Respiratory Flashcards
Croup epidemiology and features
Croup is a form of upper respiratory tract infection seen in infants and toddlers. It is characterised by stridor which is caused by a combination of laryngeal oedema and secretions. Parainfluenza viruses account for the majority of cases.
Epidemiology
- peak incidence at 6 months - 3 years
- more common in autumn
Features
- stridor
- barking cough (worse at night)
- fever
- coryzal symptoms
Croup classification and reasons for admission
Admit with moderate/severe croup and other admission factors:
- <6 months of age
- known UA abnormalities (e.g. laryngomalacia, Down’s syndrome)
- uncertainty about diagnosis (e.g. epiglottitis, bacterial tracheitis, peritonsillar abscess and foreign body inhalation)
- pallor, cyanosis, decreased consciousness, RR>70, fatigue, asyncrhonous chest well and abdominal movement, sternal/intercostal recession
- increasing UA obstruction
- *Mild croup**: barking cough
- *Moderate**: + stridor/sternal recession at rest
- *Severe:** + agitation/lethargy, sternal/intercostal recession
Westley croup severity score (in image)
Croup Ix
clinical Dx
if CXR done:
- PA view = subglottic narrowing aka ‘steeple sign’
- Lateral view = swelling of epiglottis aka ‘thumb sign’
ix:
- Basic obs
- Examination
- Urine catch (hard to get)
- CXR = not usually done, steeple sign
tripod stance
NEVER examine a child’s throat (unsettles child)
Croup Mx
All severities croup:
- Oral dexamethasone (0.15 mg/kg)
- if not possible = inhaled beclomethasone (2mg) or IM dexamethasone (0.6/kg)
- can give while transported to hospital for admission
- incorporate paediatrician, nurses, anaesthetist → airway support STAT,
- provide analgesics
Hospital
- A to E, reduce temperature, start steroids, supportive care (fluids)
- then talk about community care
Mild croup:
- admission NOT required
- Advise to take child to hospital if continuous stridor heard or skin between ribs pulling in with every breath
- call ambulance if = pale/blue/grey for more than few seconds, unusually sleep or not responding, having a lot of trouble breathing, upset (agitated/restless) while struggling to breathe and cannot be calmed down quickly, unable to talk/drooling/trouble swallowing
Moderate croup:
- oxygen
Severe croup:
- oxygen (high flow via non-rebreathe mask)
- nebuliser adrenaline (1 in 1000 (1mg/ml)) = RISK OF REBOUND 2h later so needs close monitoring, observe on day unit until respiratory distress settles
Causes of stridor in children
What is laryngomalacia? features and ix, complications
Congenital abnormality of the larynx cartilage which predisposes to dynamic supraglottic collapse during inspiration of respiration → results in upper airway obstruction and stridor.
Most frequent congenital stridor in infants and cause ‘noisy breathing’ in infancy.
- 2-6 weeks old with noisy respiration and inspiratory stridor – worse supine, when feeding or if agitated
- ± association with GORD
- ± feeding difficulties, slow, ↑ cough/choking, ↑ respiratory noise
- Normal cry → no abnormality with vocal cords
- Not present at birth
- Baby is otherwise comfortable despite thenoise
Ix:
- monitor sats + laryngoscopy if diagnostic difficulty to assess anatomy and comorbidities
Complications = respiratory distress, failure to thrive, cyanosis
Laryngomalacia mx
- Manage conservatively with close observation
- Regular review and monitoring of growth
- Tend to resolve by 18-24 months (although
- may initially worsen with age, max at 6-8 months) – 70% resolve by 1 year old
Endoscopic supraglottoplasty if airway compromise or feeding disrupted sufficiently to prevent normal growth.
Asthma medical management for children aged 5 to 16
What is bronchiolitis, causes and epidemiology, more serious with…
Bronchiolitis is a condition characterised by acute bronchiolar inflammation. Respiratory syncytial virus (RSV) is the pathogen in 75-80% of cases.
OTHER CAUSES = mycoplasma, adenoviruses, 2o to bacterial infection
More serious if bronchopulmonary dysplasia (e.g. premature), congenital heart disease or CF
Epidemiology
- most common cause of a serious lower respiratory tract infection in < 1yr olds (90% are 1-9 months, with a peak incidence of 3-6 months). Maternal IgG provides protection to newborns against RSV
- higher incidence in winter
Features of bronchiolitis
coryzal symptoms (including mild fever) precede:
- dry cough
- increasing breathlessness
- wheezing, fine inspiratory crackles (not always present)
- feeding difficulties associated with increasing dyspnoea are often the reason for hospital admission
Bronchiolitis: when to make immediate referral and consider referring to hospital
‘consider’ referring to hospital if any of the following apply:
- a respiratory rate of over 60 breaths/minute
- difficulty with breastfeeding or inadequate oral fluid intake (50-75% of usual volume ‘taking account of risk factors and using clinical judgement’)
- clinical dehydration.
immediate referral (usually by 999 ambulance) if they have any of the following:
- apnoea (observed or reported)
- child looks seriously unwell to a healthcare professional
- severe respiratory distress, for example grunting, marked chest recession, or a respiratory rate of over 70 breaths/minute
- central cyanosis
- persistent oxygen saturation of less than 92% when breathing air.
