Respiratory Flashcards
describe what croup is (laryngotracheobronchitis)
usually result of a viral infection (most commonly parainfluenza type 1) causing mucosal inflammation of larynx, trachea and bronchi, increased airway secretions, and subglottic oedema-potentially dangerous in young children due to critical tracheal narrowing.
usually nose or nasopharyngeal infection initially
VC movement impaired producing barking cough and hoarseness.
most common cause of croup?
parainfluenza virus type 1
also types 2,3 and 4 role in aetiology but 1 most responsible
in children with a pattern of recurrent croup, what might this be related to?
atopy
*subglottal oedema may have an allergic rather than infective aetiology.
epidemiology of croup?
peak incidence in children of 2 years of age
but occurs from 6mnths to 6yrs (but also rarely adolescenets and adults)
boys more commonly than girls
commonest in autumn and spring
presenting features of croup?
onset over days with preceding corzya e.g. runny nose, sore throat, cough and fever before development of barking cough, harsh rasping stridor and hoarse voice.
hoarse cry
stridor may appear to become acutely worse with assoc. laryngeal spasm
symptoms often start and are worse at night.
what features in croup patient should alert you that there may be high risk of complete airway occlusion?
in a pt with previous resp distress signs including tachypnoea and intercostal recession who appears to be improving with apparent improvement in stridor and disappearance of intercostal recession, but child appears to be deteriorating.
also if there is drowsiness, lethargy and cyanosis in pt with increasing resp distress should alert to impending resp failure.
how long do pts tend to be unwell with croup?
illness typically lasts for about 3-7 days, but can persist for up to 2 wks.
croup causative organisms other than parainfluenza viruses?
RSV adenoviruses rhinoviruses enteroviruses measles metapneumovirus influenza A-cause of severe resp disease, and B mycoplasma pneumoniae coronovirus NL63
differing features between croup and acute epiglottitis?
onset: croup over a few days, epiglottitis over hrs
preceding coryza in croup
severe barking cough in croup, absent or slight cough in epiglottitis
hoarse voice, cry in croup and muffled voice, reluctance to speak in epiglottitis
stridor harsh and rasping in croup, soft whispering stridor in epiglottitis
drooling saliva in epiglottitis, absent in croup
unable to drink in epiglottitis
fever more than 38.5 degrees C in epiglottitis
appear toxic, very ill in epiglottitis, unwell in croup
how is bacterial tracheitis different from croup?
child has high fever, appears toxic and has rapidly progressive a.way obstruction with copious thick airway secretions
require IV Abx tment, and intubation and ventilation if required
cause of bacterial tracheitis?
staphylococcus aureus
how is severity of upper airways obstruction best assessed?
clinically by degree of chest retraction and degree of stridor, so looking at degree of subcostal, intercostal and sternal recession is more useful than measuring RR of pt.
how can croup severity be assessed?
Wesley clinical scoring system-score more than 6 indicating severe croup.
Severity assessed and graded on stridor-inspiratory and expiratory, palpable pulsus paradoxus-palpable decrease in pulse volume with abnormal BP decrease in inspiration and recession, cyanosis, confusion and drowsiness.
features of mild croup?
Inspiratory stridor present
Occasional barking cough, child happy to play
indications for hospital admission in croup?
consider if any of following present:
hx of severe obstruction, or previous severe croup, or known structural upper airways abnormalities e.g. laryngomalacia, tracheomalacia, vascular ring, or Downs which increase risk of severe croup developing
child under 6 mnths of age
immunocompromised
inadequate fluid intake, or refusing liquids
poor response to initial tment
uncertain diagnosis
significant parental anxiety, late evening or night time pres. or child’s home long way from hosp. or parents have no transport.
arrange immediate admission is suspect serious disorder:
bacterial tracheitis, epiglottitis, peritonisillar abscess, retropharyngeal abscess, laryngeal diphtheria, FB, hypocalcaemic tetany, angioneurotic oedema, corrosive ingestion
and if moderate or severe croup, or impending resp failure-altered conscious level, pallor, dusky appearance, tachycardia.
