Respiratory Flashcards

Question

Cystic fibrosis -organisms-

Answer 1

**S.aureus 64% (most common)** - MSSA 52%, MRSA 19% (assoc decline FEV₁) - airway inflammation additive effect with P.aeruginosa **Pseudomonas** - hypoventilation/hypoxia which promotes biofilm and defect CFTR allow binding - assoc decline FEV₁/survival - conversion of P.aeruginosa to mucoid phenotype worse prognosis **Burkholderia cepacia 3%** - accelarated decline PFT/survival - highly resistant to multiple AB - lung transplant in infected assoc recurrent infection (CI) - treatment: bactrim, doxycycline, ceftazidime, meropenem **Haemophilus influenzae 20-30%**

Answer 2

**pathophysiology:** **_pulmonary_** _defect_: inability to secrete NaCl/water causes thick secretions and chronic infections and defects in FA metabolism increase arachidonic acid causing inflammation _colonisation_: S.aureus, P.aeruginosa, Burkholderia cepacia, H.influenzae, Stenotrophomonas maltophilia, Achromobacter, Non TB mycoplasma, Aspergillus _progression:_ chronic infection/neutrophils produce elastase and cause tissue destruction with air trapping/bronchiolitis/bronchitis/bronchiectasis **_GIT_** - impaired bile/pancreatic secretions with maldigestion/malabsorption - CF related DM - intestinal obstruction/intussusception/rectal prolapse **_skin_** - decreased NaCl absorption from skin

Answer 3

**incidence:** usually adolescence **pathophysiology:** 45% no bronchoconstriction and fall in lung function post exercise completion **causes:** - exercise induced larygeal dysfunction: F\>M, athletes, exertion/stress - vocal cord dysfunction - structural abnormality - ILD

Answer 4

**obstructive:** scooping of descending limb of curve on expiration only **restrictive:** narrow based curve on inspiration/expiration **variable intrathoracic obstruction:** expiratory defect - reduced FEF50%/FIF50% - eg. tracheomalacia, bronchogenic cysts, tumour **variable extrathoracic obstruction:** inspiratory defect - elevated FEF50%/FIF50% - eg. laryngomalacia, tracheomalacia, vocal cord defect **fixed upper airway obstruction:** reduced insp/exp flow - FEF50%/FIF50%=1 - eg. tracheal stenosis, goitre

Answer 5

**pathology:** chlamydia trachomatis\*\*, CMV, mycoplasma, ureaplasma urealyticum **transmission:** via genital tract - 30% of women carry C.trachomatic and \>50% vertical transmission **clinical:** onset 2 weeks- 4 months - inclusion conjunctivitis +/- pneumonia (no wheeze) **diagnosis:** - _serum:_ high eosinophils/IgG/IgM - CXR: hyperinflation with interstitial pulmonary infilatrates **treatment:** erythromycin

Answer 6

**incidence:** rare in children **etiology** **_idiopathic:_** - _acute interstitial pneumonia/diffuse alveolar damage_: acute/severe deterioration with high mortality - _non-specific interstitial pneumonia_: expansion of alveolar by dense infiltrates - _organising pneumonia:_ patchy areas or inflammation/pneumonia - _lymphocytic interstitial pneumonia_ **_ILD syndromes in infants_** - _neuroendocrine cell hyperplasia of infancy_: hyperinflation with air trapping - _follicular bronchitis/bronchiolitis_: airway inflammation - _pulmonary interstitial glycogenosis_ - _genetic abnormalities of surfactant production_ **clinical:** tachypnoea, creps, hypoxia, diffuse infiltrates, clubbing, wheeze (20%) **PFTS:** restrictive patterns

Answer 7

**cysts:** asymptomatic but can cause intermittent obstruction due to filling with air **atresia/stenosis:** - _type 1:_ supraglottic obstruction, absent vestule, subglottic stenosis - _type 2_: supraglottic obstruction - _type 3_: perforated membranes partially obstructs glottis (web) presenting with asphyxia **clefts:** failed fusion of posterior cartilage 6-7weeks - 1:10,000 M\>F onset 5 months and diagnosis 3 years - types 1-4 - presents with increased secretions, feeding issues, FTT\< wheeze/stridor/aspiration, RTI - assoc GORD, tracheomalacia, DD **subglottic haemangiomas:** - grow 12-18mths then stabilise + resolution of 50% by 5yr - beard distribution of facial haemangiomas assoc PHACE - treat propranolol **laryngeal papillomatosis** - multiple polypoid growths of VC by HPV 2-3yrs - obtained via birth canal - hoarse, breathy, resp distress, obstruction - surgery/tracheo but not treatable

