Respiratory System

Respiratory System Development • Embryonic stage = 4 wks o ventral growth from foregut • Pseudoglandular = 5-16wks o Mesenchyme around respiratory bud à cartilage, muscle, connective tissue, lymph and vessels. o Branching is complete by 16 weeks • Canalicular = 16-24 wks o mesenchyme proliferation à growth on bronchioles • Terminal Sac stage = 22wks onward o Formation of alveoli with gas exchange surface à thinning of blood-gas barrier. o Type 2 pneumocyes produce surfactant from 24 wks o NB: oligohydramnios à lung hypoplasia e.g. Potter syn • Alveolar development continues until age 5-8yrs Respiratory Noises Snoring = inspiratory vibrations = hypopharynx obstructed due to decreased muscle tone Stridor – harsh inspiratory noises due to obstruction in larynx / trachea Rattley – mucus in hypopharynx e.g. UTRI Grunting – PEEP Wheeze – expiratory noise – very common especially in young children with viral illness Imaging Hyperinflation – e.g. bronchiolitis / asthma OR if unilateral e.g. FB/ball valve effect / lobar emphysema Consolidation – pus/blood/fluid + air bronchograms Oedema – fluid in fissures & effusion Collapse – no air bronchograms, rub crowding, loss Indication for CXR in children of volume Septic screen in under 5s (T> 39deg) Bronchiectasis – dilated walls – circles / tram lines Lobar Pneumonia Pleural fluid – meniscus with blunted angles Persistent consolidation ? Pleural effusion Control of respiration FU of lobar collapse / consolidation Medulla Inspiratory & expiratory à regular rhythm If afferent stimulus stops à irregular respiration Apneustic centre (lower pons) Gasps if no input from above Pneumotaxic centre (upper pons) Inhibits respiration during cycle à regulates rate (control of Ti) Cortex – voluntary control Limbic system – links to emotion e.g. anger / fear Central chemoreceptors Respond to H2 ions – increased à simulate, decrease à inhibit Therefore if chronic acidosis & compensation à reduced effect of raised CO2 Peripheral Chemoreceptors In carotid bodies & aortic bodies Increase breathing rate if low pH, high CO2 or low O2 Inspiration = intercostals /diaphragm +/- SCM & scalenes Expiration – passive = recoil, active = abdo mms Spirometry Generally capable from 5-6 yrs Obstruction e.g. asthma. Returns to normal after bronchodilators Restrictive deficit à Decreased Capacity Decreased FEV1 Normal tidal volume Decreased peak flow Restrictive V obstructive FVC = total amount of air exhaled in max expiration FEV1 = Forces expir vol in 1 second Restrictive pattern FVC and FEV1 are reduced FEV1/FVC = normal or high e.g. Oedema, infection, alveolar collapse (effusion) / destruction (fibrosing alveolitis) / abdominal distension / neuromuscular disease (Duchenne, Guillain Barre) / congenital malformation (kyphoscoliosis) Obstructive pattern Reduced FEV1 compared to FVC FEV1/FVC = low (approx. 40%) e.g. asthma Mixed picture Decreased FVC but more decreased FEV1 = Mixed picture e.g. CF Peak Flow PEFR = cheap & easily available. Am always worse than Pm (normal diurnal variation = shark tooth pattern) Oxygen Dissociation Curve Shifted to right if: Raised temp Raised CO2 Raised 2,3-DPG Acidaemia = less affinity for O2 E.g. surrendering O2 at tissues Shifted to left if: Low temp Low 2,3-DPG Low CO2 Alkalosis = higher affinity for O2 E.g. fetal Hb Blood gases pH à acidosis / alkalosis CO2 à if high = resp Then look at Base excess = amount of acid you need to add to return to pH 7.4 with NORMAL CO2 & O2 Therefore +ve BE = alkalosis = need to Add Acid Compensation for primary respiratory acidosis à increase Bicarb so need to add acid Excessive loss of HCl in gastric juice by vomiting e.g. pyloric stenosis Renal overproduction of bicarbonate e.g. Cushing’s -ve BE = acidosis = Add Base Compensation for primary respiratory alkalosis Diabetic ketoacidosis = keto acids Lactic acidosis Chronic renal failure - preventing excretion of acid and resorption and production of bicarbonate Diarrhoea – excretion of bicarb Ingestion of poisons such as methanol, ethylene glycol, or excessive aspirin Malformations • Congenital over distension of a lobe = aka congenital lobar emphysema o Usually occurs due to malformation à ball valve effect o à compresses rest of normal lung tissue + mediastinal shift à surgical removal o M:F = 3:1 o Most commonly LU lobe (42%), then RU (35%), then RM (21%) o