Respiratory Flashcards
(568 cards)
1
Q
How many airway divisions are there?
A
23
2
Q
Which are the conducting airway divisions?
A
1-16
3
Q
Which airway divisions are the respiratory zone?
A
17-23
4
Q
Define partial pressure of a gas
A
The individual pressure exerted independently by that gas within a mixture. (Each pressure is equal to the pressure it would exert if it were the only gas present)
5
Q
What determines how much of a gas dissolves in a liquid?
A
The amount of gas dissolved in a liquid is proportional to the pressure of the gas in contact with the liquid
6
Q
How is partial pressure in alveolar air different to atmospheric air?
A
More water vapour Less O2 (constantly leaving) More CO2 (constantly entering)
7
Q
What is the pO2 in capillary blood?
A
13.3KPa
8
Q
What is the pCO2 in capillary blood?
A
5.3KPa
9
Q
What is the pO2 in interstitial fluid?
A
6KPa
10
Q
What is the pCO2 in interstitial fluid?
A
6KPa
11
Q
What lines the conducting portion of the respiratory tract?
A
Mucous membrane (mucus secreting cells)
12
Q
Where in the respiratory system are serous membranes found?
A
Lining the pleural sacs that envelope each lung
13
Q
What are the smallest branches of the conducting portion of the conducting system called?
A
Terminal bronchioles
14
Q
What histiological cells are in the majority of the conducting portion of the respiratory system?
A
Pseudostratified epithelium with cilia and goblet cells
15
Q
What hisiological cells are in the terminal bronchioles, and what portion of the respiratory system are they a part of?
A
Simple columnar epithelium with cilia and Clara cells (but no goblet cells)
Conducting portion
16
Q
What type of cells are in the respiratory portion of the respiratory system, minus alveoli?
A
Simple cuboidal epithelium with Clara cells. Few sparse cilia.
(Respiratory bronchioles and alveolar ducts)
17
Q
What type of cells are in the alveoli?
A
Simple squamous, types 1 & 2
18
Q
How do Venus plexuses avoid overdrying?
A
Swell every 20-30mins, alternating airflow thus preventing over drying. Patence maintained by surrounding cartilage/bone.
19
Q
What is the olfactory system?
A
Your sense of smell
20
Q
What does the olfactory system look like histiologically?
A
Particularly thick pseudostratified columnar epithelium, without goblet cells.
21
Q
Where is the olfactory system located?
A
In the posterior, superior regions of each nasal fossa
22
Q
Describe olfactory cells
A
Bipolar neurones. One dendrite extends to surface to form a swelling from which non-motile cilia extend parallel to surface. These increase surface are and respond to odours
23
Q
What cells line the vocal cords?
A
Stratified squamous epithelium
24
Q
What do the vocal cords consist of?
A
A vocal ligament (elastic fibre bundle front to back)
A vocalis muscle (skeletal muscle)
25
Other than talking, what other functions do the vocal cords have?
Help prevent foreign objects from reaching the lungs, close to build up pressure when coughing is required.
26
What dimensions is the trachea?
10cm long
| 2.5cm wide
27
Describe the histology of the primary bronchi
Hisiologically similar to the trachea, but their cartilage rings/spiral muscle completely encircles the lumen
28
Describe the histology of the secondary/tertiary bronchi
Histiologically similar to primary bronchi, but cartilage arranged as irregular crescent plates/islands rather than rings
29
What is a bronchiole?
Has a diameter of 1mm or less
30
What do Clara cells secrete, and what does it do?
Lipoprotein, which prevents walls sticking together during expiration.
Also Clara fell Protein CC16 (a measurable marker for disease)
31
What is a terminal bronchiole?
Has a diameter of less than 0.5mm
| The smallest conducting portion, no goblet cells to prevent 'drowning' in own mucous
32
What can an alveolus open up into?
Respiratory bronchiole
Alveolar duct
Alveolar sac
Another alveolus (via an alveolar pour)
33
Give 4 features of alveolar walls
Have abundant capillaries
Are supported by a basketwork of elastic and reticular fibres
Have a covering composed chiefly of type 1 pneumocytes
Have a scattering of type 11 pneumocytes
34
Other than pneumocytes, what other cell may be in alveoli?
Macrophages, to phagocytise particles
35
What are the name of the 4 facial sinuses?
Frontal
Ethmoid
Maxillary
Sphenoid
36
What are the 3 different types of rib, and which ones are they?
True - connect directly to sternum 1-7
False - connect to sternum via cartilage 8-10
Floating - don't connect to sternum at all 11-12
37
What are the 2 connections via which the ribs connect to the vertebrae?
Superior costotransverse ligament
Costotransverse joint
Joint with ventral body
38
What are the 3 movements of the chest wall?
'Bucket handle' - up/down of ribs
'Pump handle' - anterior/posterior motion
Diaphragm moves down 1 1/2 intercostal spaces
39
In which way do the Intercostal muscles pull the ribs?
External - pulls ribs up (1st rib is anchored). inhalation
| Internal and innermost pull ribs down. Exhalation
40
In which order is the intercostal neurovascular bundle arranged?
Vein
Artery
Nerve
Top--->Bottom
41
In which direction do the external intercostal muscle fibres run?
'Hands in pocket' down and medially
42
In which way do the innermost and internal intercostal muscles run?
Perpendicular to the external
43
Where abouts in the intercostal space does the neurovascular bundle run?
Along the bottom of each rib/top of each space
| Between the internal and innermost muscles
44
At what level does the vena cava go through the diaphragm?
T8
45
At what level does the oesophagus go through the diaphragm?
T10
46
At what level does the aortic hiatus go through the diaphragm?
T12
47
What is the diaphragm comprised of?
Dome shaped peripheral muscle and central tendon
48
What does the azygous system do?
Collection of veins which collect blood from intercostal spaces taking it to the superior vena cava
49
Which way do the lungs themselves pull?
In and up
50
Which way does the thoracic cavity itself pull?
Out
51
What way does the passive stretch of the diaphragm pull?
Down
52
When respiratory muscles relax, what happens?
Expiration
53
When respiratory muscles contract in resting breathing, what happens?
Inspiration
54
What are the 4 stages of the respiratory cycle?
1. Inhalation
2. Rest
3. Expiration
4. Pause
55
When is forced expiration required?
Exercise, coughing, singing
56
What brings about forced expiration?
Contraction of internal intercostal muscles/abdominal muscles
57
How many lobes has the left lung got? What are they called?
2
| Upper and lower
58
How many lobes has the right lung got? What are they called?
3
| Upper, middle and lower
59
How many fissures has the left lung got? What are they called?
1
| Oblique fissure
60
How many fissures has the right lung got? What are they called?
2
| Oblique fissure, horizontal fissure
61
What vessels has each lung got at its hilum?
```
Principal bronchus
Pulmonary artery
2 pulmonary veins
Bronchial vessels
Pulmonary plexus (nerves)
Lymphatics
```
62
What is pneumothorax?
The integrity of the pleural seal is broken, lungs tend to collapse
63
What vasculature supplies the parietal pleura?
Intercostal arteries/veins
64
What vasculature supplies the visceral pleura?
Bronchial arteries/veins
65
What are the 3 surfaces of each lung?
Costal, diaphragmatic, mediastinal
66
What are the sympathetic efferents of the lungs?
Bronchodilator, vasoconstrictor
67
What are the two lymphatic plexuses to the lungs?
Superficial sub-pleural lymphatic plexus
| Deep bronchopulmonary lymphatic plexus
68
Where is the superficial sub-pleural lymphatic plexus of the lungs found?
Deep in visceral pleura.
69
What does the superficial sub-pleural lymphatic plexus drain?
Drains hilar lymph nodes and lung parenchyma and visceral pleura
70
Where does the deep bronchopulmonary lymphatic plexus drain to?
Hilar nodes
71
What is compliance?
The 'stretchiness' of the lungs
Volume rover unit pressure change
(Higher compliance - easier to stretch)
72
What does the pleural seal do?
Holds outer surface of the lungs to inner surface of the chest wall, ensuring the 2 move together
73
When are the elastic forces of lung and chest wall balanced?
Functional residual capacity
| Lung volume at the end of resting expiration
74
What is elastic recoil inversely proportional to?
Compliance of lung
75
What muscles may you additionally use for forced expiration?
Serratus anterior
Pectoralis maj
Sternocleidomastoid
Scalene
76
What are the elastic properties of the lung due to?
Elastic tissue
| Surface tension of alveolar fluid
77
What does surfactant do?
Reduces surface tension by disrupting interactions between surface molecules (breaking up hydrogen bonds)
78
What is surfactant comprised of?
90% phospholipids (60% of which is phosophatidylcholine)
7-15% phosphatidyglycerol
10% protein
Surfactant protein A
79
What produces surfactant?
Type 2 pneumocytes (cuboidal)
80
What does surfactant do?
Reduces surface tension when lungs are deflated, but less so when fully inflated (little breaths easy)
81
What is Laplace law? (Pressure)
Pressure = (2xsurface tension) / radius
82
Give 3 ways surfactant aids lung function
Increases lung compliance by reducing surface tension
Stabilises lungs, preventing small alveoli collapsing into big ones
Prevents surface tension in alveoli creating suction force causing Transudation of fluid from pulmonary capillaries
83
What is respiratory distress syndrome in premature babies?
Babies are born with too little surfactant and few large alveoli
84
What is poiseuilles law? (Movement through tubes)
Resistance = pressure / rate of flow
=(8 x viscosity of fluid x length of tube) / (1 x radius)
85
What is the key point if poiseuilles law of movement through tubes?