Answer 8

**incidence:** most common cause laryngomalacia 50-75% **sex:** M\>F 3:1 **assoc other pathology 30%:** tracheomalacia, subglottic stenosis, VC palsy **pathophysiology:** surrounding structural malformation - 50% large floppy arytenoids, 25% floppy epiglottis, 25% short aryepiglottic folds - prolapse over larynx during inspiration **clinical:** stridor 2weeks- 18months, abnormal voice, resp distress, poor feeding, FTT - causes GORD due to increased intrathoracic pressure to overcome obstruction **investigation:** fluoroscopy, laryngoscopy/bronchoscopy **management:** - 99% conservation - surgery if severe

Answer 9

Salbutamol: 8 hours Salmeterol: 48 hours Ipratropium: 24 hours Theophylline: 12-48 hours Montelukast: 24 hours Antihistamine: 72 hours Nedocromil: 48 hours Glucocorticoid: 2-3 weeks

Answer 10

**pathophysiology:** necrosis of pulmonary parenchyma by infection **causes:** aspiration pneumonia, post tricuspid valve endocarditis (S.aureus), Lemierre's syndrome, pharyngitis **organisms:** - _usually anaerobes from mouth:_ peptostreptococcus, prevotella, bacteroides, fusobacterium - _others_: S.aureus, K.pneumonia, nocardia, fungi **clinical:** indolent symptoms weeks-months **CXR:** infiltrates with cavity +/- ring enhancement **diagnosis:** transtracheal/bronchoscopic aspirates (sputum contaminated) **treatment:** IV AB

Answer 11

**incidence:** most common form paediatric ILD **pathogenesis:** cause unknown ?EBV **2 patterns:** _perinatal HIV:_ 25-40% children by 2-3yrs - insidious onset cough, dyspnoea, clubbing - LN, HSM, salivary gland enlargement - hypergammaglobulinaemia - can spontaneously resolve or progress to respiratory failure _others:_ idiopathic, AI associated - tachypnoea, cough, respiratory infections, crepitations - LN rare **diagnosis:** - _biopsy_ - _CXR:_ diffuse reticulonodular pattern with hilar adenopathy, ground glass **PFTs**: restrictive **treatment:** steriods, hydroxychloroquinolone **prognosis:** high long term mortality

Answer 12

**prenatal:** reduced fetal O2 - placenta (reduced cap volume, spasm) - CO exposure - nicotine effect lung development - spontaneous loss **birth:** - LBW \<2500g, preterm, PPROM, placenta previa/abruption - decreased preeclampsia **postnatal:** - decreased milk supply - 1.4x neonatal death, SIDS RR 2-7 - asthma, OM, colic, short, behavioural issues, metabolic sx

Answer 13

**pathology:** iron in Fe3+ form and unable to bind oxygen **normal %**: 1-2% **causes of increased MetHb:** - _medications:_ NO, dapsone, nitrates, benzocaine, sulfonamides - _disease_: GIT infection, sepsis, SS crisis - _genetic:_ NADH MetHb reductase def, PKD, G6PD, HbM disease **clinical:** - oximetry reads 85% regardless of saturations - _3-15%_: grey/blue discolouration - _25-50%_: headache, dyspnoea, weakness, confusion - _50-70%_: arrythmia, altered GCS **treatment:** - _methylene blue_: 1^st line antidotal agent accelerates the enzymatic reduction of MetHb - hyperbaric oxygen - RBC exchange transfusions

Answer 14

**diagnosis:** FEV₁ out of proportion to decreasd FEV₁/FVC

Answer 15

**incubation:** 3 weeks **incidence:** 50% pneumonia in adolescence **clinical:** headache, malaise, low grade temp, resp sx, pharyngitis - _extrapulmonary:_ haemolysis, rash, CNS involvement (transverse myositis, PN), GI, polyarthritis **associations:** common in HIV **diagnosis:** - _serum_: haemolysis, neutrophilia, elevated titres (7-9 days) **CXR:** peribronchial pneumonia with areas of atelectasis and interstitial infiltration - pleural effusion 20%

Answer 16

**definition:** cause airflow limitation in expiration **diagnosis:** - increased RV/FRC(gas trapping) - decreased PEF - _FEV₁_correlates severity - _FEF _25-75:_ more accurate but less reliable (use in severe)

Answer 17

**incidence:** 27% children snore and 5% OSA, age 2-8 years **pathophysiology:** reduced cross sectional area of upper airway during inspiration - increased airway resistance/reduced pharyngeal dilators cause negative pressure and upper airway collapse **risk factors:** - tonsils: increase in size to age 12, smoking, rhinitis - other: obesity, family history, T21 **clinical:** - _night_: loud disruptive snoring with pauses/choking/arousals, restless sleep - _day:_ morning headache, dry mouth, nasal congestion, poor appetitie, FTT, secondary enuresis, behavioural issues **diagnosis**: polysomnogram - positive if hypopnoea index \>1/hour of sleep **treatment:** adenotonsillectomy, weight loss, CPAP

