Echocardiographic assessment of patent ductus arteriosus shunt flow pattern in premature infants

The Bronchopulmonary Dysplasia score: A predictive model for bronchopulmonary dysplasia or death in high-risk preterm infants

AIM

Progressive respiratory deterioration in infants at high risk of bronchopulmonary dysplasia (BPD) is associated with patent ductus arteriosus (PDA) exposure. This study aimed to design an early predictive model for BPD or death in preterm infants using early echocardiographic markers and clinical data.

METHODS

Infants born with gestational age (GA) ≤ 29 weeks and/or birth weight (BW) < 1500 g at Cork University Maternity Hospital, Ireland were retrospectively evaluated. Those with echocardiography performed between 36 h and 7 days of life were eligible for inclusion. Exclusion criteria were pulmonary hypertension and major congenital anomalies. The primary outcome was a composite of BPD and death before discharge.

RESULTS

The study included 99 infants. A predictive model for the primary outcome was developed, which included three variables (BW, Respiratory Severity Score and flow pattern across the PDA), and yielding an area under the curve of 0.98 (95% CI 0.96-1.00, p < 0.001). Higher scores were predictive of the primary outcome. A cut-off of -1.0 had positive and negative predictive values of 89% and 98%, and sensitivity and specificity of 98% and 88%, respectively.

CONCLUSION

Our prediction model is an accessible bedside tool that predicts BPD or death in premature infants.

Hemodynamic evaluation in preterm infants using ultrasonic cardiac output monitor (USCOM)

We aimed to establish reference ranges for USCOM parameters in preterm infants, determine factors that affect cardiac output, and evaluate the measurement repeatability. This retro-prospective study was performed at Fondazione IRCCS San Gerardo dei Tintori, Monza, Italy. We included infants below 32 weeks of gestational age (GA) and/or 1500 g of birth weight (BW). We excluded infants with congenital heart diseases or hemodynamic instability. Measurements were performed at 3 ± 1, 7 ± 2, and 14 ± 2 postnatal days. We analyzed 204 measurements from 92 patients (median GA = 30.57 weeks, BW = 1360 g). The mean (SD) cardiac output (CO) was 278 (55) ml/min/kg, cardiac index (CI) was 3.1 (0.5) L/min/m2, and systemic vascular resistance (SVRI) was 1292 (294) d*s*cm-5/m2. CO presented a negative correlation with postmenstrual age (PMA), while SVRI presented a positive correlation with PMA. The repeatability coefficient was 31 ml/kg/min (12%).  Conclusion: This is the first study describing reference values for USCOM parameters in hemodynamically stable preterm infants and factors affecting their variability. Further studies to investigate the usefulness of USCOM for the longitudinal assessment of patients at risk for cardiovascular instability or monitoring the response to therapies are warranted. What is Known: • The ultrasonic cardiac output monitoring (USCOM) has been widely used on adult and pediatric patients and reference ranges for cardiac output (CO) by USCOM have been established in term infants. What is New: • We established reference values for USCOM parameters in very preterm and very-low-birth-weight infants; the reference ranges for CO by USCOM in the study population were 198-405 ml/kg/min. • CO normalized by body weight presented a significant negative correlation with postmenstrual age (PMA); systemic vascular resistance index presented a significant positive correlation with PMA.

Hemodynamic simulation of complete transposition of the great arteries for optimal treatment strategies based on its circulatory physiology

Our study aimed to elucidate the role of different shunts and provide novel insights into optimal treatment approaches for complete transposition of the great arteries (TGA), which is characterized by unique and complicated circulatory dynamics. We constructed a computational cardiovascular TGA model and manipulated cardiovascular parameters, such as atrial septal defect (ASD) and patent ductus arteriosus (PDA) sizes, to quantify their effects on oxygenation and hemodynamics. In addition, ASD flow patterns were investigated as innovative indications for balloon atrial septostomy (BAS). Our model of TGA with an intact ventricular septum (TGA-IVS) showed that a large ASD can achieve sufficient mixing for survival without PDA, and the presence of PDA is detrimental to oxygen delivery. A treatment strategy for TGA-IVS that enlarges the ASD as much as possible by BAS and PDA closure would be desirable. In TGA with a ventricular septal defect (TGA-VSD), the VSD allows for higher oxygenation and reduces the detrimental effects of PDA on systemic circulation. In TGA-VSD, both strategies of enlarging the ASD by BAS with a closed PDA and adjusting the PDA in response to pulmonary vascular resistance (PVR) reduction without BAS may be effective. The simulated ASD flow patterns showed that the sharp peak left-to-right flow pattern in systole (σ-wave) reflected the hemodynamically significant ASD size, independent of PDA, VSD, and PVR. The ASD flow pattern visualized by Doppler echocardiography provides clinical insights into the significance of an ASD and indications for BAS, which are not readily apparent through morphological assessment.NEW & NOTEWORTHY Complete transposition of the great arteries (TGA) represents complex and unique circulation that is dependent on blood mixing through multiple interacting shunts. Consequently, the role of each shunt and the treatment strategy remain unclear. We developed a mathematical model of TGA circulation, revealing the significant influence of atrial septal defect (ASD) on oxygenation and hemodynamics. The blood flow pattern through the ASD reflects its hemodynamic impact and helps determine treatment strategies.

Early Echocardiographic Predictors of Eventual Need for Patent Ductus Arteriosus Treatment: A Retrospective Study

OBJECTIVE

Hemodynamically significant patent ductus arteriosus (hsPDA) in preterm neonates is associated with end-organ injury including intraventricular hemorrhage. Early treatment may reduce morbidities but may result in overtreatment. This study aimed to examine the association between commonly obtained echocardiographic markers within the first 12 hours of life and eventual treatment of an hsPDA.

STUDY DESIGN

Patients with <32 weeks' gestational age had blinded echocardiograms done within the first 12 hours of life as part of research protocols. Subsequent treatment of the patent ductus arteriosus (PDA) was determined by the clinical team independent of echocardiogram results. t-tests and chi-square tests were done for continuous data and categorical outcomes. A receiver operating curve was created to optimize cutoff values.

RESULTS

 Among 199 neonates studied (mean time of echocardiogram 6.7 h after birth), those needing PDA treatment had higher left ventricular output (LVO), right ventricular output (RVO), and superior vena cava (SVC) flow (p-values 0.007, 0.044, and 0.012, respectively). Cutoffs for predicting PDA treatment were LVO > 204 mL/kg/min (63% sensitivity, 66% specificity), RVO > 221 mL/kg/min or SVC flow > 99 mL/kg/min (sensitivities 70 and 43%, specificities 48 and 73%, respectively).

CONCLUSION

 Preterm neonates with higher markers of cardiac output in the first 12 hours of birth later required PDA treatment. These data are the first to use standard cardiac output measures in the first 12 hours of life to predict the need for future PDA treatment. Further prospective studies will need to be performed to corroborate these associations between echocardiographic markers and clinical outcomes/morbidities.

KEY POINTS

· Early diagnosis of hsPDA may prevent severe morbidity and death.. · There are echocardiographic markers beyond duct size and flow direction that may aid early diagnosis.. · Cardiac output markers within the first 12 hours of life may predict need for treatment of hsPDA..

Guidelines and Recommendations for Targeted Neonatal Echocardiography and Cardiac Point-of-Care Ultrasound in the Neonatal Intensive Care Unit: An Update from the American Society of Echocardiography

Targeted neonatal echocardiography (TNE) involves the use of comprehensive echocardiography to appraise cardiovascular physiology and neonatal hemodynamics to enhance diagnostic and therapeutic precision in the neonatal intensive care unit. Since the last publication of guidelines for TNE in 2011, the field has matured through the development of formalized neonatal hemodynamics fellowships, clinical programs, and the expansion of scientific knowledge to further enhance clinical care. The most common indications for TNE include adjudication of hemodynamic significance of a patent ductus arteriosus, evaluation of acute and chronic pulmonary hypertension, evaluation of right and left ventricular systolic and/or diastolic function, and screening for pericardial effusions and/or malpositioned central catheters. Neonatal cardiac point-of-care ultrasound (cPOCUS) is a limited cardiovascular evaluation which may include line tip evaluation, identification of pericardial effusion and differentiation of hypovolemia from severe impairment in myocardial contractility in the hemodynamically unstable neonate. This document is the product of an American Society of Echocardiography task force composed of representatives from neonatology-hemodynamics, pediatric cardiology, pediatric cardiac sonography, and neonatology-cPOCUS. This document provides (1) guidance on the purpose and rationale for both TNE and cPOCUS, (2) an overview of the components of a standard TNE and cPOCUS evaluation, (3) disease and/or clinical scenario-based indications for TNE, (4) training and competency-based evaluative requirements for both TNE and cPOCUS, and (5) components of quality assurance. The writing group would like to acknowledge the contributions of Dr. Regan Giesinger who sadly passed during the final revisions phase of these guidelines. Her contributions to the field of neonatal hemodynamics were immense.

