Respirator YSK Flashcards
(143 cards)
1
Q
FUNCTIONS OF THE RESPIRATORY SYSTEM
What is the Gas exchange?
A
Gas exchange o2 taken from atm, supplied to all cells in the body, co2 is a byproduct of metabolism and eliminated. Ventilator muscles respond to impulses from the brainstem, forces are going to generated to increase volume or decrease volume to maintain homeostasis
2
Q
FUNCTIONS OF THE RESPIRATORY SYSTEM
What is the Acid-base balance?
A
Acid-base balance we have peripheral and central chemo receptors, peripheral sense o2 co2 and H+ levels in arterial blood, central chemo receptors co2 H+ in CSF and brain, have effect on brainstem and resp muscles, increase resp or increase volume, or decrease resp or decrease volume
3
Q
FUNCTIONS OF THE RESPIRATORY SYSTEM
What is Phonation?
A
Phonation results in movement of air over the vocal cords
4
Q
FUNCTIONS OF THE RESPIRATORY SYSTEM
What is pulmonary defense?
A
Pulmonary defense laryngeal reflex to prevent aspiration of food or liquid as we swallow. Airway structures that will prevent and eliminate particles in the air we breath
5
Q
FUNCTIONS OF THE RESPIRATORY SYSTEM
What is Metabolism?
A
Metabolism cells in the lungs produce surfactant. Medications such as ACEI act on lungs (Angiotensin I -> Angiotensin II)
6
Q
RESPIRATORY SYSTEM
What is external respiration?
A
External respiration - exchange of gasses between lungs and blood*****
7
Q
RESPIRATORY SYSTEM
What is internal respiration?
A
Internal respiration - Exchange of gasses between the blood and cells***
8
Q
NOSE
Nasal intubation - How would you insert the tube?
A
Apex of nose pushed superiorly with steady gentle pressure while the tube is inserted parallel to the roof of the mouth***
9
Q
PHARYNX
Where does the pharynx?
A
- Lies posterior to the nasal and oral cavities and anterior to the cervical vertebrae (C4-C6)
- Intimately related to trachea and esophagus
10
Q
Pharynx
What are the three portions of the Pharynx?
A
Various portions:
Nasopharynx
Oropharynx
Laryngopharynx
11
Q
LARYNX
What are the
Single cartilage?
A
-Single cartilage formations:
-Thyroid* T for top, sits on top of cricoid cartilage
-Epiglottis*
Cricoid*** beginning of trachea
12
Q
LARYNX
What are the
Paired cartilage?
A
- Paired cartilage formations: serve to give support to the laryngeal structures
- Arytenoid***
- Corniculate***
- Cuneiform***
13
Q
LARYNX
How is the structure for children?
A
- In Children a complete circle of cricoid cartilage can form a seal against the ET tube***
- Age 8-10 start using cuffed tubes
- Younger than 10 years old, narrowest portion is just below the cords at the cricoid cartilage
14
Q
LARYNX
How is the structure for adults?
A
- In adults the space between the vocal cords, are going to be smaller than the cricoid cartilage***** cuff tube is needed
- The narrowest portion of the laryngeal cavity is the space between the vocal cords
15
Q
TRACHEA
Is trachea a fixed structure?
A
Trachea is not a fixed structure** it will move when the head and neck movements
16
Q
TRACHEA
What is the distance from the the incisors to the carina?
A
Carina
Distance 26 cm from incisors to carina
Lidocaine 1-2mg per kg to blunt the cough reflex
17
Q
TRACHEA
How will the ETT move with movement of the patients head?
A
Hoes follows the nose
Nose goes down, the tube will go down because the trachea will go up
(can have a right main stem intubation)
Nose goes up, the tube will go up because the trachea will go down
Trachea will move up if the patient turns head left of right
18
Q
BRONCHI
As the branching becomes more extensive in the bronchial tree, several structural changes present*****
What are the 3 structural changes?
A
As the branching becomes more extensive in the bronchial tree, several structural changes present*****
- 1st structural changes **
- Rings of cartilage, replaced by plates of cartilage
- These plates of cartilage disappear in bronchial
- Then smooth muscles will predominates
- 2nd change, as the amount of cartilage decreases, the amount of smooth muscles increase*****
- 3rd Cells will change from pseudo stratified ciliated epithelium into simple cuboidal in terminal branches**
19
Q
LUNGS
What are the two layers of serous membrane that enclose and protect each lungs?
