Echocardiographic Evaluation of Patent Ductus Arteriosus in Preterm Infants

The increased longitudinal basal-to-apical strain ratio in the right ventricular free wall is associated with neonatal pulmonary hypertension

It has been a challenging work to identify and assess neonatal pulmonary hypertension (PH). Right ventricular longitudinal strain (RVLS) is primarily used in evaluating right ventricular (RV) systolic function. This study aimed to investigate the association of the changes in segmental and global RVLS with neonatal PH, hoping to provide a new marker for indicating neonatal PH other than obtaining information on RV function. This was a cross-sectional study with 62 neonates, generally divided into PH and non-PH groups confirmed by echocardiography. For 30 infants later diagnosed with bronchopulmonary dysplasia (BPD), specific analysis was conducted by subdividing them into BPD with and without PH subgroups. Conventional echocardiography markers and the global and segmental RVLS were measured and compared. Their diagnostic performance in evaluating PH was analyzed. Regardless of grouping, the biventricular function of all infants was similar and in normal range. No significant difference was found in global strain parameters, either. In the case of PH, tricuspid regurgitant velocity (TRV), left ventricle systolic eccentricity index (LVsEI), and the basal-to-apical strain ratio (Ratio bas/api) of RV free wall (RVFW) were significantly higher (P < 0.001, P < 0.05, P < 0.05). By contrast, the magnitude of apical segmental strain reduced significantly (P < 0.05) and was significantly lower than that of basal segmental strain in BPD with PH subgroup (P = 0.024). The area under the curve values for Ratio bas/api was highest (0.846), followed by LVsEI (0.746) and apical segmental strain (0.272).

CONCLUSION

As a relatively standardized parameter, Ratio bas/api of RVFW was significantly higher in the case of neonatal PH with normal cardiac function and could be regarded as a new indicator for PH.

WHAT IS KNOWN

• It has been challenging work to diagnose neonatal pulmonary hypertension (PH), and conventional echocardiography has been widely applied, though it is not sufficient enough. • RV longitudinal strain (RVLS) is primarily used to assess RV systolic function, and its role in diagnosing PH was rarely considered.

WHAT IS NEW

• The basal-to-apical strain ratio (Ratio bas/api) of RV free wall increased significantly in all infants with PH regardless of causes. • As a relatively standardized parameter, Ratio bas/api could be regarded as a new indicator for diagnosing PH, apart from conventional echocardiographic parameters.

Doppler Ultrasonographic Assessment of Abdominal Aortic Flow to Evaluate the Hemodynamic Relevance of Left-to-Right Shunting Patent Ductus Arteriosus in Dogs

In this multicenter, prospective, observational study, abdominal aortic flow was examined with pulsed-wave Doppler ultrasound in dogs with a left-to-right shunting patent ductus arteriosus (PDA) and in apparently healthy dogs. Forty-eight dogs with a PDA and 35 controls were included. In the dogs with a PDA, 37/48 had hemodynamically significant PDAs (hsPDAs) while 11/48 had non-hsPDAs, based on the presence or absence of echocardiographic signs of left-sided volume overload, respectively. In 12 dogs (4/35 control dogs, 7/37 dogs with an hsPDA and 1/11 dogs with a non-hsPDA), the diastole was too short to visualize the end-diastolic flow. Antegrade end-diastolic flow was observed in 30/35 controls and 6/11 dogs with a non-hsPDA. Absent end-diastolic flow was observed in 1/35 control dogs and 3/11 dogs with a non-hsPDA. Retrograde end-diastolic flow was observed in 30/37 dogs with an hsPDA and 1/11 dogs with a non-hsPDA. Twenty-one dogs (15 with an hsPDA and 6 with a non-hsPDA) were reassessed after PDA closure, and, in 19/21, end-diastolic flow was visualized: 17/19 showed an antegrade flow, 1/19 an absent flow and 1/19 a retrograde flow. Sensitivity and specificity of retrograde end-diastolic flow for detection of hsPDAs were 100% and 90%, respectively. In conclusion, ultrasonographic assessment of abdominal aortic flow was feasible in dogs with PDA. However, end-diastolic flow was not always visualized. The presence of a retrograde end-diastolic flow was an accurate finding for discriminating hsPDAs and non-hsPDAs.

Relationship between Decrease in Urine Output following Treatment with Prostaglandin Inhibitors and PDA Closure

OBJECTIVE

Prostaglandin inhibitors are used for the treatment of patent ductus arteriosus (PDA) and they often transiently decrease the urine output (UO) due to prostaglandin inhibition in the renal vasculature. We hypothesized that preterm infants whose renal vasculature shows greater sensitivity to prostaglandin inhibitors are likely to have ductal tissue with greater sensitivity to the same. Our objective was to determine whether the decrease in UO following treatment of PDA with a prostaglandin inhibitor is associated with a higher probability of PDA closure.

STUDY DESIGN

In a prospective, proof-of-concept, cohort study, we enrolled 40 preterm neonates with hemodynamically significant PDA (hsPDA), being treated with a prostaglandin inhibitor. The key predictor, UO, was measured at baseline and daily until 72 hours. We repeated echocardiography daily until PDA closure or the end of treatment. The key outcome was PDA closure. We compared "PDA-closed" (n = 28) and "PDA-open" (n = 12) groups for change in UO from baseline.

RESULTS

The median (Q1, Q3) percent decrease in UO (figures rounded off to integers) was greater in the "PDA-closed" versus "PDA-open" group: from baseline to 0 to 24 hours [-45% (-55%, +0.04%) vs. -15% (-28%, +49%)]; baseline to 24 to 48 hours [-41% (-53%, +14%) vs. -3% (-25%, +62%), p = 0.03] and baseline to 48 to 72 hours [-33% (-49%, +32%) vs. +21% (-7%, +98%), p = 0.02]. Decrease in UO preceded PDA closure. The "PDA-closed" group had significantly greater weight loss, despite a greater decrease in UO. A decrease in UO of 27 and 17% by 24 to 48 hours and 48 to 72 hours, respectively, best predicted PDA closure.

CONCLUSION

A decrease in UO after treating hsPDA with a prostaglandin inhibitor is associated with successful closure of PDA.

KEY POINTS

· Prostaglandin inhibition causes both decrease in urine output and PDA closure following medical treatment. · The association between drug-induced decrease in urine output and PDA closure has been inadequately studied.. · Decrease in urine output after treatment with prostaglandin inhibitors increases the chances of PDA closure..

Hemodynamic evaluation of extremely low birth weight infants during the first 7 days of life

BACKGROUND AND AIM

We aimed to investigate the hemodynamic status of extremely low birth weight (ELBW) infants during the transitional period under intensive management.

METHODS

This retrospective cohort study analyzed left ventricular ejection fraction (LVEF), left ventricular end-systolic wall stress (ESWS), left ventricular internal dimension in diastole (LVIDd), and mean arterial pressure (MAP) of ELBW infants during their first week of life. Small for gestational age (SGA), histological chorioamnionitis (hCAM), severe intraventricular hemorrhage (IVH), and non-survival to discharge infants were compared to their counterparts.

RESULTS

Sixty-two infants (25.7 ± 2.1 weeks, 700.7 ± 165.4 g) were analyzed. MAP gradually increased. Median LVEF was 69.8 % on day 1, decreased to 62.7 % on day 2, then increased throughout the week. ESWS was lowest at birth, rose to 28.2 g/cm2 on day 2, and decreased on day 6. There were no significant changes in LVIDd. SGA infants had higher MAP throughout, higher LVEF on day 2 and 3, but lower LVEF on day 5 to 7. LVIDd was lower in hCAM group. Severe IVH group had a more significant drop in LVEF on day 2, higher ESWS, and a higher incidence of hemodynamic significant patent ductus arteriosus (hsPDA). Non-survival had lower LVIDd.

CONCLUSIONS

MAP increased gradually. Hemodynamic instability was observed in the first two days, with decreased LVEF and increased ESWS before stabilization. We observed an alteration in hemodynamic adaptation in SGA and hCAM infants. Severe IVH group experienced early hemodynamic instability and a higher incidence of hsPDA.