Trial of Selective Early Treatment of Patent Ductus Arteriosus with Ibuprofen

BACKGROUND

The cyclooxygenase inhibitor ibuprofen may be used to treat patent ductus arteriosus (PDA) in preterm infants. Whether selective early treatment of large PDAs with ibuprofen would improve short-term outcomes is not known.

METHODS

We conducted a multicenter, randomized, double-blind, placebo-controlled trial evaluating early treatment (≤72 hours after birth) with ibuprofen for a large PDA (diameter of ≥1.5 mm with pulsatile flow) in extremely preterm infants (born between 23 weeks 0 days' and 28 weeks 6 days' gestation). The primary outcome was a composite of death or moderate or severe bronchopulmonary dysplasia evaluated at 36 weeks of postmenstrual age.

RESULTS

A total of 326 infants were assigned to receive ibuprofen and 327 to receive placebo; 324 and 322, respectively, had data available for outcome analyses. A primary-outcome event occurred in 220 of 318 infants (69.2%) in the ibuprofen group and 202 of 318 infants (63.5%) in the placebo group (adjusted risk ratio, 1.09; 95% confidence interval [CI], 0.98 to 1.20; P = 0.10). A total of 44 of 323 infants (13.6%) in the ibuprofen group and 33 of 321 infants (10.3%) in the placebo group died (adjusted risk ratio, 1.32; 95% CI, 0.92 to 1.90). Among the infants who survived to 36 weeks of postmenstrual age, moderate or severe bronchopulmonary dysplasia occurred in 176 of 274 (64.2%) in the ibuprofen group and 169 of 285 (59.3%) in the placebo group (adjusted risk ratio, 1.09; 95% CI, 0.96 to 1.23). Two unforeseeable serious adverse events occurred that were possibly related to ibuprofen.

CONCLUSIONS

The risk of death or moderate or severe bronchopulmonary dysplasia at 36 weeks of postmenstrual age was not significantly lower among infants who received early treatment with ibuprofen than among those who received placebo. (Funded by the National Institute for Health Research Health Technology Assessment Programme; Baby-OSCAR ISRCTN Registry number, ISRCTN84264977.).

Left ventricular diastolic function and respiratory outcomes in preterm infants: a retrospective study

BACKGROUND

The role of left ventricular (LV) diastolic pressure in the pathophysiology of bronchopulmonary dysplasia (BPD) is unclear. We evaluated the trajectory of echocardiographic parameters of LV diastolic function and the association with respiratory outcomes in preterm infants.

METHODS

We retrospectively analysed measurements of LV diastolic function (E, e', A, Ee' and E/A ratios) in infants below 32 weeks' gestation (GA). We compared infants with and without BPD by two-way RM ANOVA. We considered Ee' ratio as a proxy of LV filling pressure and identified a cut-off value using ROC analysis. We divided infants using such threshold and compared respiratory outcomes between groups by Mann-Whitney or Chi-square tests.

RESULTS

We included 72 infants. Ee' ratio at 28 days was significantly associated with the duration of respiratory support (beta (std. error) = 5.32 (1.82), p = 0.005) and BPD (beta = 0.27 (0.10), p = 0.008). Infants with Ee' ratio > 12 at 28 days had longer respiratory support, oxygen requirement, and higher BPD rates than infants with Ee' ratio ≤ 12.

CONCLUSION

LV diastolic function associated with elevated LV filling pressure may contribute to the pathophysiology of BPD. Serial echocardiographic measurements could identify infants at risk of worse respiratory outcomes.

IMPACT

In very preterm infants, we assessed the trajectory of left ventricular diastolic function by serial echocardiographic evaluations and evaluated its association with respiratory outcomes. On average, infants who developed bronchopulmonary dysplasia had higher Ee' at 28 postnatal days and 36 weeks postmentrual age than infants who did not develop the disease. Infants with elevated Ee' at 28 postnatal days, suggestive of elevated left atrial pressure, required longer respiratory support.

Clinical and echocardiographic characteristics associated with evolution of patent ductus arteriosus in preterm neonates: A prospective cohort study

BACKGROUND

In preterm infants, persistence of ductus arteriosus is an important medical condition. Functional echocardiography for patent ductus arteriosus (PDA) may guide clinical decision-making regarding treatment requirement strategies. Objectives of the study were to assess the trends of clinical and functional echocardiographic parameters with evolution of ductus arteriosus in babies≤1250 gm of birth weight and to evaluate whether there is any association of these parameters with persistence of ductus.

METHODS

In this prospective observational study, recruited babies were assessed serially for clinical events and functional echocardiography. Babies were classified into three groups: without PDA, with PDA but PDA spontaneously closed (within 7 days) and persistent PDA.

RESULT

We included 143 infants (Birth weight 1017±179 g, gestational age 30.8±2.7 weeks). Out of 60 babies with PDA, PDA failed to close spontaneously in first week in 32 (53.4 %) infants. PDA Doppler flow pattern on day 3 was found to be one of the most significant markers for future ductus. The highest frequency of growing pattern (37.5%) and pulsatile pattern (59.4%) was seen in persistence ductus group. PDA diameter and LA/Ao ratio were found strongly correlated with all other variables except E/A ratio.

CONCLUSION

We noticed persistence of ductus in preterm infants had significant clinical and echocardiographic association. PDA doppler flow pattern on day 3 was found to be a significant marker for future behaviour of ductus. Significant correlation was found among individual functional echocardiographic parameters in babies with PDA. This would guide judicious treatment of PDA in preterm neonates.

Patent ductus arteriosus, tracheal ventilation, and the risk of bronchopulmonary dysplasia

BACKGROUND

An increased risk for bronchopulmonary dysplasia (BPD) exists when moderate-to-large patent ductus arteriosus shunts (hsPDA) persist beyond 14 days.

GOAL

To examine the interaction between prolonged exposures to tracheal ventilation (≥10 days) and hsPDA on the incidence of BPD in infants <28 weeks gestation.

STUDY DESIGN

Predefined definitions of prolonged ventilation (≥10 days), hsPDA (≥14 days), and BPD (room air challenge test at 36 weeks) were used to analyze deidentified data from the multicenter TRIOCAPI RCT in a secondary analysis of the trial.

RESULTS

Among 307 infants who survived >14 days, 41 died before 36 weeks. Among survivors, 93/266 had BPD. The association between BPD and hsPDA depended on the length of intubation. In multivariable analyses, prolonged hsPDA shunts were associated with increased BPD (odds ratio (OR) (95% confidence interval (CI)) = 3.00 (1.58-5.71)) when infants required intubation for ≥10 days. In contrast, there was no significant association between hsPDA exposure and BPD when infants were intubated <10 days (OR (95% CI) = 1.49 (0.98-2.26)). A similar relationship between prolonged hsPDA and length of intubation was found for BPD/death (n = 307): infants intubated ≥10 days: OR (95% CI) = 2.41 (1.47-3.95)); infants intubated <10 days: OR (95% CI) = 1.37 (0.86-2.19)).

CONCLUSIONS

Moderate-to-large PDAs were associated with increased risks of BPD and BPD/death-but only when infants required intubation ≥10 days.

IMPACT

Infants with a moderate-to-large hsPDA that persist beyond 14 days are only at risk for developing BPD if they also receive prolonged tracheal ventilation for ≥10 days. Infants who receive less ventilatory support (intubation for <10 days) have the same incidence of BPD whether the ductus closes shortly after birth or whether it persists as a moderate-to-large shunt for several weeks. Early PDA closure may be unnecessary in infants who require short durations of intubation since the PDA does not seem to alter the incidence of BPD in infants who require intubation for <10 days.

Massive Gastric Hemorrhage after Indomethacin Therapy: A Rare Presentation and Critical Management in an Extremely Preterm Infant

Indomethacin has been widely used in preterm infants with hemodynamically significant patent ductus arteriosus (PDA). Gastrointestinal complications of indomethacin have been reported in 5% of treated neonates. However, massive gastric mucosa hemorrhage is a rarely reported complication. To the best of our knowledge, the infant in this report is the smallest reported in the literature to have undergone successful surgery for such a complication. A male preterm infant weighing 566 g was born at 25^2/7 weeks of gestational age without a complicated maternal history. Soon after birth, he received nasal noninvasive respiratory support and minimal feeding. PDA was observed since the first day of life (DOL), treatments were initiated on the second DOL for the hemodynamical significance, and PDA was closed after two courses of indomethacin therapy (0.2 mg/kg). At midnight on the seventh DOL, generalized pallor, bloody gastric drainage, and a distended stomach were observed. Massive gastric bleeding was suspected. He suffered from intermittent hypotension, which was corrected with blood products and fluid resuscitation under monitoring with a radial arterial line. Gastric lavage with cooling saline was performed twice but in vain. Prior to surgical consultation, intravascular volume transfusion was given twice. An exploratory laparotomy was arranged after obtaining the parents' consent. Blood oozing from the gastric mucosa was observed through gastrostomy and was successfully stopped via epinephrine-soaked gauze compression. After the operation, his clinical course remained uneventful, and he was discharged without neurological anomaly at two-year follow-up. Physicians need to be cautious of indomethacin's effect on platelet dysfunction in preterm infants with multiple predisposing factors. The tendency for mucosal bleeding should be continuously monitored after indomethacin therapy.