A
- Two layers of serous membrane (pleural membrane) enclose and protect each lung:
- Outer layer (parietal) (interior chest wall & diaphragm) and inner layer (visceral) (to the lung)
20
Q
LUNGS
What is the plural cavity and where do the lungs extend??
A
- Pleural cavity is a small potential space containing a lubricating fluid secreted by the membranes preventing friction and permitting easy movement (may fill with blood, air, or pus, which lead to problems)
- Lungs extend from the diaphragm to a point superior to the clavicles and lie against the ribs anteriorly and posteriorly (about 1-1.5 inches)
21
Q
LUNGS
What is the Hilus?
Which lung has the cardiac notch?
What is the total lung capacity for each lung in %??
A
- Mediastinal surface of each lung contains a hilus- Entrance and exit site for bronchi, pulmonary vessels, nerves, lymph
- Left lung contains the cardiac notch
- Right lung thicker, broader, somewhat shorter than left
- Total lung capacity: Right- 55%, Left-45%
22
Q
LOBULES
What do the Alveolar-capillary membranes do?
A
Alveolar-capillary membrane- Exchange or respiratory gases between the lungs and blood takes place by diffusion across the alveoli capillary walls*******
23
Q
RESPIRATION
What is the Principle purpose of respiration?
A
-Principle purpose of respiration is to supply the cells of the body with oxygen and remove the carbon dioxide produced by cellular activities
24
Q
RESPIRATION
What are the Three basic processes of respiration?
A
Three basic processes of respiration:
- Pulmonary ventilation - atm and lungs
- External respiration - lungs and blood
- Internal respiration - blood and cells
25
CELLULAR RESPIRATION
What are the Effects of anesthesia on cell metabolism:****
- Effects of anesthesia on cell metabolism:****
- GA typically reduces O2 consumption and CO2 production by ~15%, (metabolism is going to be decreased) which may be further reduced by hypothermia***
- Greatest reduction; cerebral and cardiac O2 consumption****
26
RIB CAGE AND MUSCLES OF RESPIRATION
What muscles are responsible for inspiration in normal breathing?
Normal breathing; diaphragm and external intercostal muscles are responsible for inspiration
27
RIB CAGE AND MUSCLES OF RESPIRATION
How much does the Diaphragm account for what precent of movement to increase in chest volume*****
Diaphragm accounts 75% of movement in increase in chest volume*****
28
RIB CAGE AND MUSCLES OF RESPIRATION
Is Expiration is generally passive?
Expiration is generally passive***** due to passive recoil of the chest wall except in pathologic states
29
TRACHEOBRONCHIAL TREE
How many Alveoli provide gas exchange?
What is the surface area in the lungs?
- ~300 million alveoli provide an enormous membrane for gas exchange
- 750sq ft of surface area in the lungs
30
TRACHEOBRONCHIAL TREE
Gas exchange: begins at what generation?
Gas exchange: begins at generations 17-19*****beginning of resp bronchial down to alveoli sacs, gas exchange can only occur over flat epithelium
31
ALVEOLI
Walls of alveolus asymmetrical:
Thin side
Thick side
Walls of alveolus asymmetrical:
- Thin side; gas exchange*** less than 0.4 microns thick
- Thick side; structural support 1-2 microns thick (Can also partake in solute exchange)
32
Alveoli:
Upright position, largest alveoli are where?
Where are the smallest?
Size is a function of what two things?
-Upright position, largest alveoli at the pulmonary apex (Not compliant because they are near maximally inflated)****
Size is a function of gravity and lung volume****
Bases smallest alveoli
33
PULMONARY CIRCULATION
Bronchial circulation
Bronchial circulation; (comes from left heart) supplies the tracheobronchial tree to the level of respiratory bronchioles (gas exchange occurs from alveoli)
34
PULMONARY CIRCULATION
Pulmonary circulation
Pulmonary circulation; receives total output of the R heart via pulmonary artery
35
PULMONARY CIRCULATION
Where does Deoxygenated blood passes through?
Deoxygenated blood passes through pulmonary capillaries, O2 taken up and CO2 eliminated pulmonary
36
PULMONARY CIRCULATION
Where does Oxygenated blood returned to?
Oxygenated blood returned to L heart by four pulmonary veins
37
INNERVATION
The diaphragm is innervated by the what nerve and arising from what section of the spinal cord?
