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Fike CD, Aschner JL, Avachat C, Birnbaum AK, Sherwin CMT. Multi-dose enteral L-citrulline administration in premature infants at risk of developing pulmonary hypertension associated with bronchopulmonary dysplasia. J Perinatol 2024; 44:280-287. [PMID: 37907796 PMCID: PMC10844094 DOI: 10.1038/s41372-023-01809-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/10/2023] [Accepted: 10/18/2023] [Indexed: 11/02/2023]
Abstract
OBJECTIVE Information is needed to guide the design of randomized controlled trials (RCTs) evaluating L-citrulline therapy for premature infants with pulmonary hypertension associated with bronchopulmonary dysplasia (BPD-PH). Based on our single-dose pharmacokinetic study, we evaluated the ability of a multi-dose enteral L-citrulline strategy to achieve a target trough steady-state L-citrulline plasma concentration and its tolerability in premature infants. STUDY DESIGN Plasma L-citrulline concentrations were measured in six premature infants receiving 60 mg/kg L-citrulline every 6 h for 72 h before the first and last L-citrulline doses. L-citrulline concentrations were compared to concentration-time profiles from our previous study. RESULTS Target trough plasma L-citrulline concentrations were achieved in 2/6 subjects. No serious adverse events occurred. CONCLUSIONS Multi-dose L-citrulline was well tolerated. These results will assist in the design of phase II RCTs evaluating L-citrulline dosage strategies to achieve target plasma L-citrulline concentrations in infants at risk for BPD-PH. CLINICAL TRIALS gov ID: NCT03542812.
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Affiliation(s)
- Candice D Fike
- Department of Pediatrics, the University of Utah Health, Salt Lake City, UT, USA.
| | - Judy L Aschner
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Pediatrics, Hackensack Meridian School of Medicine, Nutley, NJ, USA
| | - Charul Avachat
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
| | - Angela K Birnbaum
- Department of Pediatrics, the University of Utah Health, Salt Lake City, UT, USA
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
| | - Catherine M T Sherwin
- Department of Pediatrics, the University of Utah Health, Salt Lake City, UT, USA
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
- Dayton Children's Hospital, Dayton, OH, USA
- Department of Pediatrics, Wright State University Boonshoft School of Medicine, Dayton, OH, USA
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Aschner J, Avachat C, Birnbaum A, Sherwin C, Fike C. Multi-dose enteral L-citrulline administration in premature infants at risk of developing pulmonary hypertension associated with bronchopulmonary dysplasia. RESEARCH SQUARE 2023:rs.3.rs-3006963. [PMID: 37333204 PMCID: PMC10275028 DOI: 10.21203/rs.3.rs-3006963/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Objective Information is needed to guide the design of randomized controlled trials (RCTs) evaluating L-citrulline as a therapy for premature infants with pulmonary hypertension associated with bronchopulmonary dysplasia (BPD-PH). Our goal was to evaluate the tolerability and ability to achieve a target steady-state L-citrulline plasma concentration in prematures treated enterally with a multi-dose L-citrulline strategy based on our single-dose pharmacokinetic study. Study Design Six prematures received 60 mg/kg of L-citrulline every 6 hours for 72 hours. Plasma L-citrulline concentrations were measured before the first and last L-citrulline doses. L-citrulline concentrations were compared to concentration-time profiles from our previous study. Results Plasma L-citrulline concentrations agreed with the simulated concentration-time profiles. No serious adverse events occurred. Conclusions Simulations based on single-doses can be used to predict target multi-dose plasma L-citrulline concentrations. These results assist the design of RCTs evaluating the safety and effectiveness of L-citrulline therapy for BPD-PH. Clinical trials.gov ID: NCT03542812.
