Resp Flashcards

(235 cards)

0
Q

What is charles’s law, what units are required

A

Pressure is directly proportional to temperature

Kelvin

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1
Q

What is boyles law?

A

Pressure is indirectly proportional to volume of a fixed amount of gas

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2
Q

What is the universal gas law?

What is its significance to drs?

A

Boyles and charles combined
Pressure x volume = universal gas constant x temperature
Any testing done outside of the body will generate different results of pressure as temperature changes

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3
Q

What is daltons law?

A

Each gas exerts its own pressure as if no other gases were present which is the same fraction of the total mix pressure as the fraction of the volume the gas.

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4
Q

How can water interact with gasses?

A

Evaporation of water

Dissolving of gas

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5
Q

What effect does evaporation have on inhaled gasses?

A

Water evapourates creating a fixed saturated vapour pressure at a given temperature (6.28kPa in the body) this is always exerted no matter the total pressure so is proportionally more important if total pressure falls

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6
Q

What is the tension of a gas in water? What does it equal at equilibrium?

A

A measure of how readily a gas molecule will leave the liquid
Partial pressure

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7
Q

How is the amount of gas in a liquid calculated?

A

Content = solubility x tension

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8
Q

What is the effect on gases binding to molecules within a liquid on amount and tension?

A

Tension remains the same but amount goes up

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9
Q

In blood plasma what is the oxygen tension, what amount is dissolved in plasma at that tension given oxygens low solubility? How much is carried in whole blood? Why?

A

13.3kPa gives a dissolved content of 0.13mmol/L

Total blood has 8.93mmol/L due to haemoglobin binding

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10
Q

If an abg shows a pO2 of 13.3 is the patient definitely adequately oxygenated?

A

No - there could be a haemoglobin deficiency - anaemia

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11
Q

What is the partial pressure of oxygen in the atmosphere? What about alveolar air? Why the drop?

A

21.1kpa
13.3kpa
Oxygen is being removed and co2 and h2o added

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12
Q

What is the order of the airways?

A
Trachea
Primary bronchi
Secondary bronchi
Bronchioles 
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveoli
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13
Q

What causes the alteration in nostril side during breathing?

A

Swelling of the venous plexuses in the lamina propria

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14
Q

What is the laryngeal epithelium?

A

Psudostratified ciliated columnar epithelium with mucous glands for the most part
Stratified squamous covering the vocal ligaments and the vocalis muscle

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15
Q

What is the change in epithelium from trachea to alveoli?

A

Psuedostratified ciliated (trachea, proximal bronchi)
Simple columnar ciliated (distal bronchi, proximal bronchioles)
Simple cuboidal ciliated (terminal bronchioles)

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16
Q

What changes occur to the secretory cells in the lower airways? Where?

A

In terminal bronchioles goblet cells are replaced with clara cells. In respiratory bronchioles clara cells are the predominant cell type.

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17
Q

What are the replacement for goblet cells in the lower airway? What do they produce?

A

Clara cells

Surfactant lipoproteins to prevent walls adhering in expiration

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18
Q

Where is bronchiole smooth muscle found?

A

Between the lamina propria and submucosa

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19
Q

What keeps the small airways open during expiration?

A

Direct pull from elasticity from neighbouring alveoli

Air pressure from the lumen exceeding that of the pleura due to elastic recoil of the alveoli in forced expiration

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20
Q

How does mucus secretion differ from bronchi to bronchioles?

A

Bronchi - mucus from goblet cells and submucosal glands

Bronchioles - no submucosal glands and goblet cells replaced with clara cells distally

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21
Q

Where do alveoli arise in the airways?

A

Other alveoli
Alveolar sacs
Alveolar ducts
Respiratory bronchioles

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22
Q

What are the cell types in the alveoli? What do they do?

A

Type 1 pneumocyte - squamous type that provides. Gas exchange surface
Type 2 pneumocyte - cuboidal type that secretes surfactant
Alveolar macrophages.

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23
Q

Where are the lungs by surface markings?