Effects of Antenatal Magnesium Sulfate on the Gut Function of Preterm (<32 weeks) Very Low Birth Weight Neonates: Experience from a Tertiary Institute in South India

OBJECTIVE

Antenatal magnesium sulfate (MgSO4) is found to have various adverse effects in newborn, but the effect on preterm gut is still unclear. This study aimed to evaluate the effects of antenatal MgSO4 on preterm gut function by assessing the clinical outcomes and mesenteric blood flow.

METHODS

This was a prospective cohort study on all preterm very low birth weight (VLBW) neonates born at a tertiary care center in South India from November 2016 to August 2017. Neonates with antenatal magnesium (Mg) exposure were compared with those with no exposure for various neonatal outcome variables like time to reach full feeds, feed intolerance, necrotizing enterocolitis (NEC) and other preterm complications, serial serum Mg levels and superior mesenteric artery (SMA) Doppler velocity measurements at two time points (24-48 h and 4-5 days after birth).

RESULTS

Out of 84 neonates, 56 neonates were exposed to antenatal Mg with a median cumulative maternal dose of 28 g and the rest 28 neonates had no exposure. The mean time to reach full feeds was the same in both groups (10.5 days). Feed intolerance episodes were similar in the first week of life between the exposed and unexposed groups (48.2% vs. 46.4%; p = 0.88). Univariate analysis revealed no difference between groups concerning rates of NEC (p = 0.17) or mortality (p = 0.39). There was no significant difference in SMA Doppler parameters and hypermagnesemia between the two groups.

CONCLUSION

Our study found no significant impact on postnatal feed tolerance and mesenteric blood flow among preterm VLBW neonates with antenatal MgSO4 exposure.

A randomized trial of intravenous acetaminophen versus indomethacin for treatment of hemodynamically significant PDAs in VLBW infants

Objective was to compare the rate of successful treatment of hsPDA based on echocardiogram criteria after use of IV acetaminophen or IV indomethacin in very low-birthweight infants. The study was a multi-center, randomized controlled trial. Infants born prior to 32 weeks with birthweight ≤ 1500 g were included if PDA treatment was indicated within the 21 days after birth. hsPDA was defined by strict echocardiogram criteria. Eligible infants were randomized to treatment with either IV acetaminophen or IV indomethacin. Of 86 eligible infants, 17 infants were randomized to acetaminophen and 20 to indomethacin. One (5.9%) hsPDA in the acetaminophen group had successful treatment compared to 11 (55%) in the indomethacin group (p = 0.002). Eight (47%) in the acetaminophen group and 3 (15%) in the indomethacin group received transcatheter PDA closure (p = 0.07). IV indomethacin was more effective than IV acetaminophen for treatment of hsPDAs. More infants in the acetaminophen group received transcatheter closure.

Early PARacetamol (EPAR) Trial: A Randomized Controlled Trial of Early Paracetamol to Promote Closure of the Ductus Arteriosus in Preterm Infants

INTRODUCTION

This study aimed to investigate whether early treatment with paracetamol reduces the number of infants requiring intervention for patent ductus arteriosus (PDA) and assess the safety profile of paracetamol during the early postnatal period.

METHODS

This was a double-blind, parallel, randomized, placebo-controlled trial. Preterm infants born at <29-week gestation with a ductus arteriosus >0.9 mm at 6 h of life were randomized to either (1) intravenous paracetamol (15 mg/kg initially and then 7.5 mg/kg every 6 h) or (2) intravenous dextrose for 5 days. The primary outcome was the need for any intervention for PDA up to 5 days. Secondary outcomes included ductal closure at 5 days, ductal size at 48 h, ductal reopening, mortality, and significant morbidities.

RESULTS

Of 58 infants randomized, 29 were allocated to the intervention and 29 to the control group. The trial was stopped for benefit at 50% recruitment after reaching the prespecified stopping criteria. Less infants in the intervention group required intervention for PDA up to 5 days (6 [21%] vs. 17 [59%] infants [p = 0.003]; relative risk reduction 0.35 [95% CI 0.16-0.77; NNT 2.6]). The intervention group had a higher rate of ductal closure (20 [69%] vs. 8 [28%] infants [p = 0.002]) and smaller ductal size (1.0 mm [±0.8] vs. 1.4 mm [±0.9]; p = 0.04). Three deaths occurred (2 in the intervention group), which were not attributed to the intervention. No other adverse events were reported.

DISCUSSION/CONCLUSION

Early paracetamol treatment reduced the number of infants requiring intervention for PDA. Short-term safety data were reassuring, acknowledging the small number of infants involved in the study.

Oxidative and Proteolytic Inactivation of Alpha-1 Antitrypsin in Bronchopulmonary Dysplasia Pathogenesis: A Top-Down Proteomic Bronchoalveolar Lavage Fluid Analysis

The study investigates the role of the oxidative and proteolytic inactivation of alpha-1 antitrypsin (AAT) in the pathogenesis of bronchopulmonary dysplasia (BPD) in premature infants. Bronchoalveolar lavage fluid (BALF) samples were collected on the 3rd day of life from mechanically ventilated neonates with gestational age ≤ 30 weeks and analyzed without previous treatment (top-down proteomics) by reverse-phase high-performance liquid chromatography-electrospray ionization mass spectrometry. AAT fragments were identified by high-resolution LTQ Orbitrap XL experiments and the relative abundances determined by considering the extracted ion current (XIC) peak area. Forty preterm neonates were studied: 20 (50%) did not develop BPD (no-BPD group), 17 (42.5%) developed mild or moderate new-BPD (mild + moderate BPD group), and 3 (7.5%) developed severe new-BPD (severe BPD group). Eighteen fragments of AAT and a fragment of AAT oxidized at a methionine residue were identified: significantly higher values of AAT fragments 25-57, 375-418, 397-418, 144-171, and 397-418 with oxidized methionine were found in the severe BPD group. The significantly higher levels of several AAT fragments and of the fragment 397-418, oxidized in BALF of preterm infants developing BPD, underlie the central role of an imbalance between proteases and protease inhibitors in exacerbating lung injury and inducing most severe forms of BPD. The study has some limitations, and between them, the small sample size implies the need for further confirmation by larger studies.

Spontaneous Closure of the Ductus Arteriosus in Preterm Infants: A Systematic Review

The optimal management strategy for patent ductus arteriosus in preterm infants remains a topic of debate. Available evidence for a treatment strategy might be biased by the delayed spontaneous closure of the ductus arteriosus in preterm infants, which appears to depend on patient characteristics. We performed a systematic review of all literature on PDA studies to collect patient characteristics and reported numbers of patients with a ductus arteriosus and spontaneous closure. Spontaneous closure rates showed a high variability but were lowest in studies that only included preterm infants with gestational ages below 28 weeks or birth weights below 1,000 g (34% on day 4; 41% on day 7) compared to studies that also included infants with higher gestational ages or higher birth weights (up to 55% on day 3 and 78% on day 7). The probability of spontaneous closure of the ductus arteriosus keeps increasing until at least 1 week after birth which favors delayed treatment of only those infants that do not show spontaneous closure. Better prediction of the spontaneous closure of the ductus arteriosus in the individual newborn is a key factor to find the optimal management strategy for PDA in preterm infants.

Antenatal corticosteroids administration on mortality and morbidity in premature twins born at 25∼34 gestational weeks: A retrospective multicenter study

OBJECTIVE

To evaluate the effects of antenatal corticosteroids (ACS) administration on mortality and major neonatal complications in early life of preterm twins.

STUDY DESIGN

This study retrospectively enrolled 1 662 twins delivered at 25∼34⁺⁶gestational weeks in China from January 2013 to December 2014. They were divided into ACS group and no-ACS group according to weather their mothers received ACS or not. Moreover, they were subgrouped as 25∼27⁺⁶ and 28∼34⁺⁶gestational week groups. Multivariable logistic regression was used to analyze the effects of ACS on the incidence of mortality and major morbidities.

RESULTS

A total of 910 neonates (54.8 %) received one or more doses of ACS, and 752 neonates (45.2 %) did not receive any ACS. No significant difference in infant mortality was observed between the ACS and no-ACS groups (P = 0.321). The ACS group had decreased incidence of respiratory distress syndrome (RDS) and mild RDS compared with the no-ACS group (both P < 0.05). There were no significant differences in the incidence of bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, patent ductus arteriosus, sepsis and severe RDS between the two groups (all P > 0.05). The subgroup analysis showed that the incidence of RDS was lower in the ACS group than in the no-ACS group (P = 0.036) at 28∼34⁺⁶weeks. However, the incidence of mild ROP was higher in the ACS group than that in the no-ACS group (P = 0.047) at 25∼27⁺⁶ weeks. Multivariable logistic regression analysis demonstrated a decreasing risk of RDS (aOR = 0.661, 95 %CI:0.506-0.863, P = 0.002) after adjusting the gestational week, birth weight, small for gestational age, delivery mode, 5 min Apgar score, and maternal perinatal complications.

