Respiratory Flashcards
Stages of lung development
- Embryonic (3-7 wks)
- Pseudoglandular (5-17 wks)
- Canalicular (16-26 wks, surfactant secreting)
- Saccular (26-36 wks)
- Alveolar (36 wks to 3-8 yo)
Describe laryngomalacia
- Benign congenital extrathoracic airway disorder
- Underdeveloped cartilaginous support of supraglottic structures
Clinical presentation of laryngomalacia
Intermittent to persistent stridor in first 6 wks of life
Stridor caused by laryngomalacia worsens:
- In supine position
- Increased activity (crying)
- With URI
- During feedings
What contributes to the inspiratory obstruction in laryngomalacia?
Approximation of posterior edges of the epiglottis
Treatment and prognosis of laryngomalacia
- Improves with age
- Surgical epiglottoplasty if FTT, obstructive sleep apnea or resp insufficiency
When is surgical epiglottoplasty indicated in laryngomalacia?
- Failure to thrive
- Obstructive sleep apnea
- Resp insufficiency or severe dyspnea
Describe congenital vocal cord paralysis
- 15-20% of laryngeal anomalies
- Equal in both genders
- MC idiopathic etiology
Describe subglottic hemangiomas
- Congenital extrathoracic airway disorder
- Females 2:1
- Asymptomatic at birth w/progressive croup
How do subglottic hemangiomas present?
Asymptomatic at birth with progressive croup
Describe viral croup
- Parainfluenza
- Subglottic edema w/upper airway obstruction
- Croup (barking) cough
- Inspiratory stridor
- Fall and winter months
Clinical presentation of viral croup
- Afebrile or low grade fever
- Inspiratory stridor
- Barking cough (worse at night)
- Steeple sign on CXR
Treatment of viral croup
- Cool, moist air
- Racemic epi via nebulizer
- Dexamethasone
Clinical presentation of epiglottitis
- High fever, toxic appearance
- Drooling and dysphagia
- Muffled voice
- Inspiratory retractions
- Soft stridor
- Thumbprint sign on x-ray
Etiology of epiglottitis
- Hemophilus influenze type B (HIB)
- Now only in unimmunized children
Treatment of epiglottitis
- Immediate ET intubation
- Sedation for intubation/extubation is difficult to manage
- IV abx (ceftriaxone)
When is extubation performed in epiglottitis?
After visual inspection of epiglottitis (usually 24-48 hrs)
What is bacterial tracheitis?
- Pseudomembranous croup
- Severe, life threatening
- S. aureus MC
Clinical presentation of bacterial tracheitis
- Early symptoms are consistent with viral croup
- Subsequent increasing fever, toxicity, progressive airway obstruction
Treatment of bacterial tracheitis
- Debridement of airway w/intubation
- IV abx for H flu
- Longer intubation than for epiglottitis
Which requires longer intubation - epiglottitis or bacterial tracheitis?
Bacterial tracheitis
Cause of vocal cord paralysis?
Injury to phrenic nerve
- Difficult delivery
- Neck/thoracic surgery
- Trauma, mediastinal masses, CNS disease
Clinical presentation of vocal cord paralysis
- Hoarseness
- Aspiration
- High pitched stridor
What is the narrowest part of neonate or infant’s airway?
Subglottis
MC cause of subglottic stenosis
ET intubation
Treatment of subglottic stenosis
May require tracheostomy
Cause of laryngeal papillomatosis
HPV 6, 11, 16
Age of onset of laryngeal papillomatosis
Usually 2-4 yo
How to prevent laryngeal papillomatosis?
HPV vaccine
Treatment of laryngeal papillomatosis
- Direct surgical resection
- Spontaneous remissions do occur
Describe cartilage in infant airway
Softer, more pliable, can collapse easier
Describe tracheomalacia
- Cartilage in infant airway is softer and can collapse
- Cough, stridor, wheezing
What is diagnostic of tracheomalacia?
Tracheal collapse of more than 50% during inspiration
Congenital tracheomalacia may be a/w what?
Developmental abnormalities (tracheoesophageal fistula, vascular ring, etc.)
Treatment of tracheomalacia
May vary:
- Observation
- PPV (positive pressure ventilation)
- Surgery
How do vascular rings and slings present?
In infancy with stridor, wheeze, croupy cough
Where do bronchogenic cysts typically occur?
