Final Exam Information Flashcards
(268 cards)
1
Q
2 main causes of bronchodilation?
A
- Circulating catecholamines such as epinephrine and norepinephrine
- Non-parasympathetic nerve releases vasoactive intestinal peptide (VIP) and NO
2
Q
What type of G-protein binds with Beta 2 receptors after episode and norepinephrine stimulation to cause bronchodilation?
A
Gs protein
3
Q
7 steps of bronchoconstriction starting with CN X innervation of airway smooth muscle?
A
- CNX innervating airway smooth muscle
- Cholinergic nerve endings release Act to muscarinic receptor-3
- M3 is coupled of Gq protein
- Activated Gq protein activates phospholipase C (PLC)
- PLC activates inositol triphosphate (IP3) - 2nd messenger
- IP3 stimulates calcium release from SR
- Increased calcium leads to bronchoconstriction
4
Q
What type of response does coughing, allergy and infection cause?
A
Inflammatory response mediated by IgE
5
Q
6 mediators of bronchoconstriciton
A
- Cytokines
- Complement
- Bradykinin
- Platelet activtating factors
- Histamine
- Leukotrienes
6
Q
What do non-cholinergic C fibers release that cause bronchoconstriction?
A
- Substance P
- Neurokinin A
- Calcitonin gene related peptide
7
Q
What type of pattern do COPD patients show on PFT?
A
Obstructive pattern
8
Q
Describe the pathology behind COPD
A
Pathologic deterioration in elasticity or recoil within the lung parenchyma, which normally maintains the airways in an open position
9
Q
What are the airways of COPD patients predisposed to?
A
Collapse during exhalation
10
Q
What occurs with the gas velocity in COPD patients?
A
Increase in gas velocity in narrowed bronchiole, which lowers pressure inside the bronchiole and further favors airway collapse
11
Q
What does bronchospasm and obstruction result from with COPD patients?
A
Increased pulmonary secretions
12
Q
3 major characteristics of COPD patients?
A
- Chronic cough
- Progressive exercise limitation
- Expiratory airflow obstruction
13
Q
Patho behind Chronic Bronchitis? (Goblet cells and ciliary 5)
A
- Increased mucous production
- Loss of mucociliary clearance
- Carina = cough
- Inflammation causing more irritation
- Air trapping
14
Q
Patho behind Emphysema
A
- Damage to collagen and elastin fibers
- Airway almost collapse
- Lung fibrosis and loss of elastic recoil is landmark sign of emphysema
- SOB
15
Q
Risk factors for COPD (4)
A
- Tobacco = primary
- Occupational exposure to dust; indoor and outdoor pollution
- Respiratory infection
- Genetic factors causing reduction in alpha 1 antitrypsin causing the enzyme to be too large
16
Q
Clinical profile of COPD patients (9)
A
- Progressive dyspnea
- Chronic cough - mucous secretions
- SOB
- Expiratory airflow obstruction increases in severity
- Decreased breath sounds
- Expiratory wheezes
- Increased A-P diameter
- Hyperinflation in chest x-ray
- Use of accessory muscles
17
Q
PaCO2 characteristics of Emphysema
A
Normal to decreased
18
Q
PaCO2 characteristics of Chronic Bronchitis
A
Increased
19
Q
Mechanism of airway obstruction for Chronic Bronchitis
A
Decreased airway lumen due to mucus and inflammation
20
Q
Mechanism of airway obstruction for Emphysema
A
Loss of elastic recoil
21
Q
Hematocrit in Chronic Bronchitis patients
A
increased
22
Q
Hematocrit in Emphysema patients
A
normal
23
Q
Diffusing capacity in Chronic Bronchitis patients
A
normal
24
Q
Diffusing capacity in Emphysema patients
A
decreased
25
Cor pulmonale severity in Chronic Bronchitis
Marked
26
Cor pulmonale severity in Emphysema
Mild
27
Prognosis of Chronic Bronchitis patients
Poor
28
Prognosis of Emphysema patients
Good
29
PaO2 characteristics in Chronic Bronchitis
Marked decrease (blue bloater)
30
PaO2 characteristics in Emphysema
Modest decrease (pink puffer)
31
Dyspnea in Chronic Bronchitis
Moderate
32
Dyspnea in Emphysema
Severe
33
FeV1 of Chronic Bronchitis and Emphysema patients?
Decreased
34
4 characteristics of the PFT of a COPD patient?