investigations in croup?
not usually needed for diagnosis
low SpO2 (less than 95%) indicates sign resp impairment
CXR-steeple sign-narrowing underneath larynx
throat swab-rapid influenza A test, but can distress child
direct or indirect laryngoscopy if atypical course of illness or reason to suspect congenital or alternative cause for upper airway obstruction.
croup management?
keep child as calm and as comfortable as possible
paracetamol or ibuprofen to control discomfort from symptoms or fever
adequate fluid intake
humidified O2 if required-humidified to reduce airway irritation, maintain SpO2 above 93%.
oral dexamethasone (syrup?)-0.15mg/kg, given to all children regardless of croup severity, should be given before transfer to hosp in moderate and severe croup, in hosp can give dexamethasone (PO or IM), prednisolone 1-2mg/kg or nebulised budesonide 2mg to reduce symptoms, and can rpt dose after 12 hrs.
nebulised adrenaline if moderate to severe distress, 400micrograms/kg, max 5mg, rpt after 30mins if necessary.
croup complications?
significant AIRWAY OBSTRUCTION
bacterial superinfection e.g. S.aureus, group A strep, moraxella catarrhalis, causing pneumonia or bacterial tracheitis
pulmonary oedema, pneumothorax, lymphadenitis, otitis media
DEHYDRATION if can’t maintain adequate fluid intake.
usual cause of bronchiolitis?
RSV
note RSV and human metapneumovirus dual infection assoc. with severe bronchiolitis
infants most at risk of severe bronchiolitis?
those born prematurely who develop BPD or with other underlying lung disease e.g. CF, or have congenital heart disease.
most common causes of stridor in child?
croup inhaled FB laryngomalacia or congenital airway abnormality epiglottitis bacterial tracheitis
presenting features of bronchiolitis?
sharp, dry cough and increasing SOB, preceded by coryzal symptoms-mild rhinorrhoea, cough, fever-many infants don’t progress past initial viral URTI features
cough and dyspnoea develop over 1-2 days in those that progress to LRT features
feeding difficulty assoc. with increasing SOB
apnoeas in infants younger than 4mnths
vomiting, irritability
o/e: tachypnoea mild conjunctivitis, pharyngitis subcostal and intercostal recession nasal flaring chest hyperinflation:prominent sternum and liver displaced downwards, spleen may also be palpable fine end-inspiratory crackles high pitched expiratory more so than inspiratory wheeze tachycardia cyanosis or pallor
results of CXR in bronchiolitis?
unnecessary innvestigation in straight forward cases
if perfromed, typically shows lung hyperinflation: more than 8-10 posterior ribs, horizontal ribs, diaphragm flattening, increased hilar bronchial markings, due to small airway obstruction and closure, air trapping and atelectasis. also patchy infiltrates.
epidemiology of bronchiolitis?
disease of the very young, usually between 2 and 6 months old, uncommon after 1 year of age
peak incidence in winter mnths
most common cause of acute resp failure in UK paediatric ICUs?
bronchiolitis
RFs for bronchiolitis?
passive smoke, part. maternal
overcrowding
nursery attendance
older siblings
RFs for severe bronchiolitis and/or complications?
prematurity low birth weight age less than 12 wks CLD-chronic lung disease congenital heart disease insulin dependent DM congenital defects of airways Downs epilepsy immunocompromise neurological disease with hypotonia and pharyngeal discoordination
investigations in bronchiolitis?
pulse oximetry
NP aspirate-RSV rapid testing-enable isolation or cohort arrangements and prevent further unnecessary testing, viral cultures for RSV, influenza A and B, parainfluenza and adenovirus.