A

Apex 3cm above medial 1/3rd of pleural cavity
Nearly meet at mid sternal line at 2nd rib
Descend together to the 4th rib
Left moves to left sternal before descending to 6, right decends straight to 6
Both descend to 8 (pleura) / 6 (lung) at MCL
Both descend to 10 p 8 l at MAL
Both descend to 12 p 10 l at medial scapular boder

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24
What are the two fissures of the right lung? | What are their surface markings?
Oblique T2 to 6th costal cartilage | Horizontal 4th rib at mid axillary line to anterior edge of lung
25
Where does the manubrium join the body of the sternum?
Sternal angle of louis at level of second costal cartilage
26
How are the ribs classified?
1-7 true 8-10 false 11-12 floating
27
Which ribs are typical? What are landmarks on their structure?
3-9 Two articular facets on head to articulate with body of vertebra or spine and vertebra above (i.e. 3rd rib with T2 and T3) One articular facet to articulate with the transverse process of the vertebra An inferior costal groove for vessels and nerves
28
Which ribs only have one facet on their head?
1,10,11,12
29
What makes rib 2 atypical?
Poorly marked costal groove
30
When the ribs elevate how does the shape of the chest change?
Upper ribs cause increase in sagittal diameter and lower ribs transverse diameter
31
What are the different intercostal muscles? Where are they and which way do they run?
External - costoverterbral junction to start of costal cartliage, runs down and anteriorly Internal - sternal edge to just before costoverterbral junction, runs down and posteriorly Innermost - only found laterally, run as with the internals
32
What muscles are used in normal inspiration and expiration?
Insp - diaphragm and external intercostal | Exp - none
33
What muscles are used in forced inspiration?
Sternocleidomastoid Scalenes Pectoralis minor Serratus anterior
34
Which muscles are used in forced expiraiton?
Internal and innermost intercostals Rectus abdomins External and internal obliques Transvers abdominus
35
What is the order superior to inferior, of the contents of the costal groove? What about those vessels running on the superior surface?
Vein Artery Nerve Reversed
36
Where do the intercostal nerves arise? Where do they run?
Anterior rami of t1-12 | Between the internal and innermost intercostals
37
Where do the intercostal arteries arrise?
Anterior branch from internal thoracic | Posterior branch from thoracic aorta
38
Where do the intercostal veins drain?
Anteriorly to the internal thoracic vein | Posteriorly to the azygos system (azygos vein on the right, hemizygos and accessory azygos on left)
39
What are the levels of the openings through the diaphragm?
Vena cava t8 Oesophagus t10 Aortic hiatus t12
40
What does the phrenic nerve supply?
``` Sensation of the Pericardium Mediastinal parietal pleura Diaphragmatic parietal pleura Both sides of the diaphragm (except the margins supplied by the intercostal nerve) ``` Motor Diaphragm
41
What are the various regions of the parietal pleura?
Cervical Mediastinal Costal Diaphragmatic
42
What are the functions of the serous fluid?
Allows sliding of the pleura | Creates the pleural seal
43
At what level is the carina?
t4/t5
44
Which bronchi is more susceptable to obstruction, why?
Right | Shorter, wider, more verticle
45
What follows the main bronchi?
Lobar bronchi | Segmental bronchi
46
What do segmental bronchi supply? What is special about this?
A bronchopulmonary segment | Each has its own bronchi, pulmonary artery and pulmonary vein. Thus can be isolated and surgically removed
47
What are the three surfaces of the lung?
Costal Mediasteinal Diaphragmatic
48
What is the equivalent of the middle lobe in the left?
The lingula
49
How can the left and right hilum be distinguished?
Right - arteries are anterior to the bronchus Left - arteries superior to bronchus RALS
50
What is the lymphatic drainage of the lungs?
Hiliar nodes Trachobronchial nodes (right and lower left up the right, upper left up the left) Bronchiomediasteinal trunk to subclavian veins
51
What structures are associated with the hilum besides the obvious?
Phrenic nerve anteriorly Left recurrent laryngeal nerve superiorly Aorta on the left Svc and azygos on the right
52
To what level do the bronchial arteries provide oxygen? | Where does the rest get o2 and nutrients from?
Terminal bronchioles | Gas exchange and pulmonary arteries for nutrients
53
How is the mediasteinum divided? | What is in each bit?
Anterior - between sternum and pericaridum Middle - between anterior and posterior! Fibrous pericardial contents Posterior - between vertebral bodies and pericardium Superior - above line from sternal angle and t4
54
What is the pO2 and pCO2 of pulmonary arteriolar blood?
6 | 6.5 kPa
55
What influences the rate of diffusion across the alveolar membrane?
Area Gradient Resistance (nature of barrier and gas)
56
What 6 layers must an oxygen molecule travel from mid alveoli to inside a rbc?