Middle mediastinum near carina and major bronchi
How are bronchogenic cysts developed?
Abnormal budding of primitive foregut
Treatment of bronchogenic cysts
Surgical resection with pulmonary PT
CXR finding of bronchogenic cyst
Filling of retrosternal clear space on lateral view
Describe foreign body aspiration
- Actual event RARELY seen
- Children 6 mo to 4 yo at highest risk
Clinical presentation of upper airway FB aspiration
Sudden onset cough and dysphonia
Clinical presentation of lower airway FB aspiration
Sudden onset cough, possible persistent cough or wheeze
Treatment of FB aspiration in the upper airway
- Allow spontaneous cough reflex first
- Otherwise, back blows per CPR
- NO finger sweeps
When is bronchoscopy indicated?
Any 2 of:
- History of possible aspiration
- Focal abnormal chest exam
- Abnormal CXR
How many people are carriers of CF?
1 in 40
Treatment of CF
- Pancreatic enzyme supplements
- High cal, protein and fat diet
- Multivitamins (ADEK)
- Salt supplement
- Airway clearance/hygiene
- Aggressive abx use
- Inhaled mucolytic agent
Prognosis of CF
Avg life expectancy 35 yo
What is Kartagener syndrome?
- Primary ciliary dyskinesia
- Ultra-structural defect of cilia demonstrated by electron microscopy
Clinical presentation of Kartagener syndrome
Situs inversus in 50% of pts
Situs inversus is found in 50% of pts with what condition?
Kartagener syndrome (primary ciliary dyskinesia)
Define bronchiectasis
Permanent dilation of the bronchi due to retained mucus and inflammation from chronic secretions
What does bronchiectasis look like on CXR?
Increased bronchovascular markings and areas of atelectasis with hyperinflation
Treatment of bronchiectasis
- Aggressive abx therapy
- Surgical resection of affected lung
Describe bronchiolitis obliterans
Partial or complete occlusion of bronchiole lumen by inflammatory and fibrous tissue
Causes of bronchiolitis obliterans
- Infections (esp adenovirus)
- Toxic gases
- CT disease
- SJS
What does congenital agenesis of one lung result in?
Mediastinal shift and compensatory growth of the remaining lung
What causes congenital lung hypoplasia?
Intrathoracic mass (e.g. diaphragmatic hernia)
CXR findings of lung agenesis and hypoplasia
Mediastinal, tracheal shift
Define pulmonary sequestration
- Nonfunctional pulm tissue
- Not communicating with tracheobronchial tree, blood supply from anomalous systemic arteries
Treatment of pulmonary sequestration
Surgical resection
Prevalence of HMD (RDS type 1)
5% in infants 35-36 wks EGA
50% in infants 26-28 wks EGA
MC bacterial source of pneumonia?
Strep pneumo
What are conditions that increase risk of invasive pneumococcal disease?
- Asplenia (functional or anatomic)
- Cochlear implant recipient
Clinical presentation of bordetella pertussis
Stages
- Catarrhal: 2 wks
- Paroxysmal: 2 or more wks
- Convalescent: wks to months (100 day cough)
MC community acquired pneumonia?
Mycoplasma pneumo
Clinical presentation of mycoplasma pneumonia
- Insidious onset
- Rales, bullous OM, sore throat
- CXR: interstitial or bronchopneumonic infiltrates
Describe mycobacterium tuberculosis
- Widespread, often fatal disease
- Isolated pulm parenchymal disease in 85% of cases (transmission common)
Who is MC affected by mycobacterium tuberculosis?
- Homeless
- AIDS
- Residents in jails/nursing homes
- Drug use
- Healthcare workers
Most pneumonias in children are:
VIRAL
- RSV
- Parainfluenza
- Influenza A and B
CXR findings of viral pneumonia in children
- Perihilar streaking
- Increased interstitial markings
Define bronchiolitis
- Lower airway viral infection in children under 2 yo
- RSV MC pathogen
Clinical presentation of bronchiolitis
- Poor feedings
- Disrupted sleep
- Fever, rhinorrhea, cough
Underlying conditions that can influence bronchiolitis presentation
- Chronic lung disease (esp BPD)
- CF
- Congenital heart disease
- Immunodeficiency
How does aspiration pneumonia present?
