Respiratory Flashcards
Common organisms causing croup
Parainfluenza virus
Human metapneumovirus
RSV
Influenza
Common organisms causing bronchiolitis
RSV in 80% Human metapneumovirus Parainfluena Rhinovirus Adenovirus Mycoplasma pneumoniae
What is asthma?
Chronic inflammatory disease of airways where airway inflammation leads to airway oedema, and hyperactivity resulting in reversible bronchoconstriction
Management of acute asthma
Positioning Oxygen Salbutamol Ipratropium bromide Steroids (pred or hydrocortisone) IV magnesium sulphate IV salbutamol Theophylline IV adrenaline
What kind of drug is ipratropium bromide?
Anticholinergic
What kind of drug is salbutamol?
Beta 2 agonist
What is the purpose of ipratropium bromide in management of asthma?
Augments the action of the beta-2 agonists
What kind of drug is montelukast?
Leukotriene receptor antagonist
What are some examples of long acting beta-2 agonists?
Salmetero, eformoterol
When should a LABA not be used?
Children under 5 or as first line prevention
What is omalizumab?
Murine recombinant monoclonal antibody
What is the mechanism of action of omalizumab?
Blocks IgE which suppresses early- and late-phase allergic responses and sputum eosinophilia
What is the mechanism of action of tiotropium?
Long acting anticholinergic drug
What are the BTS guidelines for asthma management (non acute)?
- SABA
- Low dose inhaled steroid
- If >5: LABA, increase steroid, then LTRA
If <5: LTRA - Increase steroid again
- Regular oral steroid and refer to resp
What is the definition of bronchopulmonary dysplasia?
Oxygen requirement beyond 36 weeks post conceptual age
What is the mechanism of action of caffeine for neonates?
- Decreases CNS effects of adenosine
- Stimulates breathing by:
- Enhancing CO2 sensitivity
- Increasing diaphragmatic activity
- Increasing minute ventilation
What makes premature babies at risk of BPD?
- Premature antioxidant system
- Surfactant deficiency
- Very compliant chest wall
What is the pathophysiology of BPD?
- Developmental arrest of alveologenesis and vasculogenesis
- dysregulated angiogenesis
- Leads to large, simplified alveoli and dysmorphic lung vasculature
What is the prognosis for BPD?
50% rehospitalised in first 2 years
More likely to have hyper-reactive airways and respiratory tract infections
What is croup?
Viral laryngotracheobronchitis
Which organisms cause croup?
Parainfluenza
Influenza
RSV
Rhinovirus
In what age is croup commonest?
6 months to 5 years
Is croup more common in girls or boys?
Boys
What is the management for croup?
Steroids
Inhaled budesonide
Nebulised adrenaline
Intubate
Treatment for tuberculosis?
RIPE:
Rifampicin + isoniazid (6 months)
Pyrazinamide + ethambutol (2 months)
Side effects of rifampicin
Orange urine/tears
Hepatic enzyme induction
Abnormal LFTs
Side effects of isoniazid
Abnormal LFTs
Peripheral neuropathy
Side effects of pyrazinamide
Liver toxicity
Side effects of ethambutol
Visual disturbance
Which TB drug should be avoided in very young children?
Ethambutol
What drug can be given as prophylaxis for a neonate born to a mother with active TB?
Isoniazid
What are the 3 types of CCAM?
Type 1 - single or multiple large cysts
Type 2 - multiple small cysts
Type 3 - solid mass
What is a congenital lobar sequestration?
Mass of non-functional lung with abnormal communication with airway, usually supplied by systemic circulation
Which lobes of the lung are most commonly affected by congenital lobar sequestration?
Lower lobes, left
What are bronchogenic/duplication cysts?
Remnant of primitive foregut derived from abnormal tracheobronchial budding - they contain normal tracheal tissue filled with fluid
What is congenital lobar emphysema?
Overinflation of the lobe as a result of intrinsic deficiency of bronchial cartilage ± elastic tissue
Where does congenital lobar emphysema affect?
Rare in lower lobes - usually left upper or right middle/upper
How does congenital lobar emphysema present?
Asymptomatic
Respiratory distress in neonatal period
Chest asymmetry
Hyperresonance
How is congenital lobar emphysema managed?
Lobectomy if respiratory distress
Conservatively if mild symptoms
What is congenital lobar emphysema often associated with?
1:6 have a cardiac abnormality
What is Scimitar syndrome?
Hypoplastic right lung with anomalous venous drainage, usually to IVC or right atrium ± systemic collateral arterial supply
What is the scimitar sign?
Vertical line caused by the right upper lobe pulmonary vein running into the IVC
How does scimitar syndrome present?
Asymptomatic, or can lead to recurrent infections
How is scimitar syndrome managed?
Surgical correction for vascular abnormality
What is the incidence of CDH?
1:2500-3500 births
On which side is CDH more common?
Left
What is the prognosis of CDH?
20-40% mortality rate
What is the cause of alveolar proteinosis?
Uncertain; some relate to deficiency of surfactant-associated protein B, some to gm-csf
Lipid-laden type II pneumocystis desquamate into the alveolar spaces
What is the prognosis for alveolar proteinosis?
Almost universally fatal in infants, in older children lung lavage can help
What is congenital pulmonary lymphangiectasia?
Rare dilatation of pulmonary lymphatics leading to severe neonatal respiratory distress and pleural effusions
What is congenital pulmonary lymphangiectasia associated with?
Congenital cardiac disorders like obstructed venous drainage
What causes obliterative bronchiolitis?