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Fike CD, Avachat C, Birnbaum AK, Aschner JL, Sherwin CM. Pharmacokinetics of L-Citrulline in Neonates at Risk of Developing Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension. Paediatr Drugs 2023; 25:87-96. [PMID: 36316628 PMCID: PMC10039462 DOI: 10.1007/s40272-022-00542-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/02/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Options to treat pulmonary hypertension (PH) in neonates with bronchopulmonary dysplasia (BPD) are few and largely ineffective. Improving the bioavailability of nitric oxide (NO) might be an efficacious treatment for BPD-PH. When administered orally, the NO-L-arginine precursor, L-citrulline, increases NO production in children and adults, however, pharmacokinetic (PK) studies of oral L-citrulline have not been performed in infants and children. OBJECTIVES This study characterized the PK of enterally administered L-citrulline in neonates at risk of developing BPD-PH to devise a model-informed dosing strategy. METHODS AND RESULTS Ten premature neonates (≤ 28 weeks gestation) were administered a single dose of 150 mg/kg (powder form solubilized in sterile water) oral L-citrulline at 32 ± 1 weeks postmenstrual age. Due to the need to limit blood draws, time windows were used to maximize the sampling over the dosing interval by assigning neonates to one of two groups (ii) samples collected pre-dose and at 1- and 2.5-h post-dose, and (ii) pre-dose and 0.25- and 3-h post-dose. The L-arginine concentrations (µmol/L) and the L-citrulline (µmol/L) plasma concentration-time data were evaluated using non-compartmental analysis (Phoenix WinNonlin version 8.1). Optimal dosage strategies were derived using a simulation-based methodology. Simulated doses of 51.5 mg or 37.5 mg/kg given four times a day produced steady-state concentrations close to a target of 50 µmol/L. The volume of distribution (V/F) and clearance (CL/F) were 302.89 ml and 774.96 ml/h, respectively, with the drug exhibiting a half-life of 16 minutes. The AUC from the time of dosing to the time of last concentration was 1473.3 h*μmol/L, with Cmax and Tmax of 799 μmol/L and 1.55 h, respectively. CONCLUSION This is the first PK study in neonates presenting data that can be used to inform dosing strategies in future randomized controlled trials evaluating enteral L-citrulline as a potential treatment to reduce PH associated with BPD in premature neonates. REGISTRATION Clinical trials.gov Identifier: NCT03542812.
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Affiliation(s)
- Candice D Fike
- Department of Pediatrics, The University of Utah Health, Salt Lake City, UT, USA
| | - Charul Avachat
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
| | - Angela K Birnbaum
- Department of Pediatrics, The University of Utah Health, Salt Lake City, UT, USA
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
| | - Judy L Aschner
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Pediatrics, Hackensack Meridian School of Medicine, Nutley, NJ, USA
| | - Catherine M Sherwin
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA.
- Department of Pediatrics, Wright State University Boonshoft School of Medicine, Dayton, OH, USA.
- Dayton Children's Hospital, Dayton, OH, USA.
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Malloy KW, Austin ED. Pulmonary hypertension in the child with bronchopulmonary dysplasia. Pediatr Pulmonol 2021; 56:3546-3556. [PMID: 34324276 PMCID: PMC8530892 DOI: 10.1002/ppul.25602] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 01/25/2023]
Abstract
Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease of prematurity resulting from complex interactions of perinatal factors that often lead to prolonged respiratory support and increased pulmonary morbidity. There is also growing appreciation for the dysmorphic pulmonary bed characterized by vascular growth arrest and remodeling, resulting in pulmonary vascular disease and its most severe form, pulmonary hypertension (PH) in children with BPD. In this review, we comprehensively discuss the pathophysiology of PH in children with BPD, evaluate the current recommendations for screening and diagnosis of PH, discern associated comorbid conditions, and outline the current treatment options.