``` Through the gas Alveolar cells Intersitial fluid Endothelial cells Plasma Red cell membrane ```
57
Which gas moves through gas easier?
Oxygen - it has a lower molecular weight
58
What gas diffuses faster through liquids (including phospholipid bilayer)? What is the result of this?
co2 | As a result a problem with diffusion nearly always selectively effects O2
59
Why do small changes in diffusion resistance not affect concentration of blood gasses in the pulmonary veins?
Because blood passes next to alveoli for 1s but only takes 0.5s to reach equilibrium thus there is plenty of leaway
60
How does the body keep the concentrations of alveolar gasses constant during respiration?
Pulmonary ventilation only reaches the terminal bronchioles. From there gas diffuses into and out of the alveoli not fluctuating with the respiratory cycle. This is alveolar ventilation
61
What are the lung volumes?
Inspiratory reserve volume - 3.3L Tidal volume - 0.5L Expiratory reserve volume - 1.2L Residual volume - 0.8L
62
What are the lung capacities?
Vital capacity - 5L Inspiratory capacity - 3.8L Functional residual capacity - 2L Total capacity 5.8L
63
Why do we measure lung capacities?
Volumes change with patterns of breathing so are not fixed for an individual. As a result tests would vary time to time (poor consistency) Capacities are all measured from fixed points in the cycle - max inspiration, max expiration, end of passive expiration
64
What is the term for the volume of air moved in a breath times the respiratory rate? What is it typically?
Pulmonary ventilation rate | 16x500ml = 8000ml/min
65
What are the dead spaces? Typical values?
Serial - conducting airway volume (0.15L Distributive - non perfused alveoli volume (0.02L) Physiological - serial + distributive (0.17L)
66
What is alveolar ventilation rate? | Typical values
``` AVR = pulmonary ventilation rate - dead space ventilation rate AVR = (16x500)-(16x170) AVR = 8000 - 2720 = 5280 ```
67
What is the consequence of dead space in the lungs?
Rapid breathing is less efficient as dead space becomes proportionately more important.
68
What is the term for the connection between the two layers of pleura that means the lungs pull out with chest expansion?
Pleural seal
69
Why do we expire by relaxing after inspiration? Why does it stop?
At the end of inspiration we relax our muscles. Consequently the inward elastic pull of the lungs becomes greater than the outward pull of diaphragm and chest so they are pulled inwards. At the end of passive expiration the inward elastic pull equals the outward recoil of the chest and diaphragm so there is no movement.
70
What happens during forced expiration?
Muscles augment the inwards elastic pull of the lungs and pleural pressure exceeds atmospheric pressure (the only time this occurs) forcing the lungs to contract.
71
What is lung compliance?
A measure of the volume change per unit pressure change. A highly compliant lung has big volume changes for small pressure changes, a poorly compliant lung has the reverse.
72
What causes the elastic recoil of the lungs?
Elastin in the walls/interstitium | Surface tension
73
What is surface tension?
The tendency of a liquid to contract to its minimal volume as molecules on the surface are being pulled into the centre (attractive forces with other water molecules but not the air - thus pulled in)
74
Why do small alveoli tend towards collapse? How does surfactant prevent alveolar collapse?
Pressure required to keep alveoli open = (2x surface tension) / r Thus small alveoli require a larger pressure to stay open than big Surfactant reduces surface tension more when compact, thus reduces surface tension more in small alveoli so the pressure needed to stay open reduces more in these.
75
Functions of surfactant
Stopping alveolar collapse | Reducing compliance
76
Diseases with high compliance
Emphysema
77
Diseases with low compliance
Fibrosis | Respiratory distress syndrome of the newborn
78
Will FRC increase or decrease in a disease which increases compliance like emphysema? Why?
It will increase The point at which FRC is reached is the point when inward pull of the lung is matched to outwards pull of the chest. As lung compliance has increased then at this volume inward pull will be less. For the forces to balance the volume must be greater - the new equilibrium is at a greater volume!
79
What will be the effect on FRC of a disease that decreases lung compliance like fibrosis?
Decreased frc. Frc depends on an equilibrium between inward pull of the lung and outward pull of the chest wall. At a healthy FRC the stiff lung will be generating greater force than the outward pull - as a result FRC must reduce to reach equilibrium with outward pull.
80
What is hysteresis? How does it apply to the lungs?
The energy expanded increasing surface tension when surface area is increased is not all recovered when surface area reduces. Practically this means as pressure increases on inspiration the volume will increase as it overcomes surface tension - however, on expiration for each given pressure the lung volume will be greater.