Small tubes have high flow resistance
86
What helps compensate for the increase of resistance in the lungs as the tubes get narrower?
Each branching point increases the number of airways in parallel, this compensates for increase of resistance as air passes down
87
Where is the highest resistance in the airways?
Upper airways - trachea and larger bronchi
Each branching point increases the number of airways in parallel, this compensates for increase of resistance as air passes down
88
What happens to pressure throughout the lung?
Remains constant as surfactant equalises surface tension
89
What is flicks first law of diffusion?
Flux of molecules across a barrier is proportional to the permeability of the molecules times the surface area over which diffusion can occur times the concentration gradient
90
What is me soluble, CO2 or O2?
CO2 (~20 times more soluble)
91
What is the limiting factor of the rate of gas exchange in the lungs?
Rate of O2 diffusion
92
What compensates for slower O2 diffusion?
Larger pressure difference for O2
93
What is ficks equation for rate of diffusion?
D = (Pressure diff. x Area x Solubility) / distance x (root of molecular weight of gas)
Assume 37 degrees C
94
What are the barriers O2 must cross to get from in the alveolus to the RBC?
```
Epithelial cell of alveolus
Tissue fluid
Endothelial cell of capillary
Plasma
Red cell membrane
```
95
What is the distance between air and alveolar capillary blood?
~0.6um
| Decreases during inhalation as lung distends
96
How is inspired air different in concentrations to atmospheric air?
Saturated with water vapour as it passes along moist airways (PH2O ~6%)
Therefore O2 and N2 are slightly diluted
97
What is the normal value for partial pressure of CO2 in the alveoli?
5.3kPa
98
What is the normal value for partial pressure of O2 in the alveoli?
13.3kPa
99
CO2 reacts with water to form what?
Carbonic acid, which then dissociates to form bicarbonate ions CO3- and H+
100
Where is the bodies CO2 found?
5% dissolved in plasma
5% carried as carboxy-haemoglobin on proteins
90% carried as bicarbonate ions in plasma
101
How does fibrotic lung disease impede gas exchange?
Thickened alveolar membrane due to collagen deposition slows gas exchange
102
How does emphysema impede gas exchange?
Destruction of alveoli reduces surface area for gas exchange
103
How does pulmonary oedema impede gas exchange?
Fluid in interstitial space increases diffusion distance
104
What proportion of air inhaled doesn't actually partake in gas exchange (only goes to 'dead space')
1/3
105
How much air is usually in the anatomical/serial dead space?
150ml
106
What is the respiratory zone of the respiratory pathway?
The useful portion (over which gas exchange takes place)
107
What mathematical equation must you do to calculate alveolar ventilation rate?
Subtract dead space volume from tidal volume
108
What is the approximate usual pulmonary blood pressure?
~20-30mmHg
| Low
109
What does the low pulmonary blood pressure result in?
Lungs are not perfused evenly (more blood in base of lung)
110
What does V/Q ratio effect?
The concentration of O2 and CO2 in the alveoli and blood during respiration
111
How would you measure diffusion resistance?
Carbon monoxide transfer test
| 14% He, 0.1% CO inhaled. Hold breath for 10s. Rate of diffusion estimated due to its high affinity for CO
112
What is spirometry?
Lung function test
| Subject breathes from a closed chamber over water, chambers volume changes with ventilation
113
Define tidal volume
Volume in and out with each resting breath
114
Define inspiratory reserve volume
Extra volume that can be inhaled at rest
115
Define expiratory reserve volume
Extra volume that can be exhaled at rest
116
Define residual volume
Volume remaining after a maximal expiration (contributes to total lung capacity)
117
What is a lung capacity?
2 or more lung volumes added together
118
What is inspiratory capacity?
TV + IRV
119
What is vital capacity?
IRV + TV + ERV
120
What is a typical value for tidal volume?
0.5l
121
What is a typical value for expiratory reserve volume?
1.5l
122
What is a typical value for inspiratory capacity?
3.0l
123
What is a typical value for vital capacity?
5.0l
124
What is a typical value for inspiratory reserve volume?
2.5l
125
What is a typical value for residual volume?
0.8l
126
What is a typical value for functional residual capacity?
2.3l
127
What is a typical value for total lung capacity?
5.8l
128
What factors influence vital capacity?
Inspiration - compliance of lungs, force of inspiratory muscles
Expiration - airway resistance, increases as expiration proceeds
129
What is single breath spirometry?
Patient fills lungs, then breaths out as far and fully as possible. Volumes measured by detector over time - how much and how fast.
130
What is FEV 1.0?
Forced expiratory volume for the 1st second - volume expired over the 1st second, effected by how quickly air slows down, decreased if airways are narrowed.
131
What is FVC?
Forced vital capacity ~5l
132
What should the ratio between FVC and FEV 1.0 usually be?
More than 70% FVC
| If reversible, then suggestive of asthma
133
What is a vitalograph trace?
A plot of volume expired Vs time
134
Why is peak expiratory reserve rate often used as a screening test for airway narrowing?
Can be measured simply using a cheap device
135
What is a helium dilution test used for?
Measuring the volumes of air left in lungs after expiration
136
How is a helium dilution test carried out?
Patient inhales a known volume of gas containing a known concentration of helium. Helium is not metabolised, so as patient breaths, helium conc. changes as it gets diluted as it is in a larger volume. (Adding to air already in lungs)
137
What test would you use to measure dead space?
Nitrogen washout
138
How would you carry out a nitrogen washout test?
The last gas in the airways is the first out. Subject inhalers breath of pure O2, then exhales via a metre measuring the % N2. Initially only O2 expired, then mixture of O2 and air (including N2) from alveoli. Volume expired at transition is serial dead space.
139
At a pO2 of 13.3 kPa in the alveoli, how much O2 will be dissolved into blood?
0.13mmol/l
140
Describe the structure of haemoglobin
Tetramer (2 alpha, 2 beta subunits, each consisting of 1 haem and 1 globin), can hold up to 4 O2 molecules
141
Describe the structure of myoglobin
Monomer, 1 O2 molecule
142
What is myoglobin used for primarily?
O2 store for when O2 gets very low, e.g. In muscle
143
Why is %saturation a good measure to use?
Takes into account the amount of pigment present, independent of pigment concentration
144
What state is haemoglobin in when pO2 is low?
Tense - difficult for O2 to bind
145
What state is haemoglobin in when pO2 is high?
Relaxed - easy for O2 to bind
146
When is haemaglobin 'saturated'?
Above 9-10kPa
147
When is haemaglobin unsaturated?
Below 1kPa
148
When in haemaglobin half saturated?
3.5-4kPa
149
What will the effect of pO2 and O2 content in a patient with anaemia?
pO2 will be normal (saturation will be normal), but O2 content will be lower
150
What does tissue pO2 depend on?
How metabolically active the tissue is
151
What is a typical value for tissue pO2?
~5kPa
152
To what level does Hb saturation usually drop to?
~65% (~35% O2 given up)
153
What level can the pO2 not fall below in most cells? Why?
3kPa
| Must be this high to drive diffusion of O2 to cells
154
How does capillary density effect how low pO2 can be in tissue?
The higher the capillary density, the lower the pO2 can fall (doesn't have as far to diffuse)
There will be a high capillary density in very metabolically active tissue
155
How does decreased pH effect haemaglobin?
Promotes T-state (O2 dissociation)
156
How does increased pH effect haemaglobin?
Promotes R-state (O2 association)
157
What is the Bohr effect?
pH is lower in more metabolically active tissues (CO2 production), so extra O2 is given up
158
In which direction does the Bohr effect cause the curve to shift?
To the right
159
High way does increased temperature cause the oxygen disassociation curve to shift?
To the right
160
What effect does temperature have on haemaglobin affinity for O2?
Decreased
| Metabolically active tissues have slightly higher temperature, so more O2 is given up
161
When might maximum unloading of haemaglobin occur?
In tissues where pO2 can fall to low level and conditions where increased metabolic activity results in more acid environment and higher temperature - up to 70% of bound O2 can be given up
162
What is the maximum % of bound O2 which can be given up?
70%
163
Over the whole body, what percentage of bound O2 is generally given up?
~27%
| This will increase during exercise (oxygen reserve)
164
What effect does 2,3-diphosphoglycerate have on oxygen association curve?
Shifts curve to the right
| Allows more O2 to be given up at tissues
165
What happens to 2,3-DPG levels in stored blood?
Levels decrease due to refrigeration
166
What causes 2,3-DPG levels to increase?
Altitude, anaemia
167
When CO binds to Hb, what does it form? What is key about this reaction?
COHb
Irreversible reaction
Increases affinity of subunits for O2, so they wont give it up in tissues
168
At what level does CO poisoning become fatal?
If HbCO > 50%
169
What is cyanosis?
Bluish colouration due to unsaturated haemoglobin (deoxygenated Hb is less red than oxygenated Hb)
Can be peripheral or central
170
What causes peripheral cyanosis?
Poor circulation
171
What causes central cyanosis?
Poorly saturated blood in systemic circulation
172
What does pulse oximetry detect?
Hb saturation
173
How does pulse oximetry detect Hb saturation?
Difference in absorption of light between oxy and deoxy Hb
| Only detects pulsatile arterial blood, ignores levels in tissues and non-pulsatile venous blood
174
When may pulse oximetry give an incorrect reading?
If patient is anaemic - doesn't take into account how much Hb is present
175
What is a more accurate alternative to pulse oximetry?
Arterial blood gas
| However more invasive and time consuming
176
Does blood contain more CO2 or O2?
2.5 times more CO2 than O2
177
Approximately how much CO2 is dissolved in blood?