1. Derease FEV1/FVC ratio
2. Greater decrease in the forced expiratory flow between 25% and 75% of vital capacity
3. Increased residual volume
4. Normal to increased FRC and total lung capacity
35
Why do we see an increased residual volume with COPD patients?
Due to slowing of expiratory airflow and gas trapping being prematurely closed airways
36
What capacity is either normal or decreased in COPD patients?
Vital capacity
37
Treatment of COPD (5)
1. Smoking cessation (primary)
2. Oxygen supplementation
3. Bronchodilators are the mainstay of drug therapy for COPD
4. Anticholingergic drugs show greater effect than B2 agonists
5. Inhaled corticosteroids
38
What is the goal of supplemental oxygen administration for COPD patients?
Achieve a PaO2 between 60-80mmHg
39
3 factors required for home oxygen supplementation for COPD patients
1. PaO2 < 55mmHg
2. Hct >55%
3. Evidence of cor pulmonale
40
Effect of bronchodilators in COPD patients
Small increase in FEV1 but may alleviate symptoms by decreasing hyperinflation and dyspnea
41
What is more effective in asthma treatment, B2 agonists or anticholinergics?
B2 agonists
42
When would broad-spectrum antibiotics be helpful in COPD patients?
Acute episode of increased dyspnea associated with excessive or purulent sputum production
43
When should diuretic therapy be considered for COPD patients?
Those with cor pulmonale and right ventricular failure with peripheral edema
44
What are we looking for preoperatively when getting an ABG on a COPD patient?
baseline CO2 and HCO3
45
3 related risk factors for complications with COPD patients undergoing surgical procedures?
1. Operative site near the diaphragm
2. > 3 hour surgical time
3. Muscle relaxants can disrupt normal respiratory muscles
46
Which drugs do we avoid using with COPD patients undergoing surgical procedures?
Those that release histamine
47
Why do we wait for adequate depth of anesthesia before direct laryngoscopy of COPD patients?
They have a hyperactive airway!
48
5 patient related risk factors of postoperative pulmonary complications
1. Age > 60 years
2. ASA class 2 and higher
3. CHF
4. Preexisting pulmonary disease (COPD)
5. Smoker
49
4 procedure related risk factors of postoperative pulmonary complication
1. Emergency surgery
2. Abdominal or thoracic surgery, head and neck surgery, neurosurgery, vascular/aortic aneurysm surgery
3. Prolonged duration of anesthesia > 2.5 hours
4. General anesthesia
50
Test predictors of postoperative pulmonary complication
Albumin level of < 3.5g/dL
51
4 Postoperative procedures utilized to prevent postoperative pulmonary complications?
1. Deep-breathing exercises
2. Incentive spirometry
3. Selective NG tube
4. Postoperative pain control
52
What type of anesthesia best reduces the risk of postoperative pulmonary complications?
Regional
53
Which volatile is the best to use with COPD patients?
Sevo
54
Why do we caution using Des in COPD patients?
because it is irritable to airway
55
What do we consider using prior to tracheal manipulation in COPD patients? (4)
Inhaled anticholinergics are numero uno, beta-agonists, inhaled or IV steroids, IV lidocaine
56
6 Ventilator Management considerations for COPD patients
1. Warm and humid fresh gas for long cases
2. Tidal volume of 6-8 mL/kg
3. Slow respiratory rates (6-10BPM) provide sufficient time for complete exhalation to occur to minimize air trapping
4. Avoid hyperventilation
5. Desflurane causes airway irritation
6. Ensure complete reversal before extubation
57
4 considerations for the emergence phase of COPD patients
1. Full reversal of neuromuscular blockers
2. Rapid shallow breaths of low tidal volume
3. Awake intubation
4. Prevent patient from coughing
58
4 Preoperative risk-reduction strategies to prevent pulmonary complications
1. Smoking cessation for at least 6 weeks
2. Treat evidence of expiratory airflow obstruction
3. Treat respiratory infection with antibiotics
4. Initiate patient education regarding lung volume expansion maneuvers
59
3 intraoperative risk-reduction strategies to prevent pulmonary complications
1. Use minimally invasive surgery techniques when possible
2. Consider regional anesthesia
3. Avoid surgical procedures likely to last longer than 3 hours
60
2 Postoperative risk-reduction strategies to prevent pulmonary complications
1. Institue lung volume expansion maneuvers such as deep breathing and incentive spirometry or CPAP
2. Maximize analgesia
61
What is restrictive lung disease characterized by?
reduced lung compliance and lung volumes
62
Intrinsic causes of restrictive lung disease?
inflammation or scarring of the lung parenchyma
63
Examples of pathology that leads to intrinsic causes of restrictive lung disease?
pulmonary fibrosis, aspiration pneumonia, pulmonary edema
64
Extrinsic causes of restrictive lung disease?
disorders of the pleura, diaphragm, or chest wall that limit lung expansion
65
Examples of pathology that leads to extrinsic causes of restrictive lung disease?