81
During inspiration order atmospheric pleural and alveolar pressures from high to low
Atmospheric Alveolar Pleural
82
During expiration order atmospheric pleural and alveolar pressures from high to low
Alveolar Atmospheric Pleural
83
During forced expiration order atmospheric pleural and alveolar pressures from high to low
Pleural Alveolar Atmospheric
84
What law is relevant to the size of alveoli and pressure?
Laplaces | Pressure = 2 ST / r
85
What law is relevant to flow through tubes?
Poiseulles Flow is directly proportional to: (Pressure gradient x radius squared x radius squared) / (viscosity x length)
86
Where is the highest resistance in the airways during normal respiration?
Trachea! Smaller airways are in parallel so their radius is actually greater!
87
Where is the highest resistance to airflow in forced expiration?
The small airways - they narrow as interpleural pressure increases
88
Why do you get airway obstruction in empysema?
On forced expiration inter-pleural pressure increases. Due to the lack of elasticity of the lungs there is less alveolar pressure. As a result the airways are compressed
89
What does spirometry show?
Inspired and expired volume with time
90
What is an issue with spirometry in determining vital capacity? What can effect both
Is a lowered value due to low max inspiration or low max expiration? Low max insp - chest wall defect, chest muscle weakness (restrictive defect) Low max exp - narrowed airways (obstructive defect)
91
How can we differentiate between restrictive and obstructive defects of the lung?
A vitalograph trace
92
What does a vitalograph trace involve? What values are derived from it?
Taking a single maximal inspiration then expiring into a spirometer as fast as possible Forced Vital Capacity (FVC) Forced Expiratory Volume in one second (FEV1)
93
What vitelograph reading would suggest an obstructive lung defect?
A FEV1 <70% of FVC
94
What suggests a restrictive defect on vitalograph?
A low FVC with a FEV1 >70% (note actual value of FEV1 will be lowered but it is the ratio that is important)
95
How can more information be gained from a vitelograph over and above fvc and fev1?
Conversion into a flow volume loop.
96
At what point of forced expiration does an individual produce PEFR?
Almost immediately as lungs are stretched so resistance is least
97
What is seen on an flow volume curve in obstructive airway disease? What is the advantage of this test over vitalograph?
A rapid decrease from maximal flow with increasing volume scooping out the curve
98
Why do we use PEFV is asthma?
Very cheap and simple to use. It is measuring large airway resistance but in severe asthma will become effected by small thus indicates a severe issue
99
How can we measure residual volume?
Breath in helium at a known concentration starting from end of passive expiration Monitor how concentration of expired helium has reduced to determine volume of air already in the lungs
100
How can we measure serial dead space?
Perform a nitrogen washout Breath pure O2 Measure percentage of nitrogen against volume on expiration Initial expiration will have no nitrogen (as large airways replaced with o2 first) Mid expiration will have increasing nitrogen from alveolar air diffusion End expiration will have normal nitrogen Draw a line midway down the curve - area to left represents serial dead space
101
How can we measure diffusion over alveoli?
Give carbon monoxide | Measure the amount on haemoglobin in blood
102
Why do we use CO to measure alveolar diffusion?
It binds fully to haemoglobin so exerts no partial pressure thus gradient is always (given concentration : 0)
103
What is a flaw with oxygen saturation measurements when considering amount of oxygen reaching the tissues?
Doesnt consider pigment concentration thus not amount of oxygen
104
What is the typical concentration (!) of o2 in pulmonary venous gas
Conc Hb = 2.2mmol/L Each Hb can hold 4 O2 thus conc O2 is 8.8mmol/L Add disolved O2 of 0.13mmol/L gives 8.93mmol/L
105
If 100% saturated blood in the lungs has a O2 concentration of 8.8mM what is the concentration in 65% saturated tissue?
0.65x8.8=5.8
106
How are active tissues adapted to get the most O2? | How much extra of the norm of 3mM drop in concentration can active tissues achieve? What does this mean?
High capillary density allowing lower pO2 with all cells still recieving sufficient H+, co2 and temp high Can double amount released to. 6mM This means that an increased O2 demand can be matched with half the increase by the CVS
107
What is the concentration of CO2 in arterial blood? How does it change in venous? What is the implication of this?
21.5mM Raises by 2mM The vast majority of CO2 in blood is nothing to do with respiration!
108
How is CO2 carried in blood? Percentages please
8% dissolved 12% as carbaminocompounds (mainly carboxyhaemoglobin) 80% reacts with water forming H+ and bicarbonate ions from carbonic acid