- Variably: based on position when aspiration occurs
- Right side is MC (esp RUL if supine)
How does aspiration pneumonia MC present if it occurs while supine?
RUL
What is children’s interstitial lung disease syndrome (chILD)?
- Constellation of s/s rather than specific diagnosis
- Diagnosis requires certain criteria
How to diagnose children’s interstitial lung disease syndrome (chILD)?
3 of 5 criteria
- Impaired resp function symps
- Impaired gas exchange
- Diffuse infiltrates on imaging
- Presence of adventitious sounds
- Abnormal spirometry, PFTs, CO2 diffusion capacity
How is hypersensitivity pneumonitis MC caused?
-Exposure to wild or domestic birds (or their droppings)
-Inhalation of organic dust
(and presents as chILD)
Describe eosinophilic pneumonia
- Presents as chILD
- Notable for elevated eosinophil counts and high serum IgE
What do new pulmonary infiltrates in an immunocompromised patient represent?
- 1/3 to 1/2 may NOT be infection
- May be toxicity to chemoRT, hemorrhage, embolism, atelectasis
Pulmonary embolism in children?
- Probably underdiagnosed in acute respiratory distress in children
- Negative D-dimer is over 95% negative predictive value
Describe pulmonary edema
Excessive fluid in lungs due to:
- Increased pressure (cardiogenic)
- Increased permeability (primary RDS or noncardiogenic)
What is congenital pulmonary lymphangiectasia associated with?
Other congenital conditions
Types of scoliosis
- Congenital (vertebral anomalies and neuromuscular causes)
- Idiopathic (adolescents, females 5:1)
When should congenital scoliosis be considered?
When it presents pre-puberty
What does correction of pectus excavatum accomplish?
- Subjective improvement in cardiopulmonary function has been reported
- Mainly the treatment is based on cosmetic or psychological factors
Pectus carinatum may be a/w:
Mucopolysaccharidoses or congenital heart disease
Which congenital chest wall condition may be a/w mucopolysaccharidoses or congenital heart disease?
Pectus carinatum
Classifications of pectus carinatum
- Chicken breast (chondrogladiolar)
2. Pouter pigeon breast (chondromanubrial)
Describe eventration of the diaphragm
Striated muscles of diaphragm replaced by connective tissue
- Congenital (incomplete formation of diaphragm)
- Acquired (phrenic nerve injury)
Treatment of eventration of diaphragm
If resp symptoms persist 2-4 wks, the diaphragm is stabilized with surgical plication
Define transudative pleural effusion
Imbalance of hydrostatic and oncotic pressure (filtration exceeds reabsorption)
Define exudative pleural effusion
Inflammation of pleural surface w/increased capillary permeability
Pleural effusions are often associated with what condition?
Bacterial pneumonia
Define empyema
Grossly purulent pleural effusion
Treatment of empyema?
Abx (preferably directed by culture) and drainage of effusion
When is a chest tube indicated with pleural effusion?
If effusion present over 7 days (greater chance that the effusion is loculated)
Describe chylothorax in the newborn
Can be congenital OR due to birth trauma
Treatment of chylothorax
- Conservative w/spontaneous resolution
- If recurrent, ligation or sclerosis of thoracic duct
When is spontaneous PTX MC in newborns?
Birth trauma
PPV
What is an anterior/superior mediastinal mass most likely to be?
Thymus tissue
What is a middle mediastinal mass most likely to be?
Lymphomas
Reactive lymph node
What is a posterior mediastinal mass most likely to be?
Neural tissue
Which children have higher incidences of obstructive sleep apnea?
- Craniofacial abnormalities
- Neuropathies
- Use of hypnotics, sedatives, anticonvulsants
When is central sleep apnea in a child considered significant?
- If episodes over 20 seconds
- If associated bradycardia OR O2 desaturation
Treatment of sleep apnea in children
Adenotonsillectomy (50% may still have sleep apnea post-op)
Describe apparent life-threatening events (ATLEs)
- Observed apnea, color change, hypotonia, choking
- 50% remain unexplained
- Unclear association w/SIDS
Define SIDS
Sudden death of an infant under 1 yo which remains unexplained despite TEAR:
- Thorough case explanation
- Examination of death scene
- Autopsy
- Review of clinical history
Risk factor for SIDS?
Back to sleep - prone position may:
- Decrease arousal
- Rebreath exhaled gases
- Effects on ANS
