Progress in the diagnosis and management of pulmonary hypertension in children

Bronchopulmonary dysplasia in adults: Exploring pathogenesis and phenotype

This review highlights both the longstanding impact of bronchopulmonary dysplasia (BPD) on the health of adult survivors of prematurity and the pressing need for prospective, longitudinal studies of this population. Conservatively, there are an estimated 1,000,000 survivors of BPD in the United States alone. Unfortunately, most of the available literature regarding outcomes of lung disease due to prematurity naturally focuses on pediatric patients in early or middle childhood, and the relative amount of literature on adult survivors is scant. As the number of adult survivors of BPD continues to increase, it is essential that both adult and pediatric pulmonologists have a comprehensive understanding of the pathophysiology and underlying disease process, including the molecular signaling pathways and pro-inflammatory modulators that contribute to the pathogenesis of BPD. We summarize the most common presenting symptoms for adults with BPD and identify the critical challenges adult pulmonologists face in managing the care of survivors of prematurity. Specifically, these challenges include the wide variability of the clinical presentation of adult patients, comorbid cardiopulmonary complications, and the paucity of longitudinal data available on these patients. Adult survivors of BPD have even required lung transplantation, indicating the high burden of morbidity that can result from premature birth and subsequent lung injury. In addition, we analyze the disparate symptoms and management approach to adults with "old" BPD versus "new" BPD. The aim of this review is to assist pulmonologists in understanding the underlying pathophysiology of BPD and to improve clinical recognition of this increasingly common pulmonary disease.

Right ventricular myocardial performance index (Tei) in premature infants

OBJECTIVE

The objective of this study was to evaluate the right ventricular myocardial performance index) based on echocardiography in very low birth weight premature neonates, close to hospital discharge.

METHODS

This was a prospective cross-sectional study that included premature neonates with birth weight <1,500 g and gestational age <37 weeks at the Intermediate Neonatal Unit of Bonsucesso Federal Hospital from July 2005 to July 2006. The infants underwent two-dimensional color Doppler echocardiography, being the right ventricular myocardial performance index evaluated close to hospital discharge. We compared the neonatal and echocardiographic variables in neonates with and without bronchopulmonary dysplasia.

RESULTS

A total of 81 exams were analyzed. The mean birth (standard deviation) weight and gestational age were 1,140 (235) g and 30 (2.2) weeks, respectively. The incidence of bronchopulmonary dysplasia was 32%. The mean right ventricle myocardial performance index (standard deviation) of the sample was 0.13 (0.06). We found a significant difference in aortic diameter [non-bronchopulmonary dysplasia 0.79 (0.07) vs. bronchopulmonary dysplasia 0.87 (0.11) cm, p=0.003], left ventricle in diastole [non-bronchopulmonary dysplasia 1.4 (0.19) vs. bronchopulmonary dysplasia 1.59 (0.21) cm, p=0.0006], ventricular septal thickness [non-bronchopulmonary dysplasia 0.23 (0.03) vs. bronchopulmonary dysplasia 0.26 (0.05) cm, p=0.032], and "a" measurement [(= sum of the isovolumetric contraction time, ejection time, and isovolumetric relaxation time) when calculating the myocardial performance index (p=0.01)].

CONCLUSION

Higher "a" interval in neonates with bronchopulmonary dysplasia suggests right ventricle diastolic dysfunction. We conclude that the right ventricle myocardial performance index is an important indicator both of ventricular function and for serial follow-up testing of very low birth weight premature neonates, especially those with bronchopulmonary dysplasia.

Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment

Pediatric pulmonary hypertension (PPH) is a multifactorial disease with diverse etiologies and presenting features. Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is the presenting feature for several pulmonary vascular diseases. It is often a hidden component of other lung diseases, such as cystic fibrosis and bronchopulmonary dysplasia. Alterations in lung development and genetic conditions are an important contributor to pediatric pulmonary hypertensive disease, which is a distinct entity from adult PH. Many of the causes of pediatric PH have prenatal onset with altered lung development due to maternal and fetal conditions. Since lung growth is altered in several conditions that lead to PPH, therapy for PPH includes both pulmonary vasodilators and strategies to restore lung growth. These strategies include optimal alveolar recruitment, maintaining physiologic blood gas tension, nutritional support, and addressing contributing factors, such as airway disease and gastroesophageal reflux. The outcome for infants and children with PH is highly variable and largely dependent on the underlying cause. The best outcomes are for neonates with persistent pulmonary hypertension (PPHN) and reversible lung diseases, while some genetic conditions such as alveolar capillary dysplasia are lethal. © 2021 American Physiological Society. Compr Physiol 11:2135-2190, 2021.

