5. ENT, Max Fax & Ophthalmology

Question 1

1. A 79- year- old man attends for preoperative assessment prior to bilateral cataract surgery under general anaesthetic.
   His past medical history includes NYHA grade 3 heart failure. He had an acute coronary
   event ten months prior for which a drug- eluting stent was placed.
   He remains on aspirin and ticagrelor. The best management of his thromboprophylaxis in the perioperative period is:

A. Stop both antiplatelet agents and proceed
B. Stop both antiplatelet agents and bridge with IV heparin and proceed
C. Stop both antiplatelet agents and give platelet transfusion immediately preoperatively
D. Stop ticagrelor but continue aspirin and proceed
E. Stop both antiplatelet agents and postpone operation for two months

Answer 1

1. D
   Dual antiplatelet therapy is recommended for 12 months following insertion of a drug- eluting stent.

During this period, any change to this regimen must balance the risk of bleeding from surgery, the
risk of stent occlusion, and the risk of postponing surgery. Stent thrombosis carries a mortality
of 45%.

The complex decision making has been simplified into an algorithm shown in Figure 5.1.
This allocates patients to a high or low risk of bleeding depending on the type of surgery and then again
on the urgency of surgery. In this case the patient is in a low risk situation and answer D is the best
answer.

Answer E would also be a reasonable option, accepting that the patient is left awaiting surgery for a
further 2 months

Question 2

2. You perform an awake fibreoptic intubation on a patient with a difficult airway using a spray as you go technique. The maximum described dose
   for topical administration of lidocaine is:
   A. 3 mg/ kg
   B. 4 mg/ kg
   C. 6 mg/ kg
   D. 7 mg/ kg
   E. 9 mg/ kg

Answer 2

2. E
   Lidocaine is the most widely used agent for topical anaesthesia of the airway using a spray as you
   go technique. It is available in a variety of strengths and in combination with vasoconstrictors
   such as adrenaline (epinephrine) and phenylephrine. The maximum described dose for topical
   administration is 9 mg/ kg although doses this high should not be necessary. High doses of local
   anaesthetics should be used with caution, particularly in patients with liver disease.

Question 3

3. You anaesthetize a patient with bowel cancer for elective laparoscopic bowel resection. During laryngoscopy an unanticipated grade 4 larynx
   is encountered. Mask ventilation and oxygenation are satisfactory. Intubation fails after a total of four attempts at laryngoscopy. The next most appropriate step is:
   A. Wake the patient, abandon the procedure
   B. Wake the patient, perform awake intubation
   C. Intubate via supraglottic airway device
   D. Scalpel cricothyroidotomy
   E. Maintain oxygenation with nasal high- flow oxygen

Answer 3

3. C
   The question describes an elective case where the patient can be assumed to be fasted.
   There is no significant history stated regarding reflux. The Difficult Airway Society (DAS) guidance states
   that the next step is to insert a supraglottic airway device and this can be used as a conduit for
   intubation. Use of a video laryngoscope should be included during the maximum of four attempts
   at laryngoscopy. Further attempts should be avoided due to risk of worsening airway trauma and
   oedema. Clearly there is an emphasis to maintain oxygenation at all times which is being delivered
   adequately in this case as described.

Question 4

4. You anaesthetize a 17- year- old female for mandibular advancement surgery. The best choice of opioid for cough/ gag suppression during
extubation is:
A. Alfentanil
B. Fentanyl
C. Oxycodone
D. Morphine
E. Remifentanil

Answer 4

4. E
   In certain groups of patients (e.g., neurosurgical, maxillofacial, plastics, and those with significant
   cardiac or cerebrovascular disease), coughing, gagging, or straining on the ET tube is highly
   undesirable. The cough suppressant effects of opioid drugs and their ability to attenuate the
   cardiovascular changes associated with extubation are well known.
   Infusion of the ultrashort- acting opioid remifentanil attenuates these undesirable responses and
   may be used to provide the beneficial combination of a tube- tolerant patient who is fully awake and
   obeys commands. It is the opioid of choice due to its highly titratable nature.

