Allergy & Immunology Flashcards
Asthma Pathophysiology
After an episode: airways fill w/ mucus,muscles around the airway contract, airways swell
Obstruction- partially reversible w/ bronchodilator therapy
Hyperresponsiveness- abnormal response to external stimuli
Chronic inflammation
mast cell activation → inflammatory cell infiltration: eosinophils, helper T-cells lymphocytes, neutrophils
Asthma Predictive Index
Criteria utilized to predict a diagnosis of asthma for ages 3 or younger w/ 4 + wheezing episodes within the past year:
Major (need 1)
- Parent w/ asthma
- Diagnosis of eczema
- Sensitivity to aeroallergens
Minor (need 2)
- Food allergy
- >4% eosinophils in blood
- Wheezing not associated w/ URI
Asthma classification: symptoms
Intermittent: </= 2 days/week
Persistent: mild, moderate, severe
- Mild > 2 days/ week, but not daily
- Moderate- daily
- Severe- throughout the day
Asthma classification: severity
Impairment
- nighttime awakenings
- SABA use
- interference with normal activity
- lung function
Risk
-exacerbation requiring oral steroid use
Asthma classification: control
3 categories:
- Well controlled - little to no use of rescue inhaler
- Not well controlled- increasing use of rescue inhaler
- Very poorly controlled- excessively using rescue
Assessed as often as every 1-6 mts
Therapy adjustments made based on asthma classification + level of control
Asthma Diagnostic Criteria
Current episodic symptoms of airflow obstruction
- Cough, wheezing, SOB, chest tightness
Airway flow obstruction or airflow limitations that is partially reversible with bronchodilator
- Younger children with positive clinical response to bronchodilator
- Older children with evidence of improvement measured by spirometry
Alternative diagnosis excluded
Quick Relief Medications
SABA- albuterol MDI or nebulized
Oral corticosteroid- prednisone, methylprednisolone, dexamethasone
Anticholinergic- ipratropium bromide MDI or nebulized
Short acting beta agonist (SABA)
quick relief
albuterol - metered dose inhaler (MDI) or nebulized
Anticholinergic (asthma)
quick relief
ipratroprium bromide (MDI or nebulized)
Oral steroids (asthma)
quick relief
prednisone, prednisolone methylprednisolone (1-2 mg/kg/day; max 60mg/day)
dexamethasone (0.3-0.6 mg/kg/day; max 12-16 mg/day)
Long term controllers
Inhaled corticosteroid (ICS)- Budesonide, fluticasone, beclomethasone,mometasone
SABA+ICS
LABA- salmeterol, formoterol
LABA+ICD-Fluticasone+Salmeterol, Budesonide+Formoterol, Mometasone+Formoterol (dulera)
Leukotriene receptor antagnonists (LRA)- montelukast
Inhaled corticostroids (ICS)
long term controller
Budesonide, fluticasone, beclomethasone, mometasone
LABA
long term controller
salmeterol, formoterol
LABA + ICS
long term controller
Fluticasone+Salmeterol (advair, airduo)
Budesonide+Formoterol (symbicort)
Mometasone+Formoterol (dulera)
Leukotriene receptor antagonist (LRA)
long term controller
Montelukast
Asthma differentials
Allergic rhinosinusitis
Sinusitis
Adenoid or tonsillar hypertrophy
Foreign body
Vocal cord dysfunction
Tracheobronchomalacia
Cystic fibrosis
Bronchiolitis
Pneumonia
Bronchiectasis
Gastroesophageal reflux
Adverse reaction to ACE inhibitor meds
Increased risk of asthma death
History of sudden, severe exacerbation
Prior ICU admission
Prior intubation for asthma
2 or > hospitalizations or > 3 ED visits
Using >1 canister of SABA in short period of time
Chronic oral steroid use
Inability / difficulty perceiving severity of asthma
Status Asthmaticus
Severe asthma exacerbation
Risks include:
-multiple hospitalizations
-prior intubation
-prior attack with severe, unexpected & rapid deterioration
-frequent beta agonist use
-abrupt cessation of ICS
Manifestations:
coughing, wheezing, difficulty breathing, retractions, complaint of chest pain, nasal flaring, grunting, head bobbing, difficulty speaking in sentences, anxious
Signs of impending respiratory failure
Altered mental status
Cyanosis
Decreased breath sounds
Difficult to speak more than a few words in a single breath
Status asthmaticus PE/management
PE: tachycardia, tachypnea, pulsus paradoxus (decrease in SBP of >10 mmHg during inspiratory phase), hypoxemia
Observe LOC, hydration status, peripheral perfusion (check cap refill)
Management - hospitilization
Oxygen if hypoxic
IVF for rehydration
Bronchodilator therapy, anticholinergics, magnesium sulfate IV
IV corticosteroid - Methylprednisolone 2-4mg/kg/day given every 6-12 hrs (max 60 mg/day)
PICU if requires positive pressure ventilation (PPV), sedation or IV bronchodilator infusion