Paeds - Respiratory (Chronic Conditions) Flashcards
Chronic Asthma
Risk Factors and Precipitating Factors
Clinical Features
Preschool Wheeze
Investigations
1.) Risk Factors and Precipitating Factors
- FH of asthma or atopy, parental smoking
- low birth weight, prematurity
- hx of viral bronchiolitis, atopic dermatitis
- triggers: cold air and exercise, pollution, allergen exposure, NSAIDs (↑leukotrienes), beta-blockers
2.) Clinical Features - wheezing which can be:
- infrequent episodic, frequent episodic (2-6 wkly), persistent (most days and may have disturbed nights)
- may have an associated cough and SOB
- diurnal variability: worse at night and early morning
- bilateral widespread “polyphonic” wheeze
3.) Preschool Wheeze - up to 50% of kids will have had at least one episode of wheeze before the age of 5
- wheeze is proceeding by coryzal sx (due to infection w/ human rhinovirus or respiratory syncytial virus (RSV))
- most will outgrow their wheeze but it’s difficult to predict who will go on to have asthma
4.) Investigations
- spirometry/PEFR: obstructive pattern (FEV1:FVC <70%) which is reversible with a bronchodilator (>12% improvement)
- spirometry is unreliable in <5s so asthma is a clinical diagnosis
- exhaled nitric oxide (ENO) testing: +ve test is >35parts per billion (also raised in allergic rhinitis), only offered in uncertain diagnosis (normal spirometry or negative bronchodilator reversibility), can be used to measure control
- other investigations: bronchial provocation tests, exercise testing, skin prick testing, CXR (for baseline)
Guidelines for Asthma Management
Assessment and Good Symptom Control
Newly Diagnosed Asthma
Regular Preventer
Initial Add-On
Persistent Poor Control
Other Drugs
1.) Assessment - symptoms, lung function, optimise inhaler technique and adherence, eliminate triggers
- review at 6-8wks to assess response to treatment
- symptom diary is preferred in children > spirometry
2.) Good Symptom Control - overarching aims
- <2/wkly daytime sx and using SABA < 2x a week
- full school attendance, no sleep disturbance, no limitation on daily activities, no exacerbations, and maintaining normal lung function.
1.) Newly Diagnosed Asthma - SABA PRN
- INH salbutamol PRN
2.) Regular Preventer - SABA PRN + very low paediatric dose of ICS BD
- if SABA alone is ineffective or new asthma with symptoms >3x a week or waking at night w/ asthma
- ICS is usually beclomethasone
- under 5: LTRA (PO montelukast) instead, side effects:
headache, stomach-ache, behaviour changes, possible suicidal ideation
3.) Initial Add-On - SABA PRN + ICS BD + LABA/LTRA
- LABA first in children >5, LTRA in children <5
- if no response to LABA, consider stopping it
4.) Persistent Poor Control
- increase to low dose ICS OR add LTRA in kids >5
5.) Other Drugs - under a respiratory paediatrician
- used if no control with high dose ICS
- trial of biological agents: omalizumab (MAB for IgE to reduce free IgE)
- only useful if evidence of allergic sensitisation to a perennial aeroallergen (house dust mite) and a raised serum total IgE.