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Affiliation(s)
- Kelsey W Malloy
- Division of Pediatric Allergy, Immunology, and Pulmonary Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Eric D Austin
- Division of Pediatric Allergy, Immunology, and Pulmonary Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Sluiter I, van Heijst A, Haasdijk R, Kempen MBV, Boerema-de Munck A, Reiss I, Tibboel D, Rottier RJ. Reversal of pulmonary vascular remodeling in pulmonary hypertensive rats. Exp Mol Pathol 2012; 93:66-73. [PMID: 22472322 DOI: 10.1016/j.yexmp.2012.03.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 03/19/2012] [Indexed: 12/27/2022]
Abstract
Pulmonary hypertension is responsible for significant mortality and morbidity among newborns and infants. The pathology is characterized by pulmonary vascular remodeling with medial hypertrophy and adventitial thickening, leading to decreased gas exchange. Since it is unknown if these abnormalities are reversible, we analyzed these vascular changes in pulmonary hypertensive rats. Exposure of rats to hypobaric hypoxia for 4 weeks induced clinical signs of pulmonary hypertension, such as increased right ventricular systolic pressure, increased right ventricular weight and considerable pulmonary vascular remodeling. The vascular changes were associated with the expression of Non -Muscle Myosin Heavy Chain B in the pre-acinar vessels and an increased expression of alpha Smooth Muscle Actin, Smooth Muscle Myosin Heavy Chain 2 and Calponin in the intra-acinar vessels. The right ventricular systolic pressure and right ventricular weight gradually decreased after specific periods of recovery in normoxia, although this reversal did not reach baseline levels after six weeks at normoxia. However, the cellular changes in the pulmonary vasculature were completely reversed. Development of pulmonary hypertension is associated with an increase of synthetic perivascular cells in the pre-acinar arteries and an aberrant differentiation of perivascular cells in the smallest intra-acinar arteries. These cellular and structural changes in the pulmonary vasculature are completely reversible after recovery in normoxia.
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Affiliation(s)
- Ilona Sluiter
- Intensive Care and Department of Pediatric Surgery, Erasmus MC-Sophia, Dr. Molewaterplein 60, 3015 GJ Rotterdam, The Netherlands.
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Abstract
Infants of birth weight ≤2500 g are termed low birth weight (LBW). These children often have considerable morbidity from prematurity and intra-uterine growth restriction. Additionally, LBW infants have increased risk for cardiac and noncardiac congenital anomalies and may require surgery. Primary rather than palliative surgical repair of cardiac lesions has been preferred in recent years. However, LBW remains a risk factor for increased mortality and morbidity after open-heart surgery (OHS). There is a paucity of information about the anesthetic challenges presented by LBW infants undergoing OHS. This review summarizes the perioperative issues of relevance to anesthesiologists who manage these high-risk patients. Emphasis is placed on management concerns that are unique to LBW infants. Retrospective data from the authors' institution are provided for those aspects of anesthetic care that lack published studies. Successful outcome often requires substantial hospital resources and collaborative multi-disciplinary effort.
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Affiliation(s)
- Glyn D Williams
- Department of Anesthesiology, Stanford University, Lucile Packard Children’s Hospital, Stanford, CA, USA
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An HS, Bae EJ, Kim GB, Kwon BS, Beak JS, Kim EK, Kim HS, Choi JH, Noh CI, Yun YS. Pulmonary hypertension in preterm infants with bronchopulmonary dysplasia. Korean Circ J 2010; 40:131-6. [PMID: 20339498 PMCID: PMC2844979 DOI: 10.4070/kcj.2010.40.3.131] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 08/13/2009] [Accepted: 09/03/2009] [Indexed: 11/23/2022] Open
Abstract
Background and Objectives With the increasing survival of preterm infants, pulmonary hypertension (PH) related to bronchopulmonary dysplasia (BPD) has become an important complication. The aim of this study was to investigate the characteristics and outcome of PH in preterm infants with BPD and to identify the risk factors for PH. Subjects and Methods We reviewed the records of 116 preterm infants with BPD cared for at a single tertiary center between 2004 and 2008. Results Twenty-nine (25%) infants had PH >2 months after birth. PH occurred initially at a median age of 65 days (range, 7-232 days). Severe BPD, a birth weight <800 g, long-term ventilator care and oxygen supplementation, a high ventilator setting, infection, and a patent ductus arteriosus (PDA) were related to PH based on univariate analysis (p<0.05). The infants who had longer oxygen supplementation were significantly more likely to have PH (odds ratio, 18.5; 95% confidence interval, 4.1-84.6; p<0.001). PH was improved in 76% of infants after a median of 85 days (range, 20-765 days). Four infants (14%) died. The death of 3 infants was attributed to PH. Conclusion BPD was frequently complicated by PH. Although PH resolved in the majority of infants, PH in preterm infants with BPD can be fatal. Regular screening for PH and adequate management are required.