COPD
66
Pathophysiology of restrictive lung disease?
reduces compliance of the lung, pleura, diaphragm or chest wall
67
How does the pathophysiology behind restrictive lung disease effect the work of breathing?
Increases work of breathing, causing rapid but shallow breathing
68
What is the effect of hyperventilation in patients with restrictive lung disease?
Keeps the PaCO2 at normal levels until the restrictive disorder is very severe
69
When is gas exchange effected in restrictive lung disease?
When the disease is advanced
70
Describe scoliosis
Lateral curvature with rotation of the vertebral column
71
Describe kyphosis
anterior flexion of the vertebral column
72
What would severe deformities in kyphoscoliosis lead to?
Chronic alveolar hypoventilation, hypoxemia, pulmonary hypertension, and cor pulmonale
73
What would be considered severe deformity in kyphoscoliosis?
scoliotic angle > 100 degrees
74
When is respiratory failure most likely to occur in patients with kyphoscoliosis?
Those with a vital capacity of less than 45% of the predicted value and a scoliotic angle of more than 110 degrees
75
What are patients with severe kyphoscoliois at increased risk of developing?
Pneumonia and hypoventilation when exposed to central nervous system depressant drugs
76
What type of approach do we use when administering regional blocks in the kyphoscoliotic patients?
paramedian approach
77
What do we know about patients who have supplemental oxygen before they get to the OR?
They will de-sat quickly and require minimal preoperative sedation
78
By how much should you increase your FiO2 for every L oxygen from NC a patient is on?
3-4% increase in FiO2
79
Universal color of oxygen tank
green
80
Universal color of nitrous oxide tank?
blue
81
Universal color of air tank?
yellow
82
Service pressure psi of oxygen tank?
1,900 psi
83
Service pressure psi of nitrous oxide tank?
745 psi
84
Service pressure psi of air tank?
1,900 psi
85
What is the pressure in an oxygen cylinder directly proportional to?
the volume of oxygen in the cylinder
86
When do nitrous oxide tanks start to lose psi?
Nitrous oxide tanks will not lose psi until the tank is 75% consumed
87
What label do we read to figure out the pressure in a tank of gas?
the E cylinder, not the wall outlet
88
Describe Biot's respiration, i.e. ataxic respirator (4)
1. Periodic breathing because the presence of apnea
2. Poor prognosis
3. Neuron damage
4. 2-4 equal breaths, apnea, 2-4 equal breaths
89
Describe cheyne-stokes respirator (4)
1. Periodic breathing with gradual hyperpnea/hypopnea and apnea
2. sleep/hypoxemia/drugs
3. Hypoperfusion of the respiratory centers in the brain
4. Gradual increase in tidal volume and the apnea
90
Describe kussmauls breathing (3)
1. Metabolic acidosis
2. Hyperpnea
3. rapid, deep, labored breathing
91
Causes of kussmauls breathings?
```
K = Ketones (DKA)
U = uremia
S = sepsis
S = salicylates
M = Methanol
A = Aldehydes
(U)
L = Lactic acid
```
92
4 things we would seen on inspection of patients with pulmonary issues?
1. Hyperpnea: Increased rate and tidal volume
2. Hyperventilation
3. Cyanosis: deoxyhgb is 5gm/dL
4. Clubbing of the fingers, especially in those with cardiovascular disease
93
Characteristic chest-xray of emphysema would show?
hyperinflation of the chest and increased anterior/posterior diameter
94
What does a normal lung transmit upon palpation?
Palpable vibratory sensation (fremitus) to the chest wall
95
Describe palpation of the lungs
Place the ulnar aspects of both hands firmly against either side of the chest while the patients says the words "Ninety-nine"
96
Describe fremitus when consolidation such as pneumonia is present?