21mmol/l
178
Approximately how much O2 is dissolved in blood?
8.9mmol/l
179
What is CO2s major role in the blood?
Controlling blood pH (maintaining pH 7.35-7.45)
180
At pCO2 5.3kPa, how much CO2 is dissolved in blood?
1.2mmol/l
181
What is the pH of plasma dependent on normally?
How much CO2 reacts to form H+
182
What determines how much CO2 reacts to form H+ normally?
Concentration of CO2 dissolved (pushing reaction to the right, increasing H+)
Concentration of HCO3- (pushing reaction to left, decreasing H+)
183
What determines how much dissolved CO2 is in the blood normally?
Directly dependent on partial pressure of CO2. If pCO2 rises, pH will fall (more H+)
If pCO2 in alveoli is the determining factor, this is controlled by rate of breathing.
184
What cation is associated with HCO3- in the plasma?
Na+
185
How much bicarbonate is normally in plasma?
25mmol/l
186
What can the Henderson-Hasselbalch equation be used for?
Calculating pH from pCO2 and HCO3- conc.
187
Where is most of the HCO3- found in the blood produced?
In RBCs
| Contain enzyme carbonic anyhydrase CA
188
What is the reaction catalysed by carbonic anhydrase in RBCs?
CO2 + H2O ---> H+ + HCO3-
189
How is HCO3- removed from RBCs once it has been produced?
Via chloride bicarbonate exchanger on their cell surface
190
What determines how much HCO3- is produced by erythrocytes?
How much H+ is bound to haemoglobin
191
Do RBC control HCO3- concentration in plasma?
No
192
What controls amount of HCO3- in blood?
Kidneys via excretion
193
What determines how much CO2 is in the blood?
Rate of breathing
194
What buffers extra acids in the blood (e.g. Lactic, keto...)
Hydrogen carbonate
195
How does bicarbonate act as a buffer for extra acids produced by the body (e.g. Keto, lactic...)
Acids react with HCO3- to produce CO2, therefore decreasing concentration of HCO3-. CO2 produced is removed by breathing and pH changes are minimised.
196
What determines arterial pCO2?
Alveolar pCO2
197
What does buffering of H+ by haemoglobin depend on?
Level of oxygenation (amount bound is dependent on state of Hb molecule)
198
How does having lots of O2 bound to a Hb molecule effect the amount of H+ ions it binds?
More O2 - R state - less H+ bound
199
How does having not much O2 bound to a Hb molecule effect the amount of H+ ions it binds?
Less O2 bound to Hb - T state - More H+ ions bound
200
What does more H+ ions being able to bind to Hb (in venous blood) incur?
More HCO3- can be produced, therefore more CO2 (unreacted) is present in plasma
201
When in lungs, and Hb gives up O2, returning to relaxed state, what happens to the H+ associated to it?
Hb gives up extra H+, which then goes on to react with HCO3- to form CO2, which is then exhaled
202
What are carbamino compounds?
CO2 bound directly to proteins (onto amino groups on globin of Hb)
203
Does the binding of CO2 to proteins contribute to blood pH?
No, but does contribute to CO2 transport
204
Where are most carbamino compounds formed?
At the tissues, because pCO2 is higher and the unloading of O2 facilitates binding of CO2 to Hb (which will then be given up at lungs)
205
What are the 3 forms by which CO2 are transported? (And what proportion of CO2 transport is via this mechanism)
Dissolved (10%)
As hydrogen carbonate (60%)
As carbamino compounds (30%)
206
What is the approximate value of CO2 in whole arterial blood?
~21.5mmol/l
207
What is hypoxia?
O2 deficiency at tissue level. If it persists tissue will undergo ischaemic damage or necrosis
208
What are the 4 types of hypoxia?
Hypoxaemic, or respiratory hypoxia
Anaemic hypoxia
Stagnant, or circulatory hypoxia
Cytotoxic hypoxia
209
What is hypoxaemic (or respiratory) hypoxia?
Poor oxygenation at the lungs, low pO2 and low O2 saturation
210
What is anaemic hypoxia?
Normal pO2, but insufficient Hb to carry the O2, e.g. CO poisoning
211
What is stagnant, or circulatory hypoxia?
Reduced delivery of O2 due to poor perfusion. Could be global (e.g. Shock), or local (e.g. Peripheral vascular disease)
212
What is cytotoxic hypoxia?
O2 delivery is adequate, but tissues unable to utilise O2, e.g. Cyanosis poisoning
213
What is the normal level of O2 saturation?
94-98%
214
What is the normal pO2?
11.1 - 14.4 kPa
215
At what level of O2 is tissue at serious risk of being damaged?
Less than 90%
216
At what O2 saturation level is tissue at serious risk of being damaged?
Less than 8kPa
217
Describe type 1 respiratory failure (pO2, O2 saturation, pCO2)
pO2 of arterial blood low (less than 8kPa)
O2 saturation less than 90%
pCO2 normal or low
218
Describe type 2 respiratory failure (pO2, O2 saturation, pCO2)
pO2 in arterial blood less than 8kPa
O2 saturation less than 90%
pCO2 high, above normal range (4.3-6.4 kPa)
219
What are the 3 mechanisms for respiratory failure?
Ventilators (pump) failure - unable to move sufficient air in/out of the lungs
Poor diffusion across alveolar membrane
Mismatching of ventilation and perfusion
220
What happens when V/Q ratio is less than 1?
Alveolar pO2 falls, pCO2 rises
| Type 1 respiratory failure
221
What might call V/Q ratio to fall below 1?
Could be due to reduced ventilation of part of lung, or reduced perfusion of part of lung (increases Q as rest of lung receives excess of what's available)
222
What is the treatment for type 1 respiratory failure?
Treat cause
| Oxygen therapy might help hypoxia
223
What is the treatment for type 2 respiratory failure?
Treat cause
| Problems of hypercapnia might require assisted ventilation (particularly if acute)
224
What are the clinical features of hypoxia?
Exercise intolerance
Tachypnoea (may be perceived as breathlessness)
Confusion
Central cyanosis (late/when O2 saturation <85%)
225
When is cyanosis present?
When more than 50gm/l of desaturated Hb is in the blood
226
What is cyanosis?
Purplish decolorisation of skin and mucous membranes due to the colour of desaturated Hb
227
What does central cyanosis indicate ?
Arterial hypoxia
| O2 Saturation <85%
228
What level of O2 saturation does central cyanosis indicate?
Less than 85%
229
What are the consequences of chronic hypoxia?
Increased number of RBC, containing more 2,3 DPG
Hypoxia vasoconstriction of pulmonary arterioles (usually to aid V/Q ratio in regions) - can cause pulmonary hypertension, corpulomale
230
What changes occur with chronic hypercapnia?
CSF acidity corrected by choroid plexus (HCO3- ion pumping)
Central chemoreceptors 'reset' to higher pCO2
Peripheral chemoreceptors remain sensitive to hypoxia
Respiration now driven by hypoxia (pO2)
231
Why is O2 administration dangerous in patients with COPD?
Hypoxia is now the stimulus driving respiration - correcting this may reduce ventilation.
Reducing hypoxic vasoconstriction in poorly ventilated alveoli may worsen V/Q mismatch
232
List 4 possible causes of hypoventilation
Respiratory centre depression e.g. Head injury, drugs
Muscle weakness of respiratory muscles e.g. Damage, disease, nerve damage
Chest wall problems e.g. Scoliosis, morbid obesity
Hard to ventilate lungs e.g. Severe fibrosis
233
List some common flora of the upper respiratory tract
Viridian's streptococci, Neisseria spp, anaerobes, candida spp.
Also (but less common):
Streptococcus pneumoniae, streptococcus pyogenes, haemophillus influenzae
234
List some of the natural defences of the respiratory tract
Muco-ciliary clearance mechanisms, nasal hairs, ciliates columnar epithelium of tract
Coughing/sneezing reflex
Respiratory mucosal immune system. Lymphoid follicles of pharynx and tonsils, alveolar macrophages, secretory IgA and IgG
235
List 5 common compromises to the respiratory tract defences
```
Poor swallowing
Abnormal ciliary function
Abnormal mucus
Dilated airways
Defects in host immunity
```
236
What might cause poor swallowing?
CVA, muscle weakness, alcohol
237
What might cause abnormal ciliary function ?
Smoking, viral infection
238
What might cause abnormal mucous?
Cystic fibrosis
239
What might cause dilated airways?
Bronchiectasis
240
What might cause defects in host immunity?
HIV
| Immunosuppression
241
What is the most common causes of upper respiratory tract infection?
Viruses
| E.g. Rhinovirus, influenza
242
What is the most common causes of lower respiratory tract infection?
Bronchitis, empyema, pneumonia, lung abscess, bronchiolitis
243
What is acute bronchitis?
Inflammation of medium sized airways, mainly in smokers. Cough, fever, increased sputum production, shortness of breath. CXR normal.
244
What might cause acute bronchitis?
Viruses - e.g. S. Pneumonias, H. Influenzae, M. Catarrhalis.
245
What is the treatment for acute bronchitis?
Physiotherapy +/- antibiotics
246
What is pneumonia?
Inflammation of lung alveoli. Patients are unwell - 20-40% admitted to hospital
247
Describe the presentation of a patient with pneumonia
Fever, cough, pleuritic chest pain, shortness of breath. Often localising signs and abnormal CXR
248
How is pneumonia classified?
Clinical setting (community/hospital acquired)
Presentation (acute/chronic)
Organism (bacterial/viral/fungal)
Lung pathology (lobar, bronchi, interstitial)
249
What is the cellular presentation of pneumonia?