Cause only found in 50% of cases – can be due to internal factors (defective cartilage, mucosal folds, mucous plugging) or external compression due to vascular rings, LN, tumour etc. o 20% assoc. with other congenital anomalies – e.g. PDA, VSD, rib anomalies o 33% present at birth, further 50% by 1 month o Sx – respiratory distress, cyanosis, feeding problems o Ix: § CXR – large lucent area with mediastinal shift and contralateral collapse § CT scan – may show obstruction source § VQ scan – increased perfusion of unaffected, decreased perfusion of affected lobe (splinting of vessels) o Treatment - lobectomy • Sequestration o Part of the lung develops without connections to vessels / bronchioles. o Can have own pleural lining o Usually in left lower, others R lower lobe o Present as cystic pneumonia / incidental o = mass on CXR • Bronchogenic cysts o Usually on right near midline structure but can be lower lobe o Fever, chest pain & productive cough o May contain air / fluid level • Simple cysts = uncommon • Congenital cystic adenomatoid malformations (CCAM) o abnormal differentiation à can have abnormal vascular / cystic elements o can present in newborn / small infants with distress, recurrent infection & pneumothorax • • • Stridor o Can à high output failure & respiratory distress o Diagnosed antenatally / early postnatal period – Cyst / Occasionally air fluid level on CXR o Risk of infection & malignancy therefore should be removed Malformation of the conducting airways o bronchial atresia à abnormal distal lung requiring lobectomy o tracheal and bronchial stenosis – can be isolated / vascular ring / T-O fistula § Limited outcomes as will fail to develop that section of lung Chest wall o Pectus carinatum (pigeon chest) – assoc. with increased effort à resp failure § e.g. Marfan’s, Noonan’s, hyperphosphataemia o Pectus excavatum = restrictive deficit & cosmetic defect § E.g. severe rickets, CDH repair, Marfan’s, Homocysterinuria o Surgery has high morbidity & limited effects on improving lung function Upper airway anomalies o Cleft lip & palate o Pierre-robin o Choanal atresia FIRST EXCLUDE EPIGOLTITIS Congenital – inspiratory due to laryngomalacia (floppy larynx) Ix to exclude vascular ring compressing trachea Expiratory – harsh noise, due to tracheo/bronchomalacia, B2agonist no effect Repair any tracheo-oesophageal fistula found NB: distinguish from stertor (nasal breathing in babies with URTI) Causes Croup Bacterial tracheitis Sub-glottic stenosis Foreign body aspiration Retropharyngeal abscess Smoke inhalation Diphtheria Angio-neurotic oedema ACUTE Croup – aka laryngotracheobronchitis. 6m-5yrs Peaks in autumn and spring Inflammation of upper airways à laryngeal narrowing Typical symptoms are inspiratory stridor, barking cough and hoarse voice Symptoms start with coryza (1-2 days) then cough starts at night Mild = active well child with barking cough, stridor with agitation, minimal increased work of breathing Rx - no treatment needed Mod = stridor at rest, some increased work of breathing. Rx Oral dex / neb budesonide Severe = stridor at rest & expiratory component, increased WoB, resp distress, raised RR & HR. When become quiet = decompensation. Rx O2, neb adrenalin fb steroid, may need intubation & ventilation Causes Viral - 75% are parainfluenzae – rest RSV, influenza, metapneumovirus or adenovirus rhinovirus & measles Bacteria – Mycoplasma, HiB, S.Pyogenes, S.Aureus, Moxarella Generally resolve in 3/7 <5% need admission Stridor None Agitation Rest Recession None Mild Mod Severe Air entry Normal Decreased V. Decreased Cyanosis (Air) None Agitation Rest Level of Conc Normal Disorientated <4 = mild 5-6 = mild – mod 7-8 = mod 9< = severe 0 1 2 0 1 2 3 0 1 2 0 4 5 0 5 NB: Acute spasmodic croup = no preceeding coryza, afebrile, otherwise similar profile to above. Strong atopic FH/BG Rx: only in serious cases, O2 support, steroids (1-2mg/kg) ? intubation. Should settle over 2-3 days Epiglottitis – 1-7 yrs. Fever, toxic drooling, emergency Onset 4-6 hrs Quiet muffled stridor with pooling of saliva & cherry red epiglottis Mostly caused by HiB Rx: keep patient calm, DO NOT EXAMINE THROAT, get anaesthetist & URGENT INTUBATION then à blood tests (usually HiB), give cefotaxime & hydrocortisone Bacterial Tracheitis 6m-8y, Uncommon BUT Now more common than epiglottitis due to HiB vaccine Toxic child, Purulent secretions & mucosal necrosis Croupy cough & toxic/febrile/ill Usually S.Aureus Intubate & give Abx Anaphylaxis Inhaled foreign body CHRONIC Laryngomalacia Noted in first few weeks Collapse of supraglottic structures Starts at approx. 