Will be pronounced over the lung with pneumonia
97
Describe fremitus when a patient has a pleural effusion
fremitus over an effusion will be decreased
98
3 descriptors of the percussion procedure for the lungs
1. Generates audible sounds and vibrations
2. Determines whether underlying tissue is filled with air or fluid
3. Starts at apex, progressively from top to bottom
99
What tone does normal percussion give?
resonance
100
What tone does a pneumothorax give when percussing the lungs?
hyper resonance
101
4 common errors auscultating the lungs
1. listening through patients gown
2. attempting to auscultate in a noisy room
3. interpreting chest hair sounds as adventitious lung sounds
4. auscultating only convenient areas
102
Location of vesicular breath sounds?
majority of lungs
103
location of broncho-vesicular breath sounds?
near the main stem bronchi
104
Location of bronchial breath sounds?
over the trachea
105
Expiratory pitch and intensity of vesicular breath sounds
Pitch: low
Intensity: soft
106
Expiratory pitch and intensity of broncho-vesicular breath sounds
Pitch: medium
Intensity: medium
107
Expiratory pitch and intensity of bronchial breath sounds
Pitch: high
Intensity: usually loud
108
Inspir:Exp duration of vesicular breath sounds
inspir. > expir.
109
Inspir:Exp duration of broncho-vesicular breath sounds
inspir. = expir.
110
Inspir:Exp duration of bronchial breath sounds
expir. > inspir.
111
4 abnormal breath sounds
1. rales (crackles)
2. rhonchi
3. wheezing
4. Stridor - emergency with partial obstruction of airway
112
Electrolyte abnormality seen with removal of parathyroid gland?
hypocalcemia
113
Purpose of PFT?
determine and categorize the nature and severity of obstruction/restriction
114
What is a major pitfall of PFTs?
testing is effort-dependent
115
What are the predicted values of PFT based on?
age, gender, height, race
116
How does height influence PFTs?
Tall person has larger lung volumes
117
How does age influence PFTs?
Volumes decrease with age
118
How does sex influence PFTs?
lung volumes smaller in females
119
How does race influence PFTs?
Smaller volumes in asian, hispanics, and blacks by 12-15%
120
What would be considered an abnormal PFT?
less than 80% of predicted values
121
Describe fixed airway obstructions effect on PFTs
Large goiter causes obstruction in the upper airway leading to plateaus in both inspiratory and expiratory sections on the PFT
122
Describe variable extrathoracic obstructions effect on PFTs
Only the inspiratory limb of the volume-flow loop plateaus
123
What causes closure of the extrathoracic airway in inspiration?
generation of negative intrathoracic pressure
124
3 common causes of variable extra thoracic obstructions?
vocal cord paralysis, vocal cord neoplasms, neoplasm in the neck
125
Describe variable intrathoracic obstruction effect on PFTs
During exhalation, positive intrathoracic pressure narrows the airway and results in plateau of the expiratory limb of the flow-volume loop
126
What will be preserved in patients with variable intrathoracic obstructions?
Forced vital capacity will be preserved, but marked reductions of FEV1
127
2 common causes of variable intrathoracic obstructions
endobronchial tumors, tracheomalacia
128
What is closing volume?
the volume remaining above RV where expiration below FRC closes some airways
129
Describe FRC and closing capacity in relation to age
With age, both are increased but CC is more steeply increased
130
What does normal airway closure depend on?
Age, younger patients do not close until lung volumes are near or at RV
131
Preoperative evaluation of patients undergoing cardiothoracic surgery in focuses on what?
Focus on the extension and severity of disease
132
Thoracic surgery is considered high risk as it is, but which patients are at an even higher risk of complications than normal? (4)
1. advanced age
2. poor general health status
3. COPD
4. One working lung
133
What surgical procedure reduces the incidence of postoperative complications of thoracic surgery patients?
video assisted thoracotomy (VAT)
134
What do we try to optimize the PFT to before thoracic surgery?
as close to 80% of predictive value as possible
135
3 things to consider in a patient who is undergoing thoracic surgery and experiences dyspnea?
1. how bad is it
2. do they have severe exertional dyspnea?