Superoxide dismutase for bronchopulmonary dysplasia in preterm infants

BACKGROUND

Free oxygen radicals have been implicated in the pathogenesis of bronchopulmonary dysplasia (BPD) in preterm infants. Superoxide dismutase (SOD) is a naturally occurring enzyme which provides a defense against such oxidant injury. Providing supplementary SOD has been tested in clinical trials to prevent BPD in preterm infants.

OBJECTIVES

To determine the efficacy and safety of SOD in the prevention and treatment of BPD on mortality and other complications of prematurity in infants at risk for, or having BPD.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, and three trials registers on 22 September 2022 together with reference checking, citation searching and contact with study authors to identify additional studies.

SELECTION CRITERIA

Randomized, quasi-randomized and cluster-randomized controlled trials (RCTs) where the participants were preterm infants who had developed, or were at risk of developing BPD, and who were randomly allocated to receive either SOD (in any form, by any route, any dose, anytime) or placebo, or no treatment.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were BPD defined as an oxygen requirement at 28 days, BPD defined as oxygen at 36 weeks' postmenstrual age, neonatal mortality, mortality prior to discharge, and BPD or death at 36 weeks' postmenstrual age. We reported risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CIs) for the dichotomous outcomes. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We included three RCTs (380 infants) on SOD administration in preterm infants at risk for BPD, and no studies in preterm infants with evolving BPD / early respiratory insufficiency. The evidence is very uncertain about the effect of SOD on BPD defined as an oxygen requirement at 28 days (RR 1.09, 95% CI 0.94 to 1.26; RD 0.06, 95% CI -0.05 to 0.16, 1 study, 302 infants; I2 for RR and RD not applicable), BPD defined as oxygen at 36 weeks' postmenstrual age (RR 0.96, 95% CI 0.72 to 1.29; RD -0.01, 95% CI -0.11 to 0.09, 2 studies, 335 infants; I2 for RR and RD = 0%), neonatal mortality (RR 0.98, 95% CI 0.57 to 1.68; RD -0.00, 95% CI -0.08 to 0.07, 2 studies, 335 infants; I2 for RR and RD = 0%), and mortality prior to discharge (RR 1.20, 95% CI 0.53 to 2.71; RD 0.04, 95% CI -0.14 to 0.23, 2 studies, 78 infants; I2 for RR and RD = 0%). No studies reported BPD or death at 36 weeks' postmenstrual age. The evidence is very uncertain about the effect of SOD on retinopathy of prematurity any stage (RR 0.95, 95% CI 0.78 to 1.15; RD -0.03, 95% CI -0.15 to 0.08, 2 studies, 335 infants; I2for RR = 0%, I2 for RD = 8%), and severe retinopathy of prematurity (ROP) (RR 0.97, 95% CI 0.57 to 1.65; RD -0.01, 95% CI -0.10 to 0.09, 1 study, 244 infants; I2 for RR and RD not applicable). No studies reported moderate to severe neurodevelopmental outcome at 18 to 24 months. Certainty of evidence was very low for all outcomes. We identified no ongoing trials.

AUTHORS' CONCLUSIONS

The evidence is very uncertain about the effect of SOD on BPD defined as an oxygen requirement at 28 days, BPD defined as oxygen at 36 weeks' postmenstrual age, neonatal mortality and mortality prior to discharge compared to placebo. No studies reported BPD or death at 36 weeks' postmenstrual age and need for supplemental oxygen. The evidence is very uncertain about the effect of SOD on retinopathy of prematurity any stage and severe retinopathy of prematurity. No studies reported moderate to severe neurodevelopmental outcome at 18 to 24 months. The effects of SOD in preterm infants has not been reported in any trial in the last few decades, considering that the most recent trial on SOD in preterm infants was conducted in 1997/1998, and no new studies are ongoing. In the light of the limited available evidence, new data from preclinical and observational studies are needed to justify the conduction of new RCTs. Observational studies might report how SOD is administered, including indication, dose and association with relevant outcomes such as mortality, BPD and long-term neurodevelopment.

Echocardiographic parameters predicting spontaneous closure of ductus arteriosus in preterm infants

Objective

To evaluate the value of echocardiographic parameters in predicting early spontaneous closure of ductus arteriosus in premature infants.

Methods

222 premature infants admitted to the neonatal ward of our hospital were selected, and patent ductus arteriosus was detected by echocardiography 48 h after birth. On the 7th day, whether the ductus arteriosus was closed naturally in this cohort was observed. The infants whose ductus arteriosus were not closed were identified as the PDA group (n = 109), and the other infants were included in the control group (n = 113). The echocardiographic parameters of the two groups of premature infants at 48 h after birth were single-factor statistically and Pearson correlation analyzed, and the parameters with statistically significant differences in single-factor analyzed were selected for multivariate logistic stepwise regression analysis.

Results

The ductus arteriosus shunt velocity and the pressure difference between the descending aorta and the pulmonary artery (ΔPs) in the PDA group were lower than those in the control group (P < 0.05). The pulmonary artery pressure (PASP) in the PDA group was higher than that in the control group (P < 0.05). According to the multivariate logistic stepwise regression analysis, only the maximum shunt velocity of ductus arteriosus was correlated with early spontaneous closure of ductus arteriosus in 48 h first echocardiographic parameters (P = 0.049). The receiver operating characteristic (ROC) curve indicates the optimal critical point of echocardiographic ductus arteriosus shunt velocity in premature infants 48 h after birth was 1.165 m/s.

Conclusion

Echocardiographic parameters are of great value in predicting the early spontaneous closure of ductus arteriosus in premature infants. In particular, the ductus arteriosus shunt velocity is correlated with the early spontaneous closure of ductus arteriosus.

Gentamicin in Neonates with Hemodynamically Significant Patent Ductus Arteriosus

Background

Gentamicin has been shown to cause vasodilation in preclinical studies. Hemodynamically significant patent ductus arteriosus (hsPDA) is a commonly observed congenital heart disorder in preterm neonates. Concomitant gentamicin theoretically shall delay the closure/result in nonclosure of ductus arteriosus (DA). Similarly, hsPDA can alter the pharmacokinetics of gentamicin and so trough gentamicin concentrations. We carried out the present study to evaluate the association between gentamicin use and closure of hsPDA (treated with acetaminophen) as well as the effect of hsPDA on trough concentrations.

Methods

This study was a prospective, observational study that included 60 neonates diagnosed with hsPDA by echocardiography and 102 neonates without hsPDA. Demographic details, size of DA as per echocardiography at the end of treatment with acetaminophen, gentamicin-dosing regimen, and trough concentrations were collected. Standard definitions were adhered in classifying the gestational age, birth weights, and size of DA. The numerical values are reported in median (range).

Results

Neonates with hsPDA had significantly lower daily doses of gentamicin [4.5 (2.5-10), 7 (3.2-13) mg; P < 0.001] but longer duration of therapy [8 (3-14), 5 (3-7) days; P < 0.001] than those without hsPDA in very preterm neonates. No significant differences were observed in the trough concentrations of gentamicin between the groups. No association was observed between gentamicin use and closure of DA. However, those with successful closure of DA received gentamicin for a longer duration [6 (3-10), 4 (3-14) days; P < 0.05] that was independent of acetaminophen duration and had received higher cumulative doses of gentamicin.

Conclusion

In conclusion, we observed a significantly longer duration of gentamicin therapy in neonates with hsPDA compared to those without hsPDA. No significant differences were observed in the rates of closure of DA with concomitant gentamicin administration and gentamicin trough concentrations.

Reopening of ductus arteriosus in idiopathic premature constriction or closure of ductus arteriosus: A case series

BACKGROUND

There is no consensus on managing pregnancy when the fetus is diagnosed with idiopathic premature constriction or closure of the ductus arteriosus (PCDA). Knowing whether the ductus reopens is valuable information for managing idiopathic PCDA. We conducted a case-series study to investigate the natural perinatal course of idiopathic PCDA and examined factors associated with ductal reopening.

METHODS

We retrospectively collected information about the perinatal course and echocardiographic findings at our institution, which, on principle, does not determine delivery timing based on fetal echocardiographic results. We also examined perinatal factors related to the reopening of the ductus arteriosus.

