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Flashcards in Respiratory Deck (68):
1

A patient's arterial blood gas analysis gives the following results:
pO2 10 kPa/75mmHg (11.3-12.6 kPa)
pCO2 7 kPa/52 mmHg (4.7-6.0 kPa)
pH 7.47 (7.36-7.44)
Bicarbonate 37 mmol/L (20-28)
Which of the following is the most likely cause?
(Please select 1 option)
Acute exacerbation of chronic obstructive pulmonary disease
Chronic hyperventilation syndrome
Diabetic coma
Pulmonary embolism
Pyloric obstruction

These results demonstrate a metabolic alkalosis and there is respiratory compensation with an elevation of pCO2.

Consequently, pO2 is slightly low.

The most probable cause out of those given is pyloric stenosis.

2

A Metabolic acidosis - acute, normal oxygenation
B Metabolic acidosis - acute with hypoxaemia
C Metabolic acidosis - compensated, normal oxygenation
D Metabolic alkalosis - acute, normal oxygenation
E Metabolic alkalosis - acute with hypoxaemia
F Metabolic alkalosis - compensated, normal oxygenation
G Normal blood gases
H Normal ventilation with hypoxaemia
I Respiratory failure - acute
J Respiratory failure - compensated, normal oxygenation
K Respiratory failure - compensated with hypoxaemia
For each of the following blood gas results select the most appropriate designation from the list of options.
The line labelled 'oxygen concentration' represents the concentration of oxygen that each individual is inhaling.
Normal values
PaO2 12.0-14.7 kPa
PaO2 90-110 mmHg
PaCO2 4.5-6.0 kPa
PaCO2 34-45 mmHg
pH 7.36-7.44
H+ molarity 35-45 nmol/l
Bicarbonate 24-30 mmol/l

pO2 12.9 kPa (97 mmHg)
pCO2 5.8 kPa (44 mmHg)
pH 7.24
H+ molarity 57 nmol/l
Bicarbonate 18 mmol/l
Base excess -7 mmol/l
Oxygen concentration 40%

pO2 6.7 kPa (50 mmHg)
pCO2 10.1 kPa (76 mmHg)
pH 7.38
H+ molarity 42 nmol/l
Bicarbonate 42.4 mmol/l
Base excess +14 mmol/l
Oxygen concentration 21%

pO2 14.3 kPa (108 mmHg)
pCO2 6.3 kPa (48 mmHg)
pH 7.52
H+ molarity 30 nmol/l
Bicarbonate 39 mmol/l
Base excess +14 mmol/l
Oxygen concentration 30%

pO2 4.7 kPa (35 mmHg)
pCO2 12.7 kPa (95 mmHg)
pH 7.12
H+ molarity 76 nmol/l
Bicarbonate 29.5 mmol/l
Base excess -4 mmol/l
Oxygen concentration 21%

pO2 16.3 kPa (122 mmHg)
pCO2 7.5 kPa (56 mmHg)
pH 7.26
H+ molarity 55 nmol/l
Bicarbonate 24.1 mmol/l
Base excess -2 mmol/l
Oxygen concentration 75%

Metabolic acidosis - acute with hypoxaemia
The low pH with low bicarbonate indicates a metabolic acidosis, and the low normal O2 on inspired [O2] indicates hyperaemia.

Respiratory failure - compensated with hypoxaemia
This is the typical feature of a corrected respiratory failure with hypoxaemia. The PaO2 is low, the PaCO2 is high, with raised bicarbonate indicating renal correction and a high base excess.

Metabolic alkalosis - acute, normal oxygenation
Metabolic alkalosis, for example in a patient with severe vomiting, is characterised by a high pH, high bicarbonate and a raised base excess. In an effort to compensate, the respiratory drive decreases and hence the PCO2 begins to rise.

Respiratory failure - acute
Hypoxia, hypercapnia and acidosis with a normal bicarbonate, indicate an acute respiratory failure, for example in massive pulmonary embolism.

Respiratory failure - acute
Here is an acidosis with a normal bicarbonate, and hypercapnia, on high flow O2. This is the picture of acute respiratory failure often found in patients with chronic obstructive airway disease who have lost their hypoxic drive and have been given high concentrations of O2.

3

Chest signs
A Asthma
B Bronchial carcinoma
C Bronchiectasis
D Chronic bronchitis
E Emphysema
F Pleural effusion
G Pneumonia
H Pneumothorax
I Pulmonary fibrosis
J Pulmonary oedema

Select the most appropriate diagnosis for a 55-year-old male who presents with dyspnoea and the following signs:
Temperature 36.7C, clubbing of fingers, respiratory rate 15/min, JVP not visible, trachea central, percussion note resonant with bronchial breath sounds overlying the left midzone.

Temperature 39C, respiratory rate 30/min, JVP not visible, trachea central, percussion note dull over the left midzone and accompanying wheeze and bronchial breath sounds.

Temperature 36.5C, respiratory rate 28/min using accessory muscles of respiration, JVP raised 5 cm, trachea central, percussion note resonant and widespread inspiratory basal crackles.

Clubbing would be associated with bronchial carcinoma, pulmonary fibrosis and bronchiectasis from the choices offered.

In the case scenario, the signs of consolidation in the left midzone suggest an underlying bronchial carcinoma as the most likely explanation.

High temperature, increased respiratory rate and signs of consolidation in the left midzone suggest a pneumonic consolidation. Typically a lobar pneumonia would be caused by Pneumococcus.

Normal temperature, increased respiratory rate, raised JVP, cyanosis and basal crackles would suggest cardiac failure and pulmonary oedema as the likely diagnosis. Other features that may be expected on auscultation of the heart include a third heart sound signifying rapid ventricular diastolic filling.

4

The diffusion capacity of the lung as assessed by carbon monoxide transfer is raised in all but which of the following states?
(Please select 1 option)
Altitude
Asthma
Exercise
Polycythaemia
Post pneumonectomy

Following lung resection (and in the presence of interstitial lung disease) the diffusion capacity is reduced and there is a reduced alveolar volume.

In emphysema, pulmonary vascular disease and anaemia, the diffusion capacity is reduced but the alveolar volume is increased.

In the other conditions listed above the diffusion capacity is elevated.

5

By which of the following is peripheral oxygen consumption decreased ?
(Please select 1 option)
Catecholamines
Exercise
Hypothermia
Infection
Thyroxine

Hypothermia

Hypothermia together with rest and paralysis decrease oxygen consumption whereas the other factors listed increase peripheral oxygen consumption.

This phenomenon is taken advantage of in open heart and neurological surgery and in organ preservation.

6

A 60-year-old man undergoes a lobectomy for bronchial carcinoma.
During the follow-up he undergoes respiratory function testing.
Which of the following factors would not be expected to fall post-operatively?

Dead space
Expiratory reserve volume
Forced vital capacity
Inspiratory reserve volume
Tidal volume

Tidal volume

The tidal volume increases as a compensatory mechanism for the reduced surface area for oxygen exchange as does the respiratory rate.

The remaining lung volumes all decrease following pneumonectomy.

7

A 56-year-old lady undergoes a lobectomy for adenocarcinoma of the lung.
On the second postoperative day she is noted to be tachypnoeic and has oxygen saturations of 92% on 28% oxygen.
Which of the following factors is not contributing to her respiratory dysfunction?
(Please select 1 option)
Abdominal ileus
Anaesthetic agents IncorrectIncorrect answer selected
Poor pain control
Preoperative smoker
Prone position

All patients should be nursed prone if at all possible as this aids gaseous exchange whereas a supine position increases intra-abdominal pressure and further exacerbates the respiratory dysfunction.

The other factors listed are detrimental.

The effects of different anaesthetic agents are numerous and include

Reduced central response to hypercapnia
Reduced mucociliary clearance
Increased production of more viscous secretions.

8

A 24-year-old man is seen in pre-clerking prior to panproctocolectomy for familial adenomatous polyposis.
His past medical history also includes asthma for which he takes regular inhalers. Preoperative respiratory function tests are requested.
Which of the following changes is likely to be observed?
(Please select 1 option)
Decreased functional residual volume
Increased FEV1/FVC ratio
Reduced FEV1/FVC ratio CorrectCorrect
Reduced forced vital capacity
Reduced total lung capacity

This is characteristic of an obstructive disease such as asthma.