2/52, increased to peak 2-6m, then improves with age (resolved by 2y) Increased noise with activity, lying supine & illness Confirm Dx with flexible laryngoscopy Can be assoc with GORD If progressive need to exclude expanding haematoma Subglottic stenosis Acquired more common than congenital Usually follows prolonged intubation Haemangioma Tend to be subglottic Enlarge in 1st few months, then resolve over several yrs – can treat with propranolol Vocal cord paralysis Bilateral recurrent laryngeal nerve palsy à severe stridor e.g. due to surgery, spina bifida or Arnold chiarii malformation Vascular compression e.g. double aortic arch / vascular ring Recurrent Cough In a previously healthy child Infection – pertussis, chlamydia, mycoplasma Cough variant Asthma Post nasal drip (rhinitis) GORD Psychogenic (habitual) cough Smoker (including passive smoking) FB – sudden onset, can à chronic Sx In a child with FTT / other illnesses Aspiration – videofluroscopy / 24 hr pH study CF – do sweat test & genotype Primary Ciliary dyskinesia – saccharine test / electron microscopy of brushings Immune deficiency – test IgG & subclasses + response to vaccines (function Abs) UPPER AIRWAY PROBLEMS Otitis Media Commonly Haemophilus / streptococcus S&S: Usually febrile, young children cannot localise pain O/E: Bulging tympanic membrane with loss of light reflex Complications: Infection can spread to mastoiditis / meningitis or à secretory otitis media = glue ear can à perf drum Rx: myringotomy & grommets otherwiseà conductive deafness. Removal of adenoids may help Rx – Abx sparingly Tonsillitis Usually viral / strep S&S: Poor fluid intake, discomfort with swallowing, fever, halitosis O/E: enlarged inflamed tonsils & LN (viral in preschool, bacterial in school) EBV à “florid” with petechial haemorrhages on palate Ix: ALL children should have throat swab for culture + monospot test if >3 days / markedly enlarged LN Rx: paracetamol, encourage fluid intake, Abx based on swab results Tonsillectomy only if > 5 episodes / yr AND / OR significant effect on breathing etc Complications - If severe à peri-tonsillar abscess Rhinitis Especially common in preschool children Usually viral / atopic. Local – nasal polyps, chronic sinusitis, chronic infected adenoids, deviated septum, foreign body, nasal diphtheria Generalised – CF, dysmotile cilia syndromes, allergy, syphilis, Wegner’s Granulomatosis, immune deficiency, hypothyroid Decongestants are of little help, antihistamines will improve if atopic Epistaxis Picking à damage Bleeding most common from little’s area Can à mistaken for haemoptysis (coughing up of swallowed blood) Inhaled foreign body Expect from 6 months old, may present late with haemoptysis 42% in R. main bronchus 17% in larynx / trachea S&S: dyspnoea, wheeze, stridor Ix - CXR (unilateral hyperinflation, collapse on expiratory film) Lung Cysts Congenital – see above Lobar emphysema, CCAM, Bronchogenic Cyst, Sequestration Acquired Bronchiectasis CF TB Post measles / pertussis Infection – staphylococci, klebsiella RESPIRATORY INFECTIONS 50% of illness in pre school children 30% of illness in school age children Pneumonia Community Acquired Pneumonia Most common in <5yrs (35-40/1000 in under 5yrs, 15-20/1000 in 5-12y) 1/3 viral Up to 40% mixed (virus + bacteria) If bacterial then usually strep pneumonia, mycoplasma or Haemophilus Can also be Chlamydia, pertussis, staph aureus or TB Risk factors More common in boys Prematurity Immune problems Cystic Fibrosis Neuromuscular / cardiac problems Previous respiratory infections / wheeze Malnutrition Socio-economic factors – overcrowding, poor housing, parental smoking, non immunisation Causes: Mostly viral = bronchopneumonia 10-30% bacterial = lobar Bact GBS, S.Aureus, S.Epi, E.coli Neonate 1-4m <5yrs S.Aureus, HiB, S.Pneumonia S.Pneumonia, S.Aureus, HiB, Grp A Strep S.Pneumonia, HiB >5yrs Imm. Compromised CF S&S: Ix: PCP, enteric Gram -ves Virus RSV, Herpes, Enterovirus RSV, Flu/paraflu, CMV RSV, Flu, adenovirus Others Myco/ureaplasma Flu Mycoplasma, chlamydia, legionella Fungi, aspergillus, histoplasma Aspergillus CMV, RSV, Flu/Paraflu