RESULTS

Thirteen cases of idiopathic PCDA were included in the analysis. The ductus reopened in 38% of cases. Among cases diagnosed in <  37 weeks of gestation, 71% reopened, which was confirmed seven days after diagnosis (interquartile range 4-7). Diagnosis earlier in gestation was associated with ductal reopening (p = 0.006). Two cases (15%) developed persistent pulmonary hypertension. No fetal hydrops or death occurred.

CONCLUSIONS

The ductus is likely to reopen when prenatally diagnosed before 37 weeks gestation. There were no complications due to our pregnancy management policy. In idiopathic PCDA, especially if the prenatal diagnosis is made before 37 weeks of gestational age, continuing the pregnancy with careful monitoring of the fetus's well-being is recommended.

Use of Cardio-Pulmonary Ultrasound in the Neonatal Intensive Care Unit

Cardiopulmonary ultrasound (CPUS), the combination of lung ultrasound (LUS) and targeted neonatal echocardiography (TnECHO)AA, may offer a more appropriate approach to the challenging neonatal cardiovascular and respiratory disorders. This paper reviews the possible use of CPUS in the neonatal intensive care unit (NICU).

The dilemma of feeding during the treatment of patent ductus arteriosus with oral ibuprofen in preterm infants ≤30 weeks of gestation-a randomized controlled trial

OBJECTIVES

To evaluate the effect of minimal enteral feeding (MEN) versus withholding feeding on time to reach full feeds during treatment of hs-PDA with oral ibuprofen in infants ≤30 weeks.

STUDY DESIGN

We performed a single-center, randomized control trial of 126 premature infants born ≤30 weeks gestation, <7 days of age with hs-PDA comparing continuation of MEN (n = 64) vs no feeding (n = 62) during treatment. The primary outcome was time to reach a feed volume of 150 ml/kg/day. Secondary outcomes included were episodes of feed intolerance, GI bleed, NEC and other comorbidities.

RESULTS

There was no difference in the time to reach full feeds - median age of 16 days in both groups (p = 0.573). Incidence of feed intolerance, NEC and other secondary outcomes were also similar in both groups.

CONCLUSIONS

Continuing MEN during treatment of hs-PDA with oral ibuprofen does not decrease time to reach full enteral feeds in very preterm infants.

Fluid and electrolyte management in preterm infants with patent ductus arteriosus

Optimal fluid management of preterm babies with suspected or confirmed diagnosis of patent ductus arteriosus (PDA) is frequently challenging for neonatal care physician because of paucity of clinical trials. There is wide variation in practice across neonatal units, resulting in significant impact on outcomes in Extremely Low Birth Weight (ELBW) babies with hemodynamically significant PDA. A delicate balance is required in fluid management to reduce mortality and morbidity in this population. The purpose of this review is to lay out the current understanding about fluid and electrolyte management in ELBW babies with hemodynamically significant PDA and highlight areas for future research.

Lung ultrasound score has better diagnostic ability than NT-proBNP to predict moderate-severe bronchopulmonary dysplasia

The N-terminal end of B-type natriuretic peptide (NT-proBNP) and lung ultrasound (LUS) score have been proven to be adequate early biomarkers of bronchopulmonary dysplasia (BPD) in preterm infants. Our aim was to study if the predictive capacity of each one is increased by analyzing them together. We included infants born before 32 weeks with NT-proBNP and LUS scores on the first day of life (DOL) and on the 3rd, 7th, and 14th DOL and compared the diagnostic ability for moderate-severe BPD (msBPD) of each biomarker and in combination. We also compared them with a multivariate model of msBPD using only clinical variables. The sample size was 133 patients, and twenty-seven (20%) developed msBPD. The LUS score on the 7th DOL had better performance than NT-proBNP at the same moment: area under the receiver operating characteristic curve (AUC) 0.83 (0.75-0.89) versus 0.66 (0.56-0.75), p = 0.003, without differences in the rest of the times studied. These values did not increase when using the combination of both. A multivariate regression model that included only clinical variables (birth weight and invasive mechanical ventilation (IMV) at the 7th DOL) predicted msBPD with the same AUC as after the addition of any of these biomarkers, neither together.

CONCLUSION

The LUS score is a better predictor of msBPD on the 7th DOL than NT-proBNP in preterm infants born before 32 weeks, although they have similar diagnostic accuracy on the 1st, 3rd, and 14th DOL. Neither of them, nor together, have a better AUC for msBPD than a clinical model with birthweight and the need for IMV at the 7th DOL.

WHAT IS KNOWN

• NT-proBNP and LUS score are early predictors of moderate-severe bronchopulmonary dysplasia (msBPD).

WHAT IS NEW

• The combination of both NT-proBNP and LUS score does not increase the predictive ability of each separately.

The perinatal factors that influence the excretion of fecal calprotectin in premature-born children

This study aimed to provide additional information on the influence of perinatal factors on fecal (f)-calprotectin values in preterm infants. Calprotectin was determined from the first spontaneous stool (analyzed on the Alegria device by using the enzyme-linked immunosorbent assay [ELISA] method) obtained from neonates at a mean age of 3.41 ± 2.44 days of life. We analyzed 114 subjects who had a body weight of 1847.67 ± 418.6 g and were born at a gestational age of 32.6 ± 2.43 weeks, without intestinal and other congenital anomalies or any diseases other than those related to premature birth. The values of f-calprotectin are in a positive correlation with female subjects, intrauterine growth restriction, significant ductus arteriosus, enteral feeding intolerance, postnatal prolonged use of broad-spectrum antibiotics, and values ​​of bicarbonates (analyzed in a sample of capillary arterial blood). Measurement of f-calprotectin in the first 7 days after birth can help to early detect the intestinal distress or early staging of necrotizing enterocolitis in premature infants.

Physiological fetal vascular shunts and failure to regress: what the radiologist needs to know

The fetal circulation is characterized by the presence of three physiological vascular shunts - the ductus arteriosus, the foramen ovale and the ductus venosus. Acting in concert, these shunts preferentially stream blood flow in a pattern that maximizes efficiency of blood oxygenation by the maternofetal unit. Shortly following the transition to extrauterine life, a quick and predetermined succession of events results in closure of these embryological structures with consequent establishment of postnatal vascular flow patterns. While this transition is often seamless, the physiological shunts of the fetus occasionally fail to regress. Such failure to regress can occur in isolation or in association with other congenital malformations. This failed regression challenges the circulatory physiology of the neonate and might have implications for the optimum functioning of several organ systems. When symptomatic, these shunts are treated. Interventions, when undertaken, might be medical, endovascular or surgical. The radiologist's role continues to expand in the assessment of these shunts, in providing a roadmap for treatment and in prompt identification of treatment-related complications. This review is to familiarize radiologists with the embryology, pre- and post-treatment imaging appearances, and associated complications of persistent fetal vascular shunts.

Impact of Medical Treatment of Hemodynamically Significant Patent Ductus Arteriosus on Cerebral and Renal Tissue Oxygenation Measured by Near-Infrared Spectroscopy in Very Low-Birth-Weight Infants

Background and objective: Hemodynamically significant patent ductus arteriosus (hsPDA) can cause ductal steal and contribute to poor outcomes in preterm infants. Near-infrared spectroscopy (NIRS) allows us to continuously evaluate regional tissue oxygenation (rSpO2) and perfusion changes in underlying organs. The aim of this study was to evaluate the effect of medical treatment for hsPDA on cerebral and renal rSpO2 in infants less than 32 weeks of gestational age, and older than 72 h of life. Materials and methods: Infants with a gestational age of <32 weeks with hsPDA were prospectively studied before and during medical treatment. Two-site (cerebral and renal) rSpO2 monitoring by NIRS was performed 1 h before treatment (T0) and 24 h (T1), 24−48 h (T2), 48−72 h (T3) after the infusion of the first drug dose. Results: A total of 21 infants were studied. The mean day of life at treatment initiation was 8.2 (SD, 2.75). The DA diameter, LA/Ao ratio, and resistive index in the anterior cerebral artery (RI ACA) were significantly lower after treatment (p < 0.05). There were no significant differences in cerebral rSpO2, cerebral fractional tissue oxygen extraction (FTOE), and SpO2 comparing different time points. A significantly higher renal SpO2 value was recorded at T2 as compared with T0 (75.0%, SD 4.9%, vs. 69.4%, SD 7.6%; p < 0.013), while for renal FTOE, a tendency to lower values at T2 was observed (0.18, SD 0.05, vs. 0.24, SD 0.09; p = 0.068). Conclusions: Late (later than 7 days postpartum) hsPDA medical treatment with paracetamol or ibuprofen completely closed the duct only in a small proportion of preterm infants, despite a statistically significant reduction in the DA diameter, LA/Ao ratio, and RI ACA. Continuous renal, not cerebral, NIRS measurements can help to anticipate the efficacy of medical treatment of hsPDA in preterm infants. Large-scale prospective studies are needed to ascertain that renal and cerebral NIRS can be used as a reliable tool for evaluating the effectiveness of medical treatment for hsPDA.