Use of Inhalers
Inhaler Technique w/o Spacer
Inhaler Technique w/ Spacer
Side Effects of Inhaled Corticosteroids
1.) Inhaler Technique w/o Spacer
- remove the cap then shake the inhaler
- sit/stand up straight and lift the chin slightly
- fully exhale then make a tight seal around the inhaler
- steadily inhale for 3-4s whilst pressing the canister
- hold the breath for 10s or as long as possible
- wait 30 seconds before giving a further dose
- rinse the mouth after using a steroid inhaler
2.) Inhaler Technique w/ Spacer - same steps but
- make a seal around the mouthpiece (or place mask over face) then spray the dose into the spacer
- take steady breaths in and out 5 times until the mist is fully inhaled
- spacers should be cleaned once a month, avoid scrubbing the inside, allow them to air dry to avoid creating static which can interact with the mist and prevent the medication being inhaled
3.) Side Effects of Inhaled Corticosteroids
- cough, sore mouth/throat, hoarse voice, oral thrush
- reduction in height: only when used long term (>12m) and with higher doses, however, poorly controlled asthma could lead to higher doses of oral steroids which will have a larger impact on development
Bronchiectasis
Pathophysiology
Clinical Features
Investigations
Management
1.) Pathophysiology - chronic inflammation causing irreversible dilation of one or more bronchi
- deformed bronchi have poor mucus clearance so increased susceptibility to bacterial infections
- organisms: H. influenzae, P. aeruginosa, Moraxella catarrhalis, fungi, mycobacteria, S.aureus (w/ CF)
2.) Clinical Features
- chronic cough and daily sputum production
- SOB on exertion, chest pain, haemoptysis,
- fever, fatigue, weight loss, recurrent LRTIs,
- examination: coarse inspiratory crackles (rales), wheeze (associated with CF), finger clubbing
- exacerbation: deterioration in 3+ key sx for >48hrs: cough, SOB, fatigue, haemoptysis, sputum purulence
3.) Investigations - for the diagnosis and cause
- CXR: can be normal or may show bronchial wall thickening or airway dilatation
- HR-CT (gold): signet ring sign (dilated bronchus is larger than the accompanying pulmonary artery)
- bronchoscopy: for those with focal bronchiectasis on HR-CT or evidence of possible airway abnormality
- underlying cause: sputum culture, Cl sweat test, FBC, HIV test, immunoglobulin panel, abs for vaccinations
- pulmonary function tests: FEV1:FVC < 70%, elevated RV:TLC (air trapping), ↓diffusing capacity for CO
4.) Management - treat the underlying cause
- physiotherapy: mucus/airway clearance
- Abx for acute exacerbations ?prophylactic Abx
- vaccines e.g. flu, bronchodilators (if wheezing)
- pulmonary rehab: if MRC dyspnoea score 3+
- complications: recurrent infection, lung abscess, pneumothorax, life-threatening haemoptysis, poor growth and development
Causes of Bronchiectasis
Post Infective
Immune Deficiency
Mucociliary Clearance Defects
Obstruction
Toxic Insult
Others
1.) Post Infective - bronchial damage causes bronchiectasis after a severe LRTI:
- S.pneumoniae, S.aureus, adenovirus, influenza virus, measles, Bordetella pertussis (whooping cough), TB
2.) Immune Deficiency - increased infection risk
- hypogammaglobulinaemia, common variable immune deficiency (CVID) or IgA/IgG deficiency
- secondary immune deficiency (HIV, malignancy)
- ataxia telangiectasia
3.) Mucociliary Clearance Defects
- cystic fibrosis (most common cause of bronchiectasis)
- primary ciliary dyskinesia, Young’s syndrome, Kartagener syndrome
4.) Obstruction
- foreign bodies, tumours, extrinsic lymph nodes
5.) Toxic Insult
- gastric aspiration, inhalation of toxic chemicals/gases
6.) Others - alpha-1 antitrypsin deficiency, allergic bronchopulmonary aspergillosis,
- IBD, RA (associated with bronchiectasis)
Aetiology and Pathophysiology of Cystic Fibrosis
Aetiology
Respiratory Tract
Pancreas
Gastrointestinal Tract
Reproductive Tract
1.) Aetiology - multisystem, autosomal recessive disorder affecting mucus glands all over the body
- caused by a genetic mutation/defect in the CFTR gene on chromosome 7 affecting chloride channels
2.) Respiratory Tract - defective CFTR disrupts Cl- movement and reduces Na/water reabsorption
- this impairs mucus clearance as secretions are less watery so there is reduced airway surface liquid