Answer 18

**incidence:** 5-10% all children with pneumonia **organisms:** S.pneumonia, S.aureus, mycoplasma (20%), viral (10%) **pathophysiology: collection of pus in the pleural cavity** - _3 stages_: exudative, fibrinopurulent, organization **clinical:** - as for pneumonia with dullness to percussion, fever, malaise, chest pain - consider in anyone febrile or unwell post IVAB **complications:** bronchopleural fistula, pyo-pneumothorax **CXR:** white out +/- mediastinal shift **US:** to confirm if loculated or simple **diagnosis:** fluid (MCS, exudate vs transudate) **treatment:** - small \<5 days: IVAB - large/distress/\>5 days: thoracocentesis or chest drain - persistent: VATS, chest tube

Answer 19

**Transudate** _cause:_ increased hydrostatic pressure, decreased colloid/osmotic pressure _appearance:_ clear _content:_ SG\<1.012, protein \<25g/L, cholesterol \<45mg/dL _fluid protein:serum protein_ \<0.5 _fluid albumin:serum albumin_ \>1.2g/L _fluid LDH_: \<0.6 **Exudate** _cause:_ inflammation _appearance:_ cloudy _content:_ SG\>1.020, protein \>29g/L, cholesterol \>45mg/dL _fluid protein:serum protein \>_0.5 _fluid albumin:serum albumin \<_1.2g/L _fluid LDH_: \>0.6

Answer 20

**clinical:** insidious onset fever (80-100%), cough, dyspnoea, crepitations, HSM - also weight loss, chills, fatigue **CXR:** diffuse alveolar infiltrates, pleural effusions

Answer 21

**apnoea:** \>90% decrease in airflow lasting \>90% duration of 2 normal breaths - _obstructive_: continuous inspiratory effort during apnoea - _central_: no effort with desats \>3%, assoc decreased HR **RERA** (respiratory effort related arousal): - duration of 2 breaths with increasing resp effort, flattening of insp portion of nasal pressure wave/snoring/high CO₂ leading to arousal **apnoea hypopnoea index (AHI):** no. apnoeas + hypopnoeas per hour **respiratory disturbance index (RDI)**: no. apnoeas/hypopnoeas/RERAS per hour **obstructive hypoventilation:** end tidal CO₂ exceeds 50_mmHg for \>25% of sleep **positive diagnosis:** apnoea-hypopnoea index\>1 and minimum sats\<92%

Answer 22

**incidence:** 1/10,000, M=F **definition:** congenital impairment of mucociliary clearance **pathophysiology:** defect in airway cilia causing immotility/aplasia - deletion dynein (commonest), absence radial spokes, abscent central tubule - defect in nodal cilia controlling normal position of heart/viscera **genetics:** AR, heterogenous, defective central cilia, flagella, matrix etc. **clinical:** cough/rhinitis/sinusitis +/- nasal polyps/agenesis frontal sinus - _pulmonary_: URTIs, chronic cough, wheeze, obstruction - _rhinosinusitis_: nasal congestion, polyposis - _otitis:_ defective ciliary function middle ear causing recurrent OM - _situs inversus_: 50% PCD - _fertility:_ males immotile sperm, women\<50% change pregnancy **diagnosis:** nasal nitric oxide, measure mucociliary clearance, nasal/bronchial brushings, EM (absence dynein arms) **monitoring:** PFTs, CXR, HRCT **management:** physio, mucolytics, AB, vaccinations, sinus surgery, lung transplant **prognosis:** slower decline than CF

Answer 23

**incidence:** most common LRT malformation **pathogenesis:** arise from anomalous budding of foregut during development at any part of the tracheobronchial tree **clinical: i**nfants with rapidly enlarging cysts may become symptomatic - more commonly present 2nd decade with coughing, wheeze, pneumonia **diagnosis:** - CXR: round water-density mass - CT: marginated cystic mediastinal mass with water attenuation **management:** surgical excision

Answer 24

**pathophysiology:** group of diseases with increased eosinophils in lungs/serum **causes:** - helminth/non-helminth infections - drugs: NSAIDs, ampicillin, sulfonamides - idiopathic acute/chronic eosinophilic pneumonia - Churg-Strauss (medium vasculitis): eosinophilic granulomatosis with polyangitis (sinusitis, asthma) - ABPA - hypereosinophilic sx **CXR:** ground glass opacities **treatment:** steroids

Answer 25

**pathogenesis:** failure of lobe or lung to develop **imaging:** mimics lobectomy **associations:** spinal abnormalities