Prevalence of Pulmonary Hypertension in Pediatric Patients With Obstructive Sleep Apnea and a Cardiology Evaluation: A Retrospective Analysis

STUDY OBJECTIVES

Pulmonary hypertension (PH) has been reported as a serious complication of obstructive sleep apnea (OSA) in children; however, estimated prevalence rates vary widely (zero to 85%). The purpose of this study is to determine the prevalence of PH in children with OSA and identify factors that may predict an increased PH risk in children with OSA.

METHODS

A retrospective review of all pediatric beneficiaries (88,058) in the San Antonio Military Health System with a diagnosis of OSA and a clinical evaluation by a pediatric cardiologist. OSA severity and nadir oxygen saturation were recorded from overnight polysomnography. Reason for referral, comorbid disorders, echocardiogram results, and cardiac diagnoses were obtained from cardiology records.

RESULTS

OSA was identified in 2,020 pediatric patients (2.3%). A pediatric cardiology consultation was reported for 296 patients with OSA. After excluding 95 patients for incorrect OSA diagnoses, incomplete data, or OSA treatment before cardiology evaluation, 163 patients were included in the final analysis. A diagnosis of PH was found in 3 patients with OSA (1.8%). Two of these patients had obesity, and all three had comorbid cardiac disorders.

CONCLUSIONS

Prevalence of PH in pediatric patients with OSA is low and none of the patients with PH had severe OSA. Current guidelines recommend PH screening in patients with severe OSA, yet OSA severity may not accurately predict risk. Factors evaluated in this study did not demonstrate an increased PH risk; additional research is necessary to improve screening in pediatric patients with OSA.

CITATION

Burns AT, Hansen SL, Turner ZS, Aden JK, Black AB, Hsu DP. Prevalence of pulmonary hypertension in pediatric patients with obstructive sleep apnea and a cardiology evaluation: a retrospective analysis. J Clin Sleep Med. 2019;15(8):1081-1087.

Phenotypes of Bronchopulmonary Dysplasia in Adults

Bronchopulmonary dysplasia (BPD), first described by Northway in 1967, is a process of neonatal lung injury that is most strongly associated with prematurity. The "old" form of the disease associated with the oxidative damage and volutrauma from perinatal mechanical ventilation has been increasingly supplanted by a "new" form resulting from interrupted growth of the lung at earlier stages of fetal development. Given the significant improvement in the survival of children with BPD since the 1980s, many more of these patients are living into adulthood and are being seen in adult pulmonary practices. In this review, we present three brief vignettes of patients from our practice to introduce three of the major patterns of disease seen in adult survivors of BPD, namely, asthma-like disease, obstructive lung disease, and pulmonary hypertension. Additional factors shown to affect the lives of adult BPD survivors are also discussed. Finally, we discuss insights into the process of transitioning these complex patients from pediatric to adult pulmonary practices. As survivors of BPD enter adulthood and continue to require specialty pulmonary care, awareness of the disease's varied manifestations and responses to treatment will become increasingly important.

Development and construct validation of a parent-proxy quality of life instrument in children with bronchopulmonary dysplasia aged 4-8 years old

PURPOSE

Children with bronchopulmonary dysplasia often develop complications that affect them well into adult life. Very little is known about how this affects their quality of life, since no sensitive instrument is available to measure health-related quality of life in this population. In this study, a Dutch parent-proxy instrument was developed for this purpose.

METHODS

A list of items was generated after literature search and interviews with both parents of patients and clinical experts. Clinically relevant items were selected with the clinical impact method and item analysis. Results of clinical tests to measure complications in children with bronchopulmonary dysplasia were correlated with these items to select the items that show construct validity. Cronbach's alpha was calculated to estimate internal consistency of the items in the final questionnaire.

RESULTS

In total, 92 children and their parents and 7 clinicians participated. Of 130 identified items, 47 showed clinical relevance. Spirometry, the Child Behavior Checklist, mean arterial pressure, and body mass index were used to determine construct validity of 33 items. These items were structured within five domains: pulmonary complaints, school functioning, growth and nutrition, exercise and locomotion, emotional functioning and health care concerns. The questionnaire showed excellent internal consistency with Cronbach's alpha of 0.919.

CONCLUSION

This study developed a disease-specific parent-proxy instrument to measure health-related quality of life in children with bronchopulmonary dysplasia aged 4-8 years old, the BPD-QoL. All included items show construct validity and internal consistency reliability. Future research should focus on further validation and analysis of responsiveness and reliability.