S.Aureus, Cepacia, Pseudomonas, maltophilia If staph à very sick with rash, headache, GI sx etc Chlamydia, ureaplasma Triad of: Temp > 38.5 Recession Raised RR (>60 is <2m, >50 if 2-12m, >40 if over 12m) Others include SOB (usually in older children) Wheeze = more likely viral infection & other signs of resp distress, poor feeding etc Record O2 sats (give O2 if <93%) CXR ONLY if <5 years with fever without focus / bilateral signs on examination / history of choking Blood cultures in all admitted cases Nasopharyngeal aspirate if < 18m old If empyema à drain & send for micro CRP is USELESS!!! U&E if clinical concerns over dehydration CXR indications <5yr PUO Complication suspected (effusion etc) Atypical symptoms/ no response to treatment FOLLOW-UP only for lobar collapse / round area (? Loculated) / on-going symptoms Admission: Sats < 92% in Air RR > 70 in infant, >50 in child Cyanosis Apnoeas Difficulty breathing Grunting Decreased oral intake / dehydration Family unable to supervise closely at home Rx: O2 to maintain sats above 92% Antipyretic Analgesic Antibiotics 1st line = Amoxicillin Can use macrolide if allergic / ? mycoplasma / >5yrs If ? Staph then use fluclox IVI if dehydrated at no more than 80% maintainence Minimum 4 hrly obs Complications: Low sodium due to SiADH Empyema / effusion / abscess – usually pneumococcal pneumonia Metastatic infection – osteomyelitis / septic arthritis If … Unresolving infection à ? antibiotic resistant / TB Recurrent infection / atelectasis in same areas à ? congenital malformation / foreign body / aspiration Recurrent infection / atelectasis in different area à CF / Immune suppression / Aspiration If 2 confirmed episodes of LRTI then ?? Genetic – CF, sickle Immune – Bruntons agammaglobulinaemia, IgG subclass deficiency, SCID, AIDS Leucocyte disorders – chronic granulomatous disease, hyper IgE Syndrome, Leucocyte adhesion defect Ciliary disorders – immotile cilia syndrome, Kartageners Anatomical – sequestration, bronchial cysts, lobar emphysema, reflux, recurrent aspiration, TOF, bronchiectasis Measles (see more in infection notes) Can à croup, otitis media, bronchopneumonia, Vit A improves outcome Pertussis Path Bordetella pertussis / parapertussis Gram –ve organism – invades epithelium and causes damage by toxins Higher incidence in summer Highly infectious by droplet spread Incubation 6-21days (usually 7-10d) ALWAYS consider if cough > 2 weeks Risk factors - under 2 months (= before vaccine), not immunised Transmission – can be from “silent” asymptomatic case. Remain infectious for 6 weeks post cough onset Symptoms – coughing, later evolving to paroxysms (7-14d) with whooping +/- vomiting Cough continues for up to 100d Fever usually absent / mild Can à petechiae / sub-conjunctival haemorrhages Can à apnoeas / cyanosis / seizures (anoxic) Diagnosis – cough > 2/52 + paroxysms + no other evident cause Differentials – parapertussus (not covered by vaccine), asthma, bronchiolitis, sinusitis, COPD, CF, inhaled FB, pneumonia, (esp atypical) TB, viral URTI, reflux, post nasal drip, ACEi therapy Investigations Culture from NPA = difficult – best if processed fresh, before Abx and early in disease PCR – less affected by antibiotics Serology – more use after 3-4 weeks, Single raised IgG = highly sensitive and specific, not as easy to interpret if recent immunisation WBC – mild leucocytosis + upto 70% lymphocytosis CXR – non specific Complications Pneumonia = 6% Serious = dehydration, apnoea, hypoxia, encephalopathy, brain haemorrhage – usually in < 1 yr & not immunised Milder = sinusitis, OM, viral / bacterial added infection, FTT due to vomiting, seizures, rectal prolapse, urinary incontinence, hernia, back pain, rib # Treatment Antibiotics – macrolide is 1st choice. <1m = azithromycin, >1m = clarithro/erthryo/azithro. Can also use cotrimoxazole. DON’T alter disease course but reduce infectivity Isolate Post exposure prophylaxis for contacts Vaccine – can à temp, irritable, tenderness / swelling at site. Rarely à fits, hypotonic episodes, persistent > 3hrs crying Bronchiolitis Pathology Acute viral infection of airways <1mm Leading to inflammation & epithelial cell death à Increased mucous production + bronchospasm Self limiting 3-7 days Up-to 75% will then develop post bronchiolitic cough+wheeze. These children have increased risk of asthma (? Cause,? Effect) Causes – 75% RSV, others are