Respiratory Disorders Respiratory Disorders in the Newborn PERINATOLOGY

Introduction Respiratory distress  encountered frequently  the most frequent indication for re-evaluation Potentially life-threatening conditions Early recognition, timely referral, appropriate treatment essential Aly H, Pediatrics in Review 2004;25: Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

…introduction The key to succesful management  Complete maternal and newborn history  Complete physical examination  Recognize the common respiratory disorder  Differentiate among various diagnostics entities  Identify those that are life-threatening Aly H, Pediatrics in Review 2004;25:

Definition Characterized by one or more of the following :  Nasal flaring  Chest retractions  Tachipnea (RR > 60/min)  Grunting Aly H, Pediatrics in Review 2004;25:

Advanced degree of respiratory distress :  Cyanosis  Gasping  Choking  Apnea  Stridor Aly H, Pediatrics in Review 2004;25: …definition

Evaluation of Respiratory Distress Using Down’s Score Audible with ear Audible by stethoscope No gruntingGrunting No air entryMild decrease in air entry Good bilateral air entry Air Entry Cyanosis on O 2 Cyanosis relieved by O 2 No cyanosisCyanosis Severe retractions Mild retractions No retractionRetractions > 80/min60 – 80/min< 60/minRespiratory Rate 210

Score < 4 No respiratory distress Score 4 -7 Respiratory distress Score > 7 Impending respiratory failure (Blood gases should be obtained) …evaluation

Initial assesment To identify conditions that require prompt support  Obstructed airway (gasping, choking,stridor)  Insufficient breathing (apnea,poor resp. effort)  Circulatory collapse (bradycardia, hypotension, poor perfusion)  Poor oxygenation (cyanosis)

…initial assesment Manage the infants promptly  Immediate oxygen support  Possibly bag and mask ventilation  Even intubation and mechanical ventilation

History Maternal history  Drug abuse  Diabetes Melitus  Infections

…history Obstetrical histories  Gestational age (if preterm  HMD)  Results of fetal assesment and fetal monitoring during labor & delivery  Complications at delivery  birth trauma, presence of meconium, perinatal depression, premature rupture of membranes

Details of the presenting respiratory symptoms  Coughing and choking during feeding  oropharyngeal aspiration and tracheoesophageal fistula should be considered If symptoms follow the feeding  reflux with aspiration suspected  recurrent emesis  Gradually improving symptoms  TTN Gradual deterioration  pneumonia / sepsis  Onset of distress …history

Preterm- Possible Etiology Early progressiveRespiratory distress syndrome or hyaline membrane disease (HMD) Early transientAsphyxia, metabolic causes, hypothermia AnytimePneumonia Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Term- Possible Etiology Early well lookingTTN, polycythemia Early severe distressMAS, asphyxia, malformations Late sick with hepatomegaly Cardiac Late sick with shockAcidosis AnytimePneumonia Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Physical examination Inspection is the first and most important tool  Apnea, poor perfusions, retractions, cyanosis  Inspiratory stridor  upper airway obstruction Stridor (previous history of intubation)  airway injury, such as subglottis stenosis  Asymmetric chest movement + severe distress  maybe tension pneumothorax  Scaphoid abdomen  diaphragmatic hernia Aly H, Pediatrics in Review 2004;25:

…physical examination Auscultation  Symmetry and adequacy of air exchange  Abnormal breaths sound  The presence of heart murmur Chest transilumination  to detect pneumothorax Aly H, Pediatrics in Review 2004;25:

…physical examination Chest examination  Air entry  Mediastinal shift  Hyperinflation  Hearts sounds Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

…physical examination Suspect surgical cause  Obvious malformation  Scaphoid abdomen  Frothing  History of aspiration Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Common Causes of RD - Medical  Transient tachypnea of the newborn (TTN)  Hyaline membrane disease (HMD)  Meconium aspiration syndrome (MAS)  Air leak syndrome  Pneumonia  Congenital heart diseases

Surgical Causes of Respiratory Distress  Tracheo-esophageal fistula  Diaphragmatic hernia  Lobar emphysema  Pierre-Robin syndrome  Choanal atresia Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Investigations  Chest X-ray  Complete blood count (anemia, polycythemia, sepsis)  Arterial blood gas  Glucose check (hypoglycemia)  Blood culture (sepsis, pneumonia)

