Restrictive Lung Disease Flashcards
(313 cards)
1
Q
What is the hallmark of restrictive lung disease (RLD)?
A
The inability to increase lung volume in proportion to an increase in alveolar pressure.
2
Q
What does restrictive lung disease affect?
A
- lung expansion
- compliance
3
Q
What factors are typically related to the development of restrictive lung disease (RLD)?
A
- Connective tissue diseases
- Environmental factors
- Pulmonary fibrosis
- Conditions increasing alveolar or interstitial fluid
- Diseases limiting chest/diaphragm excursion
4
Q
What pathophysiologic effects does restrictive lung disease (RLD) cause?
A
Reduced surface area for gas diffusion, leading to V/Q mismatch and hypoxia.
5
Q
How is restrictive lung disease (RLD) manifested on pulmonary function tests?
A
- Reduced FEV1 and FVC
- Normal or increased FEV1:FVC ratio
- Reduced DLCO
- All lung volumes decreased, especially TLC
6
Q
What is the principal feature of restrictive lung disease (RLD)?
A
A decrease in total lung capacity (TLC).
7
Q
How is mild restrictive lung disease classified based on TLC?
A
TLC 65-80% of the predicted value.
8
Q
How is moderate restrictive lung disease classified based on TLC?
A
TLC 50-65% of the predicted value.
9
Q
How is severe restrictive lung disease classified based on TLC?
A
TLC less than 50% of the predicted value.
10
Q
What causes pulmonary edema?
A
Intravascular fluid leakage into the interstitial and alveolar space.
11
Q
What are two mechanisms leading to pulmonary edema?
A
- Increased capillary pressure
- Increased capillary permeability
12
Q
What is ‘capillary stress failure’ in the context of pulmonary edema?
A
It results from increased capillary pressure or permeability, causing fluid leakage.
13
Q
How does pulmonary edema typically appear on chest X-ray (CXR)?
A
Bilateral, symmetric perihilar opacities.
14
Q
What is associated with pulmonary edema caused by increased capillary permeability?
A
High concentration protein in the edema fluid.
15
Q
What is typically present in increased-permeability pulmonary edema associated with ARDS?
A
Diffuse alveolar damage.
16
Q
What is a newer diagnostic tool for pulmonary edema?
A
lung ultrasound.
17
Q
What condition is cardiogenic pulmonary edema most often associated with?
A
Acute decompensated heart failure.
18
Q
What symptoms characterize cardiogenic pulmonary edema?
A
- Marked dyspnea
- Tachypnea
- Elevated cardiac pressures
- Pronounced SNS activation
19
Q
When should you suspect cardiogenic pulmonary edema?
A
When a patient has decreased systolic or diastolic cardiac function.
20
Q
What conditions increase the risk of cardiogenic pulmonary edema by acutely increasing preload?
A
- Acute aortic regurgitation
- Acute mitral valve regurgitation
21
Q
What conditions increase afterload and systemic vascular resistance, contributing to cardiogenic pulmonary edema?
A
- Left ventricular outflow tract (LVOT) obstruction
- Mitral stenosis
- hypertension
22
Q
What is another name for negative pressure pulmonary edema (NPPE)?
A
Post-obstructive pulmonary edema.
23
Q
What causes negative pressure pulmonary edema?
A
Relief of an acute upper airway obstruction (e.g., laryngospasm, epiglottitis, tumors, OSA).
24
Q
What physiologic mechanism leads to NPPE?
A
Attempted spontaneous ventilation against obstruction creates negative intrapulmonary pressure, drawing fluid from alveolar capillaries.
25
How does negative intrapleural pressure contribute to NPPE?
It decreases interstitial hydrostatic pressure, increases venous return, and increases left ventricular afterload.
26
What other effects does negative intrathoracic pressure cause in NPPE?
* Intense SNS activation
* Hypertension
* Central displacement of blood volume
## Footnote
these factors increase the transcapillary pressure gradient, causing pulmonary edema.
27
When does pulmonary edema onset typically occur after relieving an obstruction?
Within a few minutes to 2–3 hours.
28
What are the symptoms of negative pressure pulmonary edema?
* Tachypnea
* Cough
* Desaturation
29
What is the typical treatment for negative pressure pulmonary edema?
Supplemental oxygen and maintaining a patent airway.
30
When might mechanical ventilation be necessary in NPPE?
If symptoms are severe, although it is usually needed only briefly.
31
How quickly does radiographic evidence of NPPE resolve?
Within 12–24 hours.
32
How often do acute brain injury pts develop neurogenic pulmonary edema?
small fraction of acute brain injury pts
33
When does neurogenic pulmonary edema typically develop?
Minutes to hours after acute CNS injury.
34
What causes neurogenic pulmonary edema?
A massive outpouring of sympathetic nervous system (SNS) impulses causing generalized vasoconstriction and blood shifting into the pulmonary circulation.
35
What leads to pulmonary edema in neurogenic cases?
Increased pulmonary capillary pressure due to blood translocation into interstitium and alveoli.
36
What additional injuries can pulmonary hypertension and hypervolemia cause in neurogenic pulmonary edema?
Injury to blood vessels in the lungs.
37
What causes re-expansion pulmonary edema (REPE)?
Rapid expansion of a previously collapsed lung.
38
What factors increase the risk of REPE?
* >1 L of fluid or air in the pleural space
* Collapse duration >24 hours
* speed of re-expansion
39
What does the high protein content in edema fluid suggest about REPE pathogenesis?
Enhanced capillary membrane permeability.
40
What is the treatment for re-expansion pulmonary edema?
Supportive care.
41
What drugs are commonly associated with drug-induced pulmonary edema?
Opioids (especially heroin) and cocaine.
## Footnote
These substances can cause significant respiratory issues and complications.
42
What does a high protein concentration in pulmonary edema fluid suggest?
High-permeability pulmonary edema.
## Footnote
This indicates a more severe form of pulmonary edema.
43
What effects does **cocaine** have that contribute to pulmonary edema?
Pulmonary vasoconstriction, acute myocardial ischemia, and myocardial infarction.
## Footnote
These effects can severely impact respiratory function.
44
Can naloxone reverse opioid-induced pulmonary edema?
No, naloxone does not reverse opioid-induced pulmonary edema.
## Footnote
Naloxone is effective for opioid overdose but not for pulmonary edema.
45
How is drug-induced pulmonary edema treated?
