APEX Respiratory Pathophysiology Flashcards
Chemicals that contribute to increased airway resistance
Inositol triphosphate
PLC
Leukotrines
Thromboxane A2
Bronchoconstriction MOA
Vagus nerve-
ACH-
m3-Gq on cellulare membrane
PLC converts PIP2 to IP3
Increases CA
Contractio
bronchodilation moa
non cholinergic PNS
VIP on cell membrane
NO
cGMP
Relaxations
——- 2 pathways
catecholamines
b2 receptor on cell membrane
Gs activates AC
Ac converts atp to cAMP
Decreases CA and causes relaxation
cAMP also increase PKA whick causes relaxation in lungs
Anticholinergic drugs
Atropine (crosses BBB)
Glycopyrrolate (doesnt cross BBB)
Ipratropium
Scopalamine
Anticholinergic MOA
M3 antagonism -> decrease IPC -> decrease iCA
anticholinergic side effects
inhibits secretions- dry mouth
urinary retention
blurred vision
B2 MOA
B2 increases cAMP -> decreases iCA
B2 SE
Tachycardia
dysrhythmias
hyperglycemia
tremors
hypokalemia
opposite of BB
Bronchodilator drug classes
Bronchodilators- B2 agonists, anticholinergics
Anti-inflammatories- corticosteroids, cromolyn, leukotriene modifiers
Methylxanthines- theophylline
Anti inflammatory drugs
Corticosteroids- budenoside, fluticasone
Cromolyn
Leukotrine modifiers- montelukast
Corticosteroid MOA
stimulates intracellular steroid receptors
Decreases airway inflammation and hyperresponsiveness
Methylxanthine MOA
Theophylline- inhibits PDE -> increases cAMP
Increases catecholamine release
Inhibits adenosine receptors
Which PFT is most sensitive indicator of small airway disease
Forced expiratory flow 25-75%
Dynamic PFTs
FEV1
FVC
FEV1:FVC ratio
FEF 25-75%
MMV
FEV1:FVC ratio
Normal- 75-80%
Compares the two
differentiates between obstructive and restrictive diseases
<70% indicates Obstructive, restrictive usually normal
FEF 25-75%
AKA MMEF (mid maximal expiratory flow rate)
Normal: 100+/- 25%
Measures airflow in middle of FEV
Most sensitive indicator of small airway disease
Reduced with obstructive
Normal with restrictive
Best PFT of endurance?
Normal- M-140-180L W-80-120L
MMV Maximum voluntary ventilation
Max air that can be inhaled and exhaled in one minute
PFTs measure ____ (3 things)
Static lung volumes- how much air the lungs can hold at one single point in time
Dynamic lung volumes- how quickly air can be moved in and out of the lungs over time
Diffusing capacity- how well the lungs can transfer gas across capillary membrane
Diffusing capcity of o2, co, co2
21
17
400
Respiratory FV loop
Backwards
Starts on right side at 0, then goes down and to left during inspiration, and down and right for expiration
Patient predictors of post op pulmonary complications
Age over 60
CHF
COPD
Smokers (40 pack years)
Low albumin
NOT ASTHMA
What isnt a predictor of post op pulmonary complications?
asthma
ABGs
PFTs
Procedures that increase risk of post op pulmonary complications
2.5 hours and above
Surgical site neck or thoracic region or near diaphgram
GA
What does short term cessation do to pulmonary complications?
nothing- need atleast 6 weeks
at 6 weeks- increased airway function, increased cilia clearance, sputum production, immunity
ARM alveolar recruitment maneuvers
40cmh2o for 8 seconds
then use peep to keep them open
use lowest fio2 bc high fio2 causes atelectasis
Anesthetic considerations for pulmonary complications pre op, intra op, post op
Pre- bronchodilators, corticosteroids, abx, deep breaths
intra- regional instead of GA, short procedures
post- effective analgesia (nerve block, neuraxial opioids, PCA), recruitment maneuvers (cpap, spirometer, deep breathing)
Surgeries with highest risk of pulmonary complications
aortic
thoracic
upper abdominal
What blood test indicates high risk of PPC
albumin <3.5
Obstructive vs restrictive
O- problem getting air out, but can get it out over longer period of time
R- small lung volumes are the problem, cant get volume up high bc restricted
PFT differences between obstructive and restrictive
O- increased FRC, increased RV, TLC
O- decreased FEV1:FVC ratio, decreased fef 25-75%
Obstructive vs restrictive examples
O-COPD, asthma
R- Fibrosis, kyphoscoliosis, obesity
Stimuli for asthma attack
Cold air
Aspirin
Vagal stimulation
Physical activity
Anesthetic considerations for asthma (airway and vent)
Suppression of airway reflexes
Avoid intubation if able- use regional or LMA
Deep extubation should be considered
If awake intubation- lidocaine and opioids will reduce airway activity
Limit inspiratory time, prolong expiratory time
HME will benefit patients with exercise induced asthma
Anesthetic considerations for asthma- drugs
Volatile agents reduce resistance and dilate the airway- sevo may also reduce coughing and spasm
Ketamine only IV drug that bronchodilates, but also causes secretions
prop reduces reflexes
Lido before extubation suppresses refleces
NO BB
Opioids and NMBs that cause bronchoconstriction in asthmatics
Morphine and meperdine
Succ/ atracurium
Acute treatment for bronchospasm
Epi 1mcg/kg
Ketamine 1mg/kg
Lidocaine 1.5mg/kg
NO HYDROCORTISONE- only for chornic
Presentation of bronchospasm (vs asthma)
Wheezing
Decreased breath sounds
Increased resistance
Increased PIP with normal plateau pressure
Increased alpha angle on capnography
Bronchospasm treatment
100% fio2
Deepen anesthetic
Albuterol
Ipratropium
Epi 1mcg/kg iv
Hydrocortisone 2-4mg/kg iv (for future prevention)
