Paeds: Resp Flashcards
Cystic Fibrosis
what is it
an autosomal recessive genetic condition affecting mucus glands
Cystic Fibrosis
what is it caused by
a genetic mutation of the cystic fibrosis transmembrane conductance regulatory gene
on Ch7
Cystic Fibrosis
what is the most common variant of the cystic fibrosis transmembrane conductance regulatory gene
the delta-F508 mutation: codes for cellular channels, particularly a type of chloride channel
Cystic Fibrosis
what causes a lack of lipase in the digestive tract
thick pancreatic and biliary secretions that cause a blockage of the ducts
Cystic Fibrosis
what causes the susceptibility to airway infections and bacterial colonisation
low volume thick airway secretions that reduce airway clearance
Cystic Fibrosis
what causes male infertility
congenital bilateral absence of the vas deferens
the sperm have no way of getting from the testes to the ejaculate
Cystic Fibrosis
what is the mode of inheritence
autosomal recessive
Cystic Fibrosis
both parents are healthy, one sibling has cystic fibrosis and a second child does not have the disease, what is the likelihood of the second child being a carrier?
2 in 3
Cystic Fibrosis
when is it screened
at birth with the newborn bloodspot test
Cystic Fibrosis
what is often the first sign
meconium ileus (not passing meconium within 24h)
Cystic Fibrosis
sx
- chronic cough
- thick sputum production
- recurrent resp tract infections
- steatorrhoea
- abdo pain and bloating
- salty kisses
- failure to thrive
Cystic Fibrosis
why does steatorrhoea occur
due to the lack of fat digesting lipase enzymes
Cystic Fibrosis
signs
- low weight or height
- nasal polyps
- finger clubbing
- crackle + wheezes on auscultation
- abdo distention
what are causes of clubbing in children
- hereditary clubbing
- cyanotic heart disease
- infective endocarditis
- cystic fibrosis
- TB
- IBD
- liver cirrhosis
Cystic Fibrosis
what are the 3 key methods for establishing a diagnosis
- newborn blood spot testing
- sweat test
- genetic testing for CFTR gene during pregnancy
Cystic Fibrosis
what is the gold standard for diagnosis
sweat test
Cystic Fibrosis
what happens during a sweat test
- pilocarpine applied to skin patch
- electrodes places on either side and current is passed between electrodes
- this causes skin to sweat
- sweat absorbed by filter paper
- sent to lab for Chloride conc
Cystic Fibrosis
what is the diagnostic concentration in the sweat test
> 60mmol/l
Cystic Fibrosis
why does bacteria colonate in these pts easily
they struggle to clear secretions in the airway
perfect environment with moisture and oxygen to colonise
Cystic Fibrosis
what are key microbial colonisers
Staph aureus
pseudomonas
Cystic Fibrosis
how do pts prevent staph aureus infection
take long term prophylactic flucloxacillin
Cystic Fibrosis
why should CF patients stay away from each other
risk of spreading pseudomonas
Cystic Fibrosis
why are pseudomonas difficult
resistant to multiple antibiotics
significant increase in morbidity and mortality
Cystic Fibrosis
trx for Pseudomonas colonisation
long term nebulised abx: tobramycin
PO ciprofloaxin alternatively
Cystic Fibrosis
mnx
- chest physio
- exercise
- high calorie diet
- CREON tablets
- prophylactic flucloxacillin
- treat chest infections
- salbutamol
- neb DNase (dornase alfa)
- neb hypertonic saline
- vaccinations: pneumococcal, influenza, varicella
Cystic Fibrosis
what is Nebulised DNase (dornase alfa)
an enzyme that can break down DNA material in respiratory secretions, making secretions less viscous and easier to clear
Cystic Fibrosis
why do they need follow up every 6m
- sputum culture for pseudomonas
- screening for diabetes, osteoporosis, vitamin D deficiency and liver failure
Bronchiolitis
what is it
inflammation and infection in the bronchioles, the small airways of the lungs
Bronchiolitis
what is it caused by
Respiratory syncytial virus (RSV)
Bronchiolitis
what age is it most common in
<6m
Bronchiolitis
what is heard on auscultation
wheeze and crackles
Bronchiolitis
why does it have a significant effect on infants and not adults
the airways of infants are very small to begin with
so even the smallest amount of inflammation and mucus in the airway has a significant effect on the infant’s abaility to circulate air to the alveoli and back out
Bronchiolitis
presentation
- Coryzal sx
- resp distress signs
- dyspnoea
- tachypnoea
- poor feeding
- mild fever
- apnoeas
- wheeze and crackles on auscultation
Bronchiolitis
what are coryzal sx
- snotty nose
- sneezing
- mucus in throat
- watery eyes
Bronchiolitis
signs of respiratory distress (9)
- raised RR
- use of accessory muscles
- intercostal recessions
- subcostal recessions
- nasal flaring
- head bobbing
- tracheal tugging
- cyanosis
- abnormal airway noises
Bronchiolitis
what is wheezing