Treatment  After stabilization, treat the cause of RD  Use CPAP  Avoid unnecessary exposure to oxygen  Antibiotics until sepsis is ruled out Aly H, Pediatrics in Review 2004;25:

Transient Tachypnea of the Neonate (TTN) Definition  Respiratory distress of near term or term neonate  Transient pulmonary edema resulting from delayed clearance of fetal lung fluids

Pathogenesis  Lung fluids produce actively in utero by chloride pump  water & chlor to alveolar space  2-3 d before delivery  transformation process  pulmonary epithelium changes to Na-absorbing  lung fluid away from alveolar space  Low oncotic pressure  favors fluid movement from alveolar space into the interstitium

 Prostaglandin secretion  lymphatic dilation  accelerates fluid clearance from interstitium  Lung expansion  water to interstitium  gradually remove from lung by the lymphatic system and pulmonary blood vessels …pathogenesis

Risk Factors  Cesarean section without labor  Macrosomia  Male sex  Prolonged labor  Excessive maternal sedation  Low Apgar score (< 7 at 1 minute)

Clinical Presentation  Tachipnea shortly after delivery  May have grunting, nasal flaring, rib retractions, and cyanosis  Respiratory symptoms improve as pulmonary fluid is mobilized, and this is usually associated with diuresis  Usually does not last longer than 72 hours

 Increased interstitial markings and occasionally fluids in the interlobar fissure  Occasionally pleural effusion and signs of alveolar edema may be seen Aly H, Pediatrics in Review 2004;25: Chest X-Ray

Management  Oxygen therapy  some infants may need NCPAP  Feeding as tachypnea improves

Prognosis  Self-limited disease  There is no risk of recurrence or further pulmonary dysfunction

Hyaline Membrane Disease Definition  Hyaline membrane disease (HMD) is also called respiratory distress syndrome (RDS)  This condition usually occurs in a preterm neonate  Premature lungs are surfactant deficient

Incidence  About 25% of neonates born at 32 weeks gestation  The incidence increases with increasing prematurity

Predisposing Factors  Prematurity  Male sex  Neonate of diabetic mother  Asphyxia

Protective Factors  Chronic intrauterine stress Prolonged rupture of membranes Maternal hypertension Narcotic use Intrauterine Growth Retardation (IUGR) or Small for Gestational Age (SGA)  Corticosteroids – Prenatal

Clinical Manifestation  Increasing tachypnea (> 60/min)  Chest retractions  Cyanosis on room air that persists or progresses over the first hours of life.  Decreased air entry  Grunting

Investigations  Laboratory Studies: Blood gases: hypoxia, hypercarbia, acidosis CBC and blood culture are required to rule out infection Serum glucose levels are usually low  Chest X-ray Study: Reveals ground glass appearance with air bronchograms

Management Resuscitation by experienced pediatric staff :  Prompt gentle stimulation and inflation to produce and maintain the FRC by CPAP and intubation  Give surfactant as soon after intubation as possible  Minimise heat loss

Nasal CPAP

Meconium Aspiration Syndrome (MAS) The respiratory distress secondary to meconium aspiration by the fetus in utero or by the neonate during labor and delivery MAS   10-26% of all deliveries and  mostly in term and postterm deliveries and  may represent fetal hypoxemia

Pathogenesis Aspiration of meconium  Airway obstruction (ball and valve)  Chemical pneumonitis with activation of several inflammatory mediators  Inactivation of lung surfactan

…pathogenesis Aspiration of meconium  Thin MAS  chemical pneumonitis  Thick MAS  atelectasis, airway blockage, airleak syndrom

Risk Factors  Post-term pregnancy  Maternal hypertension  Abnormal fetal heart rate  Biophysical profile  6  Pre-eclampsia  Maternal diabetes mellitus  SGA  Chorioamnionitis

Clinical Presentation  Meconium staining of amniotic fluid before birth  Meconium staining of neonate after birth  Varying degree of respiratory distress and is likely to have a barrel chest with audible rales  Persistent pulmonary hypertension of the newborn  Pneumotorax (10%-20% infants with MAS )

