Synonyms: chronic lung disease (CLD) of prematurity, BPD
Bronchopulmonary dysplasia (BPD) is a chronic lung disease that most commonly occurs in premature infants who have needed mechanical ventilation and oxygen therapy for infant respiratory distress syndrome (RDS), but can also occur in immature infants who have had few signs of initial lung disease. Although the disorder is most often associated with premature birth, it can also occur in infants born at term who need aggressive ventilator therapy for severe, acute lung disease.
Bronchopulmonary dysplasia (BPD) has traditionally been defined as the presence of persistent respiratory signs and symptoms, the need for supplemental oxygen to treat hypoxaemia, and an abnormal chest X-ray at 36 weeks postmenstrual age (gestational age plus chronological age). The traditional definition is not specific and does not account for important clinical distinctions related to extremes of prematurity and variable criteria for the use of prolonged oxygen therapy. Some definitions use dependency on oxygen/respiratory support at 36 weeks, and some use physiological criteria. Most current definitions require the presence of the following features:
- Use of positive pressure ventilation in the first 2 weeks of life, for a minimum of 3 days.
- Clinical signs of abnormal respiratory function.
- Requirement for supplemental oxygen after the 28th day of life in order to keep PaO2 >50 mm Hg.
- Chest X-ray showing diffuse abnormalities characteristic of BPD.
The National Institute of Health (US) criteria for BPD (for neonates treated with more than 21% oxygen for at least 28 days):
- Breathing room air at 36 weeks post-menstrual age or discharge (whichever comes first) for babies born before 32 weeks, or
- breathing room air by 56 days postnatal age, or discharge (whichever comes first) for babies born after 32 weeks gestation.
- Need for <30% oxygen at 36 weeks postmenstrual age, or discharge (whichever comes first) for babies born before 32 weeks, or
- need for <30% oxygen to 56 days postnatal age, or discharge (whichever comes first).
- Need for >30% oxygen, with or without positive pressure ventilation or continuous positive pressure at 36 weeks postmenstrual age, or discharge (whichever comes first) for babies born before 32 weeks, or
- need for >30% oxygen with or without positive pressure ventilation or continuous positive pressure at 56 days postnatal age, or discharge (whichever comes first) for babies born after 32 weeks' gestation.
- The risk of bronchopulmonary dysplasia (BPD) rises with decreasing birthweight. Figures for incidence vary depending on criteria used. A recent study found that approximately half of all admissions, weighing <1,250 g, to a UK neonatal intensive care unit developed BPD.
- The incidence has changed over recent years due to policies to offer neonatal intensive care more widely to the most immature infants.
- Population-based studies show rates of BPD among surviving infants still hospitalised at 36 weeks after birth range from 13-35%.
- In the most immature infants, even minimal exposure to oxygen and mechanical ventilation can be enough to contribute to BPD.
- The overall incidence of BPD is reported at about 20% of ventilated newborns, but wide variability exists between centres, probably because of regional differences in the clinical definitions of BPD, the proportion of newborns with extreme prematurity, and specific patient management.
- Maternal cervical colonisation and/or colonisation in the neonate with Ureaplasma urealyticum have been implicated in the development of BPD.
Infants affected are usually immature and have very low birthweight.
- They respond well to initial surfactant and ventilation, but then have an increase in their oxygen and ventilatory requirements in the first 2 weeks of life.
- This dependence on respiratory support tends to worsen from week 2 to week 4.
- There is then persistent hypoxia ± difficulty with ventilator weaning.
- Usually they have tachypnoea, tachycardia and signs of respiratory distress, such as intercostal recession, grunting and nasal flaring. The infants gain weight poorly and have higher energy requirements than ventilated babies without BPD.
- Poorly responsive infant respiratory distress syndrome (RDS).
- Pulmonary atelectasis.
- Air leak syndromes (include pulmonary interstitial emphysema, pneumomediastinum, pneumothorax, pneumopericardium, pneumoperitoneum and subcutaneous emphysema).
- Patent ductus arteriosus.
- Subglottic stenosis or tracheomalacia.
- Cystic fibrosis.
- Postinfective bronchiectasis.
- Obliterative bronchiolitis.
- Typical features include hyperinflation, cyst formation, areas of atelectasis, pulmonary interstitial emphysema and pulmonary oedema.
- CXRs also help to differentiate bronchopulmonary dysplasia (BPD) from other conditions such as pneumonia or air leak syndrome.
- The diagnostic and prognostic usefulness of CXRs in BPD is highly variable.
- Arterial blood gases may show acidosis, hypercapnia and relative hypoxia (for the inspired oxygen concentration).
- Continuous oxygen monitoring by using pulse oximetry because of frequent oxygen desaturations.
- CT/MRI scans have been used to give more detailed pictures of the lung, but their routine use isn't widespread. High-resolution CT may detect abnormalities not seen on routine CXR.