CONCLUSION

In twin preterm infants, ACS administration is associated with a reduced risk of RDS. However, our data suggest that it may not have a beneficial effect on mortality and other short-term morbidities.

Therapeutic strategy of patent ductus arteriosus in extremely preterm infants

The ductus arteriosus is likely to close without treatment in most infants born at gestational age (GA) > 28 weeks (73%), and those with birth weight > 1000 g (94%). However, the rates of spontaneous ductal closure among less mature or smaller infants with respiratory distress syndrome are not known. Extremely preterm infants born at GA < 28 weeks are associated with a high risk of severe intraventricular hemorrhage (IVH) or pulmonary hemorrhage, which usually occur within 72 h after birth and affect mortality and long-term neurological development. These serious hemorrhagic complications may be closely related to hemodynamic changes caused by a hemodynamically significant patent ductus arteriosus (hs-PDA). While prophylactic indomethacin has been shown to reduce the rates of PDA, PDA ligation, severe IVH and early pulmonary hemorrhage, the available evidence does not support its prophylactic use in preterm infants. Symptomatic or late treatment is associated with lower success rate, and increased complications of a hs-PDA. The issue of "to treat or not to treat a PDA" is controversial. Considering the relationship between the effectiveness and timing of pharmacological treatment, early targeted treatment may be an alternative approach for the early identification of a hs-PDA in specific high-risk patient population, especially infants <26 weeks GA who are at the highest risk of severe IVH or pulmonary hemorrhage. Serial echocardiographic studies can be used to select patients who are candidates for early targeted medical treatment of hs-PDA. Surgical ligation of PDA, and transcatheter closure if proven to be safe, can be used as back-up therapy for patients who fail medical treatment and continue to have cardiopulmonary compromise.

Patent ductus arteriosus in preterm infants: is early transcatheter closure a paradigm shift?

The optimal management approach of the patent ductus arteriosus (PDA) in premature infants remains uncertain owing the lack of evidence for long-term benefits and the limited analyses of the complications of medical and surgical interventions to date. In recent years, devices suitable to plug the PDA of premature infants (including extremely low birthweight, <1000 g) have become available and several trials have demonstrated successful and safe transcatheter PDA closure (TCPC) in this population. Whether TCPC represents a paradigm shift in PDA management that will result in improved short- and long-term outcomes, less bronchopulmonary dysplasia, improved neurodevelopment, or better long term renal function remains to be seen. Careful rigorous study of the potential benefits of TCPC in this highly vulnerable population in the context of well-designed adequately powered trials is needed prior to widespread adoption of this approach.

Ductal size indexed to weight and body surface area correlates with morbidities in preterm infants ≤32 weeks

OBJECTIVES

To assess ductal size correlated to spontaneous closure, pharmacological or surgical treatment; to index ductal diameter to body weight and body surface area; to evaluate the morbidities.

STUDY DESIGN

Retrospective study on preterms ≤32 weeks, birth weight ≤1500 g, extremely low birth weight (ELBW) and very low birth weight (VLBW). Inclusion criteria: patent ductus arteriosus (PDA) with a diameter ≥1 millimeter (mm) at 72 h from birth; need for ibuprofen treatment on the basis of a hemodynamically significant ductus arteriosus (HsPDA).

RESULTS

One hundred infants with the diagnosis of PDA have been included. We observed a prevalence of spontaneous closure in 34% of newborns (41.3% VLBW versus 26.7% ELBW). The percentage of response to a single course of ibuprofen was of 62% (68.5% ELBW versus 54.3% VLBW). The mean of absolute ductal diameter was of 2.26 ± 0.62 mm in ELBW and 2.18 ± 0.42 mm in VLBW. The indexing of ductus size to body weight demonstrated a higher value in ELBW than VLBW (2.76 ± 0.97 mm/kg versus 1.84 ± 0.40 mm/kg).

CONCLUSIONS

Our results confirmed that HsPDA can develop in presence of a ductus >1.5 mm as absolute value or >1.4 mm/kg as indexed to body weight. In ELBW infants the ductal size indexed for body weight and body surface area could be more predictive of spontaneous closure or need for pharmacological treatment compared to the absolute value of ductal size. A strong association between HsPDA and short- or long-term morbidities was confirmed particularly in ELBW.

Prediction of ductus closure and development of adverse clinical outcome by functional echocardiography in very low birth weight newborn

OBJECTIVE

To evaluate the role of functional echocardiography for prediction of patent ductus arteriosus (PDA) closure and development of adverse outcome in very low birth weight newborn.

METHODS AND STUDY DESIGN

Functional echocardiography was done in 143 neonates with birth weight less than 1250 g on day 3. Nine echocardiographic parameters were analyzed for babies with PDA for prediction of spontaneous closure and development of one or more adverse outcomes (bronchopulmonary dysplasia, necrotizing enterocolitis≥stage 2 and intraventricular hemorrhage > grade 2) during hospital stay.

RESULT

The mean (±SD) birthweight and gestational age of the cohort were 1017 (±17) g and 30.8 (±2.7) weeks. PDA was found in 60 (41.9%) babies on day 3 among the recruited babies. Binary logistic regression model showed strong prediction ability of early (day 3) functional echocardiography markers in predicting future spontaneous closure of PDA and development of one or more adverse clinical outcome. In multivariate analysis, abnormal flow pattern (growing or pulsatile) was found to have increased risk for persistence of PDA (adjusted OR 22.9, CI 1.97-269) in comparison to PDA with closing/bidirectional pattern.

CONCLUSION

Early functional echocardiography, especially the flow pattern, is useful for prediction of PDA closure. Adverse clinical outcome prediction is possible with functional echocardiography markers when combined with gestational age and PDA closure status.

Changes in hemodynamics, cerebral oxygenation and cerebrovascular reactivity during the early transitional circulation in preterm infants

BACKGROUND

Changes in systemic and cerebral hemodynamics in preterm infants during early transitional circulation are complex and may differ between infants with or without intraventricular hemorrhage (IVH).

METHOD

In total, 43 infants born at median (range) 25 + 5 (23 + 3-31) had continuous near-infrared spectroscopy (NIRS) monitoring of tissue oxygenation index (TOI) and cerebrovascular reactivity within the first 48 h of life. Measurements of left and right cardiac outputs (LVO, RVO) and patent ductus arteriosus (PDA) were collected at 6, 12, 24, and 48 h of life.

RESULTS

LVO increased within the first 48 h in the IVH (P = 0.007) and no-IVH (P < 0.001) groups. The pattern of change in LVO and RVO was not different between these two groups. TOI was lower in the IVH (P < 0.001) group. A positive correlation between TOI and LVO (P = 0.003) and a negative correlation between the tissue oxygen reactivity index (TOx) and LVO (P = 0.04) were observed at 24 h of life in the IVH group. PDA diameter was not different between IVH groups at any time interval.

CONCLUSION

Cerebral oxygenation was lower and cerebrovascular reactivity was passive to systemic blood flow at 24 h in infants who developed an IVH.

The association between NIRS and Doppler ultrasonography in preterm infants with patent ductus arteriosus

Objective: To determine if near-infrared spectroscopy (NIRS), which is easier to obtain than Doppler ultrasonography (USG), may be used in accordance with Doppler USG to provide additional data for assessment of organ blood flow velocities in preterm infants with hemodynamically significant PDA.Study design: Thirty-one infants who were treated with ibuprofen for closure of PDA were monitored continuously with NIRS. Cerebral, mesenteric, and renal arterial blood flow velocities were measured with Doppler USG before and after the treatment.Results: While cerebral, mesenteric, and renal fractional oxygen extraction (FTOE) measurements decreased significantly (p = .042, p < .001, p < .001, respectively), NIRS measurements (p = .016, p < .001, p < .001, respectively) and mean blood flow velocities (p = .003, p = .011, p = .002, respectively) increased significantly after the treatment. There was a significant correlation between pretreatment cerebral and mesenteric FTOE and resistive index (RI) values (r = 0.45, p = .01, and r = 0.46, p = .01, respectively). However, no correlation was observed between renal FTOE values and renal RI (r = 0.33, p = .06). Posttreatment cerebral, renal, and mesenteric FTOE values correlated positively with corresponding RI (r = 0.41, p = .02; r = 0.39, p = .02; r = 0.65, p < 01; respectively). Pretreatment and posttreatment cerebral, mesenteric, and renal FTOE values and arterial mean velocities were inversely correlated (pretreatment: r = 0.69, p < .01; r = 0.72, p < .01; r = 0.77, p < .01; posttreatment: r = 0.54, p = .01; r = 0.69, p < .01; r = 0.38, p = .01; respectively).Conclusion: As Doppler and NIRS measurements correlated significantly, we concluded that NIRS might be used in monitoring organ blood flow in preterm infants with PDA, which may provide additional data for management of this condition.