Acute inflammatory response - exudation of fibrin-rich fluid. Neutrophil and macrophage infiltration
250
What factors in the patient history might be suggestive of pneumonia?
Pre-existing lung disease, immune-compromisation, geography, seasons, epidemics, travel, exposure to animals
251
What is a nosocomial infection?
A hospital acquired infection
252
What is a common mechanism of spread for hospital awaited pneumonia?
Ventilator associated
253
What are the main causative organisms for community acquired pneumonia?
```
Streptococcus pneumoniae
Haemophilus influenzae
Moraxella catarrhalis
Staphylococcus aureus
Klebsiella pneumoniae
```
254
What are the symptoms of pneumonia?
Cough (+/- sputum), shortness of breath, fever, rigours, pleuritic chest pain, malaise, nausea, vomiting
255
What will you find on examination of a patient with pneumonia?
Pyrexia, tachycardia, tachypnoea, cyanosis, bronchial breathing, crackles, dullness to percussion, tactile voice fremitus
256
What investigations should you do for a patient with pneumonia?
```
FBC
U & Es
CRP
Arterial blood gases
CXR
Microbiological samples/investigations
```
257
What microbiological samples/investigations should you do for a patient with pneumonia?
```
Sputum (induced if required)
Blood culture
Bronchodilator alveolar lavage fluid BAL
Nose and throat swabs or NPAs
Urine (antigen test for legionella/pneumococcus)
Serum (antibody test)
```
258
What could contribute towards points on the CURB 65 score?
```
Confusion
Urea >7mmol/l
Respiratory rate >30
Blood pressure <90 systolic, <60 diastolic
Over 65yrs
```
259
What score on the CURB 65 scale constitutes patient to be managed as 'severe'?
2-5
260
What does antibiotic treatment for pneumonia depend upon?
Probable infection, personal risk factors, community Vs hospital, severity ect
261
What antibiotics should you give for mild-moderate pneumonia?
Amoxicillin
| Or doxycycline/clarithromycin
262
What antibiotics should you give for moderate-severe pneumonia?
Hospital admission
| Co-amoxiclav AND clarithromycin/doxycycline
263
What are the possible complications of acute bacterial pneumonia?
Lung abscess, bronchiectasis, empyema
264
What might increase the risk of complications arising from a pneumonia infection?
Resistant organism, wrong diagnosis, immunosuppression, proximal obstruction, empyma/abscess.
265
What type of organism is S. Pneumoniae?
Gram positive cocci (pairs, diplococci)
266
What sort of pneumonia does S. Pneumoniae cause?
Acute onset, severe. Fever/rigours
267
What do you use to treat pneumonia caused by S. Pneumoniae?
Benzyl penicillin of amoxicillin
268
What causes atypical pneumonia?
Organisms without a cell wall - meaning penicillins (cell-wall active antibiotics)won't work on them.
269
List some atypical organisms that may cause pneumonia
Leigionella, chlamydia, coexiella, mycoplasure
270
What would you use to treat atypical pneumonia?
Agents active on protein synthesis - macrolides, tetracyclines
271
What extrapulmonary features might be present in atypical pneumonia?
Hepatitis, low Na+
272
What would be a typical CXR for viral pneumonia?
Patchy or diffuse ground glass opacity on CXR
273
What can severe viral pneumonia present similarly to?
Adult respiratory distress syndrome ARDS
274
What are the features of viral pneumonia?
Damage to cells lining airways/alveoli by virus and immune cells. Fluid filled air spaces interferes with gas exchange. Can be mild - severe
275
What accessory muscles are used for additional inspiration?
Sternomastoid, scalenus (anterior, medial posterior), pectoralis maj/minor, internal fibres of serratus anterior and posterior, serrated (anterior, posterior)
276
What accessory muscles are used for forced expiration?
Abdominal wall muscles, (rectus abdominus, transversis abdominus, external/internal oblique muscles)
277
When is pneumonia classed as hospital acquired?
If patient develops symptoms after 48hrs or more in hospital
278
What is aspiration pneumonia?
Exogenous material or secretions in respiratory tract
279
When is aspiration pneumonia most commonly seen?
In patients with neurological dysphagia (e.g. Strokes), epilepsy, alcoholic. IVDU and nursing home residents at risk
280
How is pneumonia prevented?
Immunisation (e.g. flu vaccine)
Chemoprophylaxis (e.g. Oral penicillin) to patients with high risk of lower RTI
Smoking advice
281
What are the most common causative organisms for TB?
Mycobacterium tuberculosis
Mycobacterium bovis
Mycobacterium africanum
282
What sort of bacteria are the mycobacterium species, causing TB?
Non-motile, rod-shaped, aerobes.
They have long chain fatty (mycolic) acids, complex waxes and glycolipids in their cell wall. This gives structural rigidity, staining characteristics, acid alcohol fast.
Relatively slow growing (generation times 15-20hrs)
283
How is tuberculosis transmitted?
Not easy to catch! Prolonged exposure facilitates transmission.
Spread by respiratory droplets. Air remains infectious for 30mins.
Infectious dose 1-10 bacilli, less than 10um particles suspended in droplets.
Reach lower respiratory airway macrophages
284
Describe the pathogenesis of TB
Inhaled aerosols
Engulfed by alveolar macrophages
Local lymph nodes
Primary complex (5% forms active TB here)
Initial containment of infection
Latent infection (can either self cure, or go on to form post primary TB)
285
What would the TST test result be for active TB?
Positive
286
What would the TST test result be for latent TB?
Positive
| Also IFN gamma test result positive
287
What would a CXR for a patient with latent TB look like?
Normal
288
What would a CXR for a patient with active TB look like?
Abnormal
289
What would the result of sputum smears/culture be for a patient with latent TB?
Negative
290
What would the result of sputum smears/culture be for a patient with active TB?
Positive
291
Would a patient with patent TB have symptoms?
No
292
Would a patient with active TB have symptoms?
Yes
| Cough, fever, weight loss
293
What might stimulate post primary TB?
Reactivation or exogenous reinfection
294
When is TB classed as post primary TB
When it appears over 5yrs after primary infection
295
Can clinical presentation of post primary TB be extra pulmonary?
Yes
296
List some risk factors for reactivation of TB
HIV, substance abuse, organ transplants, low BMI, immunosuppression, prolonged therapy with corticosteroids, DM
297
What forms in the lungs of patients with active TB?
Caseating granuloma (with caseous necrosis at the centre)
298
List some frequent sites for TB
Pulmonary (most cases)
Extrapulmonary - lymph nodes, pleura, kidneys, brain... (found more in immunosuppressed patients/young children)
Military - carried to all parts of the body via bloodstream (rare)
299
List some risk factors for TB
Non U.K. Born/recent migrants
HIV/immunosuppression
Homeless, drug users, prison
Close contacts infected
300
What are the symptoms of pulmonary TB?
Fever, night sweats, weight loss, anorexia, tiredness, malaise, cough, breathlessness (if pleural effusion)
301
What are the signs on examination of pulmonary TB?
Crackles in effected area. Often no chest signs despite CXR abnormality
302
What investigations should you do for pulmonary TB?
CXR, sputum (3 early morning samples, min volume 5ml, induced if needed), bronchoscopy
303
What might be visible in a CXR from a patient with pulmonary TB?
Cavitation usually develops within consolidation. Healing results in fibrosis
304
What are the limitations of microscopy?
Sputum smears only have 60% sensitivity (increased with more samples)
Operator skills dependent
305
What is the 'gold standard' for TB diagnosis?
Culture
306
What is a tuberculosis sensitivity test TST?
Tuberculin injected intradermally, read 48-72hrs later.
Tests if you've been exposed, not if you've had the disease.
Subject to interpretation, can give false results, but is cheap and doesn't require a laboratory infrastructure
307
What are interferon gamma releasing assays IGRAs?
Detection of antigen-specific IFN-gamma production. No cross reaction with BCG. Can distinguish latent and active TB. Similar problems with sensitivity and specificity
308
What are the 1st line anti TB drugs?
Rifampicin, isoniazid, pyrazinamide, ethambutol
| Always in combination!
309
What are some second line medications for TB?
Quinolones (moxifloxacin), injectables, capreomycin, kanamycin, amikacin, ethionamide, prothionamide...
310
What are some key points for treating TB?
Early and adequate treatment, close monitoring of compliance. Check no secondary transmission and cases.
311
Describe the multidrug therapy one would typically give a patient with TB (RHZE), and how it works
Rifampicin - raised transaminatse and induces cytochrome P450. Orange secretions (orange urine!)
Isoniazid - peripheral neuropathy (pyridoxine 10mg od). Hepatotoxicity
Pyrazinamide - hepatotoxicity
Ethambutol - visual disturbance
Vitamin D
Surgery?
312
Describe the duration of drugs taken for TB
3/4 drugs for 2 months, then rifampicin for 4 months. 18 months if CNS TB. Cure rate 90%
313
How long would a patient be required to take medication if they had CNS TB?
18 months
314
What is MDR TB resistant to?
Rifampicin and isoniazid
315
What is XDR TB resistant to?
Rifampicin and isoniazid
| Also fluroquinolones and at least 1 injectable
316
How do you treat drug resistant TB?
4-5 drug regimes for longer duration
317
What sort of drugs would you use to treat drug resistant TB?
Quinolones, aminoglycosides, PAS, cycloserine, ethionamide
318
What might induce miliary TB?
Rupture of caseous pulmonary focus into blood vessel
319
What is miliary TB?