- this provides a niche for bacterial growth making CF patients increasingly susceptible to airway infections
3.) Pancreas - defective CFTR leads to occlusion of the pancreatic duct in-utero, causing permanent damage
- this causes pancreatic insufficiency in CF patients
- over time, the endocrine pancreas is also affected which can lead to CF-related diabetes mellitus
4.) GI Tract - defective CFTR causes the SI to secrete viscous mucus –> bowel obstruction in-utero
- this causes meconium ileus in the infant
- CF can also cause cholestasis in the biliary tree which can result in neonatal jaundice
- in later life, it can cause distal intestinal obstruction syndrome (DIOS) and CF-related liver disease
5.) Reproductive Tract - defective CFTR leads to congenital absence of the vas deferens causing:
- male infertility (98% of men): healthy sperm but can’t get from the testes to the ejaculate
- reduced fertility in women due to thicken cervical mucus but they can still get pregnant
Clinical Features and Diagnosis of Cystic Fibrosis
Presentation of Cystic Fibrosis
Other Symptoms and Signs of Cystic Fibrosis
Chloride Sweat Test
Other Investigations
1.) Presentation of Cystic Fibrosis - depends on the age
- neonates: meconium ileus (no passing of meconium w/in 24hrs, abdo distension, and bilious vomiting), positive in the newborn heel prick test, failure to thrive, prolonged neonatal jaundice
- infancy: failure to thrive, recurrent chest infections, steatorrhoea (pancreatic insufficiency)
- childhood: rectal prolapse, nasal polyps, sinusitis
- adolescence: DM (pancreatic insufficiency), chronic lung disease, DIOS, gallstones, liver cirrhosis
2.) Other Symptoms and Signs of Cystic Fibrosis
- chronic cough, thick sputum production, recurrent RTIs
- abdominal pain and bloating, steatorrhea
- concentrated salt in sweat, failure to thrive
- signs: nasal polyps, finger clubbing, crackles and wheeze on auscultation, abdo distension
3.) Chloride Sweat Test - diagnostic w/ fitting clinical hx, may be supported w/ 2 identified mutations
- measures the electrolyte concentration in a sweat sample (collected by pilocarpine iontophoresis)
- Cl >60mM is suggestive of CF, 40-60mM is borderline (needs repeating)
- test can fail if there’s an insufficient sample (small baby)
- false +ve: malnutrition, adrenal insufficiency, glycogen storage diseases, nephrogenic DI, hypothyroidism, hyperparathyroidism, G6PD, ectodermal dysplasia
- false -ve: skin oedema due to hypoalbuminaemia secondary to pancreatic exocrine insufficiency
4.) Other Investigations
- annually: CXR or CT, OGTT (teenagers), LFTs, clotting, bone profile
- cough/sputum sample at every clinical encounter
- lung function: spirometry/lung clearance index
- faecal elastase, HR-CT, genetic analysis
Management of Cystic Fibrosis
Nourishment and Exercise
Managing/Preventing Airway Infections
Use of Antibiotics
Other
1.) Nourishment and Exercise
- exercise improves resp function and reserve, and helps clear sputum
- high-calorie diet is required due to malabsorption, ↑respiratory effort, coughing, infections, physiotherapy
- pancreatic insufficiency: high-fat meals with enzyme supplementation (Creon) for every meal, vitamin A/D/E/K supplements
- poor weight gain: build up milkshakes to supplement meals, supplemental enteral feeding (via gastrostomy) in extreme cases of malnutrition
2.) Managing/Preventing Airway Infections
- active segregation of CF patients reduces cross-infection esp those w/ Pseudomonas and TB
- vaccinations: e.g. pneumococcal, influenza, varicella
- chest physio (daily) to clear mucus and ↓infection/colonisation risk
- continual sputum samples (or cough swabs) to identify colonising organisms: common ones include S.aureus, H.influenzae, P.aeruginosa
- treat infections w/ at least 2wks of high dose Abx
- Pseudomonas infection has ↑morbidity/mortality as it is harder to eradicate due to antibiotic resistance
3.) Use of Antibiotics
- high doses for at least 2wks if oral
- IV abx if not responsive to oral antibiotics, or as part of some pseudomonas eradication regimens
- need repeat culture to ensure the infection is cleared
- prophylactic flucloxacillin used in infants (until 3yrs) to protect against bacterial infections (esp S.aureus)
- chronic Pseudomonas infections treated w/ long-term inhaled abx (tobramycin) to suppress its growth
