Respiratory Flashcards
(120 cards)
1
Q
Changes in airway diameter with inspiration/expiration
A
Upper airways narrow with inspiration, dilate with expiration
Lower airways dilate with inspiration, compressed by expiration
This is why stridor is heard in inspiration, and wheeze is heard in expiration
2
Q
which spirometry measure is most sensitive in kids with small airway disease
A
FEF 25-75
most sensitive marker of obstruction
(but is also very variable)
3
Q
what is the maximal allowable variation in flow volume loops on repeat testing
A
5%
4
Q
what measure best approximates height if this cannot be done (ie underlying disease)
A
arm span approximates standing height
5
Q
Simple spirometry rules
A
Low FEV1/FVC= obstruction present
Normal FVC= rules out restriction
Normal FEF 25-75= rules out obstruction
Positive bronchodilator response = increase by 12% in FEV1 and increase by 200ml from baseline
6
Q
A
7
Q
what parameter is used as a marker of lung function in obstructive disease
A
FEV1
Most useful long term measure of disease progression in obstructive lung disease
Used for monitoring of lung function in CF, corrolates well with severity of obstructive lung disease
8
Q
What parameter is used to monitor lung function in restrictive disease
A
FVC
max air blown out after full inspiration
- this is normal or reduced in obstructive disease due to gas trapping and hyperinflation
- always reduced in restrictive disease; degree of reduction linked with degree of impairment
but should do sleep study first
eg DMD
FVC <60%= REM sleep disordered breathing
FVC <40%= NREM + REM sleep disordered breathing
FVC <20%= daytime respiratory failure
9
Q
What are the hallmarks of restrictive disease
A
Characterised by reduced lung volumes or reduced lung compliance
Reduced total lung capacity (TLC) and FVC <80%
Reduced FEV1 (<80% of the predicted normal)
Reduced FVC (<80% of the predicted normal)
FEV1/FVC ratio normal or increased (>0.7)
Reduced FRC (due to reduced compliance)
10
Q
Hallmarks of obstructive lung disease
A
Reduced FEV1 (<80% of the predicted normal)
Reduced FVC (but to a lesser extent than FEV1)
FEV1/FVC ratio reduced (<0.7)
Reduced FEF max and FEF 25-75 (this is earliest change in small airway obstruction)
Increased TLC, VC, FRC and RV due to incomplete expiration/gas trapping
Reduced peak expiratory flow, inspiration relatively preserved
11
Q
When would you see an increased FRC?
A
FRC = functional residual capacity
Volume left in lungs after tidal expiration
Caused by intrathroacic obstruction ie incomplete exhalation
12
Q
Causes restrictive lung disase
A
Intrinsic lung disease = interstitial fibrosis
Chest wall pathology = eg. Scoliosis, abnormal chest wall
Neuromuscular disease = eg. DMD
CF (mixed)
Obesity
13
Q
Causes obstructive lung disease
A
o Asthma
o CF
o Bronchiolitis obliterans
Emphysema
14
Q
Narrowest part of paediatric airway
A
subglottis: from underside of true vocal cords to inferior margin of cricoid cartilage
15
Q
Upper airway obstruction (extrathoracic) - flow volume loop
A
Upper airway narrows in inspiration therefore Inspiratory curve reduced
Expiratory curve normal
eg. supraglottic leisons
laryngeal paralysis, unilateral vocal cord paralysis, laryngomalacia, croup/epiglottitis , laryngeal web
16
Q
Variable intrathoracic upper airway obstruction - flow volume loop
A
o During inspiration the intrathoracic obstruction expands due to negative pleural pressure normal curve
o During expiration pleural pressure positive relative to airway pressure flattened curve
Flow volume loop = normal inspiratory curve, flattened/truncated expiratory curve
eg tracheomalacia, bronchomalacia, vascular rings and webs, FB in bronchus
17
Q
what would you seen if there was fixed central or upper airway obstruction
A
Flow volume loop flattened in both inspiration and expiration (both limited equally)
As there cant be any increase in volume during expiration due to the fixed nature
**subglottis is the narrowest part of the trachea, so mild narrowing leads to huge increase in resistance.
Subglottic stenosis second most common cause of stridor (after laryngomalacia). Stridor is biphasis or primarily inspiratory. May have first symptoms with URTI as oedema and secretions narrow an already compramised airway. recurrent croup is common
eg tracheal stenosis, subglottic stenosis, bilateral VC paralysis, subglottic haemangioma, laryngea web, vascular ring
18
Q
Diffusion capacity (DLCO)
A
The DLCO measures the ability of the lungs to transfer gas from inhaled air to the red blood cells in pulmonary capillaries.
19
Q
Causes of false positive sweat test results
A
Adrenal insufficiency
Neohrogenic DI
Hypothyroidism
Hypoparathyroidism
Malnutrition
Metabolic syndromes -eg GSD
Atopic dermatits
Familial cholestasis syndrome
Pancreatitis
G6pd
20
Q
Causes false negative sweat test
A
Oedema
Inadequate stimulation/collection
Minerallocorticoid use
21
Q
Pathogenesis of bronchiolitis obliterates
A
Bronchiolitis obliterans (BO) is a rare, chronic lung disease of bronchioles and smaller airways.