In asthma the forced vital capacity (FVC) is usually normal (but may be slightly reduced in severe cases) and it is the fall in forced expiratory volume in one second (FEV1) that is most important.

Furthermore, there is usually a positive bronchodilator response (greater than 12% improvement) in the FEV1/FVC ratio in obstructive disease.

The forced respiratory volume (FRV) is usually increased in asthma due to air trapping.

9

A 70-year-old retired coal miner attends for a TURP.
The anaesthetist examines his chest, is concerned about his findings, and requests lung function tests.
Which of the results below is out of character with the condition?

Pneumoconiosis is associated with fibrosis and is, as such, an example of a restrictive pulmonary disease.

In restrictive disease lung volumes are reduced and the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio is consequently usually increased.

The respiratory rate is increased to try and compensate for the reduced volumes.

10

You are carrying out a pleural aspiration for a patient with a persisting post-operative effusion.
Which of the following structures do you want the needle to avoid?
(Please select 1 option)
External intercostal muscle
Internal intercostal muscle
Parietal pleura
Transversus thoracis muscle
Visceral pleura

The visceral layer of pleura is adherent to the lung and should not be pierced during pleural aspiration. This will cause damage to the lung.

However, all of the other structures will be pierced by the needle as you perform a pleural aspiration.

11

A 34-year old lady with asthma attends the Emergency department with laboured breathing. You note that she is using accessory muscles of respiration.
Which of the following is an accessory muscle of respiration?
(Please select 1 option)
External intercostal
Internal oblique
Serratus anterior
Subscapularis
Trapezius

The accessory muscles of respiration are used in deep inspiration and include:

Sternocleidomastoid
Scalenus anterior, medius and posterior
Serratus anterior, and
Pectoralis major and minor.
Trapezius is not attached to the ribs so cannot be an accessory muscle of respiration.

There appears to be no clear agreement on the number of muscles that can be considered 'accessory'. Any muscle that can affect chest expansion is included in some lists.

12

In an anatomy practical class you are asked to distinguish between right and left lungs on the basis of their anatomical features.
Which of the following statements is correct regarding the right lung?
(Please select 1 option)
Has a lingular segment
Has a longer bronchus than the left lung
Has a single pulmonary vein within the hilum
Has no middle lobe
Has oblique and horizontal fissures

The right lung is divided into upper, middle and lower lobes by oblique and horizontal fissures.

The lingular segment is the left lung's equivalent of the middle lobe.

The right bronchus is shorter and wider than the left bronchus and two pulmonary veins return blood from each lung.

13

You are arranging pre-operative investigations for a patient who needs a hemiarthroplasty after sustaining a fractured neck of femur. The patient smokes and is known to have chronic obstructive airway disease.
Arterial blood gases show raised CO2 levels, reduced O2 levels, a reduced pH, and a raised bicarbonate.
What is the explanation?
(Please select 1 option)
Metabolic acidosis
Metabolic alkalosis
Partially compensated respiratory acidosis
Uncompensated respiratory acidosis
Uncompensated respiratory alkalosis

The reduced pH and elevated CO2 levels indicate a respiratory acidosis.

The plasma bicarbonate concentration increases to compensate for the increased hydrogen ion concentration. The pH is not returned to normal so there is only partial compensation.

Respiratory acidosis is typically caused by a reduction in ventilation or ventilation/perfusion mismatch. This can occur with chronic obstructive pulmonary disease (COPD), asthma and chest wall injuries.

14

ou are called to see a patient on the ward who is short of breath and complaining of chest pain.
She has recently had a total knee replacement. You suspect she might have had a pulmonary embolism.
An ECG has been performed.
Which of the following are typical ECG findings in pulmonary embolism?
(Please select 1 option)
Bradycardia
Left bundle branch block
S1Q1T3
S3Q3T3
Tachycardia

ECG changes usually occur only with large pulmonary emboli.

The characteristic changes include:

Tachycardia
A right ventricular strain pattern with inverted T waves in V1-V4
Right bundle branch block
S1Q3T3 pattern and
Transient arrhythmias, such as atrial fibrillation.

15

A 45-year-old woman presents to the Emergency Department with a 48 hour history of right upper quadrant abdominal pain, dyspnoea, non-productive cough and high temperature. She says that the pain is radiating to her right shoulder tip.
She had undergone repair of a perforated duodenal ulcer three weeks ago. On examination, her temperature is 39.3°C and she is acutely tender over the right hypochondric region. Chest x ray reveals a right sided pleural effusion.

Subphrenic abscesses usually arise as a result of direct contamination after surgery especially of the biliary tract, duodenum or stomach, or a perforated viscus. The other causes include infections or trauma to the liver and gall bladder.

The subphrenic space is in direct contact with the para-colic gutter, thereby allowing peritoneal contamination such as bile, blood or bowel contents to spread. Clinical features include

pyrexia (sometimes swinging)
anorexia
loss of appetite
loss of weight.
Chills and rigors may be seen in some patients.

Diaphragmatic irritation may affect the right lung, which may result in chest pain, dyspnoea and non-productive cough. Basal atelectasis, pneumonia and pleural effusion are also recognised complications which cause percussion dullness and decreased breath sounds on the affected side.

An ultrasound scan is the investigation of choice to diagnose subphrenic abscess, and, if an abscess is identified, ultrasound guided percutaneous drainage catheter may be placed at the same time.

However, if the abscess is diagnosed early (but no air fluid level) it may then be treated with broad spectrum antibiotics for a short duration.

16

You are asked to see a patient who attends the emergency department with shortness of breath.
The chest x ray shows right lower lobe consolidation.

Which of the following features should prompt you to consider admission to hospital?

Audible bronchial breathing
A PaO2 of 9.8 kPa (11-13)
A respiratory rate of 32/min
A SaO2 of 95%
A white cell count of 16.8x109/l (4-10)

The British Thoracic Society guidelines for community acquired pneumonia in adults recommend use of the CURB-65.

This is a 5-point score, one point for each of

Confusion
Urea more than 7 mmol/l
Respiratory rate 30/min or more
Systolic Blood pressure below 90 mmHg (or diastolic below 60 mmHg)
Age 65 years or older.
If the CURB score is 1-2 then risk of death is increased and hospital admission should be considered.

A CURB score of 3 or more puts the patient at high risk of death and hospital admission is warranted.

17

A 19-year-old male attends the Emergency department complaining of a sudden left-sided chest pain followed by dyspnoea. These symptoms developed whilst playing football.
Which of the following investigations is most likely to provide a definitive diagnosis?

Blood gases
Chest x ray
Echocardiogram
Electrocardiogram (ECG)
Pulmonary function tests

CXR
The history is suggestive of a pneumothorax, and of the available investigations a chest x ray is the only test which will provide a definitive diagnosis.

ECG would be unlikely to reveal any abnormality and blood gases would be most likely to reveal a highish O2 with lowish CO2 in the absence of any appreciable respiratory compromise.

18

A 22-year-old golf course groundsman develops sudden onset of breathlessness and right-sided chest pain whilst maintaining the 18th hole. He is rushed to hospital, but his condition worsens when being examined by a junior doctor.
She reported finding a trachea that was deviated to the left, and hearing very distant breath sounds over his right lung. Following the intervention of a senior doctor, his condition improves rapidly.
What is the most probable diagnosis?

Myocardial infarction
Pericarditis
Pneumonia
Pulmonary embolism
Tension pneumothorax

Tension pneumothorax

Sudden onset of chest pain and respiratory distress in a previously fit young man should alert one to the diagnosis of pneumothorax.

Tales of patients who developed a clinically obvious tension pneumothorax in hospital are told frequently, so it is best to be able to recognise one if it occurs while you are actually examining the patient!

