Respiratory Function Flashcards
1
Q
True or false
In a normal lungs, breathing can be performed exclusively by the lungs
A
True
2
Q
The adult tip of the orotracheal tube moves at an average of how many cm by fkexion/extension?
It can travel by as much as how far?
A
- 8 cm
6. 4 cm
3
Q
In infants, displacement by how much can move the tube
A
1 cm
4
Q
The adult RIGHT MAIN STEM BRONCHUS is how long before it branches into lobar bronchi.
A
2.5 cm
5
Q
In 10% of adults, the right upper lobe bronchus departs from the right main stem bronchus less than how long below the carina?
A
2.5 cm
6
Q
True or false
The right upper lobe bronchus opens directly into the trachea, above the carina.
A
True
7
Q
What is the most sensitive clinical index of lung compliance?
A
Spontaneous respiratory rate
8
Q
Carotid and aortic bodies are stimulated at what range of PaO2 values?
A
60 to 65 mmHg
9
Q
What are the three etiologies of hyperventilation.
A
- Arterial hypoxemia
- Metabolic acidemia
- Central etiologies
10
Q
Increase in dead space ventilation increases what factor?
A
CO2 elimination
11
Q
Increase in physiologic shunt affects?
A
Arterial oxygenation
12
Q
What is the ratio of alveolar ventilation to dead space ventilation during SPONTANEOUS VENTILATION?
A
2:1
13
Q
What is the ratio of alveolar ventilation to dead space ventilation during POSITIVE PRESSURE VENTILATION?
A
1:1
14
Q
What is the difference between paco2 vs petco2?
A
Dead space ventilation
15
Q
The most common ACUTE increase in dead space ventilation is?
A
Decreased cardiac output
16
Q
Calculating of what is the best tool for evaluating for the lung’s efficiency in oxygenating the arterial blood.
A
Shunt fraction
17
Q
Pulmonary function tests are requested for only 2 purposes.
A
- To ascertain presence of reversible pulmonary dysfunction
2. Define the severity of advanced pulmonary disease
18
Q
Patients who smoke should be advised to stop smoking for at least how long to decrease postop pulmonary complications.
A
2 months
19
Q
Is one of the most important determinants of the risk of PPC.
A
Operative site
20
Q
The highest risk for PPC is?
A
Nonlaparoscopic upper abdominal operations
Followed by lower abdominal and intrathoracic operations
21
Q
The single most important aspect of postoperative pulmonary care and prevention of PPC is?
A
Early ambulation
22
Q
The sternal angle is located in what thoracic level?
A
T4 or T5
23
Q
This plane separates the superior from the inferior angle.
A
Sternal angle
24
Q
During work of breathing the predominant changes in thoracic diameter occur in the ____ in the upper thoracic region and in the _____ in the lower thorax.
A
Anteroposterior
Lateral or transverse
25
Is the energy expenditure of ventilatory muscles
Work of breathing
26
What are the ventilatory muscles comprised of
1. Diaphragm
2. Intercostal muscles
3. Abdominal muscles
4. Cervical strap muscles
5. Large back and intervertebral muscles of the shoulder girdle
27
During nonstrenuous breathing, what structure performs most of the muscle work.
Diaphragm
28
What are the most powerful muscles of expiration?
Muscles of the abdominal wall
29
Are the most important inspiratory accessory muscles
Cervical strap muscles
30
At FRC, the intrapleural space normally has a slightly subambient pressure which is?
-2 to -3 mmHg
31
The lung parenchyma is subdivided into three airway categories
1. Conductive
2. Transitional
3. Respiratory
32
Conductive airways
Trachea to terminal bronchioles
33
Transitional airways
Respiratory bronchioles (gas transport) to alveolar ducts (limited gas exchange)
34
Respiratory airways
Alveoli to alveolar sacs
35
Conventionally large airways with how much diameter create 90% of total airway resistance
2 mm
36
How much alveoli at birth?
24 million
37
Final adult count of alveoli
By what age is this number reached?
300 million
8 to 9 years old
38
Surface area of alveoli
70 m2
39
Length of trachea
Outer diameter of trachea
10 to 12 cm
20 mm
40
How many U-shaped hyaline cartilages are there?
With the opening of the U facing in what direction?
20
Posteriorly
41
Level of the cricoid cartilage
6th cervical vertebral body
42
Which mediastinum does the trachea enter?
Superior
43
Where does the trachea bifurcates?
Sternal angle (lower border of the fourt thoracic vertebrae)
Half is intrathroracic and half is extrathoracic
44
The adult carina can move superiorly as much as how much?
5 cm
45
In the adult, the right bronchus leaves the trachea at approximately how much angle from the vertical tracheal axis?
Whereas the left bronchus is about?
25 degrees
45 degrees
46
What age in children that the angles created by the left and right main-stem bronchi are approximately equal?
How much take-off angle is there?
