Oscillometric arterial blood pressure in haemodynamically stable neonates in the first 2 weeks of life

Active versus restrictive approach to isolated hypotension in preterm neonates: A Systematic Review, Meta-analysis and GRADE based Clinical Practice Guideline

OBJECTIVE

Isolated hypotension (IH) without any clinical or biochemical features of poor perfusion is a common occurrence in very preterm infants (VPTI). There exists no recommendations guiding its management.The objective of this review was to compare the effect of active vs. restrictive approach to treat IH in VPTI.

METHODOLOGY

Medline, Embase and Web of Science were searched until 1st April 2024. RCTs and non-RCTs were included. Mortality, major brain injury (MBI) (intraventricular hemorrhage >  grade 2 or cystic periventricular leukomalacia), mortality or neurodevelopmental impairment (NDI) at 18-24 months' corrected age were the critical outcomes evaluated.

RESULTS

44 studies were included: 9 were synthesized in a meta-analysis and 35 studies in the narrative review. Clinical benefit or harm could not be ruled out for the outcomes from the meta-analyses of RCTs. Meta-analysis of 3 non-RCTs suggested that active treatment of IH in VPTI of <  24 hours of life possibly increased the odds of MBI (aOR: 95% CI 1.85 (1.45; 2.36), very low certainty). Meta-analysis of 2 non-RCTs that had included VPTI <  72 hours indicated a possibly decreased risk of MBI (aOR: 95% CI 0.44 (0.24; 0.82), very low certainty) and NEC ≥  stage 2 (aOR: 95% CI 0.61 (0.41; 0.92), very low certainty) with active treatment of IH. Active treatment of IH in the first 24 hours possibly increased the risk of mortality or long-term NDI (aOR: 95% CI 1.84 (1.10; 3.09), very low certainty) and the risk of hearing loss at 2 years (aOR: 95% CI 3.60 (1.30; 9.70), very low certainty). Clinical benefit or harm could not be ruled out for other outcomes. There was insufficient evidence with respect to preterm neonates of ≥  32 weeks.

CONCLUSIONS

IH may not be treated in VPTI in the first 24 hours. However, IH occurring between 24 hours - 72 hours of life may be treated. The evidence certainty was very low.

Neonatal reference values and nomograms of systemic vascular resistances estimated with electrical cardiometry

OBJECTIVE

Scanty data are available about neonatal systemic vascular resistances (SVR). We aim to provide reference values and nomograms for neonatal SVR.

DESIGN

Multicenter, cross-sectional,descriptive study performed in France and Italy. Neonates with complete hemodynamic stability were enrolled. Non-invasive measurements of SVR by electrical cardiometry performed once, after the first 72 h and before the 7th day of postnatal age.

RESULTS

We studied 1094 neonates: SVR was correlated with gestational age (ρ = -0.55, adj-r = -0.46, p < 0.001) and birth weight (ρ = -0.59, adj-r = -0.45, p < 0.001) irrespective of newborn sex. The relationships between SVR, gestational age and birth weight were represented by power equations and SVR was decreasing with increasing age and weight. Age- and weight-based SVR nomograms had optimal goodness-of-fit (non-linear R2 ≥0.74). Similar results were obtained for body surface indexed-SVR.

CONCLUSIONS

In hemodynamically stable neonates, SVR decrease with increasing gestational age and birth weight. Specific gestational age and birth weight-based nomograms are provided for the clinical interpretation.

Neonatal Shock: Current Dilemmas and Future Research Avenues

Neonatal shock presents a complex clinical challenge and is one of the leading causes of mortality. Traditionally, neonatal shock is equated to hypotension, and therapeutics are often initiated based on low blood pressure (BP) values alone. This fails to address the underlying goal of optimizing the tissue perfusion resulting in both over- and under-treatment of neonatal shock. Also, what defines a normal BP in neonates is still a contentious topic. Further, the most appropriate way of measuring BP in neonates with shock is still debated. Shock secondary to transient circulatory instability and patent ductus arteriosus, conditions that are unique to preterm neonates, have not been researched adequately. Treatment of myocardial dysfunction secondary to perinatal asphyxia, a leading cause of neonatal mortality, is still a conundrum. Quite similarly, there are only a handful of controlled trials evaluating therapeutics in some of the other commonly encountered conditions, namely, septic shock and hypoperfusion secondary to pulmonary hypertension. Even the universally practiced intervention of volume expansion with crystalloid boluses in shock is not backed by high-certainty evidence in neonates. Though the diagnostic modalities of functional echocardiography and near-infrared spectroscopy have aided greatly in the management of neonatal shock in recent years, these have not been proven to be associated with improved critical clinical outcomes such as mortality and major brain injury. To conclude, neonatologists often rely on limited evidence, mostly anecdotal, when treating neonatal shock. This review critically examines the current evidence with respect to various aspects of neonatal shock with an objective to identify the lacunae in the literature that may fuel future research, eventually paving the way to efficacious, safe and evidence-based clinical practice.

