Athsma/COPD Flashcards
Asthma PFTs, flow volume loop
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
Asthma ABG, X-ray
If FEV1 >50%, will be normal. If <25% PaO2 <60, hypercarbia. Hyperinflation of lung on X-ray
Pharm management of asthma
Inhaled or systemic steroids, cromolyn, leukotriene inhibitors, methylxanthines (PDE inhibitors), B2 agonists, anticholinergics (ipratropium).
Pre induction considerations
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
Pre op bronchoconstriction prophylaxis
Albuterol before induction. Pre op steroids inhaled 48 hrs pre op, IV hydrocortisone 100 mg Q8 if FEV1 <80% or adrenal suppression
Asthma anesthesia: goals, how to attain them
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
Asthma induction/maintenance: VA considerations
> 1.5 MAC for dilation. Need strong cv sys. Sevo and halothane best to avoid coughing
Asthma: NDMR to avoid
Atracurium, mivacurium, d tubo
Induction agent that releases histamine to avoid. Opioids to avoid for same reason. Also consider avoiding what
Thiopental. Demerol, morphine. Ketorolac and NSAIDs
VA to avoid in asthmatic
Des and iso
Vent goals asthma
Rr 8-10 (decreased), prolong i:e for adequate expiration time, inc TV to maintain normal paco2, avoid PIP >40
Causes other than asthma that can lead to wheezing intraop
Foreign body (gastric tube in lung), kinked ETT, light anesthesia, aspiration, endobronchial intub, ptx, PE, pulm edema
What to do if bronchospasm intraop
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
COPD PFT
FEV1/FVC ratio decreased. FEF 25-75 decreased. Increased RV. Normal to increased FRC and TLC
What COPD looks like on X-ray (emphysema)
Hyperinflation, flat diaphragm, vertical cardiac silloughette.
What chronic bronchitis vs emphysema looks like on ABG
Bronchitis: 02 <60 co2 >45. Emphysema: 02 >60 co2 often normal
How emphysema different
thin, accessory muscles, dyspnea, scant sec, diminished breath sounds, R HF, low diaphragm and hyperinflation
How bronchitis diff
Overweight, cyanotic, cough, secretions, dim breath sounds (< than emphysema), R HF cor pulm, cxr- inc broncho vascular markings
COPD: where we want pao2
60-80 goal for supplemental 02.
COPD: inc risk s/s in h&p. Pre op goals
Exercise intolerance, chronic cough, dyspnea, absent breath sounds/wheeze, prolonged exhale. Stop smoking, tx infection, bronchodilation
Smoking cessation time marks
12-24 h carboxyhgb drops to 1%. 2-6 wks ciliary func returns. 4-8 weeks reduced complic
Meds for COPD
Sympathomimetics (bronchodilation), steroids (edema), PDE inhib (inhib breakdown 3,5 camp), cromolyn (mast cell stab and prev histamine release)
Preop COPD tx
Stop 8 weeks or after midnight, abx if infected, 02 for hypoxemia or inc PVR, dilators, hydration
Counsel COPD on which complications post op
Atelectasis, bronchospasm. Post op vent, splinting, IS
COPD: consid w VA, regional, opioids
VA: blunt reflexes but consider cv fx. Regional: good if extrem or lower abd procedure but not above t6. Tx pain avoid depression
Anesthesia vent settings COPD
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
COPD NO pros and cons
Pro: dec dose VA, quick on and off. Con: ptx and bullae rupture, limits 02 admin
COPD: pts that req post op vent commonly
Ratio <0.5 or paco2 >50 pre op