It most commonly occurs in children after lung infection e.g. adenovirus, mycoplsma, measles, influenza, pertussis. Other causes include connective tissue disease, toxin fume inhalation, post lung or BM transplant. With adenovirus, it is types 7 and 21 which are the most concerning.
After the initial insult, inflammation leads to obliteration of the airway lumen causing air trapping or atelectasis. Bronchiolitis obliterans organising pneumonia (BOOP) is a fibrosing lung disease that includes histological features of BO with extension into alveoli with proliferation of fibroblasts
Clinical, there is initially cough, fever, cyanosis, and respiratory distress . Progression leads to increasing cough, SOB, wheezing, and sputum production.
CXR is relatively normal or demonstrates hyperlucency and patchy infiltrates. PFTs have variable findings, but typically an obstructive picture. VQ scan has a typical moth-eaten matched defects. CT shows patchy areas of hyperlucency and bronchiectasis
An open lung biopsy is required for definitive diagnosis. There is no definitive therapy, but corticosteroids may be beneficial. Immunomodulators are used in post-transplant patients.
Some patients rapidly deteriorate and die within weeks, and most non-transplant patients survive with chronic disability. 60-80% BOOP patientss survive but relapse can occur
22
Q
DLCO results in pulmunary vascular disease
A
In pulmonary hypertension, the DLCO is reduced. The VA is typically normal, and the KCO (DLCO/VA) is reduced due to impairment at the alveolar-capillary interface.
23
Q
DLCO results in interstitial lung disease
A
DLCO is decreased by diffuse alveolar capillary damage. The VA is low due to the loss of aerated alveoli. The KCO (DLCO/VA) is often reduced to a lesser extent than the DLCO
24
Q
DLCO results in pneumonoectomy
A
If no lung disease in the remaining lung:
VA is decreased due to discrete loss of alveolar units. Blood flow is diverted to the remaining lung and the KCO (DLCO/VA) is usually increased. As a result, the DLCO is slightly decreased.
25
DLCO results in bronchiectasis/bronchiolitis obliterans
DLCO low
Improved when corrected for reduced alveolar volume (KCO reduced to a lesser extent than DLCO)
26
DLCO increased in..
Pulmunary haemorrhage
L-->R cardiac shunts
Mild left heart failure (increase capillary blood volume)
Obesity
Asthma
High altitute
Polycythemia
27
EVALI
E cigarette or vaping associated lung injury
causes:
lipoid penumonia
eosinophilic pneumonia
hypersensitivity pneumonitis
diffuse alveolar haemorrhage
ARDS
granulomatous pneumonitis
organising pneumonia
spontaneous pneumothorax
28
MOA Ivacaftor in CF
Potentiatior
Used for Class 3 mutations (at least 1 allele) eg G551b
Holds defective CFTR open so chloride can flow through / potentiates the channel opening probability of CFTR at cell surface
**remember this mutation is a gating mutation, so CFTR gets to cell membrane but doesnt allow Cl thorugh
For kids > 12 months
29
MOA Lumacaftor in CF
***used in combination with ivacaftor= orkambi ***
Corrector
Used if patient is homozygous for dF508 allele
Facilitates the processing and trafficking of CFTR to increase CFTR at cell surface ie
Helps CFTR protein form correct shape, move to cell surface and stay there longer
Age 6-11
30
MOA Trikafta in CF
Elexacaftor/tezacaftor/ivacaftor + ivacaftor
Must have at least 1 dF508 allele
Elexacaftor helps protein form into correct shape to allow traffic to cell surface
Tezacaftor also improves processing and trafficking of CFTR proteins
Age >12 yrs
31
ABPA treatment
Prednisolone 6-12 weeks
Antifungals (itraconozone, voriconazone) for 4 weeks after stopping steroids
Anti IgE (omalizumab)
32
CF related diabetes
occurs in 2nd decade of life
affects 20% adults
due to impaired secretion of insulin secondary to destruction of islet cells (obstructive damage to pancreas due to thick secretions)
often presents as a decline in lung function and weight loss
OGTT best screening test, fasting hyperglycemia and elevated Hba1c comes much later
Microvascular complications less common than other types of diabetes but they do occur; macrovascular complications are rare
Rx: insulin
33
meconium ileus
10-20% of newborns with CF
Presents as GI obstruction - distension, emesesis, failure to pass mec in first 48 hours
Can present as mec peritonitis from intrauterine bowel rupture
rx; contrast enema + laparotomy
34
Distal intestinal obstruction syndrome
5-10% , usually >15 years
accumulation of fecal material in terminal portion of ileum and caecum --> bowel obstruction
presents as cramping abdo pain, distension and constipation
35
Risks of fat soluable vitamin deficiencies in CF
Vit A- night blindness
Vit E- neurological dysfunction (ataxia, weakness, hyporeflexia), haemolytic anemia
Vit K- bleeding
Vit D- reduced bone density
36
Exocrine pancreatic insufficiency in CF
>85% affected
present in 2/3 from birth