Flu, paraflu, adeno, rhino, and human metapneumonvirus Target ppn – 70% of RSV infections occur under 1 yr (peak 3-6m) à 20% get symptomatic disease with even fewer admitted (30/1000) Risk factors - <3m old, prem, CLD, CHD, neuro/neuromuscular disease, immune deficiency, parental smoking (breast feeding is protective) Mortality – 8.4/100,000 – increased risk if LBW, older siblings, low apgar @ 5mins, young / single mother Presentation – fever, 2-3d preceeding coryza, dry wheezy cough with fine inspiratory creps RARELY causes high fever / toxic appearance therefore always investigated further if present Differentials Resp – athma, pneumonia, inhaled foreign body, CF, congenital lung disease Non Resp – sepsis, CHD, Severe metabolic alkalosis (pyloric stenosis) Diagnosis Clinical features NPA for all <18/12 = doesn’t alter management – but does allow infection control CXR – NOT needed – but may show hyperinflation, diaphragmatic flattening, patchy atelectasis, collapse / consolidation in 1/3 children (esp upper lobes) Severe disease = needs admission RR> 70 or apnoeas Signs of respiratory distress O2 sats < 94% / cyanosis Fluid intake < 50% usual Lethargy Treatment Supportive O2 – headbox / prongs Feeds (NG / IVI) Blood gases only if deteriorating Nasal suction may lead to decreased distress Physio – ONLY in PICU NO EVIDENCE FOR BRONCHODILATORS Palivisumab = prevention of RSV only Complications Apnoeas – 10% of admitted, 20% of PICU Bronchiolitis obliterans – only if adenovirus Encephalopathy Hyponatraemia (SiADH) Pneumocystis Obligate extracellular parasite with attributes of fungi & protozoa Most humans are sero+ve by 4yrs old 40% of HIV & 10% of ALL will get PCP without prophylaxis Defence is cell mediated, therefore can also occur in SCID Infection almost always affects the lungs à CXR shows alveolitis (looks like CLD). Starts at hilum & spreads peripherally. Tends to spare apex 2 forms: Epidemic infantile – 3-6 months, sublet onset, raised RR & effort with cyanosis Sporadic – can occur in children or adults with immune deficiency. Abrupt fever, raised RR, dyspnoea, cough & cyanosis Diagnose by Broncho-alveolar lavage or Brushings Rx with Septrin & Steroids Complications – predisposes to pneumothorax Wheeze - Differentials Bronchiolitis / post bronchiolitis Asthma / viral wheeze BPD Recurrent aspiration Congenital bronchial stenosis Tracheobronchomalacia Inhaled FB CF/ 1o cilliary dyskinesia/immune deficiency Asthma Reversible episodes of small airways obstruction à intermittent wheeze / cough Smooth muscle spasm in bronchial wall with mucosal inflammation & oedema 15% of school age children – most common in boys <5yrs Asthma Patterns Episodic viral wheeze – always with URTI, no interval Sx, poor response to asthma treatments. Variable evidence relating to steroid use. ONLY if being considered for hospital admission / previous episodes of wheeze / atopic FH Classic Atopic - +ve FH with on-going Sx when well & respond well to treatment Cough variant Asthma – nocturnal / exercise induced cough with little / no wheeze and good response to treatment Severity Infrequent Episodic = 75% – no chronic SX Episodic cough + wheeze with URTI / allergen exposure < 4 episodes per year Treat with PRN salbutamol Frequent episodic – 20% Mild chronic cough, no exercise limitation, episodic cough, wheeze & SOB 2-4 episodes per week Low dose preventer + PRN salbutamol Moderate persistent – 5% Chronic cough, esp. at night, restricted activity, frequent attacks High dose preventer + PRN salbutamol (+/- long acting bronchodilator +/montelukast) Severe persistent – troublesome cough & wheeze, exercise impairment, frequent disabling attacks Diagnosis Cough/wheeze/SOB AND absence of features of other differentials (e.g. wt loss, clubbing etc). Responding to bronchodilators. Dry cough worse at night & after exercise. Often +ve FH Hx: check atopy FH, variation during the day, peak flow diary, time off school, Triggers: exercise, emotion, allergens, virus Rx ladder: MOST effective NON PHARMACOLOGICAL method is to stop parents smoking 5-12 years 1. Mild intermittent Asthma - Occasional Salbutamol 2. Regular Preventer – 2-400microg/day (beclomethasone) 3. Add on therapy a. Long acting B2 b. If benefit but not enough à increased steroid to 400mcg c. If no response to longB2 then stop it but keep increased steroid BUT try LTRA (montelukast) OR