Sook Kyung Yum

Infant pertussis and household transmission in Korea.

A recent resurgence of pertussis has raised public health concerns even in developed countries with high vaccination coverage. The aim of this study was to describe the clinical characteristics of infant pertussis, and to determine the relative importance of household transmission in Korea. The multicenter study was prospectively conducted from January 2009 to September 2011. We identified the demographic and clinical data from these patients and performed the diagnostic tests for pertussis in their household contacts. Twenty-one patients with confirmed pertussis were included in the analysis. All infections occurred in infants younger than 6 months of age (mean age, 2.5 months) who had not completed the primary DTaP vaccination except for one patient. Infants without immunization history had a significant higher lymphocytosis and longer duration of hospital stay compared to those with immunization. All were diagnosed with PCR (100%), however, culture tests showed the lowest sensitivity (42.9%). Presumed source of infection in household contacts was documented in 85.7%, mainly parents (52.6%). Pertussis had a major morbidity in young infants who were not fully immunized. Household members were responsible for pertussis transmission of infants in whom a source could be identified. The control of pertussis through booster vaccination with Tdap in family who is taking care of young infants is necessary in Korea.

Impacts of therapeutic hypothermia on cardiovascular hemodynamics in newborns with hypoxic-ischemic encephalopathy: a case control study using echocardiography

Abstract Purpose: The effects of therapeutic hypothermia (TH) on hemodynamics in newborns with hypoxic-ischemic encephalopathy (HIE) were evaluated. Materials and methods: Thirty-two neonates (gestational age, 39.4 ± 1.3 weeks) who had TH for HIE and echocardiographic hemodynamic assessments during TH and post-TH period were studied. Gestational-age-matched 34 healthy neonates were enrolled for comparison. Results: During TH, patients had significantly decreased left ventricular cardiac output (LVCO), descending aorta blood flow (DABF), and DABF/LVCO ratio, and increased resistive index of DA compared to controls. Upper body blood flow (UBBF) remained unchanged but UBBF/LVCO ratio significantly increased during TH. Urine output decreased significantly during TH and increased after rewarming, and showed significant positive correlation with DABF/LVCO ratio. Sixteen patients (50%) showed hypoxic-ischemic (HI) lesions on brain magnetic resonance imaging (MRI) and had significantly increased UBBF/LVCO ratio during TH compared to patients without HI lesions. Patients with UBBF/LVCO ratio >55% had significantly higher risk of having HI lesions on brain MRI (odds ratio 13.0; 95% CI, 2.4–70.2). Conclusions: Decrease in cardiac output and descending aorta blood flow, and preferential cerebral redistribution of cardiac output along with an increase in systemic peripheral vascular resistance may affect systemic organ perfusion and cerebral metabolism.

Echocardiographic assessment of patent ductus arteriosus in very low birthweight infants over time: prospective observational study

Abstract Background: We aimed to determine the echocardiographic parameters that can predict the presence of patent ductus arteriosus (PDA) and haemodynamically significant ductus arteriosus (HSDA) at different time points. Methods: Echocardiogram was performed on postnatal days 3 and 7(D3-Echo and D7-Echo, respectively) in 71 very low birthweight infants with a median gestational age of 28.0 weeks. We first assessed the correlation between D3-Echo findings among infants with ductal patency and persistent ductal patency on D7-Echo. We subsequently assessed the correlation between D7-Echo findings and ultimate need for PDA treatment. Results: Forty-nine (69.0%) infants had ductal patency on D3-Echo, and 32(65.3%) of these had persistent PDA on D7-Echo. Twenty of the latter (62.5%) underwent PDA treatment at a median chronological age of 19 days. PDA treatment was significantly correlated with DA size and DA peak-systolic-to-end-diastolic velocity(S/D) ratio on D3- and D7-Echo. Receiver operating characteristic curve analysis revealed that DA size ≥2.040 mm and S/D ratio ≥2.016 had fair sensitivity, specificity, and predictive values for PDA treatment. Conclusion: The significance of different echocardiographic parameters associated with future ductal patency or HSDA depends on the time of assessment. DA size and S/D ratio on day 7 are two reliable indicators of the need for future PDA treatment.

