Nicardipine for the Treatment of Neonatal Hypertension During Extracorporeal Membrane Oxygenation

Nicardipine or Nitroprusside for Postoperative Blood Pressure Control in Infants After Surgery for Congenital Heart Disease: Single-Center Retrospective Noninferiority and Cost Analysis, 2016-2020

OBJECTIVES

Postoperative hypertension frequently occurs after surgery for congenital heart disease. Given safety concerns when using calcium channel blockers in infants along with the cost and side-effect profile of nitroprusside, we retrospectively assessed our experience of using nicardipine and nitroprusside for postoperative blood pressure control in infants who underwent surgery for congenital heart disease. We also investigated the cost difference between the medications.

DESIGN

This study was a single-center retrospective, pre-post chart review of patients who had surgery for congenital heart disease between 2016 and 2020. The primary aim was a noninferiority comparison of achievement of blood pressure goal at 1-hour post-initiation of an antihypertensive agent. Secondary comparisons included achievement of blood pressure goal at 2 hours after medication initiation, Vasoactive-Inotropic Score (VIS), and blood transfusion, crystalloid volume, and calcium needs.

SETTING

Academic quaternary-care center.

PATIENTS

Infants under 1 year old who required treatment for hypertension with nitroprusside ( n = 71) or nicardipine ( n = 52) within 24 hours of surgery for congenital heart disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We failed to identify any difference in proportion of patients that achieved blood pressure control at 1-hour after medication initiation (nitroprusside 52% vs. nicardipine 54%; p = 0.86), with nicardipine noninferior to nitroprusside within a 15% margin. Of patients who did not achieve control at 1-hour post-medication initiation, receiving nicardipine was associated with blood pressure control at 2 hours post-medication initiation (79% vs. 38%; p = 0.003). We also failed to identify an association between antihypertensive types and mean VIS scores, blood transfusion volumes, crystalloid volumes, and quantities of calcium administered. Index cost of using nitroprusside was 16 times higher than using nicardipine, primarily due to difference in wholesale cost.

CONCLUSIONS

In our experience of achieving blood pressure control in infants after surgery for congenital heart disease (2016-2020), antihypertensive treatment with nicardipine was noninferior to nitroprusside. Furthermore, nicardipine use was significantly less expensive than nitroprusside. Our contemporary practice is therefore to use nicardipine in preference to nitroprusside.

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.

Neonatal hypertension: concerns within and beyond the neonatal intensive care unit

Neonatal hypertension occurs in 1%-2% of neonates in the neonatal intensive care unit (NICU) although may be underdiagnosed. Blood pressure values in premature neonates change rapidly in the first days and weeks of life which may make it more difficult to recognize abnormal blood pressure values. In addition, the proper blood pressure measurement technique must be used to ensure the accuracy of the measured values as most blood pressure devices are not manufactured specifically for this population. In premature neonates, the cause of the hypertension is most commonly related to prematurity-associated complications or management while in term neonates is more likely to be due to an underlying condition. Both oral and intravenous antihypertensive medications can be used in neonates to treat high blood pressure although none are approved for use in this population by regulatory agencies. The natural history of most neonatal hypertension is that it resolves over the first year or two of life. Of concern are the various neonatal risk factors for later cardiovascular and kidney disease that are present in most NICU graduates. Prematurity increases the risk of adulthood hypertension while intrauterine growth restriction may even lead to hypertension during childhood. From neonates through to adulthood NICU graduates, this review will cover each of these topics in more detail and highlight the aspects of blood pressure management that are established while also highlighting where knowledge gaps exist.

PICU Pharmacology

The care of the critically-ill child often includes medications used to optimize organ function, treat infections, and provide comfort. Pediatric pharmacology has some key differences that should be leveraged for safe pharmacologic management.

Neonatal Hypertension

Neonatal hypertension is uncommon but is becoming increasingly recognized. Normative blood pressure data are limited, as is research regarding the risks, treatment, and long-term outcomes. Therefore, there are no clinical practice guidelines and management is based on clinical judgment and expert opinion. Recognition of neonatal hypertension requires proper blood pressure measurement technique. When hypertension is present there should be a thorough clinical, laboratory, and imaging evaluation to promptly diagnose causes needing medical or surgical management. This review provides a practical overview for the practicing clinician regarding the identification, evaluation, and management of neonatal hypertension.

Systemic Hypertension in Pediatric Veno-Venous Extracorporeal Membrane Oxygenation

Systemic hypertension (HTN) is a recognized complication of veno-venous (VV) extracorporeal membrane oxygenation (ECMO) in children. We sought to determine the prevalence and associated features of HTN in a retrospective cohort of children (>1 year old) supported with VV ECMO from January 2015 to July 2019 at our institution. Patient and ECMO-related characteristics were reviewed, including intensive care unit (ICU) length of stay (LOS), ECMO duration, corticosteroids and nephrotoxic medication exposure, acute kidney injury (AKI), overall fluid balance, and transfusion data. We analyzed 23 children (43% female) with a median age of 8.5 years (interquartile range [IQR] = 4-14.5). Median ICU LOS was 26 days (IQR = 15-47) with a median ECMO duration of 288 hours (IQR = 106-378) and a mortality rate of 35%. HTN was diagnosed in 87% subjects at a median of 25 ECMO hours (IQR = 9-54) of whom 55% were hypertensive >50% of their ECMO duration. AKI and fluid overload were documented in >50% of cohort. All but two subjects received at least one nephrotoxic medication, and nearly all received corticosteroids. Our data demonstrate that HTN is present in a preponderance of children supported with VV ECMO and appears within the first 3 days of cannulation. Underlying etiology is likely multifactorial.