Respirology Flashcards
Describe the pathophysiology of asthma
Allergen taking by antigen presenting cell to CD4 Th2 cell -> secretion of IL4 which activates IgE -> IgE attaches to Fc receptor on mast cell -> subsequent exposure of allergen results in mast cell degranulation and release of inflammatory cytokines -> vascular permeability, inflammation, bronchospasm, and airway hyperesponsiveness -> chronic have eosinophils that cause edema, smooth muscle contraction and goblet cell activation
What are some risk factors for asthma?
History of atopy
Urban area
History of bronchiolitis
History of maternal smoke exposure
Discuss the differences between intermittent and chronic asthma
Intermittent: due to small airways where any airway inflammation results in further narrowing and wheezing. Usually only have symptoms with colds and they improve with time
Chronic: due to atopic mechanism following respiratory syncytial virus infection leading to IgE. Have chronic symptoms with exacerbations due to allergens, viral infections or exercise
This the possible investigations for asthma in children
<6 must due therapeutic trial if are having prolonged wheezing or cough with colds
>6 can do pulmonary function testing
>8 can do methacholine challenge
List the common inhaled corticosteroids and their doses for mild, moderate and severe
Fluticasone: 100mcgBID, 125mcgBID, 250mcgBID
Beclamethasone: 100BID, 200BID, 400BID
Budesonide: 200BID, 200TID, 400BID
Take 1-6 weeks before have any affect
Only 15% reach the lungs
Can decrease doses by 25% if are able to handle triggers
Side effects: thrush, Dysphoria, hypothalamic-pituitary axis dysregulation, grow 1cm less in first year but usually make it up
Discuss leukotriene receptor blockers for the treatment of asthma
Block the leukotriene receptor, so are useful with viral URTI as they receptors are more active. Onset in 1 day
Montelukast: 2-5 4mgqHs, 6-14 5mg, >14 10mg
Discuss the use and effectiveness of bronchodilators for asthma
Short Acting Beta2 Agonists: Salbutamol
- QID at onset of colds
- q4h during exacerbations
- before exercise
Long Acting Beta2 Agonists: Salmeterol or Formoterol
- onset within 5-30 minutes and last for 6-12 hours
- addition of long acting improves symptom control and lung function, however must use with inhaled corticosteroid or have increased risk of life-threatening exacerbation
Side effects: tremor, headaches, palpitations
What are two combination inhalers
Advair: Fluticasone and Salmeterol (>6yo)
Symbicort: Budenoside and Formoterol (>12yo)
What is the pathophysiology of cystic fibrosis?
Autosomal recessive inheritance of CFTR gene -> results in Cl not being transported out of the cell -> results in no gradient for Na and water to cross -> increase viscosity of secretions leading to obstruction and mucostasis
List some of the sequelae from cystic fibrosis
Respiratory tract:
- mucostasis results in chronic infections and rhinosinusitis and nasal polyps
- mucostasis results in mucous plugging and bacterial pneumonia (staph -> h flu -> pseudomonas -> nosocomial)
- bronchiectasis due to chronic lung scarring and fibrosis
GI:
- mucostasis leads to pancreatic insufficiency and malnutrition, steatorrhea and failure to thrive
- chronic obstruction of pancreas leads to dysfunction and diabetes
- mucostasis can block bowel leading to meconium ileus, constipation, obstruction or intussusception
- mucostasis block biliary tree leading to liver cirrhosis
Reproductive
- obstruction of vas deferens leading to infertility
- thickened cervical mucous and infertility
List some of the investigations for cystic fibrosis
Diagnostic: - heel prick for highly immunoreactive trypsinogen - sweat chloride test - CFTR gene mutation Pulmonary function test - obstructive disease (low FEV1, low FEV1/FVC, scooped curve) Chest X-ray - hyperinflation - tram tracks from bronchiectasis - increased pulmonary markings
Discuss the management of cystic fibrosis
Chest physiotherapy for secretions (percussion, positive expiratory pressure)
SABA
Inhaled dornase alfa to reduce viscosity of mucous
Inhaled tobramycin for pseudomonas infection
Nutritional counselling and pancreatic enzyme supplementation
Oral or IV antibiotic for exacerbation
Discuss three different types of apnea in children
Central: failure of medulla to coordinate breathing movements
Obstructive: obstruction of airway resulting in failure to ventilate
Mixed: central and obstructive
Discuss the presentation and management of pertussis
Organism:
- Bordetella pertussis
Phases:
Catarrhal phase:
- 1 week of mild URTI symptoms
Paroxysmal phase:
- 6 weeks of paroxysmal coughing with inspiratory whoop and post-tussive vomiting
Convalescent phase:
- 6-10 weeks of gradual decrease in cough (prolonged due to bacteria necrosis to cough receptor)
Investigations:
- in those with >=2 weeks of cough with at least one of: paroxysmal, post-tussive vomiting, cough with inspiratory whoop must perform nasopharyngeal aspirate
- apnea <1
- lymphocytosis
Management:
- isolation for 5 days if receive treatment or after >21 days of symptoms
- Antibiotics if symptom onset less than 3 weeks (usually only prophylactic):
- Azithromycin PO x5, or Clarithromycin PO x7
- Erythromycin PO x7-10
Discuss the presentation and management of tracheitis
Organism: - Staph aureus - group A strep - h flu Presentation: - fever - brassy cough - worsening stridor - large amount of purulent discharge Treatment: - secure airway - cefuroxime
Discuss the presentation and management of foreign body aspiration
Demographics: - between 6 months and 4 years Presentation: Upper airway: respiratory distress Lower airway: triad of cough, wheeze, decreased breath sounds Investigations: - x-ray Treatment: - ABC - removal by bronchscoscopy
