Patent ductus arteriosus evaluation by serial echocardiography in preterm infants

Echocardiography in the neonatal unit: current status and future prospects

INTRODUCTION

Traditionally echocardiography was used by pediatric cardiologists to diagnose congenital heart defects in neonates. Formalized neonatal hemodynamic fellowships have been established where neonatologists acquire advanced echocardiographic skills to gain anatomical, physiological, and hemodynamic information in real time and utilize this information in making a timely and accurate physiology-based clinical decision.

AREA COVERED

Differences between a comprehensive formal structural echocardiography, neonatologist performed targeted echocardiography and limited assessment on point-of-care-ultrasonography for specific indications have been covered. This article is focused at providing a comprehensive review of the status of echocardiography in the neonatal units, recent advancements and its future prospects in the neonatal intensive care units.

EXPERT OPINION

Comprehensive guidelines providing the scope of practice, a framework for training, and robust clinical governance process for the neonatologist performed targeted echocardiography have been established. In the last decade, echocardiography has emerged as essential vital bedside diagnostic tool in providing high-quality care to the sick infants in the neonatal units, and it has proved to improve the outcomes in neonates. It is now being considered as a modern hemodynamic monitoring tool. Advances in technology, machine learning, and application of artificial intelligence in applications of echocardiography seem promising adjunct tools for rapid assessment in emergency situations.

Should we "eliminate" PDA shunt in preterm infants? A narrative review

The patent ductus arteriosus frequently poses a significant morbidity in preterm infants, subjecting their immature pulmonary vascular bed to substantial volume overload. This, in turn, results in concurrent hypoperfusion to post-ductal organs, and subsequently alters cerebral blood flow. In addition, treatment has not demonstrated definitive improvements in patient outcomes. Currently, the optimal approach remains a subject of considerable debate with ongoing research controversy regarding the best approach. This article provides a comprehensive review of existing literature.

Patent ductus arteriosus and spontaneous intestinal perforation in a cohort of preterm infants

OBJECTIVE

To assess whether either duration and magnitude of ductal shunt or medical treatment for patent ductus arteriosus (PDA) are related to spontaneous intestinal perforation (SIP).

STUDY DESIGN

Clinical charts of infants <29 weeks' gestation born from 2006 to 2018 were reviewed. Echocardiographic examinations were evaluated according to McNamara and Sehgal's staging system.

RESULTS

A higher percentage of patients with SIP had a hemodynamically significant PDA (HSPDA) and was treated with either NSAIDs or paracetamol (79% vs 53% and 81% vs 54%, respectively). Among non-treated patients, we found a 1.32 increase in the odds of SIP per day of persistence of HSPDA. In the cohort of patients treated despite the absence of HSPDA, we found a 2.35 increase in the odds of SIP per dose of drug administered.

CONCLUSION

Both treating a non-HSPDA and leaving a HSPDA to its natural history seem to be associated with SIP.

Sex Differences in Patent Ductus Arteriosus Incidence and Response to Pharmacological Treatment in Preterm Infants: A Systematic Review, Meta-Analysis and Meta-Regression

A widely accepted concept in perinatal medicine is that boys are more susceptible than girls to complications of prematurity. However, whether this ‘male disadvantage of prematurity’ also involves persistent patent ductus arteriosus (PDA) has been scarcely investigated. Our aim was to conduct a systematic review and meta-analysis on studies addressing sex differences in the risk of developing PDA among preterm infants. We also investigated whether the response to pharmacological treatment of PDA differs between boys and girls. PubMed/Medline and Embase databases were searched. The random-effects male/female risk ratio (RR) and 95% confidence interval (CI) were calculated. We included 146 studies (357,781 infants). Meta-analysis could not demonstrate sex differences in risk of developing any PDA (37 studies, RR 1.03, 95% CI 0.97 to 1.08), hemodynamically significant PDA (81 studies, RR 1.00, 95% CI 0.97 to 1.02), or in the rate of response to pharmacological treatment (45 studies, RR 1.01, 95% CI 0.98 to 1.04). Subgroup analysis and meta-regression showed that the absence of sex differences was maintained over the years and in different geographic settings. In conclusion, both the incidence of PDA in preterm infants and the response rate to pharmacological treatment of PDA are not different between preterm boys and girls.

A Novel Patent Ductus Arteriosus Severity Score to Predict Clinical Outcomes in Premature Neonates