- regular azithromycin: given to patients with deteriorating lung function or repeated pulmonary exacerbations to help reduce exacerbations and improve lung function
4.) Other
- annual review: clinical sx, abx courses, sputum samples, bloods (FBC, U+Es, LFTs, clotting, HbA1c, vit A/D/E levels), lung function tests, CXR, OGTT (>12s)
Complications of Cystic Fibrosis
Respiratory Tract
Gastrointestinal Tract
Endocrine
Other
1.) Respiratory Tract
- bronchiectasis, haemoptysis, pneumothorax
- pulmonary hypertension and right heart strain
- respiratory failure (occurs eventually in CF patients)
- nasal polyps which may be associated with sinusitis
- allergic bronchopulmonary aspergillosis (ABPA): an immune response to Aspergillus spp, initially treated w/ oral corticosteroids (prednisolone) and itraconazole
2.) Gastrointestinal Tract
- cholestasis, gallstones, liver cirrhosis, liver disease
- rectal prolapse: may be due to frequent passage of bulky stools, initially tx w/ laxative and pancreatic enzyme replacement to minimise straining
- distal intestinal obstruction syndrome (DIOS): distal ileum obstruction due to a slower intestinal tract, sx: colicky abdo pain, palpable mass in the RLQ
3.) Endocrine
- CF-related diabetes: associated with a rapid decline in lung function and disease progression, sx inc weight loss, anorexia, ↓lung function, DKA is rarer as there is not a lack of insulin
- delayed puberty: avg delay of 2 years, can lead to ↓ bone mineral density, predisposing children to fractures in adolescence and adulthood
4.) Other
- arthritis, reduced bone mineral density
- Sub or infertility in later adolescence/adulthood
Obstructive Sleep Apnoea
Pathophysiology
Clinical Features
Complications
Differential Diagnosis
1.) Pathophysiology - intermittent and recurrent collapse of the upper airways during sleep which is defined as:
- ≥5 respiratory events per hour (measured by polysomnography) with associated symptoms of OSA
- risk factors: obesity (main risk factor), male, middle-aged, smoking, alcohol, use of sedative drugs
- in children, tonsillar and adenoid enlargement can cause partial obstruction of the upper airways –> OSA
2.) Clinical Features
- witnessed sleeping disturbance: choking episodes or observed apnoea (breathing stops whilst asleep)
- excessive daytime sleepiness and ↓concentration:
can affect driving, work, relationships, mood
- snoring, morning headache, unrefreshed from sleep
- restlessness, personality changes, reduced libido
- enquire about sx of H+N cancers in assessment
3.) Complications
- must inform the DVLA if on CPAP treatment
- ↑risk of cardiovascular co-morbidities: HTN, HF, MI, stroke (risk reduces with successful treatment of OSA)
- ↓QoL: effects on memory, cognitive function, mood.
4.) Differential Diagnosis
- daytime sleepiness: depression/anxiety, narcolepsy, hypothyroidism, medication (sedatives, SSRIs etc)
- nocturnal choking/gasping: GORD, nocturnal asthma, or heart failure (PND or orthopnoea)
Assessment and Management of OSA
Investigations
Non-Pharmacological Intervention
Surgical Interventions
1.) Investigations - diagnosed via sleep studies
- exclude differentials: TFTs, CXR/ECG
- polysomnography: measures no of apnoeic/hyponoeic episodes per night (Apnoea-Hypopnoea Index, AHI)
- AHI determines severity: mild = 5-14 episodes/hour, moderate = 15-30 episodes, severe = >30 episodes
- Epworth Sleepiness Scale: assesses impact of OSA, mild = 11-14, moderate = 15-18, severe = >18/24
2.) Non-Pharmacological Intervention
- lifestyle: weight loss, ↑exercise, ↓smoking, ↓alcohol
- regular calculation of cardiovascular risk profile
- intra-oral devices e.g. mandibular advancement can be tried in mild OSA or if patient’s cannot tolerate CPAP
- CPAP (first-line for mod-severe OSA): provides positive pressure of air at night to keep airways open
- CPAP can actually ↓BP but has a low compliance due to discomfort and patients feeling claustrophobic
3.) Surgical Interventions
- tonsillectomy and/or adenoidectomy in children with OSA due to tonsillar and/or adenoid enlargement
- uvulopalatopharyngoplasty (UPPP) or laser-assisted UPPP (LAUP) (removes excess tissue to widen airway)
- radiofrequency ablation of tongue base, suspension of the hyoid bone, orthognathic (jaw) surgery
