Chapter 31 Neonatal and Pediatric Respiratory Disorders

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi22er Inc. 2 Objectives  Discuss the clinical findings, radiographic abnormalities, and treatment of patients with RDS.  Describe the clinical manifestations and treatment of patients with transient tachypnea of the newborn (TTN).  Describe the pathophysiology, presentation, and treatment of meconium aspiration syndrome.  Discuss the clinical signs and symptoms associated with bronchopulmonary dysplasia and the approaches used to manage these infant.

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi33er Inc. 3 Objectives (cont.)  Discuss the etiology and treatment of apnea of prematurity.  Describe the pathophysiology, diagnosis, and treatment of persistent pulmonary hypertension of the newborn (PPHN).  Describe the pathophysiology, diagnosis, and treatment of congenital diaphragmatic hernia.  Describe the anatomic defects associated with tetralogy of Fallot.

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi44er Inc. 4 Objectives (cont.)  Describe the clinical presentation of a ventricular septal defect.  Define the epidemiologic factors associated with increased risk of SIDS.  Discuss the respiratory problems associated with gastroesophageal reflux disease.  Describe the clinical findings commonly observed in patients with bronchiolitis.

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi55er Inc. 5 Objectives (cont.)  Describe the clinical features and treatment of children epiglottitis.  Describe the clinical manifestations and treatment of cystic fibrosis.

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi66er Inc. 6 Lung Parenchymal Disease Respiratory distress syndrome (RDS)  Also called hyaline membrane disease  Disorder of prematurity characterized by  Qualitative surfactant deficiency Insufficient amounts released by type II cells Insufficient amounts released by type II cells Poor quality so cannot decrease surface tension Poor quality so cannot decrease surface tension  Decreased alveolar surface area  Increased small airway compliance  Patent ductus arteriosus

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi77er Inc. 7 Lung Parenchymal Disease (cont.) Respiratory distress syndrome (cont.)  Lung prematurity, and particularly the surfactant deficiency, sets up the following sequelae.  Alveolar instability and collapse, which leads to increased WOB  Simultaneously increased surface tension draws fluid into the alveoli  Combined, these cause impaired oxygenation with hypoxemia and acidosis, which lead increased PVR  Increases right-to-left shunting through the PDA  This worsens acidosis, hypoxemia, and surfactant production, which establishes a downward spiral

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Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi99er Inc. 9 Lung Parenchymal Disease (cont.) Respiratory distress syndrome (cont.)  Clinical manifestations  Tachypnea occurs soon after birth  Followed by worsening retractions, paradoxical breathing, and grunting Nasal flaring may be seen. Nasal flaring may be seen.  Chest auscultation: fine inspiratory crackles  Diagnosis is made from chest radiography. Diffuse, hazy reticulogranular densities, air bronchograms, and low lung volumes are typical Diffuse, hazy reticulogranular densities, air bronchograms, and low lung volumes are typical

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Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi1212er Inc. 12 Lung Parenchymal Disease (cont.) Respiratory distress syndrome (cont.)  Treatment  Noninvasive CPAP (nasal prongs) preferred Trial with 4 to 6 cm H 2 O Trial with 4 to 6 cm H 2 O Intubate and MV if Pa O 2 does not improve, apnea or acidosis occurs Intubate and MV if Pa O 2 does not improve, apnea or acidosis occurs  MV with PEEP: goals are to prevent alveolar collapse and provide adequate V A Optimal PEEP provides lowest Pa CO 2, highest Pa O 2 Optimal PEEP provides lowest Pa CO 2, highest Pa O 2 If high Pa CO 2 persists, must increases f or PIP If high Pa CO 2 persists, must increases f or PIP.

