Hemodynamic instability in the critically ill neonate: An approach to cardiovascular support based on disease pathophysiology

Cardiac Development and Related Clinical Considerations

The anatomy, physiology, and hemodynamics of the premature heart vary along the range of gestational ages cared for in neonatal intensive care units, from 22 weeks to term gestation. Clinical management of the preterm neonate should account for this heterogenous development. This requires an understanding of the impact of ex utero stressors on immature and disorganized cardiac tissue, the different state of hemodynamics across intracardiac shunts impacting the natural transition from fetal to neonatal life, and the effects of intensive pharmacologic and non-pharmacologic interventions that have systemic consequences influencing cardiac function. This article provides a review of the increasing but still limited body of literature on the anatomy, hemodynamics, and electrophysiology of the preterm heart with relevant clinical considerations.

Educational Impact of Targeted Neonatal Echocardiography and Hemodynamics Programs on Neonatal-Perinatal Medicine Fellows

OBJECTIVE

Targeted neonatal echocardiography (TNE) is a real-time cardiac imaging modality used by a hemodynamics program to aid in diagnosis, treatment, and monitoring of neonatal cardiovascular illness. This study aimed to describe trainees' perspectives on existing hemodynamics education and perceived impacts of TNE and hemodynamics services on their education.

STUDY DESIGN

This was a mixed quantitative and qualitative study that surveyed neonatal-perinatal medicine (NPM) fellow trainees in Canada and the United States, at programs both with and without a hemodynamics service.

RESULTS

Ninety-two fellows responded to the survey, of whom 24 (26%) were enrolled in a program with an active hemodynamics service, 64 (70%) were training at a program without a hemodynamics service, and 4 (4%) were unsure. Trainees at centers with a hemodynamics service were more satisfied with their cardiovascular physiology education (91 vs. 69%, p = 0.040). Twenty-five percent of all trainees felt they do not have sufficient hemodynamics training to prepare them for independent practice. Areas of knowledge gaps were identified. Bedside teaching combined with didactic teaching was identified as useful means of teaching.

CONCLUSION

Most trainees believed that TNE and a hemodynamics service are valuable educational assets. Thoughtful curriculum design for real-time and consolidation learning, with specific emphasis on content gaps, should be considered.

KEY POINTS

· NPM Fellows perceive TNE & Neonatal Hemodynamics service as a valuable educational opportunity.. · Incorporation of TNE/Hemodynamics teaching into NPM curriculum can enrich trainee experience.. · Combining bedside and classroom teaching is key to successful cardiovascular training..

An Update on Pharmacologic Management of Neonatal Hypotension: When, Why, and Which Medication

Anti-hypotensive treatment, which includes dopamine, dobutamine, epinephrine, norepinephrine, milrinone, vasopressin, terlipressin, levosimendan, and glucocorticoids, is a long-established intervention in neonates with arterial hypotension (AH). However, there are still gaps in knowledge and issues that need clarification. The main questions and challenges that neonatologists face relate to the reference ranges of arterial blood pressure in presumably healthy neonates in relation to gestational and postnatal age; the arterial blood pressure level that potentially affects perfusion of critical organs; the incorporation of targeted echocardiography and near-infrared spectroscopy for assessing heart function and cerebral perfusion in clinical practice; the indication, timing, and choice of medication for each individual patient; the limited randomized clinical trials in neonates with sometimes conflicting results; and the sparse data regarding the potential effect of early hypotension or anti-hypotensive medications on long-term neurodevelopment. In this review, after a short review of AH definitions used in neonates and existing data on pathophysiology of AH, we discuss currently available data on pharmacokinetic and hemodynamic effects, as well as the effectiveness and safety of anti-hypotensive medications in neonates. In addition, data on the comparisons between anti-hypotensive medications and current suggestions for the main indications of each medication are discussed.

Diagnosis and management of congenital diaphragmatic hernia: a 2023 update from the Canadian Congenital Diaphragmatic Hernia Collaborative

OBJECTIVE

The Canadian Congenital Diaphragmatic Hernia (CDH) Collaborative sought to make its existing clinical practice guideline, published in 2018, into a 'living document'.

DESIGN AND MAIN OUTCOME MEASURES

Critical appraisal of CDH literature adhering to Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Evidence accumulated between 1 January 2017 and 30 August 2022 was analysed to inform changes to existing or the development of new CDH care recommendations. Strength of consensus was also determined using a modified Delphi process among national experts in the field.

RESULTS

Of the 3868 articles retrieved in our search that covered the 15 areas of CDH care, 459 underwent full-text review. Ultimately, 103 articles were used to inform 20 changes to existing recommendations, which included aspects related to prenatal diagnosis, echocardiographic evaluation, pulmonary hypertension management, surgical readiness criteria, the type of surgical repair and long-term health surveillance. Fifteen new CDH care recommendations were also created using this evidence, with most related to the management of pain and the provision of analgesia and neuromuscular blockade for patients with CDH.

CONCLUSIONS

The 2023 Canadian CDH Collaborative's clinical practice guideline update provides a management framework for infants and children with CDH based on the best available evidence and expert consensus.

Global longitudinal strain is an informative index of left ventricular performance in neonates receiving intensive care

Echocardiographic assessment of left ventricular function is crucial in NICU. The study aimed to compare the accuracy and agreement of global longitudinal strain (GLS) with conventional measurements. Real-life echocardiograms of neonates receiving intensive care were retrospectively reviewed. Shortening fraction (SF), ejection fraction (EF) and S' measurements were retrieved from health records. GLS was calculated offline from stored images. The association with stroke volume indexed for body weight (iSV) was evaluated by regression analysis. The diagnostic ability to identify uncompensated shock was assessed by ROC curve analysis. Cohen's κ was run to assess agreement. 334 echocardiograms of 155 neonates were evaluated. Mean ± SD gestational age and birth weight were 34.5 ± 4.1 weeks and 2264 ± 914 g, respectively. SF, EF, S' and GLS were associated with iSV with R2 of 0.133, 0.332, 0.252 and 0.633, (all p < .001). Including all variables in a regression model, iSV prediction showed an adjusted R2 of 0.667, (p < .001). GLS explained 73% of the model variance. GLS showed a better ability to diagnose uncompensated shock (AUC 0.956) compared to EF, S' and SF (AUC 0.757, 0.737 and 0.606, respectively). GLS showed a moderate agreement with EF (κ = .500, p < .001) and a limited agreement with S' and SF (κ = .260, p < .001, κ = .242, p < .001). GLS was a more informative index of left ventricular performance, providing the rationale for a more extensive use of GLS at the cotside.

Tissue-Tracking Mitral Annular Displacement in Neonates: A Novel Index of Left Ventricular Systolic Function

OBJECTIVES

To assess the feasibility, accuracy, and reproducibility of tissue-tracking mitral annular displacement (TMAD) compared with other measures of left ventricular systolic function in healthy preterm and term neonates in the transitional period.

METHODS

This was a prospective observational study. Two echocardiograms were performed at 24 and 48 hours of life. TMAD, shortening fraction (SF), ejection fraction (EF), s', and global longitudinal strain (GLS) were measured offline. Accuracy to detect impaired GLS was tested by ROC curve analysis. DeLong test was used to compare AUCs. Intra and interobserver reproducibility of the off-line analysis was calculated.

