Vasopressin in perioperative management of congenital diaphragmatic hernia: a case report

Perioperative care of infants with diaphragmatic hernias can be a challenge because of pulmonary hypertension and systemic hypotension. The objective of this study was to report the usefulness of vasopressin infusion in improving pulmonary and systemic haemodynamics in an infant with congenital diaphragmatic hernia. Oxygenation failure, pulmonary hypertension and refractory systemic hypotension in infants with diaphragmatic hernia are managed by ventilation and conventional inotropes (dobutamine and dopamine). Vasopressin is a recent addition that exerts vasodilatory effects on the pulmonary circulation and vasotonic effects on the systemic circulation. The net effect is a reduction in pulmonary vascular resistance and improvement in cardiac output and reduced need for inotropes. This paradoxical response (vasodilation in some vascular beds) distinguishes it from other vasoconstrictor agents. The infant was administered intravenous vasopressin infusion for severe pulmonary hypertension that needed inhaled nitric oxide and for systemic hypotension that needed multiple inotropes under close echocardiographic monitoring. Informed parental consent and appropriate institutional ethics approval were obtained. Addition of vasopressin led to improved oxygenation and weaning off from nitric therapy. Improvement in cardiac output and blood pressure facilitated the weaning off from inotropes. Close echocardiographic monitoring was performed to ascertain the haemodynamic effects of vasopressin. Under echocardiographic monitoring, vasopressin is a useful adjunct for managing pulmonary and systemic perioperative haemodynamic instability in infants with diaphragmatic hernia.Keywords: congenital diaphragmatic hernia, echocardiography, vasopressi

Genome-wide association study identifies loci and candidate genes for grain micronutrients and quality traits in wheat (Triticum aestivum L.)

Malnutrition due to micronutrients and protein deficiency is recognized among the major global health issues. Genetic biofortification of wheat is a cost-effective and sustainable strategy to mitigate the global micronutrient and protein malnutrition. Genomic regions governing grain zinc concentration (GZnC), grain iron concentration (GFeC), grain protein content (GPC), test weight (TW), and thousand kernel weight (TKW) were investigated in a set of 184 diverse bread wheat genotypes through genome-wide association study (GWAS). The GWAS panel was genotyped using Breeders' 35 K Axiom Array and phenotyped in three different environments during 2019–2020. A total of 55 marker-trait associations (MTAs) were identified representing all three sub-genomes of wheat. The highest number of MTAs were identified for GPC (23), followed by TKW (15), TW (11), GFeC (4), and GZnC (2). Further, a stable SNP was identified for TKW, and also pleiotropic regions were identified for GPC and TKW. In silico analysis revealed important putative candidate genes underlying the identified genomic regions such as F-box-like domain superfamily, Zinc finger CCCH-type proteins, Serine-threonine/tyrosine-protein kinase, Histone deacetylase domain superfamily, and SANT/Myb domain superfamily proteins, etc. The identified novel MTAs will be validated to estimate their effects in different genetic backgrounds for subsequent use in marker-assisted selection

Neonatologist performed functional echocardiography in the neonatal intensive care: clinical and research applications