Oscillatory Blood Pressure Values in Newborn Infants: Observational Data Over Gestational Ages

INTRODUCTION

Normative blood pressure (BP) values on preterm infants exist but are based on small cohorts of infants. Utilizing electronic medical records (EMR), we can explore earlier gestational ages (GA) and follow their progression to 40 weeks corrected gestational age (CGA).

METHODS

A retrospective cohort study of infants within the SSM Health System from July 1, 2013 through June 30, 2023. Infants born at >22 0/7 weeks but <41 weeks GA were included if any BP measurements existed (n = 29,323 infants, 1.4 million BPs). Data were extracted electronically from EMR using Microsoft SQL. Systolic BP (SBP), mean arterial pressures (MAP), and diastolic BP (DBP) were determined for each week of life from birth and percentile ranges (1st to 99th) for infants alive at CGA, and BP patterns for GA determined.

RESULTS

Percentiles for SBP, DBP, and MAP are provided. There is a rapid increase in BP at all gestations during the first 2 weeks, thus BP values are higher at any CGA in infants born at an earlier GA than infants born at that GA. For MAP values between the 5th and 10th percentile, the GA is appropriate for first week and then use CGA + 5 mm Hg. After the first week, 2.8 X CGA is between 90 and 95 percentile for SBP.

CONCLUSIONS

The BP is dependent on the GA at birth and the CGA when it is measured. SBP, MAP, and DBP all increase rapidly in the 2 weeks of life prior to a gradual increase over time.

Blood pressure in preterm infants with bronchopulmonary dysplasia in the first three months of life

BACKGROUND

Neonatal hypertension is common in preterm infants with bronchopulmonary dysplasia (BPD). Our study aimed to examine blood pressure variation in the first three months of life in preterm BPD patients.

METHODS

We conducted a retrospective, single-centre study at the Neonatal Intensive Care Unit of the University of Szeged, Hungary. We collected blood pressure data from 26 preterm infants (born at < 30 weeks gestation) with moderate or severe BPD over three years (2019-2021). We calculated the BPD group's daily average blood pressure values and used previously defined normal blood pressure values from a preterm patient group born at < 30 weeks gestation as a reference. We used 19,481 systolic, diastolic and mean blood pressure measurement data separately to calculate daily average blood pressures.

RESULTS

We found a statistically significant correlation between the blood pressure values of the BPD patient group and the reference data. The difference between the blood pressure curve of the group with BPD and that of the reference group was also statistically significant. We also analysed individual patients' daily average blood pressure values and found that 11 patients (42%) had hypertensive blood pressure values for three or more days within the first 90 days of life. Within this group, our statistical analysis showed a 25% chance of acute kidney injury.

CONCLUSION

The blood pressure of the BPD group not only correlated with but also significantly differed from the reference data. Hypertension lasting three or more days occurred more frequently in patients with acute kidney injury accompanied by BPD.

Neonatal blood pressure by birth weight, gestational age, and postnatal age: a systematic review

BACKGROUND

Blood pressure is a vital hemodynamic marker during the neonatal period. However, normative values are often derived from small observational studies. Understanding the normative range would help to identify ideal thresholds for intervention to treat hypotension or hypertension. Therefore, the aim of this study was to assess observed blood pressure values in neonates who have not received any blood-pressure modifying treatments from birth to three months postnatal age and whether these vary according to birth weight, gestational age and postnatal age.

METHODS

This was a systematic review. A literature search was conducted in MEDLINE, PubMed, Embase, Cochrane Library, and CINAHL from 1946 to 2017 on blood pressure in neonates from birth to 3 months of age (PROSPERO ID CRD42018092886). Unpublished data were included where appropriate.

RESULTS

Of 3,587 non-duplicate publications identified, 30 were included (one unpublished study). Twelve studies contained data grouped by birth weight, while 23 contained data grouped by gestational age. Study and clinical heterogeneity precluded meta-analyses thus results are presented by subgroup. A consistent blood pressure rise was associated with increasing birth weight, gestational age, and postnatal age. In addition, blood pressure seemed to rise more rapidly in the most preterm and low birth weight neonates.

CONCLUSION

Despite blood pressure increasing with birth weight, gestational age, and postnatal age, there was marked blood pressure variability observed throughout. To better define hypotension and hypertension, future studies should develop consistent approaches for factors related to blood pressure variability, including the method and timing of measurement as well as statistical control of relevant patient characteristics.

Common Clinical Scenarios of Systemic Hypertension in the NICU

Hypertension affects ∼1% to 3% of newborns in the NICU. However, the identification and management of hypertension can be challenging because of the lack of data-driven diagnostic criteria and management guidelines. In this review, we summarize the most recent approaches to diagnosis, evaluation, and treatment of hypertension in neonates and infants. We also identify common clinical conditions in neonates in whom hypertension occurs, such as renal vascular and parenchymal disease, bronchopulmonary dysplasia, and cardiac conditions, and address specific considerations for the evaluation and treatment of hypertension in those conditions. Finally, we discuss the importance of ongoing monitoring and long-term follow-up of infants diagnosed with hypertension.