symptoms: steattorhooea, poor weight gain, vitamin deficiency, oedema, hypoproteinemia, electrolyte loss, anemia
also leads to oxolate renal stones
37
Liver problems in CF
Liver involvement common
Focal biliary cirrhosis in up to 70%
Obstruction to bile flow leads to increased toxic bile acids and hepatocyte injury
Presentation
Asymptomatic deranged LFTs
Neonatal cholestasis
Hepatic steatosis and steatohepatis
Focal biliary cirrhosis
Cholelirhiasis and cholecystutis
Microgallbladder
38
Fertility in CF
Delayed puberty on average 2 years
90 % of males have azoospermia due to failure of development of wolfian duct structures
Female fertility impaired due to malnutrition and thick cervical mucous but pregnancy well tolorated in those with good lung function
39
MOA pulmozyme
Colonisation if bacteria in airways —> accumulation of neutrophils
Death of neutrophils —> increased DNA in mucous leading to even further thickening
Pulmozyme is a recombinant DNAase that cleaves extracellular DNA released from dead neutrophils in sputum thus reducing viscosity
Improves pulmonary function and decreases exacerbations
40
Antibiotics for exacerbation of CF pseudomonas positive
Mild- oral ciprofloxacin
Severe- iv tobramycin + piptaz or ceftazadime
41
Symdeko in CF
Tezacaftor + ivacaftor
Approved for >12 years with homozygous delF508 or at least 1 residual function mutation
Tezacafor is a corrector, helps the defective protein form correct shape, traffic to cell surface and stay there longer
Fewer side effects than lumacaftor+ ivacaftor
If f508 positive, Trinkafta is the gold standard
42
Azithro in CF
Anti inflammatory action
3 times weekly from time of aquisition of pseudomonas
Don’t give if infected with no tuberculous mycobacteria
43
Pulmunary sequestration
is a congenital pulmonary malformation, comprised of a mass of non-functioning primitive tissue that does not communicate with the tracheobronchial tree.
44
Bacterial tracheotis presentation
Bacterial tracheitis is an uncommon infectious cause of acute upper airway obstruction. It is more prevalent than acute epiglottitis in children who have been vaccinated with Haemophilus influenza B. Bacterial tracheitis can be suspected in patients who present with croup-like symptoms (barking cough, stridor and fever) and preceding viral infection, but have a more toxic presentation and do not respond to standard croup therapy, because they have developed a secondary bacterial infection (e.g., Staphylococcus aureus, Moraxella catarrhalis or Haemophilus influenza). Acute airway obstruction can develop secondary to subglottic oedema and sloughing of the epithelial lining or accumulation of mucopurulent membrane within the trachea.
Bacterial tracheitis is differentiated from epiglottitis, because in the case of epiglottitis there would be a rapid prodrome, DROOLING, ABSENT COUGH, muffled voice, tripod positioning, and the chest X-ray would show pathology at the epiglottis.
Rx: nebulised adrenaline, oxygen, IV ceftriaxone
45
Discuss VQ mismatch in asthma
Worsening of hypoxaemia with administration of B2-agonists with air - hypoxia is not going to improve if V/Q mismatch is present.
Pattern of ventilation-perfusion is bimodal in acute severe asthma, ranging from normally perfused areas to areas of hypoxic pulmonary vasoconstriction.
Blood flow to the underventilated lung is decreased, thus maximising oxygenation by matching pulmonary perfusion to alveolar ventilation.
Administration of B2-agonists causes pulmonary vasodilation, thus increasing perfusion to underventilated lung units à worsening of VQ mismatch and increasing hypoxaemia
Salbutamol also increases cardiac output
Therefore, salbutamol should always be delivered with O2 in acute severe asthma, and O2 should be continued after the cessation of drug delivery
46
Discuss ABPA
. The diagnostic criteria for ABPA is:
Predisposing conditions (one must be present):
Cystic fibrosis
Asthma
Acute or subacute clinical deterioration (cough, wheeze, exercise intolerance, exercise-induced asthma, decline in pulmonary function, increased sputum) not attributable to another etiology.
PLUS
Obligatory criteria (both must be present):
Aspergillis skin test positivity or detectable IgE levels against Aspergillus fumigatus
Elevated total serum IgE concentration (typically>1000IU/mL, but if the patient meets all other criteria an IgE value <1000IU/mL may be acceptable)
Other criteria (at least two must be present):
Precipitating serum antibodies to Aspergillus fumigatus
Radiographic pulmonary opacities consistent with ABPA
Total eosinophil count >500cells/microL in glucocortoid-naïve patients
Chest CT is not essential to make the diagnosis because the chest X-ray has signs consistent with ABPA (parenchymal opacities and atelectasis due to mucoid impaction).
Sputum microscopy and culture will not give additional information to make the diagnosis.