Echocardiography by the neonatologist is a discipline where the frontline neonatal care giver uses ultrasound as an adjunct to their clinical acumen (extension of clinical skills).The objective is to gain further insight into disease pathophysiology so as to provide physiology driven care. There is recent data where the skill was shown to be useful and life-saving in critically sick infants. This thesis aims to address the following clinical and research applications for this discipline: a.The spread of the discipline of echocardiography by the neonatologist, clinical benefits obtained, barriers towards learning, and the need for structured training. b.Patent ductus arteriosus (PDA): how to assign haemodynamic significance and the role of ductal disease staging. c.Surgical ligation of the patent ductus arteriosus: haemodynamic issues relevant to focussed peri-operative care. d.Haemodynamic effects of common neonatal interventions such as indomethacin and surfactant. e.The effects of intrauterine growth restriction on cardiovascular function. f.The usefulness of echocardiography by the neonatologist in critically ill infants. g.Bronchopulmonary dysplasia and its effects on cardiac and vascular function. h.Role of newer imaging modalities such as speckle tracking echocardiography. The foremost issue is that of a PDA and the lack of consensus regarding whether a PDA is pathological to the extent that it should be treated very early on. Equipoise persists as to the clinical and echocardiographic significance of a PDA. Studies where treatment was based on a single echocardiographic parameter or where no stratification for the ‘severity’ of ductal disease was considered did not show significant benefit in clinical outcomes. We proposed a scoring system based on echocardiography to stratify patient population. The thesis also depicts the benefits of this discipline in understanding peri-operative haemodynamics following surgical ligation of the PDA. Surgical duct ligation is followed by a significant elevation in systemic vascular resistance, which temporally coincides with a reduction in cardiac contractility. Amongst commonly used medications, indomethacin usage was associated with a significant though transient decrease in coronary blood flow (very similar to the effect seen on mesenteric, cerebral and renal perfusion). Surfactant replacement therapy on the other hand, led to acute changes in pulmonary to systemic blood flow ratio in small preterm infants. Cardiac and vasomotor function of infants with intrauterine growth restriction has been the focus of much recent work. Cardiac function (especially diastolic function) was impaired and the data on vasomotor function showed the systemic vessel (descending aorta) to be thicker and stiffer in the early postnatal period. Bronchopulmonary dysplasia is the commonest respiratory morbidity in surviving preterm infants. The systemic (left sided) haemodynamics are not particularly well studied. We noted systemic arterial thickness and reduced ventricular contractility in this cohort. Lastly, this thesis depicts the use of newer ultrasound technology in various clinical settings. Speckle tracking echocardiography is well established in adult cardiac literature with neonatal applications beginning to emerge. We used this modality to study infants with possible acute (severe birth asphyxia) and chronic involvements (intrauterine growth restriction) of the cardiovascular system. In conclusion, this thesis covers the logistical, training and clinically relevant issues of the discipline of the neonatologist performed echocardiography. Additionally, it’s clinical and research applications are outlined with the help of already published peer-reviewed work. The clinical scenarios outlined in this work are commonly encountered in neonatal intensive care units worldwide. Some of the concepts have tremendous clinical benefits while others elucidate novel imaging technologies with exciting prospects to improve understanding of different disease states

Coronary artery perfusion and myocardial performance after patent ductus arteriosus ligation

ObjectivesTo study coronary artery (CA) perfusion and myocardial performance after patent ductus arteriosus (PDA) ligation. The postoperative course in premature infants undergoing surgical ligation of PDA is often complicated by cardiorespiratory instability secondary to impaired left ventricular performance.MethodsSerial echocardiography was performed before and after (1, 8, and 24 hours) PDA ligation to assess systolic (left ventricular output [LVO]) and diastolic (isovolumic relaxation time, E and A wave peak velocity) myocardial performance, and CA diastolic flow (CA velocity time integral and flow). The ratio of CA flow to LVO was calculated as a surrogate of coronary flow.ResultsA total of 20 infants (gestational age at birth, 26.3 ± 0.7 weeks) requiring PDA ligation at a median of 28.5 days (range, 9–40) after birth and weight of 780 g (range, 570–2840) were studied. A postoperative increase in the CA flow/LVO ratio was demonstrated. An early decrease in E and A wave peak velocity (P < .05) and increase in isovolumic relaxation time (P < .05) were demonstrated at 1 hour, before any clinical deterioration. A low baseline CA velocity time integral was associated with a low E/A ratio (r = 0.63, P = .01) at 1 hour and lower systolic blood pressure at 8 hours (r = 0.5, P = .05). The postoperative need for inotropes (n = 8) was associated with a low baseline CA velocity time integral at 1 hour (r = 0.52, P < .05), low LVO at 1 and 8 hours (P < .05), and increased oxygen requirement at 24 hours (P < .05).ConclusionsPDA ligation is followed by altered CA perfusion. Perioperative evaluation of the CA perfusion can help identify neonates at risk of impaired myocardial performance, systolic hypotension, and the need for inotropes

Vascular changes in fetal growth restriction: clinical relevance and future therapeutics

Fetal growth restriction (FGR) affects about 5–10% pregnancies and is associated with poorer outcomes in the perinatal period. Additionally, long standing epidemiological data support its association with chronic diseases such as hypertension and diabetes. Cardiac and vascular adaptations in response to chronic hypoxemia due to utero-placental insufficiency are hallmarks of fetal adaptations. Investigators have attempted to identify these changes in the placenta at the microscopic and molecular level. The ex vivo dual perfusion model of the placenta enables the study of placental haemodynamics in growth-restricted pregnancies. Persistent arterial abnormalities (thickness and stiffness) noted on vascular ultrasound during fetal life through to the young-adult age group for those affected by FGR, seem to be a plausible link between in utero events and chronic circulatory diseases. Using these, this review reflects current thought on vascular maladaptive changes in the FGR cohorts and the role in investigating current and future therapeutic

Towards rational management of the patent ductus arteriosus: the need for disease staging

Perspective on the review by Bose and Laughon (see page 498