Question 5

5. You assess a 23- year- old woman requiring tonsillectomy. She has a history of well- controlled epilepsy and has been seizure free on carbamazepine for three years. Which opioid drug is best avoided in this
patient?
A. Morphine
B. Alfentanil
C. Fentanyl
D. Diamorphine
E. Oxycodone

Answer 5

5. B
   Opioid analgesics all possess some degree of proconvulsant activity and are used to enhance EEG
   activity during seizure focus localization in epilepsy surgery. However, most opioids have a long
   history of safe use in patients with epilepsy. An exception to this is alfentanil, a particularly potent
   enhancer of EEG activity, which should be avoided or used with caution.

Question 6

6. A patient presents for squint surgery. On examination he has one eye where his gaze is deviated laterally and downward. There is an associated unilateral dilated pupil and ptosis. What is the most likely cause?
A. Optic nerve palsy
B. Abducens nerve palsy
C. Oculomotor nerve palsy
D. Bell’s palsy
E. Trochlear nerve palsy

Answer 6

6. C
   The optic nerve (CN II) transmits visual information. A complete oculomotor nerve palsy will
   result in a characteristic down and out position in the affected eye because the superior oblique
   (trochlear nerve IV) and lateral rectus (abducens nerve VI) maintain muscle tone compared with all the other paralysed muscles supplied by the oculomotor nerve. In addition, the oculomotor nerve
   also supplies the upper eyelid muscle (levator palpebrae superioris) and the muscles responsible for
   pupil constriction (sphincter pupillae). Bell’s palsy is a peripheral nerve lesion which affects the facial
   nerve with an absence of eye signs. Bell’s palsy is a peripheral nerve lesion resulting in weakness
   to the whole half of the face without forehead sparing. A unilateral facial weakness with forehead
   sparing is usually from a central lesion such as a stroke.

Question 7

7. A 21- year- old woman with Down’s syndrome presents for elective dental extractions under general anaesthesia. Her lead social worker is present. You confirm the patient does not have capacity. Which is the best description of the consent process required?

A. The patient can give consent
B. The patient’s next of kin should be sought and asked to give consent on her behalf
C. The social worker present should give consent on her behalf
D. An Adults With Incapacity (AWI) form/ Consent 4 form should be completed
E. The anaesthetist and dentist can proceed without consent as acting within the patient’s
best interest

Answer 7

7. D
   The Mental Capacity Act 2005 (England and Wales) and the Adults With Incapacity (Scotland) Act
   2000 state that doctors should assume a patient has capacity to consent to treatment unless proven
   and documented otherwise. This patient has no such capacity and therefore cannot give informed
   consent.
   No adult can give or withhold consent on behalf of another adult.
   While it is ideal to involve her parents in preoperative discussions, this has little bearing on the legal,
   ethical, and professional aspects of the consent process.
   Dental treatment is not an emergency procedure therefore there is no scope for the doctor or
   dentist to proceed without consent ‘acting in the patient’s best interest’.
   An AWI form should be completed by the most senior doctor present

Question 8

8. You anaesthetize a 51- year- old lady for a mastoidectomy. She has well- controlled hypertension and is otherwise well. Her preoperative electrocardiogram (ECG) shows 72 bpm sinus rhythm with a QTc interval of 0.51 seconds.
   You intend to give her a prophylactic antiemetic.
   What would be the best choice for this patient?
   A. Dexamethasone
   B. Ondansetron
   C. Droperidol
   D. Aprepitant
   E. Metoclopramide

Answer 8

8. A
   The normal range is 0.35– 0.44 seconds. Prolonged QTC interval is associated with ventricular
   arrhythmias. Dexamethasone is a very effective agent for postoperative nausea and vomiting
   (PONV) prophylaxis with a relative risk reduction of 25% and does not prolong the QTc interval.
   Droperidol and ondansetron are associated with QTc interval prolongation and should be avoided
   in patients who exhibit QTc interval prolongation preoperatively. Metoclopramide is not particularly
   associated with QTc interval prolongation but is a second line choice for postoperative nausea
   prophylaxis, especially at the 0- mg dose.
   Aprepitant is a very effective PONV prophylactic agent and does not prolong the QTc interval. It
   is not a first line agent due to its high cost but is licensed for chemotherapy- induced nausea and
   vomiting.