Useful pharmacodynamic endpoints in children: selection, measurement, and next steps

Pharmacodynamic (PD) endpoints are essential for establishing the benefit-to-risk ratio for therapeutic interventions in children and neonates. This article discusses the selection of an appropriate measure of response, the PD endpoint, which is a critical methodological step in designing pediatric efficacy and safety studies. We provide an overview of existing guidance on the choice of PD endpoints in pediatric clinical research. We identified several considerations relevant to the selection and measurement of PD endpoints in pediatric clinical trials, including the use of biomarkers, modeling, compliance, scoring systems, and validated measurement tools. To be useful, PD endpoints in children need to be clinically relevant, responsive to both treatment and/or disease progression, reproducible, and reliable. In most pediatric disease areas, this requires significant validation efforts. We propose a minimal set of criteria for useful PD endpoint selection and measurement. We conclude that, given the current heterogeneity of pediatric PD endpoint definitions and measurements, both across and within defined disease areas, there is an acute need for internationally agreed, validated, and condition-specific pediatric PD endpoints that consider the needs of all stakeholders, including healthcare providers, policy makers, patients, and families.

A Computable Phenotype Improves Cohort Ascertainment in a Pediatric Pulmonary Hypertension Registry

OBJECTIVES

To compare registry and electronic health record (EHR) data mining approaches for cohort ascertainment in patients with pediatric pulmonary hypertension (PH) in an effort to overcome some of the limitations of registry enrollment alone in identifying patients with particular disease phenotypes.

STUDY DESIGN

This study was a single-center retrospective analysis of EHR and registry data at Boston Children's Hospital. The local Informatics for Integrating Biology and the Bedside (i2b2) data warehouse was queried for billing codes, prescriptions, and narrative data related to pediatric PH. Computable phenotype algorithms were developed by fitting penalized logistic regression models to a physician-annotated training set. Algorithms were applied to a candidate patient cohort, and performance was evaluated using a separate set of 136 records and 179 registry patients. We compared clinical and demographic characteristics of patients identified by computable phenotype and the registry.

RESULTS

The computable phenotype had an area under the receiver operating characteristics curve of 90% (95% CI, 85%-95%), a positive predictive value of 85% (95% CI, 77%-93%), and identified 413 patients (an additional 231%) with pediatric PH who were not enrolled in the registry. Patients identified by the computable phenotype were clinically distinct from registry patients, with a greater prevalence of diagnoses related to perinatal distress and left heart disease.

CONCLUSIONS

Mining of EHRs using computable phenotypes identified a large cohort of patients not recruited using a classic registry. Fusion of EHR and registry data can improve cohort ascertainment for the study of rare diseases.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02249923.

Trends in Hospitalization for Pediatric Pulmonary Hypertension

BACKGROUND AND OBJECTIVES

Pulmonary hypertension (PH) has been associated with substantial morbidity and mortality in children, but existing analyses of inpatient care are limited to small single-institution series or focused registries representative of selected patient subgroups. We examined US national data on pediatric PH hospitalizations to determine trends in volume, demographics, procedures performed during admission, and resource utilization.

METHODS

Retrospective cohort study using a national administrative database of pediatric hospital discharges: the Kids' Inpatient Database.

RESULTS

Children with PH accounted for 0.13% of the 43 million pediatric hospitalizations in the United States between 1997 and 2012, and discharges demonstrated an increasing trend over the study period (P < .0001). Cumulative, inflation-adjusted national hospital charges for PH hospitalizations rose (P = .0003) from $926 million in 1997 to $3.12 billion in 2012. Patients with PH without associated congenital heart disease (CHD) comprised an increasing and majority (56.4%) proportion over the study period (P < .0001), children without associated CHD admitted at urban teaching hospitals comprised the fastest-growing subgroup. In-hospital, all-cause mortality was high (5.9%) in children with PH, but demonstrated a decreasing trend (P < .0001).

CONCLUSIONS

Morbidity and mortality of pediatric PH continue to represent substantial and growing health care burdens. Shifts in case mix toward PH not associated with CHD, toward noncardiac procedures, and toward care in urban teaching hospitals will increase pressure to manage resource utilization in this small but growing patient group and to improve expertise and define excellence in PH care across a wide range of clinical settings.

The Post-Anesthetic Care of Pediatric Patients With Pulmonary Hypertension

Few conditions make even the most experienced pediatric anesthesiologists take pause. Pulmonary hypertension is one such condition due to the associated high perioperative morbidity and mortality. Much is written about the intraoperative management of pediatric pulmonary hypertension. This article will instead focus on postoperative care and review the evidence in support of a risk stratification approach for the post-anesthetic disposition of these patients. The total risk for post-anesthetic adverse events includes the patient's baseline risk factors and the incremental risks imposed by the procedure and anesthetic. A proposal with recommendations to guide practitioners and a table summarizing relevant factors are provided. Last, the readers' attention is drawn to the heterogeneity of pulmonary hypertensive disease. Pulmonary arterial hypertension (precapillary) differs significantly from pulmonary venous hypertension (postcapillary); the anesthetic management for one may be relatively contraindicated in the other. Their dissimilarities justify the need to distinguish them for study and research endeavors.