Echocardiography of the patent ductus arteriosus in premature infant

Management of the patent ductus arteriosus (PDA) in the premature infant has been a point of controversy for decades as smaller and earlier gestational age infants have been surviving. Increasing experience with catheter-based device closure has generated a new wave of interest in this subject. In this era, echocardiography plays a central role for collaboration within a multispecialty team. Reliability of echocardiography is improved by applying an institutionally derived standard approach to imaging, data collection, and reporting. The key aspects of both the physiology and anatomy of the PDA to distinguish infants that may benefit from intervention are described.

Blood pressure intervention levels in preterm infants: pilot randomised trial

OBJECTIVE

To examine the feasibility of a trial allocating different blood pressure (BP) intervention levels for treatment in extremely preterm infants.

DESIGN

Three-arm open randomised controlled trial performed between February 2013 and April 2015.

SETTING

Single tertiary level neonatal intensive care unit.

PATIENTS

Infants born <29 weeks' gestation were eligible to participate, if parents consented and they did not have a major congenital malformation.

INTERVENTIONS

Infants were randomised to different levels of mean arterial BP at which they received cardiovascular support: active (<30 mm Hg), moderate (<gestational age mm Hg) or permissive (signs of poor perfusion or <19 mm Hg). Once this threshold was breached, all were managed using the same treatment guideline. BP profiles were downloaded continuously; cardiac output and carotid blood flow were measured at 1 day and 3 days, and amplitude integrated EEG was recorded during the first week. Cranial ultrasound scans were reviewed blind to study allocation.

MAIN OUTCOME MEASURE

Inotrope usage and achieved BP.

RESULTS

Of 134 cases screened, 60 were enrolled, with mean gestation 25.8 weeks (SD 1.5) and birth weight 817 g (SD 190). Invasively measured BP on the first day and inotrope usage were highest in the active and lowest in the permissive arms. There were no differences in haemodynamic or EEG variables or in clinical complications. Predefined cranial ultrasound findings did not differ significantly; no infants in the active arm had parenchymal brain lesions.

CONCLUSION

The BP threshold used to trigger treatment affects the achieved BP and inotrope usage, and it was possible to explore these effects using this study design.

TRIAL REGISTRATION NUMBER

ISRCTN83507686.

A pilot randomised blinded placebo-controlled trial of paracetamol for later treatment of a patent ductus arteriosus

OBJECTIVE

To explore the efficacy and risks of oral paracetamol in later (>2 weeks old) treatment of patent ductus arteriosus (PDA).

STUDY DESIGN

A multicentre double-blind placebo-controlled randomised pilot trial in three neonatal intensive care units in Australia. Infants born <33 weeks with haemodynamically significant PDA were treated with a 5-day course of oral paracetamol or placebo. Cardiac ultrasounds were used to document haemodynamic parameters. The primary outcome analysed was ductal closure by 48 h after treatment completion. Secondary outcomes included reduction in ductal diameter >25% and safety.

RESULTS

Fifty-five infants were enrolled, of whom 27 received paracetamol and 28 placebo. Eighty percent had received previous non-steroidal anti-inflammatory drug. Mean postnatal age was 25 days. Four of the 27 ducts treated with paracetamol closed vs. 0/28 treated with placebo (p = 0.05). An additional 13/27 given  paracetamol vs. 7/28 given placebo showed significant constriction (p = 0.008). No adverse effects were observed .

CONCLUSIONS

There was some evidence of increased closure with oral paracetamol at postnatal age >2 weeks; however, the overall efficacy was not high.

Turkish Neonatal Society guideline on the management of patent ductus arteriosus in preterm infants

Ductus arteriosus is a physiologic phenomenon in utero and it closes spontaneously in term babies. The closure is problematic in preterm infants due to the intrinsic properties of the preterm ductus arteriosus tissue. Although patent ductus arteriosus has been reported to be associated with many adverse outcomes in this population, treatment has not led to a decrease in outcomes such as bronchopulmonary dysplasia. Treatment modalities also have their own risks and restrictions. The aim of the "Turkish Neonatal Society guidelines for the management of patent ductus arteriosus in preterm babies" is to standardize the diagnosis and treatment of patent ductus arteriosus in preterm infants by combining the current scientific data and the resources of our country.

What is a hemodynamically significant PDA in preterm infants?

OBJECTIVE

There is no consensus on the definition of a hemodynamically significant patent ductus arteriosus (hsPDA). In this review article, our objective is to discuss the main variables that one should consider when determining the hemodynamic significance of a PDA.

RESULTS

We describe the various approaches that have been utilized over time to define an hsPDA and discuss the strengths and weaknesses of each echocardiographic index. Finally, we propose a comprehensive and individualized approach in determining the hemodynamic significance of the PDA.

CONCLUSION

There are several PDA-related clinical, echocardiographic, and other objective variables to take into consideration when defining an hsPDA. However, vulnerability based on gestational or chronological age is an important contributor as well.

A literature review of systemic to pulmonary collaterals in preterm infants to emphasise their existence and clinical importance

AIM

Cardiorespiratory physiology plays an important role in neonatal care with increasing utility of point-of-care ultrasound. This review is to bring to light the importance of systemic to pulmonary collaterals (SPCs) in the preterm population without congenital heart disease (CHD) and provide a useful diagnostic tool to the neonatologist performing a cardiac ultrasound.

METHODS

Medline, PubMed, EMBASE and the Internet were searched up to November 2017 for articles in English which included SPCs in preterm infants without CHD. This comprised title, abstract and full-text screening of relevant data.

RESULTS

A total of 10 studies which included case reports, retrospective observational studies and one small prospective cohort study were identified and analysed in detail. The studies had varying focus such as variable incidence, clinical presentation, association with chronic lung disease, pathophysiology and clinical importance of SPCs. SPCs were overall thought to be prevalent, underdiagnosed and of clinical significance in preterm infants.

CONCLUSION

Systemic to pulmonary collaterals are a potential left-to-right shunt in preterm infants and may contribute to worsening chronic lung disease (CLD) or heart failure. They should be carefully looked for when performing bedside cardiac ultrasound as the findings can mimic those seen in patent ductus arteriosus (PDA).

Role of neonatologist-performed echocardiography in the assessment and management of patent ductus arteriosus physiology in the newborn

Neonatologist-performed echocardiography (NPE) is an indispensable tool in the haemodynamic management of critically ill newborn infants. NPE is used to facilitate timely diagnosis of a patent ductus arteriosus (PDA) in preterm infants and to assess its haemodynamic significance. Before treatment is considered, it is obligatory to confirm structural cardiac normality. Importantly, NPE offers the ability to guide therapeutic interventions, allowing an individualised haemodynamic management approach to the PDA. After discussing PDA pathophysiology, an overview is provided on the role of NPE in the assessment and management of PDA in preterm infants.

Fetal Doppler velocimetry and bronchopulmonary dysplasia risk among growth-restricted preterm infants: an observational study

OBJECTIVE

To investigate whether fetal growth restriction (FGR) diagnosis, based on pathological prenatal fetal Doppler velocimetry, is associated with bronchopulmonary dysplasia (BPD) independently of being small for gestational age (SGA) per se at birth among very preterm infants.

DESIGN

Prospective, observational study. FGR was defined as failing fetal growth in utero and fetal Doppler velocimetry abnormalities.

SETTING

Policlinico Universitario Agostino Gemelli, Roma, Italy.

PATIENTS

Preterm newborns with gestational age ≤30 weeks and birth weight (BW) ≤1250 g.

MAIN OUTCOME MEASURES

Bronchopulmonary dysplasia.

RESULTS

In the study period, 178 newborns were eligible for the study. Thirty-nine infants (22%) were considered fetal growth-restricted infants. Among the 154 survived babies at 36 weeks postmenstrual age, 12 out of 36 (33%) of the FGR group developed BPD versus 8 out of 118 (7%) of the NO-FGR group (p<0.001). BPD rate was sixfold higher among the SGA-FGR infants compared with the SGA-NO-FGR infants. In a multivariable model, FGR was significantly associated with BPD risk (OR 5.1, CI 1.4 to 18.8, p=0.01), independently from BW z-score that still remains a strong risk factor (OR 0.5, CI 0.3 to 0.9, p=0.01).

CONCLUSION

Among SGA preterm infants, BPD risk dramatically increases when placenta dysfunction is the surrounding cause of low BW. Antenatal fetal Doppler surveillance could be a useful tool for studying placenta wellness and predicting BPD risk among preterm babies. Further research is needed to better understand how FGR affects lung development.