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Affiliation(s)
- Hyo Soon An
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Korea
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McMahon CJ, Penny DJ, Nelson DP, Ades AM, Al Maskary S, Speer M, Katkin J, McKenzie ED, Fraser CD, Chang AC. Preterm infants with congenital heart disease and bronchopulmonary dysplasia: postoperative course and outcome after cardiac surgery. Pediatrics 2005; 116:423-30. [PMID: 16061598 DOI: 10.1542/peds.2004-2168] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Success in treatment of premature infants has resulted in increased numbers of neonates who have bronchopulmonary dysplasia (BPD) and require surgical palliation or repair of congenital heart disease (CHD). We sought to investigate the impact of BPD on children with CHD after heart surgery. METHODS This was a retrospective, multicenter study of patients who had BPD, defined as being oxygen dependent at 28 days of age with radiographic changes, and CHD and had cardiac surgery (excluding arterial duct ligation) between January 1991 and January 2002. Forty-three infants underwent a total of 52 cardiac operations. The median gestational age at birth was 28 weeks (range: 23-35 weeks), birth weight was 1460 g (range: 431-2500 g), and age at surgery was 2.7 months (range: 1.0-11.6 months). Diagnoses included left-to-right shunts (n = 15), conotruncal abnormalities (n = 13), arch obstruction (n = 6), univentricular hearts (n = 4), semilunar valve obstruction (n = 3), Shone syndrome (n = 1), and cor triatriatum (n = 1). RESULTS Thirty-day survival was 84% with 6 early and 6 late postoperative deaths. Survival to hospital discharge was 68%. There was 50% mortality for patients with univentricular hearts and severe BPD. The median duration of preoperative ventilation was 76 days (range: 2-244 days) and of postoperative ventilation was 15 days (range: 1-141 days). The median duration of cardiac ICU stay was 7.5 days (range: 1-30 days) and of hospital stay was 115 days (range: 35-475 days). Current pulmonary status includes on room air (n = 14), O2 at home (n = 4), and ventilated at home (n = 4) or in hospital (n = 4), and 5 patients were lost to follow-up. CONCLUSIONS BPD has significant implications for children who have CHD and undergo cardiac surgery, leading to prolonged ICU and hospital stays, although most survivors are not O2 dependent. Postoperative mortality was highest among patients with univentricular hearts and severe BPD. Optimal timing of surgery and strategies to improve outcome remains to be delineated.
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Affiliation(s)
- Colin J McMahon
- Division of Pediatric Cardiology, Texas Children's Hospital, Houston, Texas, USA.
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Abstract
Pulmonary hypertension with elevated pulmonary vascular resistance is a common cardiovascular complication associated with increased morbidity and mortality in preterm infants with chronic lung disease. Injury to the developing pulmonary circulation results in structural and functional abnormalities of the pulmonary vasculature. Animal studies have demonstrated that disruption of angiogenesis may contribute to the failure of normal alveolarisation in chronic lung disease. Levels of vascular endothelial growth factor in bronchoalveolar lavage fluid are lower in infants with chronic lung disease compared to preterm controls. Supplemental oxygen is commonly used to prevent and treat pulmonary hypertension, although optimal arterial oxygen saturation levels remain uncertain. Other vasodilators such as inhaled nitric oxide appear promising, but as yet have not been evaluated in the form of randomised controlled trials. Further studies are required to investigate the long-term effectiveness of pulmonary vasodilator therapy.
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Affiliation(s)
- N V Subhedar
- Neonatal Intensive Care Unit, Liverpool Women's Hospital, Liverpool, UK.