Assessing patent ductus arteriosus in preterm infants from standard neonatal intensive care monitoring

Monitoring patent ductus arteriosus (PDA) in premature infants is currently performed intermittently using echocardiography which requires considerable expertise. The aim of this pilot study was to investigate whether PDA status could be assessed from standard neonatal intensive care monitoring. Electrocardiography (ECG) and blood pressure (BP) waveforms were acquired from extremely preterm infants using standard neonatal monitors. We developed software using MATLAB to analyse ECG and BP waveforms and their interrelationships in terms of pulse transit time (PTT) and pulse wave velocity (PWV). The times from peak systolic BP to diastolic trough (BPFt) and from the diastolic trough to peak systolic BP (BPRt) were also calculated. PTT, BPFt and BPRt were normalised for heart rate (HR) termed NPTT, NBPFt and NBPRt, respectively. ECG, invasive aortic BP monitoring and echocardiography were performed in 14 preterm infants < 29 weeks' gestation in the first 3 days after birth. The median (range) birth weight of the infants was 0.90 (0.48-1.31) kg, gestation 26.6 (24.0-28.7) weeks, PDA diameter 1.6 (0.8-3.6) mm and mean BP 32 (16-40) mmHg. We found a significant positive correlation between PDA diameter and NPTT (r = 0.69, P = 0.007) as well as NBPFt (r = 0.65, P = 0.012) and NBPRt (r = 0.71, P = 0.005). No relationship was found between PDA diameter and pulse pressure.Conclusions: Interrelationships between ECG and BP traces as well as BP waveform time analysis are straightforward to measure and associated with PDA diameter. The results of this pilot study suggest that this approach may help provide biomarkers for continuous monitoring PDA diameter and function. What is Known: • Patent ductus arteriosus (PDA) in premature infants is associated with increased risk of developing chronic lung disease, necrotising enterocolitis and cerebral injury. • Currently PDA is assessed intermittently using echocardiography which requires considerable expertise and sometimes is not well tolerated by critically ill preterm infants. What is New: • Blood pressure (BP) and ECG waveform interrelation and BP trace time analysis, taking account of heart rate, relate to PDA diameter. • ECG and BP waveform phase difference as well as BP waveform time analysis may be useful in the continuous assessment of PDA function.

Development and Validation of a Nomogram for Predicting the Risk of Bell's Stage II/III Necrotizing Enterocolitis in Neonates Compared to Bell's Stage I

BACKGROUND

Patients with Bell's Stage II/III necrotizing enterocolitis (NEC) may have more severe presentations, higher rates of death, and more long-term complications than those with Bell's Stage I NEC, so the purpose of this article was to construct a nomogram model to distinguish Bell's stage II/III NEC early from Bell's Stage I NEC, which is critical in the clinical management of NEC.

PATIENTS AND METHODS

A total of 730 NEC newborns diagnosed from January 2015 to January 2021 were retrospectively studied. They were randomly divided into training and validation groups at the ratio of 7:3. A nomogram model for predicting NEC was developed based on all the independent risk factors by multivariate regression analysis. The model's performance was mainly evaluated through three aspects: the area under the curve (AUC) to verify discrimination, the Hosmer-Lemeshow test and calibration curve to validate the consistency, and decision curve analysis (DCA) to determine the clinical effectiveness.

RESULTS

Predictors included in the prediction model were gestational age (GA), birth weight (BW), asphyxia, septicemia, hypoglycemia, and patent ductus arteriosus (PDA). This nomogram model containing the above-mentioned six risk factors had good discrimination ability in both groups, and the AUCs were 0.853 (95% CI, 0.82-0.89) and 0.846 (95% CI, 0.79-0.90), respectively. The calibration curve and DCA confirmed that the nomogram had good consistency and clinical usefulness.

CONCLUSIONS

This individual prediction nomogram based on GA, BW, asphyxia, septicemia, hypoglycemia, and PDA served as a useful tool to risk-stratify patients with NEC, and can help neonatologists early distinguish Bell's stage II/III NEC early from Bell's Stage I NEC.

Functional morphometry to estimate the alveolar surface area using a premature baboon model

The main respiratory pathophysiological process following premature birth is the delayed or arrested alveolar development that translates to a smaller alveolar surface area (S_A). Histological morphometry is the gold standard method to measure the S_A but requires invasive tissue sampling or the removal of the whole organ for analysis. Alternatively, the S_A could be measured in living subjects by "functional morphometry" using Fick's first law of diffusion and noninvasive measurements of the ventilation to perfusion ratio (V̇a/Q̇). We herein aim to describe a novel functional morphometric method to measure S_A using a premature baboon model. We used both functional morphometry and postmortem histological morphometry to measure S_A in 11 premature baboons born at 135 days who received intensive care treatment for 14 days. For the calculation of the S_A by functional morphology, we measured the septal wall thickness using microscopy, the alveolar arterial oxygen gradient using concurrent measurements of arterial pressure of O₂ and CO₂, and pulmonary perfusion using echocardiography and integrated Doppler signals. The median [interquartile range (IQR)] S_A using functional morphometry was 3,100 (2,080-3,640) cm² and using histological morphometry was 1,034 (634-1,210) cm² (left lung only). The S_A measured by functional morphometry was not related to the S_A measured by histological morphometry. Following linear regression analysis, the V̇a/Q̇ significantly predicted the histologically measured S_A (R² = 0.659, P = 0.002). In conclusion, functional measurements of ventilation to perfusion ratio could be used to estimate the alveolar surface area in prematurely born baboons and the ventilation perfusion ratio was the main determinant of the alveolar surface area.NEW & NOTEWORTHY The main morphological characteristic of chronic respiratory disease in prematurely born infants is the impaired/arrested alveolar growth that corresponds to a smaller aggregated alveolar surface area (S_A). This decreased S_A might be the limiting factor later in life affecting exercise capacity and quality of life. There is paucity of sensitive, noninvasive biomarkers to monitor the evolution of neonatal respiratory disease. Our noninvasive functional morphometric S_A might help to bridge the gap between pathophysiology and clinical monitoring.

Predictive Tool for Closure of Ductus Arteriosus with Pharmacologic or Surgical Treatment in Preterm Infants

To construct a model with the indices obtained by echocardiography to predict whether patent ductus arteriosus (PDA) was required to be treated with pharmacologic treatment or surgical ligation, we performed a prospective observational study, including all neonates with gestational age ≤ 30 weeks and assessed the hemodynamics of PDA by serial daily echocardiography examination at postnatal age of 0-12 h, 24 h, 48 h, and 72 h, respectively. The infants were classified in two groups based on whether they were treated with non-steroidal anti-inflammatory drugs (NSAIDs) and/or surgical ligation to close the PDA from the second week after birth. We compared the echocardiographic indices between the two groups and utilized the indices to construct a model to predict which premature infants' PDA requires intervention. The results showed that a total of forty-two preterm infants were enrolled in the study. 15 (35.7%) preterms were in the intervention group and 27 (64.3%) preterms were in the non-intervention group. Compared with the non-intervention group, the intervention group had a higher proportion of left ventricular volume overload and systemic shunt effect. In addition, the combined indicators of PDA size/weight > 3.2 mm/kg and LA/Ao > 1.4 at postnatal age of 72 h had a highest value to predict whether PDA requires intervention. These findings denoted that serial daily echocardiographic assessment can be useful in predicting whether a PDA will be closed with NSAIDs and/or surgical ligation in preterm infants with gestational age ≤ 30 weeks.Trial registration Number: IRB No. 2018-IRB-073. Date: 2018/09/21, retrospectively registered.