3. Consider post-op vent support
136
4 things to consider in patients who have a cough before thoracic surgery
1. Is is a recurrent, productive cough?
2. Hemoptysis may indicate tumor in the main stem bronchus
3. Get a sputum culture to determine need for ABX
4. coughing increases airway irritability, need to blunt reflexes before intubation
137
Cigarette smoking and the airway (4)
1. Makes airway irritable
2. Causes cough, mucous hyper secretion and airflow obstruction
3. Passive and active smokers are affected
4. Respiratory events such as re-intubation, laryngospasm, bronchospasm, aspiration, hypoventilation and hypoxemia can occur
138
3 CV effects of nicotine?
1. Stimulates the adrenal medulla to secrete adrenaline
2. SNS stimulation causes increases in HR, BP and peripheral vascular resistance
3. Myocardial contractility is increased, leading to an increase in oxygen demand and consumption
139
2 pulmonary effets of nicotine?
1. narrowing of small airways, causing an increase in coming volume
2. hyper-irritable airways
140
4 effects of GA on smokers?
1. atelectasis
2. reduces compliance
3. decreased FRC
4. impaired oxygen exchange
141
Benefits of smoking cessation for 12-24 hours (4)
1. Decreased carboxyhgb (normal < 1.5%, smokers 5-15%)
2. Increased tissue oxygenation
3. Decreased CV nicotine effects
4. Increased secretions and more reactive airways
142
Benefits of smoking cessation for 2 to 4 weeks?
decreased secretions and decreased airway reactivity
143
Benefits of smoking cessation for 5 to 8 weeks?
decreased incidence of post-op complications; improves mucociliary clearance, airway irritability, closing volume
144
What volatile anesthetic do we avoid in smokers?
Desflurane
145
Relate smokers and requirement of analgesic agents
smokers require higher doses of analgesics
146
What receptors effect the emetogenic effects in smokers
alpha 4, beta 2 and alpha 7 acetylcholine receptors
147
Patients at higher risk of respiratory compromise can't do what in an exercise tolerance test?
cannot walk or climb 3 flights of stairs
148
Factors for acute lung injury?
alcohol abuse and pneumonectomy
149
Intraop factors for ALI?
high ventilatory pressures and cautious fluid administration
150
What pathology would you suspect if a chest x-ray showed hyperinflation and increased vascular markings?
emphysema
151
What are good predictors of cardiac complications during surgery?
unstable angina, MI within 6 weeks, arrhythmias
152
What CV pathology warrants postponement of surgery?
Acute MI within 7 days
153
2 main things to look at on a proeoperative ABG?
1. PO2
| 2. O2 saturation
154
What is the significance of hypercapnia on preoperative ABG?
not indicative of postoperative complications
155
What finding on an ABG is indicative of poor surgical outcomes?
O2 sat < 90% (hypoxemia)
156
What is the most common double lumen ETT?
left double lumen
157
Where do we place patient padding for intrathoracic surgeries?
below the head of the neck, shoulders, arms, legs and scrotum in males
158
what patient position is used for thoracic surgery?
lateral decubitus position with the operative or nondependent side up
159
General descriptor of asthma?
Chronic inflammatory disease (hyper-irritability) of the airways that is reversible
160
Describe extrinsic asthma
Also termed allergic asthma, familial, increased levels of IgE in serum
161
Describe intrinsic asthma
Also termed idiosyncratic asthma, which is related to PSNS abnormality
162
Pathogenesis of asthma
Hyper-irritability of the tracheobronchial tree causing local inflammation
163
What is asthma provoked by?
Exposure to irritating stimulus
164
What mediators are released that cause the physiologic changes seen in asthma patients?
mast cells, eosinophils, macrophages, and other mediators
165
What signs do we see with exacerbation of asthma? (4)
1. Contraction of the smooth muscle
2. Airway edema
3. Increased capillary permeability
4. Mucous secretions
166
What is chromalyn sodium?
A mast cell stabilizer
167
Inflammation of what type of muscle is seen in Asthma
inflammation of smooth muscle
168
What receptors innervate the smooth muscle of the lungs?
Beta (bronchodilation) and muscarinic innervation (bronchoconstriction)
169
What Immunoglobulin complex causes the inflammatory response in asthma patients?
IgE
170
What beta agonist would we use in asthma patients?
Albuterol
171
What anticholinergic would we use in asthma patients?
Ipatropium Bromide
172
Risk factors associated with asthma? (7)
1. Lower respiratory viral infections
2. GERD
3. Inhaled irritants
4. Post nasal drip
5. Secondhand smoke
6. Environmental
7. Samter's Triad
173
Lower respiratory viral infection associated as a risk factor for asthma?
Respiratory Syncytial Virus (RSV) infection provokes hyperactivity for up to 6 weeks or longer
174
How do we lower the need for asthma medications in GERD patients?