whistling sound caused by narrowed airways, typically heard during expiration
what is grunting
caused by exhaling with the glottis partially closed to increase positive end-expiratory pressure
what is stridor
a high pitched inspiratory noise caused by obstruction of the upper airway, for example, in croup
Bronchiolitis
what is the typical RSV course
- starts with URTI: coryzal sx
- half get better, half develop chest sx over the next 1-2d
- sx last 7-10d
- fully recover in 2-3w
Bronchiolitis
what day are sx generally worst on
day 3-4
Bronchiolitis
what are infants more likely to have during childhood if they have had bronchiolitis as an infant
viral induced wheeze
Bronchiolitis
reasons for admission
- <3m
- preexisting condition: prem, Down’s, CF
- 50-75% less of their normal intake of milk
- clinical deyhdration
- RR>70
- O2 sats <92%
- mod-sev resp distress
- apnoeas
- parents not confident
Bronchiolitis
mnx
supportive:
- adequate intake,
- saline nasal drops and suctioning
- O2 if <92%
- ventilatory support if required
Bronchiolitis
mnx: why is it important to avoid overfeeding
a full stomach will restrict breathing
start with small frequent feeds and gradually increase as tolerated
Bronchiolitis
what are the steps in order of severity for ventilatory support
- high flow humidified O2
- CPAP
- intubation + ventilation
Bronchiolitis
what is high flow humidified O2
via tight nasal cannula
delivers air + O2 continuously with some added pressure
it adds positive end-expiratory pressure to maintain the airway at the end of expiration
Bronchiolitis
what is CPAP
sealed nasal cannular performs similarly to high flow (Airvo ot Optiflow)
but can deliver much higher and more controlled pressures
Bronchiolitis
what does intubation and ventilation involve
inserting an endotracheal tube into the trachea to fully control ventilation
Bronchiolitis
what inx is useful in severe resp distress and in monitoring children who are having ventilatory support
capillary blood gas
Bronchiolitis
what are the most helpful signs of poor ventilation
- rising pCo2
- falling pH
Bronchiolitis
what does rising pCO2 show
the airways have collapsed and can’t clear waste CO2
Bronchiolitis
what does a falling pH show
CO2 is building up and not able to buffer the acidosis this creates
this is resp acidosis
Bronchiolitis
which babies are high risk
ex-premature
congenital heart disease
Bronchiolitis
what is given to high risk babies
Palivizumab
Bronchiolitis
what is Palivizumab
a monoclonal antibody that targets RSV
monthly injection is given as prevention against RSV
Bronchiolitis
why is Palivizumab not a true vaccine
it does not stimualte the infant’s immune response
it provided passive protection
Viral-Induced Wheeze
what is it
an acute wheezy illness caused by a viral inection
Viral-Induced Wheeze
pathophysiology
virus
inflammation and oedema, swelling the walls of the airways
smooth muscle constricts
wheeze due to air flowing through these narrow airways
Viral-Induced Wheeze
what is Poiseuille’s law
flow rate is proportional to the radius of the tube to the power of 4
slight narrowing of an infant’s airway leads to a proportionally larger restriction in airflow.
Viral-Induced Wheeze
what are they more at risk of developing in later life
asthma
Viral-Induced Wheeze
what is the difference between asthma and viral induced wheeze
viral induced wheeze:
- presenting before 3y
- no atopic hx
- only occurs during viral infections
asthma:
- other triggers: cold, dust, emotions
- reversible airflow obstruction
Viral-Induced Wheeze
presentation
- initially viral illness
- SOB
- signs of resp distress
- expiratory wheeze throughout the chest
what could a focal wheeze show
focal airway obstruction such as an inhaled foreign body or tumour
Viral-Induced Wheeze
mnx
same as acute asthma in children
what is the most common side effect of salbutamol
tachycardia
Acute asthma
signs of moderate severity
- Peak flow > 50 % predicted
- Normal speech
Acute asthma
signs of severe severity
- Peak flow < 50% predicted
- Saturations < 92%
- Unable to complete sentences in one breath
- Signs of respiratory distress
- RR:
> 40 in 1-5 years
> 30 in > 5 years - HR
> 140 in 1-5 years
> 125 in > 5 years
Acute asthma
signs of life threatening severity
- Peak flow < 33% predicted
- Saturations < 92%
- Exhaustion and poor respiratory effort
- Hypotension
- Silent chest
- cyanosis
- altered consciousness/confusion
Acute asthma
stepwise approach in mnx
- salbutamol inhaler via spacer (10 puffs/2hr)
- nebulisers: salbutamol/ipratropium bromide
- PO prednisolone (1mg/kg OD for 3d)
- IV hydrocortisone
- IV magnesium sulphate
- IV salbutamol
- IV aminophylline
Acute asthma
why Consider monitoring the serum potassium when on high doses of salbutamol
salbutamol causes potassium to be absorbed from the blood into the cells.
