Normative blood pressure data for Indian neonates

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 Unpublished data were included where appropriate.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Of 3,587 non-duplicate publications identified, 30 were included (one unpublished study).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.

Oral versus intravenous sildenafil for pulmonary hypertension in neonates: a randomized trial

BACKGROUND

Sildenafil is the drug of choice for neonatal pulmonary hypertension in developing countries where inhaled nitric oxide is not available. Available as oral and intravenous preparation - no study has been done in the past to compare the two forms. Each has its own benefits - but requires comparison in terms of efficacy and safety. This study was done to compare the efficacy of oral versus intravenous (IV) sildenafil in infants with mild to moderate pulmonary hypertension.

METHODS

An open labelled randomized trial was conducted in a neonatal intensive care unit of urban tertiary hospital in western India between February 2019 to December 2020. Infants born after 34 weeks of gestation with Pulmonary arterial pressure (PAP) > 25 mm Hg measured by echocardiography, within 72 h of birth, were enrolled for the study. Participants were randomly assigned to receive sildenafil either orally or by intravenous route. Primary outcome was the time taken for PAP to decrease below 25 mm Hg. Secondary outcomes were time taken for oxygenation index to decrease by 25%, duration of invasive and non-invasive mechanical ventilation, nasal oxygen, hospital stay, time to achieve full feeds, mortality, and side effects.

RESULTS

Forty patients were enrolled. The baseline characteristics of neonates in both groups were similar except for APGAR scores at 1 min and 5 min, with oral group having lower score [MEDIAN (IQR) 5.00 (4.00- 7.00) and 7.00 (6.00- 8.00)] compared to IV group [MEDIAN (IQR) 7.00 (6.00-8.00) and 9.00 (8.00-9.00)] respectively. Time taken for PAP to decrease below 25 mm was not statistically different between the oral and intravenous groups. Systemic hypotension occurred in 4 neonates of the intravenous group but none in the oral group.

CONCLUSION

Oral and intravenous sildenafil had equal efficacy at reducing PAP in neonatal pulmonary hypertension, albeit intravenous sildenafil use was associated with a greater complication rate.

TRIAL REGISTRATION

Trial was registered in the clinical trials registry of India [ CTRI/2019/04/018781 ][25/04/2019].

Single blood pressure chart for children up to 13 years to improve the recognition of hypertension based on existing normative data

OBJECTIVE

To produce a single 'growth-chart-style' blood pressure (BP) chart with clear diagnostic thresholds to assist paediatricians to make prompt and accurate diagnoses of hypertension.

DESIGN

The well-established but complex published data on normal BP ranges in prepubertal children were identified and analysed to determine if it was possible to produce a single, user-friendly, colour-coded chart, showing diagnostic hypertension thresholds for systolic and diastolic BP without losing clinically important information.

RESULTS

There were sufficient published normative childhood BP data available to define systolic and diastolic BP centiles from term onwards but only sufficient to determine systolic BP centiles from 28 weeks of gestation to term. Up to 13 years of age, it was possible to combine boys' and girls' data without loss of precision and to define the threshold between stage 1 and stage 2 (severe) hypertension as the 95th centile +12 mm Hg. This allowed the production of single colour-coded charts for systolic and diastolic BP and to advise on making simple adjustments for the impact of stature on individual children's results.

CONCLUSIONS

A simplified, integrated BP chart with colour-coded diagnostic thresholds was produced to assist the prompt diagnosis of hypertension in prepubertal children. This information could be included into a Paediatric Early Warning System score.

Conflicting Effects of Fetal Growth Restriction on Blood Pressure Between Human and Rat Offspring: A Meta-Analysis

Low birth weight is associated with hypertension. Low birth weight can result from fetal growth restriction (FGR) or prematurity. FGR is postulated to impact blood pressure (BP) by developmental programming. This systematic review and meta-analysis studies BP in human and animal offspring following FGR. Pubmed and Web of Science were searched for studies reporting on BP after placental insufficiency induced FGR compared with normal growth controls. Primary outcome was mean absolute BP difference (ΔBP mm Hg [95% CI]). Meta-analysis was performed using random-effects models. Subgroup analyses were executed on species, sex, age, pregnancy duration, and stress during BP readings. Due to large interspecies heterogeneity, analyses were performed separately for human (n=41) and animal (n=31) studies, the latter restricted to rats (n=27). Human studies showed a ΔBP between FGR and controls of -0.6 mm Hg ([95% CI, -1.7 to 0.6]; I²=91%). Mean ΔBP was -2.6 mm Hg (95% CI, -5.7 to 0.4) in women versus -0.5 mm Hg (95% CI, -3.7 to 2.7) in men. Subgroup analyses did not indicate age, gestational age, and stress during measurements as sources of heterogeneity. In rats, mean BP was 12.0 mm Hg ([95% CI, 8.8-15.2]; I²=81%) higher in FGR offspring. This difference was more pronounced in FGR males (13.6 mm Hg [95% CI, 10.3-17.0] versus 9.1 mm Hg [95% CI, 5.3-12.8]). Subgroup analyses on age showed no statistical interaction. BP readings under restrained conditions resulted in larger BP differences between FGR and control rats (15.3 mm Hg [95% CI, 11.6-18.9] versus 5.7 mm Hg [95% CI, 1.1-10.3]). Rat studies confirm the relation between FGR and offspring BP, while observational studies in humans do not show such differences. This may be due to the observational nature of human studies, methodological limitations, or an absence of this phenomenon in humans. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: CRD42018091819.

Neonatal hypertension

Neonatal hypertension (HT) is a frequently under reported condition and is seen uncommonly in the intensive care unit. Neonatal HT has defined arbitrarily as blood pressure more than 2 standard deviations above the base as per the age or defined as systolic BP more than 95% for infants of similar size, gestational age and postnatal age. It has been diagnosed long back but still is the least studied field in neonatology. There is still lack of universally accepted normotensive data for neonates as per gestational age, weight and post-natal age. Neonatal HT is an important morbidity that needs timely detection and appropriate management, as it can lead to devastating short-term effect on various organs and also poor long-term adverse outcomes. There is no consensus yet about the treatment guidelines and majority of treatment protocols are based on the expert opinion. Neonate with HT should be evaluated in detail starting from antenatal, perinatal, post-natal history, and drug intake by neonate and mother. This review article covers multiple aspects of neonatal hypertension like definition, normotensive data, various etiologies and methods of BP measurement, clinical features, diagnosis and management.