RESULTS

Mean ± SD gestational age and weight were 34.2 ± 3.8 weeks and 2162 ± 833 g, respectively. TMAD was feasible in 168/180 scans (93%). At 24 hours the AUC (95% CI) of SF, EF, s', and TMAD (%) was 0.51 (0.36-0.67), 0.68 (0.54-0.82), 0.63 (0.49-0.77), and 0.89 (0.79-0.99) respectively. At 48 hours the AUC (95% CI) of SF, EF, s', and TMAD (%) was 0.64 (0.51-0.77), 0.59 (0.37-0.80), 0.70 (0.54-0.86), and 0.96 (0.91-1.00), respectively. The AUC of TMAD was superior to the AUC of SF, EF, s', at both timepoints (P < .02). Intraclass correlation coefficients (95% CI) of intra and interobserver reproducibility of TMAD were 0.97 (0.95-0.99) and 0.94 (0.88-0.97), respectively.

CONCLUSION

TMAD showed improved accuracy and optimal reproducibility in neonates in the first 48 hours of life.

Impact of persistent pulmonary hypertension and oxygenation on brain injury in neonates with neonatal encephalopathy treated with therapeutic hypothermia

OBJECTIVE

To investigate the effects of persistent pulmonary hypertension (PPHN) and oxygenation on outcome of neonates with neonatal encephalopathy (NE) treated with therapeutic hypothermia (TH).

STUDY DESIGN

We compared the outcome of neonates with NE treated with TH with or without PPHN.

RESULTS

384 neonates with NE were treated with TH; 24% had PPHN. The fraction of inspired oxygen was higher in the first 4 days of life (p < 0.001) in neonates with PPHN. They had a significantly lower arterial partial pressure of oxygen in the first 4 days of life (p = 0.005) and higher on days 3-4 of life (p < 0.001). They were more often intubated (p < 0.001) and more often had concomitant hypotension (p < 0.001). They had higher mortality (p = 0.009) and more often developed brain injury (p = 0.02).

CONCLUSION

PPHN occurred frequently in neonates with NE treated with TH and was associated with a higher incidence of adverse outcome.

Critical illness-related corticosteroid insufficiency (CIRCI) in paediatric patients: a diagnostic and therapeutic challenge

Critical illness-related corticosteroid insufficiency or CIRCI is characterized by acute and life-threatening disfunction of hypothalamic-pituitary-adrenal (HPA) axis observed among intensive care unit- staying patients.It is associated with increased circulating levels of biological markers of inflammation and coagulation, morbidity, length of ICU stay, and mortality.Several mechanisms are involved in CIRCI pathogenesis: reduced CRH-stimulated ACTH release, peripheral resistance to glucocorticoids, altered cortisol synthesis, impaired cortisol-free fraction and bioavailability.Diagnostic and therapeutic management of this condition in children is still debated, probably because of the lack of agreement among intensive care specialists and endocrinologists regarding diagnostic criteria and prevalence of CIRCI in paediatric age.In the present narrative review, we focused on definition of CIRCI in paediatric age and we advise on how to diagnose and treat this poorly understood condition, based on current literature data.

Inhaled Nitric Oxide in Neonatal Pulmonary Hypertension

Pivotal trials investigating the use of inhaled nitric oxide (iNO) in the 1990s led to approval by the Food and Drug Administration in 1999. Inhaled nitric oxide is the only approved pulmonary vasodilator for persistent pulmonary hypertension of the newborn (PPHN). Selective pulmonary vasodilation with iNO in near-term and term neonates with PPHN is safe, and targeted use of iNO in less mature neonates with pulmonary hypertension (PH) can be beneficial. This review addresses a brief history of iNO, clinical features of neonatal PH, and the clinical application of iNO.

Arch watch: current approaches and opportunities for improvement

Coarctation of the aorta (CoA) is a ductus arteriosus (DA)-dependent form of congenital heart disease (CHD) characterized by narrowing in the region of the aortic isthmus. CoA is a challenging diagnosis to make prenatally and is the critical cardiac lesion most likely to go undetected on the pulse oximetry-based newborn critical CHD screen. When undetected CoA causes obstruction to blood flow, life-threatening cardiovascular collapse may result, with a high burden of morbidity and mortality. Hemodynamic monitoring practices during DA closure (known as an "arch watch") vary across institutions and existing tools are often insensitive to developing arch obstruction. Novel measures of tissue oxygenation and oxygen deprivation may improve sensitivity and specificity for identifying evolving hemodynamic compromise in the newborn with CoA. We explore the benefits and limitations of existing and new tools to monitor the physiological changes of the aorta as the DA closes in infants at risk of CoA.

Understanding Near-Infrared Spectroscopy: An Update

Near-infrared spectroscopy (NIRS) is a novel technology that uses infrared light to noninvasively and continuously measure regional oxygen extraction in real time at the bedside. Neonatal research using this device supports its use as an adjunct to routine cardiovascular monitoring because NIRS serves as a surrogate marker for end-organ perfusion and can detect minute changes in cerebral, intestinal, and kidney tissue beds. Multiple conditions affecting premature infants are frequently associated with hypoperfusion; therefore, methods to detect early tissue-specific perfusion alterations may substantially improve the clinician's ability to intervene and prevent further deterioration.

The impact of a care bundle with an emphasis on hemodynamic assessment on the short-term outcomes in neonates with congenital diaphragmatic hernia

OBJECTIVE

To evaluate the short-term outcomes of implementing a care bundle emphasizing frequent hemodynamic assessments by echocardiography in neonates with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This was a retrospective cohort study of infants with CDH admitted to a quaternary perinatal unit from January 2013 to March 2021. The primary composite outcome was defined as mortality or use of extracorporeal membrane oxygenation or need for respiratory support at discharge.

RESULTS

We identified 37 and 20 CDH infants in Epoch I and II, respectively. More patch repairs (50% vs. 21.9%, p = 0.035) and echocardiograms (6[4-8] vs. 1[0-5], p = 0.003) were performed in Epoch II. While there were no differences in the primary outcome, there was a reduction in mortality in Epoch II (0% vs. 27%, p = 0.01).

CONCLUSION

With the implementation of a CDH care bundle with an emphasis on hemodynamic assessment, we demonstrated a significant reduction in mortality.

Predicting the effectiveness of drugs used for treating cardiovascular conditions in newborn infants

BACKGROUND

Cardiovascular support (CVS) treatment failure (TF) is associated with a poor prognosis in preterm infants.

METHODS

Medical charts of infants with a birth weight <1500 g who received either dopamine (Dp) or dobutamine (Db), were reviewed. Treatment response (TR) occurred if blood pressure increased >3rd centile for gestational age or superior vena cava flow was maintained >55 ml/kg/min, with decreased lactate or less negative base excess, without additional CVS. A predictive model of Dp and Db on TR was designed and the impact of TR on survival was analyzed.

RESULTS

Sixty-six infants (median gestational age 27.3 weeks, median birth weight 864 g) received Dp (n = 44) or Db (n = 22). TR occurred in 59% of the cases treated with Dp and 31% with Db, p = 0.04. Machine learning identified a model that correctly labeled Db response in 90% of the cases and Dp response in 61.4%. Sixteen infants died (9% of the TR group, 39% of the TF group; p = 0.004). Brain or gut morbidity-free survival was observed in 52% vs 30% in the TR and TF groups, respectively (p = 0.08).

CONCLUSIONS

New predictive models can anticipate Db but not Dp effectiveness in preterm infants. These algorithms may help the clinicians in the decision-making process.

IMPACT

Failure of cardiovascular support treatment increases the risk of mortality in very low birth weight infants. A predictive model built with machine learning techniques can help anticipate treatment response to dobutamine with high accuracy. Predictive models based on artificial intelligence may guide the clinicians in the decision-making process.

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.