Croup
what age does it affect
6m - 2y
Croup
what is it
URTI causing oedema in the larynx
Croup
classic cause
parainfluenza virus
also:
influenza
adenovirus
Croup
croup caused by diphtheria leads to what
epiglottitis
Croup
presentation
- ‘barking’ cough occurring in clusters
- low grade fever
- increased work of breathing
- hoarse voice
- stridor
Croup
conservative mnx
most cases can be managed at home:
- fluids + rest
- sit child up + comfort them
- hand wash
- stay off school
Croup
medical mnx
DEXAMETHASONE
single dose 150mcg/kg
repeated after 12h if required
Croup
medical mnx where dexamethasone trx is not available (in GP)
prednisolone
Croup
Stepwise options in severe croup
- PO dexamethasone
- Oxygen
- neb budesonide
- neb adrenaline
- intubation + ventilation
Whooping Cough
cause
Bordetella pertussis (a gram negative bacteria)
Whooping Cough
presentation
- starts with mild coryzal sx, low grade fever, dry cough
- 1w later, paroxysmal cough + coughing fits until out of breath
- loud inspiratory whoop when the coughing ends
- apnoea
Whooping Cough
patients can cough so hard they ___
faint, vomit or even develop a pneumothorax
Whooping Cough
inx to confirm dx
nasopharyngeal or nasal swab with PCR testing or bacterial culture
within 2-3w of onset of sx
Whooping Cough
inx if cough has been present >2w and aged 5-16y
anti-pertussis toxin immunoglobulin G
in the oral fluid
Whooping Cough
inx if cough has been present >2w and aged over 17y
anti-pertussis toxin immunoglobulin G
in the blood
Whooping Cough
is it notifiable
yes
Whooping Cough
mnx
supportive
Whooping Cough
mnx for vulnerable or acutely unwell patients, those <6m and patients with apnoeas, cyanosis or patients with severe coughing fits
- may need to admit
- ## azithromycin /erythromycin/clarithromycin within first 21d
Whooping Cough
which close contacts are given prophylactic abx
close contacts in a vulnerable group e.g. pregnant, unvaccinated infants, healthcare workers with close contact with children or pregnant women
Whooping Cough
prognosis
‘100 day cough’
sx typically resolve within 8w
Whooping Cough
key complication
bronchiectasis
Ddx for stridor
- croup
- epiglottitis
- foreign body
Epiglottitis
cause
haemophilus influenza type B
unvaccinated child presenting with a fever, sore throat, difficulty swallowing that is sitting forward and drooling
what is it
epiglottitis - a emergency
Epiglottitis
presentation
- sore throat
- stridor
- drooling
- tripod position (sat forward with hand on each knee)
- high fever
- difficulty or painful swallowing
- muffled voice
- scared + quiet child
- septic + unwell appearance
Epiglottitis
should you examine the throat
no
Epiglottitis
inx
lateral xray of the neck
Epiglottitis
what will the lateral xray of the neck show
thumb sign” or “thumbprint sign”.
soft tissue shadow that looks like a thumb pressed into the trachea
caused by the oedematous + swollen epiglottis
Epiglottitis
immediate mnx
- do not distress child
- alert most senior paediatrician + anaesthetist
- ensure airway is secure:
may need intubation or tracheostomy
Epiglottitis
additional trx once airway is secure
- IV ceftriaxone
- dexamethasone
Epiglottitis
common complication
epiglottic abscess
collection of pus around the epiglottis.