Laboratory Studies  Complete blood count  Blood gas analysis  Blood culture

Chest X-Ray  Patchy areas of atelectasis alternating with areas of overinflation  Hyperinflation of the lung and flattening of the diaphragm

Management Prenatal management  Identification of high-risk pregnancy  Monitoring of fetal heart rate during labor

Delivery room management  Placed under radiant warmer  suction the hypopharinx to clear any residual meconium  Depressed infants (depressed respiration, HR < 100 beat / min, poor muscle tone  tracheal visualization and suctioning should be performed …management

General management  Empty the stomach contents to avoid further aspiration  Correction of metabolic abnormalities e.g. hypoxia, acidosis, hypoglycemia, hypocalcemia and hypothermia  Surveillance for end organ hypoxic/ischemic damage (brain, kidney, heart and liver) …management

Respiratory management  Frequent suction and chest vibration  Pulmonary toilet to remove residual meconium if intubated  Antibiotic coverage  Ventilatory support  ECMO …management

Prognosis  Mortality rate may be as high as 50%.  Survivors may suffer from bronchopulmonary dysplasia and neurologic sequelae.

Air Leak Syndromes Definition  Comprise a spectrum of diseases with the same underlying pathophysiology  Overdistension of alveolar sacs or terminal airways leads to disruption of airway integrity, resulting in dissection of air into surrounding spaces

Incidence  Most common in neonates with lung disease who are on ventilatory support but can also occur spontaneously  The more severe the lung disease, the higher the incidence of pulmonary air leak

Risk Factors  Spontaneous 0.5%  Ventilatory support 15-20%  CPAP 5%  Meconium staining / aspiration  Surfactant therapy  Vigorous resuscitation (bag ventilation)

Clinical Manifestation  Respiratory distress or sudden deterioration of clinical course with alteration of vital signs and worsening of blood gases.  Asymmetry of thorax is present in unilateral cases.

Investigations  The definitive diagnosis of all air leak syndromes is made radiographically by an A-P chest X- ray film and a lateral film.

Management General  Avoid ventilators  Careful use of manual bag ventilation Specific  Decompression of air leak according to the type.  Do not needle the chest

Congenital and Postnatal Pneumonia  Developing countries  pneumonia > 50% cases of respiratory distress  Term and post term  primary pneumonia because of prenatal aspiration due to fetal hypoxia as a result of placental disfunction  Preterm  postnatal pneumonia as consequence os septicemia, aspiration of feeds and ventilation for respiratory failure Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Clinical Manifestation  Tachipnea, respiratory distress with subcostal retractions, expiratory grunt and cyanosis  Lethargy, poor feeding, jaundice, apneic attacks, temperature instability  Cough  rare in newborn baby Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Management Supportive treatment should be provided  Thermoneutral environment  NPO  IV fluids given  peripheral vein  Oxygen given to relieve cyanosis  Antibiotics started Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Congenital Pneumonia  PROM > 24 hours, foul smelling liquor, peripartal fever, prolonged / difficult delivery, single or multiple unclean vaginal examination  Respiratory distress  soon after birth / during first 24 hours  Auscultation  non spesific Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

X-ray- Congenital Pneumonia

Nosocomial Pneumonia  Risk factor: Ventilated neonates : Preterm neonates  Prevention: Hand wash : Use of disposables : Infection control measures  Antibiotics: Usually require higher antibiotics Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Respiratory Distress in a Neonate with Asphyxia  Myocardial dysfunction  Cerebral edema  Asphyxial lung injury  Metabolic acidosis  Persistent pulmonary hypertension Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Persistent Pulmonary Hypertension of the Newborn  Causes Primary Secondary: MAS, asphyxia, sepsis  Management Severe respiratory distress needing ventilatory support, pulmonary vasodilators Poor prognosis Deorari, A. RD in a newborn baby. Teaching aids on newborn care. NNF. India. 2005

Congenital Heart Disease  May present with cyanosis and heart failure  CHD and pulmonary disease can coexist  Differentiation between heart and lung disease are cumulative Aly H, Pediatrics in Review 2004;25:

