Neonatal Hypertension

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.

Pharmacogenomics-based individualized treatment of hypertension in preterm infants: A case report and review of the literature

BACKGROUND

Neonatal hypertension is a rare but potentially serious condition that requires careful monitoring and treatment. Pharmacogenomics can help guide individualized drug therapy and improve outcomes.

CASE SUMMARY

We report a case of a preterm infant with multiple complications, including bronchopulmonary dysplasia (BPD), sepsis, intracranial hemorrhage, and hypertension. The infant was treated with various drugs, including dexamethasone and amlodipine. The infant was diagnosed with neonatal hypertension based on blood pressure measurements exceeding the 95th percentile for his age and sex. The possible causes of hypertension included dexamethasone, hydrochlorothiazide, spironolactone, and BPD. The infant was treated with oral amlodipine to lower his blood pressure. A pharmacogenomic test was performed to evaluate the genetic polymorphisms of ABCB1 and CYP3A5, which are involved in the metabolism and transport of dexamethasone and amlodipine. The infant's blood pressure was well controlled after the dose of amlodipine was reduced according to the pharmacogenomic results. The infant had a stable general condition and was discharged on the 100th d after birth.

CONCLUSION

This case illustrates the importance of regular blood pressure monitoring and etiological investigation in preterm infants with hypertension. Pharmacogenomics can provide useful information for individualized drug therapy and safety in this population.

Neonatal systemic hypertension across the PHIS database: An update

BACKGROUND

The definition of systemic hypertension in the neonatal population remains elusive given the variability of normative blood pressure measurements. Inadequate literature exists about incidence, therapy and long-term management of systemic hypertension in neonates. We aimed to describe the current incidence of neonatal systemic hypertension, differences in demographic and risk factors data.

METHODS

Retrospective cohort of neonates (≤28 days) admitted to a neonatal intensive care unit participating in Pediatric Health Information System (PHIS) between Jan 2010 and December 2020 with an ICD 9/10 code for hypertension. Patients were excluded if they had congenital heart disease lesions that might contribute to systemic hypertension or had incomplete data.

RESULTS

There were a total of 2494 hypertensive patients among the 432,367 NICU patients meeting the study inclusion criteria, with an incidence of 0.6%. Patients with hypertension were significantly more likely to die before discharge compared to patients without HTN (8.4% versus 3.8%, respectively, p < 0.001). Of the 2494, 52.8% received at least one antihypertensive agent, with hydralazine being the most prescribed agent (29.7%).

CONCLUSION

Diagnosis of Systemic hypertension continues to increase in the neonatal population, despite absence of well-defined criteria necessitating targeted medical management. A consensus guideline which addresses this very important condition is beneficial.

Phthalates cause a low-renin phenotype commonly found in premature infants with idiopathic neonatal hypertension

Since the 1970s, when the initial reports of neonatal hypertension related to renal artery thromboembolism were published, other secondary causes of neonatal hypertension have been reported. Those infants with no identifiable cause of hypertension were labeled with a variety of terms. Herein, we describe such infants as having idiopathic neonatal hypertension (INH). Most, but not all, of these hypertensive infants were noted to have bronchopulmonary dysplasia (BPD). More recently, reports described common clinical characteristics seen in INH patients, whether or not they had BPD. This phenotype includes low plasma renin activity, presentation near 40 weeks postmenstrual age, and a favorable response to treatment with spironolactone. A small prospective study in INH patents showed evidence of mineralocorticoid receptor activation due to inhibition of 11β-HSD2, the enzyme that converts cortisol to the less potent mineralocorticoid-cortisone. Meanwhile, phthalate metabolites have been shown to inhibit 11β-HSD2 in human microsomes. Premature infants can come in contact with exceptionally large phthalate exposures, especially those infants with BPD. This work describes a common low-renin phenotype, commonly seen in patients categorized as having INH. Further, we review the evidence that hypertension in INH patients with the low-renin phenotype may be mediated by phthalate-associated inhibition of 11β-HSD2. Lastly, we review the implications of these findings regarding identification, treatment, and prevention of the low-renin hypertension phenotype seen in premature infants categorized as having INH.