Background: Patent Ductus Arteriosus (PDA) in premature neonates has been associated with comorbidities including chronic lung disease (CLD), and death. However, the treatment of PDA remains controversial. There have been several echocardiographic variables previously used to determine the hemodynamic significance of PDA but their utility in early prediction of clinical outcomes is not well studied. Objective: The objective of our study was to evaluate the use of a severity scoring system incorporating markers of systemic under perfusion, pulmonary over perfusion and left ventricular (LV) function in predicting clinical outcomes in premature neonates. Methods: It is a single center prospective observational study involving newborns < 32 weeks’ gestation. An echocardiogram was done within seven days of life to measure variables previously known to predict severity of shunting in PDA including pulmonary perfusion index (PPI). Predictors of CLD/death were identified using multivariate logistic regression. A severity score was derived and its ability to predict clinical outcomes was tested using a receiver operating characteristic curve. Results: We studied 98 infants with a mean (SD) gestation of 28.9 ± 1.91 weeks and birth weight of 1228.06 ± 318.94 g, respectively. We identified five echocardiographic variables along with gestational age that was independently associated with the outcome variable (PPI, LV output, Superior Mesenteric Artery [SMA] Velocity Time Integral [VTI], Peak diastolic flow velocity in Pulmonary Vein [PV Vd], and reversal of flow in diastole in descending aorta [DFR]). The range of severity score was 0 (low risk) to 12 (high risk). A higher score was associated with the primary outcome variable of CLD/death (7.5 [1.2] vs. 3.6 [1.5], p < 0.001). Our severity score had an area under the curve of 0.97 (95% CI 0.93−0.99, p < 0.001) for predicting CLD/death. Conclusion: Our new PDA severity score of 5.5 has a sensitivity and specificity of 94% and 93%, and positive and negative predictive values of 94% and 93%, respectively.

Relationship of Patent Ductus Arteriosus Echocardiographic Markers With Descending Aorta Diastolic Flow

OBJECTIVES

To characterize the relationship of echocardiographic markers of left heart overload and flow in peripheral major end-organ vessels (eg, celiac artery) with the presence of reversed holodiastolic flow in the descending aorta, considered a surrogate marker of an increased transductal shunt volume, in preterm patients with a patent ductus arteriosus (PDA).

METHODS

This work was a retrospective study of data from echocardiography performed to investigate the hemodynamic significance of a PDA in preterm patients. We studied differences in echocardiographic markers of the PDA shunt volume according to patterns of flow in the postductal descending aorta (no PDA, PDA with antegrade diastolic flow, and PDA with reversed diastolic flow). The strength of the association between each echocardiographic marker and the presence of aortic holodiastolic flow reversal was investigated.

RESULTS

We studied 137 patients with a median (interquartile range) birth weight of 850 (694-1030) g and a median gestational age of 25 (24-27) weeks. Among patients with a PDA (113), those with diastolic flow reversal in the descending aorta (44) presented had increased echocardiographic markers representative of the shunt volume (increased left ventricular output, left atrial-to-aortic ratio, pulmonary vein D wave, and shorter isovolumic relaxation time) compared to those with aortic antegrade diastolic flow. A positive, albeit weak, correlation between diastolic flow reversal and shunt volume echocardiographic markers was found. Abnormal diastolic flow in the celiac artery had the strongest correlation (R²  = 0.24).

CONCLUSIONS

In preterm patients with a PDA, echocardiographic markers of the shunt volume were more abnormal in patients with reversed diastolic flow in the descending aorta. These data support the assumption that variance in these markers are related to the shunt volume, which needs consideration when adjudicating hemodynamic significance.

A Framework for AI-Assisted Detection of Patent Ductus Arteriosus from Neonatal Phonocardiogram

The current diagnosis of Congenital Heart Disease (CHD) in neonates relies on echocardiography. Its limited availability requires alternative screening procedures to prioritise newborns awaiting ultrasound. The routine screening for CHD is performed using a multidimensional clinical examination including (but not limited to) auscultation and pulse oximetry. While auscultation might be subjective with some heart abnormalities not always audible it increases the ability to detect heart defects. This work aims at developing an objective clinical decision support tool based on machine learning (ML) to facilitate differentiation of sounds with signatures of Patent Ductus Arteriosus (PDA)/CHDs, in clinical settings. The heart sounds are pre-processed and segmented, followed by feature extraction. The features are fed into a boosted decision tree classifier to estimate the probability of PDA or CHDs. Several mechanisms to combine information from different auscultation points, as well as consecutive sound cycles, are presented. The system is evaluated on a large clinical dataset of heart sounds from 265 term and late-preterm newborns recorded within the first six days of life. The developed system reaches an area under the curve (AUC) of 78% at detecting CHD and 77% at detecting PDA. The obtained results for PDA detection compare favourably with the level of accuracy achieved by an experienced neonatologist when assessed on the same cohort.

Functional echocardiography training in the neonatal intensive care unit: comparing measurements and results with the pediatric cardiologist

OBJECTIVES

Functional echocardiography is a valuable tool in the neonatal intensive care unit, but training programs are not standardized. The aim was to report an functional echocardiography training program for neonatologists and to describe the agreement of their measurements with the pediatric cardiologist.

METHODS

Functional echocardiography training lasted 32h. After training program, the neonatologists performed functional echocardiography in the neonatal intensive care unit and were required to measure left cardiac chambers dimensions, left ventricle systolic function, right and left ventricular output, ductus arteriosus diameter, and flow pattern. Images were recorded by the equipment and reviewed offline by the pediatric cardiologist. The Bland-Altman test was used for quantitative variables and the kappa test, for qualitative variables.

