Respiratory Flashcards
What is bronchopulmonary dysplasia?
a form of chronic lung disease that affects newborns, most often those who are born prematurely and need oxygen therapy. In BPD the lungs and the airways (bronchi) are damaged, causing tissue destruction (dysplasia) in the tiny air sacs of the lung (alveoli)
Abnormal pul development,
Prolonged mechanical ventilation
↓alveoli no, interstitial thickening, abnormal pul vasculature development, pul oedema + atelectasis.
Features of bronchopulmonary dysplasia?
Severe retractions
Audible rales, crackles
Intermittent expiratory wheeze if airway narrow from scar formation, constriction, mucus retention, collapse/ oedema.
O2 desats during feeds
Asthma in childhood
Complications of bronchopulmonary dysplasia?
Resp distress Ventilator dependence, pul hypotension, subglottic stenosis Feeding problems poor weight gain Severe bronchiolitis, GORD Low IQ > CP
Investigations for bronchopulmonary dysplasia?
O2 ↓ test, need for O2 supplementation. O2 sats <90% within 60 mins of being placed in room air.
CXR: diffuse haziness, exudative fluid, multicystic sponge like, areas pf alternating oedema, pul scarring emphysema, Hyperinflation, rounded radiolucent mass alternating with thin denser lines
Histology: necrotising bronchiolitis with alveolar fibrosis
Management of bronchopulmonary dysplasia?
Supportive
Nutritional supplementation
Fluid restriction
Diuretics
O2
Gentle ventilation low vol/ O2 conc
Steroids
Surfactant
Almost all weaned by 1 yr ↑ risk of bronchiolitis > give palivizumab monthly + LT risk of COPD
What is neonate respiratory distress syndrome?
happens when a baby’s lungs are not fully developed and cannot provide enough oxygen, causing breathing difficulties. It usually affects premature babies.
not enough surfactant, so lungs collapsing, progressive + diffuse atelectasis
Damage of epithelial cells can be permanent
24-28 wks deffo. 50% at 32 wks
RF - premature, mother DM, LBW, lungs not properly developed, 2nd twin, CS, 2’ to other pulmonary pathology > meconium, perinatal asphyxia, pul hypoxia
Features of neonate respiratory distress syndrome?
Worsening tachypnoea >60/min 1st 4 hrs of birth
↑inspiratory effort
Grunting
Flaring of nostrils
Intercostal recession
Cyanosis
Resp failure, reinfilation between breaths makes baby very tired.
Complications of neonate respiratory distress syndrome?
Death
Pneumothorax: prolonged pressure from ventilation
Hypoglycaemia, acidosis + systemic compromise.
Chronically: BPD, IVH, retinopathy of prematurity
Investigation and management of neonate respiratory distress syndrome?
CXR: diffuse granular patterns, air bronchograms, low lung volume, ground glass, heart border indistinct Pneumothoraxes.
ABG: hypoxaemia, hypercapnia
Prevention: beta/dexamethasone prenatally. If postnatal risk of GI bleed, intestinal perf, hypoglycaemia, HBP, HCM, poor growth.
CPAP, intubation, intratraceal surfactant therapy
What is pulmonary hypoplasia?
a condition in which the lungs are abnormally small, and do not have enough tissue and blood flow to allow the baby to breathe on his or her own.
Causes - Oligohydramnios, PROM, congenital diaphragmatic hernia
Underdeveloped lungs, ↓no/ size of bronchopul seg/ alveoli
Potter’s: bilat renal agenesis, oligohydramnios, low set ears, beaked nose, ↓lung expansion, ↓mechanical stretching
SOL: diaphragmatic hernia, congen cyst adenomatoid formation, fetal hydronephrosis, mediastinal tumour, caudal regression syndrome, dextrocardia, sacrococcygeal teratoma.
Features of pulmonary hypoplasia?
Infants with persistent tachypnoea ± feeding difficulties
Poor fetal movement, AF leakage, oligohydramnios
Asymptomatic
Severe resp distress
Small bell shaped chest
Heart displacement
↓/absent BS
Investigations and management of pulmonary hypoplasia?