Surgical Ligation for Patent Ductus Arteriosus in Extremely Premature Infants: Strategy to Reduce their Risk of Neurodevelopmental Impairment

Surgical ligation for patent ductus arteriosus (PDA) in extremely low birth weight infants (ELBWIs) has been shown a possible association with neurodevelopmental impairment (NDI) because of its invasiveness. However, we have undergone surgical ligation for ELBWIs immediately after cyclooxygenase inhibitor failed to close a hemodynamically significant PDA (hsPDA) to maintain proper systemic circulation. We aimed to determine the effect of surgical ligation for hsPDA on NDI in ELBWIs. In enrolled 71 ELBWIs, the clinical parameters, including the developmental quotient (DQ), were collected and compared among three groups that were divided by closure mode: spontaneous closure (n = 11), cyclooxygenase inhibitor therapy (n = 37) and surgical ligation (n = 23). No significant differences in DQ at the age of 36 months among the three groups were found: Median (interquartile range): 92.0 (31.0), 89.0 (22.0) and 92.0 (24.5), respectively. In a comparison between groups of DQ < 70 (n = 15) and DQ ≥ 70 (n = 56), a significant difference was found in the parameters related to prematurity (p < 0.05 for each): gestational age [23.9 (1.70) vs. 25.4 (2.50) weeks], birth weight [595 (183) vs. 714 (192) g], Apgar score < 5 (1 min) (67% vs. 36%), and laser photocoagulation for retinopathy of prematurity (73% vs. 43%), but there was no significant association with hsPDA. Therefore, we propose that surgical ligation for hsPDA in ELBWIs should be immediately carried out for preventing future neurodevelopmental deterioration if the cyclooxygenase inhibitor failed to close hsPDA.

Circulatory Management Focusing on Preventing Intraventricular Hemorrhage and Pulmonary Hemorrhage in Preterm Infants

The goal of modern neonatal care of extremely preterm infants is to reduce mortality and long-term neurological impairments. Preterm infants frequently experience cerebral intraventricular or pulmonary hemorrhage, which usually occurs within 72 hours after birth and can lead to long-term neurological sequelae and mortality. These serious hemorrhagic complications are closely related to perinatal hemodynamic changes, including an increase in the afterload on the left ventricle of the heart after the infant is separated from the placenta, and an increased preload from a left-to-right shunt caused by a hemodynamically significant patent ductus arteriosus (PDA). The left ventricle of a preterm myocardium has limited ability to respond to such an increase in afterload and preload, and this can result in cardiac dysfunction and hemodynamic deterioration. We suggest that delayed umbilical cord clamping or umbilical cord milking to maintain optimal blood pressure and systemic blood flow (SBF), careful assessment to keep the afterload at an acceptable level, and a strategy of early targeted treatment of significant PDA to improve perfusion during this critical time period may reduce or prevent these serious complications in preterm infants.

Cerebral oxygenation and echocardiographic parameters in preterm neonates with a patent ductus arteriosus: an observational study

BACKGROUND

A haemodynamically significant patent ductus arteriosus (hsPDA) is clinically suspected and confirmed by echocardiographic examination. A hsPDA decreases cerebral blood flow and oxygen saturation by the ductal steal phenomenon.

AIM

To determine the relationship between echocardiographic parameters, cerebral oxygenation and a hsPDA in preterm infants.

METHODS

380 preterm infants (<32 weeks gestational age) born between 2008 and 2010 were included. Blinded echocardiographic examination was performed on the second, fourth and sixth day after birth. Examinations were deblinded when hsPDA was clinically suspected. Regional cerebral oxygen saturation (rScO₂) was continuously monitored by near-infrared spectroscopy during 72 h after birth, and afterwards for at least 1 h before echocardiography. Echocardiographic parameters included ductal diameter, end-diastolic flow in the left pulmonary artery, left atrium/aorta ratio and ductal flow pattern.

RESULTS

rScO₂ was significantly related only to ductal diameter over time. Mixed modelling analysed the course of rScO₂ over time, where infants were divided into four groups: a closed duct, an open haemodynamically insignificant duct (non-sPDA), a hsPDA, which was successfully closed during study period (SC hsPDA) or a hsPDA, which was unsuccessfully closed during study period (UC hsPDA). SC hsPDA infants showed the highest rScO₂ on day 6, while UC hsPDA infants had the lowest rScO₂ values.

CONCLUSIONS

Ductal diameter is the only echocardiographic parameter significantly related to cerebral oxygenation over time. Cerebral oxygenation takes a different course over time depending on the status of the duct. Low cerebral oxygenation may be suggestive of a hsPDA.

Velocity time integral for right upper pulmonary vein in VLBW infants with patent ductus arteriosus

OBJECTIVE:

Early diagnosis of significant patent ductus arteriosus reduces the risk of clinical worsening in very low birth weight infants. Echocardiographic patent ductus arteriosus shunt flow pattern can be used to predict significant patent ductus arteriosus. Pulmonary venous flow, expressed as vein velocity time integral, is correlated to ductus arteriosus closure. The aim of this study is to investigate the relationship between significant reductions in vein velocity time integral and non-significant patent ductus arteriosus in the first week of life.

METHODS:

A multicenter, prospective, observational study was conducted to evaluate very low birth weight infants (<1500 g) on respiratory support. Echocardiography was used to evaluate vein velocity time integral on days 1 and 4 of life. The relationship between vein velocity time integral and other parameters was studied.

RESULTS:

In total, 98 very low birth weight infants on respiratory support were studied. On day 1 of life, vein velocity time integral was similar in patients with open or closed ductus. The mean vein velocity time integral significantly reduced in the first four days of life. On the fourth day of life, there was less of a reduction in patients with patent ductus compared to those with closed patent ductus arteriosus and the difference was significant.

CONCLUSIONS:

A significant reduction in vein velocity time integral in the first days of life is associated with ductus closure. This parameter correlates well with other echocardiographic parameters and may aid in the diagnosis and management of patent ductus arteriosus.

[Factors influencing the prognosis of patent ductus arteriosus in very low birth weight infants]

OBJECTIVE

To investigate the factors influencing the prognosis of patent ductus arteriosus (PDA) in very low birth weight (VLBW) infants.

METHODS

A total of 194 VLBW infants who were admitted from January 2012 to December 2014 were enrolled as study subjects. According to cardiac ultrasound findings and treatment outcome, these infants were divided into non-PDA group, spontaneous closure group, pharmaceutical closure group, and surgical closure group. Their clinical and echocardiographic characteristics were analyzed.

RESULTS

The spontaneous closure rate of PDA was 58.7%. The spontaneous closure group showed significantly higher gestational age, birth weight, and proportion of small-for-gestational-age infants than the pharmaceutical and surgical closure groups (P<0.05). The pharmaceutical and surgical closure groups had a significantly higher incidence rate of neonatal respiratory distress syndrome and a significantly higher proportion of infants who were given pulmonary surfactant (PS) than the spontaneous closure group (P<0.05). During different periods of time, the spontaneous closure group had a significantly smaller ductus arteriosus diameter than the pharmaceutical and surgical closure groups (P<0.05). The multivariate logistic regression analysis showed that gestational age, application of PS, and ductus arteriosus diameter at 48 hours were significantly associated with the prognosis of PDA. The major transductal flow pattern in the spontaneous closure group was closing pattern, while in the pharmaceutical and surgical closure groups, the main flow patterns were pulmonary hypertension and growing patterns within 48 hours and growing pattern on days 4 and 7.

CONCLUSIONS

The VLBW infants have a high spontaneous closure rate of PDA. A decreased closure rate of PDA is associated with the lower gestational age and the application of PS. PDA with a large ductus arteriosus diameter and a growing or pulsatile flow pattern cannot easily achieve spontaneous closure.

[Factors influencing the prognosis of patent ductus arteriosus in very low birth weight infants]

OBJECTIVE

To investigate the factors influencing the prognosis of patent ductus arteriosus (PDA) in very low birth weight (VLBW) infants.

METHODS

A total of 194 VLBW infants who were admitted from January 2012 to December 2014 were enrolled as study subjects. According to cardiac ultrasound findings and treatment outcome, these infants were divided into non-PDA group, spontaneous closure group, pharmaceutical closure group, and surgical closure group. Their clinical and echocardiographic characteristics were analyzed.

RESULTS

The spontaneous closure rate of PDA was 58.7%. The spontaneous closure group showed significantly higher gestational age, birth weight, and proportion of small-for-gestational-age infants than the pharmaceutical and surgical closure groups (P<0.05). The pharmaceutical and surgical closure groups had a significantly higher incidence rate of neonatal respiratory distress syndrome and a significantly higher proportion of infants who were given pulmonary surfactant (PS) than the spontaneous closure group (P<0.05). During different periods of time, the spontaneous closure group had a significantly smaller ductus arteriosus diameter than the pharmaceutical and surgical closure groups (P<0.05). The multivariate logistic regression analysis showed that gestational age, application of PS, and ductus arteriosus diameter at 48 hours were significantly associated with the prognosis of PDA. The major transductal flow pattern in the spontaneous closure group was closing pattern, while in the pharmaceutical and surgical closure groups, the main flow patterns were pulmonary hypertension and growing patterns within 48 hours and growing pattern on days 4 and 7.

CONCLUSIONS

The VLBW infants have a high spontaneous closure rate of PDA. A decreased closure rate of PDA is associated with the lower gestational age and the application of PS. PDA with a large ductus arteriosus diameter and a growing or pulsatile flow pattern cannot easily achieve spontaneous closure.