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi1313er Inc. 13 Lung Parenchymal Disease (cont.)  Treatment of Respiratory distress syndrome (cont.)  Surfactant replacement instilled into trachea indicated for all RDS patients  High-frequency ventilation (HFV)

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi1414er Inc. 14 Lung Parenchymal Disease (cont.) Transient tachypnea of the newborn (TTN): type II RDS  May be most common newborn respiratory disorder  Term babies with no specific predisposing factors  Probably occurs due to delayed clearance fetal lung fluid  Birth canal squeeze normally accounts two-thirds clearance Cesarean section avoids this squeeze Cesarean section avoids this squeeze  Lymphatics’ absorption accounts for final third Immature lymphatics impairs absorption Immature lymphatics impairs absorption

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi1515er Inc. 15 Lung Parenchymal Disease (cont.) Transient tachypnea of the newborn (cont.)  Clinical manifestations  No. 1 is tachypnea  V A, pH, and Pa CO 2 are normal. Features of chest radiograph May look like pneumonia May look like pneumonia Hyperinflation Hyperinflation Pleural effusions Pleural effusions Perihilar streaking (lymphatic engorgement) Perihilar streaking (lymphatic engorgement).

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi1616er Inc. 16 Lung Parenchymal Disease (cont.) Transient tachypnea of the newborn (cont.)  Treatment  Responds well to low F IO 2 with or without CPAP  May use antibiotics, TTN hard to tell from pneumonia  Most have rapid response (24 to 48 hours)

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi1717er Inc. 17 Lung Parenchymal Disease (cont.) Meconium aspiration syndrome (MAS)  Disorder of term or near-term infants, associated with perinatal depression and asphyxia  Pathophysiology  Depression, asphyxia lead to passing of meconium  MAS involves three primary problems. Pulmonary obstruction due to meconium plugging Pulmonary obstruction due to meconium plugging Lung damage due to chemical injury Lung damage due to chemical injury Persistent pulmonary hypertension (PPHN) Persistent pulmonary hypertension (PPHN)

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi1818er Inc. 18 Lung Parenchymal Disease (cont.) Meconium aspiration syndrome (MAS)  Clinical manifestations  Gasping respirations, tachypnea, grunting, retractions  Chest radiograph Irregular pulmonary densities (atelectasis) Irregular pulmonary densities (atelectasis) Hyperlucent areas (hyperinflation) Hyperlucent areas (hyperinflation)  ABGs: hypoxemia, mixed acidosis due to PPHN  Treatment  Immediate intubation and suctioning  Mechanical ventilation  HFV, surfactant, and NO therapy may all be used

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Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi2121er Inc. 21 Lung Parenchymal Disease (cont.) Bronchopulmonary dysplasia (BPD)  Pathophysiology: Multifactorial  Atelectrauma is a result and cause of lung injury.  Volutrauma injures airways and lung parenchyma.  Above two synergistically increase lung injury, necessitate oxygen therapy (leads to oxygen toxicity)  Immaturity, genetics, malnutrition, oxygen toxicity, hypoxia, MV all contribute to BPD development

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi2222er Inc. 22 Lung Parenchymal Disease (cont.) Bronchopulmonary dysplasia (cont.)  Clinical manifestations  Progressive respiratory distress at 2–3 weeks of life IF did not require O 2 and MV before, will now IF did not require O 2 and MV before, will now  Chest radiograph shows diffuse areas of atelectasis, emphysema, and fibrosis.  ABGs show varying hypoxemia and hypercapnia.  Treatment  Prevention of atelectrauma and volutrauma is KEY

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi2323er Inc. 23 Lung Parenchymal Disease (cont.) Bronchopulmonary dysplasia (cont.)  Treatment  Establish optimal FRC in delivery room  Early use of surfactant  Minimize lung damage: monitor carefully and use lowest oxygen and MV settings possible  Diuretics to treat pulmonary edema  Antibiotics for pulmonary infections  Chest physiotherapy for retained secretions  Bronchodilator therapy to decrease R aw  Steroids used cautiously as create as many problems as solve

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Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi2525er Inc. 25 Control of Breathing Apnea of prematurity  Common in premature infants  Apnea is abnormal if >15 seconds OR it causes cyanosis, pallor, hypotonia, or bradycardia  Central apnea: no respiratory effort during apnea  Obstructive apnea: effort but no flow  Mixed apnea: combination of central and obstructive apnea

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi2626er Inc. 26 Control of Breathing Apnea of prematurity (cont.)  Etiology  Immature chemo-control of respiratory drive

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi2727er Inc. 27 Control of Breathing (cont.)

