Athsma/COPD

Question 1

Asthma PFTs, flow volume loop

Answer 1

Dec FEV1 and fef 25-75. Extent of decrease reflects severity of obstruction. FEV1 <35% and FEF <20% during attack. Flow volume loop shows scoop on expiratory limb

Question 2

Asthma ABG, X-ray

Answer 2

If FEV1 >50%, will be normal. If <25% PaO2 <60, hypercarbia. Hyperinflation of lung on X-ray

Question 3

Pharm management of asthma

Answer 3

Inhaled or systemic steroids, cromolyn, leukotriene inhibitors, methylxanthines (PDE inhibitors), B2 agonists, anticholinergics (ipratropium).

Question 4

Pre induction considerations

Answer 4

Assess sounds. PFTs before and after bronchodilators for elective operations. Ratio should be >70%. If <50%= severe. Cxr. ABG. Benzos good for anxiety (prev bronchospasm), opioids- consider depression. H2 antagonist (unopposed h1 can lead to bronchoconstriction). C/w schedule asthma meds

Question 5

Pre op bronchoconstriction prophylaxis

Answer 5

Albuterol before induction. Pre op steroids inhaled 48 hrs pre op, IV hydrocortisone 100 mg Q8 if FEV1 <80% or adrenal suppression

Question 6

Asthma anesthesia: goals, how to attain them

Answer 6

Depress a/w reflexes, avoid hyperactivity, tx constriction, avoid histamine release. Regional good. Propofol and ketamine best. Avoid metabisulfite. IV opioids. Lidocaine 1.5 mg/kg IV or LTA

Question 7

Asthma induction/maintenance: VA considerations

Answer 7

> 1.5 MAC for dilation. Need strong cv sys. Sevo and halothane best to avoid coughing

Question 8

Asthma: NDMR to avoid

Answer 8

Atracurium, mivacurium, d tubo

Question 9

Induction agent that releases histamine to avoid. Opioids to avoid for same reason. Also consider avoiding what

Answer 9

Thiopental. Demerol, morphine. Ketorolac and NSAIDs

Question 10

VA to avoid in asthmatic

Answer 10

Des and iso

Question 11

Vent goals asthma

Answer 11

Rr 8-10 (decreased), prolong i:e for adequate expiration time, inc TV to maintain normal paco2, avoid PIP >40

Question 12

Causes other than asthma that can lead to wheezing intraop

Answer 12

Foreign body (gastric tube in lung), kinked ETT, light anesthesia, aspiration, endobronchial intub, ptx, PE, pulm edema

Question 13

What to do if bronchospasm intraop

Answer 13

100% 02, deepen anesthesia w VA/IV meds, B2 agonists. Epi if severe 2-8 mcg/min or sq. Consider 1-2 mg/kg cortisol, IV aminophylline

Question 14

COPD PFT

Answer 14

FEV1/FVC ratio decreased. FEF 25-75 decreased. Increased RV. Normal to increased FRC and TLC

Question 15

What COPD looks like on X-ray (emphysema)

Answer 15

Hyperinflation, flat diaphragm, vertical cardiac silloughette.

Question 16

What chronic bronchitis vs emphysema looks like on ABG

Answer 16

Bronchitis: 02 <60 co2 >45. Emphysema: 02 >60 co2 often normal

Question 17

How emphysema different

Answer 17

thin, accessory muscles, dyspnea, scant sec, diminished breath sounds, R HF, low diaphragm and hyperinflation

Question 18

How bronchitis diff

Answer 18

Overweight, cyanotic, cough, secretions, dim breath sounds (< than emphysema), R HF cor pulm, cxr- inc broncho vascular markings

Question 19

COPD: where we want pao2

Answer 19

60-80 goal for supplemental 02.

Question 20

COPD: inc risk s/s in h&p. Pre op goals

Answer 20

Exercise intolerance, chronic cough, dyspnea, absent breath sounds/wheeze, prolonged exhale. Stop smoking, tx infection, bronchodilation

Question 21

Smoking cessation time marks

Answer 21

12-24 h carboxyhgb drops to 1%. 2-6 wks ciliary func returns. 4-8 weeks reduced complic

Question 22

Meds for COPD

Answer 22

Sympathomimetics (bronchodilation), steroids (edema), PDE inhib (inhib breakdown 3,5 camp), cromolyn (mast cell stab and prev histamine release)

Question 23

Preop COPD tx

Answer 23

Stop 8 weeks or after midnight, abx if infected, 02 for hypoxemia or inc PVR, dilators, hydration

Question 24

Counsel COPD on which complications post op

Answer 24

Atelectasis, bronchospasm. Post op vent, splinting, IS

Question 25

COPD: consid w VA, regional, opioids

Answer 25

VA: blunt reflexes but consider cv fx. Regional: good if extrem or lower abd procedure but not above t6. Tx pain avoid depression

Question 26

Anesthesia vent settings COPD

Answer 26

Tv to keep a/w p <40, 6-8 ml/kg. 6-10 rr. Sufficient exhale time. Consider baseline co2, avoid rapid correction. Spont vent may lead to hypercapnia

Question 27

COPD NO pros and cons

Answer 27

Pro: dec dose VA, quick on and off. Con: ptx and bullae rupture, limits 02 admin

Question 28

COPD: pts that req post op vent commonly

Answer 28

Ratio <0.5 or paco2 >50 pre op