The diaphragm innervated by the phrenic nerves, arising from the C3-C5 nerve roots******
-25% reduction is seen with palsy or blockage of nerve impulse
38
INNERVATION
What nerve provide ssensory innervation to the tracheobronchial tree?
- Vagus nerves provide sensory innervation to the tracheobronchial tree:
- Vagal activity (mediate bronchial constriction, increase bronchial secretions through muscarinic receptors)
- Sympathetic activity (mediate bronchial dilation, and decrease secretions through beta 2 receptors)
39
BASIC MECHANISM OF BREATHING
Exchange of alveolar gas with fresh gas from the upper airway does what?
Exchange of alveolar gas with fresh gas from the upper airway reoxygenates desaturated blood and eliminates CO2****
40
EFFECTS OF ANESTHESIA ON RESPIRATORY PATTERN
Effects of anesthesia on breathing is related to what two things?
Effects of anesthesia on breathing is related to changes in position and anesthetic agents
41
EFFECTS OF ANESTHESIA ON RESPIRATORY PATTERN
What happens to the supine patient?
Supine patient:
- Proportion of breathing from rib-cage excursion decreases, abdominal breathing predominates
- Diaphragm contracts more effectively
- Inhalational agents; produce rapid shallow breaths
- Nitrous-narcotic techniques; Result in slow, deep breaths
42
EFFECTS OF ANESTHESIA ON RESPIRATORY PATTERN
Induction of anesthesia: Expiration becomes what?
Induction of anesthesia: Expiration becomes active (due to activity of expiratory muscle, this is why you need paralysis)
43
MECHANICS OF BREATHING
What are the three things related to the mechanics of ventilation?
Elastic resistance, surface tension forces, and compliance relate to the mechanics of ventilation
44
MECHANICS OF VENTILATION
Elastic recoil of the lungs is due to what two things?
Elastic recoil of the lungs is due to high content of elastin fibers and surface tension forces acting at the air-fluid interface in alveoli****
45
MECHANICS OF VENTILATION
Surface tension forces tend to do what?
Surface tension forces:
Surface tension forces tend to reduce the gas-fluid interface and favor alveolar collapse
46
MECHANICS OF VENTILATION
Alveolar collapse is Directly related to what? and Inversely related to what?
Alveolar collapse:
Directly proportional to surface tension
Inversely proportional to alveolar size
47
MECHANICS OF VENTILATION
Pulmonary surfactant does what to surface tension?
What is the net effect for the alveoli?
- Pulmonary surfactant decreases alveolar surface tension
- Ability to lower surface tension is directly proportional to its concentration within the alveolus
- Net effect is to stabilize alveoli
48
MECHANICS OF VENTILATION
Compliance is defined as?
Compliance
Defined as CHANGE IN VOLUME DIVIDED BY THE CHANGE IN DISTENDING PRESSURE
49
MECHANICS OF VENTILATION
Lung compliance is affected by what four things?
Lung compliance affected by lung volume, pulmonary blood volume, extravascular lung water, and pathologic processes
(Any condition that destroys lung tissue causes to become fibrotic or edematous, or causes a deficiency in surfactant, or in any way impedes lungs contraction will affect lung compliance)
50
LUNG VOLUMES
Lung volumes are important parameters in respiratory physiology
Sum of all named lung volumes equals what?
Lung capacities represent a combination of what?
- Lung volumes are important parameters in respiratory physiology
- Sum of all named lung volumes equals the maximum to which the lung can be inflated
- Lung capacities represent a combination of two or more volumes
51
Total volume, each normal breath, is about how much?
500ml
52
Inspiratory reserve volume (IRV), maximal additional volume that can be inspired above tidal volume is how much?
3000ml
53
Expiratory reserve volume (ERV), maximal volume that can be expired below tidal volume is how much?
1100ml
54
Residual volume (RV), volume remaining after maximal exhalation, is how much?
1200ml
55
Total lung capaticy (TLC), RV + ERV + V1 + IRV, is about how much?
5800ml
56
Functional residual capacity (FRC), RV + ERV, is about how much?
2300ml
57
FUCTIONAL RESIDUAL CAPACITY
Frc directly proportionally to what and is inversely proportionally to what?
2300 ml in normal adult
- Frc directly proportionally to height and inversely proportionally to weight,
- Gender specific, reduced 10% in females compared to males
- Posture affects FRC
- FRC Will decrease when the patient is moved from upright position to supine or prone position
- Diaphragmatic tone will effect frc
- Lung disease can lower frc
58
CLOSING CAPACITY
Patency of small airways is highly dependent on what?