Trans-catheter closure of large PDA in adult patients with Amplatzer device: case series

Ductus arteriosus is a physiological structure if not closed after birth, may lead to many complications. Today, trans-catheter closure of patent ductus arteriosus with Occluder devices is the preferred method. Surgical ligation is used only in certain cases such as large symptomatic patent ductus arteriosus in very small infants and premature babies; unfavourable structure of the duct or economic considerations. In this article, we described haemodynamic and morphological characteristics of five patients with large patent ductus arteriosus which were occluded with Amplatzer device.From 23 January, 2010 to 31 July, 2018, five patients referred to our clinic with large patent ductus arteriosus and pulmonary arterial hypertension for further evaluation. After assessing them with various diagnostic methods, we decided to close defect with ventricular septal defect Occluder device. Patients aged 21-44 years and one of them was male. Ductus closure was successfully done with ventricular septal defect Occluder device. Closure was successful for all of them but in one case, whose device was embolized to pulmonary artery after 24 hr and he underwent surgery.Trans-catheter closure of large patent ductus arteriosus in adult patients with pulmonary hypertension is feasible. Despite the fact that complications may occur even with the most experienced hands, the 'double disk' Amplatzer ventricular septal defect muscular Occluder could be advantageous in this setting.

Retrospective comparison of death or neurodevelopmental outcomes in extremely low birth weight preterm infants following different management options of haemodynamically significant patent ductus arteriosus

BACKGROUND

Optimal management of haemodynamically significant patent ductus arteriosus (HsPDA) in premature babies remains controversial. Our aim is to compare death and/or adverse neurodevelopmental outcomes in extremely low birth weight (ELBW) infants with HsPDA who were managed with conservative [C], medical [M] and/or surgical [S] treatment, with secondary aim to examine short-term morbidities among [S] and [C] groups. The study also compared outcomes in very low birth weight (VLBW) infants with HsPDA and non-HsPDA.

METHODS

A retrospective study of VLBW preterm infants born before 29 weeks in Singapore from 2007 to 2016 was conducted.

RESULTS

A total of 474 VLBW infants were admitted in NUH from 2007 to 2016. Infants aged between 24 + 0 and 28 + 6 weeks of gestation, weighing ≤1500 g and diagnosed with patent ductus arteriosus (PDA) were included in the study, of which 172 infants (124 HsPDA and 48 non-HsPDA) were analyzed. Among infants with HsPDA, 17 infants were managed with [C], 83 with [M] and 24 with [S]. Mortality was not increased regardless of the presence of HsPDA or treatment received. Infants with non-HsPDA were less likely to have isolated speech delay (p < 0.05), but not global developmental delay (GDD). No significant differences in neurodevelopmental outcomes such as hearing loss, cerebral palsy (CP) and speech delay were found. [M + S] infants were at a higher risk of developing chronic lung disease (CLD) (OR 6.83, p < 0.05) and short-term growth failure compared to [C] infants. They were significantly shorter and had a smaller head circumference at discharge (p < 0.05). [M + S] infants also had elevated creatinine compared to those in group [C] (81.1 ± 24.1 vs 48.3 ± 11.8 umol/L, p < 0.000).

CONCLUSIONS

Compared to conservative management, infants requiring [M + S] treatment for HsPDA were more likely to have short-term complications such as CLD, elevated creatinine, and poorer growth. Despite a more turbulent postnatal course, death and/or adverse neurodevelopmental outcomes were not worse in infants managed with [M + S].

Renal Oxygenation Measured by Near-Infrared Spectroscopy in Neonates

BACKGROUND

Acute kidney injury (AKI) affects approximately 30% of infants admitted to the neonatal intensive care unit (NICU), and increases mortality risk by 50%. Current diagnostic criteria (serum creatinine rise with oliguria) cannot detect early-onset AKI, as up to 50% of nephron damage may occur by the time these abnormalities present. Once AKI is established, clinical management is often ineffective; therefore, prevention is key. Near-infrared spectroscopy (NIRS) offers a feasible, noninvasive approach to continuously monitor renal oxygenation trends over time, serving as a surrogate marker for renal perfusion.

PURPOSE

To provide an overview of NIRS principles for measuring renal oxygenation, and to describe current evidence of how this technology is being used among infants admitted to the NICU relative to the prediction and identification of AKI.

METHODS

A comprehensive search of PubMed and CINHAL focused on renal NIRS studies in NICU preterm and term infants was conducted.

RESULTS

Findings from 34 studies were included. In term infants, reduced renal oxygenation correlated to invasive SvO2 monitoring, predicted survivability and AKI. In preterm infants, reduced renal oxygenation was associated with AKI in one study, yet contrasting findings were reported in those with patent ductus arteriosus, including those who received prostaglandin inhibitors. Normative data in all infants were sparse.

IMPLICATIONS FOR PRACTICE

Renal NIRS may offer a noninvasive measurement of kidney hypoperfusion that may precede conventional diagnostic measures.

IMPLICATIONS FOR RESEARCH

Normative data are lacking, the threshold for renal ischemia is not defined, and consensus guiding clinical treatment based on NIRS data is nonexistent.

A valuable echocardiographic indicator for the optimal tightness of bilateral pulmonary artery banding

OBJECTIVES

The optimal tightness of bilateral pulmonary artery banding (BPAB) is considered to balance not only systemic-to-pulmonary blood flow but also each pulmonary blood flow, which is still challenging. To achieve them, we adopt the end-diastolic velocity (EDV) to the peak systolic velocity (PSV) ratio at BPAB with intraoperative epicardial echocardiography. We evaluated the usefulness of the EDV to PSV ratio and the patient outcomes.

METHODS

34 patients underwent BPAB with this indicator and using a looped polytetrafluoroethylene suture. The PSV and the EDV to PSV ratio with echocardiography were measured in the intraoperative, early postoperative and late postoperative period. Lung perfusion scintigraphy was performed to quantify flow to each lung.

RESULTS

There were 3 early deaths (< 30 days). Two patients required re-BPAB due to hypoxia. The intraoperative EDV to PSV ratios in the right and left were almost equal (0.50 ± 0.07 versus 0.51 ± 0.06, P = 0.73). There was no significant difference in the right and left EDV to PSV ratios throughout the postoperative course. The right PSV was smaller than the left PSV due to the Doppler angle intraoperatively (2.78 ± 0.57 versus 3.02 ± 0.50, P = 0.030). In addition, the PSV changed significantly until the late postoperative period (P < 0.001). Lung perfusion scintigraphy revealed only two patients had perfusion abnormalities.

CONCLUSIONS

Our clinical outcomes are satisfactory with low early mortality and a low rate of re-BPAB. The EDV to PSV ratio can be a reliable indicator to assess flow distribution to each lung and may be a valuable adjunct to achieve balanced systemic to pulmonary flow.

Patent ductus arteriosus, systemic NT-proBNP concentrations and development of bronchopulmonary dysplasia in very preterm infants: retrospective data analysis from a randomized controlled trial

BACKGROUND

Patent ductus arteriosus (PDA) is a common complication in very preterm infants. It is known that there is an association between PDA and development of bronchopulmonary dysplasia (BPD) or death before the postmenstrual age (PMA) of 36 weeks, but this association remains one of the most controversial aspects of the problem. The study aimed to evaluate the relationship between PDA, serum NT-proBNP levels at 2-3 and 8-9 days of life, and BPD/death in very preterm infants.

METHODS

Data of 52 preterm infants with a gestational age < 32 weeks, chronological age < 72 h, and PDA diameter > 1.5 mm, enrolled in a randomized controlled trial, were used for the retrospective analysis. All patients underwent daily echocardiographic and two serum NT-proBNP measurements within the first 10 days after birth. Two groups of infants were formed retrospectively at PMA of 36 weeks depending on the outcome, BPD (n = 18)/death (n = 7) or survival without BPD (n = 27). Receiver operator characteristic (ROC) curve was used to evaluate the predictive performance of serum NT-proBNP levels for BPD/death occurrence.