Bacilli spreading throughout bloodstream - widespread infection
Can be during primary infection or during reactivation. Lungs are always involved, but few respiratory symptoms
320
What might be some symptoms of miliary TB?
Fever, dry cough, very unwell
321
What is done to help reduce spread of TB?
All forms of TB are compulsorily notifiable under the public health act 1984. This enables data, to detect and monitor outbreaks, and triggers contact tracing procedures
322
What is the BCG vaccine?
A live attenuated virus (M. Bovis strain), given in high prevalence communities only. 70-80% effective
323
What is asthma?
A chronic inflammatory disease of the airways, resulting in reversible airway obstruction
Inflammation, bronchoconstriction, mucus
324
Describe the process by which an asthma attack occurs
Environmental trigger inhaled
Type 1 hypersensitivity reaction
Airway narrowing (smooth muscle contraction, mucus production, inflammatory cell infiltration)
Remodelling - damaged epithelium, increased smooth muscle thickness
325
What might trigger an asthma attack?
Indoor - pets, mould, dust mites, medications (NSAIDs, beta blockers)
Outdoor - cold, pollens, tobacco smoke, pollutants, exercise
326
Is there any standardisation of type, severity, or frequency of symptoms for asthma?
No
327
What are the symptoms of asthma?
```
RECURRENT
Breathlessness
Chest tightness
Wheeze
Cough (worse at night/exercise. Dry)
Tracheal tug, recession, nasal flaring
Accessory muscle use
```
328
What are the stages of examination of a patient with asthma?
Full history, inspection, palpating, percussion, auscultation, peak flow, spirometry
329
What is the management of a patient with asthma?
Education - how to use inhaler properly
| Prevention - change pillows/bedsheets frequently, fresh air, no smoking...
330
What does SABA stand for?
Short acting beta agonist
331
What is SABA used for?
Helps relax respiratory smooth muscle, 'quick relief' of asthma symptoms
332
When would you step up an inhaler?
If used more than 3 times a week, or if nocturnal symptoms
333
What is a steroid used for when treating asthma?
Reduces inflammation, inhibits inflammatory cells/mediators
334
When is LABA used?
Used in asthma patients who still have asthma symptoms despite steroid. Slower onset of action therefore not for an acute asthma attack
335
What does LABA stand for?
Long acting beta agonist
336
What is the criteria for a mild asthma attack?
```
Sats >92% on air
Pulse <110
RR <25
Speech normal
Minimal wheeze
PEFR >75% predicted
```
337
What are the criteria for a moderate asthma attack?
```
Sats >92% in air
Pulse <110
RR <25
Speech normal
Wheeze +++
PEFR 50-75% predicted
```
338
What is the criteria for a severe asthma attack?
```
Sats <92% in air
Pulse >110
RR >25
Can't complete sentences
No wheeze (not enough air in lungs)
PEFR 35-50% predicted
Needs to be in hospital (resuss)
```
339
What is the criteria for a life threatening acute asthma attack?
```
Sats <92% in air - cyanosis
Silent cheat - poor respiratory effort (tired muscles)
Altered consciousness
Exhaustion
PEFR 35% predicted
May need to be intubated
```
340
What treatment would you give for an asthma attack?
Oxygen
Salbutamol nebulisers, atrovent nebulisers 'back to back'
IV access
May need to incubate and ITU admission
341
What is COPD?
Chronic obstructive pulmonary disease
Characterised by airflow obstruction that is progressive, not fully reversible and does not change markedly over several months. Predominantly caused by smoking.
Umbrella term encompassing emphysema and chronic bronchitis - patients may have features of either or both
342
What is emphysema?
Pathological process in which there is destruction of the terminal bronchioles and distal airspaces. This leads to loss of alveolar surface area, therefore impairment of gas exchange. Process often progresses to the development of larger redundant air spaces within the lung, called bullae.
Emphysema causes the destruction of the supporting tissue surrounding the small airways and therefore their close/collapse during expiration - airflow obstruction of small airways.
In addition, the loss of elastic tissue in the lung causes the lungs to hyperinflate as the lungs are unable to resist the natural tendency of the rib cage to expand outwards.
343
What is chronic bronchitis?
Chronic mucus hypersecretion that frequently occurs in smokers. Caused by inflammation in the large airways (often due to cigarette smoke), leading to proliferation of mucus producing cells in the respiratory epithelium.
Resulting chronic productive cough and frequent respiratory infections, frequently persists even after quitting smoking. Results in airflow obstruction due to remodelling and narrowing of airways
344
What, other than smoking, might cause COPD?
Alpha-1-antitrypsin deficiency (rare genetic condition)
| Pollution (developing countries)
345
What are the symptoms of COPD?
Cough/sputum production usually the first signs, although patients usually don't present until they are breathless.
346
Describe the MRS dyspnoea score system for the grading of breathlessness
1 - Not troubled by breathlessness except on strenuous exercise
2 - Short of breath when hurrying or walking up a slight hill
3 - Walks slower than contemporaries on level ground due to breathlessness, or has to stop for breath when walking at own pace
4 - Stops for breath after walking about 100m, or after a few minutes on level ground
5 - Too breathless to leave house, or breathless when dressing
347
What are the signs of COPD?
'Purse lip' breathing - protective manoeuvre that increases the pressure within airways, causing a reduction or a delay in the closure of the airways
Tachypnoea
Using accessory muscles
Hyperinflation (diaphragm/resp muscles must work harder to ventilate lungs)
Wheeze/quiet breath sounds on ausculation
Cyanosis and CO2 retention, right heart failure (cor pulmonale) with oedema
348
How may COPD be diagnosed?
Measurement of airflow obstruction is essential - this is achieved with spirometry
349
What is spirometry?
Subjects are asked to perform a forced expiratory manoeuvre (blowing out as hard and fast as possible into a sealed tube), and the volume of expelled air is plotted against time
350
What is the spirometry values for someone with COPD?
FEV1<80% predicted
| FEV1/FVC ratio <70%
351
What is the NICE guidelines for mild airflow obstruction spirometry value?
FEV1 50-80% predicted
352
What is the NICE guidelines for moderate airflow obstruction spirometry value?
FEV1 30-49% predicted
353
What is the NICE guidelines for severe airflow obstruction spirometry value?
FEV1 <30% predicted
354
What does COPD diagnosis depend on?
A combination of suggestive symptoms and signs, together with the presence of airflow obstruction on spirometry (FEV1<80% predicted and FEV1/FVC ratio <70%)
355
What are some suggestive features of COPD?
Smoker or ex smoker
Older patient (>40yrs) and onset of symptoms later in life
Chronic productive cough
Breathlessness that is usually persistent and progressive
356
What other investigations might you do for COPD?
CXR - not diagnostic, but mandatory to exclude other diagnosis
Arterial blood gas to assess respiratory failure
Alpha -1-antitrypsin blood test for younger patients
High-resolution computed technology (HRCT) scanning, detailed assessment of the degree of alveolar destruction. Helpful in considering surgical intervention, or if doubtful diagnosis - not required for routine assessment
357
What treatment is available for COPD?
```
Smoking cessation
Pulmonary rehabilitation
Bronchodilation
Antimuscarinics
Steroids
Mucolytics
Diet-supplements/dietician review
Supportive e.g. Flu vaccine
Long term oxygen therapy
Lung volume reduction
```
358
What is the treatment for stable COPD?
```
Bronchodilators
Steroids - inhaled
Antimuscarinics
Mucolytics
Methylxanthines
```
359
What is the mechanism of action for beta 2 agonists in COPD?
Ligand binds to receptor, activating adenylcyclase, increasing cAMP and activating protein kinase (PKA), leading to phosphorylation of downstream targets (myosin light chain kinase MLCK). Leads to relaxation of smooth muscle in airway - bronchodilation.
360
What are possible side effects of using beta2 agonists?
Tachycardia (atrial Beta2 receptors, palpitations)
Tremor (skeletal Beta 2 receptors)
Hypokalaemia (skeletal muscle uptake of K+)
361
How do anticholinergics work in COPD?
Synergistic with Beta2 agonists
Blocks ACh by blocking the binding of ACh to its receptor in nerve cells thus inhibiting parasympathetic impulses (as that's its target)
362
Give some examples of anticholinergics
Ipratropium (short acting muscarinic)
| Tiotropium (longer acting)
363
What are some local adverse effects of anticholinergics?
```
Dry mouth/cough
Sore throat
Upper respiratory tract infection
Bitter taste
Nausea
```
364
What are some possible systemic adverse effects of anticholinergics?
Supraventricular tachycardia
Atrial fibrillation
Urinary difficulty/retention
Constipation
365
Give some examples of methylxanthines used for COPD
Theophylline
| Aminophylline
366
Describe the mode of action of methylxanthines, used for COPD
Bronchodilation. Increase respiratory drive, anti-inflammatory effects.
Inhibition of phosphodiesterases (which break down cAMP, so inhibition leads to an increase in cAMP - bronchodilation)
367
Why do methylxanthines require blood level monitoring?
Toxicity - tachycardia, SUT, nausea, seizures
368
What are the side effects of long term steroids?
Thin skin, bruising, cataracts, adrenal insufficiency, osteoporosis, diabetes, increased weight, (fluid retention), mental disturbance, GI symptoms, proximal myopathy
369
What might mucolytics be up for?
Can help reduce the thickness of sputum, helping airways clearance
370
Give an example of a mucolytic
Carbocysteine
371
What are the key messages for drug therapy in COPD?
Bronchodilator therapy may provide symptomatic relief
Steroids can help reduce inflammatory pathways
Mucolytics can reduce sputum thickness
Drugs can help improve quality of life and reduce exacerbation frequency, but do not provide cure or improve survival in COPD
Education on inhaler technique is essential as well as side effects counselling
372
What is reconditioning in COPD?