Patency of small airways is highly dependent on lung volume (they lack cartilagious support to keep them open)
59
CLOSING CAPACITY
Closing capacity is defined as?
Volume at which small airways begins to close in dependent parts of the lung is called the closing capacity
60
CLOSING CAPACITY
Alveoli continue to be perfused but are not ventilated, this promotes hypoxemia because of what?
- Alveoli continue to be perfused but are not ventilated (created a v/q mismatch)
- Hypoxemia is promoted (Shunting profusion but not ventilation)
61
CLOSING CAPACITY
What happens with Closing capacity and age?
Closing capacity rises steadily with age (closing capacity is normally well below FRC)
About mid-60s closing capacity meets or exceeds FRC in upright position
*Perfusion without ventilation = shunting due to closure of the small airways
62
AIRWAY RESISTANCE TO GAS FLOW
Gas flow in the lung is a mixture of what two types of flow?
Gas flow in the lung is a mixture of laminar and turbulent flow
63
AIRWAY RESISTANCE TO GAS FLOW
Laminar flow, where is the highest velocity?
Associated with what Reynolds number?
Laminar flow:
Velocity is highest in center and decreases toward periphery
Associated with a low Reynolds number (<1000)*******
64
EFFECTS OF ANESTHESIA ON
PULMONARY MECHANICS
Effects on lung volumes & compliance:
Induction of anesthesia produces how much of a reduction in FRC?
Effects on lung volumes & compliance:
Induction of anesthesia produces 15-20% reduction in FRC (about 400mls)
65
EFFECTS OF ANESTHESIA ON
PULMONARY MECHANICS
Lung volume is decreased and both chest and lung compliance is reduced secondary to the higher position of what organ?
Positioning may further decrease FRC
What happens to FRC and closing capacity under anesthesia?
Risk of increased intrapulmonary shunting under anesthesia is similar to that what?
Lung volume is decreased and both chest and lung compliance is reduced secondary to the higher position of the diaphragm
Positioning may further decrease FRC xample: steep trendelenburg (for a robotic case)
FRC and closing capacity are generally reduced to the same extent under anesthesia
Risk of increased intrapulmonary shunting under anesthesia is similar to that in the conscious state
- greatest in elderly, obese and with underlying pulmonary disease
* no increased risk in reduction of FRC with paralytics
66
VENTILATION
What is Dead space?
Dead space: (is ventilation without profusion)
67
VENTILATION
Dead space Composed of what two things?
Gases in nonrespiratory airways (conducting airways) (anatomic dead space)
Gases in non-perfused alveoli (alveolar dead space)
68
VENTILATION
What is Physiologic dead space?
Physiologic dead space: (sum of anatomic and alveolar dead space)
~ 2 mL/kg and nearly all anatomic
69
VENTILATION
What are some Factors affecting dead space?
Factors affecting dead space: (posture, position of airway, dead space increase with age, pulm perfusion, pulm vascular disease)
70
What is *Shunting?
Shunt = Perfusion without ventilation
71
What is Deadspace?
Deadspace = Ventilation without perfusion
72
PULMONARY PERFUSION
What are the Factors affecting pulmonary blood volume?
Factors affecting pulmonary blood volume:*****
POSTURE- movement from supine to erect decreases blood volume
POSITIONING- trendelenberg increases blood volume
SYSTEMIC CAPACITANCE- systemic venoconstriction
73
DISTRIBUTION OF PULMONARY PERFUSION
What happens in the three zones?
Zone 1 alveoli dead space - Ventilation no profusion
Zone 2 pul capillary flow is variable, steady
Zone 3 pul capillary flow is continuous, proportional to various gradients that we have in the lungs
74
DISTRIBUTION OF PULMONARY PERFUSION
What is Hypoxic pulmonary vasoconstiction?
Hypoxic pulmonary vasoconstriction**** protective mechanism, partially effective in diverting blood flow away from poorly ventilated, unventilated, or atiliatic lung regions.
(minimize shunt)
(most inhaled anesthetic agents and potent vasodilators (nitpride), decrease the effectiveness of HPV)
If we inhibit the HPV, PaO2 will go down
75
SHUNTS
overall effect is what?