Treatment of GERD with H2 receptor antagonists
175
Inhaled irritants associated with risk factors for asthma? (4)
1. Dust mites
2. Animal dander
3. Mold
4. Dust
176
What can the effect of inhaled irritant be primarily ablated to?
B2 adrenergic agonists immediately preoperatively
177
Post-nasal drip is the reason for what what in asthmatic patients?
It is the reason why wheezing is worse in the morning
178
What is Samter's Triad?
1. Sensitive to NSAIDS (ASA)
2. Hx of nasal polyps
3. Hx asthma
179
What is the general thought about intubation and reactive airways?
If possible intubation should be avoided in patients with reactive airways as it is associated with an increase in pulmonary complications (utilize regional anesthesia as much as possible)
180
Clinical features associated with asthma?
1. Dyspnea and tachypnea may lead to difficulty speaking
2. Chest tightness and tachycardia
3. Wheezing
4. Dyspnea
5. Coughing
6. Pulsus paradoxus
7. Visible use of accessory muscles
181
Describe pulsus paradoxus
A fall in SBP > 10mmHg during spontaneous inspiration when BP should stay the same or slightly increase
182
What is pulsus paradoxus related to?
Hyperinflation of lungs causes decreased after load to Right and Left Ventricle, as well as, decreased preload to Left Ventricle
183
What is hypoxia?
Decreased tissue supply of oxygen
184
What is the universal finding during asthma attacks?
hypoxemia (PaO2 < 80 mmHg)
185
What is normal PaO2?
80-100 mmHg
186
What is a very common ABG finding after asthma attacks?
Hypocarbia and respiratory alkalosis
187
What is a late sign during asthma attacks?
CO2 retention; Elevated PaCO2 suggests air trapping, respiratory fatigue and impending respiratory failure
188
What is FEV1?
The volume of air that can forcefully exhaled in 1 second
189
FEV1, FEV1/FVC ratio and FEF in asthma patients?
the 25-75% is reduced
190
What is FVC?
The volume of air that can be exhaled with maximum effort after a deep inhalation
191
Describe FVC in asthma?
It is normal but decreased during a severe attack
192
RV in asthma?
markedly increased
193
FRC in asthma?
increased as a result of air trapping
194
Describe EKG and PVR in acute right heart failure
EKG: right ventricle strain with right axis deviation during severe attacks with some PVC
PVR: Increased due to workload of the right heart
195
What occurs with the ventricle during asthmatic attacks?
Ventricular irritability
196
Chest x-ray characteristic of asthma patients?
Hyperinflation
197
What is the mainstay of asthma treatment?
Beta 2 agonist
198
What is the mechanism of action of beta 2 agonists?
They cause an increase in cAMP resulting in smooth muscle relaxation and bronchiole dilation
199
Where do beta 2 agonists have the greatest effect?
Greatest effect on medium and small airways
200
Examples of SABAs?
albuterol (proventil, ventolin)
201
Examples of LABAs?
salmeterol (serevent)
202
Describe anticholinergics and asthma
Slower onset but longer duration of action that Beta 2 Adrenergic Agonists, they are slightly more effective on larger conducting airways
203
Give an example of anticholinergics used in asthma
ipratropium bromide (atrovent) given by nebulizer or metered-dose inhaler
204
Describe leukotrienes
Leukotrienes are 1,000 times more potent bronchial constrictors than histamine so for moderate to severe asthma, leukotriene antagonists have become a mainstay of treatment
205
Example of a leukotriene antagonist
Montelukast (singulair)
206
What is the drug of choice for Samter's Triad
Montelukast
207
What is the effect of inhaled corticosteroids in asthma?
Limit negative systemic effects while still providing potent anti-inflammatory effects on the airways
208
What is the effect of routine use of inhaled corticosteroids in asthma?
Routine use reduces airway reactivity and inflammation which results in improved symptom control and lung function
209
What are oral or parenteral steroids reserved for with asthma patients?
Acute exacerbations of asthma unresponsive to maximal bronchodilator therapy
210
Examples of corticosteroids used for asthma?
Prednisone (prelone) and beclomethasone (vanceril)
211
When is cromolyn sodium used?
prophylactically, it is not useful in acute periods
212
What is the action of cromolyn sodium?
Stabilizes mast cells to reduce IgE mediated release of histamine and leukotrienes
213
Describe immunomodulators
Namely omalizumab, are anti-IgE antibodies reserved for severely allergic asthmatics with elevated IgE levels
214
What is the issue with immunomodulators even though they may decrease steroid requirements in asthma patients?