19

A 45-year-old, overweight shop assistant is admitted to hospital with sudden onset of breathlessness and right posterior lower chest pain three weeks after undergoing right total hip replacement surgery.
She has a past medical history of bronchiectasis and asthma, but denies any recent change in sputum colour or quantity.
Oxygen saturation is 89% on air, but rises to 95% on (35%) oxygen. She is apyrexial. Chest examination reveals coarse leathery crackles at both lung bases.
Peak flow rate is 350 L/min and chest radiograph shows bronchiectatic changes, also at both lung bases. Full blood count is normal.
What is the most appropriate investigation to conduct next?

Blood cultures
CT-pulmonary angiography
Echocardiogram
Full blood count
Ventilation/perfusion scan

CTPA

Computerised tomography (CT) pulmonary angiography is the investigation of choice in this patient who almost certainly has a pulmonary embolism.

Ventilation perfusion scan is not ideal in a patient with chronic lung disease, because the scan can be difficult to interpret.

20

A 12-year-old girl presents with left ear pain and fever, worsening over the past three days. Today her mother has noted a whitish creamy discharge from the ear canal.
She was born at 38/40 gestation weighing 3.8 kg and there were no neonatal problems. She is fully immunised. She trains regularly in a swimming team.
On examination she has a temperature of 38.2°C and has a red left tragus. This is exquisitely tender, and examination of the drum is impossible because of the pain and creamy thin discharge. She has shotty tender posterior cervical glands.
What is the most likely diagnosis?

Group A streptococcal pharyngitis
Mastoiditis
Otitis externa
Otitis media, acute
Otitis media, recurrent

The history suggests an acute otitis externa. The tight adherence of skin to the underlying perichondrium and periosteum make the pain worse than the degree of inflammation would suggest.

An ear swab culture should be sent and neomycin and colistin/polymyxin ear drops commenced. This covers the common Gram positive and Gram negative bacteria usually responsible.

21

A 7-year-old girl presents with right ear pain and fever, worsening over the past few days. Symptoms began seven days ago with severe ear pain and fever, which was treated with paracetamol. The following morning the pain resolved and a purulent discharge mixed with blood was noted on her pillow. Four days later the pain is throbbing and her ear is tender.
She was born at term weighing 3.68 kg and there were no neonatal problems. She is fully immunised, and there is no FH/SH of note.
On examination she has a fever to 39.7°C, and her right ear is displaced downwards and forwards. She is extremely tender behind the right ear, and has a purulent discharge from the ear canal. Her pulse is 100/min and respiratory rate is 15/min.
What is the most likely diagnosis?

Cholesteatoma
Mastoiditis CorrectCorrect
Otitis media with effusion
Otitis media, acute
Otitis media, recurrent

Mastoiditis

The history suggests acute otitis media with perforation, followed by acute mastoiditis (acute mastoid osteitis).

This can be confirmed by CT scan of the mastoid.

Pneumococcus and H. influenzae are the commonest cause.

Most resolve with antibiotics, but some require surgical drainage.

22

Carcinoid tumours of the lung (bronchial adenomas) originate from which of the following cell types?

Ciliated cell
Clara cell
Kulchitsky (K) cell
Mucus (goblet) cell
Type 2 alveolar cell

Kulchitsky (K) cell

Carcinoid tumours (so called argentafinomas as they take up silver) are neuroendocrine cells and are derived from the K cells in the lung.

23

Which one of the following is true regarding acute pulmonary embolism?

A normal ECG excludes the diagnosis
Embolectomy is more effective than thrombolysis in improving survival IncorrectIncorrect answer selected
Heparin is as effective as thrombolytic therapy
The presence of hypoxaemia is an indication for thrombolysis
Thrombolysis administered through a peripheral vein is as effective as through a pulmonary artery catheter

Embolectomies are rarely done nowadays due to the excellent results with thrombolysis.

Thrombolytic therapy is reserved for those with severely compromised circulation (equally effective through peripheral vein or via catheter in pulmonary artery).

Heparin reduces risk of further embolism (anticoagulant) and reduces pulmonary vasoconstriction.

24

Blood gas analysis

A Metabolic acidosis - acute, normal oxygenation
B Metabolic acidosis - acute with hypoxaemia
C Metabolic acidosis - compensated, normal oxygenation
D Metabolic alkalosis - acute, normal oxygenation
E Metabolic alkalosis - acute with hypoxaemia
F Metabolic alkalosis - compensated, normal oxygenation
G Normal blood gases
H Normal ventilation with hypoxaemia
I Respiratory failure - acute
J Respiratory failure - compensated, normal oxygenation
K Respiratory failure - compensated with hyperaemia

For each of the following blood gas results, select the most appropriate designation from the list of options.

The line labelled oxygen concentration represents the concentration of oxygen that each individual is inhaling.

Normal values are:
PaO2 12.0-14.7 kPa (90-110 mmHg)
PaCO2 4.5-6.0 kPa (34-45 mmHg)
pH 7.36-7.44
H + molarity 35-45 nmol/L
Bicarbonate 24-30 mmol/L

pO2 10.0 kPa (80 mmHg)
pCO2 5.8k Pa (44 mmHg)
pH 7.24
H+ molarity 57 nmol/L
Bicarbonate 18 mmol/L
Base Excess −7 mmol/L
Oxygen concentration 40%

pO2 6.7 kPa (50 mmHg)
pCO2 10.1 kPa (76 mmHg)
pH 7.38
H+ molarity 42 nmol/L
Bicarbonate 42.4 mmol/L
Base excess +14 mmol/L
Oxygen concentration 21%

pO2 14.3 kPa (108 mmHg)
pCO2 6.3 kPa (48 mmHg)
pH 7.52
H+ molarity 30 nmol/L
Bicarbonate 39 mmol/L
Base excess +14 mmol/L
Oxygen concentration 30%

pO2 4.7 kPa (35 mmHg)
pCO2 12.7 kPa (95 mmHg)
pH 7.12
H+ molarity 76 nmol/L
Bicarbonate 29.5 mmol/L
Base excess −4mmol/L
Oxygen concentration 21%

pO2 16.3 kPa (122 mmHg)
pCO2 7.5 kPa (56 mmHg)
pH 7.26
H+ molarity 55 nmol/L
Bicarbonate 24.1 mmol/L
Base excess −2 mmol/L
Oxygen concentration 75%

The low pH with low bicarbonate indicates a metabolic acidosis, and the low normal O2 on inspired [O2] indicates hypoxaemia. This may occur with poisoning and associated respiratory failure.

This is the typical feature of a corrected respiratory failure with hypoxaemia. The PaO2 is low, the PaCO2 is high, with raised bicarbonate indicating renal correction and a high base excess.

Metabolic alkalosis, for example in a patient with severe vomiting, is characterised by a high pH, high bicarbonate and a raised base excess.

There is a type 2 respiratory failure with hypoxia, hypercapnia and acidosis with a normal bicarbonate, indicating an acute respiratory failure, for example in severe asthma or pneumonia.

There is an acidosis with a normal bicarbonate, and hypercapnia, on high flow O2. This is the picture of acute respiratory failure often found in patients with chronic obstructive airways disease who have lost their hypoxic drive and have been given high concentrations of O2.

25

A 27-year-old female with adult respiratory distress syndrome (ARDS) is ventilated on intensive care.
Her inspired oxygen is 100%, positive end expiratory pressure is 15 cmH2O and peak airway pressure is 40 cmH2O.
Her arterial blood gas shows:
PaO2 6 kPa (11.3-12.6)
PaCO2 6.9 kPa (4.7-6.0)
SpO2 88% (>92%)
What treatment has been shown to decrease mortality in this patient group?
(Please select 1 option)
High frequency oscillatory ventilation (HFOV)
Increasing tidal volume and respiratory rate on the ventilator
Inhaled nitric oxide therapy
Prone position
Extracorporeal membrane oxygenation (ECMO)

This lady is on maximal ventilatory therapy but is still hypoxic. Her high CO2 is a reflection of permissive hypercapnia to prevent overdistension of the lungs with high tidal volumes.

Treatment of these patients used to be extremely difficult, with no significant improvement in prognosis seen will any technique. However, in 2010 the CESAR trial demonstrated a significant increase in survival without significant disability with the use of extracorporeal membrane oxygenation (ECMO).