Strong Association between Inotrope Administration and Intraventricular Hemorrhage, Gestational Age, and the Use of Fentanyl in Very Low Gestational Age Infants: A Retrospective Study

This was a single center, retrospective cohort study designed to evaluate the association between the administration of inotropes to hypotensive very low gestational age infants (VLGAI) and prenatal and neonatal risk factors. Inpatient medical records were reviewed to identify neonates treated with inotropes (treated group) and a control group for comparison. Two hundred and twenty two (222) VLGAI (less than 32 weeks' gestation) were included in the final analysis and were stratified based on timing of treatment with 83 infants (37.4%) and 139 infants (62.6%) in the treated and control groups, respectively. A total of 56/83 (67%) received inotropes for arterial hypotension during the first 3 days (early treatment subgroup) and 27/83 (32.5%) after 3 days of life (late-treated subgroup). Fentanyl, severe intraventricular hemorrhage (IVH), and gestational age (GA) were the risk factors most significantly associated with the need for inotrope use both during the first 3 days of life and the whole NICU stay, before and after adjustment for confounders. In conclusion, fentanyl, severe IVH, and GA are the risk factors most strongly associated with the need for inotrope treatment in VLGAI. Measures to modify these risk factors may decrease the need for cardiovascular medications and improve outcomes.

Evidence-Based Guidelines for Acute Stabilization and Management of Neonates with Persistent Pulmonary Hypertension of the Newborn

Persistent pulmonary hypertension of the newborn, or PPHN, represents a challenging condition associated with high morbidity and mortality. Management is complicated by complex pathophysiology and limited neonatal specific evidence-based literature, leading to a lack of universal contemporary clinical guidelines for the care of these patients. To address this need and to provide consistent high-quality clinical care for this challenging population in our neonatal intensive care unit, we sought to develop a comprehensive clinical guideline for the acute stabilization and management of neonates with PPHN. Utilizing cross-disciplinary expertise and incorporating an extensive literature search to guide best practice, we present an approachable, pragmatic, and clinically relevant guide for the bedside management of acute PPHN. KEY POINTS: · PPHN is associated with several unique diagnoses; the associated pathophysiology is different for each unique diagnosis.. · PPHN is a challenging, dynamic, and labile process for which optimal care requires frequent reassessment.. · Key management goals are adequate tissue oxygen delivery, avoiding harm..

Relationship between cerebral oxygenation, cardiac output, and blood pressure during transitional period in extremely low gestational age neonates

Objective

To describe the relationship between cerebral oxygenation, cardiac output, arterial blood pressure (BP), and cerebral blood flow velocity in extremely low gestational age neonates (ELGANs) during transition.

Methods

This study comprises secondary analyses from a prospective observational study conducted at a tertiary Neonatal Intensive Care Unit. Recruited ELGANs underwent cerebral saturation (CrSO2) monitoring and serial echocardiography during 72 h from birth. Correlative analyses of CrSO2 and cerebral fractional tissue oxygen extraction (CFTOE) with left (LVO) and right ventricular output (RVO), superior vena cava (SVC) flow, middle cerebral artery blood flow mean velocity (MCA.MV), systolic (SBP), diastolic (DBP), and mean (MBP) BP were conducted.

Results

Fifty ELGANs with median (range) gestational age of 25.9 (23.1-27.9) weeks were recruited. Echocardiography was performed sequentially at a median (range) age 5.0 (3.8-6.6), 17.3 (15.4-19.4), 31.0 (27.0-34.1), and 53.7 (49.3-58.3) hours. RVO, LVO, CrSO2, and SBP increased over time but no changes in MBP, DBP, CFTOE, MCA.MV or SVC flow were noted. A weak correlation was identified between CrSO2 and SBP (r2 = 0.11, p = 0.047) and MBP (r2 = 0.12, p = 0.04) at 17.3 (15.4-19.4) hours. No correlation of either CrSO2 or CFTOE with any measures of blood flow was identified.

Conclusion

There is a weak correlation between measures of cardiac output, BP, and MCA.MV with both CrSO2 and CFTOE in ELGANs during transition. Whether this finding suggests intact cerebral autoregulation requires prospective evaluation in a cohort of sick ELGANs.

Assessment and management of neonates with unrepaired congenital heart disease

PURPOSE OF REVIEW

To review preoperative assessment and management of neonates with congenital heart disease (CHD).

RECENT FINDINGS

The spectrum for neonates with CHD can be wide and complex. An in-depth understanding of their physiology is the first step in assessing their hemodynamics and developing an effective therapeutic strategy.

SUMMARY

There is significant heterogeneity in the anatomy and physiology in newborns with CHD. Their complex pathophysiology can be simplified into seven basic subtypes, which include systolic dysfunction, diastolic dysfunction, excessive pulmonary blood flow, obstructed pulmonary blood flow, obstructed systemic blood flow, transposition physiology, and single ventricle physiology. It is important to note these physiologies are not mutually exclusive, and this review summarizes the hemodynamic and therapeutic strategies available for the preoperative neonate with CHD.

A study protocol for investigating the sonographic characteristics of neonates with critical illness: an observational cohort study

BACKGROUND

Haemodynamic instability and hypoxaemia are common and serious threats to the survival of neonates. A growing body of literature indicates that critical care ultrasound has become the optimal evaluation tool for sick neonates. However, few studies have described sonographic characteristics of haemodynamics systematically in the neonates with critical illness. This protocol describes a prospective observational cohort study aimed at (1) characterising the sonographic characteristics of the neonates with critical diseases; and (2) assessing the mortality, significant morbidity, utility of vasoactive medications, fluid resuscitation, duration of ventilation, etc. METHODS AND ANALYSIS: This is a single-centre, prospective and observational study conducted in Chengdu Women's and Children's Central Hospital from 1 December 2022 to 31 December 2027. Neonates admitted to the neonatal intensive care unit will be recruited. After inclusion, the neonates will undergo the neonatal critical care ultrasound. The data collected via case report forms include clinical variables and sonographic measures. The primary outcome is to identify the sonographic characteristics of sick neonates with different diseases, and the secondary outcome is to describe the mortality, significant morbidity, utility of vasoactive medications, fluid resuscitation and duration of ventilation.

DISCUSSION

Our study provided an organised neonatal critical care ultrasound workflow, which can be applied in practice. Accordingly, this study will first set up large data on the sonographic description of the neonates with critical illness, which can help to understand the pathophysiology of the critical illness, potentially titrating the treatment.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2200065581; https://www.chictr.org.cn/com/25/showproj.aspx?proj=184095).

Echocardiography-directed management of hemodynamically unstable neonates in tertiary care hospitals

Background

Hemodynamic instability and inadequate cardiac performance are common in critically ill children. The clinical assessment of hemodynamic status is reliant upon physical examination supported by clinical signs such as heart rate, blood pressure, capillary refill time, and measurement of urine output and serum lactate. Unfortunately, all of these parameters are surrogate markers of cardiovascular well-being, and they provide limited direct information regarding the adequacy of blood flow and tissue perfusion. A bedside point-of-care echocardiography can provide real-time hemodynamic information by assessing cardiac function, loading conditions (preload and afterload), and cardiac output, which makes it an ideal tool for monitoring hemodynamic assessment in neonates and children.

Methods

A prospective cross-section study was carried out on all neonates admitted to the NICU of Cairo University Children’s Hospital (CUCH) during the period from September 2017 through August 2018 in whom manifestations of hemodynamic instability were elected regardless of gestational age, weight, gender, or type of disease.

Results

There is a positive correlation between EF, FS, LVOT, RVOT, LVTI, RVTI, MAPSE, and TAPSE with birth weight. There is a negative correlation between birth weight and either LVO or RVO. In neonates weighted > 1500 g, there is a significant correlation between decreases in longitudinal systolic function of the heart (TAPSE and MAPSE) and either hemodynamic instability or need for echo-directed management, but there is no significant correlation between both in neonates weighted ≤ 1500 g. There is a significant relationship between birth weight and survival “the more the births weight the better survival chance and between complete compliance with ECDM protocol and achieving normal hemodynamic state.”