Fetal USS
Amnioinfusion: instilling isotonic fluid into amniotic cavity
Amniopatch: intra-amniotic injection of plt cryoprecipitate, seal amniotic fluid leak
Resp support
What is croup?
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. Other causes - RSV, adenovirus, Diptheria
6m-3yrs
more common in autumn
Features of croup?
stridor
barking cough (worse at night)
fever
coryzal symptoms
Severity of croup?
Mild
Occasional barking cough
No audible stridor at rest
No or mild suprasternal and/or intercostal recession
The child is happy and is prepared to eat, drink, and play
Moderate
Frequent barking cough
Easily audible stridor at rest
Suprasternal and sternal wall retraction at rest
No or little distress or agitation
The child can be placated and is interested in its surroundings
Severe
Frequent barking cough
Prominent inspiratory (and occasionally, expiratory) stridor at rest
Marked sternal wall retractions
Significant distress and agitation, or lethargy or restlessness (a sign of hypoxaemia)
Tachycardia occurs with more severe obstructive symptoms and hypoxaemi
When to admit a child with croup?
Moderate or severe croup
< 6 months of age
known upper airway abnormalities (e.g. Laryngomalacia, Down’s syndrome)
uncertainty about diagnosis (important differentials include acute epiglottitis, bacterial tracheitis, peritonsillar abscess and foreign body inhalation)
Investigations for croup?
the vast majority of children are diagnosed clinically
however, if a chest x-ray is done:
a posterior-anterior view will show subglottic narrowing, commonly called the ‘steeple sign’
in contrast, a lateral view in acute epiglottis will show swelling of the epiglottis - the ‘thumb sign’
Westley scale 0-17 - mainly for research, not clinically
3-7: moderate
8-11: severe
12+: resp failure
Management of croup?
CKS recommend giving a single dose of oral dexamethasone (0.15mg/kg) to all children regardless of severity
prednisolone is an alternative if dexamethasone is not available
humidified O2
fluids, antipyretics
Emergency treatment
high-flow oxygen
nebulised adrenaline
intubation if impending respiratory failure
What is acute epiglottitis?
Fluid, inflam cell accumulation, rapid progressive swelling of epiglottis, supraglottic larynx, airway narrows, ball-valve curling.
Haem influenzae type B
RF: unimmunised, mucosal trauma (burns, caustic substance, FBI), 6-12y/o, DM, substance abuse, BMI >25
Don’t agitate child incl attempt to examine throat = can precipitate obstruction
Features of acute epiglottitis?
rapid onset
high temperature, generally unwell
stridor
drooling of saliva
‘tripod’ position: the patient finds it easier to breathe if they are leaning forward and extending their neck in a seated position
3D’s - dysphagia, drooling, distress
Diagnosis of acute epiglottitis?
made by direct visualisation (only by senior/airway trained staff)
However, x-rays may be done, particularly if there is concern about a foreign body:
a lateral view in acute epiglottis will show swelling of the epiglottis - the ‘thumb sign’
in contrast, a posterior-anterior view in croup will show subglottic narrowing, commonly called the ‘steeple sign’
Management of acute epiglottitis?
immediate senior involvement, including those able to provide emergency airway support (e.g. anaesthetics, ENT)
> endotracheal intubation > may be necessary to protect the airway
if suspected do NOT examine the throat due to the risk of acute airway obstruction
the diagnosis is made by direct visualisation but this should only be done by senior staff who are able to intubate if necessary
oxygen - humidified in severe intubation, if not possible then cricothyroidotomy
intravenous antibiotics - Cefotaxime, ceftriaxone, clinda/ vancomycin. Pen allergic: chloramphenicol
Oral Abx - co-amoxiclav, cefaclor
IV steroids - reduce swelling
Hib vaccine
What is laryngomalacia?
Congenital abnormality of the larynx. aryepiglottic folds shorter than normal, cause folding of epiglottis in omega shape that prolapses during inspiration.
Infants typical present at 4 weeks of age with:
stridor
Features of laryngomalacia?