SHUNTS Profusion, no ventilation
| Overall effect; decreased arterial oxygen content
Can overcome some shunts by increase Fio2
76
EFFECTS OF ANESTHESIA
ON GAS EXCHANGE
Abnormalities in gas exchange during anesthesia are common and include:
Abnormalities in gas exchange during anesthesia are common and include:
Decreased FRC
Increased dead space
Hypoventilation
Increased pulmonary shunting
77
OXYGEN TRANSPORT
For every 100ml of blood with a pao2 of 100 how much of o2 is transported?
How much is bound to hemoglobin?
- For every 100ml of blood with a pao2 of 100, only 0.3ml of o2 is transported physically dissolved
- 13.4 ml of o2 is bound to hemoglobin
78
FACTORS INFLUENCING OXYGEN TRANSPORT
Oxyhemoglobin Dissociation Curve
Shift to the R does what?
Shift to the R; affinity of Hb for O2 decreases*****
Remember exercise is the RIGHT thing to do: it causes increased temp, increased 2,3 DPG, increased CO2, and decreased pH, which facilitates unloading of O2 from Hgb in the tissues
79
FACTORS INFLUENCING OXYGEN TRANSPORT
Oxyhemoglobin Dissociation Curve
Shift to the L does what?
Shift to the L; affinity of Hb for O2 increases****** (hold on to it)
80
FACTORS INFLUENCING OXYGEN TRANSPORT
What happens to Carbon monoxide?
Carbon monoxide poisoning binds to hemoglobin and forms carboxyhemoglobin, 240x affinity than o2, this will displace o2, and attach to hemoglobin, cannot carry o2
81
FACTORS INFLUENCING OXYGEN TRANSPORT
What happens with Methemoglobinemia?
Methemoglobinemia hemoglobin is iron in the ferric state (not normal) caused by nitroglycerin over dose, toxicity from prilocaine
82
OXYGEN STORES
Normal O2 stores in adults are about 1500 mL and includes:
Normal O2 stores in adults are about 1500 mL and includes:
Oxygen remaining in the lungs FRC (2300ml, normally) (this is the most important)
Oxygen bound to hemoglobin (13.4ml)
Oxygen dissolved in body fluids (100ml of blood is 0.3ml)
83
OXYGEN STORES
Severe hypoxemia usually occurs within what time?
Severe hypoxemia usually occurs within 90 seconds, preoxygenating can delay this for about 4-5min)
84
OXYGEN STORES
Onset of hypoxemia can be delayed by increasing the FIO2 prior to what?
Onset of hypoxemia can be delayed by increasing the FIO2 prior to the onset of apnea
85
CARBON DIOXIDE
Transported in the blood in three forms:
Transported in the blood in three forms:
Dissolved in solution
Bicarbonate (largest fraction of co2 in the blood)*****
Carbamino compounds Sum of all three forms is the total CO2 content of blood
86
CARBON DIOXIDE
Rate of rise in arterial CO2 tension is generally slower than its fall following acute changes in what?
Rate of rise in arterial CO2 tension is generally slower than its fall following acute changes in ventilation***** (decrease co2 faster than increase co2 based on ventilator changes, based on the sores we have in our body)
First min is going to 4-6torr*****
Every 2-3torr per min after******
If you become apneic, you are increasing Co2 quickly
87
CONTROL OF BREATHING
Spontaneous ventilation is the result of neural activity from where?
Spontaneous ventilation is the result of neural activity in respiratory centers within the brain stem
Regulates respiratory muscles to maintain normal tensions of O2 and CO2 in the body
88
CONTROL OF BREATHING
Central respiratory centers include what two structures?
Central respiratory centers:
Medulla (original crude resp rhythm will originate)
Pontine area (fine tune resp rate and rhythm)
89
CONTROL OF BREATHING
Central sensors are responsible for what?
Central sensors (Chemo receptors, respond to changes in H concentration, in the CSF)
90
CONTROL OF BREATHING
Peripheral sensors are responsible for what?
- Peripheral chemoreceptors (carotid bodies and aortic bodies, respond to a reduce or elevation of Pao2, H, PaCo2)
- Lung receptors (stretch receptors in the airways, inhibit future inspiration when we inspire to much. Protective mechanism, lungs will shorten exhalation period if you are under deflated, hering brewer inflation reflex)
* Hering-Brewer inflation reflex: Lungs inherently shorten exhalation period if under inflated
91
PULMONARY RISK FACTORS
Risk factors for postoperative pulmonary complications include
Risk factors for postoperative pulmonary complications:
Preexisting pulmonary disease*****
Thoracic or upper abdominal surgery****
*These two are the strongest predictors of post-op complications
Prolonged general anesthesia (> 3 hours) the least consistent factor for post op complications
92
OBSTRUCTIVE PULMONARY DISEASE
Hallmark of these disorders is what?