ECMO involves connecting a patient's circulation to an external oxygenator and pump, via a catheter placed in the right side of the heart. It requires the continuous infusion of anticoagulant, and as such bleeding is the most commonly associated complication. Infection and haemolysis are also a risk.

A recent study1 published in the NEJM concluded that prone positioning improved outcome in severe ARDS. However, it is only one study in a controversial area. There are a number of studies, including one by the same group, which have not shown a mortality benefit (and others which show a detrimental effect on mortality). Prone positioning is therefore not yet widely accepted in clinical practice, although this may change in the future. For the purpose of the MRCP (where there are single best answers), ECMO remains the correct answer.

26

A 25-year-old male is involved in a high speed road traffic accident and after extraction from his car is brought to the Emergency department. On initial primary survey, he is triple immobilised. He is making slightly confused conversation.
Initial observations reveal a tachycardia of 120 bpm, and a systolic blood pressure of 90 mmHg. He has a respiratory rate of 30 and his chest is dull to air entry on the right hand side. He is tender over his right upper quadrant on abdominal examination.
How much of his circulating blood volume is he likely to have lost?
(Please select 1 option)
Nil
Up to 15%
15% to 30%
30% to 40%
Greater than 40%

The most common cause of shock in the trauma patient is haemorrhage.

The patient has decreased blood pressure and a tachycardia which means that he is in at least class III shock, signifying a blood loss of 1500 to 2000 ml, or approximately 30 to 40% of circulating blood volume.

27

An otherwise healthy 32-year-old man was the driver of a car involved in a high speed RTA three days ago.
He has sustained a closed fracture of his femur which has been treated surgically with an intramedullary nail, as well as fractures of his right clavicle and left radius. He was managed according to ATLS protocol when he attended the emergency department.
On examination he is acutely short of breath and has a temperature of 37.5oC. The patient seems confused when you speak to him, and as you examine him, you note petechial haemorrhages.
What do you think is the most likely diagnosis?

Asthma attack
Chest infection
Fat embolism CorrectCorrect
Pulmonary embolism
Tension pneumothorax

The two diagnoses which should be considered first in this scenario are pulmonary embolism and fat embolism.

Although the patient is at high risk of pulmonary embolism, and appropriate measures should be undertaken to reduce this, the clinical scenario is more suggestive of fat embolism. Fat embolism is thought to occur as a result of release of lipid globules from damaged bone marrow fat cells. Another mechanism that has been suggested is the increased mobilisation of fatty acids peripherally.

The effects that are seen clinically depend on what part of the microvasculature is affected by the lipid globules.

Pulmonary symptoms are caused by ventilation perfusion mismatch.

Confusion (cerebral effects) may be seen, as well as a petechial rash caused by capillary damage in the skin.

28

A 45-year-old gentleman has recently bought a motorcycle. He crashes it on his first journey and is brought to the emergency department, where a trauma call is put out. He has full spinal immobilisation.
Initial observations reveal that he has a blood pressure of 92 mmHg systolic and a pulse of 120 bpm. He gasps for breath. On examination, you find that his trachea is deviated and he has no breath sounds on the right hand side.
What is the next step in your management?

Call for senior help
Chest drain insertion
Fluid bolus challenge
Immediate chest x ray
Needle decompression

The patient is displaying signs of a tension pneumothorax. This requires immediate treatment without delay.

The patient should have a needle inserted into the second intercostal space in the midclavicular line.

This is a clinical diagnosis and the treatment should take place before a chest x ray is taken.

29

A 17-year-old boy has stolen a car and crashes it at approximately 60 mph into a brick wall. He is extracted by the fire service and brought to the Emergency department.
He is triple immobilised and is haemodynamically stable. He is complaining of some neck pain and chest pain, but otherwise does not seem to have any other injuries.
A chest x ray and pelvic x ray are taken as adjuncts to the primary survey. The initial chest x ray shows a widened mediastinum.
What should be the next step in the patient's management?
(Please select 1 option)
Admit to ward for observation
Chest drain insertion
Computed tomography (CT) of the patient's chest
Emergency department thoracotomy
Wait one hour then repeat chest x ray

The rapid acceleration-deceleration injury force is the classic mechanism for traumatic aortic disruption and when this patient first presents to the Emergency department, there should be a high index of suspicion for this injury.

A widened mediastinum may be the only clue on the initial chest film. This can be difficult to assess with the quality of the PA film obtained.

As the patient is haemodynamically stable a CT scan of the patient's chest would be the next most appropriate step. He should have 2 large bore IV lines in place and a doctor should go with the patient to the scanner.

30

A 42-year-old male falls from a height whilst at work. He sustains an injury to his chest.
On examination, he is tachypnoeic, with absent breath sounds on the right hand side and a central trachea. He is given high flow oxygen. A chest x ray reveals multiple fractured ribs on the right hand side and a large pneumothorax. A decision is made for a chest drain to be inserted.
What are the landmarks for where the drain should be inserted?

Anterior to mid-axillary line, 2nd intercostal space
Anterior to mid-axillary line, 5th intercostal space
Mid-clavicular line, 2nd intercostal space
Mid-clavicular line, 5th intercostal space
Posterior to mid-axillary line, 4th intercostal space

The mid-clavicular line, second intercostal space would be the site for emergency needle decompression of a tension pneumothorax.

The landmarks for chest drain insertion are anterior to the mid-axillary line in the fifth intercostal space.

31

A 55-year-old man is cycling to work. He is hit by a van and knocked off his bicycle. He is brought to his local emergency department, where he complains of severe abdominal pain.
He has a pulse rate of 120 and has a blood pressure of 80 mmHg systolic. His chest is clear on examination, but he is very tender over his left upper quadrant in his abdomen.
Chest x ray and pelvic x ray are unremarkable. Intravenous access is obtained and fluids commenced.
What should be the next step in his management?
(Please select 1 option)
CT scan of his abdomen
Laparotomy in theatre
Left sided chest drain insertion
Ongoing fluid resuscitation and await response
Plain x ray films of abdomen

Laparotomy

The patient has a definite source of bleeding which must be stopped to prevent death.

The history strongly suggests that his abdomen is the source for his bleeding. He should therefore be taken to theatre to proceed to laparotomy.

Haemodynamically unstable patients should not be taken for CT scanning.

32

A 16-year-old male is involved in a fight whilst drunk on Saturday night. He is initially lucid, but his Glasgow coma scale score rapidly decreases and a CT scan of his head is immediately performed. This reveals an extradural haematoma. He is referred to the on call neurosurgery team for evacuation of the haematoma.
As the cranium is a fixed volume box, the total volume of its contents must remain the same. The presence of an expanding haematoma can therefore lead to a decrease in cerebral blood flow.
What is this explanation called?
(Please select 1 option)
Glasgow head injury rule
Kernohan's syndrome
Monro's law
Monro-Kellie doctrine
Sylvius' law

Monro-Kellie doctrine

The Monro-Kellie doctrine states that the total volume of the entire cranium must remain constant as the skull is a fixed volume. Therefore, a rapidly expanding haematoma needs urgent evacuation to prevent pressure on other structures.

Of the other options only Kernohan's syndrome exists. The Kernohan-Woltman syndrome (1929) is a false localising ipsilateral hemiparesis. It is caused by transtentorial herniation: the free edge of the tentorium then compresses the contralateral crus cerebri.

33

A 26-year-old man is assaulted, receiving direct blows to his head. He is brought to his local Emergency department where he is assessed by the casualty SHO.
On initial examination, he opens his eyes to speech, reaches up as you put pressure on his sternum, and answers questions with confused conversation.
What is his Glasgow coma scale (GCS) score?
(Please select 1 option)
9
10
11
12
13

Accurate recording of the patient's GCS is necessary so that any further change can be accurately assessed and information can be easily communicated to other health care professionals.