RESULTS

The percentage of infants who received pharmacological treatment for PDA did not differ between the groups. Based on the area under the ROC curve, serum NT-proBNP levels on the 2-3 day of life (AUC = 0.71; 95% confidence interval (CI): 0.56-0.9; p = 0.014)) and on the 8-9 day of life (AUC = 0.76; 95% CI: 0.6-0.9; p = 0.002) could reliably predict BPD/death in very preterm infants who had PDA diameter > 1.5 mm in the first 72 h of life. Hemodynamically significant PDA (hsPDA) was significantly more often detected in newborns with BPD/death, however, treatment of infants with hsPDA did not reduce the incidence of BPD/death.

CONCLUSIONS

In very preterm infants with PDA > 1.5 mm at the age of 24-48 h, serum NT-proBNP concentration could reliably predict the development of BPD or death, regardless of the persistence of PDA, with the highest diagnostic value at 8-9 days.

TRIAL REGISTRATION

This study is registered in ClinicalTrials.gov - NCT03860428 on March 4, 2019.

Association between intrauterine growth restriction and patent ductus arteriosus: Use of a dichorionic twin pregnancy model

OBJECTIVE

To evaluate the association between intrauterine growth restriction (IUGR) and the incidence of fetuses with patent ductus arteriosus (PDA) and Hemodynamically significant PDA (Hs-PDA) in dichorionic twins (DC) with selective IUGR.

MATERIALS AND METHODS

This is an observational cohort study and retrospective case assessment, involved twins born at Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan between 2013 and 2018. DC twins with selective IUGR (sIUGR) were defined as the presence of a birth weight discordance of >25% and a smaller twin with a birth weight below the tenth percentile. PDA was diagnosed using echocardiography between postnatal day 3 and 7. Hs-PDA was defined as PDA plus increased pulmonary circulation, poor systemic perfusion, cardiomegaly, pulmonary edema, or hypotension requiring pharmacotherapeutic intervention.

RESULT

A total of 1187 twins were delivered during the study period, and 53 DC twins with selective IUGR were included in this study. DC twins with PDA have higher rate of preterm birth, lower gestational age of delivery, and lower mean birth weight of both twins compared with DC twins without PDA. In a comparison of the sIUGR twin with the appropriate for gestational age co-twin, both the incidences of PDA (28.30% vs. 7.55%, respectively; P = 0.003) and Hs-PDA (24.53% vs. 5.66%, respectively; P = 0.002) were higher in sIUGR fetuses than in the appropriate for gestational age co-twins. Small gestational age of delivery was the only variable to predict PDA and Hs-PDA [p = 0.002, Odds ratio = 0.57 (0.39-0.82), p = 0.009, Odds ratio = 0.71 (0.55-0.92), respectively].

CONCLUSION

An analysis of dichorionic twins with sIUGR indicated that IUGR increased the risk of PDA and hemodynamically significant PDA.

The effects of ductal size on the severity of pulmonary hypertension in children with patent ductus arteriosus (PDA): a multi-center study

INTRODUCTION

Patent ductus arteriosus (PDA) is a common acyanotic heart disease that presents with variable symptoms.

OBJECTIVES

This study is therefore aimed at determining the relationship between gender, age, and size of PDA and pulmonary hypertension. This study also seeks to determine the prevalence of elevated pulmonary artery systolic pressure in children with PDA.

PATIENTS AND METHODS

A descriptive study of children with patent ductus arteriosus was carried out from 2016 to 2020 in three institutions. The data were analysed with the IBM SPSS statistics for windows, version 20 (IBM Corp, Chicago) RESULT: The mean ductal size was 3.78 (2.39) mm, with a minimum of 1.0 mm and a maximum size of 10.0 mm. The mean ductal size for males, 4.02 (2.53) mm was comparable with that of the females, 3.61 (2.28) mm (Student T-test = 0.8, 0.4). The mean pulmonary artery systolic pressure (PASP) of the patients was 43.36 (24.46) mmHg. Also the mean PASP was comparable among the males and the females, 48.37 (26.69) mmHg versus 39.63 (22.16) mmHg (Student T-test = 1.81, p = 0.07). There was no correlation between age and PASP (correlation coefficient = 0.009, p = 0.92). Sixty point two percent (60.2%) (62/103) of children with PDA had pulmonary hypertension. The proportion of males with pulmonary hypertension, 48.39% (30/62) was comparable with that of the females, 51.61% (32/62) (Chi2 = 2.05, p = 0.15) and females are 1.8 times more likely to have pulmonary hypertension as males (odds ratio 1.81, 95% CI 0.8-4.1). There was a positive correlation between ductal size and PASP (Pearson correlation coefficient = 0.26, p value = 0.007). Those with moderate and large sized duct tend to have moderate and severe pulmonary hypertension respectively and this is statistically significant. Chi2 = 17.85, p = 0.007 CONCLUSION: The prevalence of pulmonary hypertension in children with PDA is 60.2%. Moderate and large size duct presents with moderate and severe pulmonary hypertension respectively. Females are 1.8 times more likely to have pulmonary hypertension than the males.

Intravenous acetaminophen (at 15 mg/kg/dose every 6 hours) in critically ill preterm neonates with patent ductus arteriosus: A prospective study

WHAT IS KNOWN AND OBJECTIVES

Acetaminophen has been increasingly used in treating patent ductus arteriosus (PDA) in preterm neonates. Variations were observed in the dosing regimen of acetaminophen across the studies. There is hardly any data available for a relatively higher dose of intravenous acetaminophen (15 mg/kg/dose every 6 hours) in the preterm population. We present here the results of a prospective study with this dose of intravenous acetaminophen for treating PDA in critically ill preterm neonates.

METHODS

Preterm neonates (≤37 weeks of gestational age) with haemodynamically significant PDA were enrolled. Intravenous acetaminophen at 15 mg/kg/dose every 6 hours was administered. Echocardiographic monitoring, liver and renal function tests were carried out. Standard definitions were adhered for defining acute kidney injury (AKI) and hepatotoxicity.

RESULTS

Fifty-five neonates were recruited. Following the first dose, less than half had their serum acetaminophen concentrations in the therapeutic range. Extreme preterm neonates were less likely to have a sustained therapeutic acetaminophen concentration after the first dose. Following multiple doses and at steady state, 97.2% and 98.8% respectively were in the therapeutic range. Forty-three (78.2%) neonates had successful closure of the ductus arteriosus of which 22 were extreme preterm, 17 were very preterm and 4 were late preterm neonates; and considering their birthweights, 21 were extremely low, 16 were very low and 6 were low birthweight categories. Ten neonates had elevated alanine aminotransferase levels with three in the low-to-moderate risk of hepatotoxicity category. Eight neonates had altered renal function tests indicating AKI.

WHAT IS NEW AND CONCLUSION

Intravenous acetaminophen at 15 mg/kg/dose every 6 hours was efficacious in 78.2% of the preterm neonates with PDA. We observed a lower incidence of hepatotoxicity, and AKI in the study population. No association was observed between the serum acetaminophen concentrations and PDA closure.

Management of Patent Ductus Arteriosus in Premature Infants in 2020

The patent ductus arteriosus (PDA) is the most commonly found cardiac condition in neonates. While there have been several studies and thousands of publications on the topic, the decision to treat the PDA is still strongly debated among cardiologists, surgeons, and neonatologists. This is in part due to the shortage of long-term benefits with the interventions studied. Practice variations still exist within sub-specialties and centers. This article briefly summarizes the history, embryology and histology of the PDA. It also succinctly discusses the hemodynamic significance of a PDA which builds the framework to review all the available literature on PDA closure in premature infants, though not a paradigm shift just yet; it introduces transcatheter PDA closure (TCPC) as a possible armament to the clinician for this age-old problem.

Predictive Value of Blood N-Terminal Pro-Brain Natriuretic Peptide Concentrations for Early Patent Ductus Closure in Very Preterm Infants

Objectives

It has been shown that blood concentrations of NT-proBNP may be useful in identifying preterm infants at risk of hemodynamically significant patent ductus arteriosus and its complications. The aim of the study was to assess predictive value of serum NT-proBNP levels for early ductus arteriosus (DA) closure in very preterm newborns.