109
What happens to CO2 as it leaves a producing cell
Enters plasma. No CA in plasma so little reaction occurs Enters RBC. CA converts it to carbonic acid Carbonic acid to H and bicarbonate ion H binds to Hb (HbH) causing stabilisation of T state releasing O2 Bicarbonate ion shunted into plasma in exchange for Cl- Removal of products from RBC favours continued forward reaction
110
What is the consequence of high bicarbonate concentration in plasma?
Pushes the CO2 and Water to H and HCO3- to the left stopping the creation of H+ in the plasma
111
Why is venous pH not higher than arterial? There is more CO2 after all?
Less o2 thus H+ can bind more to Hb and thus more HCO3- in plasma Also higher caboxyhaemoglobin
112
What. Happens in the lungs to cause CO2 exhalation?
High. O2 = HbH to Hb and H H and HCO3- to CO2 and H2O CO2 breathed out
113
What is the dilemma with respiratory control?
Compensating for hypoxia alone would cause hypocapnia and vica versa. Only works if hypoxic and hypercapnia
114
How is low oxygen detected? At what level?
By peripheral chemoreceptors | At 8kPa prior to significant fall in sats
115
What feature of peripheral chemoreceptors allows them to respond to oxygen conc. changes?
Very well supplied with blood so only become hypoxic if ppO2 drops below 8kPa
116
What is the response of the body to hypoxia?
Increased resps Increased heart rate Diversion of blood to the brain
117
What can increase the sensitivity of peripheral chemoreceptors to hypoxia?
Hypovolemia - become hypoxic more easily
118
What would a biochemical profile of resp acidosis look like?
Low ph High co2 High bicarb (over several days - compensation)
119
Differentiate compensation and correction of acidosis/alkalosis
Compensation - other system trying to return ph to normal | Correction - effected system altering to oppose changes
120
What would a metabolic alkalosis look like biochemically?
High pH High bicarb High CO2
121
How would a resp alkalosis appear biochemically?
High pH Low CO2 Low bicarb
122
How would a metabolic acidosis appear biochemically?
Low ph Low bicarb Low CO2
123
Why does compensation help stabilise pH?
Because its ratios that matter not actual componenets. Circa henderson hasselbach
124
Where and how are changes in pCO2 detected?
Mainly central chemoreceptors in medulla | Respond to pH changes in CSF
125
How does change in CO2 effect CSF pH?
Co2 diffuses freely into CSF whilst bicarbonate cannont Thus acute rise in CO2 causes acidosis in CSF and increased respirations But CSF doesnt like being acidic so choroid plexuses increase import of bicarbonate normalising pH in chronic high CO2 and resps return to normal thus CO2 builds up.
126
What is type 1 resp failure? | When does it normally occur?
Low O2, normal or low CO2 | Usually from v/q mismatch or diffusion problems
127
Examples of vq mismatch resulting in type 1 resp failure
PE Pneumonia Early acute asthma
128
Why does poor perfusion of an alveoli lead to type 1 resp failure?
Alveoli still equally ventilated but more blood passing by some. Alveoli with low V/Q (not effected) has lower pO2 due to more blood passing so lower pO2 in blood. CO2 removal can be increased however. Alveoli with high V/Q (effected) cant raise pO2 as either no exchange at all if no blood, or, if some blood passing then already at maximum O2
129
Why does poor ventilation of some alveoli cause type 1 resp failure?
In alveoli with low V/Q (effected) alveolar pO2 falls and pCO2 increases. Passing blood becomes hypercapnic and hypoxic Air is diverted to healthy alveoli: In alveoli with high V/Q (not effected) blood cannot receive more O2 as already fully saturated, however, CO2 removal can increase
130
Examples of diffusion problems causing type 1 resp. Failure. How does this occur?
Fibrotic lung disease Pulmonary oedema Emphysema (early) By increasing diffusion resistance, distance or reducing surface area oxygen is primarily effected as CO2 can diffuse more easily
131
What is type 2 resp failure? | Cause?
Decreased o2 and increased CO2 Cause is ventilation failure - chest wall defect eg kyphosis or trauma - resp depression eg opiates or stroke - decreased compliance eg fibrosis - increased airway resistance eg asthma or COPD
132
How can someone with type one resp failure be acidotic?
Decreased O2 means increased anaerobic resp means lactic acid
133
Long term complications of t2rf
Hypoxic drive Resp acidosis Cor pulmonale due to pulmonary htn Increased Hb
134
Characteristics of asthma
Reversible airway obstruction Increased airway responsiveness to stimuli Airway inflammation and remodelling
135
What occurs in airway remodelling in asthma?
Increased sumbmucosa Epithelial metaplasia increasing goblet cells Epithelial damage increasing vulnerability to infection Deposition of collagen in lamina reticularis causing BM thickening Increased smooth muscle mass and responsivness
136
What causes airway remodelling in asthma?