RESULTS

Twenty-two trained neonatologists performed 100 functional echocardiography exams. Ductus arteriosus identification and flow pattern had substantial agreement (kappa=0.91 and 0.88, respectively), as well as its diameter (mean difference=0.04mm). The mean difference for the aortic root was -1.2mm; left atrium, 0.60mm; left ventricle diastolic diameter, -0.90mm; left ventricle systolic diameter, -0.30mm. Shortening fraction and ejection fraction correlated well with broad limits of agreement, -2.96% (14.88; -20.82%) and --3.43% (15.54; -22.40%), respectively. Right and left ventricular output had broad limits of agreement, 16.69mL/kg/min (222.76; -189.37) and 23.57mL/kg/min (157.88; -110), respectively. There was good agreement between interpretations of normal or low cardiac output (76.7% for right ventricular output; 75.7% for left ventricular output).

CONCLUSION

This functional echocardiography training program enabled neonatologists to obtain adequate skills in performing the images, obtaining good agreement with the cardiologist in simple hemodynamic measurements and ductus arteriosus evaluation.

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.

Moving Beyond the Stethoscope: Diagnostic Point-of-Care Ultrasound in Pediatric Practice

Diagnostic point-of-care ultrasound (POCUS) is a growing field across all disciplines of pediatric practice. Machine accessibility and portability will only continue to grow, thus increasing exposure to this technology for both providers and patients. Individuals seeking training in POCUS should first identify their scope of practice to determine appropriate applications within their clinical setting, a few of which are discussed within this article. Efforts to build standardized POCUS infrastructure within specialties and institutions are ongoing with the goal of improving patient care and outcomes.

Practice for preterm patent ductus arteriosus; focusing on the hemodynamic significance and the impact on the neonatal outcomes

Hemodynamically significant preterm patent ductus arteriosus (PDA) affects mortality; comorbidities such as necrotizing enterocolitis, intraventricular hemorrhage, and bronchopulmonary dysplasia; and adverse long-term neurodevelopmental outcomes in preterm infants, particularly in very low birth weight infants. However, recent studies have indicated that there is no consensus on the causal relationship between PDA and neonatal outcomes, the benefit of PDA treatment, the factors guiding the need for treatment, and optimal treatment strategies. Such uncertainty has resulted in wide variations in practice for treating preterm PDA between units, regions, and nations. Nowadays, there has been a paradigm shift to more conservative treatment for preterm PDA, and suggestions regarding selective management of preterm PDA considering risk factors and hemodynamic significance are increasing. Neonatologist-performed echocardiography and advances in modalities to assess hemodynamic significance such as biologic markers and near-infrared spectroscopy also help improve the efficacy of selective treatment of preterm PDA.

Patent ductus arteriosus: The physiology of transition

The transition from intrauterine to extrauterine life represents a critical phase of physiological adaptation which impacts many organ systems, most notably the heart and the lungs. The majority of term neonates complete this transition without complications; however, dysregulation of normal postnatal adaptation may lead to acute cardiopulmonary instability, necessitating advanced intensive care support. Although not as well appreciated as changes in vascular resistances, the shunt across the DA plays a crucial physiologic role in the adaptive processes related to normal transitional circulation. Further, we describe key differences in the behavior of the ductal shunt during transition in preterm neonates and we postulate mechanisms through which the DA may modulate major hemodynamic complications during this vulnerable period. Finally, we describe the conditions in which preservation of ductal patency is a desired clinical goal and we discuss clinical factors that may determine adequate balance between pulmonary and systemic circulation.

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.

Trends in the neurodevelopmental outcomes among preterm infants from 2003-2012: a retrospective cohort study in Japan

OBJECTIVES

To determine the trends in mortality and the prevalence of abnormal neurodevelopmental outcomes among preterm Japanese infants.

STUDY DESIGN

A retrospective multicenter cohort of 30,793 preterm infants born at a gestational age ≤32 weeks, between 2003 and 2012, in the Neonatal Research Network, Japan, was evaluated in the primary analysis. Finally, 13,661 infants were followed-up until 3 years of age and evaluated for neurodevelopmental outcomes, including cerebral palsy (CP), home oxygen therapy (HOT) use, and visual, hearing, and cognitive impairments. Multivariable logistic regression analysis was performed to determine the risk-adjusted trends in mortality and long-term neurodevelopmental outcomes.

RESULTS

The trends in overall mortality (adjusted odds ratio, (AOR): 0.92; 95% confidence interval, (CI): 0.89-0.94), the prevalence of CP (AOR: 0.95, 95% CI: 0.92-0.98), HOT use (AOR: 0.84, 95% CI: 0.75-0.93), and visual (AOR: 0.84, 95% CI: 0.81-0.87) and hearing impairments (AOR: 0.78, 95% CI: 0.63-0.97) showed a significant downward trend, while cognitive impairment showed no significant changes (AOR: 1.02, 95% CI: 0.99-1.05). Intravenous hyperalimentation was significantly correlated with visual impairment (AOR 0.74, 95% CI 0.59-0.91). Early establishment of enteral feeding was associated with improved long-term outcomes.

CONCLUSIONS

Mortality was improved, and this did not lead to increased risks for abnormal neurodevelopmental outcomes. Nutritional support might improve long-term neurodevelopmental outcomes.