Many patients with COPD avoid exercise/physical activity due to breathlessness......
Viscous cycle of increasing social isolation and inactivity, leading to worsening of symptoms....
373
What is the reconditioning cycle?
Feel bad due to illness, so avoid activities that exacerbate feeling such, so do less, so muscles weakens, so feel worse, so feel depressed, so avoid activities......
374
What is the aim of pulmonary rehabilitation?
To break the deconditioning cycle!
375
What is pulmonary rehabilitation?
6-12wk programme of supervised exercise, advise, education ect.
Aims to break the deconditioning cycle!
376
How long a day must a patient be on oxygen for a survival benefit?
At least 16hr a day
377
What can be used to prevent renal and cardiac damage due to extended periods of hypoxia in COPD?
Long term oxygen therapy
378
When might long term oxygen therapy be offered to a patient?
If pO2 is persistently below 7.3 kPa, or below 8kPa with cor pulmonale
Patients must be non-smokers and not retain high levels of CO2 (checked in hospital on O2 first). Must have home fire risk assessment for safety
379
What must patients be in order to be offered long term oxygen therapy?
Patients must be non-smokers and not retain high levels of CO2 (checked in hospital on O2 first). Must have home fire risk assessment for safety
380
What surgical options might be used for treatment of COPD?
Lung volume reduction - reduction of hyperinflation is principle aim - gets rid of dead space.
Lung transplant - rare, used in young patients
381
What multidisciplinary people might be involved in the care of a patient with COPD?
Physicians, GPs, specialist nurse, physio, pharmacist, occupational therapists, dietician, surgoen
382
What is the treatment of acute exacerbations of COPD?
Aim for sats 88-92% by controlled O2 therapy
Nebulisers - bronchodilators
Steroids - oral (possibly IV)
Antibiotics if infective features (WCC, purulent sputum, raised CRP)
Repeat ABG, if no better consider non-invasive ventilation or referral to ITU for invasive ventilation
383
What is non invasive ventilation?
The provision of ventilatory support through upper airways via mask/similar device
384
When might non invasive ventilation be used?
Used for acute exacerbations of COPD with type 2 respiratory failure and mild acidosis (pH 7.25-7.35)
Patients must be conscious to use it!
385
When must you NOT use non invasive ventilation?
```
Untreated pneumothorax
Facial injury
Vomiting
Agitated
Life threatening hypoxia
Lots of upper airway secretions
Unconscious
```
386
What are the markers of addiction?
Use despite knowledge of harmful consequences
Cravings during abstinence
Failure of attempts to stop
Withdrawal symptoms during abstinence
387
How long does it take for ACh receptors to desensitise after the last cigarette?
6-12wks
388
How many puffs of a cigarette does it take to bind 50% of ACh receptors?
1-2
389
What receptors does nicotine act upon? What does this stimulate?
Nicotinic acetylcholine ACh receptors, stimulating dopamine release
390
What causes the satisfaction associated with smoking?
Dopamine release as a results of nicotine binding to nicotinic ACh receptors
391
What happens to ACh receptors following chronic nicotinic exposure?
ACh receptors enter up regulated state, increases affinity and functional sensitivity to an agonist
392
What is the quickest method of nicotine delivery?
Cigarette (2 x as fast as a spray, 3 x as fast as gum/inhaler/tablet)
393
What is the most effective treatment for tobacco related disease?
Quitting smoking!
394
Why is it particularly important to advice patients to quit smoking?
2nd most effective way to get people to quit smoking
| If don't condone it, patients may assume it's acceptable behaviour
395
What are the 3 As for discussing smoking with a patient?
Ask - and record smoking status (current, ex, non)
Advice - patient of healthcare benefits (best thing for health is stopping!)
Act - on patients response (build confidence, give info, refer, prescribe, follow up)
396
Why does NRT aid successful quitting of smoking?
Nicotine withdrawal causes discomfort, NRT provides temporary nicotine substitution (weaning)
Via therapeutic routes provides relief and encourages complete abstinence.
Doubles success rate of quitting
397
Why is NRT better than just reducing the number of cigarettes gradually?
NRT contains nicotine only. Short and long acting agents can be used in combination
398
What does champix - varenicline tartrate do?
Reduces craving for nicotine by binding to nicotine acetylcholine receptors in the brain. High affinity and selectivity, act as a partial agonist.
Reduces withdrawal symptoms, reduces the satisfaction a smoker gets from smoking.
Should be taken for ~3mths. Can be combined with NRT prescribing, relatively good success rate.
399
What are some mechanisms of harm reduction for smoking, if patient can't give up entirely?
```
Cut down to stop e.g. Using 1 or more NRT
Smoke less (long term reduction)
Stop temporarily (abstain for an agreed length of time)
E-Cigarettes (toxins present, but lower, so fewer risks)
```
400
What risk factors are there for cancer other than smoking?
Asbestos
Radon
Occupational carcinogens (e.g. Cr, Ni, arsenic, coal dust)
Genetic/family factors
401
What is the criteria for a screening test to be successful?
Must:
Be for a disease with serious consequences
High prevalence of detectable disease
Test detects little pseudo-disease (no over diagnosis)
Test detects disease before the critical point
Test causes little morbidity
Test affordable and available
Treatment for disease exists
Treatment more effective when applied before symptomatic detection
Treatment not too risky or toxic
402
Is there currently a screening test for cancer?
No
| Possibly CT in the future?
403
What is the primary reason most lung cancer is untreatable?
Found too late (80%)
404
What does a successful screening test do?
Decreases disease specific mortality
405
List some common places for lung cancer to spread to
Brain, draining lymph nodes, pericardium, lung, pleura, liver, adrenals, bone
406
What staging tests would you perform for lung cancer?
CT scan and PET scan
Do PET scan as well as CT as this shows the activity of tissue, suggesting if it is cancer or not. Also picks up some missed by CT scan.
407
What are all the frequently used investigations/staging tests for lung cancer?
```
CT scan and PET scan (standard procedure)
CXR
MRI
USS
Bone scan
ECHO
```
408
What possible methods of tissue sampling are there for lung cancer?
Bronchoscopy - endobronchial bx, wash, EBUS, radial EBUS, EUS
USS-neck node, lung/chest wall mass, pleural fluid, liver
CT biopsy - lung, pleura
Thorocoscopy - medical
Surgical - mediastinoscopy, VATS pleural box, rigid bronchoscopy, neck and axillary nodal excision, VATS excision bx, brain bx, bone bx
409
What are the symptoms of a primary lung tumour?
```
No symptoms (most common presentation!)
Cough, wheezing, dyspnoea, haemoptysis, lung infection, chest/shoulder pain, weight loss, lethargy/malaise
```
410
What is haemoptysis?
Coughing up blood
411
What is dyspnoea?
Shortness of breath
412
What might the symptoms of regional metastases of lung cancer be?
Bloated face (SVC obstruction), hoarseness (left recurrent laryngeal nerve palsy), dyspnoea (anaemia, pleural or pericardial effusions), dysphagia (oesophageal compression), chest pain (parietal pleural involvement), post obstructive pneumonia (tumour blocks airway, sputum collects, bacteria infect)
413
What might be some symptoms of distant metastases of lung cancer?
```
Bone pain/fractures
CNS symptoms (headache, double vision, confusion)
Metabolic - thirst and constipation (hypercalcaemia), seizures (hyponatraemia)
```
414
What are some possible signs of lung cancer?
Cachexia, pale conjunctiva, cervical lymphadenopathy, horners syndrome, consolidation, signs of pleural effusion, muffled heart sounds, liver enlargement, skin metastases, neurological long tract signs, enlarged veins (vena cava obstruction)
Or... no signs
415
What are the endocrine paraneoplastic syndromes that might be seen in lung cancer?
Hypercalcaemia
Cushing's syndrome
Inappropriate ADH secretion (SIADH)
416
What are the haematological paraneoplastic syndromes that might be seen in lung cancer?
Anaemia
| Thrombocytosis
417
What are the cutaneous paraneoplastic syndromes that might be seen in lung cancer?
Dermatomyositis
418
What are the neurological paraneoplastic syndromes that might be seen in lung cancer?
Encephalopathy
Peripheral neuropathy
Eaton-Lambert syndrome
419
What are the skeletal paraneoplastic syndromes that might be seen in lung cancer?
Finger clubbing
420
When would you carry out a biopsy in lung cancer?
If patient is well enough to sustain it, and results might change your management plan
421
What is a carcinoma?
An invasive malignant epithelial tumour
422
What are the main types of cancer present in lung cancer?
```
Non-small cell:
- Squamous cell carcinoma
- Adenocarcinoma
- Large cell carcinoma
Small cell carcinoma
```
423
What molecular markers might you look for in lung cancer?
EGFR mutations
ALK mutations
KRAS mutations
PD1 mutations
424
Describe the stages in the performance status of a patient with lung cancer
0 - No symptoms, normal activity level
1 - Symptomatic, but able to carry out normal daily activities
2 - Symptomatic, in bed or chair less than half the day. Needs some assistance with daily activities
3 - Symptomatic, in bed or chair more than half the day
4 - Bedridden
5 - Dead
425
What are the different treatment options for lung cancer?
Surgery - mostly for non-small cell carcinoma
Radiotherapy - 'radical' (curative intent), or 'palliative'
Combination chemotherapy - survival increase, symptom control, neoadjuvant or adjuvant therapy (potentially curative in small cell)
Combination therapy - chemo-radiotherapy (potentially curative)
'Biological (targeted)' therapies - based on mutational analysis (EGFR, ALK, RAS, PD1)
Palliative care - active symptom control e.g. Analgesia, radiotherapy, airway stents, anxiolytics, nutritional support, patient support groups
426
What is an X-ray?