Hemodynamic Effects of Nasal Intermittent Positive Pressure Ventilation in Preterm Infants

Nasal intermittent positive pressure ventilation (NIPPV) and nasal continuous positive airway pressure (NCPAP) have proven to be effective modes of noninvasive respiratory support in preterm infants. Although they are increasingly used in neonatal intensive care, their hemodynamic consequences have not been fully evaluated. The aim of this study was to investigate the hemodynamic changes between NIPPV and NCPAP in preterm infants.This prospective observational study enrolled clinically stable preterm infants requiring respiratory support received NCPAP and nonsynchronized NIPPV at 40/minute for 30 minutes each, in random order. Cardiac function and cerebral hemodynamics were assessed by ultrasonography after each study period. The patients continued the study ventilation during measurements.Twenty infants with a mean gestational age of 27 weeks (range, 25-32 weeks) and birth weight of 974 g were examined at a median postnatal age of 20 days (range, 9-28 days). There were no significant differences between the NCPAP and NIPPV groups in right (302 vs 292 mL/kg/min, respectively) and left ventricular output (310 vs 319 mL/kg/min, respectively), superior vena cava flow (103 vs 111 mL/kg/min, respectively), or anterior cerebral artery flow velocity.NIPPV did not have a significant effect on the hemodynamics of stable preterm infants. Future studies assessing the effect of NIPPV on circulation should focus on less stable and very preterm infants.

Association of Antegrade Pulmonary Artery Diastolic Velocity with Spontaneous Closure of the Patent Ductus Arteriosus in Extremely Low-Birth-Weight Infants

OBJECTIVE

This study aims to determine echocardiographic parameters associated with spontaneous patent ductus arteriosus (PDA) closure in extremely low-birth-weight (ELBW) infants.

STUDY DESIGN

Retrospective demographic review and analysis of echocardiograms from 189 ELBW infants with suspected and confirmed hemodynamically significant PDA identified on an initial echocardiogram was performed. Comparison of echocardiographic parameters was made between infants with spontaneous closure versus those who received treatment.

RESULTS

The mean birth weight (787 ± 142 vs. 724 ± 141 g, p = 0.04) and gestational age (27.4 ± 2.8 vs. 26.2 ± 1.6 weeks, p = 0.03) were higher in the spontaneous closure versus the treatment group. Antegrade pulmonary artery (PA) diastolic velocity was lower in infants with spontaneous PDA closure versus those who received treatment (0.15 ± 0.06 vs. 0.22 ± 0.12 m/s, p = 0.009).

CONCLUSION

Heavier and more mature ELBW infants with a lower antegrade PA diastolic velocity were likely to have spontaneous closure of the PDA.

Peak systolic to end diastolic flow velocity ratio is associated with ductal patency in infants below 32 weeks of gestation

BACKGROUND

Early diagnosis and effective treatment of the patent ductus arteriosus (PDA) in infants less than 32 weeks gestation remains contentious.

OBJECTIVE

To determine which clinical and echocardiographic parameters are associated with PDA patency in preterm infants less than 32 weeks gestation.

DESIGN/METHODS

This was a prospective cohort study. An echocardiography (echo) was performed within 12-48 h of birth and a follow-up echo at 1 month of life. Parental consent was obtained.

RESULTS

55 babies were enrolled. Median (range) gestation was 28 (24-31) weeks and birth weight 1090 g (470-1800 g). ECHO 1 demonstrated that 50 babies had a PDA present within 48 h of birth, of which 19 were large (≥2 mm) (36%) and 31 were small (59%) on colour Doppler assessment of duct diameter. Three babies died before 1 month. At 1 month 30 babies still had a PDA (58%), 10 of which were large (19%) and 19 were small (36%). Parameters significantly associated with large PDAs versus no PDA at 1 month were gestational age (26 weeks vs 30 weeks, p=0.002), birth weight (860 g vs 1290 g, p=0.007) and ventilator support at 48 h (80% vs 17%, p=0.001). Echo parameters revealed that ductal size on colour Doppler (2.5 mm vs 1.5 mm, p=0.003), end diastolic flow velocity (57 m/s vs 147 m/s, p<0.001) and peak systolic to end diastolic flow velocity ratio (2.29 vs 1.23, p=0.001) at 48 h were associated with large PDAs at 1 month.

CONCLUSIONS

For infants less than 32 weeks gestation a peak systolic to end diastolic flow velocity ratio>2 within 48 h of birth is associated with a persistent large PDA at 1 month of age.

Neonatal outcomes of extremely preterm infants from taiwan: comparison with Canada, Japan, and the USA

BACKGROUND

This study compared the current trend in survival rates and morbidity for very low birth weight (VLBW) infants in five Medical Training Centers of Prematurity for the Premature Baby Foundation of Taiwan (PBFT), with the outcomes from the USA, National Institute of Child Health and Human Development Neonatal Research Network (NICHD NRN), the Canadian Neonatal Network (CNN), and the Neonatal Research Network of Japan (NRNJ).

METHODS

The survival rates of VLBW infants according to gestational age (GA) and major morbidities were compared between networks (Taiwan, USA, Canada, and Japan). Taiwanese data for VLBW infants of GA ≤28 weeks between 2007 and 2012 were obtained from the "PBFT Annual Conferences of Premature Care" reports defining survival rate as neonates that survived to the time of discharge. Major morbidities included severe neurological injury (Grade 3 or 4 intraventricular hemorrhage or periventricular leukomalacia), bronchopulmonary dysplasia, severe retinopathy of prematurity, necrotizing enterocolitis, late-onset sepsis, and patent ductus arteriosus.

RESULTS

The survival rates of VLBW infants of GA ≤28 weeks from the PBFT (Taiwan), NICHD NRN (USA), CNN (Canada), and NRNJ (Japan) were 77% (1323/1718), 72% (6859/9575), 82% (2353/2872), and 89% (4489/5069), respectively. The annual survival rates in Taiwan from 2007 to 2012 were 72%, 76%, 76%, 74%, 77%, and 78%, respectively. When GA from ≤23 weeks to 28 weeks was assessed in Taiwan, the survival rates of VLBW infants according to each week were 22%, 50%, 70%, 80%, 88%, and 92%, respectively. The survival rate, especially at lower GAs, was highest in the NRNJ (Japan). The major difference between Taiwan and Japan was attributed to the lower survival rates at lower GA (≤26 weeks) in Taiwan. Japan had the lowest rates of major morbidities among the four countries.

CONCLUSION

The survival rate of VLBW infants has improved over the past 6 years in Taiwan. It is higher than the USA, but lower than Canada and Japan. However, the results from Taiwan are from five Medical Training Centers for the PBFT rather than from a population-based study. It is crucial to have a nationwide neonatal research network to develop new practical approaches for VLBW infants in Taiwan.

Efficacy of very low-dose prostaglandin E1 in duct-dependent congenital heart disease

AIM

The present study aims to define the lowest effective prostaglandin E1 dose in patients with inadequacy of pulmonary blood flow and/or intracardiac blood mixing and those with inadequate systemic blood flow.

METHODS

Patients with inadequacy of both pulmonary blood flow and/or blood mixing (Group 1) and those with inadequate systemic blood flow (Group 2) were retrospectively evaluated in two separate groups with regard to the prostaglandin E1 starting dose given in the referring facility, the lowest and the highest dose administered in our centre, treatment duration, adverse effects, and administered treatment.

RESULTS

No difference between the groups could be detected with respect to sex or birth weight (p=0.95 and 0.42, respectively). Group 1 and Group 2 were statistically similar in aspect of prostaglandin treatment duration (9.73±0.81 days versus 11.6±1.05 days, p=0.064). When compared with Group 2, the initial, maintenance and lowest efficient doses of prostaglandin E1 treatment were significantly lower and the titrated dose of prostaglandin E1 was significantly higher in Group 1 (p=0.001 for each).

CONCLUSION

Our findings indicate that the infusion of prostaglandin at a very low dose (0.003-0.005 mcg/kg/minute) is sufficient to maintain the patency of the ductus arteriosus. A higher dose of prostaglandin E1 may be necessary in patients with inadequate systemic blood flow.

Non-invasive measurements of ductus arteriosus flow directly after birth

OBJECTIVE

To assess ductus arteriosus (DA) blood flow directly after birth in healthy term infants after elective caesarean section.

DESIGN

In healthy term newborns, echocardiography was performed at 2, 5 and 10 min after birth to monitor cardiac output and DA blood flow. Heart rate (HR) was assessed using ECG.

SETTING

The delivery rooms of the Leiden University Medical Center.

PATIENTS

24 healthy term infants born after a caesarean section were included in this study.

RESULTS

Mean (SD) HR did not change (158 (18) beats per minute (bpm), 5 min (159 (23) bpm) and 10 min (156 (19) bpm). DA diameter decreased from 5.2 (1.3) mm at 2 min to 4.6 (1.3) mm at 5 min (p=0.01) to (3.9 (1.2) mm) (p=0.01) at 10 min. Right-to-left DA shunting was unaltered (median (IQR) 95 (64-154) mL/kg/min to 90 (56-168) mL/kg/min and 80 (64-120) mL/kg/min, respectively (ns)), whereas left-to-right shunting significantly increased between 2 and 5 min (41 (31-70) mL/kg/min vs 67 (37-102) mL/kg/min (p=0.01)) and increased significantly between 2 and 10 min (93 (67-125)) mL/kg/min (p<0.001). Right-to-left/left-to-right shunting ratio decreased significantly from 2.1 (1.4-3.1) at 2 min to 1.4 (1.0-1.8) at 5 min (p<0.0001) and to 0.9 (0.6-1.1) at 10 min (p<0.0001).