How do we investigate bronchiolitis
clinical
immunofluorescence of nasopharyngeal secretions may show RSV
Bronchiolitis management and prevention
Infection control measures are required in the ward the patient is placed as RSV is highly infectious
Palivizumab (monoclonal antibody against RSV) reduces the number of hospital admissions in high-risk preterm infants
Nephrotic
Bronchiolitis vs Viral Episodic Wheeze
Bronchiolitis = crackles
VEW = wheeze
2 types of pre-school wheeze in children
- episodic viral wheeze: only wheezes when has a viral upper respiratory tract infection (URTI) and is symptom free inbetween episodes (not associated with asthma in later life)
- multiple trigger wheeze: as well as viral URTIs, other factors appear to trigger the wheeze such as exercise, allergens and cigarette smoke (a lot fo children with this end up with asthma)
Management of pre-school wheeze in children
Parents who are smokers should be strongly encouraged to stop.
Episodic viral wheeze
- treatment is symptomatic only
- first-line is treatment with short acting beta 2 agonists (e.g. salbutamol) or anticholinergic via a spacer
- next step is intermittent leukotriene receptor antagonist (montelukast), intermittent inhaled corticosteroids, or both
- there is now thought to be little role for oral prednisolone in children who do not require hospital treatment
Multiple trigger wheeze
- trial of either inhaled corticosteroids or a leukotriene receptor antagonist (montelukast), typically for 4-8 weeks
How do we diagnose Cystic Fibrosis?
On day 5 of life, newborns have the heel prick test. They are tested for cystic fibrosis (CF), congenital hypothyroidism, sickle cell disease, and a number of other metabolic diseases. For CF, the levels of IRT (immune reactive trypsinogen) are tested, and if they are raised that can indicate CF. The baby should then undergo the sweat test, and if this is raised, this confirms a diagnosis of CF.
Sweat test
- patient’s with CF have abnormally high sweat chloride
- normal value < 40 mEq/l, CF indicated by > 60 mEq/l
Causes of a false positive sweat test (and also false negative)
Causes of false positive sweat test
- malnutrition
- adrenal insufficiency
- glycogen storage diseases
- nephrogenic diabetes insipidus
- hypothyroidism, hypoparathyroidism
- G6PD
- ectodermal dysplasia
The most common reason for false negative tests is skin oedema, often due to hypoalbuminaemia/ hypoproteinaemia secondary to pancreatic exocrine insufficiency.
What causes whooping cough? (pertussis) when infants vaccinated?
G-ve Bordetella pertussis
Imms at 2,3,4 months and 3-5 years (infection/imms does not result in lifelong protection)
Features of whooping cough (pertussis)
Diagnosis criteria:
Acute cough >14 days w/o another apparent cause, and one or more of the following:
- paroxysmal cough (CATARRHAL PHASE)
- inspiratory whoop
- post-tussive vomiting
- undiagnosed apnoea attacks in young infants
2-3 days coryza precede onset of:
- coughing bouts = worse at night/after feeding, ended by vomiting, associated central cyanosis
- inspiratory whoop = forced inspiration against closed glottis
- apnoea spells
- persistent coughing → subconjunctival haemorrhages or anoxia → syncope/seizures
- sx’s 10 - 14 weeks and more severe in infants (→ CONVALESCENT PHASE)
- marked lymphocytosis
Whooping cough diagnostic ix
Per nasal swab culture for Bordetella pertussis = takes several days/weeks to come back
PCR + serology increasingly used as more available
Complications of pertussis
subconjunctival haemorrhage
pneumonia
bronchiectasis
seizures
Management of whooping cough
Notify HPU
Admit if:
- <6m or acutely unwell
- significant breathing difficulties (apnoea, severe paroxysms, cyanosis)
- complications (seizures, pneumonia)
Pharm = if NOT admitted, onset within 21 days (as does not shorten course but affects infectivity)
- <1m = clarithromycin
- >1m and not pregnant = azithromycin
- if pregnant = erythromycin (from 36 wk GA w/o vaccination to reduce risk of transmission to newborn)
- if macrolides CI → co-trimoxazole (do NOT use in pregnant/infants <6wks of age)
Advice:
- rest, adequate fluid intake, paracetamol/ibuprofen for sx relief
- inform parents, despite abx tx, disease likely to cause protracted non-infectious cough that may take weeks to resolve
- children avoid nursery until 48 hours of abx tx has been completed, or until 21 days after onset of cough if not treated with abx
- once acute illness dealt with, advise parents to complete any outstanding imms
Assessment of acute asthma attacks
Management of life-threatening/severe asthma attack
salbutamol x3 = 10 puffs, 10 minute break, 10 puffs, 10 minutes break, 10 puffs
nebulised
IV salbutamol, IV aminophylline, IV magnesium sulfate second line
Moderate exacerbation of asthma requiring admission mx
inhaler with space
no magnesium sulfate
Mild exacerbation or moderate exacerbation not requiring admission
no hospital admission
inhaler with spacer
no ipratropium bromide, no magnesium sulfate
return to SABA up to 4x a day
consider initiating montelukast in children >2 years old