Inspiratory stridor more marked when upset/ feeding
Noisy resps
Breathing difficulties
Impaired growth + development caused by hypoventilation
GO reflux
Swallowing problem + choking
Investigation and management of laryngomalacia?
Laryngoscopy or bronchoscopy - omega shaped epiglottis
Can resolve spont as throat muscles strengthen by age 2
Supplemental O2 if hypoxemic
Surgical Tx: tracheotomy or supraglottoplasty
What is whooping cough?
an infectious disease caused by the Gram-negative bacterium Bordetella pertussis.
It typically presents in children. There are around 1,000 cases are reported each year in the UK.
infants are routinely immunised at 2, 3, 4 months and 3-5 years. Newborn infants are particularly vulnerable, which is why the vaccination campaign for pregnant women was introduced - Women who are between 16-32 weeks pregnant will be offered the vaccine.
neither infection nor immunisation results in lifelong protection - hence adolescents and adults may develop whooping cough despite having had their routine immunisations
Features of whooping cough?
2-3 days of coryza precede:
coughing bouts: usually worse at night and after feeding, may be ended by vomiting & associated central cyanosis
inspiratory whoop: not always present (caused by forced inspiration against a closed glottis)
infants may have spells of apnoea
persistent coughing may cause subconjunctival haemorrhages or even anoxia leading to syncope & seizures
symptoms may last 10-14 weeks* and tend to be more severe in infants
marked lymphocytosis
Diagnostic criteria of whooping cough?
Whooping cough should be suspected if a person has an acute cough that has lasted for 14 days or more without another apparent cause, and has one or more of the following features:
Paroxysmal cough.
Inspiratory whoop.
Post-tussive vomiting.
Undiagnosed apnoeic attacks in young infants
Investigations for whooping cough?
per nasal swab culture for Bordetella pertussis - may take several days or weeks to come back
PCR and serology are now increasingly used as their availability becomes more widespread
Complications of whooping cough?
subconjunctival haemorrhage
pneumonia
bronchiectasis
seizures
Management of whooping cough?
infants under 6 months with suspect pertussis should be admitted
in the UK pertussis is a notifiable disease
an oral macrolide (e.g. clarithromycin, azithromycin or erythromycin) is indicated if the onset of the cough is within the previous 21 days to eradicate the organism and reduce the spread
household contacts should be offered antibiotic prophylaxis
antibiotic therapy has not been shown to alter the course of the illness
school exclusion: 48 hours after commencing antibiotics (or 21 days from onset of symptoms if no antibiotics )
What is bronchiolitis?
a condition characterised by acute bronchiolar inflammation. > epithelial cells produce mucus, BVs vasodilate, leaky. Inflam + swelling, walls thicker + airway narrows. Dead cells + mucus in airway, mucus plugs, air trapping. Air diffuse into blood, atelectasis. Over inflation of lungs.
Respiratory syncytial virus (RSV) is the pathogen in 75-80% of cases. other causes - mycoplasma, adenoviruses.
may be secondary bacterial infection
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
more serious if bronchopulmonary dysplasia (e.g. Premature), congenital heart disease or cystic fibrosis
RF - <2, prev infection, daycare, ↓immunity, NM disorders, premie, CV malformation, airway malformation, smoking
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
When to immediately refer for bronchiolitis?
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.
When to consider referring to hospital with bronchiolitis?
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.
Investigation for bronchiolitis?
X-ray: atelectasis, patchy infiltrates, hyperinflation
Pos rapid viral testing
Largely clinical
immunofluorescence of nasopharyngeal secretions may show RSV
Management of bronchiolitis?
humidified oxygen is given via a head box and is typically recommended if the oxygen saturations are persistently < 92%
nasogastric feeding may be needed if children cannot take enough fluid/feed by mouth
suction is sometimes used for excessive upper airway secretions
Palivizumab: monoclonal Ig against RSV given monthly from RSV season for prematurely born infants, CLD, CHD
Paracetamol, ibuprofen
Intubation
Almost all recover, rarely progresses to broncholitis obliterans, permanent scarring of bronchioles, chronic cough/ wheeze
What is asthma?