Discuss the presentation and management of bronchiolitis
Demographics: - <2yo - between December to March Organism: - RSV resulting in edema and mucous production in bronchioles and bronchospasm Presentation: - begin as URTI - wheezing - respiratory distress - improves after 1-2 weeks Management: - Admission to hospital if: <7weeks, <34 weeks premature, HR>180, RR>80, O2<92 - Supportive: - nasal suction, - positive pressure ventilation - hydration - bronchodilator with epinephrine for outpatients
Discuss the presentation and management of pneumonia in children
Organism:
Viral: RSV, influenza
bacterial: strep pneumonia, group A strep, staph, mycoplasma and chlamydia (last two common in school age)
Presentation:
Bacterial: abrupt onset of fever, chills, productive cough, with decreased breath sounds and crackles
Viral: gradual onset with low fever and URTI signs and bronchial breath sounds
Investigations:
- CXR showing consolidation and interstitial pattern (viral)
Management:
- Admission if: failure of outpatient therapy, respiratory compromise, pleural effusion, dehydration
- Antibiotics: Amoxicillin if community acquired, ampicillin and then amoxicillin if community acquired inpatient, severe community acquired require IV ceftriaxone
List the differential diagnosis for a wheeze
Acute:
- inflammatory: asthma
- infectious: croup, bronchitis, bronchiolitis
- trauma: foreign body
Chronic:
- structural: tracheobronchomalaecia, tumour,
- functional: asthma, GERD, swallowing dysfunction, cystic fibrosis
Discuss the differential for a cough
Acute: <3 weeks
- infectious: viral (URTI, pneumonia, croup), bacterial (pneumonia, pertussis)
- non-infectious: asthma, bronchiectasis
Sub-acute: 3-6 weeks
- post-infectious
- any acute or chronic condition
Chronic: >6 weeks
- inflammation: asthma, post-nasal drip, rhinitis
- infectious: recurrent viral infections, bronchitis
- trauma: foreign body
- cardiac: cardiomyopathy, ACE inhibitors
- GERD
Discuss the presentation and management of an Acute Life-Threatening Event in Children
Definition:
- is an acute change in infant’s breathing, appearence or behaviour that is frightening to the parent which may include: apnea, color change, change in muscle tone, or choking
Etiology:
- Normal: choking, irregular breathing in REM sleep, respiratory pauses
- Acute: respiratory infection, meningitis, volvulus, toxin ingestion, child-abuse]
- Chronic: GERD, congenital heart disease, abnormalities in the airway, seizure, CNS hemorrhage, central apnea
Management:
- in-hospital observation for 24hrs with continuous monitoring to exam for another event
- no monitoring necessary if non-concerning event associated with feeding
- caregiver can be provided with CPR training, proper infant sleep techniques and saline nose drops
What are the maternal and infant risk factors for sudden infant death syndrome?
Maternal: Modifiable: - smoking or alcohol use during pregnancy - alcohol or recreational drugs in antenatal period - maternal nutritional deficiency in antenatal - late to no prenatal care - preterm Nonmodifiable: - fetal growth restriction - low SES - maternal age <20, single - intrauterine hypoxia Infant: Modifiable: - exposure to second hand smoke - no pacifier, prone or or side sleeping - bed sharing with patient - soft sleeping surface or bedding - sleeping in car seats - thermal stress - growth failure Nonmodifiable: - premature - age 2-4 months - African-American or Native - recent febrile illness
List some protective factors for sudden infant death syndrome
- room sharing
- pacifier
- breast feeding
- fan
- immunization
Discuss signs of respiratory distress
General: - cyanosis - diaphoresis - confusion Respiratory mechanics: - retractions (intercostal, tracheal tug) - nasal flare - head bobbing - stridor - grunting - abdominal breathing
Discuss the presentation and management of laryngeomalacia
Pathophysiology:
- collapse of tissue above airway from short aryepiglotic folds
- arternoid prolapse
- omega-shaped epiglottis
Symptoms:
- Presents 2 weeks after birth
- inspiratory stridor that is intermittent and increases with feeding, normal cry, noisy sleep
Treatment:
- surveillance
- surgical if apnea, failure to thrive, difficulty feeding
Discuss the presentation and management of unilateral and bilateral vocal cord paralysis
Unilateral:
- no stridor and able to maintain airway, voice changes
Bilateral:
- significant inspiratory stridor and respiratory distress resulting in tracheostomy
Discuss the presentation and treatment of tracheomalacia
Presentation: - expiratory wheeze - apnea - feeding difficulties and failure to thrive Investigations: - bronchoscopy showing vascular rings
Discuss the presentation and management of retropharyngeal abscess
Demographics: - children <2 with antecedent URTI Symptoms: - stridor - muffled voice - gurgling - odynophagia - fever Signs: - mass in lateral neck - painful hyper extension Investigation: - x-ray showing enlarged retropharyngeal space Treatment: - Group A beta-hemolytic strep so receive penicillin following I/D
Discuss the presentation and treatment of epiglotittis
Demographics: - 2-12 year olds - haemophilus influenza type B Symptoms: - stridor - muffled voice - hoarseness - odynophagia leading to drooling - leaning forward - fever Investigations: - x-ray showing thumb sign of epiglotis Treatment: - Maintain airway and cefuroxime
Discuss the presentation and management of croup (laryngeotracheobronchitis)
Demographics: - 3 months to 5 years, - Spring and Fall Organism: - para-influenza 1&3, - influenze A&B, - RSV Symptoms: - stridor - hoarseness - barky cough - rhinitis - worse at night Investigation: - x-ray show steeple sign Treatment: - oxygen - dexamethasone PO 0.6mg/kg, - nebulized epinephrine
