Pediatric pulmonary hypertension (PH) can be difficult to spot, and a lack of research on this rare condition has resulted in a lack of evidence-based diagnosis and treatment guidance–until now. The American Heart Association and the American Thoracic Society have released new, extensive guidelines that task force members hope will pave the way for new research and continued development of care plans for pediatric PH patients.
Pulmonary hypertension is a relatively rare, yet serious condition that can affect neonates, infants, and children, but is not well understood or researched. For the first time ever, a group of expert clinicians has drafted extensive guidance for diagnosing, classifying, and managing this condition in pediatric patients.
“It’s the first time people have gotten together from a variety of disciplines to try to express a starting point for how to manage kids with pulmonary hypertension,” says Steve Abman, MD, co-chair of the task force that created the guidance, director of the Pediatric Heart Lung Center, co-director of the Pediatric Pulmonary Hypertension Program, and director of the Ventilator Care Program at Children’s Hospital Colorado.
Children with PH can be found across a wide spectrum of clinical settings, but their cases have not been adequately explored, Abman says. As a result, he says, there is little background or consensus on best practices for treating and managing these conditions, and the patients suffer from poor outcomes.
Pulmonary hypertension is associated with cardiac, pulmonary, and systemic diseases in neonates, infants, and children that can lead to significant illness or even death. It affects roughly 2 in 1000 children and, although many more adults suffer from the same condition, pediatric PH is very different than in adults and traditional therapies have not yielded positive long-term outcomes in children.
"Pediatric PH is distinct from adult PH in several ways," the task force writes. "Most important, pediatric PH is intrinsically linked to issues of lung growth and development, including many prenatal and early postnatal influences. The development of PH in the neonate and young infant is often related to impaired functional and structural adaptation of the pulmonary circulation during transition from fetal to postnatal life."
In this report, a panel of experienced clinicians and clinician-scientists reviewed current literature to make recommendations on the diagnosis, evaluation, and treatment of pediatric PH. The guidance includes specific recommendations that have earned approval from both the American Heart Association and the American Thoracic Society.
Pediatric pulmonary hypertension is defined as a resting mean pulmonary artery pressure of 25 mmHg or greater in the first few months of life. It involves blockages in the pulmonary arteries, making it more difficult for the right ventricle of the heart to pump and circulate blood throughout the body and resulting in symptoms such as shortness of breath and cyanosis.
Pulmonary hypertension in children can be difficult to recognize because it’s a subtle diagnosis, Abman says. It can present as heart or lung disease, and echocardiograms-used to confirm diagnosis-are often not included in initial evaluations, he adds.
It is important to know the risk factors for pediatric PH, and to not make assumptions in children in those categories. Risk factors can include prematurity, trauma during or immediately after delivery, Down Syndrome, or unexplained cyanosis or hypoxia.
“In any child who has known risk factors, physicians should not assume its simply asthma or a viral infection, but rather to be concerned it could be a sign of early PH,” Abman says.
Early diagnosis and intervention is key, Abman says, and pediatricians should quickly make referrals, and keep in touch with specialist teams working with the child moving forward.
“If you are following a child who has PH, work closely with the team and work together to make sure that they are monitored very closely, change medication as needed, and make sure not missing any underlying causes,” Abman says.
Recommendations offered within the guidance include obtaining a comprehensive history and physical; a formal cardiac assessment; and imaging to diagnose pulmonary thromboembolic disease, peripheral pulmonary artery stenosis, pulmonary vein stenosis, pulmonary venoocclusive disease (PVOD), and parenchymal lung disease. An initial series of, and frequent follow-up, echocardiograms are also recommended, according to the report.
In non-critically ill patients, cardiac catheterization will also have to be performed before pulmonary artery hypertension (PAH)-targeted therapy is initiated, and catheterization should include acute vasoreactivity testing, and be repeated 3 to 12 months after initial therapy begins to evaluate response or clinical worsening. Physicians should also measure brain natriuretic peptide (BNP) or N-terminal proBNP at diagnosis, perform the 6-minute walk distance test to determine exercise tolerance, and complete a sleep study for patients with sleep-disordered breathing or in patients with poor responsiveness to PAH-targeted therapies.
The task force also recommends genetic testing for first-degree relatives of patients with heritable PAH, and families of patients with genetic syndromes associated with PH should be educated on symptoms that may arise to indicate development of PH.
Pediatric PH can exist as an isolated condition, or in conjunction with other heart and lung disorders, according to the report, and the guidance addresses techniques for managing the condition in a variety of circumstances.
In persistent PH of the newborn, the task force recommends using inhaled nitric acid (iNO) to reduce the need for extracorporeal membrane oxygenation. In patients with bronchopulmonary dysplasia, PAH targeted therapy and iNO are both useful.
Other pharmacologic therapies for PH include supportive care with digitalis and diuretic therapy, as well as long-term anticoagulation therapy. Warfarin may be used in patients with idiopathic PAH/heritable PAH, low cardiac output, long term indwelling catheters, and hypercoagulable states with the goal of an international normalized ratio between 1.5 and 2.0. Oxygen therapy in children with peripheral capillary oxygen saturation levels below 92% should also be used, according to the task force.
Additional medications may include calcium channel blockers, oral PAH-targeted therapy, and intravenous and subcutaneous PGI2 or its analogs for patients with higher-risk PAH.
In children with idiopathic PAH, lung biopsy may be considered, as well as a referral to a lung transplantation center for evaluation in cases of confirmed pulmonary capillary hemangiomatosis or PVOD.
In the outpatient setting, children with PH should be evaluated by specialized, multidisciplinary teams, with follow-ups at 3- to 6-month intervals, and increased frequency with advanced disease or as therapy regimens change. In terms of preventive care, children with PH should be immunized for respiratory syncytial virus prophylaxis, and receive influenza and pneumococcal vaccinations. The task force also recommends the use of supplemental oxygen while flying for children with PH, and says PH patients with syncope should avoid dehydration and strenuous exertion, as well as competitive sports.
Detailed recommendations can be found in the task force’s report for a number of other considerations in PH, including autoimmune disease, infectious disease, high altitudes, and more. Perhaps the most exciting aspect of this undertaking, however, was the identification of new goals in the diagnosis and treatment of pediatric PH, Abman says. He explains that he hopes the report will offer guidance for physicians who encounter PH patients, but also that the recommendations continue to be challenged and built upon, and that additional questions be answered through continued research.