Methods

Fifty-two infants <32 weeks’ gestation aged <72 hours with patent ductus arteriosus (PDA) diameter >1.5 mm were involved in a randomized study. Twenty-seven (52%) of them were treated with ibuprofen or paracetamol starting within the first 3 days of life. Expectant management was applied to 25 (48%) infants. All patients underwent planned echocardiographic (daily) and two serum NT-proBNP measurements within the first 10 days after birth. Depending on the DA closure within the first 10 days of life, 2 groups of patients were formed retrospectively, with closed (n = 30) or patent (n = 22) DA by this age.

Results

In the first 10 days of life, DA closure occurred in 19 (70%) treated infants and in 11 (44%) infants managed expectantly (p > 0,05). Initial concentrations of NT-proBNP were significantly higher in infants that had patent ductus arteriosus (PDA) at 10 days of life. By the eighth day, median NT-proBNP values in both groups significantly decreased but remained considerably higher in newborns with PDA. NT-proBNP serum concentrations on the second day of life could reliably predict DA closure within the first 10 days after birth in treated babies (the AUC was significant 0.81 [95% CI: 0.58–1.03], p < 0.05) but not in infants who were managed expectantly.

Conclusions

Serum NT-proBNP concentrations on the second day of life could reliably predict early PDA closure in treated but not in expectantly managed very preterm infants.

Oxygen saturation and perfusion index screening in neonates at high altitudes: can PDA be predicted?

Screening critical congenital heart disease in neonates with 24-48 h of age could be made by oxygen saturation determination. Perfusion index may be used as an adjunct to pulse oximetry screening to detect non-cyanotic critical congenital heart disease cases such as a left heart outflow obstruction. We evaluate the results of combined screening for oxygen saturation and peripheral perfusion index at high altitudes. The study included 501 neonates older than gestational week 35. The mean oxygen saturation was lower than at sea level, and the screening test was positive in a total of 21 (4.2%) babies. Critical congenital heart diseases were not detected in any patient. A total of 10 (2%) babies were detected with PDA, nine (1.8%) of whom recorded a positive screening test. The prevalence of PDA was significantly higher in the positive screening test group when compared with those who underwent echocardiography due to clinical findings.Conclusion: The median peripheral perfusion index at high altitude was not lower than at sea level, while the mean oxygen saturation, in contrast, was lower than at sea level. The low partial oxygen pressure found at high altitudes leads to a variation in postnatal adaptation and an increased prevalence of PDA. Accordingly, oxygen saturation screening may serve to identify babies with PDA at high altitudes. What is Known: • Oxygen saturation is known to be low at high altitudes, and thus the rates of false positivity are high when screening for critical congenital heart disease. • High altitudes are also associated with an increased prevalence of simple congenital heart disease. What is New: • The peripheral perfusion index at high altitude is not lower than at sea level. • The prevalence of PDA is significantly higher in those with false positive screening results.

Caffeine versus aminophylline in combination with oxygen therapy for apnea of prematurity: A retrospective cohort study

The present study was conducted to investigate the clinical significance of caffeine and aminophylline in the treatment of premature infants with apnea under varying conditions of oxygen (O2) delivery. The clinical data of 120 premature infants with apnea treated with oxygen therapy and either caffeine citrate (20 mg/kg/day; n=77) or aminophylline (10 mg/kg/day; n=43) were retrospectively examined. The therapeutic performance of the drugs after the completion of the treatment was evaluated primarily according to the risk of recurrent episodes of apnea, the changes in the duration and concentration of inhaled O2 and the incidence of complications. In contrast to aminophylline, caffeine treatment significantly reduced the duration of O2 inhalation and the inhaled O2 concentration in the infants treated with mechanical ventilation or O2 delivery devices (P<0.05). Treatment with caffeine also decreased the incidence of recurrent apnea events and complications in the investigated population (P<0.05 or P<0.01). Caffeine performs better than aminophylline in the treatment of premature infants with apnea under different conditions of O2 delivery. The therapeutic performance of caffeine is achieved primarily via improving the efficacy of supplemental O2 and reducing the incidence of complications.

Effect of Nonintervention vs Oral Ibuprofen in Patent Ductus Arteriosus in Preterm Infants: A Randomized Clinical Trial

IMPORTANCE

Persistent patent ductus arteriosus (PDA) in preterm infants is associated with increased mortality and respiratory morbidities, including bronchopulmonary dysplasia (BPD). Despite recent increasing use of noninterventional approaches, no study to our knowledge has yet directly compared the nonintervention vs pharmacologic treatment for mediating PDA closure for decreasing mortality and preventing BPD.

OBJECTIVE

To determine the noninferiority of nonintervention vs oral ibuprofen treatment for PDA in decreasing BPD incidence or death in very preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, placebo-controlled, noninferiority clinical trial was conducted on preterm infants (gestational age [GA] 23-30 weeks) with hemodynamically significant PDA (ductal size >1.5 mm plus respiratory support) diagnosed between postnatal days 6 and 14. Participants included 383 infants screened between July 24, 2014, and March 15, 2019.

INTERVENTIONS

Infants were stratified by GA and randomly assigned (1:1) to receive either oral ibuprofen (initial dose of 10 mg/kg followed by a 5-mg/kg dose after 24 hours and a second 5-mg/kg dose after 48 hours) or placebo.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD or death; the secondary outcomes included major morbidities and ductal closure rates. Per-protocol analysis was used.

RESULTS

Among 383 infants screened for participation, 146 infants were randomly assigned, with 72 in the nonintervention and 70 in the ibuprofen treatment group in the final analyses. The PDA closure rate at 1 week after randomization was significantly higher with ibuprofen (11 [34%]) than nonintervention (2 [7%]) in infants at GA 27 to 30 weeks (P = .007); however, the findings were not significant at GA 23 to 26 weeks (ibuprofen, 3 [8%] vs nonintervention, 1 [2%], P = .34). In addition, the ductal closure rates before hospital discharge (ibuprofen, 62 [89%] vs nonintervention, 59 [82%], P = .27) and device closure (ibuprofen, 2 [3%] vs nonintervention, 4 [6%], P = .40) were not significantly different between the 2 groups. The nonintervention approach was noninferior to ibuprofen treatment in terms of BPD incidence or death (nonintervention, 44%; ibuprofen, 50%; 95% CI, -0.11 to 0.22; noninferiority margin -0.2; P = .51). One infant in the ibuprofen arm received oral ibuprofen backup rescue treatment owing to cardiopulmonary compromise refractory to conservative management, and another infant in the ibuprofen group received surgical ligation; none of the infants in the placebo group received backup treatment.

CONCLUSIONS AND RELEVANCE

Nonintervention showed noninferiority compared with ibuprofen treatment in closing of hemodynamically significant PDA and reduction of BPD or death. The noninferiority of nonintervention over ibuprofen might be attributable to the low efficacy of oral ibuprofen for closing PDA, especially in infants born at 23 to 26 weeks' gestation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02128191.

Neonatal functional echocardiography

PURPOSE OF REVIEW

The role of echocardiography has dramatically changed over the past decade and use of functional echocardiography has become increasingly popular among neonatologists and pediatric intensivists in making clinical decisions in sick infants and children. The purpose of this review is to outline the current capabilities and limitations of functional echocardiography, best practices for its clinical application, and evidence for its utility.

RECENT FINDINGS

Functional echocardiography can provide direct assessment of hemodynamics at bedside and can be used as a modern hemodynamic monitoring tool in the neonatal intensive care unit. It is now being regarded as a useful extension to the clinical examination and other monitoring tools in the critically ill infant. The anatomic, physiological, and hemodynamic information functional echocardiography provides can be used in targeting specific interventions and evaluating response to treatment.

SUMMARY

This review article is focused on an overview of the most common applications of functional neonatal echocardiography also called targeted neonatal echocardiography or neonatologist performed echocardiography. It will review assessment of hemodynamics and cardiac function in neonatal hypotension and shock, suspected patent ductus arteriosus, suspected persistent pulmonary hypertension of the newborn with evaluation of pulmonary artery pressure and assessment of pericardial effusion. It will also emphasize the specific requirements for the practice and training of functional neonatal echocardiography.

Echocardiographic predictors of acute kidney injury in neonates with a patent ductus arteriosus

OBJECTIVE

To investigate acute kidney injury (AKI) in neonates with a patent ductus arteriosus (PDA) including incidence, risk factors, and possible correlations between PDA-related echocardiographic measurements and AKI incidence.