47
Compliance calculation
Compliance = change in volume / change in pressure
48
Mantaux test interpretation
An induration of 5mm or more is considered positive in:
A recent contact with a person with tuberculosis disease
HIV infected people
People with fibrotic changes on chest X-ray consistent with prior tuberculosis
Patients with organ transplants
People who are immunosuppressed for other reasons
An induration of 10mm or more is considered positive in:
Recent immigrants (<5 years) from high prevalence countries
Children <4 years old
Infants, children and adolescents who are exposed to adults in high risk categories
People with clinical conditions that place them at high risk
An induration of 15mm or more is considered positive in:
Any person, including people with no known risk factors for tuberculosis
49
Psychogenic stridor
C: Paradoxical vocal cord motion (PVCM) refers to inappropriate movement of the vocal cords, which results in functional airway obstruction and inspiratory or expiratory stridorous breathing. PVCM is also called vocal cord dysfunction, Munchausen stridor, psychogenic stridor, factitious asthma, pseudoasthma, and irritable larynx syndrome. In the normal larynx, the true vocal cords abduct on inspiration, opening the glottis, and adduct partially during expiration, closing the glottic aperture about 10 to 40 percent. In PVCM, adduction of the true vocal cords occurs on inspiration, expiration, or both. PVCM has been associated with psychosocial disorders, stress, exercise, perioperative airway and neurologic injury, gastroesophageal reflux, and irritant inhalational exposures. Some patients have concomitant asthma or have been misdiagnosed with asthma. Most patients have normal expiratory spirometry.
Usually have normal lung function tests but difficulty with exercise with both stridor and wheeze
Exercise intolerance
50
Vital capacity
tidal volume + expiratory reserve volume + inspiratory reserve volume
51
inspiratory capacity
tidal volume + inspiratory reserve volume
52
total lung capacity
vital capacity + residual volume
53
functional residual capacity
residual volume + expiratory reserve volume
54
bronchogenic cyst
congenital malformation of bronchial tree- abnormal budding of foregut
do not usually communicate with bronchial tree- therefore usually fluid filled, with some proteinaceous material (not air filled)
most commonly located in the mediastinum, especially at the level of the carina.
Lined by respiratory epithelium + cartliage
In the proper clinical setting, a CT scan finding of a sharply marginated, non-enhancing, water-density mass is diagnostic of a bronchogenic cyst. (i.e. not air-filled).
usually asymptomatic unless infected of compressing adjacent structuures
typically present with cough, wheeze, penumonia or an incidental finding on CXR
55
CPAM
Result from abnormalities of branching morphogenesis of the lung. They are hamartomatous lesions that are comprised of cystic and adenomatous elements arising from tracheal, bronchial, bronchiolar, or alveolar tissue.
Large lesions can compromise alveolar growth and development by compressing adjacent normal tissue. CPAMs have connections with the tracheobronchial tree, although the connecting bronchi are usually not normal.
The arterial supply and venous drainage from the lesion are from the pulmonary circulation
Type 1 – macrocystic, single or several large cysts
Type 2 – microcystic, multiple small cysts
Type 3 – lesion is solid with bronchiole-like structures, poorest prognosis
Clinical features are: presenting in neonatal period with resp distress, recurrent RTI, pneumothorax. Smaller lesions present in mild childhood with recurrent RTI and acute chest pain. CXR shows a cystic mass.
56
pulmunary sequstration
nonfunctioning mass of lung tissue that lacks normal communication with the tracheobronchial tree, and that receives its arterial blood supply from the systemic circulation. Most sequestrations occur in the lower lobes; however, they can occur anywhere within the thorax. Physical findings in patients with sequestration include an area of dullness to percussion and decreased breath sounds over the lesion. Patients with respiratory distress require immediate surgical intervention. Those with recurrent infections can be operated on electively
57
vitamin D and the lungs
Vitamin D improved type 2 pneumocyte maturation and promotes surfactant synthesis
inihibits smmoth muscle proliferation
low vitamin D is associated with the development of asthma and low FEV1
58
which infection in CGD would cause osteomyelitis of ribs as well as pneumonia
Aspergillis
other infections in CGD: staph aureus, serratia, nocardia, burkholderia cepacia
59
airway abnormalities in kids with downs syndrome
Obstructive sleep apnoea is the most common airway abnormality reported with a prevalence of 50-97% in children with Down syndrome.
A: The prevalence of laryngomalacia in children with Down syndrome is 50%.
B: The prevalence of tracheomalacia in children with Down syndrome is 33%.
C: The prevalence of lingual tonsil in children with Down syndrome is 30%.
D: The prevalence of complete tracheal ring in children with Down syndrome is 17.5%.
60
lung development stages
Psuedoglandular period (6-16 weeks) - by the end of this period all the major lung elements, except for those required for gas exchange (e.g. alveoli) have appeared.
Canalicular period (16-26 weeks) - bronchial lumens enlarge and lung tissue becomes vascularised. Bronchioles and alveolar ducts develop from terminal bronchioles.
Terminal saccular period (26 weeks to birth) - specialised cells appear (type 1 and type II alveolar cells) and produces surfactant. Alveoli are seen from 32 weeks.
