Bronchopulmonary Dysplasia NICU Night Curriculum Learning Objectives вЂў To understand the clinical course and presentation of bronchopulmonary dysplasia in the premature infant вЂў To understand the epidemiology and physiology of bronchopulmonary dysplasia вЂў To review the management of bronchopulmonary dysplasia Case #1 вЂў ItвЂ™s July, and youвЂ™ve just started your first month as a pediatrics internвЂ¦ and youвЂ™re scheduled to start in the NICU. Someone signed out to you last night, but they were hurrying to make it in time for their вЂњIвЂ™ll never be an intern again partyвЂќ and you didnвЂ™t ask a lot of questions because you didnвЂ™t want to look dumb (already!). So you really donвЂ™t have any clue what is going on, and here is your first patientвЂ¦ Case: One-liner вЂў Baby Smith is an ex-23 wk infant, now 60 days old, who has a history of RDS, grade II IVH, and feeding intolerance, who is currently still intubated. вЂў SOвЂ¦ what can you gather so far? o What is the babyвЂ™s corrected gestational age? o How bad do you think his lungs are? o What other things might you want to know from his history that would support your assessment of his lung disease? Case: One-Liner вЂў Baby Smith is an ex-23 wk infant, now 60 days old, who has a history of RDS, grade II IVH, and feeding intolerance, who is currently still intubated вЂў SOвЂ¦ what can you gather so far? o What is the babyвЂ™s corrected gestational age? вЂў 32 weeks o How bad do you think his lungs are? вЂў Pretty bad o What other things might you want to know from his history that would support your assessment of his lung disease? вЂў Maternal history, delivery, hospital course Case: Pertinent History вЂў Maternal history: o o o вЂў Birth history/Delivery room course: o o o o вЂў Mom is a 25yo G2P2 who came into L&D at 23 wks with preterm labor and rupture of membranes. Mom did not receive antenatal steroids Serologies: A+, RPR NR, Hep B neg, RI, HIV neg, GBS unknown The peds team was called to a code blue for 23 wk prematurity and precipitous delivery (she delivered 1 hour after arriving to L&D). At delivery, the infant had a HR>100, but no respiratory effort, and was limp and blue He required intubation and PPV and color/tone improved. Apgars were 2 and 7. BW was 600grams. WHAT ASPECTS OF THIS HISTORY MAKE YOU WORRY ABOUT HIS LUNGS? o His risk factors for chronic lung disease are: Prematurity, NO antenatal steroids, low birth weight Case: NICU course вЂў NICU course: o Respiratory: Infant was brought back to unit intubated, but was found to have a pneumothorax on admission CXR. Chest tube was placed and no other doses of surfactant were given. o Since then, infant has been intubated. Around DOL 30, extubation was attempted, but the baby had significant desaturations and increased work of breathing and was reintubated. Same story around DOL 50, but he lasted maybe a week before reintubation. Case: At the bedside вЂў At the bedside: o Physical exam: вЂў Gen: You see a small baby, who is intubated. вЂў CV:When you listen to his chest, you hear regular heart sounds and III/VI systolic murmur. вЂў Pulm: You notice coarse breath sounds bilaterally, with occasional rales, fair chest rise with each ventilator breath and occasionally, he spontaneously takes his own breaths. вЂў Abdom: His abdomen is soft and nondistended вЂў Neuro: He moves his arms and legs around while you are examining him. o You look over at his ventilator and heвЂ™s on the following settings: вЂў FiO2 55%, Pressure control 20, Pressure support 14, rate 45, I-time 0.35, PEEP 6 Case: Imaging вЂў His chest xray today: o What do you see on this xray (Give 4 findings)? Case: Imaging o What do you see on his xray? вЂў ETT вЂў Nasal Gastric Tube вЂў Normal cardiac sillhouette вЂў Bones look normal вЂў GROUND GLASS APPEARANCE OF LUNGS Blood Gas вЂў Labs: BMP, CBC are normal. Capillary blood gas today: 7.25/65/28/+1 o What does this gas show? вЂў RESPIRATORY ACIDOSIS Case: Diagnosis? вЂў Based on this babyвЂ™s history, exam, labs and xray findings, what do you think is the diagnosis? вЂў This baby is likely developing bronchopulmonary dysplasia (or chronic lung disease) o but we will try and make some management changes during your month in the NICU to help him out. o We can then evaluate the baby at 36 weeks corrected GA (the end of your month) to see if he fits the criteria for BPD. Bronchopulmonary Dysplasia вЂў Most common severe complication of prematurity вЂў First defined by Northway in 1967: lung disease resulting from prolonged mechanical ventilation in premature infants with surfactant deficiency вЂў NICHD criteria: need for oxygen based on GA and severity of disease Bronchopulmonary Dysplasia вЂў вЂњOld BPDвЂќ (before surfactant