They have been associated with anaphylaxis
215
How often are immunomodulators given?
Administered SQ every 2 to 4 weeks
216
6 steps in the drug treatment of asthma attacks
1. SABA (causes tachycardia)
2. 1 + ICS (low dose)
3. 2+ LABA
4. 3+ leukotriene inhibitors
5. 4+ immunomodulator (IgE)
6. 5+ oral corticosteroids
217
What is the issue with low dose ICS?
they can cause osteoporosis, PNE, fungal infection of mouth
218
Which patients do we not use immunomodulators in?
Cancer or lymphoma
219
When do we perform PFTs preoperatively?
Only in high risk patients, want to look at the results before and after bronchodilator administration
220
Preoperative considerations for asthma patients? (6)
1. Presence of upper respiratory infection
2. Infection increases airway responsiveness for 2 weeks or more
3. Respiratory complications increased 11-fold for a child with URI and GETA
4. High risk for laryngospasm and bronchospasm
5. Stress dose steroids
6. Prophylactic inhaler
221
What do you do if your patient experiences a severe asthma attack before an elective surgery?
Delay until beta agonist and pulmonologist consult if they don't work
222
How do you induce patients who are experiencing severe asthma attacks before surgery?
1. Block airway reflexes before DL and intubation
2. Relax smooth muscle
3. Prevent release of mediators
4. LTA 4%/4mL of lidocaine
223
What other two meds can be used to induce asthma patients?
Propofol and ketamine are bronchodilators
224
What is the goal of RSI with asthma patients?
Prevent aspiration and asthmatic attack
225
What are the symptoms of severe bronchospasm intraoperatively? (3)
1. Increased airway pressure, peak pressures will increase
2. Upsloping CO2 curves
3. Desaturation
226
What do the signs and symptoms of intra-op bronchospasm mimic?
Light anesthesia
227
What is the dose of lidocaine prior to extubation to suppress airway reflexes?
1-1.5 mg/kg prior to extubation
228
What can apnea or hypoventilation be attributed to after surgery in asthma patients?
1. Respiratory depression caused by opioids and gases
| 2. Residual MR blockade
229
What does ketorolac cause, making it less than ideal for asthma patients?
Increases airway resistance hence avoided in aspirin intolerant asthma
230
4 categories of respiratory function
1. Anesthetic depth and respiratory pattern
2. Mechanism of hypoxemia
3. Atelectasis
4. Pneumoperitoneum
231
Anesthetic depth and respiratory pattern: what does inadequate anesthesia (<1MAC) cause? (3)
1. Hyperventilation
2. Vocalization
3. Breath-holding
232
At 1MAC what happens to the respiratory rate?
RR is slower
233
What happens to FRC when body position changes from upright to supine? When anesthesia has been induced? Muscle paralysis?
Supine: FRC is reduced by 0.5 to 1.0 L
Anesthesia: FRC decreases by 0.4 to 0.5 L
Muscle paralysis: further decrease in FRC
234
What happens to end-expiratory lung volume?
reduced (close to or equal to RV)
235
The average reduction corresponds to around ___% of awake FRC and may contribute to what two things?
20%
1. Altered distribution of ventilation
2. Impaired oxygenation of blood
236
What are the 3 common mechanisms of hypoxemia?
1. Equipment malfunction
2. Hypoventilation
3. Decrased FRC
237
What two things are associated with equipment malfunction?
mechanical failure of anesthesia apparatus to deliver O2 to the patient and improper ETT position
238
What 3 things could occurr regarding mechanical failure of anesthesia apparatus to deliver O2 to the patient?
1. Disconnection from the O2 supply system (usually at the junction of the ETT and the elbow connector)
2. An empty/depleted O2 cylinder
3. Substitution of a nonoxygen cylinder at the O2 yoke because of absence/failure of the pin index
239
What does PISS stand for?
Pin Index Safety System
240
What is the purpose of the PISS system?
| Pin placement for oxygen?
PISS prevents misconnections!
Each cylinder valve has a unique arrangement of pins that corresponds to its intended contents. Pin arrangement matches holes in the yoke which is where the cylinders attach to the gas machine
Pin placement for O2 is 2 and 5!
241
What does DISS stand for?
Diameter Index Safety System
242
What is the purpose of DISS?