Viral infection, often adenovirus or myoplasma
Less often measles, RSV, or lung or bone marrow transplant
What is the pathophysiology of obliterative bronchiolitis?
Severe widespread small airway obstruction eventually leading to pulmonary hypertension
What is the radiological appearance in obliterative bronchiolitis?
Patchy areas of air trapping (honeycomb), patchy pruning of vascular markings, hyper inflated lungs
What is the management of obliterative bronchiolitis?
In early stages may respond to bronchodilators or steroids, but often no treatment is successful
What can obliterative bronchiolitis progress to?
Swyer-James or Macleod syndrome of unilateral hyper lucent lung with diminished vascularity
What is the pathophysiology of haemosiderosis?
Repeated episodes of pulmonary haemorrhage lead to an accumulation of haemosiderin in the alveoli
What causes haemosiderosis?
Uncertain - some are associated with CMPA, some with Goodpasture syndrome
What are the symptoms of haemosiderosis?
Usually episodic fever, dyspnoea, wheeze ± haemoptysis
How is haemosiderosis diagnosed?
By finding haemosiderin-laden macrophages in a BAL
How is haemosiderosis managed?
Steroids
Hydroxychloroquine or other immunosuppressives, treat the anaemia and hypoxia
What is the pathophysiology of pulmonary hypertension?
Chronic hypoxia leads to pulmonary vasoconstriction and arterial wall change
What are the management options for pulmonary hypertension?
High oxygen Nitric oxide Sildenafil Prostacyclin Nifedipine
How is cystic fibrosis inherited?
Autosomal recessive - multiple mutations but most common is delta F508
What is the cause of cystic fibrosis?
Mutation affects cystic fibrosis transmembrane conductance regulator (CFTR), which is a cyclic AMP regulated chloride channel on the apical surface of epithelial cells which also inhibits the epithelial sodium channel. In CF, the respiratory epithelium therefore fails to secrete chloride ions (fails to absorb in the sweat gland, hence the high sweat chloride), and hyper absorbs sodium ions and hence H2O. Secretions are viscid and the airway surface is dehydrated.
What are the pathophysiological features of CF?
Dehydration of mucus and airway surface liquid
Disturbed mucociliary clearance
Increased risk of airway infection
Inflammation associated with progressive lung disease
What is the incidence of CF?
Carriers are 1:25, disease is in 1:2500 births of white babies
What is ABPA?
Complex hypersensitivity reaction in response to colonisation of airways with Aspergillus fumigatus
Who gets ABPA?
Almost exclusively people with asthma or CF
What is the pathophysiology of ABPA?
Mucoid impaction of bronchi
Eosinophilic pneumonia
Bronchocentric granulomatosis
What are the symptoms of ABPA?
Recurrent exacerbations of fever, malaise, expectoration of brownish mucus plugs, wheeze, rhinosinusitis
What is the management of ABPA?
Steroids
Antifungals e.g. itraconazole
Omalizumab may be useful if recurrent
How is ABPA diagnosed?
Establishing sensitisation to Aspergillus antigens
How is CF diagnosed?
Guthrie tests immune reactive trypsin, which will be high
Sweat test
Genetic testing
What is a diagnostic sweat test value?
> 60mmol/l chloride in at least 100mg sweat
How is primary ciliary dyskinesia inherited?
Autosomal recessive
How common is primary ciliary dyskinesia?
1:15,000 births
How does primary ciliary dyskinesia present?
Neonatal respiratory distress and rhinorrhoea Recurrent LRTIs Sinus disease Glue ear Male infertility and female subfertility
What other conditions can primary ciliary dyskinesia be associated with?
40% have dextrocardia ± abdominal situs inversus (Kartagener syndrome)
How is primary ciliary dyskinesia diagnosed?
Nasal brushing for ciliary beat frequency, assessment of beat coordination and structure
Low exhaled/nasal nitric oxide
Which genes are implicated in primary ciliary dyskinesia?
DNAI1 and DNAH5 - identified in 40% of families with PCD
What is the treatment for primary ciliary dyskinesia?
Physiotherapy
Antibiotics
ENT and hearing assessment
Genetic counselling
What is the incidence of OSA?
2%
What is the peak age for OSA?
2-8 years
What are the contributing factors to OSA?
Increased upper airway resistance
Decreased neuromuscular activation
Altered ventilatory control
Changed arousal thresholds
What are the features of OSA?
Repetitive collapse of the pharyngeal airway
Intermittent hypercarbic hypoxia
Recurrent transient arousal
How is OSA diagnosed?
Polysomnography
What are the symptoms of OSA?
Snoring, snorting
Sleep disturbance
Non-refreshing sleep
Daytime sleepiness
What are the surgical options for OSA?
Adenotonsillectomy
Mandibular distraction
Maxillomandibular advancement
Tracheostomy
What are the medical/conservative options for OSA?
Intranasal corticosteroids
Leukotriene antagonists
Weight loss
Ventilatory support
How common is choanal atresia?
1:60-70,000 births
What causes choanal atresia?
Failure of the breakdown of the bucconasal membrane, leading to complete obstruction of the nostril(s)
Which conditions are cleft lip and palate associated with?
Pierre Robin sequence
Stickler sydrome
Edwards syndrome
What cases a laryngeal cleft?
Failure of closure of the tracheo-oesophageal septum
What is the serious complication of laryngeal haemangioma?
Can bleed copiously with instrumentation - topical adrenaline can then be used
What causes tracheo oesophageal fistula?
Failure of normal development of the primitive foregut