and steroids) o Cystic changes, heterogeneous aeration вЂў вЂњNew BPDвЂќ (after surfactant and steroids) o More uniform inflation and less fibrosis, absence of small and large airway epithelial metaplasia and smooth muscle hypertophy o Some parenychmal opacities, but more homogenous aeration and less cystic areas o PATHOLOGIC HALLMARKS: larger simplified alveoli and dysmorphic pulmonary vasculature Epidemiology вЂў Incidence: o 42-46% (BW-501-750g) o 25-33% (BW=751-1000g) o 11-14% (BW=1001=1250g) o 5-6% (BW=1251-1500g) вЂў Risk factors: o Prematurity, low BW o White boys o Genetic heritability Pathogenesis Pathophysiology вЂў Old BPD: o Airway injury, inflammation and parenchymal fibrosis due to mechanical ventilation and oxygen toxicity вЂў New BPD: o Decreased septation and alveolar hypoplasia leading to fewer and larger alveoli, so less surface area for gas exchange o Dysregulation of vascular development leading to abnoraml distribution of alveolar capillaries and thickened muscular layer of pulmonary arterioles Clinical Presentation вЂў Need for supplemental oxygen. Hypoxemic and hypercapneic. вЂў Exam: tachypnea, retractions, scattered rales вЂў CXR: diffusely hazy with alternating areas of atelectasis and hyperexpansion; streaky densities or cystic areas, edema вЂў CLINICAL COURSE: Tend to slowly improve and wean off respiratory support. May have intermittent episodes of acute deterioration if severe disease. May also develop pulmonary hypertension when severe Treatment: Prevention вЂў Prevention: o Avoidance of preterm birth o Antenatal steroids Treatment: management by phases Case: Current Management вЂў FEN: TF 150ml/kg/d of continuous NGT feeds of SSC 24 kcal. Has been gaining about 70 grams/week for the last two weeks. вЂў Resp: currently intubated at the aforementioned settings with blood gas from last slide. вЂў CV: last echo done 2 weeks ago shows a small PDA and PFO. No evidence of RVH. вЂў Heme: Hematocrit=24 checked 2 days ago вЂў Meds: multivitamin, iron, caffeine вЂў So, in practical terms, what things could you do to optimize his management over the next few weeks? Case: Current Management вЂў FEN: o Fluid restriction/diuretics o Optimize caloric intake and growth вЂў Resp: o Ventilator management o Give steroids before another extubation attempt? вЂў CV: o PDA closure? вЂў Heme: o Transfusion to improve oxygen carrying capacity Prognosis вЂў Morbidity: o Higher rates of hospitalization in the first year of life e.g. resp infections o Respiratory symptoms may persist into adulthood вЂў Abnormal pulmonary function вЂў Asthma-like symptoms o Airway abnormalites e.g. tracheomalacia o Pulmonary artery hypertension вЂў BPD associated with worse neurodevelopmental outcomes Review Questions вЂў 1. What is BPD? вЂў 2. Who is at risk for developing BPD? вЂў 3. How is old and new BPD different? вЂў 4. What is the clinical course of BPD? вЂў 5. What are some methods of managing BPD? вЂў 6. What is the long-term outcomes of BPD? Review Answers вЂў 1. What is BPD? Lung disease of premature infants, characterized by abnormal alveolarization and pulmonary vascularization. вЂў 2. What are the greatest risk factors for developing BPD? Prematurity and low birth weight вЂў 3. How is old and new BPD different? Old is before surfactant and antenatal steroids, and has more inflammation and fibrosis, whereas new BPD is post-surfactant and steroids, and shows fewer and larger alveoli. Review Answers вЂў 4. What is the clinical course of BPD?. Infants with BPD tend to improve slowly over time, requiring less and less respiratory support. But in severe cases, infants can have вЂњBPD exacerbationsвЂќ, require tracheostomy, or develop cor pulmonale. вЂў 5. What are some methods of managing BPD? Fluid restriction, diuretics, optimize nutrition, permissive hypercapnea, lower goal oxygen saturations, steroids вЂў 6. What is the long-term outcomes of BPD? Infants with BPD may have abnormal respiratory function, asthma-like symptoms, airway problems, and/or require more frequent hospitalization later in childhood. In addition, studies show that BPD is associated with worse neurodevelopmental outcomes. References вЂў Adams et al. Pathogenesis and clinical features of bronchopulmonary dysplasia. UpToDate. May 2011. вЂў Bhandari A and Vineet Bhandari. Pitfalls, Problems, and Progress in Brocnhopulmonary Dysplasia. Pediatrics. 2009;123; 1562-1573. вЂў Fanaroff AA, et al. Trends in neonatal morbidity and mortality for very low birthweight infants. Am J Obstet Gynecol. 2007: 196(2): 147.e1-147.e8. вЂў Harris et al. Pulmonary outcomes in bronchopulmonary dysplasia. UpToDate. May 2011. вЂў Jobe Alan H. The new bronchopulmonary dysplasia. Current Opin Peds. 2011, 23: 167-172.