CXR if diagnostic uncertainty or atypical course, but should NOT be routinely performed as changes may mimic pneumonia and should not be used to determine need for Abx.
blood and urine culture if toxic appearance or fever more than 38.5 degrees C
blood gas analysis, usually capillary, only in severe disease to identify hypercarbia when additional ventilatory support is considered
following infection with what organism is bronchiolitis more likely to result in permanent airway damage (bronchiolitis obliterans)?
adenovirus
management of bronchiolitis?
most children have mild self-limiting disease that can be managed at home with supportive measures, paying attention to nutrition, fluids and temperature control, usually disease lasts 7-10 days, must ensure parents know how to spot deterioration e.g. infant feeding less and becoming lethargic.
secondary care: supportive tment still mainstay, including O2 and NG feeding where necessary, give O2 if SpO2 persistently less than 92%
can give high flow O2 with vapotherm
other tments are of uncertain benefit: bronchodilators, corticosteroids, racemic adrenaline, and are NOT recommended by NICE.
continuous CPAP can be considered if impending resp failure
perform upper airway suctioning in children presenting with apnoea, even if no obvious upper airway secretions
ensure good infection control-hand washing, aprons, infected pt isolation
indications for hosp r/f in bronchiolitis?
poor feeding (less than 50% usual intake over prev. 24 hrs) which is inadequate to maintain hydration lethargy hx of apnoea RR more than 70 breaths/min cyanosis nasal flaring or grunting severe chest wall recession sats 94% or less uncertainty regarding diagnosis where home care or rapid r/v cannot be assured.
what do up to half of infants suffer from after episode of bronchiolitis?
recurrent episodes of cough and wheeze
bronchiolitis is assoc. with an increased risk of asthma but uncertainty whether it causes this
indications for immunoprophylaxis e.g. palivizumab against RSV?
children under 2yrs with CLD, who have required at least 28 days of supplemental O2 from birth or who are receiving home O2
infants under 6 mnths with L to R shunts, haemodynamically significant congenital heart disease or pulmonary HTN.
children under 2 yrs with severe congenital immunodeficiency
give 1st dose before RSV season
what condition do most wheezy preschool children have?
virus-associated wheeze/episodic viral wheeze/wheezy bronchitis
viruses trigger small airway narrowing due to inflammation and immune response to viral infection-release of smooth muscle constrictors e.g. histamine, and mucus production due to infectious agent.
may be decreased lung function from birth with small a.way diameter in transient early wheezers which may be assoc. with maternal smoking or prematurity.
transient early wheezing usually resolves by 5 yrs of age, probably as airway size is increased.
*vs bronchiolitis-usually onset in children in 1st 2-6mnths of life.
clinical features of cystic fibrosis in infancy?
meconium ileus in newborn period-intestinal obstruction with vomiting, abdo distension and failure to pass meconium in 1st 24-48hrs, tx with gastrografin enemas, but most need surgery. prolonged neonatal jaundice* failure to thrive recurrent chest infections malabsorption, steatorrhoea
incidence of CF?
1 in 2500 live births
carrier rate 1/25
investigation to diagnose pancreatic insufficiency in CF patients?
low elastase in the faeces
URT and LRT complications of cystic fibrosis?
sinusitis
nasal polyps-rhinorrhoea, nasal obstruction/blockage
bronchiectasis
ABPA
pneumothorax
recurrent haemoptysis-blood vessel erosion with recurrent infections?
recurrent and persistent bacterial infection-older children should have regular lung function monitoring with spirometry
persistent productive cough
features of CF o/e of the chest?
chest hyperinflation-?barrel deformity
scars-?pneumothorax, bilateral lung transplant, venous access port-?peripheral venous lung line for IV Abx in infection, can implant central venous catheter with SC port (e.g. portacath), to simplify access.
harrison’s sulcus-horizontal groove along lower border of thorax
poor chest expansion?
palpable pulm valve closure?
RV overactivity, ?hypertropy-L parasternal heave
coarse inspiratory crepitations
expiratory wheeze
loud S2-pulmonary HTN
gallop rhythm-cor pulmonale
aims of management in CF?
prevent lung disease progression
maintain adequate nutrition and growth
how can regular flow of bile be promoted in CF patients in trying to prevent liver disease?
ursodeoxycholic acid