Chronic inflammation releasing - cytokines, leukotrienes, growth factors (for repair) From inflammatory cells and epithelium
137
What is poiseuilles law? What does it mean for asthmatics?
Flow = (P x pi x r^4) / (8 x v x L) | Decrease in radius means marked decrease in flow or increase in pressure gradient to maintain flow
138
What can trigger the hyperresponsive smooth muscle in asthma?
``` Allergens (dust mites, pollen, pollution, smoke) Cold air Exercise NSAIDS Beta blockers Emotion Infection ```
139
Causes of asthma
Genetic (family risk) | Environment (hygiene hypothesis, pre/post natal smoke)
140
2 types of asthma
Atopic (other allergies, circulating IgE, +ve skin prick tests) Non-atopic (drug induced, viral induced wheeze, occupational)
141
How does asthma present?
``` Wheeze Breathless Dry cough Chest tightness Variable airflow obstruction ```
142
Diagnostic tests used in asthma
Spirometry (pre and post bronchodilator) CXR PEF Allergy testing
143
Non pharmacological management of asthma
``` Stop smoking Breast feeding Decreased exposure to allergens Fresh air Weight loss ```
144
What is copd?
A progressive non reversible ariflow obstruction that does not change markedly over several months. It is caused primerally by smoking
145
What is the pathological mechanism behind emphysema?
Destruction of terminal bronchioles and distal airspace leading to a loss of surface area and the formation of bullae (large redundant airspaces) Destruction of supporting tissue causes decreased elasticity thus collapse of airways on forced expiration and decreased recoil so hyperinflation
146
Pathological mechanism of chronic bronchitis
Chronic mucosal hypersecretion due to inflammation Chronic productive cough Remodelling, metaplasia and narrowing of the large airways
147
How is copd graded?
``` MRC score 1 not troubled 2 breathless on hurrying 3 slower than contemporaries 4 stops for breath after 100m 5 too breathless to leave house ```
148
Signs of copd
``` Pursed lip breathing Tacyponea Accessory muscle use Hyperinflation of chest Wheeze Cyanosis Heart failure Co2 retention flap ```
149
If there is a good history, what test will confirm copd? What will it show? What is the cut off for severe
Spirometry Low fev1:fvc ratio. (Severe <30%) Decreased fvc
150
Other than spirometry what tests are useful in copd? Why?
Cxr to exclude other pathology Ct if considering surgery Abg for checking for resp failure Alpha one antitrypsin test if young
151
Management of COPD
``` Stop smoking Bronchodilators Steroids Mucolytics Flu vaccine O2 if pO2 consistently below 7.3kPa Surgery Pulmonary rehabilitation ```
152
What is copd pulmonary rehabilitation
Encouraging light exercise to stop cycle of breathless, sedentary, breathless, sedentary
153
How are exacerbations of copd managed?
``` O2 Nebs Steroids Abx Aninophylline NIV ITU ```
154
Contraindications of NIV
``` Pneumothorax Gcs under 8 Facial injury Life threatening hypoxia Vomiting Agitated Excessive upper airway secretions ```
155
Why is tb on the risk in uk?
Immigration Aids Immunosuppressive meds
156
What can happen on initial tb exposure?
Containment with langerhans giant cells then granulomas with epitheloid macrophages. Adaptive response over 3-8 weeks Granuloma sealed off Usually sub clinical but can cause vague illness
157
What happens if the immune response to TB infection was inadequate? How does it present?
Primary TB with tiredness, malaise, anorexia, weight loss, fever, night sweats, wheezing, lymphadenopathy, clubbing, haemoptysis.
158
Other than direct progression causing primary tb with inadequate response how can typical symptomatic tb develop?
``` Post primary tb Contained tb remains latent then reactivated by: Immunosuppression (meds, aids) Reinfection Malnutrition Malignacy ```
159
What is the location of the initial tb infection called? What about when it spreads locally (to what tissues)?
``` Primary focus (or ghons focus) Spreads to nearby lymph nodes forming primary complex ```
160
Where can tb spread? What are the infections at different places called?
``` Pleura - effusion Meningies - meningitis Diffuse intravascular - millary Spine - potts Skin - lupus vulgaris ```
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What tests are appropriate in suspected tb? What test has a NPV of 100%?
CXR - NPV 3 x speutum ziehl neelsen stain Culture
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Treatment regime for TB with side effects
2 months of all followed by 4 of rif and iso Rifampicin - liver, red secretions Isoniazide - liver, peripheral neuropathy Pyrizinamide - liver, gout Ethanbutol - optic neuritis
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Other than treating active tb when might anti. Tb. Antibiotics be used?
Prophylaxis in patients about to undergo immunosuppression who have had tb before
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What forms of tb is the vaccine good against?
Menigeal | Milliary