Answer 26

Falsely **_high:_** carboxyhb, methb, sick cell Falsely **_low:_** hypoperfusion, anaemia, venous congestion **Left shift** (increased binding): - fetal Hb, low H⁺/CO₂/temp/2,3 BPG **Right shift** (decreased binding): - high H⁺/CO₂/temp/2,3 BPG

Answer 27

**pathophysiology:** abnormal development base of skull forming small foramen magnum that can compress cervicomedullary region causing apnoeas **clinical:** apnoea, cyanosis, feeding issues, quadriparesis, death

Answer 28

**disorders:** muscular dystrophy, congenital/metabolic myopathy, anterior horn cell disorders, PN, NMJ disorders **pathophysiology:** decreased muscle strength affects muscles of respiration reducing upper airway patency, cough and lung function - leading cause of morbidity/mortality in progressive NMD - inadequate ventilation may first manifest during sleep due to upper airway obs/reduced respiratory muscle function in sleep **diagnosis:** - PFTs: restrictive pattern with decresaed VC/FVC - polysomnography: gold standard **treatment:** BiPAP, oxygen contraindicated

Answer 29

**diagnosis:** - TLC\<80% - decreased VC - decrease RV in intrinsic, normal RV in chest wall pathology **causes:** intrinsic lung disease, chest wall pathology, NMD

Answer 30

**FEV1:** most reproducible **FEV25-75 (MMEFR):** most accurate for small airway obstruction but variability **PEFR:** monitor disease progression **Poor effort:** usually problem with sustaining adequate exp **Variation:** require 3 attempts within 5% of each other

Answer 31

**FEV1:** gold standard for diagnosis and monitoring **FEV₁/FVC**= \<80% **post bronchodilator:** FEV₁ increase 12% **bronchial challenge** (histamine, mannitol, exercise) **withhold:** - beta agonists: short 8hr, medium 24hr, long 48hr - theohylline 12-48hr - leukotriene 24hr - antihistamine 24-62hr - tea/coffee/cola 24hr **aim:** drop FEV1 20% (normal all subjects) but at smaller doses for asthmatics ie. 0.8 vs 20mg/ml

Answer 32

**clinical:** acute and rapid course **CXR:** - _early illness_: lobar changes with pleural effusions - _late illness:_ wides opacifications, large pleural effusions, displaced intrathoracic structures, abscesses, airleaks (highly specific)

Answer 33

1) laryngomalacia 2) subglottic stenosis 3) vocal cord palsy

Answer 34

**incidence:** 2nd most common cause neonatal stridor **pathophysiology:** - primary: congenital - secondary: intubation, silent GOR, diptheria, burns **clinical:** biphasic/inspiratory stridor **investigation:** laryngoscopy **management:** improves with age but surgery may be required

Answer 35

**TLCO or DLCO** (transfer or diffusing capacity) - the extent to which oxygen passes from alveoli into blood **Transfer resistance=**1/TLCO **Transfer coefficient (KCO)=**TLCO/VA (VA=alveolar vol) **KCO increased:** restrictive defects eg. NMD, obesity **KCO decreased:** parenchymal/pulmonary disease eg. ILD

Answer 36

**incidence:** 3rd most common cause neonatal stridor **pathophysiology** - unilateral: paralysed VC abducted - bilateral: paralysed in adduction causing obstruction **cause** - iatrogenic (cardiac/thyroid surg), idiopathic (viral, AI), neurologic/central (Arnold-Chiari, tumour, hydroceph), injury/compression recurrent laryngeal nerve, trauma (birth) **clinical** - _unilateral_: absent/weak cry, stridor, aspiration, coughing, choking - _bilateral_: biphasic stridor, normal cry, weak voice **diagnosis:** nasolaryngoscopy **prognosis:** resolved within 6-12 months **treatment** _unilateral_: speech tx, surgery if aspiration of poor voice quality _bilateral:_ surgery to open/lateralise VC for airway, tracheo in 50%

Answer 37

**tidal volume:** decrease by 1/2 **upper airway resistance:** increase by 2

Answer 38

**N1:** transition to light sleep (easily roused) **N2:** light sleep (k complexes and spindles) **N3:** deep sleep or slow wave sleep (hard to rouse, regular breathing) **REM:** decreased tone, rapid eye movement, partial paralysis, vivid dreams, irregular breathing

Answer 39

**2 stages** 1. deep sleep 2. REM sleep

Answer 40

**OSA:** 1-3% - _assoc:_ snoring \>50% night, mouth breathing, struggling to breath, parental concern - _outcome_: decrements memory/attention **snoring:** 10-13%

Answer 41

**HIGH exhaled NO:** eosinophilic inflammation - eg. asthma FeNO\>33ppb **LOW nasal nitric oxide:** - PCD/CF