Conclusions

Decreases in EF, FS, TAPSE, and MAPSE in low birth weight neonates’ ≤ 1500 g are late signs of hemodynamic instability. TAPSE and MAPSE are the earliest parameters noticed to be decreased in hemodynamically unstable neonates > 1500 g even before EF and FS but return to normal values latterly. There is a significant relationship between complete compliance with ECDM protocol and achieving normal hemodynamics. Birth weight of ≤ 1500 g was an independent predictor of mortality regardless of the degree of compliance with the protocol.

Delayed Surgical Closure of the Patent Ductus Arteriosus: Does the Brain Pay the Price?

OBJECTIVE

To investigate the relation between duration of hemodynamically significant patent ductus arteriosus (PDA), cerebral oxygenation, magnetic resonance imaging-determined brain growth, and 2-year neurodevelopmental outcome in a cohort of infants born preterm whose duct was closed surgically.

STUDY DESIGN

Infants born preterm at <30 weeks of gestational age who underwent surgical ductal closure between 2008 and 2018 (n = 106) were included in this observational study. Near infrared spectroscopy-monitored cerebral oxygen saturation during and up to 24 hours after ductal closure and a Bayley III developmental test at the corrected age of 2 years is the institutional standard of care for this patient group. Infants also had magnetic resonance imaging at term-equivalent age.

RESULTS

In total, 90 infants fulfilled the inclusion criteria (median [range]: 25.9 weeks [24.0-28.9]; 856 g [540-1350]. Days of a PDA ranged from 1 to 41. Multivariable linear regression analysis showed that duration of a PDA negatively influenced cerebellar growth and motor and cognitive outcome at 2 years of corrected age.

CONCLUSIONS

Prolonged duration of a PDA in this surgical cohort is associated with reduced cerebellar growth and suboptimal neurodevelopmental outcome.

Magnetic resonance venography to evaluate cerebral sinovenous thrombosis in infants receiving therapeutic hypothermia

BACKGROUND

The incidence of cerebral sinovenous thrombosis (CSVT) in infants receiving therapeutic hypothermia for neonatal encephalopathy remains controversial. The aim of this study was to identify if the routine use of magnetic resonance venography (MRV) in term-born infants receiving hypothermia is associated with diagnostic identification of CSVT.

METHODS

We performed a retrospective review of 291 infants who received therapeutic hypothermia from January 2014 to March 2020. Demographic and clinical data, as well as the incidence of CSVT, were compared between infants born before and after adding routine MRV to post-rewarming magnetic resonance imaging (MRI).

RESULTS

Before routine inclusion of MRV, 209 babies were cooled, and 25 (12%) underwent MRV. Only one baby (0.5%) was diagnosed with CSVT in that period, and it was detected by structural MRI, then confirmed with MRV. After the inclusion of routine MRV, 82 infants were cooled. Of these, 74 (90%) had MRV and none were diagnosed with CSVT.

CONCLUSION

CSVT is uncommon in our cohort of infants receiving therapeutic hypothermia for neonatal encephalopathy. Inclusion of routine MRV in the post-rewarming imaging protocol was not associated with increased detection of CSVT in this population.

IMPACT

Cerebral sinovenous thrombosis (CSVT) in infants with NE receiving TH may not be as common as previously indicated. The addition of MRV to routine post-rewarming imaging protocol did not lead to increased detection of CSVT in infants with NE. Asymmetry on MRV of the transverse sinus is a common anatomic variant. MRI alone may be sufficient in indicating the presence of CSVT.

A novel echocardiography method to assess upper body systemic blood flow in preterm infants and comparison with superior vena cava flow measurement

To evaluate feasibility, reproducibility, and prognostic value of a new echocardiographic method to assess systemic arterial blood flow directed to the upper part of the body (UBAF, upper body arterial flow) alternative to superior vena cava flow (SVCF) measurement. We performed echocardiographic evaluations in 106 infants in the first 2 days of life to obtain SVCF, left ventricle output (LVO), UBAF, and standard parameters of patent ductus arteriosus (PDA) significance. UBAF was calculated by subtracting from LVO the aortic arch blood flow measured immediately distally to the origin of the left subclavian artery. Main outcome measures: UBAF and SVCF agreement was assessed by Bland-Altman analysis in terms of bias, limits of agreement and repeatability index. The Intraclass Correlation Coefficient was used to measure the strength of inter-rater agreement. The agreement between UBAF and SVCF was high. The Concordance Correlation Coefficient (CCC) was 0.7434. (CCC 0.7434, 95% C.I. [0.656, 0.8111]). There was a good absolute agreement between the two raters ICC = 0.747; p value < 0.0001; 95%CI [0.601; 0.845]. Adjusting for confounding factors (BW, GA, PDA) included in the model, there was a statistically significant relationship between UBAF and SVCF.

CONCLUSION

UBAF showed a strong agreement with the SCVF with a better reproducibility. Our data support UBAF as a potentially useful marker of cerebral perfusion in the evaluation of preterm infants.

WHAT IS KNOWN

• Low SVC (superior vena cava) flow in the neonatal period has been associated with periventricular haemorrhage and unfavourable long-term neurodevelopmental outcome. • Ultrasound measurement of flow in SVC shows relatively high inter-operator variability.

WHAT IS NEW

• Our study highlights how much overlap there is between upper-body arterial flow (UBAF) measurement and SCV flow measurement. UBAF is easier to perform and has a strong correlation with better reproducibility. • UBAF may replace measurement of cava flow as a method for haemodynamic monitoring of unstable preterm and asphyxiated infants.

Arterial pressure is not reflective of right ventricular function in neonates with hypoxic ischemic encephalopathy treated with therapeutic hypothermia

AIM

to evaluate the correlation of recovery of arterial pressure with physiological recovery among patients with hypoxic ischemic encephalopathy undergoing therapeutic hypothermia.

METHODS

At 24 h postnatal age, we compared 53 neonates of whom 22 (41%) were inotrope-treated to those untreated with cardiovascular medications.

RESULTS

Inotrope-treated patients had persistent severe right ventricular (RV) dysfunction and evidence of abnormal brain tissue oxygen delivery, despite recovered arterial pressure.

CONCLUSION

Arterial pressure is not reflective of RV function and the need for inotropic agents may be reflective of abnormal brain tissue oxygen delivery.

Time series analysis of non-invasive hemodynamic monitoring data in neonates with hypoxic-ischemic encephalopathy

Background and aims

Hemodynamic instability is common in neonates with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH). Rewarming is a critical period and non-invasive circulatory monitoring may help guide cardiovascular supportive therapy. The aim of the study was to provide a comprehensive analysis of cardiac function parameters during TH and its relation to neurodevelopmental outcome.

Methods

In a prospective, observational study, 26 neonates with moderate-severe HIE were enrolled, born between 2016 and 2019. A hemodynamic monitor based on electrical velocimetry (ICON, Osypka Medical GmbH, Berlin, Germany) was used. Heart rate (HR), stroke volume (SV), cardiac output (CO) data were recorded continuously throughout TH and rewarming. Neurological outcome was assessed at 2 years of age using the Bayley Scales of Infant Development II. edition. Favorable outcome was defined as >70 points on both the psychomotor and mental scales. Time-series analysis was used and features of cardiac function were described to perform logistic regression modeling for outcome prediction.