Supportive care, which may include intubation and mechanical ventilation.
## Footnote
Treatment focuses on stabilizing the patient's respiratory status.
46
What condition should be suspected if pulmonary edema does not respond to diuretics?
Diffuse alveolar hemorrhage (DAH).
## Footnote
DAH can present similarly to pulmonary edema but requires different management.
47
At what altitudes does high-altitude pulmonary edema (HAPE) typically occur?
Between 2500–5000 meters.
## Footnote
HAPE is a significant risk for climbers and travelers at high altitudes.
48
What factor influences the development of HAPE besides altitude?
The rate of ascent.
## Footnote
Rapid ascent increases the risk of developing HAPE.
49
What physiologic process is presumed to cause HAPE?
Hypoxic pulmonary vasoconstriction leading to increased pulmonary vascular pressure.
## Footnote
This process is a critical mechanism in the pathophysiology of HAPE.
50
When does the onset of HAPE typically occur?
Within 48–72 hours after ascent.
## Footnote
Early recognition of symptoms is crucial for effective management.
51
What is the treatment for high-altitude pulmonary edema?
Oxygen administration and rapid descent from altitude; inhaled nitric oxide may improve oxygenation.
## Footnote
Prompt treatment is essential to prevent serious complications.
52
Should elective surgery be performed on a patient with pulmonary edema?
No, surgery should be delayed and cardiorespiratory function optimized.
## Footnote
Ensuring stable respiratory function is critical before any surgical intervention.
53
What may need to be drained preoperatively in patients with large pleural effusions?
The effusion should be drained.
## Footnote
This helps improve respiratory function prior to surgery.
54
How can hemodynamic monitoring be useful for pts with restrictive lung disease?
* assessment
* treatment
55
What ventilatory strategies are recommended for restrictive lung disease during anesthesia?
Low tidal volumes, respiratory rates of 14–18, plateau pressures <30 cm H₂O, and careful PEEP titration.
## Footnote
These strategies help manage ventilation effectively in patients with restrictive lung disease.
56
What breathing pattern is typical in patients with restrictive lung disease?
Rapid, shallow breathing.
## Footnote
This pattern is a compensatory mechanism for decreased lung compliance.
57
Should tachypnea alone delay extubation in restrictive lung disease patients?
No, extubation decisions should be based on gas exchange and overall assessment, not just tachypnea.
## Footnote
A comprehensive evaluation is necessary for safe extubation.
58
What decreases the risk for aspiration pneumonitis?
* elevating the HOB during intubation & extubation decreases aspiration risk
59
How does aspirated gastric fluid damage the lungs?
It destroys surfactant-producing cells and pulmonary capillary endothelium, causing atelectasis and fluid leakage.
## Footnote
Surfactant is crucial for maintaining lung stability and preventing collapse.
60
What results from the destruction of surfactant and endothelium?
Capillary-permeable pulmonary edema.
## Footnote
This condition leads to fluid accumulation in the lungs, worsening respiratory function.
61
What are the symptoms of chemical pneumonitis?
Abrupt dyspnea, tachycardia, and desaturation.
## Footnote
These symptoms can develop rapidly following exposure to harmful substances.
62
When might CXR findings of aspiration pneumonitis become visible?
6–12 hours after the aspiration event.
## Footnote
Early imaging may not show changes, requiring close monitoring.
63
If a patient aspirates while supine, where is aspiration most likely seen on CXR?
Superior segment of the right lower lobe (RLL).
## Footnote
This is due to the anatomical positioning of the bronchial tree.
64
What initial steps should be taken if aspiration is noted?
Suction the oropharynx and turn the patient to the side.
## Footnote
This helps clear the airway and prevent further aspiration.
65
Does Trendelenburg (head down) positioning prevent aspiration?
No, but it can prevent gastric contents from re-entering the airway once in the pharynx.
## Footnote
It is not a recommended practice for aspiration management.
66
What is the best treatment for aspiration pneumonitis?
Supplemental oxygen and positive end-expiratory pressure (PEEP).
## Footnote
These interventions help improve oxygenation and lung mechanics.
67
Are antibiotics routinely recommended for chemical pneumonitis?
No, unless the patient is symptomatic after 48 hours with positive cultures.
## Footnote
Antibiotics are not effective against chemical irritants but may be needed for secondary infections.
68
What substances in e-cigarettes are associated with EVALI?
THC, vitamin E acetate, nicotine, CBD, and other oils.
## Footnote
Vitamin E acetate has been specifically implicated in lung injury cases.
69
What types of lung injury are seen with EVALI?
Pneumonia, diffuse alveolar damage, acute fibrinous pneumonitis, bronchiolitis, and interstitial lung disease.
## Footnote
These injuries reflect a range of pathological processes affecting lung function.
70
What symptoms are associated with EVALI?
Dyspnea, cough, nausea, vomiting, diarrhea, abdominal pain, chest pain, fever, tachycardia, tachypnea, and hypoxia.
## Footnote
Symptoms may vary widely among patients.
71
What is the treatment for EVALI?
Supportive care, antibiotics, and systemic steroids.
## Footnote
Treatment focuses on managing symptoms and reducing inflammation.
72
What are the CXR findings in EVALI?
findings are similar to the diffuse alveolar damage seen in ARDS.
73
What pulmonary finding is most commonly reported in survivors of severe COVID-19?
Drop in diffusion capacity (DLCO) and directly related to the severity of initial disease process
## Footnote
This finding indicates impaired gas exchange efficiency in the lungs.
74
What patients are at highest risk for long-term pulmonary complications from COVID-19?
Patients requiring mechanical ventilation.
## Footnote
Severe disease and prolonged mechanical support increase the risk of lung damage.
75
What longterm symptoms are common in COVID-19 survivors?
Decreased exercise capacity, hypoxia, and persistent opacities on CT.
## Footnote
These symptoms can significantly affect the quality of life and recovery.
76
Severe COVID can progress to what disease?
persistent inflammatory interstitial lung disease.
77
78
What is the PaO2 level indicative of despite O2 supplementation in the absence of a right-to-left intracardiac shunt?
<60 mmHg
79
What PaCO2 level is consistent with the diagnosis of ARF in the absence of respiratory-compensated metabolic alkalosis?
>50 mmHg
80
What are the key characteristics of ARF?
Abrupt increased PaCO2 and decreased pH
81
In chronic respiratory failure, how is the PaCO2 and pH affected?