3 years old
55 degrees
47
What is the diameter of the bronchioles?
They are devoid of what structure?
What structure are they abundant with?
1 mm
Cartilage
Smooth muscles
48
First site of tracheobronchial tree where gas exchange occurs.
Respiratory bronchioles
49
Right upper lobes (3)
Apical
Anterior
Posterior
50
Right middle lobes (2)
Medial
| Lateral
51
Right lower lobes (5)
```
Superior
Medial basal
Lateral basal
Anterior basal
Posterior basal
```
52
Left upper lobes (2)
Apical posterior
| Anterior
53
Lingular lobes (2)
Superior
| Inferior
54
Left lower lobes
1. Superior
2. Posterior basal
3. Anteromedial basal
4. Lateral basal
55
The alveolar-capillary membrane has 2 functions
1. Transport of gases
| 2. Production of local and humoral substances
56
What type of alveolar cells cover 80% of the alveolar surface.
Type 1
57
Alveolar wall consists of the ff structures (4)
1. Capillary epithelial cells
2. Basement membrane
3. Pulmonary capillary endothelial cell
4. Surfactant lining layer
58
How much enzymatic activity is needed to produce surfactant?
50%
59
These alveolar cells are important in immunologic lung defense.
Type 2
60
Two circulatory system supply blood to the lungs (2)
1. Pulmonary
| 2. Bronchial
61
Lung movements occur due to forces external to the lungs. The response of the lungs to these external forces is governed by two main characteristics
1. Ease of elastic recoil
| 2. Resistance to gas flow
62
How much difference in intrapleural pressure is there during an upright position from top to bottom?
7 cmH2O
63
What is relevant under conditions of laminar flow
Viscosity
64
Read
Turbulent flow : fresh gas will not reach the end of the tube until the amount of gas entering the tube is almost equal to the volume of the tube.
65
4 conditions that will change laminar to turbulent flow
1. High gas flow
2. Sharp angles
3. Branching
4. Decreased diameter
66
True or false
In lamiar flow, resistance is inversely proportional to gas flow rate. In turbulent flow it is in proportion to flow rate.
67
The normal response to increased inspiratory resistance is?
Inc inspiratory effort
Little change in FRC
68
True or false
An increased paco2 in the setting of increased airway resistance warrants serious attention as it suggests that the patient’s compensatory mechanisms are nearly exhausted.
True
69
Acute ventilatory failure secondary to muscle fatigue is evidenced by?
Acute increase in arterial carbon dioxide
Precipitated by pneumonia or heart failure
70
Physiologic aging of the lung is associated with what changes? (4)
1. Dilation of the alveoli
2. Enlargement of airspaces
3. Decrease in surface area
4. Loss of supporting tissue
71
Changes in the aging lung result in decreased lung recoil (elastance) creating?
INCREASED residual volume and FRC
72
Read
With aging, respiratory centers demonstrate decreased responsiveness to hypoxemia and hypercapnia
73
This refers to the act of inspiring and exhaling
Breathing
74
This refers to the movement of gas in and out of the lungs
Ventilation
75
Occurs when energy is released from organic molecules in relation to the movement of gas molecules.
Respiration
76
Term referring to the cessation of ventilatory effort with lungs filled at TLC
Apneusis
77
Inspiratory center
Dorsal medullary reticular formation
78
Serves as the pacemaker for the respiratory system. Also the source of elementary ventilatory rhythmicity.
DRG
79
Serves as the expiratory coordinating center
Ventral respiratory group
80
Electrical stimulation of this area results in inspiratory spasm
Apneustic center
81
Primary function of this area is to limit the depth of inspiration
Pneumotaxic center
82
Stimulation of this area increases the rate and amplitude of ventilation
Reticular activating system
83
Stimulation of the carotid SINUS results in?
Stimulation of the carotid BODY CHEMORECEPTORS results in?
Decreases vasomotor tone and ventilation
Increase in both vasomotor tone and ventilation
84
Which structure facilitate proprioception of the pulmonary system.
Which area has abundance of this structure?
Golgi tendon organs (tendon spindles)
Intercostal muscles
85
The rate of rise of paco2 in anesthetized patients in the first minute and thereafter is?
12 mmHg
3.5 mmHg
86
In awake normal adults, the apneic threshold normally occurs at a PaCO2 of around?
32 mmHg
87
4 drugs stimulate ventilation of peripheral chemoreceptors
1. Aminophylline
2. Doxapram
3. Salicylates
4. Norepinephrine
88
Usually PaCO2 increases up to how much during sleep
10 mmHg
89
In the absence of other ventilatory patterns, this drug induce pathognomonic changes in ventilatory rate and Vt?
Decreased ventilatory rate with increased Vt
90
Barbiturates shift carbon dioxide response curve to the?
What is the ventilatory rate and Vt pattern?
Right
Decreased tidal volume and increased ventilatory rate
91
Diffusion becomes the predominant mode of gas transport?
