapidly from testicular torsion to salvage the affected testis and avoid unnecessary surgical exploration. Escherichia coli is an important gram-negative bacteria causing diverse neonatal infections and is also the common bacteria causing epididymo-orchitis from an ascending route. We report the case of a preterm infant affected with epididymo-orchitis and infected hydrocele caused by early-onset E. coli sepsis. We highlight the importance of sampling proper cultures and using suitable antibiotics after excluding testicular torsion in a neonate with an acute scrotum.

Persistent pulmonary hypertension of the newborn: experience in a single institution

Persistent pulmonary hypertension of the newborn (PPHN) remains one of the most challenging situations in the neonatal intensive care unit, and it is associated with high mortality and morbidity. The optimal treatment for PPHN is controversial. We report our 9-year experience in the management of PPHN through a retrospective review of 29 neonates with persistent pulmonary hypertension. The diagnosis of PPHN is made by echocardiography and/or preductal and postductal oxygen tension difference. The treatment modalities include supportive medical care, vasodilator therapy, mechanical ventilation and correction of underlying conditions. The wide diversity of etiologies of PPHN, the complications of vasodilator therapy, the management of assisted ventilation, the mortality and the morbidity are evaluated. There are 29 patients enrolled in this study, including 18 male and 11 female babies. Twenty-two patients (72%) are referred from other hospitals. The mean birth body weight is 2707 +/- 693 grams (range: 1450-4100 grams) and the mean gestational age is 37.1 +/- 3.1 weeks (range: 31-41 weeks). The underlying clinical conditions include meconium aspiration syndrome (n = 8), perinatal asphyxia (n = 7), respiratory distress syndrome (n = 5), sepsis and/or pneumonia (n = 4), congenital diaphragmatic hernia (n = 3) and idiopathic persistent fetal circulation (n = 2). In addition to supportive medical care and correction of underlying clinical conditions, most of the patients receive vasodilator therapy (Tolazoline) and nonhyperventilation respirator management. The overall mortality rate is 27.6% (8/29). The duration on ventilator therapy in the survival group (9.3 +/- 8.6 days) is not significantly different from in the mortality group (6.0 +/- 7.1 days) (p = 0.13). There is also no statistically significant difference between these two groups both in the maximal alveolar-arterial oxygen tension difference (594 +/- 53 mmHg and 613 +/- 37 mmHg, p = 0.145) and in the maximal oxygenation index (49.7 +/- 29.6 and 61.1 +/- 36.9, p = 0.172) before vasodilator therapy. However, twenty-four hours after treatment, these two parameters change significantly with the former changes to 426 +/- 198 mmHg and 643 +/- 7 mmHg, respectively (p < 0.001), and the latter changes to 21.6 +/- 15.8 and 82.3 +/- 54.8, respectively (p < 0.001). Skin rash, gastrointestinal hemorrhage, hypotension and hyponatremia are the most common complications of Tolazoline therapy. Eight patients have pulmonary complications including pneumothorax (n = 5) and pulmonary interstitial emphysema (n = 3). Two patients develop chronic lung disease. Three patients have neurodevelopmental handicap. In conclusion, we achieve a survival rate of nearly 75% in PPHN mainly with the administration of Tolazoline therapy and the nonhyperventilation respirator approach. Further well-controlled and multicenter studies with newer treatment modalities are crucial for the improvement of survival of PPHN in Taiwan.

Treatment and outcome of congenital diaphragmatic hernia

BACKGROUND AND PURPOSE

Congenital diaphragmatic hernia (CDH) is a challenging condition and is associated with a high mortality rate; optimal therapy remains unclear. This retrospective study describes the clinical characteristics of treatment and outcome in 48 infants with CDH.

METHODS

Twenty-eight male (58%) and 20 female (42%) infants with CDH were treated from 1987 through 1998. The goals of the ventilator strategy were permissive hypercapnea (PaCO2 < or = 55 mm Hg) and avoidance of hyperventilation. Infants were initially ventilated with an intermittent mandatory rate of 40 to 60 per minute, peak inspiratory pressure of 20 to 25 cm H2O, and positive end-expiratory pressure of 5 cm H2O. High-frequency positive pressure ventilation was used if hypoxemia or severe hypercapnea (PaCO2 > 60 mm Hg) occurred. Most infants underwent repair after 3 days of age and only four infants underwent early repair within 24 hours of birth. A prophylactic chest tube was placed in the ipsilateral hemithorax postoperatively in all patients treated before 1996. The severity of respiratory distress was estimated by alveolar-arterial oxygen difference, oxygenation index, and alveolar-arterial ratio.

RESULTS

Forty-six patients presented with Bochdalek CDH, and two with Morgangni CDH. Antenatal diagnosis was made in 10 cases. Respiratory distress was the major manifestation and usually occurred immediately after birth. Six cases were diagnosed several months after birth and presented mainly with gastrointestinal symptoms. Eleven patients died before surgery and 37 patients underwent surgical repair. Two infants died postoperatively because of congestive heart failure and tension pneumothorax, respectively. The overall mortality rate was 27%. The major causes of mortality were severe respiratory failure, persistent pulmonary hypertension, pneumothorax, and associated anomalies.

CONCLUSION

Nearly 75% of patients in this series survived. This suggests that noninvasive respiratory care combined with delayed surgery may be an acceptable strategy for the treatment of CDH, and can be used in most medical institutions without equipment for extracorporeal membrane oxygenation therapy.