CONCLUSIONS

DA shunting changes swiftly from predominantly right-to-left shunting to predominantly left-to-right shunting at 10 min after birth, reflecting differential changes in pulmonary and systemic vascular resistance.

Use of ultrasound in the haemodynamic assessment of the sick neonate

Clinician performed ultrasound (CPU) by the clinician caring for a sick patient is increasingly used in critical care specialties. The real-time haemodynamic information obtained helps the clinician to understand underlying physiology, target treatment and refine clinical decision-making. Neonatologists are increasingly using ultrasound to assess sick neonates with a range of clinical presentations and demand for training and accreditation programmes is increasing. This review discusses the current expanded uses for CPU in the haemodynamic assessment of the sick neonate.

Comparison of oral ibuprofen with oral indomethacin for PDA closure in Indian preterm neonates: a randomized controlled trial

Oral ibuprofen is being used as an alternative to indomethacin in medical management of patent ductus arteriosus (PDA), but limited data exist on oral efficacy of these drugs for PDA closure in India. To assess and compare the efficacy of oral ibuprofen and oral indomethacin for PDA closure in preterm Indian neonates, we designed a randomized controlled study on clinically diagnosed and echocardiographically confirmed hemodynamically significant PDA in preterm neonates. Patients were assigned to receive either oral ibuprofen at a dosage of 10, 5, 5 mg/kg every 24 h or three doses of oral indomethacin (0.20-0.25 mg/kg every 24 h) starting on the third day of life or when diagnosed. A second course of ibuprofen/indomethacin was given, if PDA failed to close within 48 h after the first course. Patients were monitored for complications like oliguria, bleeding, necrotizing enterocolitis, intraventricular hemorrhage, oxygen dependency, and gastrointestinal side effects. The baseline characteristics were comparable in both groups. Of the 83 children enrolled, 57.8 % received oral ibuprofen and 42.1 % received oral indomethacin. The overall closure rate of PDA was 60 and 65.7 % in the ibuprofen and indomethacin groups, respectively. Closure rate was significantly higher when the drugs were administered at an early postnatal age (<8 days) (83.3 % [p = 0.02] in the indomethacin group and 75 % [p = 0.03] in the ibuprofen group) in neonates >28 weeks (ibuprofen group 66.7 % [p = 0.02]; indomethacin group 65.5 % [p = 0.04]) and in babies with birth weight >1,000 g (ibuprofen group 62.2 %; indomethacin group 70 % [p = 0.04 in both groups]). Complications were similar in both groups. The efficacy of both drugs was similar. Poor closure in our study could be because of genetic differences in pharmacokinetics of drug metabolism in the Indian population. Regimens with higher doses or increased duration of treatment may increase the frequency of closure. Studies with larger numbers of subjects with evaluation of pharmacokinetic parameters are therefore required.

Predictors of bronchopulmonary dysplasia or death in premature infants with a patent ductus arteriosus

BACKGROUND

Preterm infants with a patent ductus arteriosus (PDA) are at risk for death or development of bronchopulmonary dysplasia (BPD). However, PDA treatment remains controversial. We investigated if PDA treatment and other clinical or echocardiographic (ECHO) factors were associated with the development of death or BPD.

METHODS

We retrospectively studied clinical and ECHO characteristics of preterm infants with birth weight <1,500 g and ECHO diagnosis of a PDA. Logistic regression and classification and regression tree analyses were performed to assess variables associated with the combined outcome of death or BPD.

RESULTS

Of 187 preterm infants with a PDA, 75% were treated with indomethacin or surgical ligation and 25% were managed conservatively. Death or BPD occurred in 80 (43%) infants. The results of logistic regression analyses showed that lower gestational age (odds ratio (OR): 0.5), earlier year of birth during the study period (OR: 0.9), and larger ductal diameter (OR: 4.3) were associated with the decision to treat the PDA, whereas gestational age was the only variable associated with death or BPD (OR: 0.6; 95% confidence interval: 0.5-0.8).

CONCLUSION

Only lower gestational age and not PDA treatment or ECHO score was associated with the adverse outcome of death or BPD. Further investigation of PDA management strategies and effects on adverse outcomes of prematurity is needed.

Clinical and echocardiographic characteristics associated with the evolution of the ductus arteriosus in the neonate with birth weight lower than 1,500g

Objective:

To identify clinical and echocardiographic parameters associated with the evolution of the ductus arteriosus in neonates with birth weight lower than 1,500g.

Methods:

Retrospective study of 119 neonates in which clinical parameters (Prenatal: maternal age, risk of infection and chorioamnionitis, use of corticosteroid, mode of delivery and gestational age. Perinatal: weight, Apgar score, gender and birth weight/gestational age classification; Postnatal: use of surfactant, sepsis, fluid intake, heart murmur, heart rate, precordial movement and pulses, use of diuretics, oxygenation index, desaturation/apnea, ventilatory support, food intolerance, chest radiography, renal function, hemodynamic instability, and metabolic changes) and echocardiographic parameters (ductus arteriosus diameter, ductus arteriosus/weight ratio, left atrium/ aorta ratio, left ventricular diastolic diameter, and transductal flow direction, pattern and velocity) were analyzed. The clinical and echocardiographic parameters analyzed were considered statistically significant when p<0.05.

Results:

In the 119 neonates, the incidence of patent ductus arteriosus was 61.3%; 56 received treatment (46 pharmacological and 10 surgical treatment), 11 had spontaneous closure, 4 died, and 2 were discharged with patent ductus arteriosus. A higher incidence of chorioamnionitis, use of surfactant, lower weight and gestational age, sepsis, heart murmur, ventilatory support and worse oxygenation indices were observed in the neonates receiving treatment. The group with spontaneous closure had a smaller ductus arteriosus diameter, lower ductus arteriosus/weight ratio, and higher transductal flow velocity.

Conclusion:

Based on clinical and echocardiographic parameters, the neonates with spontaneous closure of the ductus arteriosus could be differentiated from those who required treatment.

Association of high levels of α-defensins and S100A proteins with Candida mannan detection in bronchoalveolar lavage fluid of preterm neonates

BACKGROUND

Candida mannan (Mn) detection in bronchoalveolar lavage fluid (BALF) was shown to be useful for earlier identification and preemptive therapy targeting in preterm infants at high risk of invasive Candida infection. We investigated whether early detection of Candida Mn in BALF is associated with the presence of some neutrophilic products, as markers of prenatal infection/inflammation.

METHODS

BALF specimens were collected during the first 48 h of life from mechanically ventilated preterm newborns. Samples were analyzed by high-performance liquid chromatography-electrospray ionization-mass spectrometry. The relative amounts of α-defensins 1-4 and S100A proteins were measured by extracted ion current peak area. Absolute and differential white cell counts in BALF were obtained. Mn antigen concentrations were determined by the Platelia Candida antigen kit.

RESULTS

Twenty-five studied neonates were divided into two groups: Mn-positive group and Mn-negative group. Levels of α-defensins 1-4 and S100A12 were significantly higher in the Mn-positive group than in the Mn-negative group. Moreover, positive significant correlations between the absolute number of neutrophils and the levels of α-defensins 1-4 and S100A8 were observed.

CONCLUSION

The detection of Mn antigen in BALF of preterm infants is consistent with evidence of an innate immune response in their lungs as demonstrated by higher levels of α-defensins and S100A proteins.

Perfusion index and its dynamic changes in preterm neonates with patent ductus arteriosus

AIM

The perfusion index (PI) and its dynamic change during respiration, and supressed the plethysmographic variability index (PVI), are calculated from pulse oximetry, and these indexes were recently proposed for continuous and noninvasive assessment of peripheral perfusion in neonates. We aimed to assess the effect of patent ductus arteriosus (PDA) on PI and PVI, according to ductal Doppler flow pattern.

METHODS

Forty-five neonates with median (Q25-75) gestational age (GA) and birthweight of 27 (25-28) weeks and 857 (750-1080) grams, respectively, were assessed prospectively using serial echocardiography and pulse oximetry during the first postnatal week.

RESULTS

Perfusion index increased from 0.70 (0.50-1.05) at day 1 to 1.50 (1.0-2.00) at day 7 (p < 0.01) and was not influenced by ductal flow pattern. PVI was 22 (18-27) and did not vary during the study period but differed according to ductal flow pattern, with lower values in the growing and pulsatile groups compared with the pulmonary hypertension (p < 0.05), closing and closed groups (p < 0.01).

CONCLUSIONS

Ductal persistence and flow pattern did not affect PI but did affect PVI in preterm neonates of less than 29 weeks of GA. Future studies are needed to establish the usefulness of PVI in the early detection and management of PDA in preterm neonates.