slow release theophylline 4. Persistent Poor Control – increase inhaled steroid to up to 800mcg/d 5. Continuous / frequent oral steroids AND refer to respiratory paediatrician a. REFER sooner if concerns over failure to thrive, diagnostic uncertainty, symptoms from birth, unusual FH etc. Under 5 years 1. Mild intermittent – short acting B2 (salbutamol) 2. Regular preventer – inhaled steroid (2-400mcg) or LTRA 3. If not using – add LTRA 4. Refer to respiratory paediatrician Inhaler choices Infants (0-2y) – aerochamber Preschool (2-6y) – volumatic spacer School age (7+) – breath activated CHECK TECHNIQUE & COMPLIANCE BEFORE INCREASING ANY MEDS NB: Side effects Salbutamol / Salmeterol – tachycardia, hyperactivity and in high doses can cause hypokalaemia. NB can have paradoxical response to salbutamol / salmeterol à bronchoconstriction Inhaled steroids – sore mouth, thrush, decreased growth velocity if systemic absorption Theophylline – arrhythmias, convulsions, gastric irritation, headaches, tremor Montelukast – GI disturbance, thirst, skin reactions, sleep disturbance Common reasons for failure – poor inhaler technique, poor understanding, poor adherence, new allergens, psychological, true drug resistance is very rare Side effects of RX Inhaled steroids à oral thrust & decreased growth velocity. High dose à Cushing’s & growth delay Starting salmeterol can lead to temporary worsening of symptoms Prognosis – many children have transient disease but can recur as adult – more likely to grow out of asthma if first episodes at < 2 years & mild symptoms Acute Attack: Acute Severe Unable to speak sentences / feed <5yrs with HR > 130 or RR > 50 >5yrs with HR > 120 or RR > 30 Life Threatening if: Silent chest Cyanosis Poor respiratory effort Hypotension Exhaustion Confusion Coma ABC + O2 (aim to keep sats above 94%) Salbutamol (8-10 doses via spacer) Add ipratropium neb (can be given every 20-30 minutes for first few hours After x 3 “back-to-back” salbutamol then consider IV salbutamol bolus IV salbutamol should be 200mcg/ml OR less concentrated Then consider aminophylline in HDU setting (load with 3-5mg/kg if not already on theophylline) then 1mg/kg/hr. Consider IV MgSO4 – smooth muscle relaxant due to inhibition of calcium uptake May require ventilator support if rising Co2 levels Prednisolone (1-2mg/kg over 3-5 days) Cystic Fibrosis AR 1/2500 births (carrier = 1/25) (1/17000 African Americans, 1/90000 Indians) DF508 on Chr7 is most common mutation (70%). Survival advantage of increased tolerance to diarrhoea illness 90% of morbidity is due to pulmonary sepsis c-AMP regulated chloride channel = CF transmembrane-spanning protein is dysfunctional (failure of Cl- from cell to lumen) à low water on epithelial surface à thick mucus à mucocilliary escalator is dysfunctional à chronic infection Low Cl- à inactivates defensins & “innocent bystander” damage to lungs Also affects biliary tree, pancreas, reproductive system Testing: Can do CVS / Amnio if previous affected children Sweat Test – can be false +ve in Guthrie card at 5 days old (detects increased immune Endocrine reactive trypsin = pancreatic damage due to Untreated adrenal insuff secretions) Hereditary nephrogenic DI If +ve à genetic screen for common CF mutations Hypothyroid Sweat test (+ve in 90%) Hypoparathyroid (can be done from 6 weeks old) Metabolic Apply pilocarpine G6PD 3mA current carries pilocarpine into skin Mucopolysaccharidosis Arm washed with distilled water Fucidosis Then collect sweat on gauze / filter paper for Others 30-60 mins Ectodermal dysplasia At least 50mg required (ideally 100) Familial cholestasis Diagnostic if >60mmol of Chloride (& Cl>Na) Pancreatitis Na > 60mmol/l = +ve Malnutrition 40-60 = borderline Can be false –ve in nephrotic syndrome <40 = -ve Presentation: Meconium ileus (10-15%) – abdominal distension, bilious vomiting. Due to sludging in distal ileum. AXR shows intraluminal ground glass appearance FTT – malabsorption (pancreatic prob) à pale greasy stools, rectal prolapse (20%) Resp Problems – wheeze, productive cough, recurrent chest infections Hyponatraemia hypochloraemic dehydration = pseudobarrter’s Syndrome Others – prolonged jaundice, arthropathy, male infertility, nasal polyps and sinus probs, CF DM (3b), stress incontinence secondary to cough. Can get reflux due to lung hyper expansion à increased thoracic