Results

Fourteen (54%) patients had favorable and 12 (46%) had adverse outcome. Data collection started from median [IQR] of 11.8 [7.0; 24.3] hours (h) of life and lasted until 84.0. [81.8; 87.0] h. During TH, the mean HR of the favorable outcome group was significantly lower than that of the adverse outcome group (86 ± 13/min vs. 104 ± 18/min, p = 0.01). During rewarming HR increased similarly in both groups. SV was unaffected by rewarming, and showed a slowly increasing trend. SV of the favorable outcome group was significantly higher compared to the adverse outcome group (1.55 ± 0.23 ml/kg vs. 1.29 ± 0.30 ml/kg, p = 0.035). In line with this, CO was similar in both groups (136 ± 27 ml/kg/min vs. 134 ± 36 ml/kg/min), and a significant 25% increase in CO was observed during rewarming. Based on multiple regression modeling, HR during TH was independently associated with neurological outcome (p = 0.023).

Conclusion

Based on continuous hemodynamic monitoring, patients with adverse outcome have lower SV and higher HR to achieve similar CO to patients with favorable outcome during TH. HR during hypothermia is independently associated with the neurodevelopmental outcome.

Safety and Feasibility of Riociguat Therapy for the Treatment of Chronic Pulmonary Arterial Hypertension in Infancy

The effects of riociguat, an oral-soluble guanylate-cyclase stimulator, were studied in 10 infants with chronic pulmonary arterial hypertension. Respiratory status (n = 8/10), right heart dilation (n = 7/10), function (n = 9/10), and chronic pulmonary arterial hypertension (n = 8/10) improved. Median decrement in systolic (12 [4, 14]), diastolic (14 [7, 20]), and mean arterial (14 [10, 17]) pressures were noted; no critical hypotension or hypoxemia occurred.

Noradrenaline use for neonatal circulatory support

AIM

Noradrenaline (NA) has been used in preterm and term infants for circulatory support due to conditions including sepsis and pulmonary hypertension of the newborn. Treatment in neonates varies widely between institutions and respective neonatologists. The aim of this study is to determine the indications, use and effects of NA in preterm and term infants requiring circulatory support at the Royal Brisbane and Women's Hospital neonatal intensive care unit. We also aim to determine whether there were any differences between neonates who survived versus those who died after NA treatment.

METHODS

Data were collected from Royal Brisbane and Women's Hospital neonatal unit database including preterm and term infants between 1 January 2016 and 31 May 2021. Analysis included indication for use, blood pressure response, perfusion parameters, haemodynamic indicators and adverse effects.

RESULTS

NA treatment was documented in 37 patients requiring treatment of cardiovascular compromise. In 11 (30%) of these infants the indication for use was due to sepsis, 19 (51%) infants had pulmonary hypertension of the newborn, and 7 (19%) infants were diagnosed with hypotension prior to NA administration. Infants who subsequently died (49%) represented a younger gestational age population and exhibited worse cardiac compromise prior to NA administration. Tachycardia occurred in 15 (31%) infants and 1 (2.7%) infant developed transient hypertension. Overall improvement in poor tissue perfusion was seen after NA use.

CONCLUSION

NA use in treating neonates requiring circulatory support appears to be effective. Further prospective trials into NA use as a first- or second-line inotropic agent would be valuable.

Neonatal Vital Sign Trajectories and Risk Factors During Transport Within a Regional Care Network

OBJECTIVE

The aim of this study was to characterize vital sign abnormalities, trajectories, and related risk factors during neonatal transport.

METHODS

We performed a retrospective analysis of neonates transported within a US regional care network in 2020 to 2021. Demographic and clinical data were collected from electronic records. Group-based trajectory modeling was applied to identify groups of neonates who followed distinct vital sign trajectories during transport. Patients with conditions likely to impact the assessed vital were excluded. Risk factors for trajectories were examined using modified Poisson regression models.

RESULTS

Of the 620 neonates in the study, 92% had one abnormal systolic blood pressure (SBP) measure, approximately half had an abnormal heart rate (47%) or temperature (56%), and 28% had an abnormal oxygen saturation measure during transport. Over half (53%) were in a low and decreasing SBP trajectory, and 36% were in a high and increasing heart rate trajectory. Most infants ≤ 28 weeks postmenstrual age had 2 or more concerning vital sign trajectories during transport.

CONCLUSION

Abnormal vital signs were common during neonatal transport, and potentially negative trajectories in heart rate and SBP were more common than temperature or oxygen saturation. Transport teams should be trained and equipped to detect concerning trends and respond appropriately while en route.

Hypothermia and heart rate variability in a healthy newborn piglet model

Decreased heart rate variability (HRV) may be a biomarker of brain injury severity in neonatal hypoxic-ischemic encephalopathy for which therapeutic hypothermia is standard treatment. While therapeutic hypothermia may influence the degree of brain injury; hypothermia may also affect HRV per se and obscure a potential association between HRV and hypoxic-ischemic encephalopathy. Previous results are conflicting. This study aimed to investigate the effect of hypothermia on HRV in healthy, anaesthetised, newborn piglets. Six healthy newborn piglets were anaesthetised. Three piglets were first kept normothermic (38.5-39.0 °C) for 3 h, then exposed to hypothermia (33.5-34.5 °C) for 3 h. Three piglets were first exposed to hypothermia for 3 h, then rewarmed to normothermia for 3 h. Temperature and ECG were recorded continuously. HRV was calculated from the ECG in 5 min epochs and included time domain and frequency domain variables. The HRV variables were compared between hypothermia and normothermia. All assessed HRV variables were higher during hypothermia compared to normothermia. Heart rate was lower during hypothermia compared to normothermia and all HRV variables correlated with heart rate. Hypothermia was associated with an increase in HRV; this could be mediated by bradycardia during hypothermia.

[Fetal and pediatric cardiovascular physiology : Things you should know as an (pediatric) anesthesiologist]

Immediately after birth the physiology of the cardiovascular system of the neonate undergoes some significant changes. The first breaths in life and the inflation of the lungs lead to a considerable drop in pulmonary arterial resistance. This results in the closure of the foramen ovale and ductus arteriosus; however, during the first weeks of life a sharp rise in pulmonary vascular resistance caused by hypoxia, hypercapnia and excessive positive pressure ventilation can lead to the reopening of the ductus arteriosus. This may result in subsequent strain of the left heart. In order to anticipate the reopening of the ductus arteriosus, it is recommended to measure the saturation of peripheral oxygen not only preductal (right hand), but also postductal (feet).An excessive volume therapy should be avoided as the neonatal myocardium is hallmarked by low cardiac compliance, reduced contractility and reduced ventricular filling.Until now there is still no uniform definition of hypotension in pediatric patients. Blood pressure values that are measured in awake children or are derived from the 50% age percentile values can thus only be used as approximate values. In all cases it is mandatory to recognize and consistently treat hypotension during pediatric anesthesia in order to prevent postoperative organ damage, particularly of the brain.The transcranial measurement of cerebral regional oxygen saturation (c‑rSO₂) by means of near-infrared spectroscopy (NIRS) provides valuable information about regional tissue oxygenation of the brain. This enables conclusions about the state of the multifactorial cerebral perfusion to be drawn. In this way monitoring of the hypoxia sensitive cerebral tissue can be accomplished and should be used in premature infants and neonates. When measuring a baseline in awake patients, a 20% drop of c‑rSO₂ from this baseline should be challenged and treated if necessary.

The effect of norepinephrine on clinical and hemodynamic parameters in neonates with shock: a retrospective cohort study

There is limited data on the cardiovascular effects of norepinephrine (NE) in neonates. Our objective was to describe the clinical responses in neonates treated with NE infusion. This retrospective cohort study included neonates with evidence of shock and those who received NE infusion.

PRIMARY OUTCOME

changes in mean blood pressure (MBP) at 6, 12, and 24 h post-initiation of NE.