Terminal bronchioles (sixteenth generation)
92
The most frequent cause of hypoxemia is?
Shunt effect
93
What is the most common reason for a measured decrease in diffusing capacity?
Mismatched ventilation and perfusion
94
This lung zone (lung apex) where pulmonary artery pressure exceeds pulmonary arterial pressure (gravity independent area). PA > Ppa > Ppv
Zone 1 (alveolar dead space ventilation)
95
Well-matched ventilation and perfusion occur in this area. Ppa > PA > Pv
Zone 2
96
Most gravity dependent area. Ppa > Pa > Pv
Zone 3
97
The ideal VQ ratio of 1 is believed to occur approximately the level of what rib?
1st rib
98
Normal V/Q?
Shunt?
Silent unit?
Absolute dead space?
1:1
0:1
0:0
Infinity
99
Increases in dead space ventilation primarily affect carbon dioxide elimination and have little influence on arterial oxygenation until dead space ventilation is of minute ventilation?
How about for physiologic shunt?
80% to 90%
75% to 80%
100
Formula for tidal volume?
Alveolar ventilation (VA) + dead space ventilation (VD)
101
Ratio of alveolar to dead space in a normal person
2:1
102
How much is anatomic dead space?
Location?
2 mL/ideal body weight
Oropharynx to terminal and respiratory bronchioles
103
What is the most likely cause if pulmonary blood decreases?
Decreased cardiac output
104
At rest the required alveolar ventilation to carbon dioxide production of how much?
60 mL/kg/min
105
The most common reason for acute increase in dead space ventilation is?
Decreased cardiac output
106
In spontaneously breathing person normal Vd/Vt is?
In patients on positive pressure ventilation?
0. 33 (0.2 to 0.4)
| 0. 5
107
Refers to areas of the lungs that are ventilated but poorly perfused.
Physiologic dead space
108
Area of the lungs that is perfused but poorly ventilated. Is that portion of the lung that returns to the heart and systemic circulation without receiving oxygen in the lung.
Physiologic shunt
109
How much (%) is a normal intrapulmonary shunt?
5%
110
Value of vital capacity?
60 mL/kg
111
This lung volume is one of the few tests that can detect extrathoracic airway obstruction
Inspiratory capacity
112
Is the gas remaining in the lungs at passive expiration.
Is the gas remaining in the lungs at forced maximal expiration
FRC
Residual volume
113
When a subject lies supine the FRC is reduced by how much%.
10
114
Forced vital capacity is equivalent to?
Vital capacity
115
FVC values less than this is associated with an increased incidence of PPCs.
15 mL/kg
116
Normal FEV1?
FEV1/FVC equal to or more than 75%
117
Difference between restrictive vs obstructive based on FEV1/FVC
Restrictive : normal
| Obstructive : increased
118
Also called the maximum mid expiratory flow rate
Forced expiratory flow
119
Normal forced expiratory flow
4.7 L/sec (280 L/min)
Decreased in obstructive
Normal in restrictive
120
Is the largest volume if gas that can be breathed in 1 minute by voluntary effort. Is the best endurance test that can be performed in the laboratory.
Maximum voluntary ventilation
170 mL/min (healthy young adults)
121
What is the partial pressure of carbon monoxide in the blood
Zero
122
Factors that can influence DLCO (4)
1. Hemoglobin concentration
2. Alveolar paco2
3. Body position
4. Pulmonary capillary blood volume
123
Using spirotmetry measures what pulmary values (3)?
VC
FEV1
FVC
124
Decreased TLC (restrictive or obstructive)?
Restrictive
125
FRC reaches its lowest point in how many minutes after anesthesia?
How about post operatively?
First 10 minutes
12 hours
126
How does smoking affect pulmonary function? (2)
1. Decreases ciliary motility
| 2. Increases sputum
127
How many % of carboxyhemoglobin in non smokers?
In smokers?
1%
8 to 10%
128
Duration of smoking cessation that can DECREASE carbon monoxide to near normal.
12 to 24 hours
129
One of the main and most prevalent risk factor associated with postoperative morbidity.
Smoking
130
NORMALIZATION OF MUCOCILIARY function requires how long abstinence from smoking?
2 to 3 weeks
131
Smoking patients should be advised to STOP SMOKING for how long to elective procedures or for how long to benefit from improved mucociliary function and some reduction in PPC rate.
2 month
| 4 weeks
132
The normal resting respiratory rate for adults is 12 breaths per minute, whereas for postoperative patient it is?
20 breaths per minute
133
After upper abdominal operations, FRC recovers for how many days?
However, with the use of intermittent CPAP by mask, FRC will recover for how fast?
3 to 7
72 hours
134
Does choice of anesthetic technique change the risk of PPC?
No
135
Operations exceeding how many hours are associated with a higher rate of PPCs.
3 hours