Question 9

9. A 48- year- old lady had a total thyroidectomy 3 hours ago. On return to the ward she reports some difficulty breathing and has slowly developed a high- pitched inspiratory noise. On examination, her neck
   appears more swollen than before. She is haemodynamically stable. You
   have administered 00% oxygen and called for help. What is the next
   appropriate management?
   A. Heliox
   B. Intubate immediately
   C. Nebulized adrenaline (epinephrine)
   D. Remove skin clips
   E. Nebulized steroids

Answer 9

9. D
   This clinical scenario illustrates the postoperative complications of bleeding and haematoma in the
   neck, post thyroidectomy, causing stridor and external compression of the airway. The next step
   should be to remove the skin clips to try to release the pressure on the airway. The patient may well need intubation but this may be difficult and the anatomy distorted by the haematoma if it is
   not released and this should be performed first.
   Nebulized adrenaline (epinephrine) and steroid are more useful in the management of stridor
   secondary to airway oedema.
   Heliox may be useful in some cases of stridor but the immediate need here is the evacuation of a
   haematoma as indicated by neck swelling. Heliox is a mixture of oxygen and helium. It has a similar
   viscosity to air but a lower density therefore can increase flow and reduce the work of breathing. It
   has significant effect in the large airways where flow is turbulent and therefore proportional to gas
   density. Its main uses are for large airway obstruction, e.g. secondary to tumour or oedema, and
   medium airway obstruction, e.g. croup

Question 10

10. A 68- year- old man is having laser removal of vocal cord tumour. You use a laser endotracheal (ET) tube to secure his airway. What other measure would best minimize the risk of an airway fire?
    A. Use total intravenous anaesthesia (TIVA) to maintain anaesthesia
    B. Use a nitrous oxide and oxygen mixture
    C. Use the lowest inspired oxygen concentration possible
    D. Put wet swabs around other tissues in the airway
    E. Do not inflate the cuff of the ET tube

Answer 10

10. C
    The measures recommended to reduce the risk of airway fires are to use air and oxygen mixtures
    and use low inspired oxygen concentrations, preferably FiO2 <25% if possible. Wet swabs around
    the airway tissues can be useful to prevent burns if a fire occurs and the cuff of the ET tube can be
    filled with saline ± methylene blue to give warning if it has been perforated by the laser.

Question 11

11. A 37- year- old lady had a thyroidectomy for a large multinodular goitre under general anaesthesia with a cervical plexus block for postoperative analgesia. When you review her the next day she is complaining of perioral tingling and muscle twitching. Her ECG show a rate of 91 bpm, sinus rhythm with a prolonged QT interval. What is the most likely
diagnosis?
A. Hypercalcaemia
B. Hyperkalaemia
C. Hypomagnesaemia
D. Hypocalcaemia
E. Hypokalaemia

Answer 11

11. D
    Temporary hypocalcaemia requiring replacement occurs in up to 20% of patients post thyroidectomy. Peri- oral tingling, muscle twitching, and tetanic are symptoms of hypocalcaemia, which may progress to seizures or ventricular arrhythmias if untreated.

The other biochemical abnormalities are much less likely and would present differently

Question 12

12. A 74- year- old man presents for microlaryngoscopy for suspected tumour. He has a history of alcohol excess and chronic obstructive pulmonary disease (COPD). He reports changes to his voice and
    dysphagia. Which investigation is best for dynamic airway assessment?
    A. Magnetic resonance imaging of head and neck
    B. Computed tomography (CT) of head and neck
    C. Flexible nasendoscopy
    D. Chest X- ray
    E. Ultrasound of airway

Answer 12

12. C
    All of these tests can provide useful information but the gold standard for dynamic airway assessment is the flexible nasendoscopy. If a recent one cannot be found in the notes, or if symptoms have deteriorated, this can be repeated prior to anaesthesia.

Question 13

13. You have a 74- year- old man for diagnostic laryngoscopy on your ENT list.
    The surgeon has requested a tubeless field. What is the main advantage of a supraglottic airway approach over a subglottic airway approach be?
    A. End- tidal CO2 monitoring is possible
    B. Laser can be used safely
    C. Delivery of a more consistent FiO2
    D. There is superior access for surgeons
    E. There is a less rapid increase in airway pressures

Answer 13

13. D
    The main advantage of a supraglottic airway over a subglottic one is that it gives a completely
    tubeless field and superior surgical access. Supraglottic airway devices do not allow end tidal
    CO2 monitoring or delivery of a consistent FiO2. They also have a more rapid increase in airway
    pressures with subsequent risk of barotrauma.