PaCO2 is increased, but the pH is normal
82
What does a normal pH in chronic respiratory failure reflect?
Renal compensation for respiratory acidosis
83
What are the three treatment goals of ARF?
* A patent airway
* Hypoxemia correction
* Removal of excess CO2
84
What are the devices that can provide 02?
NC, venturi mask, nonrebreather, or T-piece
85
What is the maximum O2 concentration these devices can typically provide?
Seldom >50%
86
In what condition are these devices helpful?
Mild to moderate V/Q mismatching
87
What should be initiated when these methods fail to maintain PaO2 >60 mmHg?
Continuous positive airway pressure (CPAP)
88
How does CPAP benefit lung volumes?
By opening collapsed alveoli and decreasing right-to-left intrapulmonary shunting
89
What risk does CPAP mask pose, especially in certain patients?
Increased risk of aspiration, especially in patients with N/V
90
What is the adequate level of PaO2 to maintain?
PaO2 >60 mmHg
91
What is the corresponding SpO2 level at which PaO2 >60 mmHg is considered adequate?
SpO2 >90%
92
Fill in the blank: CPAP may increase lung volumes by ______.
opening collapsed alveoli
93
What is volume-cycled ventilation?
Fixed tidal volume (TV) with inflation pressure as dependent variable
## Footnote
This method ensures a set amount of air is delivered to the patient with each breath.
94
What happens when the pressure exceeds the set limit in volume-cycled ventilation?
The pressure relief valve prevents further gas flow and triggers an alarm to alert the provider
## Footnote
This safety feature is crucial to avoid damage to the lungs.
95
What can elevated peak airway pressure (PAP) indicate?
Pulmonary edema, pneumothorax, kinked endotracheal tube (ETT), or a mucous plug
## Footnote
Monitoring PAP is essential for patient safety and effective ventilation.
96
What is a disadvantage of volume-cycled ventilation?
Inability to compensate for leaks in the delivery system
## Footnote
This can lead to inadequate ventilation and oxygenation.
97
What are the primary modes of volume-cycled ventilation?
* Assisted/controlled (A/C) ventilation
* Synchronized intermittent mandatory ventilation (SIMV)
## Footnote
These modes allow for different levels of patient participation in breathing.
98
What does VCV stand for?
Volume controlled ventilation
## Footnote
VCV ensures a set tidal volume is delivered.
99
What is the primary function of A/C ventilation?
Ensures a set number of breaths even if there are no inspiratory efforts
## Footnote
A/C ventilation delivers a tidal volume when negative pressure is sensed.
100
What does SIMV stand for?
Synchronized Intermittent Mandatory Ventilation
## Footnote
SIMV allows spontaneous ventilation while providing mandatory breaths.
101
What are the advantages of SIMV over A/C?
* Use of respiratory muscles
* Lower mean airway pressures
* Prevention of respiratory alkalosis
* Improved patient–ventilator coordination
## Footnote
These advantages make SIMV a preferred choice in certain clinical scenarios.
102
What does PCV stand for?
Pressure-cycled ventilation
## Footnote
PCV is characterized by delivering gas flow until a preset airway pressure is reached.
103
In pressure-cycled ventilation (PCV), what happens to tidal volume?
Tidal volume varies with changes in compliance and airway resistance
## Footnote
This variability affects the effectiveness of ventilation.
104
What is the purpose of fiberoptic bronchoscopy?
Helpful for visualizing the airways and obtaining samples for bx and culture
## Footnote
bx refers to biopsy.
105
What percentage of patients experience pneumothorax (PTX) after transbronchial lung biopsy?
5-10%
## Footnote
PTX can also occur after percutaneous needle biopsy at a rate of 10-20%.
106
What is the major contraindication to pleural biopsy?
Coagulopathy
107
What type of anesthesia is used for mediastinoscopy?
General anesthesia (GA)
108
What dissection technique is used during mediastinoscopy?
Blunt dissection along the pretracheal fascia
## Footnote
This technique permits biopsy of paratracheal lymph nodes down to the level of the carina.
109
List some risks associated with mediastinoscopy.
* Pneumothorax (PTX)
* Mediastinal hemorrhage
* Venous air embolism
* Recurrent laryngeal nerve (RLN) injury
110
How can the mediastinoscope affect the right innominate artery?
It can exert pressure, causing loss of pulses in the right arm and compromise of right carotid artery blood flow
111
What type of drugs should be avoided due to their effects?
Drugs with prolonged respiratory depressant effects should be avoided
## Footnote
These drugs can lead to significant respiratory complications during surgery.
112
What does intraoperative mechanical ventilation facilitate?
Intraoperative mechanical ventilation facilitates optimal oxygenation
## Footnote
This is crucial for maintaining adequate oxygen levels during surgical procedures.
113
What may be necessary due to poor lung compliance?
Increased inspiratory pressures may be necessary
## Footnote
Poor lung compliance can complicate ventilation strategies.
114
What condition contributes to the risk of perioperative pulmonary complications?
RLD contributes to the risk of perioperative pulmonary complications
## Footnote
RLD stands for Restrictive Lung Disease.
115
What is often needed postoperatively in patients with impaired pulmonary function?
Postoperative mechanical ventilation is often needed
## Footnote
This is essential for patients who have difficulty breathing after surgery.
116
What physiological changes occur in the rib cage during pregnancy?
The subcostal angle increases, lower chest wall circumference expands, and the diaphragm moves cephalad.
117
What hormone is responsible for stretching the lower rib cage ligaments during pregnancy?
Relaxin
118
At what week of pregnancy do the changes in rib cage physiology peak?
37th week
119
How much does the diaphragm move up due to the enlarging uterus during pregnancy?
About 4 cm
120
How long does it take for the chest wall to normalize postpartum?
About 6 months postpartum
121
What remains wider about 20% postpartum compared to pre-pregnancy measurements?
The subcostal angle
122
Fill in the blank: Increased levels of _______ cause stretching of the lower rib cage ligaments.
relaxin
123
True or False: The rib cage circumference decreases during pregnancy.
False
124
What lung function measures are associated with obesity?
Decreases in FEV1, FVC, FRC, ERV.
125
What BMI level is associated with decreased RV and TLC?
BMI > 40 kg/m2.
126
In cases of extreme obesity, what happens to FRC in relation to closing volume?
FRC may exceed closing volume and approach RV.