Clinical Manifestation  Visible hyperactive precordial impulse  Gallop rhythm  Poor capillary refill  Weak pulse  Decreased/delayed pulse in lower extremities  Hepatomegaly  Abnormal vascularity or cardiomegaly on CXR Aly H, Pediatrics in Review 2004;25:

 Single second heart sound  Usually do not have hypercapnia unless associated with lung disease  Do not present with chest retraction, but tachypnea is common  Oxygen saturation is decreased  Hyperoxygenation test will not produced significant increase in PaO 2 in most infants who have cyanotic CHD …clinical manifestation Aly H, Pediatrics in Review 2004;25:

Cyanotic Heart Disease Pulmonary Disease History  Previous sibling who has CHD  Diagnosis of CHD by prenatal ultrasonography  Maternal fever  Meconium stained amniotic fluid  Preterm fluid Physical findings  Cyanosis  Gallop rhythm  Single record heart sound  Large liver  Mild respiratory distress  Cyanosis  Severe retraction  Split second heart sound  Fever Arterial Blood Gases  Normal or decreased PCO 2  Decreased PO 2  Increased PCO 2  Decreased PO 2

Cyanotic Heart Disease Pulmonary Disease Chest Radiograph  Increased heart size  Decreased pulmonary vascularity (except in transposition of the great vessels and total anomalous pulmonary venous return)  Normal heart size  Abnormal pulmonary parenchyma, such as : Total whiteout or patches of consolidation in pneumonia Fluid in the fissures in TTN Ground glass appearance in HMD Hyperoxyg enation test Echocardio graphy  PaO 2 < 150 mm Hg  Abnormal heart or vessels  PaO 2 > 150 mm Hg (except in severe PPHN)  Normal heart and vessels

Respiratory Distress Needing Referral  RDS (HMD)  MAS  Surgical or cardiac cause  PPHN  Severe or worsening distress

Apnea Definition  Cessation of respiration accompanied by bradycardia and / or cyanosis for more than 20 seconds

Incidence  50-60% of preterm neonates have evidence of apnea (35% with central apnea, 5-10% with obstructive apnea, and 15-20% with mixed apnea) Aly H, Pediatrics in Review 2004;25:

Risk Factor Pathological apnea Hypothermia Hypoglycemia Anemia Hypovolemia Aspiration NEC / Distension  Cardiac disease  Lung disease  Gastro intestinal reflux  Airway obstruction  Infection, meningitis  Neurological disorders Aly H, Pediatrics in Review 2004;25:

Investigations  Monitoring at-risk neonates less than 32 weeks gestational age  Evaluate for a possible underlying cause  Laboratory studies should include a CBC, blood gas analysis, serum glucose, electrolyte, and calcium levels  Radiologic studies if chest disease is suspected Aly H, Pediatrics in Review 2004;25:

Management General therapy  Perform tactile stimulation  CPAP in recurrent and prolonged apnea  Pharmacological therapy (caffeine or theophylline) may be required Aly H, Pediatrics in Review 2004;25:

…management Specific therapy  Treatment of the cause, if identified, eg. treatment of sepsis, hypoglycemia, anemia, and electrolyte abnormalities Aly H, Pediatrics in Review 2004;25:

Prognosis  In most neonates apnea resolves without the occurrence of long-term deficiencies Aly H, Pediatrics in Review 2004;25:

Summary 1. Evaluate the severity of respiratory distress using the Down's Score 2. Identify common neonatal respiratory disorders, including: Transient Tachypnea of the Newborn (TTN) Respiratory Distress Syndrome (RDS) Meconium Aspiration Syndrome (MAS) Air leak syndromes Apnea Pneumonia

…summary 3. Identify the risk factors, clinical presentation, required laboratory and radiological investigations, and management of TTN, RDS, MAS, Air Leak Syndromes, Pneumonia, Apnea

< Prophylaxis Rescue Consider if no antenatal steroids, lung immaturity, male sex, and need for intubation in resuscitation When needing IPPV and > % oxygen Especially if no antenatal steroids, known lung immaturity, male sex and need for intubation in resuscitation Gestational Age (Weeks) Guidelines for early management of RDS (Advances in Perinatal Medicine, 1997, )