Neonatologist-performed point-of-care functional echocardiography in the neonatal intensive care unit

Functional echocardiography (fECHO) refers to a bedside, limited assessment of the ductus arteriosus, myocardial performance and pulmonary or systemic haemodynamics that is brief in nature and addresses a specific clinical question or management dilemma. This point-of-care ultrasonography is increasingly used internationally and locally among neonatal units to assist with management of neonatal haemodynamic conditions. This article intends to explain the modality, its indications, interpretation and implications for management, and how it impacts long-term outcomes, particularly in chronic lung disease for premature infants born before 32 weeks of gestation. This review will focus on fECHO as a clinical tool to assess the haemodynamics of sick neonates and how it assists in the logical choice for cardiovascular support. Training should be approached as a combined effort between the paediatric cardiology service and neonatology service.

Neonatal outcome in preterm deliveries before 34-week gestation - the influence of the mechanism of labor onset

Purpose: To evaluate neonatal outcomes in preterm infants with less than 34 weeks after spontaneous labor, preterm premature rupture of membranes (PPROM) or iatrogenic delivery and to clarify whether the mechanism of labor onset is a risk factor for adverse short-term neonatal outcome. Methods: We performed a retrospective case-control study, which included 266 preterm newborns with less than 34-week gestation, between 2011 and 2015. Neonatal outcomes were compared according to the mechanism of labor onset. Our primary outcomes were neonatal death, sequelae on hospital discharge and a composite of these two variables (combined neonatal outcome). Results: Compared to spontaneous preterm labor, iatrogenic preterm newborns were at increased risk of respiratory distress syndrome (RDS) [Odds Ratio (OR) 3.05 (95%CI 1.31; 7.12)], and need of exogenous surfactant administration [OR 3.87 (95%CI 1.60; 9.35)]. PPROM was associated with higher risk of neonatal sepsis [OR 12.96 (95%CI 1.18; 142.67)]. There were no differences regarding the combined outcome for iatrogenic [OR 0.94 (95%CI 0.33; 2.71)] or PPROM [OR 1.11 (95%CI 0.35; 3.49)] groups. Conclusions: In our study, the different mechanisms of labor onset are associated with different neonatal outcomes. Iatrogenic preterm birth was associated with an increased risk of RDS and a higher need of exogenous surfactant administration than spontaneous group. The rate of neonatal sepsis was significantly higher in PPROM group along with a higher prevalence of histological chorioamnionitis.

Acute kidney injury in preterm neonates with ≤30 weeks of gestational age and its risk factors

BACKGROUND

Acute kidney injury (AKI), an abrupt decline in kidney function, is a challenging diagnosis among preterm infants due to some specific features of this population. The aim of this study was to determine the risk factors of developing AKI and the predictive factors for its severity in preterm neonates with less than 31 weeks of gestational age.

METHODS

All neonates with less than 31 weeks of gestational age, admitted in our NICU between January 2012 and December 2015, were included. Maternal and neonatal records about demographics, placental abnormalities, perinatal and neonatal period and evolution in NICU, as well as electrolytic analysis and serum creatinine and urea values during their hospitalization were retrospectively collected and analyzed.

RESULTS

A total of 106 neonates were included. Of those, 24 were diagnosed with AKI, resulting in a prevalence of 22.6%, and 82 were used as controls. Gestational age (OR=0.39; 95% CI=0.2-0.76; P=0.006), congenital malformations (OR=36.93; 95%CI=2.48-550.59; P=0.009), vasoactive drugs (OR=27.06; 95%CI=3.58-204.45; P=0.001), nonsteroidal anti-inflammatory drugs (OR=9.61; 95%CI=1.78-51.73; P=0.008) and sepsis (OR=7.78; 95%CI=1.32-46.04; P=0.024) were found to be independent risk factors. Cardiac surgery was a predictive factor for AKI severity (OR=25; 95%CI=2.09-298.29; P=0.011). The mortality rate in the AKI group was 41.7%.

CONCLUSIONS

AKI in preterm neonates is an important feature that contributes to increase the mortality in NICUs. Thus, it is crucial to know its risk factors to establish prompt diagnosis and prevention and, in this way, be able to improve the prognosis.

Application of NPE in the assessment of a patent ductus arteriosus

In many preterm infants, the ductus arteriosus remains patent beyond the first few days of life. This prolonged patency is associated with numerous adverse outcomes, but the extent to which these adverse outcomes are attributable to the hemodynamic consequences of ductal patency, if at all, has not been established. Different treatment strategies have failed to improve short-term outcomes, with a paucity of data on the correct diagnostic and pathophysiological assessment of the patent ductus arteriosus (PDA) in association with long-term outcomes. Echocardiography is the selected method of choice for detecting a PDA, assessing the impact on the preterm circulation and monitoring treatment response. PDA in a preterm infant can result in pulmonary overcirculation and systemic hypoperfusion, Therefore, echocardiographic assessment should include evaluation of PDA characteristics, indices of pulmonary overcirculation with left heart loading conditions, and indices of systemic hypoperfusion. In this review, we provide an evidence-based overview of the current and emerging ultrasound measurements available to identify and monitor a PDA in the preterm infant. We offer indications and limitations for using Neonatologist Performed Echocardiography to optimize the management of a neonate with a PDA.