In this case, the patient scores:

3 out of 4 as he opens his eyes to voice
5 out of 6 as he localises to pain
4 out of 5 as his conversation is confused

34

A 32-year-old patient is involved in a severe road traffic accident.
On arrival in a district general hospital Emergency Department, he has a GCS of 3 and is intubated. He is taken to the CT scanner, where a right-sided subdural and a left-sided extradural haematoma plus multiple contusions are noted. The regional neurosurgery unit are contacted but no surgical intervention is advised and he is placed in the ITU. A few days later, his condition on ventilator has not improved and he is assessed for brainstem death.
Which of the following is a criterion for the diagnosis of brainstem death?
(Please select 1 option)
Core temperature of 36°C
Glasgow coma score of 3
No response to adrenaline injection
No spontaneous ventilatory effort
Pulse of greater than 120

Brain stem death is diagnosed when the patient is deeply unconscious (GCS of 3) due to a known and irreversible structural injury.

There must be

Fixed and non-reactive pupils
No spontaneous ventilatory effort and
Absent brainstem reflexes.
The patient should have normal physiological parameters and not have any medication which could mimic brainstem death.

The diagnosis implies that there will be no recovery to normal brain function.

35

A 17-year-old male is returning from work as a painter and decorator. He is the passenger in a van, wearing a seatbelt. The van crashes and rolls over.
He is brought to the Emergency department where he is triple immobilised and on a spinal board, and is complaining of severe back pain. He cannot feel any sensation to pinprick or light touch below his nipples. He is unable to move his lower limbs.
At what level of the spinal cord is the lesion likely to have occurred?
(Please select 1 option)
T4
T5
T6
T7
T8

The sensory level is defined as the lowest dermatome which has normal sensory function.

The nipples correspond to the T4 dermatome level.

36

A 57-year-old woman who has previously consulted a neurosurgeon due to neck problems falls from the top of stairs.
She states that she landed directly on her face, with her neck being forced backwards.
On examination, the patient has loss of motor function of both the upper and lower limbs, but the upper limbs appear to be much more affected than the lower.
What is the name of this spinal cord syndrome?
(Please select 1 option)
Anterior cord syndrome
Brown-Sequard syndrome
Central cord syndrome
Posterior cord syndrome
Spinothalamic cord syndrome

Central cord syndrome classically occurs in a patient who already has cervical canal stenosis.

It is characterised by a greater loss of power in the upper (rather than the lower) limbs, with varying degrees of sensory loss.

Brown-Sequard syndrome is caused by hemi-section of the cord and results in ipsilateral motor loss and loss of position with contralateral pain and temperature loss.

37

Causes of hypercalcaemia
A Addison's disease
B Drug therapy
C Metastatic bone disease
D Myeloma
E Paget's disease
F Primary hyperparathyroidism
G Sarcoidosis
H Secretion of PTH related peptide
I Thyrotoxicosis
J Vitamin D excess
Which of the following diagnoses is likely to explain the presentation of a 54-year-old female found to have a serum calcium of 2.9 mmol/l?
Normal ranges are
Serum calcium 2.2-2.6 mmol/l
PTH 3.5-5.5 pmol/l
She presents with weight loss, cough and lethargy. She has a past history of hypertension for which she takes amlodipine and ramipril. She smokes 10 cigarettes daily and her chest x ray reveals a left hilar mass. Bone scan is normal. Her PTH concentration is 0.8 pmol/l.

She presents with tiredness. She has a past history of hypertension for which she takes bendroflumethiazide and ramipril. She smokes 10 cigarettes daily, her chest x ray is normal and she has a PTH concentration of 20.3 pmol/l.

She presents with tiredness, dyspnoea and erythematous tender nodules on the fronts of her shins. Her chest x ray reveals bilateral hilar enlargement. She smokes five cigarettes daily. Her PTH is 1 pmol/l.

The first case has a low parathyroid hormone (PTH), presents with weight loss, and has features suggesting lung cancer.

Squamous cell lung cancer, in particular, produces PTHrp, which is not detectable with conventional PTH assays and must be specifically requested. The absence of any metastatic deposits with bone scan argue against bony involvement.

The second case has primary hyperparathyroidism with elevated Ca and PTH.

Bendroflumethiazide causes hypercalcaemia but would result in appropriate suppression of PTH if this were the case.

The final case has erythema nodosum and bilateral hilar lymphadenopathy suggestive of sarcoidosis.

Hypercalcaemia associated with sarcoidosis is related to excess vitamin D synthesis by the granulomas but, as the most appropriate diagnosis is requested, one must select sarcoidosis.

38

Diagnosis of hypercalcaemia
A Addison's disease
B Drug therapy
C Familial benign hypocalciuric hypercalcaemia
D Myeloma
E Paget's disease
F Primary hyperparathyroidism
G Sarcoidosis
H Secretion of PTH related peptide
I Thyrotoxicosis
J Vitamin D excess
Which of the diagnoses is most likely to explain the following results found in a 53-year-old female who is admitted for hip replacement due to osteoarthritis? She is otherwise well.
Normal ranges:
Calcium 2.2-2.6 mmol/L
Phosphate 0.8-1.4 mmol/L
PTH 3.5-5.5 pmol/L
ESR 0-10 mm/hr
First results:
Calcium 2.85 mmol/L
Phosphate 0.8 mmol/L
PTH 4.2 pmol/L
ESR 20 mm/hr

Second results:
Calcium 3 mmol/L
Phosphate 0.8 mmol/L
PTH 8 pmol/L
ESR 12 mm/hr

Third results:
Calcium 2.8 mmol/L
Phosphate 2 mmol/L
PTH 0.9 pmol/L
ESR 25 mm/hr

The first and second cases are most likely to have hyperparathyroidism with elevated parathyroid hormone (PTH) in one and the inappropriately normal PTH in the face of hypercalcaemia. The negative feedback would usually result in a lowering of PTH in response to a raised serum calcium (from whatever cause)

The low phosphate is typical of hypocalcaemia.

The other potential, but less likely explanation for the first case is familial benign hypocalciuric hypercalcaemia (FBHH) due to a mutation of the calcium sensing receptor (CaSR) with loss of function. It is a rare condition. No treatment is needed for this condition: parathyroidectomy should avoided. It is autosomal dominant. Homozygous cases can present with severe neonatal hypercalcaemia.

The final case has elevated calcium and phosphate and low PTH suggesting that something other than PTH is responsible for the hypercalcaemia. As the patient is otherwise asymptomatic, the most likely cause is vitamin D excess, often taken for arthritic complaints. The give away is the elevated phosphate, which is typical of vitamin D excess.

39

Bronchial adenoma
B Carcinoid tumour
C Chondroma
D Large cell carcinoma
E Mesothelioma
F Pancoast's tumour
G Secondary lung tumour
H Small cell carcinoma
I Squamous cell carcinoma
Select the most appropriate option from the given list that would explain the following presentations.
A 62-year-old smoker presents with cough, haemoptysis and weight loss. His chest x rays reveal a central cavitation with multiple metastases outside the thoracic cavity.

A 54-year-old non-smoker presents with a rapidly worsening cough, haemoptysis, and dyspnoea. His bloods show altered blood biochemistry and increased calcium levels. x Ray reveals mediastinal gland enlargement.

A 74-year-old man with a prostate cancer presents with cough and weight loss. Chest x ray shows a cannonball appearance.

Squamous cell carcinoma accounts for the majority of lung cancers (>60%). These are common with smokers and tend to be centrally placed. They tend to cavitate and metastasise outside the thoracic cavity.

Adenocarcinoma, on the other hand, is common with elderly, non-smoking women. It tends to be sited at the periphery of the lung.

Small cell carcinoma may exist in the classical oat cell form or as an intermediate cell type. These tumours are highly malignant and are usually disseminated at presentation. These tumours are often associated with ectopic hormone production and paraneoplastic syndromes (ACTH secretion and ADH secretion but ectopic PTH secretion is usually due to squamous cell Ca). Less than 5% of such tumours are suitable for surgical management and they are best treated by chemotherapy.

The lungs are frequent sites of metastatic tumours. Although cannonball appearance in chest radiography may suggest a metastatic lesion, it is also seen with primary lung tumours. It has to be acknowledged that metastatic disease may assume a variety of radiographic appearances from a finely nodular disease to an infiltrative, poorly defined opacity.

