Ex5 Asthma/COPD Flashcards
Bronchospasm is most likely to occur
at induction
Severe asthma is defined as
1 major + 2 minor criteria
Major criteria
tx w/ high-dose inhaled corticosteroids or tx w/ oral corticosteroids for 50%+ of the year
Minor Criteria
-albuterol daily
-near fatal asthma event in past
-require addtnl daily controller tx (long acting beta agonist, theophylline, omalizumab, leuk recept antag)
-persistent airway obstruction (FEV1 <80%, peak exp <20%)
- >/= 1 urgent care visit/year
>/= 3 corticosteroid bursts/year
Risk factors of mortality + asthma exacerbation
- prior episode of near fatal asthma
- in prior year: >/= 2 hospitalizations or >/=3 ED visits
- in past month: hospitalizations/ED visit for asthma or use >/=2 canisters short acting b-agonist
- social hx: major psychosocial issues, illicit rx use, low socioeconomic
- concominant illness: cv/mental/chronic lung dx
Management of asthma exacerbation
- mechanical ventilation
- Rx: B-agonist, anticholinergic, corticosteroids, mag
- NonRx: o2, heliox
First line Rx tx - asthma exacerbation
Beta agonists (rapid acting)
Beta-2 agonists cause
bronchodilation of smooth muscle
Selective Beta-Agonists
Albuterol
Levalbuterol
Terbutaline
Non-selective Beta-receptor agonists
Epinephrine
*acts on both B1/B2 receptors
Selective beta-agonists at high doses may lead to
loss of selectivity
–> tachycardia
Onset - Beta agonists
5 minutes
Repeat until bronchospasm subsides
After several hours of no response to tx with Albuterol in acute asthma exacerbation, what are next steps?
- Consider Terbutaline injection (SubQ) or Epi injection (SubQ/IM)
- c/i - arrythmia/HTN/CHF/CAD
Beta-agonist AEs
- tachyphylaxis
- hypokalemia
- hyperglycemia
- Tybe B Lactic Acidosis
Rx intxns: Beta-agonists
Other adrenergic Rx –> tachycardia
Beta blockers - some extent of antagonism
Adverse effect of anticholinergic therapy
inhibits mucus secretion
Add on to beta-agonists in asthmatics
anticholinergics (ipratropium)
Role of corticosteroids in asthma exacerbation
Onset: 6-8h from administration; no significant role if given during acute exacerbation but should be started eventually for improved outcome postop
oral vs. iv corticosteroids
same efficacy as long as absorption is not compromised
Benefit of corticosteroids in asthmatic
Improves B2 receptor sensitivity to agonists
Role of steroids in OR
IV or nothing. No role for inhaled steroids
Which steroid would never be used for asthma/COPD?
Fludrocortisone
Rx used when life-threatening exacerbation remains severe (peak exp flow <40% of baseline) after 1h of intensive therapy
- Magnesium Sulfate 2g over 20 min (may not help, won’t hurt)
- Ketamine
Contraindication to Magnesium treatment in severe asthma exacerbation
Hypermagnesemia or renal failure(?)
norm mag = 1.3-2.4
COPD Exacerbation Risk factors
Smoking Infections Previous hospitalizations Increased age multiple comorbidities Need for long term O2 therapy Severe COPD (stage 3/4) Outpatient use: systemic/inhaled steroids
Key symptom of COPD
Dyspnea
COPD exacerbation lasts for
7-10days
Most common causes of COPD exacerbations
Respiratory infection (viral/bacterial) Air pollution Interruption of maintenance therapy
COPD exacerbation tx
Beta-agonists = 1st line
+cholinergic
+steroid/antibx
- no diff between MDI/neb
- no role for long acting beta agonist during acute exacerbation
COPD exacerbation: additional tx
Prednisone 40mg PO daily x 5 days
- or equivalent dosing of hydrocort/methylprednisolone
- may start with IV steroids and transition to oral
When are antbx not used in COPD?
Pt arrives to OR - intubation triggers COPD exacerbation or an allergy
When are antbx used in COPD?
Pt arrives with fevers, chills, cough potential PNA infxn
Antibiotics chosen in COPD depend on
Hx of antbx use (do NOT use same antbx used w/in past 3 months)
Most common pathogens in COPD exacerbation
Strep pneumoniae
H.flu
Moraxella catarrhalis
Pseudomonas (COPD stages3/4)
COPD antibiotics
Zosyn
Ceftriaxone+azithro+tobra
Post op what MUST be done (COPD)?
Vaccination
- annual influenzae vacc
- Pneomococcal polysaccharide age < 65
- Pneumococcal conjugate age 65+
COPD exacerbation prevention
azithro or erythromycin PO
Which drugs may trigger an exacerbation?
- Propofol with metabisulphites
* esp in heavy smokers
Which drugs should be used in COPD/asthma pts?
- Inhaled anesthetics (bronchodilatory)
- NOT desflurane
- Ketamine
What should be avoided during operation for asthma/COPD risk pts?
- avoid anxiety/pain
- caution with instrumentation
- caution for allergies
- minimize risk of aspiration