An electromagnetic wave of high energy and very short wavelength, which is able to pass through many material opaque to light.
A photographic of digital image of the internal composition of the body, produced by X-rays being passed through the body part and being absorbed to different degrees by different tissues.
This is displayed as levels of contrast on a grey scale (black to white)
427
What is the most common orientation for an X-ray?
Posterior to anterior (PA)
| Assume it is such unless written otherwise on X-ray
428
Why are anterior to posterior (AP) X-rays not so useful?
Heart is closer to the receptor, and therefore is magnified. Can't make judgement of heart on AP. Generally AP only done if patient can't stand up.
429
What must be included in a chest x-ray?
1st rib, lateral margin of ribs, costophrenic angle
430
Where would you look for rotation in a CXR?
Look at medial ends of clavicle (but slight rotation is not important)
431
In which phase of respiration is a CXR usually done?
Inspiratory phase (patient holds breath)
432
What is the normal inspiratory lung volume visible on a CXR?
5th-7th anterior ribs at MCL
| Look at diaphragm, if curved cool, if flattened then increased lung volume
433
What might cause problems with incomplete inspiration visible on a CXR?
Big heart, increased lung markings
434
What might cause exaggerated expansion visible on a CXR?
Obstructive airway disease
435
What is penetration with regards to an X-ray?
The degree to which the X-rays have penetrated the body. Adequate penetration - vertebrae just visible through heart, complete left hemidiaphragm is visible. Digital manipulation often negates this
436
What is an artifact with regards to an X-ray?
External (iatrogenic) material which obstructs view, e.g. clothes (buttons!), hair, surgical/vascular lines, pacemaker
437
What are the different zones of a lung? (As used to describe an X-ray)
```
Left/right
Upper (above hilar)
Middle (Hilary level)
Lower (below hilar)
Zonesssss
```
438
Describe the systematic process you would go though to evaluate a chest x-ray
```
Patient demographics
Projection
Adequacy
Airway
Breathing
Circulation
Diaphragm (/dem bones)
Review areas
```
439
What does the AABCD stand for when analysing a CXR?
A - adequacy (RIP - rotation, inspiration, penetration)
A - airway (trachea, bronchi, hilar)
B - breathing (lungs (whole?), pleural spaces, lung interfaces)
C - circulation (mediastinum, aortic arch, pulmonary vessels (hilar), right heart border, right atrium, middle lobe interface, left heart border, left ventricle, lingual interface)
D - Diaphragm/Dem bones (free gas, nodules, fracture/dislocation, mass)
440
List some areas commonly missed when analysing a CXR
```
Apices - pneumothorax
Thoracic inlet - mass
Paratracheal stripe - mass/lymph nodes
AP window - lymph nodes
Hila - mass/collapse
Behind heart - mass
Below diaphragm - pneumoperitoneum/mass
Bones (all of them) - fracture, mass, missing
Edge of films
```
441
What is a silhouette sign?
Adjacent structures of differing density form a crisp 'silhouette', e.g. Heart nest to lung, white next to black. Loss of this contour can suggest/locate pathology.
442
What can the right heart border be referred to in a CXR?
RML
443
What can the left heart border be referred to in a CXR?
Lingula
444
What does a paratracheal stripe in a CXR suggest?
Mediastinal disease
445
Where is the aortic knuckle located?
Anterior mediastinum/upper lobe
446
What do you look for when analysing the chest wall in a CXR?
Lung/pleura/rib lesion
447
How do you look for a mediastinal shift in a CXR?
Check adequately centred image. Then look at trachea, cardiac shadows pushed or pulled?
448
What would a mediastinal push look like on a CXR?
Increased volume or pressure
449
What would a mediastinal pull look like on a CXR?
Decreased volume or pressure
450
List some specific CXR findings
Pneumothorax, pleural effusion, consolidation, space occupying lesion within lung, lobar collapse, estimate the cardiac index
451
What is pneumothorax?
Air trapped in the pleural space
452
What can cause pneumothorax?
Can be spontaneous, or as a result of underlying lung disease
453
What is the most common cause of pneumothorax?
Trauma, with laceration of the visceral pleura by a fractured rib
454
When is a pneumothorax said to be 'large'?
If lung edge measures more than 2cm from the inner chest wall at the level of the hilum
455
What is a tension pneumothorax?
Tracheal or mediastinal shift away from pneumothorax and depressed hemidiaphragm
456
What are the signs of a tension pneumothorax?
Visible pleural edge (lung markings not visible beyond this edge)
457
What is pleural effusion?
Collection of fluid in the pleural space.
458
What would a pleural effusion look like on a CXR?
Uniform white area. Loss of costophrenic angle. Hemidiaphragm obscured. Meniscus at upper border.
Beware supine CXR (laying down)
459
What is lobar lung collapse?
Volume loss within lung lobe
460
What might cause lobar lung collapse?
Luminal - aspirated foreign material, mucous plugging, latrogenic
Mural - bronchogenic carcinoma
Extrinsic - compression by adjacent mass
461
What are some generic findings of lobar lung collapse?
Elevation of the ipsilateral hemidiaphragm
Crowding of the ipsilateral ribs
Shift of the mediastinum towards the side of atelectasis
Crowding of pulmonary vessels
462
What is consolidation?
Filling of small airways/alveoli with stuff
463
If the lungs are filled with pus, what does this suggest the cause of consolidation is?
Pneumonia
464
If the lungs are filled with blood, what does this suggest the cause of consolidation is?
Haemorrhage
465
If the lungs are filled with fluid, what does this suggest the cause of consolidation is?
Oedema
466
If the lungs are filled with cells, what does this suggest the cause of consolidation is?
Cancer
467
What does consolidation look like on a CXR?
Dense opicification. Volume preserved/increased. Air bronchogram
468
What is a space occupying lesion?
Nodule >3cm
Mass >3cm
Single or multiple
469
What could be the cause of a space occupying lesion?
Malignant (primary, metastases), benign mass lesion, inflammatory, congenital, mimics (bone lesion, cutaneous lesion, nipple shadow)
470
What is a normal cardiac index?
Usually less than 50% width of chest wall
471
What's a key point to remember when analysing cardiac index?
Must be a PA image!
472
What is interstitial disease?
Disease effecting acini, alveolar lumen, bronchiolar lumen, bronchioles...
Broad discriptive term
473
What cells might be involved in interstitial disease?
Epithelial, endothelial, mesenchymal, macrophage, recruited inflammatory cells
474
What symptoms might be present for interstitial lung disease?
SOB, cough, chronic onset.
| Clubbing, right heart failure, cyanosis, tachycardia, tachypnoea, decreased chest movement, course crackles
475
What might cause interstitial lung disease?
Occupational, treatment related, connective tissue disease, immunological, idiopathic (mostly)
476
What is IPF? (With regards to respiratory disease)
Idiopathic pulmonary fibrosis
477
What is the prognosis of idiopathic pulmonary fibrosis?
Bad - mean survival 3yrs.
478
How is idiopathic pulmonary fibrosis usually diagnosed?
CT
479
What therapies are available for treatment of IPF idiopathic pulmonary fibrosis?
Pirfenidone and ninedanib - slows decline inf FVC, but some drug toxicity (only used if have to)
480
What is asbestosis?
Interstitial lung disease associated with asbestos
481
What can asbestos plaques cause?
Diffuse pleural thickening (benign asbestos pleural effusions BAPE)
482
What are some diseases associated with asbestos?
Mesothelioma, bronchogenic lung cancer, rounded atelectasis
483
What happens to the asbestos fibres?
They are needle like, and can lodge in pleura, causing disease
484
What treatment would you give for drug induced ILD?
Stop drug and give steroid instead (methotrexate, bleomycin, amiodarone, nitrofurantoin)
485
List some connective tissue diseases that have manifestations in the lung
```
Dermatomyositis/polymyositis
Sjögren's syndrome
Systemic lucid erythematosis
Scleroderma
Rheumatoid arthritis (lung symptoms may present before joint!)
```
486
What is sarcoidosis?
Often asymptomatic, or cough/rash. PFTs normal, restrictive, obstructive, mixed. Onset 20-80yrs.
Biopsy non-caseating granuloma
487
What is the treatment for sarcoidosis?
None, or steroids (but these have many side effects), methotrexate
488
What are the functions of the pleural space?
Allow movement of lung and chest wall
Coupling of chest wall and lung - inward lung recoil, outward chest wall recoil
Pleural fluid circulation
489
What is the innervation of the parietal pleura of the chest wall?
Somatic, sympathetic, and parasympathetic. Phrenic and intercostal nerves
490
What is the innervation of the visceral pleura of the chest wall?
No somatic innervation
| Sympathetic and parasympathetic
491
How might a patient describe pleuritic chest pain? (Parietal)
'Knife like'
| Worse with inspiration
492
What is the average turnover of pleural fluid?
~15ml a day
| Can increase to 300ml a day
493
How is pleural fluid produced?
Capillary filtration (starling forces), parietal pleura only
494
Where is pleural fluid reabsorbed?
Lymphatic drainage, parietal pleural lymphatic vis stomata on parietal pleural surface (mainly mediastinal, diaphragmatic regions)
495
What might cause pleural fluid accumulation?