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Allen J, Zwerdling R, Ehrenkranz R, Gaultier C, Geggel R, Greenough A, Kleinman R, Klijanowicz A, Martinez F, Ozdemir A, Panitch HB, Nickerson B, Stein MT, Tomezsko J, Van Der Anker J. Statement on the care of the child with chronic lung disease of infancy and childhood. Am J Respir Crit Care Med 2003; 168:356-96. [PMID: 12888611 DOI: 10.1164/rccm.168.3.356] [Citation(s) in RCA: 195] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
Bronchoscopy is a highly versatile technique in the context of intensive care and has many potentially valuable indications. Safety is of paramount importance and the risks in critically unstable patients are correspondingly greater than in more stable children. The main contraindication to bronchoscopy is if it will provide no useful information. The procedure is obviously more risky in children with severe hypoxia, uncontrolled bleeding diathesis, cardiac failure or severe pulmonary hypertension. Monitoring should include at least oxygen saturation, blood pressure (ideally by continuous, invasive monitoring) and preferably capnography. Indications for bronchoscopy in paediatric intensive care include endobronchial toilet, sometimes instilling recombinant human DNAase even in children who do not have cystic fibrosis; checking tube patency and position; assisting in a difficult intubation or tube change; achieving the selective intubation of a main bronchus; the diagnosis and management of ventilator-associated pneumonia or the ventilated, immunocompromised host; the assessment of lobar collapse or focal hyperinflation; airway stent assessment; assessment of stridor on extubation and the diagnosis of any associated disease. New iatrogenic complications are also likely to be discovered. The procedure is very safe if performed by experienced operators with back-up from doctors skilled in airway management and the monitoring of sick children.
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Affiliation(s)
- Andrew Bush
- Imperial School of Medicine at National Heart and Lung Institute, London, UK.
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Parker TA, Abman SH. The pulmonary circulation in bronchopulmonary dysplasia. SEMINARS IN NEONATOLOGY : SN 2003; 8:51-61. [PMID: 12667830 DOI: 10.1016/s1084-2756(02)00191-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Abnormalities of the pulmonary circulation are increasingly being recognized as a major contributor to the high morbidity and mortality of bronchopulmonary dysplasia. Historically, studies have focused on the importance of pulmonary hypertension to the pathophysiology of BPD, with the assumption that pulmonary vascular abnormalities are a secondary consequence of primary injury to the airspace. Recent studies suggest, however, that abnormalities of the pulmonary vasculature, including altered growth and structure, may directly contribute to the abnormal alveolarization that characterizes the condition. In this article, we briefly outline mechanisms of pulmonary vascular injury in infants at risk of BPD. We then focus on the recognition and management of pulmonary hypertension in these infants. Finally, we review how disordered pulmonary vascular growth may contribute to the pathogenesis of BPD and emphasize the importance of the reciprocal development of the airspace and the pulmonary circulation.
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Affiliation(s)
- Thomas A Parker
- Pediatric Heart Lung Center, University of Colorado School of Medicine, 80206, Denver, CO, USA.
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Talmaciu I, Ren CL, Kolb SM, Hickey E, Panitch HB. Pulmonary function in technology-dependent children 2 years and older with bronchopulmonary dysplasia. Pediatr Pulmonol 2002; 33:181-8. [PMID: 11836797 DOI: 10.1002/ppul.10068] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Somatic and pulmonary growth coincide with resolution of hypoxemia by 2 years of age in most children with bronchopulmonary dysplasia (BPD). However, a distinct subgroup of children with BPD continue to require mechanical ventilation and/or supplemental oxygen beyond 2 years of age. This study tested the hypothesis that indices of pulmonary function would be significantly worse in children with BPD 2 years and older who remained technology-dependent secondary to hypoxemia, compared to those of age-matched children with BPD who were normoxemic. We measured pulmonary mechanics in 21 oxygen- or ventilator-dependent children with BPD 2 years and older (BPDO2 group; mean age+/-SD, 30.2+/-6.5 months) and in 19 children with BPD who had been weaned off mechanical ventilation and supplemental oxygen for at least 6 months (control group; mean age, 30.1+/-5.5 months). Respiratory rate and tidal volume were measured after sedation with chloral hydrate, and dynamic compliance and expiratory conductance were calculated using the esophageal catheter technique. Maximal flow at FRC (V'(maxFRC)) and ratio of forced-to-tidal flows at midtidal volume were obtained by the rapid thoracic compression technique. FRC was determined by nitrogen washout. There were no statistically significant differences in most measured indices of pulmonary mechanics between the BPDO2 and control groups. However, V'(maxFRC)/FRC was higher in controls compared to subjects in the BPDO2 group (0.81+/-0.40 sec(-1) vs. 0.34+/-0.21 sec(-1), P<0.003). We conclude that most indices of pulmonary function in children with BPD 2 years and older do not reflect the need for mechanical ventilation or supplemental oxygen. We speculate that measurements of lung elastic recoil and tests of distribution of ventilation and pulmonary perfusion may be more sensitive in differentiating normoxemic and hypoxemic children with BPD 2 years and older.