127
How is the FEV1:FVC ratio affected by obesity?
It is usually preserved.
128
What effect does adipose buildup in the anterior abdominal wall have on lung function?
Hinders diaphragmatic movement, diminishes basal lung expansion, and causes closure of peripheral lung units.
129
What are the consequences of adipose buildup on ventilation and oxygenation?
Leads to V/Q abnormalities and hypoxemia, especially during sleep.
130
What do adipose cells release that contributes to systemic inflammation in obesity?
Adipocytokines.
131
Fill in the blank: Obesity-related hypoxemia triggers _______.
systemic inflammation.
132
In quadriplegic patients with injury below T4, how is breathing maintained?
By the diaphragm
## Footnote
This indicates that the diaphragm retains its function in lower injuries.
133
What is the result of higher levels of spinal cord injury in quadriplegic patients?
Diaphragmatic paralysis
## Footnote
This leads to compromised breathing ability.
134
Why is coughing almost totally absent in quadriplegic patients?
Because the diaphragm is active only during inspiration
## Footnote
This limits the ability to generate the force needed for coughing.
135
What occurs during diaphragmatic breathing in quadriplegic patients?
Paradoxical inward motion of the upper thorax during inspiration
## Footnote
This results in diminished tidal volume (TV).
136
What causes mild bronchial constriction in quadriplegic patients?
PNS tone that is unopposed by SNS activity from the spinal cord
## Footnote
This imbalance contributes to respiratory complications.
137
What type of bronchodilators are useful for quadriplegic patients experiencing bronchial constriction?
Anticholinergic bronchodilators
## Footnote
These medications help counteract bronchial constriction.
138
What percentage of patients with Guillain-Barré syndrome require mechanical ventilation?
20-25%
## Footnote
Mechanical ventilation is often needed for an average of 2 months.
139
What is the most common disease affecting neuromuscular transmission that may result in respiratory failure?
Myasthenia gravis
## Footnote
This condition can lead to significant respiratory complications.
140
What complications are patients with Muscular Dystrophy predisposed to?
Pulmonary complications
## Footnote
These complications arise due to muscle weakness.
141
What condition occurs due to inspiratory muscle weakness in patients with Muscular Dystrophy?
Chronic alveolar hypoventilation
## Footnote
This condition affects the ability to properly ventilate the lungs.
142
What effect does expiratory muscle weakness have on patients with Muscular Dystrophy?
Impaired cough
## Footnote
This makes it difficult for patients to clear secretions from the lungs.
143
What may weakness of swallowing muscles in Muscular Dystrophy lead to?
Pulmonary aspiration
## Footnote
This can result in serious respiratory complications.
144
What type of devices may be useful for patients with Muscular Dystrophy?
Nocturnal ventilation devices
## Footnote
These devices assist with breathing during sleep.
145
What type of lung disease can neuromuscular disorders that interfere with skeletal respiratory muscles result in?
Restrictive lung disease
## Footnote
This occurs due to the inability to generate normal respiratory pressures.
146
What are the potential causes of restrictive pulmonary defects?
Abnormalities of the spinal cord, peripheral nerves, NMJ, or skeletal muscles
## Footnote
NMJ refers to neuromuscular junction.
147
How do neuromuscular disorders affect cough effectiveness compared to thoracic cage disorders?
Expiratory muscle weakness prevents adequate expiratory airflow, reducing cough effectiveness
## Footnote
In thoracic cage disorders, effective cough is preserved.
148
What is the dependency of patients with severe neuromuscular disorders regarding ventilation?
They are dependent on their state of wakefulness to maintain adequate ventilation
## Footnote
This means that their ability to ventilate properly is affected by whether they are awake or asleep.
149
What complications may develop during sleep in patients with severe neuromuscular disorders?
Hypoxemia and hypercapnia
## Footnote
These conditions can contribute to the development of cor pulmonale.
150
Fill in the blank: Neuromuscular disorders can lead to _______ due to the inability to generate normal respiratory pressures.
restrictive lung disease
151
True or False: Effective cough is preserved in patients with neuromuscular disorders.
False
## Footnote
Expiratory muscle weakness in these patients prevents adequate cough.
152
What is atelectasis?
Common cause of hypoxemia during mechanical ventilation
## Footnote
Atelectasis refers to the collapse of lung tissue affecting the exchange of oxygen and carbon dioxide.
153
What should be checked in acute desaturation?
ETT migration, kinks, or mucous plugs
## Footnote
ETT stands for endotracheal tube, which can become displaced or obstructed.
154
Is hypoxemia due to atelectasis responsive to an increase in FiO2?
No
## Footnote
FiO2 refers to the fraction of inspired oxygen, and in cases of atelectasis, increasing it does not improve oxygenation.
155
What are other causes of sudden hypoxemia?
Tension PTX and PE, which are usually accompanied by HoTN
## Footnote
PTX stands for pneumothorax, and PE stands for pulmonary embolism. HoTN refers to hypotension.
156
What may be necessary to remove mucous plugs?
Bronchoscopy
## Footnote
Bronchoscopy is a procedure that allows doctors to examine the airways and may be used to clear obstructions.
157
How can atelectasis be identified on lung ultrasound (LUS)?
By bronchogram showing static air
## Footnote
A bronchogram is an imaging technique that visualizes the airways and can indicate the presence of atelectasis.
158
What is the most important predisposing factor for developing nosocomial pneumonia?
Intubation
## Footnote
Also known as ventilator-associated pneumonia (VAP)
159
What causes nosocomial pneumonia in the context of intubation?
Micro-aspiration of contaminated secretions around the ETT cuff
160
What are some potential presentations of barotrauma?
* Subcutaneous emphysema
* Pneumomediastinum
* Pneumoperitoneum
* Pneumopericardium
* Pulmonary interstitial emphysema
* Arterial gas embolism
* Tension pneumothorax
161
What does barotrauma reflect?
Passage of air from ruptured alveoli
162
How does infection affect the risk of barotrauma?
Infection increases the risk by weakening the pulmonary tissue
163
What does Pa02 reflect?
The adequacy of O2 exchange across alveolar capillary membranes
## Footnote
Pa02 is a key measurement in assessing respiratory function.
164
How is the exchange of O2 measured?
By the difference between the alveolar PA02 and the arterial Pa02
## Footnote
This measurement helps in evaluating gas exchange efficiency.
165
What is the formula for evaluating the O2 exchange?