SECONDARY OUTCOMES

Changes in (i) diastolic BP, systolic BP, and vasoactive inotrope score (VIS) at 6, 12, and 24 h, (ii) urine output after initiation of NE ii) pH, lactate, fraction of inspired oxygen (FiO2) after initiation of NE, and (iv) adverse outcomes. Fifty infants received NE with mean (SD) gestational age of 34.3 (4.3) weeks and a mean birth weight of 2215 (911) g. Treatment began at a median age of 36 (IQR: 15.2, 67.2) hours of life and lasted 30.5 (IQR: 12.7, 58) hours. MBP improved from 34.4 mm Hg (SD: 6.6) at baseline to 39.4 mm Hg (SD: 10.5, p < 0.001) at 6 h, to 39.6 mm Hg (SD: 12.1, p = 0.002) at 12 h and to 40.4 mm Hg (SD: 15.5, p = 0.004) at 24 h after NE initiation. Vasoactive inotrope score declined from 30 (20, 32) to 10 (4, 30; p < 0.001) at 24 h. Urine output improved within 24 h [1.5 ml/kg/h (0.5, 2.3) at baseline to 3 (1.9, 4.3) at 24 h; p = 0.04]. Oxygen requirement decreased after NE initiation.

CONCLUSION

The use of NE appears to be effective and safe for treating systemic hypotension in neonates.

TRIAL REGISTRATION

Being a retrospective study, trial registration was not considered.

WHAT IS KNOWN

• Dopamine has traditionally been used as the initial agent for treatment of neonatal hypotension. • Norepinephrine has recently been recommended as the first-choice vasopressor agent to correct hypotension in adults and pediatric patients, with insufficient data on the cardiovascular effects of NE in neonates What is new: • Mean blood pressure improved significantly at 6, 12, and 24 h with reduction in vasoactive infusion score at 12 and 24 h after norepinephrine infusion. • No significant change in heart rate or abnormal abdominal adverse effects noted in this study.

Effect of Delayed Umbilical Cord Clamping on Hemodynamic Instability in Preterm Neonates below 35 Weeks

INTRODUCTION

Delaying umbilical cord clamping facilitates postnatal transition in neonates but evidence on its effect in reducing hemodynamic instability in preterm neonates is inconclusive.

AIMS

To evaluate delayed cord clamping (DCC) in reducing the incidence of hemodynamic instability in preterm neonates below 35 weeks gestational age admitted to the neonatal intensive care unit.

METHODS

Neonates between 25 weeks and 34 weeks and 6 days gestation were enrolled. Hemodynamic and respiratory parameters were monitored over 48 h. Hemodynamic instability was defined as persistent tachycardia and/or hypotension necessitating therapy.

RESULTS

The DCC cohort included 62 neonates with an equal number in the non-DCC group. The birth weight [mean ± standard deviation (SD)] was 1332.90 ± 390.05 g and the gestational age (mean ± SD) was 31.64 ± 2.52 weeks. Hemodynamic instability was noted in 18/62 (29%) neonates in the DCC cohort and 29/62 (46.7%) in the non-DCC group; relative risk (RR) 0.62 [95% confidence interval (CI) 0.38-0.99] (p = 0.023). The duration of inotrope requirement in the DCC cohort (mean ± SD) was 38.38 ± 16.99 h compared to 49.13 ± 22.90 h in the non-DCC cohort (p = 0.090). Significantly higher systolic, diastolic and mean arterial pressures were noted from 6 h to 48 h in the DCC cohort (p < 0.001). The severity of respiratory distress and FiO2 requirement was also less in the first 24 h. There was no difference in the incidence of patent ductus arteriosus, late-onset sepsis or mortality.

CONCLUSION

Delaying umbilical cord clamping at birth by 60 s resulted in significantly lower hemodynamic instability in the first 48 h and higher blood pressure parameters.

Multisystem Inflammatory Syndrome in Neonates Born to Mothers with SARS-CoV-2 Infection (MIS-N) and in Neonates and Infants Younger Than 6 Months with Acquired COVID-19 (MIS-C): A Systematic Review

(1) Introduction: There is an increasing literature describing neonates born to mothers with SARS-CoV-2 infection (MIS-N) and infants infected with SARS-CoV-2 who presented with a severe disease (MIS-C). (2) Methods: To investigate clinical features of multisystem inflammatory syndrome in neonates and infants under six months of age, we used a systematic search to retrieve all relevant publications in the field. We screened in PubMed, EMBASE and Scopus for data published until 10 October 2021. (3) Results: Forty-eight articles were considered, including 29 case reports, six case series and 13 cohort studies. Regarding clinical features, only 18.2% of MIS-N neonates presented with fever; differently from older children with MIS-C, in which gastrointestinal symptoms were the most common manifestation, we displayed that cardiovascular dysfunction and respiratory distress are the prevalent findings both in neonates with MIS-N and in neonates/infants with MIS-C. (4) Conclusions: We suggest that all infants with suspected inflammatory disease should undergo echocardiography, due to the possibility of myocardial dysfunction and damage to the coronary arteries observed both in neonates with MIS-N and in neonates/infants with MIS-C. Moreover, we also summarize how they were treated and provide a therapeutic algorithm to suggest best management of these fragile infants.

A new physiologic-based integrated algorithm in the management of neonatal hemodynamic instability

Physiologic-based management of hemodynamic instability is proven to guide the logical selection of cardiovascular support and shorten the time to clinical recovery compared to an empiric approach that ignores the heterogeneity of the hemodynamic instability related mechanisms. In this report, we classified neonatal hemodynamic instability, circulatory shock, and degree of compensation into five physiologic categories, based on different phenotypes of blood pressure (BP), other clinical parameters, echocardiography markers, and oxygen indices. This approach is focused on hemodynamic instability in infants with normal cardiac anatomy.Conclusion: The management of hemodynamic instability is challenging due to the complexity of the pathophysiology; integrating different monitoring techniques is essential to understand the underlying pathophysiologic mechanisms and formulate a physiologic-based medical recommendation and approach. What is Known: • Physiologic-based assessment of hemodynamics leads to targeted and pathophysiologic-based medical recommendations. What is New: • Hemodynamic instability in neonates can be categorized according to the underlying mechanism into five main categories, based on blood pressure phenotypes, systemic vascular resistance, and myocardial performance. • The new classification helps with the targeted management and logical selection of cardiovascular support.

Cardiorespiratory management of infants born at 22 weeks' gestation: The Iowa approach

The approach to clinical care of infants born at 22 weeks' gestation must be consistent and well-designed if optimal results are to be expected. Publications from several international centers have demonstrated that, although there may be variance in aspects of care in this vulnerable population, treatment should be neither random nor inconsistent. In designing a standardized approach, careful attention should be paid to the unique anatomy, physiology, and biochemistry of this vulnerable patient population. Emerging evidence, suggesting a link between cardiopulmonary health and longer-term sequela, highlights the importance of understanding the relationship between cardiorespiratory illnesses of the 22-week infant, treatments provided, and subsequent cardiopulmonary development. In this review we will provide an overview to our approach to cardiopulmonary assessment and treatment, with a particular emphasis on the importance of early recognition of atypical phenotypes, timely interventions with evidence-based treatments, and longitudinal monitoring.

Low frequency cerebral arterial and venous flow oscillations in healthy neonates measured by NeoDoppler

BACKGROUND

A cerebroprotective effect of low frequency oscillations (LFO) in cerebral blood flow (CBF) has been suggested in adults, but its significance in neonates is not known. This observational study evaluates normal arterial and venous cerebral blood flow in healthy neonates using NeoDoppler, a novel Doppler ultrasound system which can measure cerebral hemodynamics continuously.

METHOD

Ultrasound Doppler data was collected for 2 h on the first and second day of life in 36 healthy term born neonates. LFO (0.04-0.15 Hz) were extracted from the velocity curve by a bandpass filter. An angle independent LFO index was calculated as the coefficient of variation of the filtered curve. Separate analyses were done for arterial and venous signals, and results were related to postnatal age and behavioral state (asleep or awake).

