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Sehgal A.,Monash Newborn | Sehgal A.,Monash University
European Journal of Pediatrics | Year: 2011

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. © 2011 Springer-Verlag.

Sehgal A.,Monash Newborn | Sehgal A.,Monash University
European Journal of Pediatrics | Year: 2012

Neonatal stroke is a diverse clinical entity. Terminology and aetiology described in the literature are very varied. While numerous risk factors are cited, only few case-control studies have investigated them in a systematic fashion. This equipoise extends to the investigational and management profile of perinatal stroke too. Controversy persists about the suitability of detailed haematological thrombophilia workup in the neonatal period. This case-based review details the variable clinical presentation in term and preterm neonates, discusses the current literature, ascertains the respective roles of various imaging modalities, explores relevant new neuroprotective interventions and proposes a systematic approach to clinical and neuroimaging workup. Long-term follow-up is important as many infants suffer neuro-disability, which might need early intervention strategies. © 2011 Springer-Verlag.

Sasi A.,Monash Newborn | Sehgal A.,Monash Newborn | Sehgal A.,Monash University
Heart and Lung: Journal of Acute and Critical Care | Year: 2014

Objectives: To conduct a regional survey of neonatal intensive care unit (NICU) Directors in Australia and New Zealand (ANZ) to ascertain current practice. Background: Use of inhaled nitric oxide (iNO) therapy in infants<34 weeks gestational age is not supported by current evidence. Methods: A cross-sectional electronic survey based on structured questionnaire was conducted amongst the Directors of all the tertiary neonatal intensive care units in Australia and New Zealand Neonatal Network (ANZNN). Information was collected on indications, dosage, monitoring response and weaning for iNO therapy. Results: The survey was sent to 28 units, of which 2 were quaternary units' not routinely admitting preterm infants, hence were excluded from analysis. The response rate was 77% (20/26). Majority of units (16; 80%) did not have preterm specific protocol. In almost all units nitric was used as early rescue for hypoxemic respiratory failure (95%; 19/20). Neonatologist performed functional echocardiography (fECHO) was frequently used for prior assessment (90%) and monitoring (65%). Variations were noted regarding initiating criteria, dosage and weaning strategies. Conclusions: Wide variation in practice was noted highlighting the need for the formulation of consensus guidelines. © 2014 Elsevier Inc.

Sehgal A.,Monash Newborn | Sehgal A.,Monash University | Doctor T.,Monash Newborn | Menahem S.,Pediatric Cardiology
Pediatric Cardiology | Year: 2014

Existing data suggest subendocardial ischemia in preterm infants with patent ductus arteriosus (PDA) and alterations in cardiac function after indomethacin administration. This study aimed to explore the evolution of left ventricular function by conventional echocardiography and speckle-tracking echocardiography (STE) and to ascertain the interrelationship with coronary flow indices in response to indomethacin. A prospective observational study was performed with preterm infants receiving indomethacin for medical closure of PDA. Serial echocardiography was performed, and the results were analyzed using analysis of variance. Intra- and interobserver variability was assessed using the intraclass correlation coefficient. Indomethacin was administered to 18 infants born at a median gestational age of 25.8 weeks (interquartile range [IQR], 24.2–28.1 weeks) with a birth weight of 773 g (IQR, 704–1,002 g). The median age of the infants was 7.5 days (IQR, 4–17). Global longitudinal strain (GLS) values significantly decreased immediately after indomethacin infusion (preindomethacin GLS, −19.1 ± 2.4 % vs. −15.9 ± 1.7 %; p < 0.0001) but had improved at reassessment after 1 h (−17.4 ± 1.8 %). Conventional echocardiographic indices did not show significant alterations. A significant increase in arterial resistance in the coronary vasculature from 1.7 to 2.4 mmHg/cm/s was demonstrated. A significant correlation was noted between peak systolic GLS and flow resistance in the coronary vasculature. Significant changes in myocardial indices were observed immediately after indomethacin infusion. Compared with conventional methods, STE is a more sensitive tool to facilitate understanding of hemodynamics in preterm infants. © 2014, Springer Science+Business Media New York.

Sehgal A.,Monash Newborn | Sehgal A.,Monash University | Doctor T.,Monash Newborn | Menahem S.,Monash University
Acta Paediatrica, International Journal of Paediatrics | Year: 2014

Aim To compare strain indices between small for gestational age (SGA) infants and asymptomatic appropriate for gestational age (AGA) infants and to ascertain correlations with arterial biophysical properties. Methods In this prospective observational echocardiographic study, 20 inborn term SGA infants weighing <3rd centile for gestational age were compared with 20 AGA infants. Demographic and echocardiographic data were analysed regarding cardiac strain and strain rate and arterial indices (stiffness, impedance and strain elastic modulus). Correlations between variables were assessed using Pearson's coefficient of correlation. Results Ponderal index was significantly lower in SGA infants (24.6 ± 2.9 vs. 29.5 ± 2.5). Left ventricular global longitudinal strain (GLS) was noted to be significantly impaired in the SGA infants (-15.9% ± 2.1 vs. -21.3% ± 2.8, p < 0.001). A basal to apical gradient was noted in segmental strain. Arterial biophysical measurements were significantly altered in the SGA infants. Significant correlations were noted between GLS and arterial stiffness (r = -0.4, p = 0.03), weight-indexed stiffness (r = -0.45, p = 0.02) and pressure-strain elastic modulus (r = -0.49, p = 0.01). Conclusion Impairment in myocardial deformation was noted in the presence of altered arterial biophysical properties in the SGA infants. © 2013 Foundation Acta Pædiatrica. Published by John Wiley & Sons Ltd.

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