PA02 − Pa02 gradient
## Footnote
This gradient is critical for assessing lung function.
166
What are the uses of the PA02 − Pa02 gradient?
Evaluating gas exchange, lung function, and distinguishing the cause of arterial hypoxemia
## Footnote
Understanding the gradient helps in diagnosing respiratory conditions.
167
What PaO2 level indicates desaturation of arterial blood?
<60 mmHg
168
What are the 3 main causes of arterial hypoxemia?
* V/Q mismatch
* Right-to-left pulmonary shunting
* Hypoventilation
169
How does increasing the FiO2 affect PaO2 in different conditions?
Improves PaO2 in all conditions except significant right-to-left pulmonary shunting
170
What triggers compensatory responses in the body regarding PaO2 levels?
An acute decrease in PaO2 <60 mmHg
171
At what PaO2 level do compensatory responses occur in chronic hypoxemia?
<50 mmHg
172
Name one compensatory response stimulated by low PaO2.
* Carotid body–induced increase in alveolar ventilation
173
What is hypoxic pulmonary vasoconstriction?
A response to divert blood flow away from hypoxic alveoli
174
How does increased SNS activity affect oxygen delivery?
Increases cardiac output (COP) and enhances tissue oxygen delivery
175
What does chronic hypoxemia lead to in terms of RBC mass?
An increase in RBC mass to improve O2 carrying capacity
## Footnote
Chronic hypoxemia refers to prolonged low oxygen levels in the blood, which stimulates erythropoiesis.
176
What does the dead space: tidal volume ratio (VD:VT) reflect?
The efficacy of CO2 transfer across alveolar capillary membranes
## Footnote
This ratio helps assess how well carbon dioxide is being exchanged in the lungs.
177
What do areas in the lungs that receive adequate ventilation but inadequate blood flow indicate?
Wasted or dead space
## Footnote
These areas contribute to ineffective gas exchange.
178
What is the normal value for the VD:VT ratio?
<0.3
## Footnote
This indicates a healthy balance between ventilation and perfusion.
179
When may the VD:VT ratio increase to ≥0.6?
When there is an increase in dead space ventilation
## Footnote
This can occur in various respiratory conditions.
180
In which conditions does an increased VD:VT ratio occur?
* Acute respiratory failure (ARF)
* Decreases in cardiac output
* Pulmonary embolism
## Footnote
These conditions lead to impaired gas exchange and altered ventilation-perfusion matching.
181
What is intrapulmonary shunt?
Right-to-left pulmonary shunting: perfusion of nonventilated alveoli.
182
What is the net effect of an intrapulmonary shunt on PaO2?
The net effect is a decrease in PaO2.
183
What does the shunt fraction assess?
The shunt fraction provides an assessment of V/Q matching and an estimate of the response to treatments.
184
What percentage of cardiac output does a physiologic shunt represent?
A physiologic shunt is 2-5% of cardiac output.
185
What does the physiologic shunt reflect?
It reflects the passage of pulmonary arterial blood directly to the left side of the circulation through the bronchial and thebesian veins.
186
How is the shunt fraction calculated?
Calculation of the shunt fraction obtained when the patient breathes 100% O2 eliminates the contribution of V/Q mismatching.
187
What are the considerations for determining if the patient can tolerate extubation?
The patient is alert and cooperative and can tolerate spontaneous ventilation without tachypnea, tachycardia, or respiratory distress.
## Footnote
These factors are critical for ensuring that the patient can maintain adequate respiratory function post-extubation.
188
What is the minimum vital capacity required for extubation?
>15 mL/kg
## Footnote
A vital capacity above this threshold indicates sufficient lung function for extubation.
189
What should the alveolar-arterial oxygen difference be for extubation?
<350 cmH2O on 100% O2
## Footnote
This measurement helps assess the patient's oxygenation status before extubation.
190
What is the required PaO2 level on FiO2 of <0.5 for extubation?
>60 mm Hg
## Footnote
Adequate PaO2 levels indicate that the patient is oxygenating sufficiently at lower concentrations of oxygen.
191
What is the negative inspiratory pressure threshold for considering extubation?
More than −20 cmH2O
## Footnote
This measure reflects the patient's ability to generate sufficient negative pressure for effective ventilation.
192
What pH level is considered normal for extubation?
Normal pHa
## Footnote
A normal pH indicates that the patient's acid-base status is stable, which is important for respiratory function.
193
What is the maximum respiratory rate (RR) allowed for extubation?
<20
## Footnote
A respiratory rate below this limit suggests adequate ventilation and respiratory stability.
194
What is the VD:VT ratio threshold for extubation?
< 0.6
## Footnote
This ratio assesses the efficiency of ventilation, indicating that the patient is able to participate in effective gas exchange.
195
What does rapid RR with low TV usually signify?
An inability to tolerate extubation
## Footnote
RR stands for respiratory rate and TV stands for tidal volume.
196
What is the first option considered when a patient appears ready for a trial of vent withdrawal?
SIMV, which allows progressively fewer mandatory breaths until the patient is breathing on their own
197
What is the second option considered for vent withdrawal trials?
Intermittent trials of total removal of mechanical support
198
What is the third option for vent withdrawal trials?
Use of decreasing levels of pressure support ventilation
199
What should the PaO2 remain above on FiO2 <0.5?
>60 mmHg
200
What is the maximum level for PaCO2?
<50 mmHg
201
What should the pHa remain above for vent weaning?
>7.30
202
What is the maximum PEEP allowed for vent weaning?
<5 cmH2O
203
What is the maximum respiratory rate (RR) allowed?
<20
204
What is the minimum vital capacity (VC) required for vent weaning?
>15 mL/kg
205
What level of alertness should patients have prior to extubation?
Patients should be alert with active laryngeal reflexes
206
What ability should patients have after extubation?
Ability to cough and clear secretions
207
Why is supplemental O2 often needed after extubation?
Due to V/Q mismatching
208
What is ARDS caused by?
Inflammation and manifests as acute hypoxemic respiratory failure
## Footnote
Acute Respiratory Distress Syndrome (ARDS) is primarily the result of inflammation in the lungs.
209
What condition is associated with the highest risk of ARDS?
Sepsis
## Footnote
Sepsis significantly increases the likelihood of developing ARDS due to systemic inflammation.
210
What are the symptoms of ARDS?