Question 14

14. A 48- year- old lady requires a total thyroidectomy. She is being treated preoperatively with carbimazole and propranolol. What best describes the mechanism of action of propranolol in the treatment of
    thyrotoxicosis?
    A. Inhibition of thyroid hormone synthesis
    B. Reduces vascularity of thyroid gland
    C. Reduction in anxiety
    D. Inhibition of peripheral conversion of T4 to active T3
    E. Decreasing amount of thyroid hormone released from the thyroid gland

Answer 14

14. D
    It is important that the patient is euthyroid before surgery.
    Propanolol inhibits the peripheral conversion of T4 to T3 and controls the sympathetic effects of
    hyperthyroidism. Other antithyroid drugs include: carbimazole, which prevents thyroid hormone synthesis;
    propylthiouracil, which inhibits conversion of T4– T3; iodine (Lugol’s solution), which inhibits thyroid
    hormone production and reduces the vascularity of the thyroid gland.

Question 15

15. A patient is admitted to the intensive treatment unit after an uncomplicated neck dissection. His past medical history is otherwise unremarkable. He has a surgical tracheostomy. He has been haemodynamically stable for the past 8 hours since surgery, with oxygen
    saturation 98% on FiO2 0.35 with continuous positive airway pressure 5 cmH2O. You are asked to see him as he is gradually desaturating.
    Currently his SaO2 91% and he appears anxious and dyspnoeic. You call for help. What is the next most important step?
    A. Remove the tracheostomy tube and replace with one a size larger
    B. Deliver high- flow 100% oxygen to both face and tracheostomy
    C. Look, listen, and feel at the mouth and tracheostomy
    D. Prepare for oral intubation
    E. Attempt suction of the tracheostomy tube

Answer 15

15. C
    After calling for help, you must next look, listen, and feel for breathing at both the mouth and
    tracheostomy. This may be aided by waveform capnography if available, or use of a Mapleson C
    breathing system and reservoir bag. This ascertains the presence or absence of a patent airway at
    both sites and whether spontaneous breathing is present.
    When breathing is present, oxygen should be applied to both mouth and tracheostomy. If breathing
    is absent then a pulse check ± CPR is carried out.
    Attempting suction of the tracheostomy tube may potentially dislodge any obstructing clot
    or mucus further down the respiratory tract. Removing the tube from an acutely formed
    tracheostomy will lead to loss of the tract and potentially the whole airway.

Question 16

16. You anaesthetize a 17- year- old female for surgical extraction of UL8 and LL8 wisdom teeth. She has no significant medical history. The best
choice of airway management is:
A. Reinforced laryngeal mask
B. Oral ET tube
C. Nasal mask
D. Face mask
E. Nasal ET tube

Answer 16

6. B
The airway should be protected from blood and dental foreign bodies by a cuffed ET tube. A nasal
tube is best indicated to facilitate surgical access when the dental extractions are bilateral. However,
on this occasion both wisdom teeth are on the left side (upper left and lower left) so an oral ET
tube can be placed and manoeuvred to the opposite side. This prevents the risk of nasal trauma
from a nasal tube yet still facilitates unilateral surgical access.

Question 17

17. A 34- year- old woman presents with goitre requiring elective total thyroidectomy surgery. She has recently been started on inhaled salbutamol for asthma from her GP.

Past medical history includes gastritis for which she takes omeprazole.
She has been increasingly breathless overnight in bed. She reports difficulty swallowing. Her voice is normal. The most useful investigation preoperatively is:
A. Pulmonary function tests
B. Echocardiography
C. Flexible nasendoscopy
D. Upper gastrointestinal endoscopy
E. CT neck and chest

Answer 17

7. E
A large retrosternal goitre causing tracheal compression symptoms in the mediastinum when lying
flat should be excluded. The patient is at risk of tracheomalacia. Further enlargement may also
result in dysphagia and recurrent laryngeal nerve palsy. Chest X- ray may show tracheal impression
but CT scan is the gold standard and will give more detailed information. Severe heart failure and
adult- onset asthma are worth investigating after identifying an absence of thyroid compressive
causes. Pulmonary function tests are likely to show obstruction in both asthma and external
compression so may not narrow the differential diagnoses. There are no obvious features of severe
reflux and the patient is already on proton pump inhibitor therapy.

