Resp Flashcards
Signs of respiratory distress in children (7)
- Tachypnoeic for age
- Using accessory muscle
- Intercostal recession, sternal recession, tracheal tug, subcostal recession
- Head bobbing
- Nasal flaring
- Pursed lips
- Grunting
What is neonatal RDS?
Neonatal Respiratory Distress Syndrome
• Immature lungs due to prematurity
• Surfactant deficiency (decreased innate immune response, airway collapse)
• Incidence & severity inversely proportional with gestational age of infant
• Bell shaped thorax on x-ray
Risk factors for neonatal RDS
- Prematurity (!)
- Maternal diabetes
- Caesarean delivery
- Asphyxia
Treatment of neonatal RDS
- Antenatal steroid administration (enhances pulmonary maturity)
- Surfactant administration
- Appropriate resuscitation (placental transfusion, CPAP for alveolar recruitment)
- Supportive fluids, electrolyte management, nutrition
- Prophylactic FLUCONAZOLE
Complications of neonatal RDS
- Septicaemia
- Bronchopulmonary dysplasia
- Patent ductus arteriosus
- Pulmonary haemorrhage
- Apnoea, bradycardia (ABC)
What is neonatal chronic lung disease also called?
Bronchopulmonary dysplasia
Definition of chronic lung disease?
= Prolonged need for ventilatory support beyond 36 weeks post conceptual age
=Prolonged need to O2 beyond 28 days with abnormal CXR
What is the pathophysiology of neonatal chronic lung disease?
- Airway epithelial necrosis
- Squamous metaplasia
- Organisation of hyaline membranes
- “white out” lung fibrosis
- Fewer and larger alveoli (emphysematous change)
Risk factors for neonatal chronic lung disease?
- Gestational age
- Low birth weight
- Male gender
- Need for resus after birth
- Ventilation
- O2 toxicity
- RDS
- Infection
- ILD (interstitial lung disease)
- Pulmonary hypertension
- Cystic fibrosis
- Neuromuscular disease
Complications of neonatal chronic lung disease?
- Persistent O2 & ventilation requirements
- Increased hospital stay/need for home O2
- Pulmonary hypertension
Xray findings of neonatal chronic lung disease?
- Indistinguishable from RDS
- Marked radio opacity of lungs
- Cystic/bubbly pattern of opacity
- Hyperexpansion, linear streaks & emphysema +/- cardiomegaly
What can be done to prevent neonatal chronic lung disease?
- Antenatal steroids when preterm birth is anticipated
- Avoid excessive O2 & ventilation
- Give surfactant early
- Optimise ventilation
Treatment of neonatal chronic lung disease
- Post natal steroids (low dose, DART, avoid in 1st week of life unless life threatening
- Nitric oxide?
- O2
- Avoid fluid overload +/- diuretics
- Use pressure ventilation rather than volume
- Vitamin A
What is asthma?
Chronic inflammatory obstructive airway disease characterised by reversible airway obstruction
What causes asthma?
- Bronchial muscle contraction (triggered by cold air, smoking, allergies, B-blockers, NSAIDs, infection)
- Mucosal swelling & inflammation (mast cells and basophils releasing inflammatory mediators)
- Increased mucus production
Symptoms and signs of asthma
- Dyspnoea and chest tightness (decreased FEV1/FVC ratio)
- Wheeze
- Cough (often night/early morning)
- Sputum
- Tachypnoea
- Audible wheeze and polyphonic wheeze
- Hyperinflated chest (hyper-resonant percussion)
- Widespread reduced air entry noises
What happens during an acute attack of asthma?
- Unable to complete sentences
- Pulse >110bpm
- Resp rate>25/min w/accessory muscle use
- Peak expiratory flow 35-50% predicted
What would indicate life threatening asthma?
Bradycardia, no air entry, cyanosis, confusion!!
Treatment of acute severe asthma
- O2
- Nebulised B2 agonist (salbutamol)
- Oral prednisolone/IV hydrocortisone
- Add Ipratropium (atrovent) and magnesium if no improvement
Name 3 types of relievers for asthma and an example of each
ß2 agonists: salbutamol
Methylxanthines: aminophylline
Antimuscarinics: ipratropium
Name 5 types of preventers in asthma and an example of each
Corticosteroids: beclametasone Cromones: sodium cromoglycate Anti-leukotrienes: montelukast PDE4 inhibitors: roflumilast MgSO4
How do salmeterol and formoterol gain their long lasting effects?