Rapid-onset respiratory failure, hypoxemia, and CXR findings similar to cardiogenic pulmonary edema
## Footnote
Chest X-ray (CXR) findings in ARDS can often resemble those seen in heart failure.
211
What effect do proinflammatory cytokines have in ARDS?
Increase alveolar capillary membrane permeability and alveolar edema
## Footnote
This permeability leads to fluid accumulation in the alveoli, worsening respiratory function.
212
What is the typical resolution of acute ARDS?
Usually resolves, but may progress to fibrosing alveolitis with persistent arterial hypoxemia and decreased pulmonary compliance
## Footnote
Fibrosing alveolitis can result in long-term respiratory issues.
213
What are the components of supportive care for ARDS?
Ventilation, antibiotics, DVT prophylaxis, and early enteral feeding
## Footnote
Supportive care is crucial for managing ARDS and improving patient outcomes.
214
What is the primary purpose of prone positioning?
To exploit gravity and repositioning of the heart to recruit lung units and improve V/Q matching
## Footnote
V/Q matching refers to the matching of ventilation (V) and perfusion (Q) in the lungs for optimal gas exchange.
215
When is ECMO typically considered?
In cases of severe hypoxemic/hypercapnic respiratory failure
## Footnote
ECMO stands for extracorporeal membrane oxygenation, a life-support technique used in critical care.
216
What is the aim of using ECMO and prone positioning in respiratory failure?
To rest the lungs until hypoxemia and respiratory acidosis resolve
217
List additional supportive therapies for respiratory failure.
* Fluid management
* Neuromuscular blocking agents (NMB)
* Inhaled nitric oxide
* Prostacyclins (PGI2)
* Recruitment maneuvers
* Surfactant replacement
* Glucocorticoids
* Ketoconazole
218
Fill in the blank: Prone positioning improves _______ matching.
[V/Q]
219
What does ILD stand for?
Interstitial Lung Disease
## Footnote
ILD refers to a group of lung pathologies leading to diffuse parenchymal disease.
220
Name three examples of Interstitial Lung Disease (ILD).
* Sarcoidosis
* Hypersensitivity Pneumonia
* Pulmonary Langerhans Cell Histiocytosis
* Pulmonary Alveolar Proteinosis
* Lymphangioleiomyomatosis
## Footnote
These diseases represent different forms of ILD.
221
What are common symptoms of patients with ILD?
Dyspnea & nonproductive cough
## Footnote
These symptoms can progress to chronic restrictive lung disease.
222
Fill in the blank: Progressive pulmonary fibrosis causes loss of pulmonary vasculature, leading to _______ and cor pulmonale.
pulmonary hypertension
223
What is the outcome of progressive pulmonary fibrosis in terms of pulmonary health?
Loss of pulmonary vasculature, leading to pulmonary hypertension and cor pulmonale
## Footnote
Cor pulmonale refers to the alteration of the structure and function of the right ventricle of the heart due to lung disease.
224
What is sarcoidosis?
Systemic granulomatous disorder involving many tissues, mainly the lungs and thoracic lymph nodes
## Footnote
Sarcoidosis is characterized by the formation of granulomas, which are small clusters of immune cells.
225
How is sarcoidosis often identified?
Identified incidentally on CXR
## Footnote
CXR refers to chest X-ray, which is a common imaging method used to detect abnormalities in the lungs.
226
What are common symptoms of sarcoidosis?
Wheezing, dyspnea & cough
## Footnote
Dyspnea refers to difficulty breathing, while wheezing is a high-pitched sound made while breathing.
227
What cardiac condition can myocardial sarcoidosis cause?
Dysrhythmias
## Footnote
Dysrhythmias are irregular heartbeats that can lead to serious complications.
228
What neurological condition is associated with sarcoidosis?
Unilateral facial nerve palsy
## Footnote
This condition can lead to weakness or paralysis on one side of the face.
229
What is a common respiratory manifestation of sarcoidosis?
Endobronchial sarcoid
## Footnote
Endobronchial sarcoid refers to granulomas that develop within the airways.
230
What percentage of sarcoidosis cases may involve laryngeal sarcoidosis?
Up to 5%
## Footnote
Laryngeal sarcoidosis can interfere with intubation, complicating airway management.
231
What cardiovascular condition may develop due to sarcoidosis?
Cor pulmonale
## Footnote
Cor pulmonale is a condition that results from increased pressure in the pulmonary arteries, leading to right heart failure.
232
What is a classic manifestation of sarcoidosis?
Hypercalcemia
## Footnote
Hypercalcemia refers to elevated calcium levels in the blood, which can occur due to granuloma formation.
233
What enzyme activity is increased in sarcoidosis?
Angiotensin-converting enzyme activity
## Footnote
It is produced by granuloma cells.
234
What are other markers associated with sarcoidosis?
* Serum amyloid A
* Adenosine deaminase
* Serum soluble IL2 receptor
## Footnote
These markers can indicate the presence of sarcoidosis.
235
What test is used to detect sarcoidosis?
Kveim skin test
## Footnote
It is similar to the TB test.
236
What procedures can be used to obtain tissue or lavage fluid for diagnosis of sarcoidosis?
* Mediastinoscopy
* Bronchoscopy
## Footnote
These procedures help in obtaining samples for diagnosis.
237
What treatment is commonly used to suppress symptoms of sarcoidosis?
Corticosteroids
## Footnote
They are also used to treat hypercalcemia.
238
What can advanced pulmonary fibrosis lead to?
Pulmonary hypertension
## Footnote
This is a serious complication of advanced pulmonary fibrosis.
239
What type of inflammation occurs after inhalation of fungus/spores particles?
Interstitial granulomatous inflammation
## Footnote
This condition can present in different forms: acute, subacute, or chronic.
240
What are the symptoms of interstitial granulomatous inflammation after inhalation?
Dyspnea & cough 4-6 hours after inhalation, followed by leukocytosis, eosinophilia, and hypoxemia
## Footnote
These symptoms reflect the body's response to inhaled antigens.
241
What does a CT scan show in cases of interstitial granulomatous inflammation?
Ground-glass opacities in the mid to upper lung zones
## Footnote
This imaging finding is characteristic of the condition.
242
What are the diagnostic methods for interstitial granulomatous inflammation?
Bronchoscopy, trans-tracheal or bronchial biopsy, and cryobiopsy
## Footnote
These procedures help confirm the diagnosis and assess the extent of the disease.
