COPD Flashcards
what is COPD
airway outflow obstruction 2/2 chronic bronchitis or emphysema
- obstruction is generally progressive
- may be accompanied by hyperreactivity
- may be partially reversible
- damage to lung parenchyma occurs
= deterioration in the elastic recoil of the lungs; early small airway collapse
= enlargement of air spaces, fibrosis, increased mucus production
chronic bronchitis
obstruction of the small airways
emphysema
enlargement of air sacs
COPD vs. asthma
obstruction in COPD is not reversible or not completely reversible w/ bronchodilators (as opposed to asthma)
risk factors for COPD
- cigarette smoking/2nd hand smoke
- industrial exposure
- ambient air pollution
- alpha1 antitrypsin deficiency (only known genetic abnormality, but accounts for <1% of cases)
anatomical changes in COPD
- enlargement of bronchial mucus glands
- mononuclear inflammation
- emphysema
- bronchoconstriction
- pulmonary fibrosis
s/s COPD
- chronic productive cough
- progressive exercise limitation
(bronchitis = cough, emphysema = dyspnea) - orthopnea
- sputum discoloration
- wheezing
PFT results of COPD
- decreased FEV1/FVC ratio
- decreased FEF 25-75%
- increased RV & noraml to increased FRC & TLC
- scooped expiratory curve on flow/volume loop
CXR results in COPD
hyperinflation
flat diaphragm
vertical cardiac silhouette
ABG results in COPD
chronic bronchitic (blue bloaters) - PaO2 <60mmHg & PaCO>45mmHg
emphysema (pink puffers)
- PaO2>60mmHg & PaCO2 usually normal
s/s emphysema
thin anxious, purse lips accessory muscles dyspnea scant secretions markedly diminished breath sounds RHF w/ pulm infection hyperinflation on CXR
s/s bronchitis
overweight cyanosis/dusky appearance cough copious secretions diminished breath sounds RHF/cor pulmonae increased bronchovascular markings on CXR
goal of COPD treatment
relieve the symptoms
slow the progression
treatment of COPD (chronic tx)
smoking cessation
supplemental O2 to PaO2 60-80 (NC at home)
home O2 is indicated for PaO2<55 or hct >55 or cor pulmonale
preop assessment of COPD patients
exercise intolerance chronic cough dyspnea breath sounds prolonged exhalation smoking
preop optimization of COPD patients
smoking cessation
bronchodilation
eliminate infection
hydration
preop smoking cessation guidelines
12-24hrs = carboxyhgb drops to near-normal levels
2-6 weeks = improved ciliary function (normalization of immune system takes at least 6 weeks)
4-8 weeks = reduction in postop pulmonary complications
BEST stop smoking 2months preop
smoking & surgery
smoking = decreased ciliary motility, increased sputum production, decreased immune function, increased airway reactivity
- increased postop morbidity
- 2-6x risk of postop PNA
- impaired wound healing
PDE inhibitors & COPD
inhibit breakdown of 3,5 cAMP = bronchodilation
cromolyn
mast cell stabilization & inhibition of histamine release = bronchoconstriction prophylaxis
preop education for COPD patients
- counsel re: postop complications (atelectasis, hypercapnea, hypoxemia, secretion retention, bronchospasm)
- explain need for postop mech ventilation
- education re: splinting & IS
COPD patient: induction
- consider regional (
COPD patient: ventilator settings
Tv 6-8mL/kg: keep PIP<40 rr 6-10 allow sufficient I:E ratio avoid barotrauma (autoPEEP) consider baseline PaCO2 -rapid correction to normal may result in metabolic alkalosis
COPD patient: emergence
postop respiratory status = priority
- adequate pain control (good deep breathing & coughing)
- consider prolonged mechanical ventilation
how long does it take the FRC to recover on a normal healthy patient
5-7 days
nitrous oxide in COPD patients?
may decrease dose required of volatiles
BUT
limits the concentration of O2 that can be administered
diffusion into airspaces = bullae rupture & pneumothorax
extubation of COPD patients postop
w/ preop FEV1/FVC <50% or preop PaCO2 >50 –> postop mechanical ventilation is likely
- this is not a complication, this is an expected result of anesthesia/surgery in those w/ mod-severe COPD!
goals of postop mechanical ventilation
PaO2 60-100
PaCO2 to maintain pH 7.35-7.45