Epiglottitis
trx of an epiglottic abscess
similar to epiglottitis
Chronic Asthma
Children are usually not diagnosed with asthma until they are at least ___
2-3y
Chronic Asthma
inx where there is intermediate probability of asthma or diagnostic doubt
- spirometry w/ reversibility testing (>5y)
- direct bronchial challenge test w/ histamine or methacholine
- fractional exhaled NO (FeNO)
- peak flow diary
Chronic Asthma
medical therapy <5y
1) SABA
2) + low does ICS or LTRA (montelukast)
3) + other option from step 2
4) refer
Chronic Asthma
medical therapy aged 5-12y
1) SABA
2) + low does ICS
3) + LABA (salmeterol) only if good response
4) switch to medium dose ICS + consider adding PO LTRA, PO theophylline
5) switch to high dose ICS
6) refer. may need PO steroids
Chronic Asthma
medical therapy aged >12y (same as adults)
1) SABA
2) + low dose ICS
3) + LABA (salmeterol)
4) switch to medium dose ICS + consider trial of PO LTRA, theophylline or inh LAMA (tiotropium)
5) switch to high dose ICS + combine trx from step 4 + PO SABA. Refer
6) + PO steroids
Chronic Asthma
mum worried that ICS slows growth. What do you say?
- can cause a small reduction in final adult height of up to 1cm when using long term (>12m)
- ICS is used to prevent poorly controlled asthma and asthma attacks that could lead to higher doses of PO steroids
- poorly controlled asthma can lead to more significant impact on growth + development
- regular asthma reviews to ensure they are growing well and on the minimal dose required to effectively control symptoms.
Pneumonia
characteristic chest signs of pneumonia
- bronchial breath sounds
- focal coarse crackles
- dullness to percussion
Laryngomalacia
what is it
the larynx above the vocal cords (the supraglottic larynx) is structured in a way that allows it to cause partial airway obstruction.
‘floppy airway’
Laryngomalacia
what is stridor
a harsh whistling sound caused by air being forced through an obstruction of the upper airway
Laryngomalacia
what is the structural change
the aryepiglottic folds are shortened, which pulls on the epiglottis and changes it shape to a characteristic “omega” shape.
The tissue surrounding the supraglottic larynx is softer and has less tone in laryngomalacia, meaning it can flop across the airway
Laryngomalacia
at what age does it peak
6m
Laryngomalacia
presentation
- inspiratory stridor
- more prominent when feeding, upset, lying on back or URTI
- difficulties feeding
- not usually associated with resp distress
Laryngomalacia
mnx
no interventions are required and the child is left to grow out of the condition.
Rarely tracheostomy may be necessary
Chronic Lung Disease of Prematurity
what is it aka
bronchopulmonary dysplasia
Chronic Lung Disease of Prematurity
features
- resp distress syndrome
- low O2
- increased work of breathin g
- poor feeding + weight gain
- crackles + wheezes on chest auscultation
- increased susceptibility to infection
Chronic Lung Disease of Prematurity
prevention before birth
- corticosteroid to mother that show signs of premature labour at <36w gestation
Chronic Lung Disease of Prematurity
once the neonate is born, the risk can be reduced by?
- CPAP rather than intubation + ventilation when possible
- caffeine to stimulate resp effort
- not over- oxygenating
Chronic Lung Disease of Prematurity
how is dx made
- CXR changes
- require O2 after 36w gestational age
- sleep study to assess their oxygen saturations
Chronic Lung Disease of Prematurity
mnx
- may be discharged from the neonatal unit on a low dose of O2 to continue at home
- followed up to wean the oxygen level over the first year of life.
Chronic Lung Disease of Prematurity
what do babies with CLDP every month
palivizumab injections to protect against RSV to reduce risk of bronchiolitis
Primary Ciliary Dyskinesia
aka
Kartagner’s syndrome
Primary Ciliary Dyskinesia
what is it
an autosomal recessive condition affecting the cilia of various cells in the body
Primary Ciliary Dyskinesia
whom is it more common in
consanguinity
Primary Ciliary Dyskinesia
pathophysiology
- dysfunction of motile cilia
- build up mucus in lungs
- good site for infection
- similar to CF with frequent chest infections
Primary Ciliary Dyskinesia
where is there reduced fertility
It also affects the cilia in the fallopian tubes of women and the tails (flagella) of the sperm in men
Primary Ciliary Dyskinesia
what is Kartagner’s triad
3 key features of PCD:
- paranasal sinusitis
- bronchiectasis
- situs inversus
Primary Ciliary Dyskinesia
what is situs inversus
where all the internal (visceral) organs are mirrored inside the body
Primary Ciliary Dyskinesia
what is dextrocardia
when only the heart is reversed
Primary Ciliary Dyskinesia
which condition is it strongly associated with
situs inversus
Primary Ciliary Dyskinesia
diagnostic inx
- nasal brushing or bronchoscopy to obtain sample of ciliated epithelium of the upper airway
Primary Ciliary Dyskinesia
mnx
similar to CF + bronchiectasis:
- daily physio
- high calorie diet
- abx