- Pulmonary histology shows signs of acute lung injury and bronchiolitis with stages of exudation, proliferation and obliterative fibroproliferation.
There is little useful evidence to support most treatments or preventative measures used in bronchopulmonary dysplasia (BPD), due to the extreme difficulty of conducting useful trials in this area. Emphasis is placed on prevention of the condition by:
- Prevention of preterm birth and chorioamnionitis.
- Using early surfactant administration.
- Careful attention to optimal oxygenation, fluid management and nutritional support.
- Early extubation and increased use of continuous positive airway pressure (CPAP) rather than positive pressure ventilation where possible.
- Careful management of ventilation and weaning.
- Avoiding hyperoxia and providing expert nutritional support.
- Giving prophylactic steroids to mothers at risk of premature labour to reduce risk of infant respiratory distress syndrome (RDS).
- Furosemide and other diuretics are used to treat fluid overload and pulmonary hypertension.
- Bronchodilators (eg salbutamol) have a role in reducing airways resistance. Combined therapy with albuterol and ipratropium bromide may be more effective than either agent alone.
- Methylxanthines such as theophylline and caffeine are used to increase respiratory drive, decrease apnoea, and improve diaphragmatic contractility.
- The benefits of early postnatal corticosteroid treatment such as dexamethasone (given within the first 7 days of life) may not outweigh the adverse effects of treatment. Early corticosteroid treatment facilitates extubation and reduces the risk of chronic lung disease and patent ductus arteriosus, but causes short-term adverse effects including gastrointestinal bleeding, intestinal perforation, hyperglycaemia, hypertension, hypertrophic cardiomyopathy and growth failure.
- Corticosteroid treatment initiated after 7 days of life may reduce neonatal mortality without significantly increasing the risk of adverse long-term neurodevelopmental outcomes but current evidence is limited and so it is recommended to reserve the use of late corticosteroids to infants who cannot be weaned from mechanical ventilation and to minimise the dose and duration of any course of treatment.
- As yet there is no convincing evidence to support the use of the antioxidant superoxide dismutase.
- Inhaled nitric oxide relaxes the pulmonary vasculature and has been shown in some studies to improve long-term neurodevelopmental outcome. However the results of a number of studies are mixed and the benefits of inhaled nitric oxide are unclear. Recent studies have not shown inhaled nitric oxide to be effective in preventing BPD.
- By adolescence/early adulthood the main changes remaining are airways obstruction, airways hyper-reactivity and hyperinflation.
- There is evidence of an increased risk of emphysema.
- Increased tendency to suffer pulmonary infection, particularly respiratory syncytial virus (RSV). Some clinicians use RSV immunoglobulin or RSV monoclonal antibody injections (palivizumab) in the winter months to prevent this potentially fatal complication in bronchopulmonary dysplasia (BPD) sufferers. Recent study suggests that prophylaxis of RSV infection is cost-effective for the NHS.
- Vaccination against influenza should be considered.
- Most sufferers survive infancy, but are prone to growth delay, infections, asthma, neurological and cardiac dysfunction.
- Lung function tends to improve slowly throughout childhood, but spirometric and radiological evidence of impaired function/damage usually persists.
- The first 2 years are the 'danger' period for airways disease. Affected infants can remain oxygen-dependent for many months and frequently require hospital readmission in the first 2 years after birth.
- Infants with persistent right ventricular hypertrophy or pulmonary hypertension unresponsive to oxygen supplementation carry a worse prognosis.
- The most severely affected may remain symptomatic and have evidence of airway obstruction even as adults.
Further reading & references
- Shaw NJ, Kotecha S; Management of infants with chronic lung disease of prematurity in the United Kingdom. Early Hum Dev. 2005 Feb;81(2):165-70. Epub 2005 Jan 16.
- Baley JE, Hancharik SM, Rivers A; Observations of a support group for parents of children with severe bronchopulmonary dysplasia. J Dev Behav Pediatr. 1988 Feb;9(1):19-24.
- Cutz E, Chiasson D; Chronic lung disease after premature birth. N Engl J Med. 2008 Feb 14;358(7):743-5; author reply 745-6.
- Eichenwald EC, Stark AR; Management and outcomes of very low birth weight. N Engl J Med. 2008 Apr 17;358(16):1700-11.
- Bronchopulmonary Dysplasia Resource, Premature baby, Premature Child
- Home oxygen and Chronic Lung Disease, BLISS – the premature baby charity
- Greenough A; Long-term pulmonary outcome in the preterm infant. Neonatology. 2008;93(4):324-7. Epub 2008 Jun 5.
- Kinsella JP, Greenough A, Abman SH; Bronchopulmonary dysplasia. Lancet. 2006 Apr 29;367(9520):1421-31.