SALMETEROL - flexible tail
FORMOTEROL- dissolves in plasma membrane
Action of ß2 agonists
Acts on ß2 adrenoreceptors
Inhibits mediator release from mast cells and monocytes
Broncodilates
SE of ß2 agonists
Tachycardia, tremor, lactic acidosis
Hypokalaemia, hyperglycaemia
Action of methylxanthines
Asthma reliever
• Hyperpolarises muscle cells -> bronchodilation
• Increased cilia action
• Decreased muscle fatigue in chest and diaphragm -> improved ventilation
• Decreased histamine & leukotriene release
SE of methylxanthines
Similar to coffee
GI upset, headache, insomnia
SE of antimuscarinics
Dry mouth, constipation
Action of corticostroids in asthma
- Suppresses inflammation and immune response
- Decreased oedema and inflammatory cell activation and recruitment
- Decreased leukotrienes
SE of inhaled corticosteroids
Oral candidiasis, hoarseness
Action of cromones
Mast cell stabilisation
Decreased eosinophil activation
Decreased IgE
Name the steps involved in asthma medication
1) Inhaled SABA (salbutamol) when needed/Ipratropium if intolerant
2) Regular inhaled GCS (beclametasone)
3) Inhaled GCS + inhaled LABA (salmeterol)
4) High dose inhaled GCS + anti-leukotriene (montelukast) + oral theophylline +/- LABA
5) Oral GCS
What is bronchiolitis
An acute inflammatory injury of the bronchioles that is usually caused by a viral infection
Affects those less than 2 (tiny airways)
Peak age 3-6 months
Causes of bronchioloitis
RSV, flu, paraflu, rhinovirus, adenovirus (highly infectious)
Pathophysiology of bronchiolitis
- Lower respiratory tract viral infection
- Increased mucus secretion
- Bronchial obstruction and constriction
- Alveolar cell death, mucus debris, viral invasion
- Air trapping
- Atelectasis
- Reduced ventilation that leads to ventilation-perfusion mismatch
- Laboured breathing
Name 11 risk factors for bronchiolitis
- Age less than 3 months
- Low birth weight
- Gestational age (esp <29weeks)
- Lower socioeconomic
- Crowded living conditions, childcare centre attendance, presence of an older sibling or a combination
- Parental smoking
- Chronic lung disease
- Severe congenital or acquired neurologic disease
- Haemodynamically significant congenital heart disease (CHD) with pulmonary hypertension
- Congenital or acquired immune deficiency diseases
- Airway anomalies
Signs of bronciolitis
- Tachypnea
- Tachycardia
- Fever (38-39°C)
- Retractions
- Fine rales (47%)
- Diffuse, fine wheezing
- Otitis media
- Profuse coryza
- Fine rales, wheezes
Investigations for an infant presenting with bronchiolitis symptoms
- Viral swab
- ABG
- WCC & CRP
- CXR
- Septic screen
- Pulse oximetry (90% lower limit for hospitalisation)
7 differential diagnoses to bronchiolitis
- Bronchomalacia
- Cardiac disease/congenital heart disease
- Congenital lobar emphysema
- Congenital structural airway anomaly
- Constrictive bronchiolitis
- GORD
- Tracheal ring/vascular ring
Treatment of bronchiolits
- Bronchiolitis is an infectious, self-limited disease (7-10days)
- Supportive care (nutrition may need to be NG if tachypnoeic-> aspiration)
- Oxygenation (+/- CPAP)
- Nebulised hypertonic saline & saline drops and suctioning
- Hydration
- Fever control
- Avoidance of exposure to tobacco smoke or other irritants
- Methods for limiting transmission (eg, handwashing and avoiding childcare centres while ill)
When is a PICU admission required for bronchiolitis
- Worsening hypoxemia or hypercapnia
- Worsening respiratory distress
- Persistent oxygen desaturation and/or severe cyanosis in spite of adequate oxygen delivery
- Apnoea
- Acidosis
- Extra-pulmonary symptoms
- Worsening mental status
- Unclear aetiology of symptoms
Complications of bronchiolitis
- Acute respiratory distress syndrome (ARDS)
- Bronchiolitis obliterans
- Congestive heart failure
- Secondary infection
- Myocarditis
- Arrhythmias
- Chronic lung disease
Treatment of severe viral croup
Humidified warmed air Oxygen Intubation Steroids Nebulised adrenaline