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What skin test is used for tb? What might cause problems with it?
Mantoux - if infected then stimulates inflammation of the skin. Inflammation
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When would you consider directly observing tb meds. Being taken?
``` Homeless Alcoholics Mental illness Immigrants Drug resistance ```
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What is MDR tb resistant too?
Rifampicin and isoniazide
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What is externsivly drug resistant tb resistant too?
Rifampicin Isoniozid Quinolones And anther second line
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How is lung cancer incidence changing?
Falling in men and rising in women mimicing smoking habits 15 years delayed
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What percentage of lung cancer patients are due to cancer?
90% in males 80% in females | Many of the remaining due to passive
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What are causes of lung cancer other than smoking
``` Copd Assbestos Radon Occupational Genetic ```
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Symptoms from local tumour effects of lung cancer
``` Cough Dysponea Wheeze Haemoptysis Chest pain Weith loss Lethargy ```
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Symptoms from regional lung cancer mets?
Svc obstruction Horse voice Dysponea Dysphagia
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Paraneoplastic symptoms of lung cancer
``` Hypercalcemia SIADH Cushings Anaemia Clubbing Encephalopathy ```
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Where does lung ca commonly metastisise?
Bone | Brain
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What are the histological differentiations of lung cancer? How do they appear?
Small cell carcinoma (small cells, little cytoplasm, necrosis) Squamous cell carcinoma (angulated, keritinised, desmosome bridges) Adenocarcinoma (glandular) Large cell carcinoma (large rounded cells)
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Which type of lung cancer is most common?
Squamous cell carcinoma
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What lung cancer type isnt usually aminiable to surgery?
Small cell?
179
Which lung cancer type may be curable with chemo?
Small cell
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How can radiotherapy be used in lung cancer?
Alone or in combo with chemo
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Diagnositic techniques used in lung cancer
``` Chest xray Ct Mri Pet ct Isotope bone scans Bronchoscopy Endobronchial ultrasound with biopsy ```
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Prognosis of lung cancer | Why is it like this
10-15% 10 yr survival Tends to present late in high stages Caught very early then 10 year survival is 40%
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Other than late presentation why might lung cancer survival be so poor?
Professional nihilism Variable standard of care Lack of public pressure for campaign Presents to Gp not specialist
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What is the. Average survival post dx of untreated small cell lung cancer? What if chemo is given?
3 months | 1 year
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Examples of types of urti? What is the usual cause?
``` Pharyngitis Rhinitis Tracheitis Epiglottitis Laryngitis Sinusitis ``` Viral
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Usual cause of pneumonia? What other LRTIs are possible?
Bacterial Bronchiolitis Bronchitis
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Normal cause of bronchiolitis?
Respiratory syncytial virus
188
In what ways can pneumonia be classified?
Community vs hospital Acute vs subacute vs chronic Bacteria vs virus vs fungi Lobar vs broncho vs interstitial
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Typical bacteria that cause community pneumonia
Haemophillus influenza Streptococcus pneumonia Kleibesella pneumonia
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Who is more at risk of community aquired haemophillus influenza infection?
Copd
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Who is more at risk of community aquired strep pneumonia pneumonia?
Elderly
192
Common bacteria for hospital acquired pneumonia
Staphylococcus aureus inc MRSA Psuedomonas aeruginosa Gram neg enteric bacteria
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What raises risk of hospital acquired staph aureus pneumonia?
Post viral infection
194
Common viral causes of pneumonia
Influenza Parainfluenza Respiratory syncytial virus
195
Atypical causes of pneumonia with risk factors
Legionella (air con / travel) Chlamydia (birds) Mycoplasma (young people)
196
Opportunistic causes of pneumonia?
``` Candida Aspergillus Pneumocystis jirovecii Cytomegalovirus HSV ```
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What is the most common cause of lobar pneumonia?
