atopy
genetic tendency to develop an IgE response to common environmental proteins
atopy results in
wheezing
eczema
season rhinitis
triggers of asthma
URI Allergens cold exercise latex
mc chronic dz in childhood
asthma
asthma and gender
mc in boys in childhood, equals out in adolescence
boys “out grow”
characterization of asthma
- Airway obstruction (mucous)
- airway hyperactivity (bronchial spasm)
- chronic airway inflammation (edema)
fundamental issue in asthma
immunological inflammatory response
prolonged local airway inflammation and hyper-responsiveness
hypersensitivity to triggers = over production of IgE and blockage of Beta-2 receptors
normal reaction to allergens in pulmonary system
non specific still causes activation of local inflammatory cells
pathophysiology of asthma
immune system activation causes release of leukotrienes, histamine and prostaglandins
immune system activation of asthma causes:
smooth muscle contraction
mucous hyper secretion
vasodilation with endothelial leak and local edema
impairment of mucociliary elevator
smooth muscle contraction
narrows the airway lumen and limits expiratory flow
mucous hyper secretion
clogging smaller airways and narrowing airway lumen of larger bronchioles
causes cough
vasodilation with endothelial leak and local edema
decreased ability to exchange oxygen
loss of lung compliance
narrowing airway of lumen
impairment of mucociliary elevator
decreased ability to remove allergens and particulates from the lung
anatomic results of pathophysiologic process
- mucosal thickening and infiltration of airway wall with inflammatory cells
- hypertrophied and contracted airway smooth muscle
- damaged bronchiole cells, exposing nerves to stimulation
- increased number of mucus glands, hyper secretion and plugging of airways
- airway remodeling and fibrosis
hygiene hypothesis
extreme hygiene results in a weakened immune system unable to self regulate
HYPERSENSITIVITY
triggers of asthma
atopy exercise URI GERD weather tobacco pollution ASA/NSAIDS hormones, emotions
exercise induced asthma
bronchospasm following exercise in patients with underlying asthma
tx: SABA prophylactic
dx: exercise challenge test or document in pts with asthma
GERD asthma
cough secondary to GERD
susceptible to lifestyle modifications, acid reducing medications (PPI)
clinical features of asthma
wheezing cough SOB chest tightness accessory muscle use short sentences anxiety
wheezing
loudest in chest
does NOT clear with cough
coughing asthma
common presenting symptom
nocturnal, seasonal recurrence lasts >3 weeks, likely due to asthma
increased likelihood of asthma
- episodic symptoms
- personal history of atopy
- history of asthmatic symptoms
- triggers: exercise, allergen exposure, ASA, viral URI
decreased likelihood of asthma
lack of improvement following anti-asthma medications
onset of symptoms after age 50
history of prolonged cig smoking
concomitant symptoms
exam findings that support asthma diagnosis
play-bluish, swollen nasal mucosa
lichenifield plaques
nasal plus
diagnosis of asthma is based upon
clinical picture + pulmonary function testing
spirometry is diagnostic test of choice
parameters of spirometry
FVC
FEV1
FEV1/FVC ratio
peak flows
less accurate, can be done at home
need to be confirmed in office
allows us to measure progress
diagnostics used in asthma
pulse ox PEF ABG allergy test exercise challenge test
classic CXR findings in asthma
mc - normal
hyperinflation, flat diapraghm
medications to use with caution
non-selective COX inhibitors
non-selective BB
ACE I
who gets spacers?
children and elderly
benefit of nebulizer
facemaske or mouthpiece
long delivery without depending on patient use
delivers medicine deep into the lungs
bronchodilators list (6)
SABA LABA Anticholinergic mg Combined alpha and beta Methylxanthines
immunomodulators list (4)
ICS
leukotriene modifiers
mast cell stabilizers
systemic steroids
SABAs
beta 2 agonists
rescue medicines
ADRs of SBA
hypokalemia palpitations tachycardia HTN angina
LABAs
controller medications that prevent bronchospasm by relaxing bronchial smooth muscle
LONG lasting bronchodilator (>12 hrs)
SABAs drug
albuterol (proventil, ventolin, ProAir)
Pirbuterol (maxair)
Levalbuterol (Xopenex)
LABAs drug
Salmeterol (servant)
formoterol (foradil)
LABA FDA
ALWAYS used with ICS
NEVER as a mono therapy
ICS
controller medications that use local anti-inflammatory affect
high inflammatory activity with LOW systemic response
not for emergency use takes 1-2 weeks
adjusting ICS in asthma
when initiating therapy start low, go slow
ICS adr
local affects
oropharyngeal candidiasis
dysphonia
low risk systemic adverse affects
leukotriene receptor antagonist
inhibits 5-lipoxygenase (zileuton) or competitive inhibition of leukotriene (montelukast, zafirlukast)
advantages of leukotriene receptor antagonist
improve FEV1
decrease asthma symptoms
oral therapy
list of leukotriene receptor antagonist
Zilueton (Zyflo)
Montelukast (Singular)
Zarfirlukast
disadvantages of leukotriene receptor antagonist
not as effective of ICS
linked to risk of suicidal thoughts and depression
Cromolyn
mast cell stabilizer
only effective by inhalation
minimal adverse effects but not as effective as ICS
Omalizumab (Xolair)
monoclonal Ab targeting Fc of IgE
> 12 yrs old
SubQ infection, dosed 2-4 weeks, dose based on IgE
Expensive!!
systemic corticosteroids
acute exacerbation or severe uncontrolled asthma
Burst of anti-inflammatory activity (5-10 day)
IV or PO
can have ADR
consider systemic steroid if: (5)
- decreasing lung fxn over days
- lack of sustained relief from rescue medication
- repeated drops in PEF over 1 or more days to below 60%
- freq. night time symptoms
- req. for emergency nebulizer or parenteral bronchodilator tx
anticholinergics
long history of use but NOT FDA approved
reverse cholinergic mediated bronchoconstriction
ipratropium
anticholinergic
atrovent or nebulizer solution
used adjunct to SABA
how to triggers produce bronchospasm
vagal reflex mechanisms
parasympathetic-ally innervated
metylxanthines
theophylline
PDE5 inhibitor produced by bronchodilator
disadvantage of methylxanthines
little effect
small therapeutic index
many drug interactions
ADR of metylxanthines
HA, N/V, rumor, insomnia
arrhythmia, seizures, hypoK
antihistamines
adjunct OTC medications for allergy mediated asthma
no FDA asthma approval
asthma and pregnancy complication
low birth weight
increased likelihood of prematurity
neonate death
try to avoid hypoxia in both mother and deaths
DOC of pregnancy
ICS
albuterol, veclomethasone, budesonide, prednisone, theophylline are safe
perioperative pts and asthma
complications
acute bronchospasm from intubation
impaired cough
hypoxemia
atelecasis
respiratory infection
perioperative pts and asthma
management
pre-op: evaluate symptoms, med use, PFTs
oral steroid to optimize before sx