What happens to the FEV1 to FVC ratio in COPD?
Hallmark of these disorders is resistance to airflow*****
FEV1 to FVC ratio will be decreased in COPD****
In COPD will have a increased airway resistance and increased air trapping
Predominance of airway resistance is going to air trappin
93
ASTHMA
Many cells and cellular elements play a role*****
Airway obstruction is going to be a result of what four things?
Airway obstruction is going to be a result of bronchial smooth muscle constriction, increased secretions, and increased airway edema
94
ASTHMA
Inflammation charactery by what?
Inflammation characterized by:****
Recurrent episodes of wheezing, breathlessness, chest tightness, and cough***** usually at night and early morning hours
Episodes are associated with widespread but variable airflow obstruction that is often reversible (this can be reversible)
95
ASTHMA
During an asthma attack, what causes an increase resistance to gas flow at all levels of the lower airways????
During an asthma attack, bronchoconstriction, mucosal edema, and secretions increase resistance to gas flow at all levels of the lower airways****
96
ASTHMA
Related to asthma attacks, what happens to TLC, RV, and FRC?
What is the result of intrapulmonary shunting?
Related to asthma attacks
TLC, RV, and FRC are all increased, prolonged or severe attacks markedly increase the WOB and can fatigue respiratory muscles (due to air trapping and remodeling)
Number of alveolar units with low V/Q ratios increases result in hypoxia due to intra pulm shunting
97
ASTHMA
Treatment:
Not intraoperative
Treatment:
Sympathomimetic agents are the most useful and most commonly used agents. They produce bronchodilation via β2-agonist activity******
98
ASTHMA
Intraoperative bronchospasm:*****
Manifested as?
Intraoperative bronchospasm:*****
Manifested as wheezing, increased PIPs, decreasing exhaled tidal volumes, or a slow rising capnograph waveform (due to bronchoconstriction and increased secretions)
99
ASTHMA
Intraoperative bronchospasm
Treatment?
Treatment:****
Deepen the anesthetic
If wheezing not resolved consider less common causes (blockage of ETT, over-inflation of balloon, or endobronchial intubation)
Pharmacologic intervention (inhalers, steroids)
100
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
WITH ADVANCING DISEASE MALDISTRIBUTION OF BOTH VENTILATION AND PULMONARY RESULTS IN AREAS OF:
Low V/Q ratios**** decrease ventilation and increase profusion (shunting)
High V/Q ratios dead space increased ventilation and decreased perfusion (deadspace)
4/5=0.8 V/Q
101
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Low V/Q ratios
Low V/Q ratios**** decrease ventilation and increase profusion (shunting)
102
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
High V/Q ratios
High V/Q ratios
| dead space increased ventilation and decreased perfusion (deadspace)
103
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Normal V/Q?
4/5=0.8 V/Q
104
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Chronic Bronchitis:
Airflow obstruction is produced by?
Chronic Bronchitis:
“blue bloater syndrome”
Airflow obstruction is produced by secretions and inflammation****
Ventilatory drive less sensitive to arterial CO2 tension*****
105
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Emphysema:
Characteristic increases in?
Emphysema:
Characteristic increases in; RV, FRC, TLC, and RV/TLC ratio*****
Dyspneic patients with emphysema often purse their lips to delay closure of the small airways “pink puffers”*****
106
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Treatment:
Treatment:
o2 therapy can elevate PaCO2 levels in patients with CO2 retention****
107
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Anesthetic Considerations/Preoperative Management:
What interventions may decrease the incidence of post operative pulmonary complications?
Preoperative interventions may decrease the incidence of postoperative pulmonary complications****
Pulmonary hypertension should be optimized (by oxygenation) (think of Hypoxic Pulmonary Vasoconstriction)
108
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Anesthetic Considerations/
Preoperative Management:
What happens to
Carboxyhemoglobin levels and methemoglobin levels?
Carboxyhemoglobin levels and methemoglobin levels may be increased*****(directly related to smoking) theoretical improvements in 24 hours or less
109
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Anesthetic Considerations/
Intraoperative Management:
Nitrous oxide should be avoided in with what type of patients?
