ORCID Profile
0000-0002-1413-2966
Current Organisations
Sinai Health System
,
Lunenfeld-Tanenbaum Research Institute
,
University of Toronto
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Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.JTCVS.2016.03.085
Abstract: The postoperative course of preterm babies undergoing surgical closure of a patent ductus arteriosus (PDA) is often complicated by postligation cardiac syndrome (PLCS). Despite targeted milrinone prophylaxis, some infants continue to experience postoperative respiratory deterioration. Our objective is to describe the immediate postoperative course and identify risk factors for respiratory instability when preterm infants undergoing PDA ligation are managed with targeted milrinone treatment. A retrospective review of a cohort of infants undergoing PDA ligation between January, 2010 and August, 2013 was conducted. All infants had a targeted neonatal echocardiogram performed 1 hour after surgery. Infants received prophylactic milrinone treatment if the left ventricular output was <200 mL/kg/min. The primary outcome measure was the development of respiratory instability within 24 hours of surgery. Multivariable logistic regression was performed to identify predictors of respiratory instability. Eighty-six infants with a median gestational age of 25 weeks (interquartile range [IQR], 24-26) and a birth weight of 740 g (IQR, 640-853) were included in this study. Forty-nine (57.0%) received milrinone prophylaxis. There were 44 (51.2%) infants who developed oxygenation or ventilation failure, and 7 (8.1%) neonates developed PLCS. Infants with longer isovolumic relaxation time (IVRT ≥30 milliseconds) were more likely to develop either oxygenation or ventilation failure. Although the incidence of PLCS has declined after the introduction of targeted milrinone prophylaxis, many preterm infants continue to develop respiratory instability after surgical ligation. In this population, diastolic dysfunction manifested by prolonged IVRT could be associated with an adverse postoperative respiratory course.
Publisher: Springer Science and Business Media LLC
Date: 18-06-2014
DOI: 10.1038/PR.2014.82
Publisher: Springer Science and Business Media LLC
Date: 04-10-2017
DOI: 10.1038/PR.2017.200
Abstract: It is increasingly recognized that the abnormal physiologic consequences of pulmonary hypertension (PH) may contribute to poor cardiopulmonary health in premature babies. Conflicting literature has led to clinical uncertainty, pathological misinterpretation, and variability in treatment approaches among practitioners. There are several disorders with overlapping and interrelated presentations, and other disorders with a similar clinical phenotype but erse pathophysiological contributors. In this review, we provide a diagnostic approach for acute hypoxemic respiratory failure in the preterm neonate, outline the pathophysiological conditions that may present as acute PH, and discuss the implications of high pulmonary vascular resistance (PVR) on the cardiovascular system. Although PVR and respiratory management are highly interrelated, there may be a population of preterm neonates in whom inhaled nitric oxide may improve illness severity and may relate to outcomes. A management approach based on physiology that considers common clinical conundrums is provided. A more comprehensive understanding of the physiology may help in informed decision-making in clinical situations where conclusive scientific evidence is lacking. Regardless, high-quality research is required, and appropriate definition of the target population is paramount. A thoughtful approach to cardiovascular therapy may also provide an avenue to improve neurodevelopmental outcomes while awaiting more clear answers.