243
What can repeated episodes of interstitial granulomatous inflammation lead to?
Pulmonary fibrosis
## Footnote
This complication arises from chronic inflammation and scarring of lung tissue.
244
What are the treatment options for interstitial granulomatous inflammation?
Antigen avoidance, glucocorticoids, and lung transplant
## Footnote
Treatment focuses on reducing inflammation and managing symptoms.
245
What condition has a strong association with smoking tobacco?
Destruction of the bronchiolar wall and surrounding parenchyma
## Footnote
This condition is often characterized by inflammation around smaller bronchioles.
246
Which areas of the lung are usually affected by this condition?
Upper and middle zones of the lung
## Footnote
The damage is primarily localized to these regions.
247
What does a CT scan show in Pulmonary Langerhans Cell Histiocytosis?
Cysts or honeycombing in upper zones with costophrenic sparing
## Footnote
Costophrenic sparing refers to the preservation of the costophrenic angles in imaging.
248
What findings are observed in a lung biopsy for Pulmonary Langerhans Cell Histiocytosis?
Inflammatory lesions around the bronchioles containing:
* Langerhans cells
* Eosinophils
* Lymphocytes
* Neutrophils
## Footnote
These cellular components indicate an inflammatory response.
249
What is the primary treatment for Pulmonary Langerhans Cell Histiocytosis?
Smoking cessation, systemic glucocorticoids, and symptomatic support
## Footnote
Treatment aims to reduce inflammation and support lung function.
250
What disease is characterized by lipid-rich protein material in the alveoli?
Lipoid pneumonia
## Footnote
Lipoid pneumonia is a condition that can lead to respiratory issues due to the accumulation of lipid material in the lungs.
251
At what age range does lipoid pneumonia usually present?
In the 40s-50s
## Footnote
Symptoms typically include dyspnea and hypoxemia.
252
What are some conditions that may be associated with lipoid pneumonia?
* Chemotherapy
* AIDS
* Inhaled dust
## Footnote
These associations indicate that lipoid pneumonia can occur independently or as a result of other health issues.
253
What does a chest X-ray show in cases of lipoid pneumonia?
Batwing alveolar opacities in middle and lower lung zones
## Footnote
This specific radiographic finding aids in the diagnosis of the condition.
254
What is the treatment for severe cases of lipoid pneumonia?
Lung lavage under general anesthesia to remove the alveolar material and improve macrophage function
## Footnote
Lung lavage is a procedure that helps clear the lungs of lipid material.
255
What airway management technique is used during anesthesia for lung lavage?
Double-lumen tube (DLT) to lavage each lung separately
## Footnote
This technique allows for optimized oxygenation during the lavage procedure.
256
Fill in the blank: Lipoid pneumonia usually presents with symptoms of _______ and hypoxemia.
dyspnea
## Footnote
Dyspnea refers to difficulty breathing, which is a common symptom in this condition.
257
What is the rare multisystem disease that causes proliferation of smooth muscle of the airways, lymphatics, and blood vessels?
Lymphangioleiomyomatosis (LAM)
## Footnote
LAM primarily affects women of reproductive age.
258
Which demographic is most commonly affected by Lymphangioleiomyomatosis?
Women of reproductive age
## Footnote
This disease predominantly occurs in this specific demographic.
259
What do pulmonary function tests (PFTs) show in patients with Lymphangioleiomyomatosis?
Restrictive & obstructive disease with decreased diffusing capacity
## Footnote
These findings indicate impaired lung function.
260
List some symptoms of Lymphangioleiomyomatosis.
* Dyspnea
* Hemoptysis
* Recurrent pneumothorax
* Pleural effusions
## Footnote
These symptoms reflect the disease's impact on respiratory function.
261
What is the treatment for Lymphangioleiomyomatosis?
Sirolimus (immunosuppressive)
## Footnote
Sirolimus is used to manage symptoms and progression of the disease.
262
What is associated with decreased chest wall compliance in aging?
Decreased elastic recoil
## Footnote
This results in an increased residual volume (RV) and decreased vital capacity (VC).
263
How do geriatric patients breathe in terms of lung volumes?
At higher lung volumes with increased functional residual capacity (FRC)
## Footnote
This adaptation occurs due to age-related changes in respiratory mechanics.
264
What physical changes contribute to decreased diaphragm efficiency in elderly patients?
Kyphosis and increased anteroposterior (AP) diameter of the chest
## Footnote
These structural changes affect the mechanics of breathing.
265
What happens to FEV1 and FVC as a person ages?
Both FEV1 and FVC decline
## Footnote
This decline reflects the overall decrease in lung function associated with aging.
266
Fill in the blank: Aging leads to increased _______ and decreased _______.
RV, VC
## Footnote
RV stands for residual volume, and VC stands for vital capacity.
267
What are some deformities of the thoracic structures?
Ankylosing spondylitis, flail chest, scoliosis, kyphosis
## Footnote
These conditions can affect the mechanics of breathing.
268
What effect do thoracic deformities have on the work of breathing?
Increased work of breathing due to abnormal mechanics and increased airway resistance
## Footnote
This occurs as a result of decreased lung volumes.
269
How does poor ability to cough affect respiratory health?
Leads to recurrent pulmonary infections
## Footnote
Effective coughing is crucial for clearing secretions and preventing infections.
270
What are the two types of costovertebral skeletal deformities?
Scoliosis and kyphosis
271
What condition may present in combination with scoliosis and kyphosis?
Kyphoscoliosis
272
What severe effect can kyphoscoliosis lead to?
Severe restrictive impaired lung function
273
When do costovertebral skeletal deformities commonly begin?
Late childhood/early adolescence
274
During what periods may costovertebral skeletal deformities progress?
Periods of rapid skeletal growth
275
What are the effects of costovertebral skeletal deformities on lung function?
Decreased ventilatory capacity & increased work of breathing
276
How does the severity of respiratory compromise correlate?
It correlates with the degree of spinal curvature
277
What is Pectus carinatum commonly known as?
Pigeon chest
## Footnote
Pectus carinatum is characterized by the outward projection of the sternum and ribs.
278
What is the cause of Pectus carinatum?
Unknown, but it does run in families
## Footnote
This condition is usually more of a cosmetic concern.
279
What symptoms can Pectus carinatum cause?
Respiratory symptoms or asthma
## Footnote
Although primarily cosmetic, it may lead to functional issues.