40

Stridor
A Acute laryngitis
B Angioneurotic oedema
C Bacterial tracheitis
D Croup
E Diptheria
F Epiglottitis
G Foreign body inhalation
H Retropharyngeal abscess
I Smoke inhalation
J Vocal cord palsy
For each patient described below choose the single most likely option from the given list:
A 9-month-old boy is referred to ENT as he has been noted to have stridor. He sometimes chokes when drinking or feeding. His head circumference has risen from the 50% at birth to the 98% and he has short limbs.

A 4-year-old girl attends a birthday party and develops a choking episode. She recovers, but over the next two days becomes more unwell with a fever and a stridor. She is found to have marked intercostal recession.

A 3-year-old boy is brought to casualty with a sudden onset of stridor. Over the past three days he has been unwell with coryzal symptoms and ear temperature of 38.2°C.

The 9-month- old child has achondroplasia, which is often associated with hydrocephalus (Arnold-Chiari malformation). This in turn can be associated with vocal cord palsy.

Croup may be caused by different viruses although most commonly as a result of infection with parainfluenza. Typically it occurs in young children a few days after a coryzal illness with symptoms of a barking cough, a low grade fever and an inspiratory stridor. Symptoms are worse at night.

The 4-year-old girl developing fever and stridor following a birthday party is a classical history for inhalation of a foreign body, for example, a peanut. This results in deterioration over 24-36 hours and widespread respiratory signs.

41

Which of the following is untrue regarding type 1 respiratory failure?
(Please select 1 option)
Is associated with ventilation - perfusion mismatch
Is caused by adult respiratory distress syndrome
Is seen in pneumothorax
Occurs at high altitude
Oxygen therapy may cause an increased pCO2

Oxygen therapy may cause an increased pCO2

Type 1: Oxygenation failure with low O2 and low/normal pCO2 (for example, pulmonary embolism, asthma, PPH, left ventricular failure).

Type 2: Ventilatory failure - low O2 and high pCO2 (chronic obstructive airways disease, muscular weakness, for example, Guillain-Barré). In this patient group, chronic hypercapnia results in dependence on a hypoxic drive for ventilation. If this is lost with O2 therapy, then it can cause hypoventilation and huge rise in pCO2.

Pneumothorax results in reduced lung volume causing a type 1 respiratory failure if large enough and may cause a type 2 respiratory failure in tension.

42

Which of the following is true of hyperventilation?
(Please select 1 option)
Decreases pO2 of arterial blood
Increases concentration of ionic calcium
Lowers blood pH
Occurs with cerebral injury
Raises pCO2 of arterial blood

Hyperventilation is associated with a respiratory alkalosis and hence raised blood pH, lowered pCO2 and raised pO2.

Cerebral injury may precipitate hyperventilation.

The raised pH reduces ionised calcium concentrations and this is why tetany can occur in association with hyperventilation.

43

Which of the following is not a recognised feature of pulmonary embolism?
(Please select 1 option)
Collapse of the affected lung segments
Decreased left atrial pressure
Long PR interval on the electrocardiogram
Necrosis of lung tissue
Pulmonary hypertension

Long PR interval on the electrocardiogram

Decreased left atrial pressure - if massive.

Long PR interval on the electrocardiogram - a change in electrical axis characterised by an S wave in lead I and a Q wave and T wave inversion in lead III (S1Q3T3), sinus tachycardia, T wave inversion in leads V1 - V3, small QRS complexes.

Pulmonary hypertension and right heart failure may be the presenting features of multiple pulmonary emboli.

44

n an acute pulmonary embolism (PE), which of the following statements is correct?

D-dimer assay has high specificity
If associated with a pleural effusion, is characteristically haemorrhagic
If the embolus obstructs less than 10% of pulmonary circulation it is regarded as minor
If the x ray is normal, then one must question the diagnosis
The white cell count (WCC) is characteristically less than 10

If associated with a pleural effusion, is characteristically haemorrhagic

D-dimer assay has High sensitivity but low specificity (also positive in disseminated intravascular coagulation (DIC)/malignancy/after surgery).

Surprisingly enough, a PE is considered minor if it obstructs less than 50% of the pulmonary vasculature.

The x ray is often normal.

PE has characteristically increased WCC and erythrocyte sedimentation rate (ESR).

45

Which of the following is an uncommon feature of lung cancer?
(Please select 1 option)
Dyspnoea
Facial swelling
Horner's syndrome
Pericardial effusion
Raynaud's syndrome

Raynaud syndrome

Lung cancer causes dyspnoea, particularly in the advanced stages. Conversely, lung cancer may be an incidental feature in patients presenting with dyspnoea.

Lung cancer may be associated with facial swelling through superior vena cava (SVC) obstruction or ectopic Cushing's syndrome. Hoarseness, with involvement of the recurrent laryngeal nerve, may occur with tumour infiltration or lymph metastases.

Horner's syndrome is a well recognised consequence of an apical lung cancer (Pancoast's tumour) which is associated with symptoms related to involvement of the lower brachial plexus (C8,T1) with pain in the shoulder and upper inner arm.

Pericardial effusion occurs due to infiltration/metastases. Cardiac involvement in advanced malignancy/metastases is relatively common but often not symptomatic.

Secondary Raynaud's phenomenon due to a paraneoplastic phenomenon is rare.

46

The oxygen dissociation curve is shifted to the left by which of the following?
(Please select 1 option)
Increased 2,3-DPG
Increased haemoglobin concentration
Increased partial pressure of carbon dioxide
Reduced pH
Reduced temperature

Reduced temperature

The curved shape of the oxygen dissociation curve means that the loading of oxygen to the tissues is little affected by significant drops in alveoli PO2 concentration.

The steep lower part of the dissociation curve means that peripheral tissues can take off large amounts of oxygen for only a small drop in capillary PO2, assisting the diffusion of oxygen into the tissues.

The position of the oxygen dissociation curve is shifted to the right by acidosis, hypercapnia, raising the temperature, and increasing the amount of 2,3-DPG (23 diphosphoglycerate, an end product of red cell metabolism, the concentration of which increases in chronic hypoxia, either at altitude, or in chronic lung disease).

A reduced haemoglobin reduces the total oxygen carrying capacity of the blood, but does not change the shape of the curve.

47

Which of the following is not a feature of hypomagnesaemia?
(Please select 1 option)
Hypocalcaemia
Inhibition of PTH secretion
Muscle hypotonia
Respiratory paralysis
Ventricular arrhythmias

Hypomagnesaemia is associated with hypocalcaemia (due to reduced parathyroid hormone [PTH] secretion) and hypokalaemia.

It is associated with clinical features such as fits and arrhythmias.

Muscle hypotonia is associated with hypermagnesaemia.

48

Which of the following is not a cause of alkalosis?
(Please select 1 option)
Acute anxiety
Cardiogenic shock
Loop diuretic treatment
Primary hyperaldosteronism
Pyloric stenosis

Cardiogenic shock would be associated with a metabolic and respiratory acidosis.

Anxiety is associated with hyperventilation and a respiratory alkalosis.

Diuretics and primary hyperaldosteronism are also associated with metabolic alkalosis.

Pyloric stenosis is associated with vomiting and acid losses - metabolic alkalosis.

49

Hoarseness may be caused by which of the following?
(Please select 1 option)
Antibiotic therapy
Dystrophia myotonica
Glossopharyngeal nerve neuropraxia
Hodgkin's disease
Thyrotoxicosis

Hoarseness can occur as a consequence of

Infections (laryngitis - bacterial, viral or fungal)
Drugs (particularly steroids - hence the connection with RA)
Surgery (following injury to recurrent laryngeal nerve after thyroidectomy)
Neurological diseases such as myasthenia gravis (not myotonica)
Laryngeal tumours.

