Neonatal Hypertension

Aortoiliac arterial thrombosis and renal artery stenosis in a patient with neonatal multisystem inflammatory syndrome: a case report and review of literature

Background

Multisystem inflammatory syndrome in neonates (MIS-N) is a rare condition thought to be associated with prenatal exposure to maternal severe acute respiratory syndrome coronavirus 2 infection. This immune-mediated hyperinflammation has been described in neonates with multiorgan dysfunction, including cardiopulmonary, encephalopathy, coagulopathy, and vascular complications. However, renovascular complications in MIS-N are rare. Here, we present a case with aortoiliac arterial thrombosis and renovascular stenosis in MIS-N.

Case presentation

A 2-day-old, full-term, male neonate presented with fever, respiratory failure, hypotensive shock, and elevated inflammatory markers. He was transferred to our neonatal intensive care unit for comprehensive monitoring and treated with antibiotics for early-onset neonatal sepsis. However, his clinical condition deteriorated. His mother reported a history of severe acute respiratory syndrome coronavirus 2 infection during the late second trimester. He was diagnosed with MIS-N based on the fulfillment of the diagnostic criteria for multiorgan involvement and laboratory findings. He responded to intravenous immunoglobulin, corticosteroids, and aspirin. However, he later developed significant hypertension, which was associated with aortoiliac arterial thrombosis and right renal artery stenosis. An elevated ferritin level was observed. The ongoing inflammatory condition was considered, and corticosteroids were restarted along with treatment for documented thrombosis using enoxaparin and aspirin. After treatment, partial resolution of aortoiliac arterial thrombus was observed. However, narrowing of the proximal part of right renal artery persisted, and blood pressure remained difficult to control, requiring multiple antihypertensive agents. Finally, the patient underwent percutaneous transluminal balloon angioplasty to control hypertension.

Conclusion

Our case revealed the clinical course of MIS-N with renovascular complications. The condition's hyperinflammatory state may have played a pathophysiological role in the development of this life-threatening complication. Although there is an increased risk of bleeding in MIS-N, thromboprophylaxis should be considered in high-risk patients. An early multidisciplinary approach is recommended to ensure prompt diagnosis and improve outcomes.

Advocating for the inclusion of kidney health outcomes in neonatal research: best practice recommendations by the Neonatal Kidney Collaborative

Acute kidney injury (AKI) occurs in nearly 30% of sick neonates. Chronic kidney disease (CKD) can be detected in certain populations of sick neonates as early as 2 years. AKI is often part of a multisystem syndrome that negatively impacts developing organs resulting in short- and long-term pulmonary, neurodevelopmental, and cardiovascular morbidities. It is critical to incorporate kidney-related data into neonatal clinical trials in a uniform manner to better understand how neonatal AKI or CKD could affect an outcome of interest. Here, we provide expert opinion recommendations and rationales to support the inclusion of short- and long-term neonatal kidney outcomes using a tiered approach based on study design: (1) observational studies (prospective or retrospective) limited to data available within a center's standard practice, (2) observational studies involving prospective data collection where prespecified kidney outcomes are included in the design, (3) interventional studies with non-nephrotoxic agents, and (4) interventional studies with known nephrotoxic agents. We also provide recommendations for biospecimen collection to facilitate ancillary kidney specific research initiatives. This approach balances the costs of AKI and CKD ascertainment with knowledge gained. We advocate that kidney outcomes be included routinely in neonatal clinical study design. Consistent incorporation of kidney outcomes across studies will increase our knowledge of neonatal morbidity.

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.

Oral sodium supplementation on growth and hypertension in preterm infants: an observational cohort study

OBJECTIVE

To evaluate the association between enteral sodium supplementation on growth and hypertension (HTN) in preterm infants.

STUDY DESIGN

A retrospective cohort study of infants born between 22-32 weeks and weighing 450-1500 grams (N = 821). Enteral sodium supplementation amounts, systolic blood pressures (SBP), weight gain, and other infant and maternal risk factors for HTN were electronically extracted.

RESULTS

Infants receiving sodium supplementation were smaller and less mature. Sodium supplementation improved serum sodium levels, weight gain, and head circumference growth without causing hypernatremia. There was no correlation between urine and serum sodium or urine sodium and weight gain. Although infants receiving sodium had higher average SBP and rates of HTN, analysis demonstrated sodium supplementation did not increase odds of hypertension (ORADJ 1.02;0.64-1.64). Postnatal steroids were associated with HTN.

CONCLUSIONS

In preterm infants with poor weight gain, enteral sodium supplementation improved growth without increasing hypertension or hypernatremia.

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.