Alveolar period (birth to 3 years) - terminal saccules, alveolar ducts, and alveoli increase in number.
61
Abberant right subclavian artery
classified as an incomplete vascular ring. Most common of the aortic arch anomalies. Instead of being the first branch (with right common carotid as the brachiocephalic artery) it arises on its own as the fourth branch, after the left subclavian artery. It then hooks back to reach the right side. Most hook back behind the oesophagus
Usually asymptomatic, but if symptomatic would generally only cause dysphagia, as it passes behind the oesophagus
Usually no intervention
62
Difference between tracheomalacia and laryngomalacia
Tracheomalacia is the dynamic collapse of trachea during breathing (abnormally compliant trachea) Intrathoracic --> airway collapse during expiration
Laryngomalacia is collapse of supraglottic structures during inspiration (reduced laryngeal tone leading to supraglottic collapse during inspiration -->floppiness above the vocal cords)
Clinical features include: low pitched stridor, gradually increase in severity to become loudest 4-8 months then resolve by 12-18 months, more intense with URTI, crying, feeding.
Most dont need surgery.
Usually present at ~2 weeks of life, not from birth
high calorie expendature so need high intake or NGT top ups
treat reflux!- always need PPI
symptoms usually resolve with time as the child grows
if severe- supraglattoplasty
63
extrathoracic causes of upper airway obstruction
common acute: croup, epiglottitis, retropharyngeal abscess, diphtheria
chronic: laryngomalacia most common, also tracheomalacia, vocal cord paralysis, subglottic stenosis
64
intrathoracic causes of upper airway obstruction
Intrathoracic obstruction can be from the trachea within thoracic inlet and bronchi. Compression causes wheezing.
Causes of intrathoracic obstruction include:
vascular rings, webs, external compression by tumours, lymph nodes
65
positive histamine challenge
fall in FEV1 by >20% indicated bronchial hyperresponsiveness
66
habit/psychogenic cough
Considered in any child with a cough lasting weeks to months, that has been refractory to treatment, disappearing with sleep or distraction. Typically the cough is abrupt and loud, with a harsh barking/honking quality. Dissociation between the child’s affect and the severity of the cough is typically striking. Speech path can be used to decrease tension in the neck muscles and raise awareness of initial sensations triggering cough.
67
Old vs new BPD
The lungs of infants with new BPD are characterised by minimal alveolarisation, less airway epithelial disease, less severe vascular disease, and less interstitial fibrosis compared with lungs with alternating zones of overdistention and atelectasis in infants with severe BPD. Thus, the new BPD is understood to reflect extreme lung immaturity with an arrest of alveolar growth and development and an inflammatory response to treatment induced injury that leads to cycles of lung injury and repair.
Normal alveolar multiplication is thought to be complete by 2–4 years of age.40 It is therefore unlikely that infants with chronic lung disease with alveolar hypoplasia in the first and second year of life will increase their alveolar numbers to normal values. Studies in an animal model showed that chronic lung disease results in a significant and permanent loss of alveoli.36 Infants of very low birth weight with an earlier interruption of lung development might be expected to end up with a greater degree of alveolar hypoplasia than those who are injured later in gestation; these very immature babies could therefore have even more severe lung dysfunction in adolescence and adulthood than those infants who acquired classic BPD
68
causes stridor
laryngomalacia - insp
unilateral VC palsy- insp
bilateral VC palsy or subglottic stenosis - biphasic, both insp and exp
subglottic haemagioma- insp
croup- insp
tracheomalacia- insp or exp depending if intrathoracic or extrathoracic
obstruction around larynx/trachea (middle airway)
69
causes wheeze
FB
tracheomalacia
vascular ring
asthma
obstruction small airways
70
stertor
narrowing upper airways- nose, adenoids, pharynx
71
symptoms laryngeal web
failure of recanulisation of larynx
usually at level of glottis (vocal cords)
associated with DiGeorge if congenital
can also be due to intubation
respiratory distress
weak or high pitched cry
later--> horse or weak voice
72
congenital subglottic stenosis
around level of cricoid
biphasic stridor if severe
most commonly presents as recurrent croup
usually improves with time as larynx grows
may be due to a subglottic haemangioma- not present at birth, rapid growth over first few weeks or months of life then involutes (so symptoms only present at few weeks of age with stridor and respiratory distress. "croup like presentation" but too early for croup)
look for other haemangiomas!
