A. Bronchopulmonary Dysplasia (BPD) [1]

1. Chronic pulmonary disorder occurring mainly in premature infants
2. Infants with respiratory insufficiency receiving supplemental oxygen and ventilatory support have the highest incidence
3. Pathogenesis
   1. Largely unknown
   2. Acute and chronic lung injury occurs
   3. Fibrosis and remodeling ensues
   4. High airway oxygen levels and pressures appear to contribute
4. Treatment and Prevention [1]
   1. Symptomatic treatment in neonates who develop disease
   2. Prophylactic systemic glucocorticoids given to infants at risk decrease risk of BPD
   3. Thus, dexamethasone IV is usually given to reduce BPD risk
   4. Early postnatal prophylactic dexamethasone is no longer recommended as it causes long term redcution in IQ, motor skills and coordination, and overall disabilities [2]
   5. Inhaled nitric oxide reduces risk of BPD in premature infants, particularly >1000 gm [3,4]
   6. Inhaled nitric oxide reduces risk of any chronic lung disease and improved neurodevelopment in premature infants [4,5]
   7. Nitric oxide begun age 7-21 days in infants birthweight <1250gm reduced development of BPD and hospital stay without any short-term safety concerns [10]
   8. Nitric oxide for preterm infants <34 weeks and weight 1000-1250gm reduced incidence of BPD ; no effect on BPD in infants 500-1000gm [11]
   9. Nitric oxide for preterm infants <34 weeks and weight 500-1250gm reduced incidence of brain injury (17.5% with nitric oxide; 24% with placebo) [11]
   10. Inhaled glucocorticoids do not reduce risk of BPD, but reduced use of systemic steroids
   11. Increased risk for respiratory syncytial virus (RSV); prophylaxis indicated

B. Choanal Atresia

1. Failure of normal nares opening
2. Attempt to pass nasogastric (NG) tube down each nostril

C. Congenital Lobar Pneumonia

1. Partial Bronchial Obstruction
2. Pulmonary Alveolar Fibrosis

D. Diaphragmatic Hernia

1. Abnormally large hole in normal diaphragm (crux) opening for esophagus
2. Esophagus pulls stomach up into chest
3. May lead to gastroinestinal problems and reduced lung development
4. Diagnosis in utero may be helpful to allow early correction

E. Esophageal Atresia

1. 85% with distal tracheoesophageal (T-E) fistula
2. Failure of T-E Septal Fusion
3. Drooling, Vomitus with Bile, Cough

F. Pneumoperitoneum

1. Ruptured Greater Curvature of Stomach
2. Air in abdomen
3. Surgical Emergency

G. Pneumothorax

1. Relatively uncommon
2. May lead to abnormal lung development

H. Persistent Pulmonary Hypertension of the Newborn (PPHN)

1. Common in neonates with respiratory failure
2. Pulmonary hypertension (HTN) and extrapulmonary right to left shunting
   1. Patent foramen ovale
   2. Ductus arteriosus
3. Serotonin Selective Reuptake Inhibitors (SSRI) [12]
   1. SSRI's associated with increased risk of PPHN
   2. Exposure of fetus after 20th week gestation associated with 6X increased risk
   3. SSRI use before the 20th week or use of other antidepressants had no increase in risk
   4. Caution with use of SSRIs in pregnant women, particularly 3rd trimester
4. Nitric Oxide
   1. Potent vasodilator important for maintaining low pulmonary pressures
   2. Reduced levels of NO and metabolites may be genetically determined in neonates [6]
   3. Neonatal pulmonary hypertension associated with reduced NO precursors and levels [6]
   4. Some benefit on oxygenation, brain development in premature infants >1000gm at birth [3,4,5]
5. Disease often worsens and becomes refractory to treatment
6. Treatment
   1. High dose oxygen
   2. Extracorporeal membrane oxygenation (ECMO) - improves survival
   3. Inhaled nitric oxide cause bronchial dilation and can improve oxygenation
   4. Nitric oxide reduced need for ECMO and was associated with less chronic lung disease [7]
   5. Nitric oxide did not affect 30 day mortality [7]

I. Respiratory Distress Syndrome (RDS)

1. Formerly called Hyaline Membrane Disease
2. Histopathology is similar to ARDS
3. Occurs primarily in premature infants
4. Due to insufficient Surfactant Production by Type II Alveolar Cells
5. Treatment
   1. Glucocorticoids given to the mother can hasten Type II alveolar surfactant production
   2. Exogenous surfactant
   3. Surfactants are approved for prevention as well as treatment of RDS
   4. Surfactants reduce short and long term morbitiy and mortality
6. Surfactant [8]
   1. Natural and synthetic surfactants available
   2. Synthetic surfactant (colfosceril, Exosurf®) improves lung function and mortality
   3. Porcine lung surfactant extract (Curosurf®) is now FDA approved for newborn RDS
   4. Bovine lung surfactant extract Calfactant (Infasurf®) and beractant (Survanta®)
   5. Poractant alpha, porcine derived surfactant, reduced mortality >60% compared with synthetic pumactant [9]

J. Evaluation

1. Nasogastric tube down Nares
2. Chest and Abdominal Radiography
3. Examine pharynx and larynx
4. Computerized Tomographic (CT) Scan to evaluate all anatomy

References

1. Cole CH, Colton T, Shah BL, et al. 1999. NEJM. 340(13):1005
2. Yeh TF, Lin YJ, Lin HC, et al. 2004. NEJM. 350913):1304
3. Van Meurs KP, Wright LL, Ehrenkranz RA, et al. 2005. NEJM. 353(1):13
4. Schrieber MD, Gin-Mestan K, Marks JD, et al. 2003. NEJM. 349:2099
5. Mestan KKL, Marks JD, Hecox K, et al. 2005. NEJM. 353(1):23
6. Pearson DL, Dawling S, Walsh WF, et al. 2001. NEJM. 344(24):1832
7. Clark RH, Kueser TJ, Walker MW, et al. 2000. NEJM. 342(7):469
8. Curosurf. 2000. Med Let. 42(1074):27
9. Ainsworth SB, Beresford MW, Milligan DWA, et al. 2000. Lancet. 355(9213):1387
10. Ballard RA, Truog WE, Cnaan A, et al. 2006. NEJM. 355(4):343
11. Kinsella JP, Cutter GR, Walsh WF, et al. 2006. NEJM. 355(4):354
12. Chambers CD, Hernandez-Diaz S, Van Marter LJ, et al. 2006. NEJM. 354(6):579