RESULTS

The paper describes normal physiologic variations of arterial and venous cerebral hemodynamics. Mean (SD) arterial and venous LFO indices (%) were 6.52 (2.55) and 3.91 (2.54) on day one, and 5.60 (1.86) and 3.32 (2.03) on day two. After adjusting for possible confounding factors, the arterial LFO index was estimated to decrease by 0.92 percent points per postnatal day (p < 0.001). The venous LFO index did not change significantly with postnatal age (p = 0.539). Arterial and venous LFO were not notably influenced by behavioral state.

CONCLUSION

The results indicate that arterial LFO decrease during the first 2 days of life in healthy neonates. This decrease most likely represents normal physiological changes related to the transitional period. A similar decrease for venous LFO was not found.

Relative Adrenal Insufficiency: Crisis Averted?

Relative adrenal insufficiency (AI) is a disease process commonly associated with preterm birth and critical illness. Further, the incidence of AI is inversely proportional to gestational age. The incidence of AI is likely underreported; however, it is reported to occur in 150-280/1,000,000 live births worldwide. Functional development of the adrenal gland does not occur until after 30 weeks of gestation; however, advances made in neonatal care increase the survivability of infants born well before this period. Among infants with AI, the adrenal gland is transiently incapable of secreting physiologic levels of cortisol in response to stressors. Common and nonspecific signs include hypotension, poor perfusion, and dysregulation of fluid, electrolytes, and euglycemia. Recognition, diagnosis, and steroid therapy is critical, as inappropriately managed AI can lead to an adrenal crisis, shock, and death. Understanding the presentation and common risk factors for developing relative AI is crucial for quick diagnosis and timely management to prevent morbidity and mortality in this vulnerable population.

Maximum vasoactive-inotropic score and mortality in extremely premature, extremely low birth weight infants

OBJECTIVE

To determine the relationship between maximum vasoactive-inotropic (VIS^max) and mortality in extremely premature (<29 weeks completed gestation), extremely low birth weight (ELBW, <1000 g) infants.

STUDY DESIGN

Single center, retrospective, and observational cohort study.

RESULTS

We identified 436 ELBW, <29 week, inborn infants cared for during the study period. Compared to infants with VIS^max of 0, the frequency of mortality based on VIS^max ranged from 3.3-fold to 46.1-fold. VIS^max > 30 was associated with universal mortality. Multivariable modeling that included gestational age, birth weight, and VIS^max revealed significant utility to predict mortality with negative predictive value of 87.0% and positive predictive value of 84.8% [adjusted AUROC: 0.90, (0.86-0.94)] among patients that received vasoactive-inotropic treatment.

CONCLUSION

VIS^max is an objective measure of hemodynamic/cardiovascular support that was directly associated with mortality in extremely premature ELBW infants. The VIS^max represents an important step towards neonatal precision medicine and risk stratification of extremely premature ELBW infants.

Hemodynamic optimization for neonates with neonatal encephalopathy caused by a hypoxic ischemic event: Physiological and therapeutic considerations

Neonatal encephalopathy due to a hypoxic-ischemic event is commonly associated with cardiac dysfunction and acute pulmonary hypertension; both therapeutic hypothermia and rewarming modify loading conditions and blood flow. The pathophysiological contributors to disease are complex with a high degree of clinical overlap and traditional bedside measures used to assess circulatory adequacy have multiple confounders. Comprehensive, quantitative echocardiography may be used to delineate the relative contribution of lung parenchymal, pulmonary vascular, and cardiac disease to hypotension and/or hypoxemic respiratory failure. In this review, we provide a detailed overview of the contributors to hemodynamic instability following perinatal hypoxic-ischemic injury. Our proposed approach to therapy focuses on physiopathological considerations with interventions individualized to this potentially complex condition and considers the pharmacological idiosyncrasies, which may occur among neonates with NE presenting with multiorgan dysfunction while undergoing therapeutic hypothermia.

Neuroprotection of the Perinatal Brain by Early Information of Cerebral Oxygenation and Perfusion Patterns

Abnormal patterns of cerebral perfusion/oxygenation are associated with neuronal damage. In preterm neonates, hypoxemia, hypo-/hypercapnia and lack of cerebral autoregulation are related to peri-intraventricular hemorrhages and white matter injury. Reperfusion damage after perinatal hypoxic ischemia in term neonates seems related with cerebral hyperoxygenation. Since biological tissue is transparent for near infrared (NIR) light, NIR-spectroscopy (NIRS) is a noninvasive bedside tool to monitor brain oxygenation and perfusion. This review focuses on early assessment and guiding abnormal cerebral oxygenation/perfusion patterns to possibly reduce brain injury. In term infants, early patterns of brain oxygenation helps to decide whether or not therapy (hypothermia) and add-on therapies should be considered. Further NIRS-related technical advances such as the use of (functional) NIRS allowing simultaneous estimation and integrating of heart rate, respiration rate and monitoring cerebral autoregulation will be discussed.

Clinical and echocardiography predictors of response to inhaled nitric oxide in hypoxemic term and near-term neonates

Approximately 40% of hypoxemic term/near-term neonates are nonresponders to inhaled nitric oxide (iNO). Phenotypic characterization of patients less likely to respond may improve diagnostic precision and therapeutic decisions. We conducted a retrospective cohort study of neonates born ≥35 weeks gestation with hypoxemia who received iNO in the first 72 h of life and classified them into responders and nonresponders according to changes in the fraction of inspired oxygen, saturations and/or arterial partial pressure of oxygen after 1 h of administration. Comprehensive targeted neonatal echocardiography (TnECHO) data were collected when performed up to 6 h prior or 24 h after iNO initiation. Descriptive statistics, univariate analysis, and binary logistic regression were used to compare the groups. There were 183 patients included (63% responders) and TnECHO was performed in 54 infants. The presence of lung disease, and particularly meconium aspiration syndrome (p = .004), was associated with nonresponse to iNO. Nonresponders were characterized by a higher need for rescue high-frequency ventilation (p < .001), longer duration of mechanical ventilation (p < .001), and need for oxygen support (p = .003). Pulmonary hypertension documented on TnECHO was present in 96.3% of the patients but there was no difference in frequency or severity of pulmonary hypertension, or rates of low cardiac output between the groups. Moderate-to-severe right ventricular systolic dysfunction (p > .05) and lower left ventricular strain (p < .05) were more likely in the nonresponder group. In summary, response to iNO is influenced by lung disease, choice of ventilation strategy, and perhaps underlying cardiovascular physiology. Prospective pre- and post-iNO echocardiography data may provide novel physiologic insights.

Heart rate variability as possible marker of brain damage in neonates with hypoxic ischemic encephalopathy: a systematic review

Heart rate variability (HRV) is currently considered the most valuable non-invasive test to investigate the autonomic nervous system function, based on the fact that fast fluctuations might specifically reflect changes of sympathetic and vagal activity. An association between abnormal values of HRV and brain impairment has been reported in the perinatal period, although data are still fragmentary. Considering such association, HRV has been suggested as a possible marker of brain damage also in case of hypoxic-ischemic encephalopathy following perinatal asphyxia. The aim of the present manuscript was to review systematically the current knowledge about the use of HRV as marker of cerebral injury in neonates suffering from hypoxic-ischemic encephalopathy. Findings reported in this paper were based on qualitative analysis of the reviewed data. Conclusion: A growing body of research supports the use of HRV as non-invasive, bedside tool for the monitoring of hypoxic-ischemic encephalopathy. The currently available data about the role of HRV as prognostic tool in case of hypoxic ischemic encephalopathy are promising but require further validation by future studies. What is Known: • Heart rate variability (HRV) is a non-invasive monitoring technique to assess the autonomic nervous system activity. • A correlation between abnormal HRV and cerebral injury has been reported in the perinatal period, and HRV has been suggested as possible marker of brain damage in case of hypoxic-ischemic encephalopathy. What is New: • HRV might provide precocious information about the entity of brain injury in asphyxiated neonates and be of help to design early, specific, and personalized treatments according to severity. • Further investigations are required to confirm these preliminary data.