Rx: propranolol
biphasic stridor
horse voice
cough
73
bilateral vocal cord palsy
vocal cords dont abduct (ie dont open)
present at birth with respiratory distress or stridor (biphasic) and normal cry
most need tracheostomy
cause: idiopathic, birth trauma, perinatal asphyxia, hydrocephalus, chiari malformation, mediastinal tumor, prolonged intubation
74
unilateral vocalv cord palsy
weak cry
dysphasia/ feeding difficulties
mild resp distress
no stridor
cause: idiopathic, birth trauma, post surgery, compression y mediastinal massess
75
typical presentation of choanal atresia
unilateral- presents later in life with nasal discharge
bilateral- presents in neonatal perid with noisy breahtin, cyanosis, worsens during feeds, imprived with crying (mouth breathing)
Ix: failure to pass NGT
lack of fogging
nasal endoscopy
CT face
Rx: oral airway
McGovern nipple
OGT feeds
nasal stent
76
thyroglossal cyst
remenant of thyroglossal duct
midline neck lump
moves upward with tongue movement
can become infected and drain
can obstuct breathing or swollowing when enlarged
77
Pierre Robin Sequence
micrognathia
glossoptosis
upper airway obstruction
+/- cleft palate
obstruction of oropharynx worse when supine
Rx: nasopharyngeal tube to ensure airway patency
**associated with Stickler syndrome
**other major syndrome associated with micrognathia is Treacher Collins syndrome
78
differentiating retrophryngeal and peritonsillar abscess
retropharyngeal abscess
- usually occurs in kids <4 years
- fever, irritability, reduced PO intake, drooling
- neck stiffness, torticolus, refusal to move neck, or keeping neck hyperextended
- complaints of sore throat or neck pain
- muffled voice, stridor
peritonsillar abscess
- much more common than retropharyngeal abscess
- usually in later childhood/adolescence
- usually a complication of pharyngitis/tonsillitis
- neck swelling, sore throat, fever, TRISMUS, dysphagia, drooling, muffled voice
- asymetrical tonsillar bulge with displacement of uvula
- most commonly caused by GAS-
79
when is stridor most prominant in laryngomalacia
4-8 months
worse when supine, when crying or agitated, or with URTI
80
epiglottitis
usually caused by haemophilus influenzae B
peak incidence age 3
- abrupt onset high fever, agitation, stridor, dyspnoea, muffled voice, dysphagia, drooling
may prefer to sit forward with mouth open
NO COUGH
81
bacterial tracheitis
usually caused by staph aureus
less commonly by h. influenxae or moraxella catterhalis
usually presents in kids <3 years
usually follows URTI
presents with high fever, toxcity, COUGH and respiratory distress
82
Leukotrines
Produced by macrophages, neutrophils, eosinophils, and mast cells
The production of leukotrienes is usually accompanied by the production of histamine and prostaglandins, which also act as inflammatory mediators.
Leukotrines trigger contractions in the smooth muscles lining the bronchioles; their overproduction is a major cause of inflammation in asthma and allergic rhinitis.
Leukotriene antagonists are used to treat these disorders by inhibiting the production or activity of leukotrienes
83
Monteleukast
Leukotrine receptor antagonist
Used to prevent exercise induced bronchoconstriction, and to treat seasonal allergic rhinitis.
can have neuropsychiatric side effects/nightmares
oral tablet (not inhaled)
can be used as preventor as second step of pyramid (after PRN SABA)
84
steeple sign on CXR is seen in...
croup
--> subglottic tracheal narrowing
85
aberrant innominate (brachiocephalic)artery
most common cause of secondary tracheomalacia
usualy asymptomatic and discovered incidentally
may have stridor, cough, cyanotic spells (when food bolus compresses posterior wall of trachea)
86
dupilamab
used in asthma
blocks Il-4 and il-13 signallign
87
mepolizumab
severe eosinophilic asthma
anti-IL-5
reduced activation and proliferation of eosiniophils and B cells
88
omalizumab
severe asthma
anti -IgE
89
in which condition is exhaled nitric oxide markedly reduced
primary ciliary dyskineasia
CF
smokers
90
MoA Symdeko (Tezacaftor + ivakaftor)
homozygous delF508 OR at least one residual function mutation similar MOA to lumacaftor (corrector, helps to form right shape and traffic to membrane)
91
inspiratory reserve capacity
volume of air that can be inhaled above the tidal volume
92
Dead space
Physiological dead space= anatomic dead space + alveolar dead space
Anatomical dead space= total volume in the conducting airways from nose to the terminal bronchioles
Alveolar dead space= volume in alveoli that are ventilated but not perfused so gas exchange doesn’t occur
93
CF related diabetes
2 hr OGTT >11.1
Fasting glucose >7
HbA1C >6.5%
2 abnormal tests needed to confirm in the absence of polyuria or polydypsia
main defect is lack of insulin (due to exocrine pancreatic dysfunction)
Rx: insulin, high calorie diet
94
treatment of bronhciolitis obliterans
corticosteroids
95
lung function tests in bronchiolitis obliterans
initial obstructive pattern (concentric luminal narrowing)
then restrictive pattern (fibrosis)
96
differentiating types of restrictive lung disease with DLCO
DLCO normal in neuromuscular disease
DLCO reduced in interstitial lung disease
97
what does mepolizumab block
IL-5
98
herpangina
papulovesicular ulcerations (white) in the posterior oropharynx (soft palate, tonsillar pillars, pharyngeal wall)
severe throat pain
fever
cause: coxsackie A16 virus (+ other enteroviruses)
when lesions are on hands and feet also = hand foot and mouth disease
exclude from school until blisters on hands and feet have dried up
99
Lemierre syndrome
F. necrophorum pharyngitis
internal jugular vein septic thrombophlebitis
fever, exutative pharyngitis, neck pain and swelling --> toxicity
100
Diptheria
bull neck
grey pharyngeal pseudomembrane
can cause respiratory obstruction
Rx: IV penicillin
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under what age is GAS pharyngitis uncommon
<3 years
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HSV1 stomatitis
Usually between 1 -3 years
Manifests in multiple discrete lesions on the anterior palate (tongue, gums and hard palate) and vesicles on or around the lips. There is usually significant fever and lymphadenopathy. The main issue is pain causing poor feeding. The lesions usually resolve after five-seven days, but they are often triggered again in the future by other viral illnesses or stress.