Impact of histologic chorioamnionitis on pulmonary hypertension and respiratory outcomes in preterm infants

We aimed to evaluate the association between the presence of histologic chorioamnionitis (HC) and development of pulmonary hypertension (PH) during neonatal intensive care unit (NICU) stay. Data of preterm infants born at 32 weeks of gestation or less were reviewed. The development of PH and other respiratory outcomes were compared according to the presence of HC. Potential risk factors associated with the development of PH during NICU stay were used for multivariable logistic regression analysis. A total of 188 infants were enrolled: 72 in the HC group and 116 in the no HC group. The HC group infants were born at a significantly shorter gestational age and lower birthweight, with a greater proportion presenting preterm premature rupture of membrane (pPROM) > 18 h before delivery. More infants in the HC group developed pneumothorax (P = 0.008), and moderate and severe bronchopulmonary dysplasia (BPD; P = 0.001 and P = 0.006, respectively). PH in the HC group was significantly more frequent compared to the no HC group (25.0% versus 8.6%, P = 0.002). Based on a multivariable logistic regression analysis, birthweight (P = 0.009, odds ratio [OR] = 0.997, 95% confidence interval [CI] = 0.995–0.999), the presence of HC (P = 0.047, OR = 2.799, 95% CI = 1.014–7.731), and duration of invasive mechanical ventilation (MV) > 14 days (P = 0.015, OR = 8.036, 95% CI = 1.051–43.030) were significant factors. The presence of HC and prolonged invasive MV in infants with lower birthweight possibly synergistically act against preterm pulmonary outcomes and leads to the development of PH. Verification of this result and further investigation to establish effective strategies to prevent or ameliorate these adverse outcomes are needed.

Therapeutic hypothermia in infants with hypoxic–ischemic encephalopathy and reversible persistent pulmonary hypertension: short-term hospital outcomes

Abstract Aim: Neonatal hypoxic ischemic encephalopathy (HIE) patients are at times accompanied by persistent pulmonary hypertension (PPHN), which is by itself another risk factor of adverse outcomes. We aimed to assess the outcome of therapeutic hypothermia (TH) in these patients whom we managed to reverse the shunt flow, as they are expected to be at much higher risk of adverse neurodevelopmental outcome. Methods: We reviewed the medical records of 116 HIE infants (13 with PPHN and 103 without PPHN) who underwent TH between 2012 and 2016. We analyzed the short-term hospital outcomes and brain study results (electroencephalogram and magnetic resonance imaging) of TH in these patients. Results: While infants with PPHN were significantly more likely to be outborn or have meconium aspiration syndrome, and required a longer duration of inotrope and intensive care support, electroencephalographic and brain magnetic resonance findings did not significantly differ according to PPHN status. Conclusion: Based on our study, the hospital outcomes of infants with HIE accompanied by reversible PPHN who underwent TH were in general not significantly graver than those not accompanied by PPHN. Our results suggest that undergoing TH may be more beneficial in HIE infants with PPHN and the risks for possible adverse effects may not be as so high.

Changes in lactate dehydrogenase are associated with central gray matter lesions in newborns with hypoxic-ischemic encephalopathy

Abstract Purpose: Biomarkers may predict neurological prognosis in infants with hypoxic-ischemic encephalopathy (HIE). We evaluated the relationship between serum lactate dehydrogenase (LDH) and brain magnetic resonance imaging (MRI), which predicts neurodevelopmental outcomes, in order to assess whether LDH levels are similarly predictive. Materials and methods: Medical records were reviewed for infants with HIE and LDH levels were assessed on the first (LDH1) and third (LDH3) days following birth. Receiver operating characteristic curves were obtained in relation to central gray matter hypoxic-ischemic lesions. Results: Of 92 patients, 52 (56.5%) had hypoxic-ischemic lesions on brain MRI, and 21 of these infants (40.4%) had central gray matter lesions. LDH1 and LDH3 did not differ; however, the percentage change (ΔLDH%) was significantly higher in infants with central gray matter lesions (36.9% versus 6.6%, p = 0.006). With cutoffs of 187 (IU/L, ΔLDH) and 19.4 (%, ΔLDH%), the sensitivity, specificity, positive predictive value and negative predictive value were 71.4, 69.0, 40.5 and 89.1%, respectively. The relative risk was 5.57 (p = 0.001). Conclusion: Changes in serum LDH may be a useful biomarker for predicting future neurodevelopmental prognosis in infants with HIE.