pressure Clinical features Bronchiectasis and emphysematous cysts Colonisation – progressive with age H.Influ – starts as toddlers S.Aureus – decreased prevalence after teen years P.Aeriginosa – dominant pathogen by 10 yrs Burkholderia Cepacia - <5% in adult ppn but significantly worsens prognosis ALSO: candida / aspergillus à allergical bronchopulmonary aspergillosis Airway hyperreactivity – in up to 25% - treat as asthma Allergic Bronchopulmonary aspergillosis Acute / subacute clinical deterioration not explained by other causes + serum IgE > 1000 + +ve skin test to aspergillus / raised specific IgE + precipitins IgG Ab to aspergillus OR new / recent CXR changes not responding to Abx Rx: high dose prednisolone & itraconazole Haemoptysis – if advanced disease / severe exacerbation due to enlarged tortuous bronchial arteries à damage Pneumothorax – emphysematous cyst rupturing into the pleural space – Rx dependent on size Sinusitis / polyps Pancreatic disease 85% will need enzyme replacement Any patients can develop pancreatitis (although more common if not insufficient) Malabsorbtion of fat soluble vitamins Raised faecal fat / elastase CF related diabetes – 12-34% Often insidious onset Rx with insulin BUT need to keep with high energy diet Annual GTT every year after 10 years old Meconium Ileus – newborn with intestinal obstruction. AXR with dilated loops and ground glass appearance. Rx with hypertonic contrast Distal intestinal obstruction (partial / complete) occurs in 5-10% due to inspissated faeces, usually >10yrs. Rx with laxatives Rectal prolapse – treated with pancreatic supplements Reflux – Rx with H2 receptor blocker / PPI CF liver disease – 5-10% = includes raised enzymes, stones, cholestasis, focal biliary cirrhosis, portal hypertension Infertility in males – obliterated vas deferens but normal sperm counts Subfertility in females – dehydrated cervical mucus CF bone disease – decreased bone mineral density (DEXA) secondary to malnutrition / vitamin D deficiency / steroid use. Rx with Vit D, Calcium supplements and bisphosphonates if required CF arthropathy – 5-10% usually 13-20yrs with transient joint pains and swelling. Usually non erosive. Can also have cipro induced arthropathy. Rx with NSAIDS Malignancy – increased risk of GI malignancy Management Under 2y recommended prophylaxis is Fluclox oral Nebulised colomycin & antipseudomonal Abx are for colonised pseudomonal patients Pancreatic enzyme supplements for all patients + physio Pneumovax = vaccine for children 2y + Acute pulmonary exacerbations Increased cough, sputum, SOB, fever, wt loss, worsening pulmonary function tests, acute CXR changes, acute changes on examination (e.g. new creps) Prophylactic Abx (colistin, ciprofloxacin for S.aureus & pseudomonas) IV Abx for infective exacerbations (via long line / portacath) based on latest sputum Physiotherapy Percussion with postural drainage Peak Expiratory Pressure (PEP) Mask à back pressure à splints airways and uses collateral airways to get behind mucus plugs Acapela / Bird – uses pressure waves DNAase (eg Dornase alpha – increased extracellular DNA released from inflammatory cells à binds to mucoproteins à viscous. DNAase à breaks down DNA à thins mucus in lungs) Hypertonic saline – increases fluid in mucus à decreases viscosity Lung transplant – most common cause of lung transplant in children Maintain growth Dietary supplement (require 130% energy to normal - overnight PEG feeds) Vitamin supplements (ADEK bec fat soluble) Pancreatic enzyme supplements (creon, pancrease) Ursodeoxycholic acid (bile acid to enable digestion & protect liver) Insulin (if CF related DM) Heart / Lung & Liver transplants may be required à reduction in energy requirements Primary Cilliary Dyskinesia Absent / dyskinetic cilia à poor mucous clearance 50% have situs invertus / dextrocardia Mostly AR inheritance Kartagener Syndrome = situs invertus, infertility + immobile cilia Old test = Assess function by time taken for granule of saccharin placed in nares to be tasted New test = high res video of beating cilia There are genetic tests but not yet for every gene involved Also have low levels of nasal NO Bronchiectasis Irreversible abnormal dilatation of bronchial tree Sx: Cough with purulent sputum, poor growth, creps & wheeze, clubbing, dyspnoea, hypoxia Ix: Lung function shows obstructive/restrictive/mixed pattern