- Sahni R, Ammari A, Suri MS, et al; Is the new definition of bronchopulmonary dysplasia more useful? J Perinatol. 2005 Jan;25(1):41-6.
- Walsh MC, Yao Q, Gettner P, et al; Impact of a physiologic definition on bronchopulmonary dysplasia rates. Pediatrics. 2004 Nov;114(5):1305-11.
- Panickar J, Scholefield H, Kumar Y, et al; Atypical chronic lung disease in preterm infants. J Perinat Med. 2004;32(2):162-7.
- Manktelow BN, Draper ES, Annamalai S, et al; Factors affecting the incidence of chronic lung disease of prematurity in 1987, 1992, and 1997. Arch Dis Child Fetal Neonatal Ed. 2001 Jul;85(1):F33-5.
- Hentschel J, Berger TM, Tschopp A, et al; Population-based study of bronchopulmonary dysplasia in very low birth weight infants in Switzerland. Eur J Pediatr. 2005 May;164(5):292-7. Epub 2005 Feb 15.
- Ambalavanan N et al; Bronchopulmonary Dysplasia, eMedicine, Nov 2009
- Fitzgerald DA, Van Asperen PP, Lam AH, et al; Chest radiograph abnormalities in very low birthweight survivors of chronic neonatal lung disease. J Paediatr Child Health. 1996 Dec;32(6):491-4.
- Moya MP, Bisset GS 3rd, Auten RL Jr, et al; Reliability of CXR for the diagnosis of bronchopulmonary dysplasia. Pediatr Radiol. 2001 May;31(5):339-42.
- Van Marter LJ; Strategies for preventing bronchopulmonary dysplasia. Curr Opin Pediatr. 2005 Apr;17(2):174-80.
- Stevens TP, Harrington EW, Blennow M, et al; Early surfactant administration with brief ventilation vs. selective surfactant Cochrane Database Syst Rev. 2007 Oct 17;(4):CD003063.
- Kamlin CO, Davis PG; Long versus short inspiratory times in neonates receiving mechanical ventilation. Cochrane Database Syst Rev. 2004 Oct 18;(4):CD004503.
- Antenatal Corticosteroids to Prevent Respiratory Distress Syndrome, Royal College of Obstetricians and Gynaecologists (2004)
- Halliday HL, Ehrenkranz RA, Doyle LW; Early (< 8="" days)="" postnatal="" corticosteroids="" for="" preventing="" chronic="" lung="" disease="" in="" cochrane="" database="" syst="" rev.="" 2009="" jan="">
- Halliday HL, Ehrenkranz RA, Doyle LW; Late (>7 days) postnatal corticosteroids for chronic lung disease in preterm Cochrane Database Syst Rev. 2009 Jan 21;(1):CD001145.
- Suresh GK, Davis JM, Soll RF; Superoxide dismutase for preventing chronic lung disease in mechanically Cochrane Database Syst Rev. 2001;(1):CD001968.
- Mestan KK, Marks JD, Hecox K, et al; Neurodevelopmental outcomes of premature infants treated with inhaled nitric oxide. N Engl J Med. 2005 Jul 7;353(1):23-32.
- Mercier JC, Hummler H, Durrmeyer X, et al; Inhaled nitric oxide for prevention of bronchopulmonary dysplasia in premature Lancet. 2010 Jul 31;376(9738):346-54. Epub 2010 Jul 23.
- Wong PM, Lees AN, Louw J, et al; Emphysema in young adult survivors of moderate to severe bronchopulmonary dysplasia. Eur Respir J. 2008 Apr 2;.
- No authors listed; Palivizumab, a humanized respiratory syncytial virus monoclonal antibody, reduces hospitalization from respiratory syncytial virus infection in high-risk infants. The IMpact-RSV Study Group. Pediatrics. 1998 Sep;102(3 Pt 1):531-7.
- Grimaldi M, Gouyon B, Michaut F, et al; Severe respiratory syncytial virus bronchiolitis: epidemiologic variations associated with the initiation of palivizumab in severely premature infants with bronchopulmonary dysplasia. Pediatr Infect Dis J. 2004 Dec;23(12):1081-5.
- Nuijten MJ, Wittenberg W, Lebmeier M; Cost effectiveness of palivizumab for respiratory syncytial virus prophylaxis in high-risk children: a UK analysis. Pharmacoeconomics. 2007;25(1):55-71.
- Immunisation - The Green Book; Dept of Health
- Ng DK, Lau WY, Lee SL; Pulmonary sequelae in long-term survivors of bronchopulmonary dysplasia. Pediatr Int. 2000 Dec;42(6):603-7.
|Original Author: Dr Hayley Willacy||Current Version: Dr Colin Tidy|
|Last Checked: 19/11/2010||Document ID: 1890 Version: 24||© EMIS|
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