Risk factor profile of massive pulmonary haemorrhage in neonates: the impact on survival studied in a tertiary care centre

Abstract Objective: Pulmonary haemorrhage (PH) in neonates is a fatal event leading to hazardous complications and even death. The aim of this study was to elucidate influential factors of the ultimate disease course that affect death or survival. Methods: Infants treated for PH in our institution from March 2009 to December 2013 were retrospectively reviewed. Infants transferred from other hospitals were excluded. Infants were grouped into two categories, deceased or survived at neonatal intensive care unit discharge. Information regarding perinatal history, initial management and laboratory results were obtained and analysed for each group. Results: Seventy infants fulfilled the inclusion criteria, 41 infants in the deceased group and 29 infants in the survived group. Overall, the infants in the deceased group displayed lower gestational age (27 and 1/7 ± 3.610 versus 29 and 3/7 ± 3.530 weeks, p = 0.009) and lower one-minute (2.342 ± 1.493 versus 4.035 ± 2.079, p < 0.001) and five-minute Apgar scores (2.342 ± 1.493 versus 4.035 ± 2.079, p < 0.001) and required aggressive resuscitation (p = 0.003) and a greater number of inotropes (2.195 ± 1.346 versus 1.069 ± 0.704, p < 0.001). Deceased infants were administered increased amounts of fluid during the first 24 h after birth (117.783 ± 32.325 versus 99.379 ± 17.728 mL/kg, p = 0.004). A relatively short prothrombin time impacted survival (p = 0.01), whereas platelet count was the only factor that significantly affected the time length from the onset of PH to death (p = 0.01). Conclusion: Infants with a lower gestational age in a compromised state are prone to die once PH develops. The initial management of fluid intake not to exceed the adequate limit is especially important in order to prevent PH-related deaths when correcting hypoalbuminemia and coagulopathy.

Evaluation of risk for graft-versus-host disease in children who receive less than the full doses of mini-dose methotrexate for graft-versus-host disease prophylaxis in allogeneic hematopoietic stem cell transplantation.

Purpose The use of cyclosporine and mini-dose methotrexate (MTX) is a common strategy for graft-versus-host disease (GVHD) prophylaxis in allogeneic transplants. We investigated whether patients who receive fewer than the planned MTX doses are at increased risk for GVHD. Methods The study cohort included 103 patients who received allogeneic transplants at the Department of Pediatrics of The Catholic University of Korea College of Medicine, from January 2010 to December 2011. MTX was administered on days 1, 3, 6, and 11 after transplant at a dose of 5 mg/m2 each. Within the cohort, 76 patients (74%) received all 4 doses of MTX [MTX(4) group], while 27 patients (26%) received 0-3 doses [MTX(0-3) group]. Results Although there was no difference in neutrophil engraftment between the 2 groups, platelet engraftment was significantly faster in the MTX(4) group (median, 15 days), compared to the MTX(0-3) group (median, 25 days; P=0.034). The incidence of grades II-IV acute GVHD was not different between the MTX(4) and MTX(0-3) groups (P=0.417). In the multivariate study, human leukocyte antigen mismatch was the most significant factor causing grades II-IV acute GVHD (P=0.002), followed by female donor to male recipient transplant (P=0.034). No difference was found between the MTX(4) and MTX (0-3) groups regarding grades III-IV acute GVHD, chronic GVHD, and disease-free survival. Conclusion Our results indicate that deviations from the full dose schedule of MTX for GVHD prophylaxis do not lead to increased incidence of either acute or chronic GVHD.

Perinatal prediction model for severe intraventricular hemorrhage and the effect of early postnatal acidosis

PurposeSevere acidosis is one of the strongest predictors of neurologic outcomes in full-term infants with suspected hypoxic-ischemic encephalopathy. However, the relative importance of acidosis as a predictor of outcomes in preterm infants is much less clear. The goals of the present study were to examine the association between postnatal acidosis and severe intraventricular hemorrhage (IVH) and to establish a new score model including acid-base status after birth for predicting the risk of this morbidity.MethodsThe study sample was very low birth weight (VLBW) infants in the Korean Neonatal Network (KNN) cohort registry, collected prospectively from January 2013 to December 2014. Infants with blood pH and base deficit (BD) values collected within the first hour after birth, and documentation of severe IVH, were included. Multivariate stepwise logistic regression analysis was used to determine the contribution of postnatal acidosis to predicting severe IVH in VLBW infants. In addition, a prediction model was developed.ResultsData from 2518 VLBW infants were analyzed. Infants with postnatal acidosis had a higher incidence of severe IVH. The clinical model plus blood BD values improved predictive performance, compared with models using only perinatal data or blood pH.ConclusionsA prediction model for severe IVH was developed using the KNN registry of VLBW infants. Immediate postnatal acidosis, defined based on blood BD, was associated with a higher-risk-adjusted incidence of severe IVH.

Expanded criteria for retinopathy of prematurity screening in moderately preterm infants: Single‐center pilot study

While developed countries seek to lower the gestational age and birthweight parameters in retinopathy of prematurity (ROP) screening, older, larger infants still develop ROP in other parts of the world. The aim of this study was therefore to define criteria to identify potential ROP developers who are outliers of the common screening range.