The impact of intrauterine growth restriction on respiratory outcomes

BACKGROUND

Intrauterine growth restriction (IUGR) is caused by fetal growth below what is normal for its genetic potential. Recent studies have shown a distinct association between changes in umbilical artery flow in IUGR subjects and an increased risk of respiratory morbidity and consequently, higher mortality. The aim of this study was to find the impact of IUGR on the respiratory outcomes of premature neonates born with less than 32 weeks gestational age.

METHODS

This retrospective cohort study targeted infants born with less than 32 weeks of gestation, admitted at NCIU, between January 2010 and December 2016. Each selected IUGR case was matched according to gestational age and sex with an appropriate birthweight newborn at a 1:2 ratio, within a 12-month period.

RESULTS

The study involved 126 neonates, 42 with IUGR, and 84 control subjects. IUGR was not identified as a predictor of Bronchopulmonary Dysplasia (BDP) (OR 4.80, 95% CI: 1.14-20.21, P=0.033). Abnormal umbilical artery flow (OR 4.80, 95% CI: 1.14-20.21, P=0.033) and late onset sepsis (OR 3.31, 95% CI: 1.04-10.56, P=0.044) were significantly associated with BDP.

CONCLUSIONS

It is essential to recognize changes in the umbilical artery flow, especially in high-risk pregnancies such as IUGR, since these represent an a priori risk marker for the development of BDP. The individual and combined effect of IUGR, alterations on umbilical artery flow and extreme prematurity has not yet been completely clarified on the impact on lung morbidity, requiring a larger number of studies.

Hemodynamic Assessment and Monitoring of Premature Infants

The management of the hemodynamic status of critically ill preterm infants, particularly around the periviable period, remains a significant challenge in the neonatal intensive care unit for a multitude of reasons. The causes of hemodynamic compromise in this population are heterogeneous and usually superimposed on the complex physiologic processes that occur during transition from fetal to neonatal life. This review outlines the unique nature of low blood flow states in this population and present an overview of the current methods for identification and assessment of hemodynamic compromise.

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.

Morbidity and mortality of preterm infants less than 26 weeks of gestational age

BACKGROUND

Extreme preterm infants have a high risk of morbidity and mortality. Newborns delivered between 23+0 and 25+6 weeks, are considered to be in the "gray zone" and have uncertain prognosis. For these children medical decision-making becomes complex and controversial. The present study intends to evaluate the neonatal morbidity and mortality of preterm infants born between 23 weeks and 25+6 weeks of gestational age.

METHODS

A retrospective study was conducted including all inborn preterm infants, with a gestational age between 23+0 and 25+6 weeks, admitted to a level IIIC NICU, between January 1st, 1996 and December 31st, 2014.

RESULTS

A total of 72 preterm neonates were included, 18.1% had a full cycle of antenatal steroids. The most frequent major morbidities were RDS (95.4%), patent ductus arteriosus (81.3%), sepsis (55.7%, being 19.7% early sepsis, and 36.1% late sepsis), intraventricular hemorrhage (34.4%), retinopathy of prematurity (21.9%) and necrotizing enterocolitis (10.9%). Fifty-four (75%) children died. The only factor adjusted to age associated with high mortality founded was hypotension (OR=4.99, P<0.019). Morbidity at discharge was: severe bronchopulmonary dysplasia (77.8%), retinopathy of prematurity (72.2%), intraventricular hemorrhage (16.7%), cystic periventricular leukomalacia (11.1%), and sequalae of necrotizing enterocolitis (5.6%).

CONCLUSIONS

The survival rate was 25% and a high morbidity at discharge was observed, which leave us with the huge responsibility to improve this result in a near future. Extreme prematurity is still a very controversial and complex issue and particular challenge for neonatologists. The use of antenatal steroid in the more immature preterm infants should be encouraged.

Use of Targeted Neonatal Echocardiography and Focused Cardiac Sonography in Tertiary Neonatal Intensive Care Units: Time to Embrace It?

Focused cardiac sonography and targeted neonatal echocardiography refer to goal-directed cardiac imaging using ultrasound, typically by noncardiologic specialists. Although the former consists of a rapid qualitative assessment of cardiac function, which is usually performed by acute care practitioners, the latter refers to detailed functional echocardiography to obtain quantitative and qualitative indexes of pulmonary and systemic hemodynamics in sick neonates and is typically performed by neonatologists. Although the use of these modalities is increasing, they still remain unavailable in most North American centers providing acute care to neonates, partly because of limited data regarding their direct impact on patient care. Here we present a series of 5 cases from a large perinatal unit in which immediate availability of relevant expertise led to important and arguably life-saving clinical interventions. In 4 of these cases, focused cardiac sonography was sufficient to make the diagnosis, whereas in 1 case, clinical integration of detailed systemic hemodynamics measured on target neonatal echocardiography was required.

[Functional echocardiography in the neonatal intensive care unit; experience in a tertiary level hospital]

BACKGROUND

The Hospital Infantil de Mexico Federico Gómez is a tertiary level hospital with a neonatal intensive care unit (NICU), which is one of the most important units in the treatment of newborn's diseases in México. In this unit, the decisions are taken based on some clinic parameters such as respiratory rate, heart rate, arterial pressure, urinary output and lactate levels. The functional echocardiography is a useful tool which improves the hemodynamic evaluation and decisions in neonatal care. Data on its use in neonatal units in Mexico is lacking.