```
Increased production/decreased absorption:
Lung interstitial fluid increase
Hydrostatic pressure increase
Permeability increase
Oncotic pressure decrease
Peritoneal fluid
Thoracic duct disruption
Lymphatic blockage
Elevated systemic venous pressure
```
496
What is the criteria for which, if one or more is met than fluid is classed as exudate?
Pleural fluid protein divided by serum protein is >0.5 (or protein is >30g/l)
Pleural fluid lactate dehydrogenase LDH divided by serum LDH is >0.6
Pleural fluid LDH >2/3 the upper limit of laboratory normal value for serum LDH (LDH>200)
497
How would you get some pleural fluid to test?
Thoracocentesis (ultrasound/CT guided)
498
What would you do with the sample following a thoracocentesis?
Analyse appearance, then get cell count and differential, protein, LDH, pH, glucose, cytology
499
If pleural fluid is transudate, what might be causing it?
Heart failure, cirrhosis, hypoalbunaemia
500
If pleural fluid is exudate, what might be causing it?
Infection, malignancy, RA, pulmonary embolism, asbestos
501
What is empyema?
```
pH <7.2
Glucose <3.4mmol
CT/USS - septations
May or may not be 'unwell'
Inflammatory markers may/may not be raised.
```
502
What are risk factors for empyema?
Risk factors - alcoholism, immunocompromise
503
What is the treatment for empyema?
Antibiotics +- drainage (surgical chest drain)
504
What usually causes haemothorax?
Usually traumatic or iatrogenic
505
What might be required for treatment of haemothorax?
Chest drain or surgical drain
506
What is chylothorax?
Milky appearance. Lymphatic interruption. lymphoma, iatrogenic
507
What is the commonest metastatic cancer to spread to the lungs?
Breast, renal, colon
508
What is the commonest primary malignancy of the lungs?
Mesothelioma (classic symptom = chest pain)
509
What are the symptoms of mesothelioma?
Chest pain (classic symptom)
Pain, breathlessness
CXR effusion, mediastinal pleural enlargement
History of asbestos exposure
510
What is primary pneumothorax?
In otherwise healthy people
| 'Spontaneous'
511
What is secondary pneumothorax?
Underlying lung disease e.g. Cancer, COPD
512
What is iatrogenic pneumothorax?
Due to procedures e.g. Central lines
513
What are the symptoms of pneumothorax?
Pleuritic chest pain, dyspnoea
514
When is a pneumothoax small?
<2cm
515
When is a pneumothorax large?
>2cm between lung margin and chest wall
516
What investigations might you do for a pneumothorax?
Plain CXR
517
What is the treatment of a patient with a small pneumothorax and no SOB?
Discharge and early outpatient review
518
What is the treatment of a patient with pneumothorax and SOB?
Intervention regardless of size of pneumothorax
519
What are the treatment options for a patient with pneumothorax and SOB?
Aspiration
Chest drain
Chemical pleurodesis (surgically glue peritoneum to wall) if recurrent
Open thoracotomy and pleuroectomy - lowest reoccurrence rate
520
When might you use aspiration to treat pneumothorax?
1st line treatment for primary pneumothorax requiring intervention
Used for small secondary pneumothorax in minimally breathless patients
521
When might you use a chest drain to treat a pneumothorax?
If aspiration fails to control symptoms, insert intercostal tube.
Recommended treatment for secondary pneumothorax
522
How is tension pneumothorax diagnosed?
Clinically
523
What are the signs of tension pneumothorax?
Cardiovascular compromise - tachycardia, hypotension
Decreased expansion with hyper resonance and absent breath sounds on side of pneumothorax
Shift of mediastinum to opposite side - trachea, apex beat
Hypoxaemia
524
What is the treatment of tension pneumothorax?
Don't wait for CXR! Cannula into affected side. O2. Intercostal chest drain. Respiratory/thoracic surgical referral - do not want to have a chance of it happening again (surgical pleurodesis)
525
How does having a pneumothorax effect flying?
Must wait at least 1 wk before can fly
526
When can you go diving, if you've had a pneumothorax?
Only if you have had a bilateral surgical pleuroectomy
527
Should you admit a patient with a secondary pneumothorax?
Yes for at least 24hrs
528
List some congenital forms of chest wall disease
Pectus deformities
Scoliosis
Kyphosis
Muscular dystrophy
529
List some aquired forms of chest wall disease
Trauma
Latrogenic
Ankylosing spondylitis
Motor neurone disease
530
What could cause tracheal shift - push to opposite side of diseased lung?
Massive effusion, large or tension pneumothorax
531
What could cause tracheal shift - pulled to same side as diseased lung?
Central collapse, unilateral fibrosis (e.g. Previous TB infection)
532
List some lung diseases which do not cause tracheal shift
Pneumonia, COPD, asthma, diffuse fibrosis
533
What could hyper resonant percussion be a sign of?
Pneumothorax
534
What could stony dull percussion be a sign of?
Pleural effusion
535
What could dull/impaired percussion be a sign of?
Consolidation
536
How would one describe normal breath sounds?
Normally vesicular
537
What could bronchial breath sounds be due to?
Consolidation (lobar pneumonia)
538
What could reduced intensity/absent breath sounds be due to?
Air (pneumothorax) or fluid (effusion) between chest wall and lung
539
When is vocal resonance increased?
When bronchial breathing is present (e.g. Lobar pneumonia)
540
When would vocal resonance be decreased?
Pneumothorax/pleural effusion
541
List the signs on examination of a patient with consolidation
Trachea: not shifted
Chest movements: reduced on effected side
Percussion: dull
Breath sounds: bronchial breath sounds. Conducted through consolidated lung to chest wall (sounds from large airways)
Vocal resonance: increased
Added sounds: crackles +- pleural rub
542
Describe the signs on examination of a patient with pleural effusion
Trachea: if large, shifted to opposite side (pushed by effusion)
Chest movements: reduced on effected side
Percussion: stony dull over effusion
Breath sounds: vesicular - reduced intensity/absent on affected side
Vocal resonance: reduced
Added sounds: none
543
Describe what you would find on examination of a patient with pneumothorax
Trachea: if large or tension, trachea shifted to opposite side (away from PNX)
Chest movements: reduced on effected side
Percussion: hyper resonant on affected side
Breath sounds: vesicular, reduced intensity. (Air between chest wall and lung)
Vocal resonance: decreased
Added sounds: none
544
What is a lobar collapse?
Due to an obstruction of a large airway, air in that part of lung is gradually absorbed/diffuses away - 'central' cause of lung collapse. Lung is tethered to pleura, so is pulled towards it, bringing the trachea/mediastinum with it.
545
Describe what you would find on examination of a patient with lobar collapse
Trachea shift: towards effected side. Subatmospheric pleural pressure pulls collapsed lung and mediastinum to affected side
Chest movements: reduced on effected side
Percussion: normal (or dull) over affected lobe
Breath sounds: reduced or absent over effects lobe
Vocal resonance: reduced
Added sounds: none
546
Describe what you would find on examination of a patient with localised lung fibrosis
Trachea: pulled by contracting fibrous tissue towards effected side
Chest movements: reduced on effected side
Percussion: normal
Breath sounds: vesicular
Added sounds: crackles
Vocal resonance: normal/increased
547
Describe what you would find on examination of a patient with diffuse lung fibrosis
```
Trachea: central
Chest movements: reduced on both sides symmetrically
Percussion: normal
Added sounds: (fine) crackles
Vocal resonance: normal/increased
```
548
Describe what you would find on examination of a patient with COPD or asthma
May find a barrel chest on inspection
Trachea: central
Chest movements: reduced symmetrically on both sides
Percussion: resonant
Breath sounds: vesicular
Added sounds: prolonged expiration and wheezes
Vocal resonance: normal
549
What is COPD?
Loss of elastic tissue
Airways obstruction and reduced elastic recoil - hyperinflated lung (barrel chest)
FEV1/FVC <70%
FVC not reduced much
Low diffusion capacity (due to less surface area)
550
How does fibrosis effect lungs?
Increase of fibrous tissue
Less compliant - harder to stretch, smaller lungs
No airway obstruction
FEV1/FVC >70%
FVC markedly reduced
Low diffusion capacity (due to thickened membrane)
551
What might cause pleuritic chest pain?
Lobar pneumonia, pulmonary embolism, infarction, pneumothorax
552
What is dyspnoea?
An awareness that it is taking an abnormal amount of effort to breath (see MRC dyspnoea scale to gauge how bad it is)
553
What might a cough lasting <3wk be due to?
Upper/lower respiratory tract infection,
554
What might a cough lasting >3wk be due to?
COPD, asthma, cancer, medication (e.g. ACE inhibitors)
555
What is haemoptysis?
Coughing up blood (from lungs)
556
What is haematemesis?
Throwing up blood (from GIT)
557
What might cause haemoptysis?
Bronchitis, bronchial carcinoma, pneumonia, pulmonary infection, tuberculosis
558
What might cause a wheeze?
Asthma, COPD, foreign body...
559
Is strider normally on inspiration or expiration?
Inspiration
560
Is wheeze normally on inspiration or expiration?
Expiration
561
What might cause hoarseness of voice?
Transient infection of vocal cords, vocal cord tumour, recurrent laryngeal nerve palsy (left side has a particularly long course, could be damaged by bronchial carcinoma)
562
What drugs might cause a cough?
ACE inhibitors
563
What drugs might cause a wheeze?
Beta blockers
564
What drugs might cause a pulmonary embolism?
Oestrogens
565
What drugs might cause fibrotic lung changes?
Amiodarone
566
What is a barrel chest?
Increased AP diameter
567
What is a pigeon chest?
Prominent sternum/costal cartilage
568
What is a funnel chest?
Depression of lower end of sternum
