Acute Care Pediatric Nurse Practitioner Review Course 2020 Andrea Kline Tilford PhD, CPNP‐AC/PC, FCCM C.S. Mott Children’s Hospital Ann Arbor, Michigan ©202 0 Disclosures • I have no financial relationships to disclose • I will not discuss investigational drug use ©202 0 Objectives • Discuss general principles of pediatric respiratory physiology • Discuss the presentation and evaluation of common pediatric respiratory diseases • Identify appropriate management strategies for common pediatric respiratory diseases ©202 0 Basic Anatomy • Upper Airway • Supraglottic (nose, nasopharynx, epiglottis) • Glottis (vocal cords, subglottic area, cervical trachea) • Humidifies inhaled gases • Warms inhaled gas • Site of most resistance to airflow • Conducting airways (dead space) • Lower airways • Thoracic trachea, bronchi, bronchioles and alveoli (gas exchange) ©202 0 Anatomical Considerations in Children • Pediatrics • Small mouth • Large tongue • In relation to mandible • Floppy epiglottis (infants) • Large occiput • Infants are obligate nose breathers (until ~ 6 months of age) • Cricoid ring narrowest portion of airway in infants and young children ©202 0 Bronchus • Bifurcates into right and left bronchus • RIGHT side generally more straight and more likely to be site of aspiration www.med.umich.edu ©202 0 Alveoli • Continue to multiply until ~ 8 years of age Covered in capillaries Site of gas exchange oac.med.jhmi.edu ©202 0 Basic Physiology • Goal of respiration = Oxygen in and carbon dioxide out • Oxygen ʻinʼ • For cell use • Carbon dioxide ʻoutʼ • Produced by cells ©202 0 Gas Exchange • Inhalation • Active; requires contraction of several muscles (e.g. diaphragm, intercostals) • Exhalation • Passive • Relaxation of intercostals and diaphragm, return of rib cage, diaphragm, and sternum to resting position, increases pressure in lungs and air is exhaled **PEARL: Some conditions, such as status asthmaticus, interfere with passive exhalation. Physical exam demonstrates forced and prolonged exhalation phase. ©202 0 Impairment of Respiration • Under neural and chemical control • Hypoventilation should always raise concern for neuronal anomaly (e.g. drug effect, underlying intracranial process, others) • Hyperventilation often caused by conditions outside the lung (metabolic acidosis, neurologic process, anxiety) ©202 0 COMMON PEDIATRIC RESPIRATORY DISEASES ©202 0 Bronchiolitis • Definition • Acute inflammatory disease of the lower respiratory tract • Etiology • Many different viral agents • Respiratory syncytial virus (RSV) and influenza account for most cases when a specific agent can be identified • Other common agents: Rhinovirus, adenovirus, parainfluenza, human metapneumovirus • Incidence • Peaks in winter months, though common fall – spring • Risk Factors for severe disease • Prematurity, cardiopulmonary disease, infants < 6 months of age, immunodeficiency www.nlm.nih.gov ©202 0 Bronchiolitis • Pathophysiology • Inflammatory disease of lower respiratory tract • Also, a disease of lung parenchyma • Clinical Manifestations • Rhinorrhea, congestion • Tachypnea, increased work of breathing • Hypoxia Flat diaphragms • Fever • Wheezing; prolonged exhalation • *Typically begins as upper respiratory infection that spreads to lower airways in first few days of illness • Diagnostic Evaluation • History and physical; diagnostic in most cases • Chest radiograph (Commonly demonstrates hyperexpansion, patchy atelectasis, peribronchial thickening) • Viral studies are supportive (RSV, influenza, etc) • Pulse oximetry www.surgery.usc.edu Bronchiolitis Chest Xray Peribronchial Bronchial wall thickening thickening www.learningradiology.com ©202 0 Bronchiolitis • Management • Supportive care • Oxygen • Additional respiratory maneuvers, if indicated • Routine use of bronchodilators, racemic epinephrine, and corticosteroids are NOT recommended; AAP guidelines • Prevention • Hand washing • Palivizumab®, as indicated http://pediatrics.aappublications.org/content/early/2014/10/21/peds.2014-2742 ©202 0 Laryngotracheobronchitis (Croup) • Definition • Infection involving subglottic airway, larynx, trachea, and bronchi • Etiology • Most commonly caused by parainfluenza type 1 and 2 • Less commonly caused by respiratory syncytial virus (RSV), adenovirus, influenza types A and B, parainfluenza type 3 • Infrequently caused by Mycoplasma pneumoniae • Incidence • Most commonly affects children 3 months ‐ 5 years of age • Some children are at risk for recurrent episodes • Northern hemisphere; most common between October and March ©202 0 Croup • Pathophysiology • Mucosal airway edema from infectious etiology • Subsequent epithelial necrosis • Decreased airway diameter and increased resistance to airflow • Clinical Manifestations • ʻBarkyʼcough • Stridor • Hoarseness • Increased work of breathing • Wheezing/prolonged expiratory phase • Frequently begins 12‐ 48 hours after non‐specific upper respiratory tract symptoms • Typically, symptoms are worse at night ©202 0 Croup • Evaluation • Westley Croup score or other scoring tool may be used • Stridor, retractions, air entry, cyanosis, level of consciousness • Diagnosis • Generally based on history and examination • Viral studies may be sent to identify the pathogen • Consider lateral neck films (e.g. “Steeple sign”) • Consider chest radiograph; may be obtained to evaluate for superimposed bacterial infection and/or narrowing of subglottic area ©202 0 Croup •Management • Humidified or cool mist air/gas • Steroids • Dexamethasone 0.6 mg/kg IV/IM • Oxygen and respiratory maneuvers, as needed • Consider aerosolized racemic epinephrine • Consider heliox (light gas, improves laminar flow) • Intravenous fluids, if dehydrated • Otolaryngology consult if no improvement with standard therapy ©202 0 Asthma Definition • Asthma • Chronic reversible disorder resulting in inflammation, bronchoconstriction, airway hyperresponsiveness • Characterized by episodes of cough, wheeze, dyspnea, chest tightness • Status Asthmaticus • Progressively worsening bronchospasm/airflow obstruction unresponsive to standard therapy Incidence • Most common chronic illness in childhood Etiology • Triggers • Extrinsic: Allergic/immunologic factors • Intrinsic: Infectious • Exercise induced www.uhn.ca ©202 0 Asthma • Severity Classification • Intermittent, mild persistent, moderate persistent, severe persistent • See National Heart, Lung, Blood Institute Guidelines for more information and the ʻGuidelines for the Diagnosis and Management of Asthmaʼ at: http://www.nhlbi.nih.gov/guidelines/asthma/ ©202 0 Status Asthmaticus • Symptoms • Cough, especially at night • Tachypnea • Shortness of breath • Wheezing, forced and prolonged expiratory phase • Accessory muscle use • Tachycardia • Hypoxia • Pulsus paradoxus (moderate/severe exacerbations) • *Fever, if associated with infectious trigger • Diagnosis • History and physical exam • Chest radiograph: Hyperinflation, flattened diaphragms, peribronchial thickening, narrowed cardiac silhouette • Additional studies (e.g. arterial blood gas, lactate, electrolytes may be helpful in moderate/severe cases) www.pedsccm.wustl.edu ©202 0 Pulsus Paradoxus ©202 0 Status Asthmaticus • When following arterial blood gases or other carbon dioxide measurements, anticipate hypocarbia when compensating well for exacerbation • A normal or rising carbon dioxide measurement is worrisome ©202 0 Status Asthmaticus Hyperinflation, narrowed cardiac silhouette ©202 0 Status Asthmaticus Management • Inhaled Beta2 agonists (albuterol, levalbuterol) • Bronchial smooth muscle relaxation • Reduce antigen induced histamine release • Increase mucociliary transport • Intermittent dosing (MDI or nebulized); typically every 20 minutes for one hour. Continuous for refractory exacerbation • Corticosteroids • Decreases inflammation associated with chronic and acute airway inflammation • May be given intravenously or enterally • 2‐4 hours to take effect • Therapy > 5‐7 days requires taper ©202 0 Status Asthmaticus Management – Continued •Anticholinergics (e.g. ipratropium bromide) • Promotes bronchodilation • Used most frequently in the Emergency Department to prevent hospitalization •Admission criteria • Symptoms after observation for 60 minutes • Oxygen requirement • Short acting beta agonists > every 2‐3 hours • Prior intensive care unit admissions ©202 0 Status Asthmaticus Adjunctive Therapies • Magnesium sulfate • Physiologic calcium antagonist; causes smooth muscle relaxation • May be administered continuously or intermittently, IV • Most common adverse reaction is hypotension • Intravenous beta agonist (e.g Terbutaline) • Bolus, +/‐ continuous infusion • ECG monitoring • Methylxanthines (e.g aminophylline, theophylline) • Promotes smooth muscle relaxation through unknown mechanism • Narrow therapeutic index; requires serum drug level monitoring • High side effect profile (nausea, vomiting, seizures, abdominal discomfort) ©202 0 Status Asthmaticus Adjunctive Therapies ‐ Continued •Non‐Invasive ventilation •Heliox • Low density gas • Promotes laminar flow • Facilitates delivery of oxygen and aerosolized medications Turbulent flow Laminar flow •Invasive ventilation • Use with caution Risk for air leak syndromes • Allow permissive hypercapnia • May require muscle relaxation ©202 0 PEARL: Ketamine typically used for induction in asthmatics requiring intubation due to its bronchodilatory effects. ©202 0 Pertussis Background •Commonly known as ʻwhooping coughʼ •Making a comeback; immunity does not appear to be permanent Etiology •Bordetella pertussis;