METHODS

A prospective study conducted in NICU patients during 3 months from August to October 2015 at the Hospital Infantil de Mexico Federico Gómez. Gestational age, birth weight, admission criteria, days of life at examination, indication for functional echocardiography and changes in treatment were evaluated and finally, we performed a new study 24hours later. Echocardiographic evaluation included: assessment of presence/hemodynamic significance of PDA; myocardial function: ejection fraction/shortening fraction, left ventricular output, right ventricular output, systemic blood flow; and signs of pulmonary hypertension.

RESULTS

30 echocardiographic studies were performed in 15 patients. The average age was 9.6 days, the variability in gestational ages were 37 to 42 weeks; the average weight was 2.583kg. The most frequent diagnosis was respiratory distress, and the principal indications for echocardiography were hemodynamic instability and sepsis (53.3%). In 11 cases (73.3%), the treatment was modified posteriorly to functional echocardiography, and in 10 cases we observed improvements in the 24hours after control.

CONCLUSIONS

Functional echocardiography is a useful tool in NICU, which may assist with clinical decision-making.

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.

[Functional echocardiography in neonatal intensive care: 1 year experience in a unit in Spain]

INTRODUCTION

Several publications highlight the usefulness of functional echocardiography (FnECHO) in neonatal intensive care. Data is lacking on its use in units neonatal in Spain.

OBJECTIVES

To evaluate frequency of use, patient characteristics, indications, measurements, and impact on patient management of FnECHO in a neonatal intensive care unit (NICU) in Spain over a 1 year period.

METHODS

A retrospective study conducted in NICU patients during 1 year.

VARIABLES

gestational age, birthweight, admission criteria, days of life at examination, indication for FnECHO, parameters assessed, and treatment modifications.

RESULTS

168 echocardiographic studies were performed in 50 patients (mean 3,4. SD 2,83). The most frequent indication was patent ductus (PDA) assessment (58.3%), followed by hemodynamic instability (22.2%). The results of FnECHO modified treatment in 62 cases (36.9%). In 17.4% of them treatment with ibuprofen was initiated, and in 1.2% it was discontinued. In 10.8% of the cases, the results of FnECHO modified hemodynamic support. Echocardiographic evaluation included: assessment of presence/hemodynamic significance of PDA (100%); myocardiac function: ejection fraction/shortening fraction (EF/SF) 23.8%, left ventricular output 24.4%, right ventricular output 21.4%, systemic blood flow 42.3%; and signs of pulmonary hypertension 7.7%.

CONCLUSIONS

FnECHO is frequently used in the NICU, and in many cases it guides treatment. PDA assessment and hemodynamic instability are the most frequent indications. It still needs to be elucidated if the use of FnECHO modifies patient outcomes.

Serial echocardiography in very preterm infants: a pilot randomized trial

AIM

To determine whether routine echocardiography increases diagnosis and treatment for patent ductus arteriosus (PDA) and whether randomized nondisclosure is a feasible strategy for studying PDA management.

METHODS

Two-centre, pilot randomized, controlled trial. 88 infants with birth weights ≤1250 grams and gestational ages ≤30 weeks were randomized to disclosure or nondisclosure of serial echocardiogram findings. Echocardiograms were performed at 3-5 and 7-10 days of life. The primary outcome was time to regain birth weight.

RESULTS

100% of echocardiograms in the disclosure group were disclosed; 16% (echocardiogram #1) and 29% (echocardiogram #2) were disclosed in the nondisclosure group. There was a statistically nonsignificant decrease in drug therapy for PDA in the nondisclosure group (adjusted odds ratio [AOR] 0.56, 95% confidence interval [CI] 0.24-1.34). There was no difference in time to regain birth weight or in other important neonatal outcomes. However, infants in the nondisclosure group were more likely to demonstrate appropriate weight loss and then regain birth weight within 7-14 days (AOR 2.64, 95% CI 1.08-6.44).

CONCLUSION

Randomized nondisclosure of echocardiograms is a feasible strategy for evaluation of approaches to PDA management in very preterm infants. Avoidance of routine echocardiography may reduce drug therapy for PDA without adverse clinical effects.

Morbidity and mortality in preterm neonates with patent ductus arteriosus on day 3

OBJECTIVE

To assess the association between a patent ductus arteriosus (PDA) on day 3 of life and severe morbidity and mortality.

DESIGN

Cohort study.

SETTING

Neonatal Intensive Care Unit, Aarhus University Hospital, Denmark.

PATIENTS

All neonates with a gestational age less than 32 weeks admitted from 2010 to 2012.

INTERVENTIONS

All neonates (n=183) were routinely screened with echocardiography for PDA on day 3 of life. Information on baseline characteristics and outcome was collected by structured coding sheets and medical records.

MAIN OUTCOME MEASURES

The association among PDA diameter and pulmonary haemorrhage, intraventricular haemorrhage (IVH), necrotising enterocolitis, bronchopulmonary dysplasia (BPD), death, and the composite outcome of death or severe morbidity was assessed.