CXR with bronchial wall thickening (tramlines & rings) à high res CT Causes: Consequence of CF + recurrent infection, foreign body aspiration, immune deficiency/ cilliary probs, Can occur post RSV infection Rx: aggressive chest physio, ABX & flu vaccines. Transplant / surgery if very severe Pulmonary eosinophilia Loeffler Syndrome Widespread pulmonary infiltrations, may resemble military TB Eosinophils upto 70% of WCC Paroxysmal cough, breathlessness, pleurisy, little / no fever, hepatosplenomegaly Can be due to drugs (e.g. antibiotics / crack cocaine) or helminths (toxocara, ascariasis or strongyloides) Other causes Asthma Filariasis Chronic eosinophilic pneumonia Vasculitis – e.g. eosinophilic pneumonia with polyarteritis Idiopathic primary pulmonary haemosiderosis F:M = 2:1 Usually diagnosed at 3-10 yrs Blood loss into alveoli à Cough, haemoptysis, dyspnoea, wheeze & cyanosis Febrile during attacks Clubbing is common Fe deficient due to blood loss Biopsy shows macrophages containing haemosiderin Absence of complement on BM excludes Goodpastures Death due to chronic resp failure OR sudden severe haemorrhage Goodpastures disease (anti glomerular basement membrane disease) Glomerular nephritis + lung haemorrhage Autoimmune process (type II hypersensitivity reaction) Idiopathic diffuse interstitial fibrosis of lung (HAMMAN-RICH) Uncontrolled inflammation à fibrosis Gradual onset of sx – 2-3 weeks of early before rapid progression through late Early Sx – anorexia, wt loss & fatigue Later Sx – cyanosis, clubbing, cor pulmonale, right heart failure O/E – inspiratory crackles, decreased Vital capacity, compliance and diffusion, Restrictive deficit Rx – try steroids by mainly supportive Klippel-Feil Syndrome Failure of segmentation of C-spine vertebrae à short neck, low hairline and restricted mobility Also assoc with: Congenital scoliosis Renal Anomaly CHD Congenital anomaly of Scapula (Sprengel Deformity) Hearing Impairment Obliterative Bronchiolitis Adenovirus (serotypes 7 & 21) Parainfluenza Measles Mycoplasma pneumonia Also RSV Affected tissue doesn’t grow as well as surrounding à hyperlucencys on XR / CT Scimitar Syndrome - Aka pulmonary venolobar syndrome Congenital heart defect à anomalous venous return from the right lung to IVC Cuvilinear pattern on CXR by pulmonary veins Obstructive sleep apnoea hypopnoea syndrome (OSAHS) 10% of young children snore 1-2% of preschool age children have OSAHS Peak incidence is 2-5 years due to physiological lymphoid hyperplasia Pre puberty g=b, post puberty b>g Causes – combination of: Airway narrowing e.g. tonsils & adenoids, Obesity Neuromusclar Genetics & Hormones (+ve FH) Risk Factors Craniofacial problems (small jaw) Downs (1/2 of downs have OSAHS) – large tongue, small jaw Cerebral Palsy Prader Willi Consequences Polycythaemia Neurocognitive disruption – tend to be hyperactive Decreased IQ Recurrent LRTI (hypoventilation à collapse) Growth delay Seizures Enuresis Pulmonary & Systemic HTN inc cor pulmonale (if prolonged O2) Outcome is poor sleep quality with tiredness in day & poor school behaviour Diagnosis History & suspicion – sleeping in odd positions, snoring, mouth breathing, enuresis, etc Cycle of loud Snoring à periods of complete obstruction = stop breathing à arousal due to dropping PO2 & rising PCO2 à breathing restarts NB: apnoea, cyanosis, drooling, sweating & daytime sleepiness are all unreliable sx Confirm with video telemetry + pulse ox (most severe in REM sleep) NB: normal oximetry alone doesn’t exclude it Rx tonsillectomy (will cure most non obese children) Wt loss if obese Nasal steroids Monteleukast Nasopharyngeal tube Some will need overnight BiPAP, Ondine’s Curse (Congenital Central Hypoventilation Syndrome) Ondine = water nymph with unfaithful mortal lover. Lover swore that “every waking breath would be a testimony of his love”. On discovering adultery she cursed him to forget to breathe when asleep 1 in 200,000, Usually congenital – can occur due to trauma to brainstem Failure of autonomic control of breathing (impaired response to high Co2 & low O2)à apnoea during sleep Assoc with neuroblastoma, hirschprung’s & dysphagia Usually presents in first months of life Rx options are night ventilation or phrenic nerve pacing Pulmonary Haemorrhage & Glomerulonephritis Causes include: Goodpastures SLE HSP Polyarteritis nodosa Wegners Granulomatosis