Neonatal Hypertension Treatment & Management

Tailor treatment decisions, which may include intravenous therapy, oral therapy, or both, to the severity of the hypertension. Hypertension resolves in most infants over time, although a small number of infants may have persistent blood pressure elevation throughout childhood.

Numerous medications are available that may be used in the treatment of neonatal hypertension. Assess the clinical status of the infant and correct any easily correctable iatrogenic causes of hypertension (eg, infusions of inotropic agents, volume overload, higher sodium intake through infusion/total parenteral nutrition (TPN), pain ^[25] ) prior to instituting drug therapy. Next, choose an antihypertensive agent that is most appropriate for the specific clinical situation. ^[26]

Few medications are approved for use in treating hypertension in neonates; therefore, all such use must be considered off label. Use caution to avoid sudden lowering of the blood pressure; watch for side effects associated with off label use.

Transfer

Occasionally, infants may need to be transferred to specialized centers for advanced diagnostic or therapeutic procedures, such as angiography or vascular surgery.

Diet

A low-sodium diet may assist in treatment of infants with persistent hypertension; however, because most infant formula is relatively low in sodium content, no special dietary modifications are usually necessary in the neonatal period.

Consultations

It is prudent to consult a pediatric cardiologist and a pediatric nephrologist before initiating extensive work up. Consultation with a cardiologist will be helpful in obtaining an echocardiography and/or evaluation of congestive heart failure and to evaluate cardiac functions. A nephrologist consultation may be needed if parenchymal renal disease is diagnosed. Consult with an interventional radiologist in conjunction with a pediatric nephrologist to obtain renal angiography studies.

Deterrence and prevention

Although several studies have examined the role of placement of umbilical artery catheters (ie, low versus high lines), no definitive proof has emerged that changes in catheter placement can prevent thromboembolism and the subsequent development of hypertension.

Usually, continuous intravenous infusions are the most appropriate initial therapy, especially in acutely ill infants with severe hypertension. ^[8] The advantages of intravenous infusions are numerous, most importantly including the ability to quickly increase or decrease the rate of infusion to achieve the desired blood pressure (BP). In patients of any age with malignant hypertension, take care to avoid too rapid a reduction in BP, in order to avoid cerebral ischemia and hemorrhage; premature infants in particular are already at an increased risk because of the immaturity of their periventricular circulation.

Because of the paucity of available data regarding the use of intravenous antihypertensive infusions in newborns, the choice of agent depends on the individual clinician's experience.

Currently available drugs for continuous infusion include sodium nitroprusside, labetalol, esmolol, fenoldopam and nicardipine (see Table 1, below). Nicardipine, which is a dihydropyridine calcium channel blocker, has been reported to be effective most often in neonates; it appears to have some advantages compared with older drugs that may make it the drug of choice in the neonatal population.

Regardless of the drug chosen, continuously monitor BP via an indwelling arterial catheter or by frequently repeated (every 10-15min) cuff readings so that the rate of infusion can be titrated to achieve the desired degree of BP control.

Table 2. Intravenous Drugs for Severe Hypertension in Neonates ^[21] (Open Table in a new window)

For some infants, intermittently administered intravenous agents have a role in therapy (see Table 1, above). Hydralazine and labetalol, in particular, may be useful in infants with mild to moderate hypertension who are not yet candidates for oral therapy because of gastrointestinal (GI) dysfunction. ^[8] Enalaprilat, the intravenous angiotensin-converting enzyme (ACE) inhibitor, has also been reported to be useful in the treatment of neonatal renovascular hypertension; however, it should be used with great caution. No study has been performed to determine a safe and effective pediatric dose; furthermore, even doses at the lower end of published ranges may lead to significant prolonged hypotension and oliguric acute renal failure.

These agents (see Table 2, below) are best reserved for infants with less severe hypertension or infants whose acute hypertension has been controlled with intravenous drugs and who are ready to be converted to long-term therapy. Although captopril had once been considered by many authorities to be the oral drug of choice for neonatal hypertension, this has come under question because of the possibility of adverse effects on renal development, particularly in premature infants. It is probably acceptable for use in infants with a postconceptual age of 44 weeks and above.

Beta-blockers may need to be avoided in long-term antihypertensive therapy in infants with bronchopulmonary dysplasia (BPD). In such infants, diuretics may have a beneficial effect not only in controlling blood pressure (BP), but also in improving pulmonary function. Other drugs that may be useful in some infants include vasodilators, such as hydralazine and minoxidil (because it can be compounded into a stable suspension), and the calcium channel blocker isradipine, which may be superior to the older agents.

Nifedipine is a poor choice for long-term therapy because of the difficulty in administering small doses and because of the rapid, profound, and short-lived drops in BP that are typically produced by this agent.

Table 3. Oral Antihypertensive Agents Useful for Treatment of Neonatal Hypertension ^[21] (Open Table in a new window)

Surgery is rarely indicated for the treatment of neonatal hypertension, except for specific diagnoses, such as ureteral obstruction, aortic coarctation, or certain tumors. Unilateral renal venous thrombosis is commonly treated with nephrectomy to avoid the need for long-term drug therapy.

For infants with renal arterial stenosis, managing the infant medically may be necessary until the patient’s growth is sufficient for the child to undergo definitive repair of the vascular abnormalities. ^[25] Infants with malignant hypertension secondary to polycystic kidney disease may require bilateral nephrectomy. Fortunately, such severely affected infants are quite rare.

Monitor blood pressure (BP) regularly in neonates with hypertension until the infant is ready for discharge from the NICU. Infants treated with angiotensin-converting enzyme (ACE) inhibitors or diuretics should have electrolyte levels and renal function monitored periodically until discharge.

Arrangements for home BP monitoring should be part of the discharge plan for any infant sent home on antihypertensive therapy. The optimal device for home BP measurements in an infant is a Dinamap device or a similar oscillometric device. A second choice is a Doppler device: however, this only measures systolic BP and is difficult to teach parents to use. Therefore, oscillometric devices should be prescribed.

Include BP measurement at all follow-up visits for infants with neonatal hypertension. In addition, monitor infants with bronchopulmonary dysplasia at discharge and those who had complicated NICU courses for the development of hypertension following discharge.

Ultrasonography should be obtained 6-12 months after discharge in infants with hypertension to ensure that the kidneys are growing normally.