RESULTS

In neonates, born prior to 28 gestational weeks, a PDA on day 3 of life was associated with a threefold increase in odds of death or severe morbidity compared with neonates without PDA (OR=3.4; CI 1.1 to 11). The odds were highest in neonates with a large PDA (diameter ≥1.5 mm). Neonates with a large PDA were also found to have increased odds of IVH (OR 4.2; CI 1.3 to 14) and BPD (OR 3.7; CI 1.0 to 14) compared with neonates with no PDA.

CONCLUSIONS

In neonates born with a gestational age below 28 weeks the presence of a PDA on day 3 of life was associated with adverse outcome; this association was even more pronounced with a large PDA. Thus, early echocardiography may facilitate the identification of neonates suitable for a targeted approach to intervention in future randomised controlled trials.

Targeted neonatal echocardiography (TnECHO) service in a Canadian neonatal intensive care unit: a 4-year experience

OBJECTIVE

To characterize the effect of a targeted neonatal echocardiography (TnECHO) program on decision making in a tertiary level unit.

STUDY DESIGN

Retrospective cohort study of neonates, admitted between September 2007 and April 2011. Details of the TnECHO, and the clinical decisions within 6 h of the consultation were recorded.

RESULT

A total of 199 infants underwent 512 echocardiograms with a median (interquartile range) of 2 (1 to 3) TnECHO studies per infant. The indications included assessment for patent ductus arteriosus (PDA; n=261, 51%), post-PDA ligation assessment (n=101, 19%), pulmonary hemodynamics (n=81, 16%), myocardial performance and systemic blood flow (n=52, 10%), and central venous catheter tip position (n=6, 1%). TnECHO consultation was followed by a change in clinical management in 212 cases (41%) and avoidance of a planned intervention in 112 cases (22%).

CONCLUSION

TnECHO may be a useful tool to guide clinical decisions in the neonatal intensive care unit setting. Well-planned prospective studies are needed to assess the impact of TnECHO on outcomes.

Comparison of mortality and morbidity of very low birth weight infants between Canada and Japan

OBJECTIVE

To compare neonatal outcomes of very low birth weight (VLBW) infants admitted to NICUs participating in the Canadian Neonatal Network and the Neonatal Research Network of Japan.

METHODS

Secondary analyses of VLBW infants in both national databases between 2006 and 2008 were conducted. The primary outcome was a composite of mortality or any major morbidity defined as severe neurologic injury, bronchopulmonary dysplasia, necrotizing enterocolitis, or severe retinopathy of prematurity at discharge. Secondary outcomes included individual components of primary outcome and late-onset sepsis. Logistic regression adjusting for confounders was performed.

RESULTS

A total of 5341 infants from the Canadian Neonatal Network and 9812 infants from the Neonatal Research Network of Japan were compared. There were higher rates of maternal hypertension, diabetes mellitus, outborn, prenatal steroid use, and multiples in Canada, whereas cesarean deliveries were higher in Japan. Composite primary outcome was better in Japan in comparison with Canada (adjusted odds ratio [AOR] 0.87, 95% confidence interval [CI] 0.79-0.96). The odds of mortality (AOR 0.40, 95% CI 0.34-0.47), severe neurologic injury (AOR 0.57, 95% CI 0.49-0.66), necrotizing enterocolitis (AOR 0.23, 95% CI 0.19-0.29), and late-onset sepsis (AOR 0.22, 95% CI 0.19-0.25) were lower in Japan; however, the odds of bronchopulmonary dysplasia (AOR 1.24, 95% CI 1.10-1.42) and severe retinopathy of prematurity (AOR 1.98, 95%CI 1.69-2.33) were higher in Japan.

CONCLUSIONS

Composite outcome of mortality or major morbidity was significantly lower in Japan than Canada for VLBW infants. However, there were significant differences in various individual outcomes identifying areas for improvement for both networks.

Cardiovascular support in preterm infants: a survey of practices in Australia and New Zealand

AIM

Management of haemodynamic instability in premature neonates and selection of inotropic therapy are protocol driven, and therapeutic choices lack scientific validation. The aim of this study was to characterise practices related to the management of haemodynamic instability in premature infants.

METHODS

An electronic web-based questionnaire was emailed to all neonatologists and advanced trainees in Australia and New Zealand. Respondents were presented with a series of questions related to the management of hypotension in a 1-day-old, extremely low birthweight infant, and opinions were collected.

RESULTS

Survey response rate was 65% (114/176). Haemodynamically significant ductus arteriosus, systemic blood flow and left ventricular afterload were considered the most important physiologic concepts by 81, 68 and 50%, respectively. After initial crystalloid replacement, the next step in management reported included a second bolus (35%), dobutamine (28%), dopamine (17%) or clinician-performed cardiac ultrasound (CPCU) (20%). In the setting of hypotension resistant to dobutamine and dopamine, the most common strategies were to perform CPCU (57%), or administer hydrocortisone (39%), epinephrine (3.5%) or milrinone (<1%). The majority (66%) of respondents felt that premature infants are over-treated on the basis of presumed hypotension, while 83% felt that performing a CPCU would enhance clinical decision-making.