Attaches anesthesia machine to wall outlet, prevents placing wrong gas from wall to machine
243
What type of intubation results in almost no ventilation?
Esophageal intubation
244
What position of the head causes the ETT to migrate deeper into the trachea? Cephalad migration of the ETT?
Caudad (deeper): flexion
| Cephalad (outward): extension
245
Is the right or left stem straighter, making it more likely to intubate?
RIGHT!
246
What happens to Vt, airway resistance, lung compliance, and drive to breathe spontaneously with hypoventilation?
- Reduced Vt
- Airway resistance increased d/t reduced FRC, ET intubation, presence of external breathing apparatus and circuitry
- Lung compliance is reduced as a result of FRC
- Pts may have a decreased drive to breathe spontaneously during general anesthesia
247
The effect of decreased FRC on hypoxemia is very significant clinically. What kind of patient is the reduction in FRC more pronounced in?
Obese patients
| The reduction in FRC continues into the postop period
248
What are 4 common causes of decreased FRC?
1. Supine
2. Induction of anesthesia
3. Paralysis
4. Surgical position
249
From upright to the supine position, FRC decreases by how much? This is due to ___ (cm) cephalad displacement of the diaphragm by the abdominal viscera.
- FRC decreases by 0.5 to 1.0 L
| - 4 cm cephalad displacement of the diaphragm
250
What occurs after induction of general anesthesia?
There is a loss of inspiratory tone
251
The magnitude of these changes in FRC related to paralysis depend on what?
Body habitus - the pressure on the diaphragm caused by the weight of the abdominal contents during paralysis is high
252
How does surgical position affect FRC? Trendelenburg position?
Supine position: the abdominal contents force the diaphragm cephalad and reduce FRC
T-burg: abdominal contents push the diaphragm further cephalad (diaphragm must not only ventilate the lungs but also lift the abdominal contents out of the thorax)
253
Surgical position predisposes us to what two things?
decreased FRC & atelectasis
254
The decrease in FRC related to Trendelenburg position is exacerbated in what patients?
Obese
255
What are two additional factors that may decrease pulmonary compliance and FRC?
Increased pulmonary blood volume and the gravitational force on the mediastinal structures
256
What body position will the dependent lung experience a moderate decrease in FRC and is predisposed to atelectasis whereas the independent lung may have increased FRC?
lateral decubitus position
257
Atelectasis appears in approximately what % of all patients who are anesthetized?
90%!
It is seen during spontaneous breathing and after muscle paralysis and whether intravenous or inhaled anesthetics are used
258
How do we prevent atelectasis during anesthesia?
5-10 cmH2O PEEP, indiscriminate use of PEEP in routine anesthesia
259
What does increased intrathoracic pressure from PEEP cause? (2)
it impedes venous return and decreases cardiac output
260
What happens after discontinuation of PEEP?
The lung recollapses rapidly (when you start waking the patient up, turn off PEEP to make sure pt can maintain oxygenation without the PEEP)
261
What drug does not impair muscle tone and does not cause atelectasis? What happens if muscle relaxation is required?
Ketamine
If muscle relaxation is required, atelectasis will appear as with other anesthetics
262
What are the two recruitment maneuvers?
Sigh maneuver and VC maneuver
263
What is the sigh maneuver and why do we use it?
double Vt
advocated to reopen any collapsed lung tissue; airway pressure of 20 cmH2O
264
What is the VC maneuver and why do we use it?
For complete reopening of all collapsed lung tissue
inflation pressure of 40 cmH2O is required for 7-8 seconds (then release bag and put pt back on vent)
265
Why is ventilation of the lungs with pure oxygen not good? Ventilation during anesthesia should be done with what fraction of inspired oxygen?
Pure O2 resulted in rapid reappearance of atelectasis
FiO2 of 0.3 to 0.4 (should be increased only if arterial oxygenation is compromised)
266
If 100% FiO2 causes atelectasis, then why do we preoxygenate/denitrogenate prior to induction?
we want to increase O2 reserve in FRC when pt is still awake so when they go to sleep and become apneic, we have some time before sat goes down - want to buy time! This is especially important in obese pts
267
Pneumoperitoneum: what do we want IAP to be to be at?
<15 mmHg or else bad things will happen...
268
Pneumoperitoneum causes what respiratory changes when IAP > 15 mmHg? (4)
1. Low FRC and VC
2. Formation of atelectasis
3. Reduced respiratory compliance
4. Increased peak airway pressure