↑airway responsiveness, reversible airway obstruction
Bronchoconstriction, smooth muscles of bronchioles spasm/ contract, mucus hypersecretion impaired mucociliary function, difficulty breathing.
Vasodilation of pul vasculature, cap permeability, oedema.
Triggers: air pollution, smoke, dust pet dander, cockroaches, mould, pollen, meds (aspirin, BB), faeces of dust mites, food eg peanut, wheat, industrial chemicals, infections.
RF: allergic sensitisation, atopic resp viral infections in early life (RSV or human rhinovirus), serum eosinophilia, FH, active / passive smoking, F>M, obesity, acid suppressing drugs in pregnancy, GORD, OSA.
Chronic: irreversible damage, smooth muscle hypertrophy, scarring + fibrosis, thickening of epithelial BM, narrows airway.
Features of asthma?
Cough/ dyspnoea: precipitated by allergen exposure, cold air, smoke Worse with laughing. May wake pts. Dry night cough
Recent URTI
Chest tightness, dyspnoea, difficulty breathing, wheezing
Curschmann spiral in sputum: spiral shaped mucus plugs, casts from small bronchi, blocks air exchange + inhaled meds from reaching inflam
Charcot-Leyden crystals sputum: needle shaped, breakdown of eosinophils
Tachypnoea, hyperinflated chest
Hyperresonant
Nasal polyps
Dyspnoea on exertion
Harrison’s sulci: rib deformity at insertion of diaphragm muscle caused by chronic resp difficulty
Complications of asthma?
Severe exacerbations
Airway remodelling
Oral candidiasis: 2° to use of
ICS
Dysphonia: 2° to use of ICS, laryngeal muscle spasms
Pneumothorax/ pneumomediastimum
Resp failure
Stunted growth due to steroids
Investigations for asthma?
FEV1:FVC <80% predicted
Reversibility: prebronchodilator spirometry (withhold SABA 4hrs, LABA 15 hrs), 15 mins after salbutamol. FEV-1 ^ by 200mls + 12%
FBC: ^IgE, neutrophilia, eosinophila.
Skin prick testing for allergies.
Sputum eosinophilia <3%
Niox machine: >40
Peak flow: exagg variation.
Mannitol challenge test: acts on inflam cells trigger release of mediators, cause bronchoconstriction in those with hyperreactivity. Do spirometry, inhale 🡩 conc of mannitol. Spirometry each time. When FEV1 🡫 15% of baseline define what degree of bronchial hyperreactivity
Attempt to measure PEF in all children aged > 5 years
Management of asthma in children?
Step 1: SABA
Step 2: if using >1 a day. ICS low dose
Step 3: add LTRA Theophylline/ zileuton, montelukast, zafirulast, sodium cromoglicate, nedocromil.
Step 4: add LABA, Review if should continue LTRA.
Step 5: SABA + switch ICS/LABA for maintenance + reliever therapy that includes paediatric low dose ICS.
Step 6: mod dose MART
Step 7: SABA + 1 of following, ↑ICS to paed high dose, either fixed dose regime or MART, trial additional drug e.g. theophylline, refer.
If child <5: 1st SABA
2nd: SABA + 8 wk trial of mod dose ICS, if don’t resolve review whether alternative diagnosis likely, if Sx resolved then reoccurred within 4wks of stopping ICS, restart ICS at paed low dose as maintenance. If Sx reoccurred beyond 4 wks stopping ICS, repeat 8 wk trial of paediatric mod dose of ICS.
3rd SABA, paediatric low dose ICS + LTRA.
4th stop LTRA + refer to paediatric asthma specialist
Features of moderate asthma attack?
SpO2 > 92%
PEF > 50% best or predicted
No clinical features of severe asthma
Features of severe asthma attack?
SpO2 < 92% PEF 33-50% best or predicted Can't complete sentences in one breath or too breathless to talk or feed HR> 125/min RR > 30/min Use of accessory neck muscles
Features of life-threatening asthma?
SpO2 <92% PEF <33% of best or predicted Silent chest Poor respiratory effort Altered consciousness Cyanosis