Nitrous oxide should be avoided in certain patients***
with pulmonary HTN or Bullae (can explode/pop alveoli, and collapse lung)
110
RESTRICTIVE PULMONARY DISEASE
Characterized by?
Characterized by decreased lung compliance
111
RESTRICTIVE PULMONARY DISEASE
Lung volumes are typically reduced with preservation of normal expiratory flow rates:***
FEV1 and FVC are:
FEV1/FVC ratio is:
Lung volumes are typically reduced with preservation of normal expiratory flow rates:***
FEV1 and FVC are reduced****
FEV1/FVC ratio is normal
112
RESTRICTIVE PULMONARY DISEASE
ANESTHETIC CONSIDERATIONS/ INTRAOPERATIVE MANAGEMENT:
Acute Intrinsic Pulmonary Disorders are at an
Increased risk of barotrauma and volutrauma due to decreased compliance and increased PIP
What should your TV and RR be?
Increased risk of barotrauma and volutrauma*****
decreased compliance and increased PIP (use lower tidal volumes)
TV reduced to 4-8 mL/kg with compensatory rate 14-18
113
PULMONARY EMBOLISM
| Preoperative Considerations:
Venous stasis or hypercoagulability is often contributory to the development of clots
Clots from lower extremities are nearly always from Above the knees
Can originate from Pelvic veins or less commonly from R side of the heart
114
PULMONARY EMBOLISM
Preoperative Considerations:
Factors associated with DVT and PE include
Factors associated with DVT and PE include prolong bed rest, fx on LE, Heart failure, surgery lasting more than 30 mins., hyper coagulation stats, pregnancy post-partum, carcinoma, obesity, surgery on LE,
115
PULMONARY EMBOLISM
Pathophysiology:
Pathophysiology:
Affected area loses its surfactant within hours atelectasis within 24-48 hours
Pulmonary infarction may occur if a large vessel involved and collateral to the bronchial is insufficient
116
PULMONARY EMBOLISM
Diagnosis:
ABG analysis:
CXR:
ECG:
Diagnosis:
ABG analysis: mild hypoxemia with resp alkalosis, due to increase in ventilation
CXR: usually normal
ECG: tachy, signs of acute cor pulmonale (Right bundle branch block, tall peaked T-waves)
117
PULMONARY EMBOLISM
Intraoperative Pulmonary Embolism:
Decrease in EtCO2 concentration is suggestive for PE**** (but its not a specific conformation)
Elevated CVP and PA pressures****
118
ABC’s of arterial blood gas classification:
ABC’s of arterial blood gas classification:
- Acid-base balance
- Blood oxygenation assessment: amount of O2
- Cellular oxygenation assessment: amount of co2
Ph pco2 po2 is directly measured***
*Increased CO2 indicative of lungs failing to adequately excrete acid from some reason or another
119
Normal pH
7.35 – 7.45
120
Normal PaCO2
35 – 45 mmHg
121
Normal PaO2
80 – 100 mmHg
122
Normal HCO3
22 – 26 mEq/L
123
Normal BE
(-)2 – (+)2 mEq/L
124
CLASSIFICATION OF pH
-Acidosis, generally has a depressive effect on the CNS
Less than 7.1
Less than 6.8
-Acidosis, generally has a depressive effect on the CNS
Less than 7.1 is associated with coma
Less than 6.8 is not compatible with life
125
-Alkalosis generally has the ability to excite the CNS
Seizures may present if?
Greater than 7.8?
-Alkalosis generally has the ability to excite the CNS
Seizures may present if the pH remains to high
Greater than 7.8 generally is not compatible with life
126
PaCO2 ASSESSMENT
| -Respiratory acidosis, what happens?
Respiratory acidosis, Lungs are failing to excrete the carbonic acid
127
COMPENSATION EVALUATION
Defined as?