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Antibiotics for CAP
Very mild, no admission: amoxicillin
Mild, needs admission, tolerating PO intake : amocixillin
Mild- mod, vomiting, reduced PO intake: benpen
Severe: cefotaxime/ceftriaxone +/- flucloxacillin
+ vancomycin if MRSA suspected
+ azithromycin if not improving
Oseltamivir for influenza
Empyema: benpen + lincomycin
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acquired trachemalacia caused by
vasular rings
correction of tracheooesophageal fistula
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congenital anomalies causing stridor
laryngomalacia
congenital subglottic stenosis
bilateral vocal cord paralysis (unilateral causes aspiration, coughing, weak and breathy cry)
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primary ciliary dyskineasia triad
chronic sinusistis
bronchiectasis
chronic otitis media
infertility (males more affected than females)
**absence of dyenin arms**
+ situs invertus = Kartagenrs syndrome (occurs in 50% of kids with PCD) (triad of situs invertus, chronic sinusitis, bronchiectasis)
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what stain is used to detect PJP
Methenamine silver nitrate is used to stain for fungi
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PJP
Clinically - CXR shows widespread pulmonary infiltrates. Another clinical finding is that arterial oxygenation is often strikingly lower than would be expected from symptoms.
PCP is identified by staining of cysts with methenamine silver nitrate, or toluidine blue, which stains dark bodies within the cysts.
Pneumocystis pneumonia is a well-recognised major opportunistic infection in HIV-positive individuals. Similar to other opportunistic fungal infections, Pneumocystis pneumonia is most often observed when the CD4+ T helper cell count falls below 200 cells/mm3. CD4+ T cells are absolutely critical for resolution of Pneumocystis, having an essential role in the recruitment and activation of effector cells against the organism.
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cause of impaired gas exchange in meconium aspiration syndrome
Aspiration induces hypoxia via four major pulmonary effects: airway obstruction, surfactant dysfunction, chemical pneumonitis, and pulmonary hypertension.
Airway obstruction
Complete obstruction of the airways by meconium results in atelectasis. Partial obstruction causes air trapping and hyperdistention of the alveoli, commonly termed the ball-valve effect. Hyperdistention of the alveoli occurs from airway expansion during inhalation and airway collapse around inspissated meconium in the airway, causing increased resistance during exhalation. The gas that is trapped (hyperinflating the lung) may rupture, causing an air leak (e.g. pneumothorax).
Surfactant dysfunction
Meconium deactivates surfactant and may also inhibit surfactant synthesis. Several constituents of meconium, especially the free fatty acids (e.g., palmitic, stearic, oleic), have a higher minimal surface tension than surfactant and strip it from the alveolar surface, resulting in diffuse atelectasis.
Chemical pneumonitis
Enzymes, bile salts, and fats in meconium irritate the airways and parenchyma, causing a release of cytokines (including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, I-L6, IL-8, IL-13) and resulting in a diffuse pneumonitis that may begin within a few hours of aspiration.
Direct injury and inflammation result in an exudative and inflammatory pneumonitis with epithelial disruption, proteinaceous exudation with alveolar collapse, and cellular necrosis.
In animal studies, pancreatic phospholipase A2 appears to directly contribute to lung injury.
All of these pulmonary effects can produce gross ventilation-perfusion (V/Q) mismatch.
Persistent pulmonary hypertension of the newborn
To complicate matters further, many infants with meconium aspiration syndrome (MAS) have primary or secondary persistent pulmonary hypertension of the newborn (PPHN) as a result of chronic in utero stress and thickening of the pulmonary vessels. PPHN further contributes to the hypoxemia caused by meconium aspiration syndrome.
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Emergency management of airway obstruction
O2
consider nebulised adrenaline, dexamethosone
emergency intubation
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preferred test for TB in child <5
tuberculin skin tests
IGRA not recommended <5 years
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what part of the lungs has the highest ventilation/perfusion ratio in the erect position
upper areas
V/Q ratios favour ventilation in
the non-dependent portions and perfusion in the dependent portions.
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what must you do before starting TB treatment
obtain culture for sensitivities!
either sputum or gastric sample
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Initial management of diaphragmatic hernia
In the delivery room, if the infant is known or suspected to have congenital diaphragmatic hernia, immediately place a vented orogastric tube and connect it to continuous suction to prevent bowel distension and further lung compression. For the same reason, avoid mask ventilation and immediately intubate the trachea.