280
What can multiple rib fractures produce?
Flail chest
## Footnote
This occurs especially when fractures are in a parallel vertical orientation.
281
What is a characteristic movement associated with flail chest?
Paradoxical inward movement of the unstable portion of the thoracic rib cage
## Footnote
This occurs during breathing.
282
What are common symptoms of flail chest?
Pain, increased work of breathing, inability to cough, and atelectasis
## Footnote
These symptoms indicate compromised respiratory function.
283
How do lung contusions affect the chest wall?
Reduce chest wall compliance and FRC
## Footnote
FRC stands for Functional Residual Capacity.
284
What is the treatment for flail chest?
Positive pressure ventilation and stabilization
## Footnote
These interventions help manage respiratory distress and stabilize the chest wall.
285
What is pleural effusion?
Fluid (blood, serous fluid, pus, lipids) in pleural space
## Footnote
Pleural effusion can be diagnosed using imaging techniques.
286
How is pleural effusion diagnosed?
CXR, CT, or bedside US (preferred)
## Footnote
These imaging techniques help visualize fluid accumulation in the pleural space.
287
What is pneumothorax?
Gas in the pleural space
## Footnote
Pneumothorax can lead to serious respiratory issues if not managed properly.
288
Who is most commonly affected by idiopathic spontaneous pneumothorax?
Tall, thin men aged 20-40
## Footnote
This condition is often associated with rupture of apical subpleural blebs.
289
What is tension pneumothorax?
A medical emergency that develops when gas enters the pleural space during inspiration and can't escape during exhalation
## Footnote
Tension pneumothorax can lead to severe respiratory distress and cardiovascular collapse.
290
What are the symptoms of tension pneumothorax?
* Respiratory distress
* Tachypnea
* Shortness of breath (SOB)
* Hypoxia
* Pleuritic chest pain
* Tachycardia
* Hypotension (HoTN)
## Footnote
These symptoms result from compromised respiratory function and reduced venous return to the heart.
291
What physical finding may indicate pneumothorax?
Trachea may be deviated away from pneumothorax
## Footnote
This deviation occurs due to increased pressure in the pleural space.
292
What changes in breath sounds are associated with pneumothorax?
Decreased or absent breath sounds on the side of pneumothorax
## Footnote
This is due to the presence of gas in the pleural space obstructing normal airflow.
293
What happens to airway pressures and tidal volume if the patient is on a ventilator with pneumothorax?
Increased airway pressures and decreased tidal volume
## Footnote
This reflects the impaired lung mechanics due to the presence of gas in the pleural space.
294
What is the treatment for pneumothorax?
Immediate evacuation through a needle or small-bore catheter placed into the second anterior intercostal space
## Footnote
This procedure aims to relieve pressure in the pleural space and restore normal respiratory function.
295
What condition may follow hemothorax, empyema, or surgical pleurodesis?
Pleural fibrosis
## Footnote
Pleural fibrosis is a thickening of the pleura that can occur as a complication of various conditions.
296
What surgical procedure is considered if pleural fibrosis is symptomatic?
Surgical decortication
## Footnote
This procedure involves removing the thick fibrous pleura to alleviate symptoms.
297
What is acute mediastinitis commonly caused by?
Bacterial contamination after esophageal perforation
## Footnote
This condition can lead to serious complications if not treated promptly.
298
What are the symptoms of acute mediastinitis?
Chest pain & fever
## Footnote
These symptoms indicate inflammation and possible infection in the mediastinum.
299
What is the treatment for acute mediastinitis?
Broad-spectrum antibiotics & surgical drainage
## Footnote
This dual approach is necessary to manage infection and relieve pressure.
300
What are the most common types of anterior mediastinal masses?
Thymomas, germ cell tumors, lymphomas, intrathoracic thyroid tissue, & parathyroid lesions
## Footnote
Thymomas account for approximately 20% of anterior mediastinal masses.
301
What types of masses are found in the middle mediastinum?
Tracheal masses, bronchogenic and pericardial cysts, enlarged lymph nodes, & proximal aortic disease
## Footnote
Proximal aortic disease may include conditions like aneurysms or dissections.
302
What types of tumors and conditions are associated with posterior mediastinal masses?
Neurogenic tumors and cysts, meningoceles, lymphomas, descending aortic aneurysms, and esophageal neoplasms
## Footnote
These masses can lead to various symptoms depending on their size and location.
303
What are common treatments for a mediastinal mass?
Surgery, radiation, chemotherapy, or surveillance
## Footnote
The treatment approach depends on the underlying pathology.
304
What preoperative assessments are necessary for a mediastinal mass?
Measurement of a flow-volume loop, chest imaging, and assessing for airway compression
## Footnote
These assessments help determine the extent of the mass and its effects on the airway.
305
What imaging technique can establish the size of a mediastinal mass?
CT (Computed Tomography)
## Footnote
CT scans provide detailed images that help assess the mass size and degree of compression.
306
What is the role of fiberoptic bronchoscopy in the evaluation of a mediastinal mass?
To evaluate the degree of airway obstruction
## Footnote
This procedure allows direct visualization of the airway and assessment of any obstructions.
307
When should preoperative radiation be considered for a mediastinal mass?
Whenever possible to decrease its size
## Footnote
Reducing the mass size can improve surgical outcomes and reduce complications.
308
What technique is preferred for symptomatic patients requiring a diagnostic tissue biopsy?
LA (Local Anesthetic) technique
## Footnote
This technique minimizes discomfort and allows for tissue sampling in a less invasive manner.
309
What is Jeune syndrome?
Asphyxiating thoracic dystrophy associated with skeletal dysplasia and multiorgan dysfunction
## Footnote
Jeune syndrome features include cysts in the kidney, pancreas, and liver, retinal abnormalities, short ribs, short limbs, narrow thorax, and polydactyly.
310
What is a key characteristic of Fibrodysplasia ossificans?
Genetic variation in bone morphogenetic protein (BMP)
## Footnote
This condition leads to abnormal bone formation in muscles and connective tissues.
311
What is Poland syndrome?
Partial or complete absence of pectoral muscles, commonly affecting one side
## Footnote
It may also cause paradoxical respiratory motion due to the absence of multiple ribs.
312
Fill in the blank: Jeune syndrome is characterized by _______.
skeletal dysplasia and multiorgan dysfunction
313
True or False: Poland syndrome can affect both sides of the body equally.
False