STUDY DESIGN

We conducted a single-center retrospective cohort study of infants admitted to the neonatal intensive care unit with a diagnosis of a PDA between July 2015 and July 2017. Infants were evaluated for development of AKI based on the KDIGO criteria and a multivariable logistic regression analysis was performed.

RESULTS

A total of 142 neonates with moderate or large PDAs were included, 43 (30%) developed AKI. Patients who developed AKI had longer length of stay, lower birth weights, lengths, and gestational ages. No echocardiographic measurements were predictive of an increased risk for developing AKI.

CONCLUSION

There are no significant differences in commonly measured echocardiographic markers of PDA hemodynamic significance in neonates who develop AKI.

Aortic sinus aneurysm communicating with the main pulmonary artery, and a concurrent patent ductus arteriosus, in a dog

This is the first report of an aortic sinus aneurysm with a communication to the main pulmonary artery, resulting in left-to-right shunting, diagnosed in vivo in a dog. There was also a second left-to-right shunt through a patent ductus arteriosus. Computed tomography (CT) angiography was used to confirm both congenital anomalies and assess the relative contributions of the two left-to-right shunts to left-sided volume overload.

The effect of patent ductus arteriosus on coronary artery blood flow in premature infants: a prospective observational pilot study

OBJECTIVE

To compare coronary flows between premature infants with and without hemodynamically significant patent ductus arteriosus (hsPDA) and to determine if coronary flow is influenced by medical PDA treatment.

DESIGN

Prospective, observational pilot study. Forty-three infants <32 weeks gestation underwent echocardiography when routinely indicated. Study group included infants with hsPDA requiring treatment. Comparison groups included infants with nonsignificant PDA and infants without PDA.

RESULTS

The study group (n = 13), compared with the comparison groups with nonsignificant PDA (n = 12) and without PDA (n = 18) had higher troponin levels (p = 0.003 and 0.004, respectively). In infants with hsPDA compared with infants with no PDA there was a significant increase in myocardial oxygen demand and decrease in left main coronary artery flow, with nonsignificant increase in cardiac output.

CONCLUSIONS

Decrease in coronary artery flows and higher troponin values may suggest a "steal effect," not allowing to meet the elevated myocardial oxygen demand in infants with hsPDA.

Platelet Transfusion for PDA Closure in Preterm Infants: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Thrombocytopenia is associated with late closure of patent ductus arteriosus (PDA). There are few studies evaluating platelet transfusions to treat PDA. We compared liberal platelet-transfusion criteria (to maintain a platelet count >100 000 per µL) versus standard criteria achieve earlier PDA closure among thrombocytopenic preterm neonates (<35 weeks' gestation) with hemodynamically significant PDA (hs-PDA) presenting within the first 2 weeks of life.

METHODS

Thrombocytopenic (<100 000 per µL) preterm neonates with hs-PDA were enrolled and randomly allocated to the liberal and standard transfusion groups: 22 in each arm. They underwent echocardiography daily until closure of PDA, completion of 120 hours follow-up, or death. All subjects received standard cotreatment with nonsteroidal antiinflammatory drugs. Primary outcome of time to PDA closure was compared by survival analysis. Multivariate Cox proportional hazard regression was performed with randomization group, baseline platelet count, gestational age, and age at enrollment as predictor variables.

RESULTS

Median time to PDA closure was 72 (95% confidence interval [CI] 55.9-88.1) versus 72 (95% CI 45.5-98.4) hours in the liberal versus restrictive transfusion groups, respectively (unadjusted hazard ratio 0.88 [95% CI 0.4-1.9]; P = .697). Despite adjusting for potential confounders, there was no significant difference in time to PDA closure. In the liberal transfusion group, 41% of infants had any grade of intraventricular hemorrhage compared with 4.5% in the restrictive group (P = .009).

CONCLUSIONS

Attempting to maintain a platelet count >100 000 per µL by liberally transfusing platelets in preterm thrombocytopenic neonates with hs-PDA does not hasten PDA closure.

Association between Furosemide Exposure and Patent Ductus Arteriosus in Hospitalized Infants of Very Low Birth Weight

OBJECTIVE

To evaluate the association between furosemide exposure and patent ductus arteriosus (PDA) in a large, contemporary cohort of hospitalized infants with very low birth weight (VLBW).

STUDY DESIGN

Using the Pediatrix Medical Group Clinical Data Warehouse, we identified all inborn infants of VLBW <37 weeks of gestation discharged from the neonatal intensive care unit after the first postnatal week from 2011 to 2015. We defined PDA as any medical (ibuprofen or indomethacin) or surgical PDA therapy. We collected data up to the day of PDA treatment or postnatal day 18 for infants not diagnosed with PDA. We performed multivariable logistic regression to evaluate the association between PDA and exposure to furosemide.

RESULTS

We included 43 576 infants from 337 neonatal intensive care units, of whom 6675 (15%) underwent PDA treatment. Infants with PDA were more premature and more often exposed to mechanical ventilation and inotropes. Furosemide was prescribed to 4055 (9%) infants. On multivariable regression, exposure to furosemide was associated with decreased odds of PDA treatment (OR 0.72; 95% CI 0.65-0.79). Increasing percentage of days with furosemide exposure was not associated with PDA treatment (OR 1.01; 95% CI 0.97-1.06).

CONCLUSIONS

Furosemide exposure was not associated with increased odds of PDA treatment in hospitalized infants of VLBW. Further studies are needed to characterize the efficacy and safety of furosemide in premature infants.

Diagnosis and Management of Patent Ductus Arteriosus

Preterm infants are at increased risk for patent ductus arteriosus (PDA). Prolonged exposure to PDA may be deleterious and has been associated with neonatal morbidity and mortality. Although the molecular mechanisms underlying regulation of postnatal ductus arteriosus closure are not fully understood, clinical experience and research trials have informed recent changes in PDA management strategies and refocused treatment strategies on smaller subsets of infants who require intervention. This review examines current diagnostic and management approaches to PDA in preterm neonates.

Echocardiographic Evaluation of Ventricular Function-For the Neonatologist and Pediatric Intensivist

In the neonatal and pediatric intensive care setting, bedside cardiac ultrasound is often used to assess ventricular dimensions and function. Depending upon the underlying disease process, it is necessary to be able to evaluate the systolic and diastolic function of left and or right ventricles. The systolic function of left ventricle is mostly assessed qualitatively on visual inspection "eye-balling" and quantitatively by measuring circumferential fraction shortening or calculating the ejection fraction by Simpson's planimetry. The assessment of left ventricular diastolic function relies essentially on the mitral valve and pulmonary venous Doppler tracings or tissue Doppler evaluation. The right ventricular particular shape and anatomical position does not permit to use the same parameters for measuring systolic function as is used for the LV. Tricuspid annular plane systolic excursion (TAPSE) and S' velocity on tissue Doppler imaging are more often used for quantitative assessment of right ventricle systolic function. Several parameters proposed to assess right ventricle systolic function such as fractional area change, 3D echocardiography, speckle tracking, and strain rate are being researched and normal values for children are being established. Diastolic function of right ventricle is evaluated by tricuspid valve and hepatic venous Doppler tracings or on tissue Doppler evaluation. The normal values for children are pretty similar to adults while normal values for the neonates, especially preterm infants, may differ significantly from adult population. The normal values for most of the parameters used to assess cardiac function in term neonates and children have now been established.

Echocardiographic Evaluation of Transitional Circulation for the Neonatologists

The hemodynamic changes during the first few breaths after birth are probably the most significant and drastic adaptation in the human life. These changes are critical for a smooth transition of fetal to neonatal circulation. With the cord clamping, lungs take over as the source of oxygenation from placenta. A smooth transition of circulation is a complex mechanism and primarily depends upon the drop in pulmonary vascular resistance (PVR) and increase in systemic vascular resistance (SVR). Understanding the normal transition physiology and the adverse adaptation is of utmost importance to the clinicians looking after neonates. It may have a significant influence on the presentation of congenital heart defects (CHDs) in infants. Bedside echocardiography may help in understanding the transition physiology, especially the hemodynamic changes and shunting across ductus arteriosus and foramen ovale, and it may play an important role in making judicious clinical decisions based upon the altered physiology.