Publisher: Springer Science and Business Media LLC
Date: 14-01-2016
DOI: 10.1038/JP.2015.213
Abstract: The decision to perform patent ductus arteriosus (PDA) ligation is controversial. Patient selection is oftentimes poorly standardized, leading to delays in referral and inappropriate intervention. A system for PDA ligation categorization and triaging process was introduced in 2006 at a quaternary hospital in Canada to streamline referrals and enhance perioperative care. We aimed to evaluate the impact of this dedicated PDA ligation triaging system comparing pre- and postimplementation of this system. We performed a retrospective chart review. Demographic and cardiorespiratory data of neonates ⩽30 weeks gestation age at birth, who were referred for and/or had a PDA ligation performed during two distinct epochs (EPOCH 1 (2003 to 2005) and EPOCH 2 (2010 to 2012)), were analyzed. All surgeries were performed at The Hospital for Sick Children, the regional referral center for PDA ligation. The primary outcome was incidence of PDA ligation and procedural cancellations. Secondary outcomes included postoperative need for cardiovascular or respiratory support. Subgroup analysis was performed in neonates 1000 g at the time of surgery during both epochs. A total of 198 neonates underwent surgery with no difference in baseline demographics between epochs. The incidence of PDA ligation as a proportion of total live births under 30 weeks in Central East Region of Ontario was lower in the second epoch (EPOCH 1: 117/1092 (10.7%) vs EPOCH 2: 81/1520 (5.3%)). During the second epoch, 24% of referrals for surgery were canceled after review by our PDA ligation team. There were no overall differences in the proportion of neonates with oxygenation failure, ventilation failure or Post-Ligation Cardiac Syndrome (PLCS), after surgery, between epochs. The proportion of neonates who developed systemic hypotension was higher in patients <1000 g (n=34 (34%) vs n=17 (17.4%), P=0.01) at the time of surgery. In addition, we identified a reduction in the proportion of neonates 1000 g who developed ventilation failure in EPOCH 2. The presence of dedicated triaging and management system enhances efficiency of referral process through careful selection of patients for PDA ligation and optimizes perioperative management. We demonstrated a reduction in the incidence of PDA ligation without any negative impact on short-term neonatal morbidity. The use of targeted neonatal echocardiography in the assessment of PDA shunt volume and guiding postoperative decision making is likely to have contributed to these findings.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.PEDNEO.2019.04.003
Abstract: Hypoxic-ischemic encephalopathy (HIE) is associated with disturbances in visceral blood flow velocities. Therapeutic Hypothermia (TH) is a standard of care however, its impact on gastrointestinal blood flow in infants with HIE is unknown. The objective of this study was to assess gastrointestinal (GI) blood flow and left ventricle output (LVO) in infants with hypoxic-ischemic encephalopathy during whole body TH and after rewarming. Serial echocardiography and Doppler evaluation of intestinal blood flow (celiac (CA) and superior mesenteric (SMA) arteries) were prospectively performed in a cohort of 20 newborn infants with HIE at 4 time points during hypothermia and after rewarming. Demographic, clinical and biochemical data were collected and analyzed for their relevance. Median gestational age and birth weight was 40 weeks (37-41) and 3410 g (2190-4950) respectively. Celiac and mesenteric artery flow remained low during hypothermia and rose significantly after rewarming [peak systolic velocity in CA (0.63 m/s to 0.77 m/s, p = 0.004) and SMA (0.43 m/s to 0.55 m/s, p = 0.001)]. This increase was temporally associated with increased left ventricular output (106 ml/kg/min to 149 ml/kg/min, p < 0.0001). Median age to reach 25% of the feeds was 5 days (1-7 days). All patients survived. CA and SMA blood flow velocity and LVO did not vary during hypothermia but rose after rewarming. This may suggest protective effect of therapeutic hypothermia on gastrointestinal system. The association of these physiological changes with neonatal outcome needs further assessment.
Publisher: Georg Thieme Verlag KG
Date: 23-02-2018
Abstract: Objective This article compares hemodynamic characteristics of neonates with hypoxic ischemic encephalopathy (HIE) receiving therapeutic hypothermia (TH) with normal versus abnormal brain magnetic resonance imaging (MRI). Methods Serial echocardiography (echo) was performed within 24 hours, after 48 to 72 hours of cooling, within 24 hours of normothermia, and after starting feeds. Pulmonary hemodynamics, cardiac output, and ventricular function were evaluated. All neonates underwent brain MRI (day 4–5), per clinical standard of care. Clinical cardiovascular and echocardiography characteristics were compared between patients with normal versus abnormal MRI. Cardiovascular changes during TH and after rewarming were identified. Results Twenty neonates at median gestation and birth weight of 40 weeks (interquartile range [IQR]: 39, 41) and 3,410 g (IQR: 2,885, 4,093), respectively, were enrolled. Increased median left ventricular output (LVO) (106–159 mL/kg/min, p 0.001) and reduced isovolumic relaxation time (IVRT) (48–42 ms, p 0.001) were seen after rewarming. Echocardiography evidence of pulmonary hypertension (PH) was identified in five neonates. Eight neonates (40%) had brain injury identified on MRI (watershed [n = 4], basal ganglia [n = 4]) this subgroup were more likely to have echo evidence of PH at 24 hours. Conclusion Longitudinal changes in cardiac output were noted in neonates with HIE during TH and rewarming. Echocardiography evidence of PH, however, was associated with abnormal MRI brain. The prognostic relevance of these physiologic changes requires more comprehensive delineation.
Publisher: Elsevier BV
Date: 06-2014
Publisher: Springer Science and Business Media LLC
Date: 14-08-2014
DOI: 10.1038/JP.2014.151
No related grants have been discovered for Amish Jain.