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HUS as complication of pneumonia
HUS= hemolytic anemia, AKI (uremia) and thrombocytopenia
Strep pneumoniae associated HUS is 5% of all HUS
bacteria produce NEURAMINIDASE which damages endothelial cells
Blood smear= schistocytes (fragmented RBC) + giant platelets
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Paradoxical vocal cord motion (PVCM)/psychogenic asthma
refers to inappropriate movement of the vocal cords, which results in functional airway obstruction and inspiratory or expiratory stridorous breathing.
In the normal larynx, the true vocal cords abduct on inspiration, opening the glottis, and adduct partially during expiration, closing the glottic aperture about 10 to 40 percent. In PVCM, adduction of the true vocal cords occurs on inspiration, expiration, or both. PVCM has been associated with psychosocial disorders, stress, exercise, perioperative airway and neurologic injury, gastroesophageal reflux, and irritant inhalational exposures. Some patients have concomitant asthma or have been misdiagnosed with asthma. Most patients have normal expiratory spirometry.
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Polysomnography
PSG consists of a simultaneous recording of multiple physiologic parameters related to sleep and wakefulness. PSG can directly monitor and quantify the number of respiratory events (i.e. obstructive, central, or complex) and the resultant hypoxemia and arousals related to the respiratory events or even independent of the respiratory events.
Assessment of sleep stages requires 3 studies: electroencephalography (EEG), electrooculography (EOG), and surface electromyography (EMG).
The EEG channel is used to monitor sleep stage. Additional EEG channels can be used, particularly in patients with epilepsy (i.e. a full 10-20 montage). EOG channels are used to monitor both horizontal and vertical eye movements. Electrodes are placed at the right and left outer canthi, one above and one below the horizontal eye axis. Evaluation of the eye movements is necessary for 2 reasons. First is for documentation of the onset of rapid eye movement (REM) sleep, and second is to note the presence of slow-rolling eye movements that usually accompany the onset of sleep. The EMG channel (usually chin or mentalis and/or submentalis) is used to record atonia during REM sleep or lack of atonia in patients with REM-related parasomnias. To assess bruxism, the EMG electrodes can be placed over the masseter.
Other parameters that can be monitored in a sleep study include the following:
Airflow (nasal and/or oral)
Electrocardiography
Pulse oximetry
Respiratory effort (thoracic and abdominal)
Sound recordings to measure snoring
Continuous video monitoring of body positions
Stages of sleep, any abnormalities noted with EEG, and periodic limb movements are reported. Respiratory activity (eg, apneic or hypopneic episodes, oxygen desaturations) is correlated with sleep stages. Other parameters, such as body position, are recorded. Total time and relative proportion of the night spent in each of the stages and in REM and non-REM sleep are calculated. Latencies to REM and slow-wave sleep are reported.
Basic rules of polysomnography
All respiratory events counted are at least 10 seconds in duration
All events need to have at least a 3% or greater oxygen saturation (SaO2) decrease
EEG arousals occur with most respiratory events
Obstructive apnea
No airflow for greater than 10 seconds
Increasing respiratory effort; usually seen as paradoxical
SaO2 decrease greater than 3% (may be adjusted)
(Note – SaO2 does not need to decrease for the diagnosis of OSA to be made)
Hypopnea
Reduction in airflow to approximately 50% of baseline value
SaO2 decrease of greater than 3%
Usually is a steadily increasing effort signal and usually is associated with arousal
Mixed apnea
Complete absence of nasal and oral airflow
Total absence of respiratory effort at the beginning of the event, followed by a gradual increase in effort, which eventually breaks the apnea (usually paradoxical)
SaO2 decrease of greater than 3%
Central apnea
Absence of airflow at nose and mouth for greater than 10 seconds
Complete absence of respiratory effort
SaO2 decrease of greater than 3%
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specific lung compliance is best standardised by measuring lung compliance at which of the following lung volumes
FRC
(end of passive expiration - RV + ERV)
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Congenital lobar emphysema
characterised by hyperinflation of one or more of the pulmonary lobes. The most frequently identified cause of CLE is obstruction of the developing airway. CLE is characterised by overdistention of one or more lobes of the lung. This leads to compression of the remaining lung tissue and herniation of the affected lobe across the anterior mediastinum into the opposite chest, causing displacement of the mediastinum. Therefore any collapse would be in the contralateral lung. The left upper lobe is affected most often. The RLL is only affected in <10% of cases. Affected infants usually are symptomatic in the neonatal period.
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CPAM
They are hamartomatous lesions that are comprised of cystic and adenomatous elements arising from tracheal, bronchial, bronchiolar, or alveolar tissue. Large lesions can compromise alveolar growth and development by compressing adjacent normal tissue. CPAMs have connections with the tracheobronchial tree, although the connecting bronchi are usually not normal. The arterial supply and venous drainage from the lesion are from the pulmonary circulation,