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi2828er Inc. 28 Pulmonary Vascular Disease Persistent pulmonary hypertension of the newborn (PPHN)  Prolonged postpartum fetal circulation due to ⇑ PVR  Pathophysiology  Pulmonary blood flow is low due to right-to-left shunt through a patent foramen ovale or ductus arteriosus.  Thee types of PPHN  Vascular spasm: triggered by hypoxemia or pain  Increased muscle wall thickness: chronic  Decreased cross-sectional area of vasculature Lung hypoplasia Lung hypoplasia

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi2929er Inc. 29 Pulmonary Vascular Disease (cont.) Persistent pulmonary hypertension of the newborn (cont.)  Clinical manifestations  Suspect when rapidly changing Sp O 2, hypoxemia worse than indicated on chest radiograph  Detected by performing preductal and postductal Sp O 2 Preductal Sp O 2 > 5% postductal Sp O 2 Preductal Sp O 2 > 5% postductal Sp O 2

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3030er Inc. 30 Pulmonary Vascular Disease (cont.) Persistent pulmonary hypertension of the newborn (cont.)  Treatment  Correct underlying problem Hypoxemia with oxygen, surfactant for RDS Hypoxemia with oxygen, surfactant for RDS  May require intubation, MV, and sedation  Often require: paralysis, HFV, worst cases ECMO

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3131er Inc. 31 Congenital Abnormalities Affecting Respiration Congenital airways diseases  Three mechanisms  Internal obstruction Laryngomalacia, tracheomalacia, laryngeal webs Laryngomalacia, tracheomalacia, laryngeal webs Stridor, gas-trapping, wheezing, accessory muscles Stridor, gas-trapping, wheezing, accessory muscles  External obstruction (symptoms similar to internal) Neck or thoracic mass, vascular rings Neck or thoracic mass, vascular rings  Airway disruptions (TE fistula) Five types, all manifest as difficulty swallowing, frothing at mouth, and choking Five types, all manifest as difficulty swallowing, frothing at mouth, and choking Often associated with other congenital abnormalities Often associated with other congenital abnormalities

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3232er Inc. 32 Congenital Abnormalities Affecting Respiration (cont.) Lung malformations  Most common cystic adenomatoid malformation: C-CAM  Usually treat by surgical resection of affected lobe  Symptoms of volume loss, cardiopulmonary compromise Congenital diaphragmatic hernia  Manifests as severe respiratory distress, scaphoid abdomen  Combination of lung hypoplasia and abnormal development

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3333er Inc. 33 Congenital Abnormalities Affecting Respiration (cont.) Congenital diaphragmatic hernia (cont.)  Treatment  Initially intubation, paralysis, MV, continuous gastric sx  Repair delayed for PVR to fall due to adequate V A  Severe cases may require HFV and ECMO. Abdominal wall abnormalities  Affect breathing as infants are abdominal breathers  If severe may require MV Neuromuscular control  Spinal muscular atrophy, congenital myasthenia gravis  May require MV if severe

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3434er Inc. 34 Congenital Heart Disease Cyanotic congenital heart defects  Tetralogy of Fallot: comprised of  Pulmonary stenosis, VSD, dextroposition aorta, RVH  Timing of surgical repair dependent on case  Transposition of the great arteries  Manifests as moderate to severe cyanosis at birth  Emergency atrial septostomy relieves distress  Perform arterial switch operation at 2–3 weeks of life

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3535er Inc. 35 Congenital Heart Disease (cont.) Acyanotic congenital heart defects  Ventricular septal defect (VSD): most common  Results in left-to-right shunt and CHF  Appears 6–8 weeks as PVR falls  Atrial septal defect (ASD): typically of little importance  Most common; incomplete closure of foramen ovale  Patent ductus arteriosus (PDA)  Typically occurs in premature infants  May act as a right-to-left or left-to-right shunt depending on SVR and PVR

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Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3737er Inc. 37 Pediatric Respiratory Disorders Sudden infant death syndrome (SIDS)  Leading cause of death in infants < 1 year of age  Prevention of SIDS  Identification of infant at risk  Train family in apnea monitoring and CPR.  Place patient in supine or side-lying position.  Reduce soft objects in sleeping environment.