50

A 69-year-old man presents to the emergency department with a four to five month history of cough and weight loss. He was diagnosed with prostate cancer six months earlier for which he is undergoing treatment.
Chest x ray reveals a cannonball appearance in the right lung and diffuse infiltrative opacity in the left lung.
Which one of the following is the most likely diagnosis in this patient?
(Please select 1 option)
Carcinoid tumour
Large cell undifferentiated carcinoma
Lung metastases
Mesothelioma
Pancoast tumour

The lungs are frequent sites for metastasis from tumours elsewhere in the body. Although cannonball appearance in chest radiography may strongly suggest a metastatic lesion, it may also be seen with primary lung tumours.

It has to be acknowledged that metastatic disease may assume a variety of radiographic appearances from nodular disease to an infiltrative, poorly defined opacity.

51

Which of the following is correct regarding pulmonary contusion in children?
(Please select 1 option)
Alveoli are filled with blood resulting in hypoxia
Artificial ventilation is always required
Is usually caused by penetrating injury
The chest x ray is always abnormal
There is always an associated rib fracture

Blood enters the alveoli because the pulmonary capillaries rupture, and hypoxia ensues. Administration of high flow oxygen is necessary.

Artificial ventilation on the paediatric intensive care unit is required in some cases.

Pulmonary contusion is usually the consequence of blunt thoracic trauma. It is relatively common due to the mobility of the chest wall.

52

Regarding cardiac tamponade in children, which of the following is correct?
(Please select 1 option)
Blood accumulates outside the pericardial sac
Blood volume available for ventricular filling during systole is reduced
Distended neck veins are always apparent
Emergency needle pericardiocentesis is contraindicated
This may occur following blunt trauma

Cardiac tamponade may follow blunt or penetrating injury.

Blood accumulates within the pericardial sac and during diastole less blood volume is available for ventricular filling, leading to reduced cardiac output and circulatory shock.

Distended neck veins may not be present if there is coexisting hypovolaemia.

Emergency pericardiocentesis is necessary followed by referral to cardiothoracic surgeons.

53

In chest trauma, urgent cardiothoracic surgical referral is unnecessary in which of the following?
(Please select 1 option)
Cardiac tamponade
Continuing haemorrhage following insertion of chest drain
Continuing massive air leak following insertion of chest drain
Disruption of the great vessels
Severe pulmonary contusion

The major reasons for referral are:

Continuing massive air leak or haemorrhage following insertion of chest drain
Cardiac tamponade, and
Disruption of the great vessels (this injury is usually rapidly fatal, unless the tear in the vessel has tamponaded itself).
Pulmonary contusion requires the administration of high flow oxygen and if severe, artificial ventilation, on the intensive care unit.

54

In massive haemothorax, which of the following is correct?
(Please select 1 option)
Air entry is absent
Blood accumulates in the extrapleural space
Blood may arise from chest wall vessels
The affected side is hyper-resonant to percussion
Thoracotomy is indicated if the chest drain output is greater than 500 ml in total

Blood accumulates in the pleural space and may arise from the lung parenchyma, pulmonary or chest wall vessels.

There is decreased air entry and dullness to percussion on the side affected.

A substantial proportion of the child's blood volume may be contained in the chest and may lead to circulatory shock. Intravenous volume replacement is necessary and insertion of a large bore chest drain.

The indication for thoracotomy in haemothorax is a chest drain output greater than 1000 ml in total, or an ongoing loss of greater than 100 ml per hour.

55

Which of the following statements is correct regarding thoracic outlet syndrome?
(Please select 1 option)
A cervical rib is present in 2% of the population
Has typically bilateral symptoms
Is due to compression, occlusion or damage of the subclavian vein in the neck
Is frequently due to apical lung tumours
Pain - shoulder, arm or hand - is the most common presentation

Pain - shoulder, arm or hand - is the most common presentation

Thoracic outlet syndrome (TOS) is caused by compression of the brachial plexus, subclavian artery or subclavian vein in the thoracic outlet.

Almost all patients (95%) present with neurological symptoms.

There are many non-anatomical causes - repetitive pressure: sports including weight lifting, archery, swimming and tennis; occupations involving repeated overhead work - plastering, painting, shelf stacking; obesity and poor posture.

Trauma, such as fractured clavicle, may cause TOS.

The commonest anatomical cause of arterial symptoms is a cervical rib, which occurs in 0.4% of the population. Although 70% of cervical ribs are bilateral, symptoms tend to be unilateral.

Neurological symptoms and signs include:

pain
paraesthesia
weakness
muscle wasting.
Vascular symptoms and signs include:

distended arm veins which do not collapse even on limb elevation
venous thrombosis
cyanosis
oedema
arterial thrombosis (acute ischaemia or claudication) and embolisation (digital ischaemia)
post-stenotic dilatation and aneurysm formation

56

With which of the following is hypercapnoea NOT associated?
(Please select 1 option)
Exhausted soda lime granules
Head injury
Metabolic alkalosis
Respiratory acidosis
Respiratory alkalosis

Respiratory alkalosis

Hypercapnoea is defined as an end tidal CO2 over 6 kPa (45 mmHg) and occurs in a respiratory acidosis (not alkalosis). This may be a primary respiratory acidosis, for example.:

head injury
central nervous system depression
spinal cord lesion, and
fatigue of respiratory muscles.
A respiratory acidosis may also occur as a compensatory mechanism secondary to a metabolic alkalosis.

Exhausted soda lime granules cause the inspired concentration of carbon dioxide to increase (rebreathing), and are a recognised cause of hypercapnoea.

Please note that hypercapnoea is an increased ET CO2, and hypercarbia is an increased arterial PCO2.

57

Which of the following statements concerning a patient with a dissecting thoracic aortic aneurysm is correct?
(Please select 1 option)
A dissecting aneurysm of the ascending thoracic aorta should initially be managed with induced hypotension
A dissecting aneurysm of the descending thoracic aorta requires immediate surgical repair
Dissecting thoracic aneurysms can be classified according to the DeBakey classification
Invasive arterial blood pressure monitoring should be placed in the left arm
Severe metabolic alkalosis may occur during aortic cross-clamping

DeBakey
Thoracic aortic dissections are classified according to either the DeBakey or the Stanford classifications. DeBakey has three types:

Type 1 involves the ascending and descending aorta
Type 2 is limited to the ascending aorta
Type 3 is limited to the descending aorta with a tear distal to the origin of the left subclavian artery.
Stanford type A incorporates the DeBakey types 1 and 2 and Stanford type B is similar to the DeBakey type 3.

Ascending aortic dissections require immediate surgical repair.

Descending aortic dissections should initially be managed by induced hypotension and beta adrenoreceptor blockade. Systemic arterial pressure measurement should be via a cannula inserted into the right radial artery, as the left subclavian artery may be involved in the dissection or clamped at surgery.

A severe metabolic acidosis (not alkalosis) may develop during aortic cross clamping, which may require bicarbonate administration.

58

Adult respiratory distress syndrome results in/from which of the following?
(Please select 1 option)
From disseminated cancer
From indirect lung injury
In a hyaline membrane
In increased lung compliance
In patchy consolidation on chest radiograph

Adult respiratory distress syndrome (ARDS) is an acute, diffuse, inflammatory process, resulting from direct or indirect pulmonary injury.

ARDS is most commonly seen in patients with sepsis, but can also occur after

Trauma
Burns
Inhalation injuries
Shock
Pancreatitis.
Indirect or direct lung injury initiates an abnormal behaviour and movement of neutrophils, platelets and macrophages. Neutrophils and platelets attach to capillary endothelium, causing capillary leakage. This leads to oedema of lung tissue and thickening of the alveolar-capillary membrane.

In addition, some of the fluid in the pulmonary parenchyma may leak into the alveoli, giving the characteristic appearance of a hyaline membrane.

Pulmonary fibrosis in the later stages of the disease leads to

A decrease in the functional residual capacity
Further decrease in lung compliance
An increase in the shunt effect.
Pulmonary signs are often minimal or non-specific, the patient simply being breathless, progressively tachypnoeic, hypoxic and then cyanotic.

Chest radiograph may be normal in the early stages but later shows bilateral diffuse pulmonary infiltration.