Perioperative management of arteriovenous malformation guided by integrated evaluation of hemodynamics

We aimed to demonstrate the value of monitoring infants with arteriovenous malformation (AVM) during endovascular embolization with integrated evaluation of hemodynamics (IEH) and guiding decisions according to the underlying pathophysiology. This is a retrospective analysis of the perioperative hemodynamics data for 2 complex cases of AVM transferred to Khaula Hospital in Oman for interventional management. We described the value of novel physiological insights gained from comprehensive IEH and provided a systematic approach to the perioperative management. Postoperative targeted neonatal echo (TNE) was used to guide the weaning of the cardiovascular medications within 24 h. Both cases showed significant right ventricle (RV) volume overload before surgery. Narrowing of the pulse pressure (PP) during or after endovascular embolization was used as a marker of compromised systemic blood flow in real time followed by an assessment by TNE to guide the appropriate therapy.Conclusion: Integrated evaluation of hemodynamics is helpful to guide perioperative physiologic-based management of AVM. What is Known: • The preoperative management of hemodynamic compromise due to AVM has been described in many articles. • Perioperative management of AVM and related hemodynamics is a challenge to the intensive care team. What is New: • Integrated evaluation of hemodynamics is a comprehensive assessment and helpful in understanding the underlying physiologic changes during intervention with AVM. • This integrated evaluation can lead to physiologic-based medical recommendation with subsequent improvement.

Use of vasopressin in neonatal hypertrophic obstructive cardiomyopathy: case series

OBJECTIVE

To determine the effect of vasopressin on arterial blood pressure in infants with neonatal hypertrophic obstructive cardiomyopathy (HOCM).

STUDY DESIGN

Retrospective case study in Neonatal ICU involving six infants; five born to mothers with diabetes mellitus (mean gestational age 37.5 ± 0.9 weeks). Vasopressin infusion was started at a mean dose of 0.3 ± 0.2 mU/kg/min.

RESULT

Initiation of vasopressin was followed by improved mean (p = 0.004), systolic (p = 0.028), and diastolic (p = 0.009) arterial pressure within 2 h. Heart rate (p = 0.025) and oxygen requirement (p = 0.021) also declined after initiation. Serum sodium declined initially and recovered by 72 h (p = 0.017).

CONCLUSION

Although there is limited experience with vasopressin use in neonatal HOCM, our case series suggests it may be beneficial for improving systemic hypotension and stabilization of hemodynamics. The potential for hyponatremia is high, necessitating careful fluid/electrolyte management. A prospective randomized trial is necessary to confirm safety and efficacy of vasopressin treatment in neonatal HOCM.

Effects of tilt on cerebral hemodynamics measured by NeoDoppler in healthy neonates

BACKGROUND

Today, there are conflicting descriptions of how neonates respond to tilt. Examining physiologic responses of cerebral blood flow velocities (BFVs) in challenging situations like a tilt requires equipment that can cope with positional changes. We aimed to characterize how healthy term neonates respond to mild cerebral hemodynamic stress induced by a 90° tilt test using the recently developed NeoDoppler ultrasound system.

METHODS

A small ultrasound probe was fixated to the neonatal fontanel by a cap, and measured cerebral BFV in healthy neonates during and after a 90° head-up tilt test, five min in total, at their first and second day of life. Unsupervised k-means cluster analysis was used to characterize common responses.

RESULTS

Fifty-six ultrasound recordings from 36 healthy term neonates were analyzed. We identified five distinct, immediate responses that were related to specific outcomes in BFV, heart rate, and pulsatility index the next two min. Among 20 neonates with two recordings, 13 presented with different responses in the two tests.

CONCLUSIONS

Instant changes in cerebral BFV were detected during the head-up tilt tests, and the cluster analysis identified five different hemodynamic responses. Continuous recordings revealed that the differences between groups persisted two min after tilt.

IMPACT

NeoDoppler is a pulsed-wave Doppler ultrasound system with a probe fixated to the neonatal fontanel by a cap that can measure continuous cerebral blood flow velocity. Healthy neonates present with a range of normal immediate cerebral hemodynamic responses to a 90° head-up tilt, categorized in five groups by cluster analysis. This paper adds new knowledge about connection between immediate responses and prolonged responses to tilt. We demonstrate that the NeoDoppler ultrasound system can detect minute changes in cerebral blood flow velocity during a 90° head-up tilt.

A neonate with intrauterine growth restriction and pseudo-Bartter syndrome due to severe maternal eating disorder: A case report

Maternal diet before and during pregnancy plays an important role for the developing fetus. Any eating disorder in this period can cause transient or/and permanent negative effects on the mother and her offspring.

Anatomic Concordance of Neonatologist-Performed Echocardiography as Part of Hemodynamics Consultation and Pediatric Cardiology

BACKGROUND

Targeted neonatal echocardiography (TnECHO) performed by neonatologists as part of a hemodynamics consultation is increasingly being used in neonatal intensive care units. To minimize delays in obtaining physiologic data, first echocardiograms may be obtained by the neonatal hemodynamics team and reviewed afterward by a pediatric cardiologist. This practice has not been systematically evaluated. The aim of this study was to compare concordance between anatomic findings on TnECHO and pediatric cardiology reports.

METHODS

This was a retrospective evaluation of 339 infants at low risk for congenital heart disease (CHD) admitted to two large referral centers with established neonatal hemodynamics programs who underwent comprehensive TnECHO as their first postnatal echocardiographic examinations. The protocol included comprehensive imaging of intracardiac anatomy, outflow tract concordance and integrity, aortic arch anatomy, pulmonary vein location and flow, and transitional shunts. The hemodynamics consultation note was compared with the cardiology report to determine anatomic concordance or major or minor discrepancies in all first studies.

RESULTS

Anatomic concordance occurred in 97.9% (κ = 0.862; 95% CI, 0.762-0.962; P < .001). There were seven minor discrepancies (small muscular ventricular septal defects and coronary fistulas). The index population included 23 infants (6.7%) with CHD, of whom only one (0.3%) had a ductal-dependent lesion (coarctation of the aorta) which was correctly identified by both teams.

CONCLUSIONS

The rate of major CHD in patients considered eligible for hemodynamics consultation was low, and there was high diagnostic concordance between trained neonatal hemodynamics specialists and pediatric cardiology. First echocardiograms obtained by subspecialty neonatologists may provide imaging of sufficient quality to evaluate a critically unwell neonate with low suspicion for critical CHD lesions. These results should not be extrapolated to infants in whom CHD is suspected. This study highlights the importance of formalized, rigorous, and standardized training for neonatologists with hemodynamics expertise who perform timely assessments using TnECHO.

What Inotrope and Why?

Primary function of cardiovascular system is to meet body's metabolic demands. The aim of inotrope therapy is to minimise adverse impact of cardiovascular compromise. Current use of inotropes is primarily guided by the pathophysiology of cardiovascular compromise and anticipated actions of inotropes. Lack of significant reduction in morbidity and mortality associated with cardiovascular compromise despite inotrope use, highlights major gaps in our understanding of circulatory targets, thresholds and choices of inotrope therapy. Thus far, prevention of cardiovascular compromise remains the most effective strategy to optimize outcomes. Studies of alternative design are needed for further advancement in cardiovascular therapy in neonates.