CONCLUSIONS

Wide variation in the approach to management of haemodynamic instability in extremely low birthweight infants was identified. Haemodynamic information provided by a CPCU was considered highly desirable by the majority of the respondents.

The ductus arteriosus: a refined approach!

Although ongoing patency of the ductus arteriosus is common in small extremely preterm infants, consensus is lacking regarding its clinical significance and treatment strategies. Literature regarding likelihood of spontaneous closure, impact on neonatal morbidity and long-term outcomes, and adverse effects of intervention has led to uncertainty as to the best course of action. Enhancing the determination of hemodynamic significance and refining patient selection for therapeutic intervention will streamline the decision-making process. Targeted neonatal echocardiography performed by the clinician has gained popularity worldwide, and preliminary data show that it has the potential to optimize patient outcomes. We review the arguments for and against medical and surgical therapy, explore how targeted neonatal echocardiography used in conjunction with biomarkers may refine the treatment approach, and consider future directions in the field.

Haemodynamically unstable preterm infant: an unresolved management conundrum

While extremely low-birthweight infants are at a higher risk of haemodynamic instability, management strategies can be highly variable and may lack scientific validation. The aetiology of cardiovascular compromise can be diverse. Volume replacements, cardiotropes (dobutamine, dopamine, epinephrine and milrinone) and hydrocortisone supplementation are common interventions. Most often, therapy is driven by protocol, is based on poorly validated clinical information or is based on the premise that "one therapy fits all". A physiology-driven approach is most needed during transition from intrauterine to extrauterine life surrounding preterm birth, when rapid changes in cardiovascular adaptation occur. The physiologically important determinants of neonatal haemodynamics include cardiac output and systemic vascular resistance, blood pressure, as well as individual organ vascular resistances and blood flows. Three key variables with impact on neonatal haemodynamics, haemodynamically significant ductus arteriosus, systemic blood flow and left ventricular afterload, as well as related therapeutic dilemmas are addressed. Among the novel technologies and approaches presently available, targeted neonatal echocardiography performed by the clinician, used in conjunction with the clinical context, has the potential to better define pathophysiology. A framework for physiology-driven care is proposed, which has the potential to optimize care.

Patent ductus arteriosus in preterm infants

Patent ductus arteriosus (PDA) is a major morbidity in preterm infants, especially in extremely premature infants less than 28 weeks. The clinical signs and symptoms of PDA in preterm infants are non specific and insensitive for making an early diagnosis of significant ductal shunting. Functional echocardiography is emerging as a new valuable bedside tool for early diagnosis of hemodynamically significant ductus, even though there are no universally accepted criteria for grading the hemodynamic significance. Echocardiography has also been used for early targeted treatment of ductus arteriosus, though the long term benefits of such strategy are debatable. The biomarkers like BNP and N terminal pro BNP are currently under research as diagnostic marker of PDA. The primary mode of treatment for PDA is pharmacological closure using cyclo-oxygenase inhibitors with closure rate of 70-80%. Oral ibuprofen is emerging as a better alternative especially in Indian scenario where parenteral preparations of indomethacin are unavailable and side effects are comparatively lesser. Though pharmacological closure of PDA is an established treatment modality, there is still lack of evidence for long term benefits of such therapy as well as there is some evidence for the possible adverse effects like increased ROP and BPD rates, especially if treated prophylactically. Hence, it is prudent to reserve treatment of PDA to infants with clinically significant ductus on the basis of gestation, birth weight, serial echocardiography and clinical status to individualize the decision to treat.

Neonatologist-performed functional echocardiography in the neonatal intensive care unit

The use of point-of-care functional ultrasound to assess cardiovascular function is gaining interest in the neonatal intensive care unit (NICU). The modality has been in use in adult intensive care units for some time and has often guided management. Clinical signs such as heart rate, blood pressure, and capillary refill time, which physicians traditionally have relied upon, provide limited insight into the adequacy of systemic blood flow and organ perfusion. Enhanced cardiovascular imaging and hemodynamic evaluation offers novel insights regarding the contribution of the ductus arteriosus, myocardial performance and pulmonary hemodynamics to ongoing clinical instability. In addition, it allows more accurate delineation of the nature of the underlying disease process and facilitates the evaluation of response to therapeutic intervention. This review examines the potential clinical role of ultrasound methods in the NICU; specifically, its applications in different disease states, and how the technology may be introduced safely in the NICU.

Does point-of-care functional echocardiography enhance cardiovascular care in the NICU?

Although the last two decades have seen major advances in the care of sick, extremely premature newborns, the approach to cardiovascular assessment and monitoring remains suboptimal owing to an overreliance on poorly predictive clinical markers such as heart rate or capillary refill time. Point-of-care functional echocardiography (PCFecho) enables real-time evaluation of cardiac performance and systemic hemodynamics to characterize acute physiology, identify the exact nature of cardiovascular compromise and guide therapeutic decisions. In this article, we will review four clinical scenarios where bedside functional cardiac imaging enabled delineation of the real clinical problem and refinement of the therapeutic care plan with direct patient benefits.