Randomised trial of dobutamine versus placebo for low superior vena cava flow in preterm infants: Long-term neurodevelopmental outcome

Superior Vena Cava Flow in Preterm Infants and Neonatal Outcomes: A Systematic Review

Superior vena cava (SVC) flow has been considered a surrogate marker of systemic blood flow in neonates. We conducted a systematic review to evaluate the association between low SVC flow recorded during the early neonatal period and neonatal outcomes. We searched the following databases (until December 9, 2020; updated October 21, 2022): PROSPERO, OVID Medline, OVID EMBASE, Cochrane Library (CDSR and Central), Proquest Dissertations and Theses Global, and SCOPUS using controlled vocabulary and key words representing the concepts "superior vena cava" and "flow" and "neonate." Results were exported to COVIDENCE review management software. The search retrieved 593 records after the removal of duplicates, of which 11 studies (nine cohorts) met the inclusion criteria. The majority of the studies included infants born at <30 weeks of gestation. The included studies were assessed as high risk of bias in terms of the incomparability of the study groups, with infants in the low SVC flow group noted to be more immature than those in the normal SVC flow group or subjected to different cointerventions. We did not conduct meta-analyses in view of the significant clinical heterogeneity noted in the included studies. We found little evidence to suggest that SVC flow in the early neonatal period is an independent predictor for adverse clinical outcomes in preterm infants. Included studies were assessed at high risk of bias. We conclude that SVC flow interpretation for prognostication or for making treatment decisions should be restricted to the research setting for now. We highlight the need for strengthened methods in future research studies. KEY POINTS: · We studied whether low SVC flow in the early neonatal period is a marker for adverse outcomes in preterm infants.. · There is insufficient evidence to conclude that low SVC flow is a valid predictor of adverse outcomes.. · There is insufficient evidence to conclude that SVC flow-directed hemodynamic management improves clinical outcomes..

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.

Should SVC flow be a routine measure when performing targeted neonatal echocardiography? A narrative review

Superior vena cava is commonly used in neonatal hemodynamics and is suggested to be the best available non-invasive marker for systemic circulation in preterm infants. Inter- and intra-observer variability remain to be an issue. Its association with neonatal outcomes is has not been established. This is a narrative review about this marker, its use, and its potential pitfalls.

OBJECTIVE

This is a narrative review about SVC flow in preterm infants, physiology, techniques of measurement and its potential association with outcomes.

SOURCES

Literature revie mainly PubMED.

SUMMARY OF THE FINDINGS

SVC flow measurement has some limitations and pitfalls.

CONCLUSIONS

SVC flow association with neonatal outcomes, still needs to be established in further research.

Effects of Catecholamines on Blood Flow in Preterm Infants: A Subanalysis of PICC-MBF Trial

INTRODUCTION

This study evaluated the correlation between skin blood flow and systemic blood flow and whether skin blood flow can determine the circulatory effects of dopamine and dobutamine on blood flow in very low birth weight (VLBW) infants.

METHODS

This study was a subanalysis of the PICC-MBF randomized controlled trial. The correlation between skin blood flow and echocardiographic findings was examined. Changes in skin blood flow and blood pressure before and after initiation or dose increase of dopamine and dobutamine were also evaluated.

RESULTS

Two hundred and thirty-four participants underwent echocardiography. Skin blood flow was significantly correlated with supra vena cava (SVC) flow (r = 0.31, p < 0.001). Receiver operator characteristic analysis revealed that skin blood flow <17 mL/min effectively detected SVC flow <41 mL/min (area under the curve = 0.83, p < 0.001). Dobutamine significantly increased skin blood flow after initiation or dose increase (p = 0.033) without increasing blood pressure. However, dopamine significantly increased both skin blood flow (p = 0.010) and blood pressure (p < 0.001).

CONCLUSIONS

Our findings indicated that skin blood flow could be used as a surrogate marker of systemic blood flow in VLBW infants and revealed differences in the effects of dopamine and dobutamine on circulation.

Use of norepinephrine in preterm neonates with dopamine-resistant shock: a retrospective single-centre cross-sectional study

BACKGROUND

Norepinephrine (NE) is recommended for children and full-term neonates (born at >37 gestational weeks) with septic shock. Meanwhile, data on the effectiveness of NE in preterm neonates are still limited. This study aimed to evaluate the clinical efficacy of NE in preterm neonates with dopamine-resistant shock compared with that in full-term neonates.

METHODS

This was a single-centre, retrospective (January 2010-December 2020) cohort study of neonates with persistent shock despite adequate fluid resuscitation and dopamine or dobutamine administration at ≥10 μg/kg/min. Medical records of neonates treated with NE were retrospectively reviewed to collect respiratory and haemodynamic parameters and results of arterial blood gas (ABG) tests before and 8 hours after NE infusion. The effectiveness of NE was assessed using changes in clinical parameters and multiple regression models for mortality among subgroups of preterm and full-term neonates.

RESULTS

Ninety-two neonates (76% preterm) who received NE infusion were included in the study. NE infusion was started after a median of 7 hours (IQR 2-19 hours) after shock onset. Among the preterm neonates, the maximum dose of NE infusion was 0.5 (IQR 0.3-1.0) µg/kg/min with a median duration of 45 (IQR 24.0-84.5) hours. Haemodynamic dysfunction was ameliorated with increased blood pressure, decreased heart rate and improved ABG results. Preterm neonates with septic shock tended to have a reduced response to NE; however, preterm neonates with persistent pulmonary hypertension of the newborn tended to have a better response. Thirty-four (37%) neonates died in our cohort. The timing, dose and duration of NE use were not associated with neonatal mortality.

CONCLUSIONS

Although using NE effectively improves clinical parameters in preterm neonates with dopamine-resistant shock, our study is underpowered to identify the association between NE infusion and mortality in preterm neonates with dopamine-resistant shock.

Cerebral Blood Flow Monitoring in High-Risk Fetal and Neonatal Populations

Cerebrovascular pressure autoregulation promotes stable cerebral blood flow (CBF) across a range of arterial blood pressures. Cerebral autoregulation (CA) is a developmental process that reaches maturity around term gestation and can be monitored prenatally with both Doppler ultrasound and magnetic resonance imaging (MRI) techniques. Postnatally, there are key advantages and limitations to assessing CA with Doppler ultrasound, MRI, and near-infrared spectroscopy. Here we review these CBF monitoring techniques as well as their application to both fetal and neonatal populations at risk of perturbations in CBF. Specifically, we discuss CBF monitoring in fetuses with intrauterine growth restriction, anemia, congenital heart disease, neonates born preterm and those with hypoxic-ischemic encephalopathy. We conclude the review with insights into the future directions in this field with an emphasis on collaborative science and precision medicine approaches.