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Affiliation(s)
- Isaac Talmaciu
- Division of Pediatric Pulmonology, St. Christopher's Hospital for Children, Philadelphia, Pennsylvania, USA.
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Abstract
Although much has been learned about BPD in the 25 years since its initial description, BPD remains a significant complication of prematurity. Substantial advances into the understanding of its pathophysiology and pathogenesis have been made and are reflected in new therapeutic interventions. Much current research is directed towards the role of prevention, exploring new approaches for accelerating lung maturation with combined maternal steroid and thyrotropin releasing hormone (TRH) therapy, surfactant replacement therapy, high frequency oscillatory ventilation, antioxidant administration, manipulation of endogenous antioxidants, and other pharmacologic strategies to minimize lung injury. The impact of other technologies, such as synchronized intermittent mandatory ventilation, perfluorocarbon (liquid) ventilation, and perhaps inhaled nitric oxide therapy may become additional parts of the clinical regimen for some cases of severe neonatal respiratory failure. Less information is available on mechanisms which can hasten lung healing. Ongoing studies of inflammatory products, growth factors, and cytokines may lead to new therapies which will favorably influence the fibroproliferative phase of disease. In the meantime, the medical and social impact of BPD continues to remain a significant problem not only during infancy but also throughout life. Mildred Stahlman, MD, recently wrote that (a)s sanguine as the future looks for surfactant therapy, it may leave us with more very low-birth weight infants who survive, whose potential for normal pulmonary growth and development is unknown, and whose very immature organ systems, besides the lung, are still susceptible to metabolic, neurologic, and other problems. As more survivors are reaching young adulthood, respiratory and neurodevelopmental complications persist. Thus, as advances in the care of the premature newborn with respiratory distress have dramatically improved survival, the management of chronic lung disease and related problems remains a continuing challenge.
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Affiliation(s)
- S H Abman
- Department of Pediatrics, University of Colorado School of Medicine, Denver
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Abstract
Neonatologists are increasingly exploring the airways with rigid and flexible bronchoscopes. Each instrument has particular advantages; the rigid endoscope mainly for therapy, including balloon dilatation of acquired strictures, and the fibrescope mainly for inspection of the airway for diagnostic purposes. Before using either technique, it is essential to ensure that the information will be really useful and cannot be obtained using less invasive methods.
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Affiliation(s)
- A Bush
- Department of Paediatrics, Royal Brompton Hospital, London, U.K
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Bush A, Busst CM, Knight WB, Hislop AA, Haworth SG, Shinebourne EA. Changes in pulmonary circulation in severe bronchopulmonary dysplasia. Arch Dis Child 1990; 65:739-45. [PMID: 2117421 PMCID: PMC1792458 DOI: 10.1136/adc.65.7.739] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Eight patients with severe bronchopulmonary dysplasia underwent cardiac catheterisation. Seven had a pulmonary vascular resistance greater than 3 mm Hg.l-1 min.m2 (mean 8.9, range 2.2-13.8). All had raised intrapulmonary shunts (mean 25.6%, range 5.4-50%, normal less than 5%). Two had a high alveolar dead space, and two had unsuspected congenital heart disease. Epoprostenol (prostacyclin), but not 100% oxygen, caused a significant fall in pulmonary vascular resistance. Death was associated with a high pulmonary vascular resistance and a high shunt. Morphometric studies in three cases showed normal numbers of airways, but increased thickness of bronchial muscle. The numbers of alveoli were reduced and the walls thickened. There was increased medial thickness in small pulmonary arteries with distal extension of muscle. In the oldest child some vessels were obliterated by fibrosis. We speculate that measurements of pulmonary vascular resistance and shunt may have prognostic value; that a trial of pulmonary vasodilators other than oxygen might be worthwhile in patients with poor prognosis; and that abnormalities of the pulmonary circulation contribute to the difficulties of managing patients with bronchopulmonary dysplasia.
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Affiliation(s)
- A Bush
- Brompton Hospital, London
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