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3838er Inc. 38 Pediatric Respiratory Disorders (cont.)

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi3939er Inc. 39 Pediatric Respiratory Disorders (cont.) Gastroesophageal reflux disease (GERD)  Associated respiratory problems include  Reactive airways disease, aspiration pneumonia, laryngospasm, stridor, chronic cough, choking, apnea  Once diagnosed, medical and surgical management

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi4040er Inc. 40 Pediatric Respiratory Disorders (cont.) Bronchiolitis: caused by respiratory syncytial virus (RSV)  Clinical manifestations  Usually follows a URTI  Slight fever and cough worsen to dyspnea, tachypnea  Inspiratory and expiratory wheezing may develop  Radiograph shows hyperinflation and consolidation  Prophylaxis: immunization recommended BPD infants  Treatment: relief of airway obstruction and hypoxemia, MV with prolonged expiration used in most severe cases

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi4141er Inc. 41 Pediatric Respiratory Disorders (cont.) Croup: also called laryngotracheobronchitis  Viral infection resulting in subglottic swelling: most common cause of obstruction in 6-month- to 6-year- olds  Clinical manifestations  Follows 2–3 days of nasal congestions, fever, cough  Progressive inspiratory and expiratory stridor  Barking cough is characteristic  Progression to dyspnea, cyanosis, and exhaustion  Chest radiograph shows classic “steeple sign”

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Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi4343er Inc. 43 Pediatric Respiratory Disorders (cont.) Croup (cont.)  Treatment  Mild to moderate disease may be limited to cool mist  May require supplemental oxygen  Aerosolized racemic epinephrine and dexamethasone may decrease severity of respiratory symptoms.  Budesonide may reduce severity of symptoms.  Severe cases progressing despite therapy may require intubation and mechanical ventilation.

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi4444er Inc. 44 Pediatric Respiratory Disorders (cont.) Epiglottitis (cause H. influenzae type B)  Life-threatening infection resulting in supraglottic swelling  Clinical manifestations  High fever, sore throat, stridor, labored breathing  NOT associated with barking cough  May have difficulty swallowing and muffled voice  Lateral neck radiograph shows “thumb sign”  Treatment: proceed with great care  Elective intubation under general anesthesia, place on CPAP with low PSV (3 cm H 2 O)

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Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi4646er Inc. 46 Pediatric Respiratory Disorders (cont.) Cystic fibrosis  Most common lethal genetic disease in white Americans  Gene mutation affecting chloride movement, particularly in exocrine glands  Clinical manifestations  Most severely affected organs are: Sweat glands, pancreas, and lungs Sweat glands, pancreas, and lungs  Skin is very salty: mother notes when kissing infant Sweat chloride test is diagnostic Sweat chloride test is diagnostic  Pancreatic insufficiency leads to malnutrition, diarrhea, and steatorrhea

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi4747er Inc. 47 Pediatric Respiratory Disorders (cont.) Cystic fibrosis (cont.)  Clinical manifestations  Lung disease is leading cause of death.  Patients produce copious amounts of thick sputum. Retained secretions lead to recurrent infections, atelectasis, pneumonia, or lung abscesses. Retained secretions lead to recurrent infections, atelectasis, pneumonia, or lung abscesses.

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevi4848er Inc. 48 Pediatric Respiratory Disorders (cont.) Cystic fibrosis (cont.)  Treatment  Pancreatic enzyme supplements  Regular chest physiotherapy, strenuous exercise  DNase, 7% saline preserve lung function  Antibiotics are crucial to treat bronchiectatic flare- ups  May use antiinflammatory agents and bronchodilators