59

Pneumothorax in neonates and infants is most commonly associated with which of the following?
(Please select 1 option)
Neonatal meconium aspiration syndrome
Pertussis
Pneumococcal pneumonia
Staphylococcal pneumonia
The use of positive airways pressure in the treatment of respiratory distress syndrome

The use of positive airways pressure in the treatment of respiratory distress syndrome

Pneumothorax is most commonly associated with positive pressure ventilation for premature neonates with respiratory distress syndrome. It is also associated with meconium aspiration. Pneumothorax in infancy may occur as a consequence of staphylococcal pneumonia and can occur with pneumococcal pneumonia, pertussis (whooping cough) and TB. Trauma is a cause at all ages. In the developing world pyogenic lung infection (74%) and TB (21%) account for the majority of spontaneous pneumothoraces.

60

Which of the following statements is true regarding the carotid body chemoreceptors?
(Please select 1 option)
Have a blood flow of over 5 ml/100 g per minute
Inhibited by a decrease in pH of arterial blood
Responsible for production of reflex peripheral vasoconstriction
Stimulated by an increase in pO2 of arterial blood
Stimulated in a hypertensive subject at rest

The carotid sinus is a baroreceptor responding to hypotension and mediating vasoconstriction, while the carotid body is a chemoreceptor.

Respiratory arrest and circulatory shock dramatically increase chemoreceptor activity, leading to enhanced sympathetic outflow to the heart and vasculature via activation of the vasomotor centre.

The carotid body has the highest blood flow of any tissue (50 ml/100 g per minute).

61

Which of the following is correct in a patient with left sided tension pneumothorax?
(Please select 1 option)
An urgent chest x ray is mandatory
Neck veins are usually distended
Needle thoraco-centesis should not be performed if the second intercostal space in the mid-clavicular line cannot be accurately identified
The insertion of a chest drain is only indicated if there is an associated rib fracture
The trachea is pushed towards the left

Tension pneumothorax is a clinical diagnosis and a life-threatening emergency.

The chest is hyperexpanded, hyperresonant, neck veins are distended (due to obstruction of venous return to the superior vena cava), the trachea is pushed towards the opposite side, and breath sounds are reduced.

Though the second intercostal space in the mid-clavicular line is the preferred site, a needle (cannula) could be inserted through any intercostal space on the affected side, since it is essential to relieve the pressure as soon as possible.

This should be followed by formal chest drain insertion and connected to an underwater seal (in all patients) and forms an integral part of the resuscitation.

62

Which of the following is true of carcinoma of the bronchus?
(Please select 1 option)
Causes unilateral ptosis
Is more common in women
Is not associated with exposure to ionising radiation
May lead to Conn's syndrome
Small cell type is common in young adults

Carcinoma of the bronchus is more common in men than women.

Their incidence increases with

Advancing age
History of smoking
Exposure to radiation and
Industrial pollutants such as asbestos, iron oxide and chromium.
Small cell carcinoma occurs most commonly in the middle-aged and the elderly.

The complications are a result of the tumour impinging or eroding the surrounding vital structures:

Involvement of the recurrent laryngeal nerve palsy leading to hoarseness of voice
Compression of the oesophagus leading to dysphagia
Pressure on the superior vena cava leading to facial engorgement and
Horner's syndrome (Pancoast's tumour).
Cushing's syndrome may be seen in patients with small cell carcinomas due to ectopic production of adrenocorticotropic hormone (ACTH).

63

Which of the following is correct regarding median nerve injury at the level of the wrist?
(Please select 1 option)
Can result from carpal dislocation This is the correct answerThis is the correct answer
Causes sensory loss over the little finger
Is commonly seen in children
Leads to motor loss of all the thenar muscles
Leads to paralysis of the flexors of the wrist and fingers

Can result from carpal dislocation

Median nerve (C5 - T1) is commonly injured near the wrist in adults due to lacerations in front of the wrist or by carpal dislocation, although the nerve can be injured anywhere along the arm or the forearm from trauma.

In children, by contrast, the median nerve is commonly injured at the level of the elbow frequently due to supracondylar fractures of the humerus.

Median nerve injuries at the wrist cause sensory loss over the thumb, index, middle, and occasionally ring finger (lateral half); motor loss includes the thenar group of muscles except adductor pollicis (supplied by ulnar nerve) and the lateral two lumbricals.

There is paralysis of the flexors of the wrist and fingers (with the exception of flexor carpi ulnaris and the medial part of flexor digitorum profundus) and pronators of the forearm only if the injury is at the level of the elbow.

64

Which of the following is a recognised cause of finger clubbing?
(Please select 1 option)
Carcinoid tumour
Chronic pancreatitis
Ileo-caecal tuberculosis
Iron deficiency anaemia
Liver cirrhosis

Causes of clubbing may be categorised into

Respiratory (cystic fibrosis, mesothelioma, bronchiectasis, fibrosis, lung carcinoma)
Gastroenterological (lymphoma, inflammatory bowel disease, cirrhosis) and
Cardiac (cyanotic heart disease, myxoma, bacterial endocarditis).
Iron deficiency anaemia causes koilonychia.

65

The affinity of haemoglobin for oxygen is increased by which of the following?
(Please select 1 option)
Alkalosis
Elevated arterial pCO2
Elevated red cell 2,3 diphosphoglycerate concentrations
Pyrexia
Reduced haematocrit

The oxyhaemoglobin dissociation curve moves to the right (that is, reduces oxygen affinity) in presence of acidosis, pyrexia and increased red cell 2,3 diphosphoglycerate concentrations.

Anaemia and heart failure also improve unloading of oxygen.

66

Which of the following is correct regarding surgical resection of a squamous cell bronchogenic carcinoma in a 64-year-old man?
(Please select 1 option)
An FEV1 of 2 L is a major contraindication to surgical resection
In the presence of finger clubbing indicates that liver metastases are already present
Is precluded if a CT scan of the thorax shows enlarged mediastinal lymph nodes
Positive sputum cytology excludes the need for bronchoscopic examination of the airways
With associated hypercalcaemia makes further assessment for surgery unnecessary

Is precluded if a CT scan of the thorax shows enlarged mediastinal lymph nodes

Patients are clearly operable on the basis of spirometry if FEV1 is greater than 1.5 litres for lobectomy and greater than 2 litres for pneumonectomy. Those with worse spirometric function may need full pulmonary function including transfer factor, and exercise testing.

Finger clubbing is related to hypertrophic pulmonary osteoarthropathy (HPOA) which is a non-metastatic manifestation of malignancy.

Mediastinal lymphadenopathy is usually associated with a poor prognosis although there may be a role for surgery and adjuvant chemotherapy in those with metastases to ipsilateral mediastinal lymph nodes and subcarinal lymph nodes (N2).

Bronchoscopy is useful to identify involvement of carina or if tumour is within 2 cm of the carina which means the cancer is inoperable.

Hypercalcaemia may be associated with parathyroid hormone-related peptide production associated with squamous cell carcinoma (non-metastatic manifestation of malignancy).

67

In which of the following is spontaneous pneumothorax not seen?
(Please select 1 option)
Asthma
Cystic fibrosis
Mycoplasma pneumonia
Pulmonary infarction
Staphylococcus aureus pneumonia

Mycoplasma

Apical bullae may form and pneumothorax occurs in up to 15% of patients. The classic description of spontaneous pneumothorax is in a young, tall, thin man with no overt lung disease.

Staphylococcus infection may cause lung cavities and hence a risk of pneumothorax.

68

Which of the following is correct regarding Idiopathic angio-oedema?
(Please select 1 option)
A. Does not respond to oral antihistamines
B. Has a higher mortality than hereditary angio-oedema
C. Is less common than hereditary angio-oedema
D. Is often associated with urticaria
E. Requires treatment with intramuscular epinephrine for the majority of attacks

A. Treatment involves intramuscular adrenaline with antihistamines and steroids.

B. Hereditary angio-oedema has a high mortality of up to 30% if not treated adequately.

C. Angio-oedema is usually due to (atopic or non-atopic) allergy. Hereditary angio-oedema is rare.

D. Urticaria does not usually occur in this condition.

E. There is often a danger of airways obstruction which responds to adrenaline in cases of allergy.