Defined as a return of an abnormal pH towards normal by the component (organ system) that was not primarily affected*****
128
COMPLETE ACID-BASE CLASSIFICATION
By integrating the information in the preceding steps, a complete acid-base classification can be formulated for any arterial blood gas
pH is classified first and PaCO2 is classified second
Final analysis is based on a systematic approach:
Final analysis is based on a systematic approach:
- pH
- PaCO2
- Metabolic status
- Compensation evaluation
- Complete acid-base classification
129
CLINICAL ASSESSMENT AND CAUSES OF
ACID-BASE
DISTURBANCES
Respiratory Alkalosis caused by:
Respiratory Alkalosis: associated with hyperventilation (decreased CO2)
- Pain or anxiety
- Pulmonary embolism
- Atelectasis
- Pneumothorax
- Excessive artificial ventilation
- CNS injury
- Fever
- Hepatic coma
130
CLINICAL ASSESSMENT AND CAUSES OF
ACID-BASE
DISTURBANCES
Respiratory Acidosis caused by:
Respiratory Acidosis: due to respiratory failure (increased CO2)
- Airway obstruction
- Chest wall injury
- Chronic obstructive pulmonary disease
- CNS depression
- Neuromuscular abnormalities
- Pneumonia
- Pulmonary edema
- Cardiopulmonary arrest
131
CLINICAL ASSESSMENT AND CAUSES OF
ACID-BASE
DISTURBANCES
Metabolic Alkalosis caused by:
Metabolic Alkalosis: usually iatrogenic causes (increased HCO3)
- Nasogastric suction
- Diuretic therapy
- Steroid therapy
- Severe vomiting
- Cushing’s disease
- Aldosteronism
132
CLINICAL ASSESSMENT AND CAUSES OF
ACID-BASE
DISTURBANCES
Metabolic Acidosis caused by:
Metabolic Acidosis: (decreased HCO3¬)
- Shock
- Severe diarrhea
- Dehydration
- Diabetic acidosis
- Lactic acidosis
- Renal tubular acidosis
- Renal failure
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PULMONARY ASSESSMENT
Pulmonary function studies:
Pulmonary function studies:
- Determine obstructive or restrictive disease* (based on PFTs)
- Estimate degree of pulmonary dysfunction*
- Assess effectiveness of therapeutic regimen* (if patient is on bronchial dilators or steroids)
134
PULMONARY FUNCTION TESTS
What is FEV1?
FEV1 volume of air expired in one second
135
PULMONARY FUNCTION TESTS
What is FVC?
FVC amount of air exhaled after maximum inspiration
136
PULMONARY FUNCTION TESTS
What is Midexpiratory flow (FEF25-75%)?
Midexpiratory flow (FEF25-75%) forced mid-expiratory flow avg
- half of FVC
137
PULMONARY FUNCTION TESTS
Normally, FEV1/FVC is what?
Normally, FEV1/FVC is ≥ 80% (of predicted value, if it is less than 80% it its going to be indicative of obstructive pulmonary disease)
138
PULMONARY FUNCTION TESTS
FEV1 and FVC are effort BLANK
forced midexpiratory flow (FEF25-75%) is effort BLANK
FEV1 and FVC are effort-DEPENDENT
Forced midexpiratory flow (FEF25-75%) is effort-INDEPENDENT
and may be a more reliable measurement of obstruction***
139
PULMONARY FUNCTION TESTS
A low FEF, may be indicative of?
A low FEF, may be indicative of obstructive pulmonary disease to increase air trapping and increased resistance to flow
140
VALUES
| Normal values for PFTs are predicted for each patient based on?
Normal values for PFTs are predicted for each patient based on
age, height, weight, and sex and are compared with the actual measurement and expressed as a percentage
141
VALUES
Results are considered abnormal if they are less than what %?
Results are considered abnormal if they are less than 80% of the predicted value***
142
VALUES
Obstructive pulmonary disease indicative of:
Obstructive pulmonary disease
(indicative of reduced fev1 to fvc ratio is going to be less than 80%,
if it is less than 50% of predicted value, patients will have dyspnea on exertion,
less than 25% of predicted value, patients will have dyspnea on minimal activity)**
(hallmark signs are increase in airway resistance and air trapping)
<80%- indicative of increased resistance and air trapping
<50%- pt will experience dyspnea on exertion
<25%- pt will experience dyspnea with minimal activity
143
VALUES
Restrictive pulmonary disease indicative of?
Restrictive pulmonary disease
(smaller tinier lungs)
(hallmark sign is decreased lung compliance, key is that lung volumes are going to reduced, perseveration of exp flow rates)
(fev1 and fvc will be reduced but the ratio will be normal)***
Characterized by: decreased lung compliance, decreased lung volumes with preservation of normal expiratory flow rates
Both FEV1 and FVC are reduced- both volumes lower, but the ratio remains the same (≥80%)