Streptococcus pneumonia
198
What is the most common causes of bronchopneumonia?
Streptococcus pneumonia Haemophillus influenza Staph aureus Coliforms
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On investigation of a pneumonia multiple organisms are cultured? What could be the cause? What sort of pneumonia is it likely to be?
Aspiration | Bronchopneumonia
200
How can severity of pneumonia be assessed?
C - confused (AMT 7 R - resps >30 B - BP <90 65
201
How is mild to moderate pneumonia treated prior to cultures return?
Amoxicillin
202
How is severe pneumonia treated prior to culture?
Coamoxiclav
203
Indications for pneumonia onto ICU
Resp failure Progressive acidosis Shock Hypercapnia
204
Complications of pneumonia in the long term
Fibrous scarring Abcess Bronchiectasis Empyema
205
Risk factors for acquiring pneumonia in hospital
``` Itu Ventilated Suppressed immunity Atelectasis (post chest injury/surgery) Immobile ```
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Signs of pneumonia
Wheeze Crackles Dull percussion Low resonance
207
Symptoms of pneumonia
``` Fever Chills Sweats Productive cough Dysponea Pleuritic chest pains ```
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What tests are performed in pneumonia?
Speutum culture and gram stain Cxr Fbc, urea, lft, crp
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What special tests are performed in legionella pneumonia?
Legionella antibodies in urine
210
Things to check at the start of a chest xray
Field of view (1st rib to costophrenic angle) Penetration (vertebra behind heart) Rotation (spinous processes in midline between clavicles) Volume (on inspiration with 5-7 ribs visible) No artefact Demographics!
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What should you look for assessing airway on a CXR.
Trachea central | Clear angle at hila with left higher than right
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What should you look for on breathing on a cxr?
Lungs equal both sides No visible pleural space No consolidation or masses
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What should you look for on circulation onCXR?
Heart less than 50% of chest diameter | Aortic notch present
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What should you. Look for on diaphragm/dem bones on CXR
No free gas Not flattened No bony fractures
215
What is sail sign? What else might indicate this pathology?
Double heart boder due to left lower lobe collapse Also presents with lowered pressure causing mediastinal shift towards pathology and elevation of ipsolateral hemidiaphragm
216
What can cause consolidation on a cxr?
Pus Blood Fluid Cells
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What are the overall efffects of interstitial lung disease?
Loss of compliance Increased alveoli to capillary diffusion distance Destruction of alveoli and capillaries causing v/q mismatch
218
Signs and symptoms of interstital lung disease
``` Gradual onset sob Dry cough Diffuse crackles Clubbing Cynosis Right heart failure (cor pulmonale) Tachycardia and tachyponea ```
219
How does a ct show interstitial lung disease
Honeycombing
220
Hw does a cxr show interstitial lung disease?
Increased lung markings | Blurred boarders
221
Causes od interstitial lung disease
``` Idiopathic Treatment related Connective tissue disease Immunological Occupational ```
222
What are the two commonest causes of interstitial lung disease?
Idiopathic | Immunological
223
Examples of immunological causes of interstitial lung disease
Sarcoidosis | Hypersensitivity pneumonitis
224
Examples of connective tissue diseases causing interstitial lung disease
Sle | Ra
225
Examples of occupational exposures leading to interstitial lung disease
Asbestosis Coal workers pneumoconiosis Silicosis
226
Examples of treatments that cause interstitial lung disease
Amiodarone Methotrexate Bleomycin Radiation therapy
227
How does the visceral pleura receive its blood supply?
Via the bronchials
228
How does the parietal pleura receive its blood supply
Costal - intercostals Mediastinal - bronchials Apex - subclavian
229
What can cause increased plural fluid production?
High hydrostatic pressure (eg chf) Increased permeability (eg sepsis) Decreased oncotic pressure (eg liver failure) Increased Interstitial fluid
230
What can cause decreased pleural fluid absorption?
Lymph blockage | Elevated venous pressure
231
Other than pleural fluid what else can cause a pleural effusion?
Empyema (pus) Haemothorax (blood) Chylothorax (lymph)
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What are complications of pleural effusion?
Fistula with bronchi or skin Trapped lung Functional restriction Fibrothorax
233
Give some examples of congenital chest wall disease
Scoliosis and kyphosis Pectus carinatum Pectus excavatum
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Other than congenital what sorts of chest wall diseases are there?
Traumatic | Iatrogenic (eg post tb surgery