Question 18

18. A 6- year- old child had an elective tonsillectomy which was uncomplicated. The indication was for sleep disordered breathing.
    Intraoperative analgesia included 2 μg/ kg fentanyl, 15 mg/ kg paracetamol, and 1 mg/ kg diclofenac. In recovery they are distressed and indicate a sore throat. What is the most appropriate initial
    management?
    A. Morphine 0.1 mg/ kg intravenous bolus
    B. Codeine 1 mg/ kg orally
    C. Codeine phosphate  mg/ kg intramuscularly
    D. Entonox until they calm down
    E. Reassurance from recovery nursing staff

Answer 18

8. A
The history of sleep- disordered breathing implies obstructive sleep apnoea, an indication for
tonsillectomy. A 6- year- old child should be deemed able to reliably communicate and indicate
pain. Simple reassurance alone is therefore inadequate. Codeine is contraindicated due to
genetically determined variations in metabolism (different CYP 2D6 phenotypes including ultrarapid
metabolizers who are at risk of toxicity, and slow metabolizers in whom codeine has an inadequate
effect due to lack of metabolism to morphine, its active form). The child is sore and requires strong analgesia. The pain is likely to persist in the medium term so entonox is not optimal. A strong
opioid such as morphine is indicated and has a more predictable dose response. The dose is correct
being 0.– 0.2 mg/ kg IV.

Question 19

19. Regarding complications of regional anaesthesia for ophthalmic surgery.
The most common complication is:
A. Retrobulbar haemorrhage
B. Globe penetration
C. Optic nerve injury
D. Muscle palsy
E. Chemosis

Answer 19

9. E
Chemosis is a swollen conjunctiva which subsides with compression and the passage of time. All
the others are much rarer complications. There have been no large randomized studies to compare
risks of complications between methods of local anaesthesia. Selection of technique therefore
remains largely a matter of personal preference and expertise

Question 20

20. A 24- year- old man presents with penetrating eye injury requiring urgent surgery. Which anaesthetic induction agent will provide the greatest fall
in intraocular pressure?
A. Midazolam
B. Etomidate
C. Ketamine
D. Propofol
E. Thiopental

Answer 20

20. D
    All IV induction agents lower IOP except ketamine.

Thiopental, propofol, and etomidate all cause
a fall in IOP. The fall is greatest with propofol, but at the cost of a greater reduction in arterial pressure. Induction agents which cause myoclonus, such as etomidate, should not be given in perforating eye injuries. Midazolam has no effect on IOP.

Question 21

21. A 26- year- old woman presents with a five- day history of dental pain due to abscess which the surgeons plan to drain under general anaesthetic.
    On examination she has mouth opening limited to two finger breadths.
    Previous anaesthetics as a child were uneventful. She is fasted for more than 6 hours. The best way to anaesthetize this patient is:
    A. Gas induction
    B. IV induction
    C. Rapid sequence induction
    D. Awake fibreoptic intubation
    E. Ask surgeons to operate under local anaesthetic dental block

Answer 21

2. D
The airway is made difficult by the reduced mouth opening. The only method which avoids this
problem is awake fibreoptic nasal intubation. After five days this restriction is unlikely to improve preinduction
with analgesia and will perhaps improve only slightly after a gas induction. Access via the
mouth will remain problematic. This together with the abscess will preclude effective local anaesthetic

Question 22

22. A 22- year- old man has sustained a penetrating eye injury as a result of assault. He has been drinking alcohol but is not intoxicated. His Glasgow Coma Scale (GCS) is 15. He has undergone a CT of head which excludes any significant head injury.
    The ophthalmologist is concerned that any
    significant delay could jeopardize the sight in this gentleman’s eye.
    What is the most appropriate management plan?
    A. Perform gas induction with oxygen/ nitrous oxide/ sevoflurane
    B. Rapid sequence induction (RSI) using thiopentone and suxamethonium  mg/ kg
    C. Perform an awake fibreoptic intubation
    D. Delay until no longer under the influence of alcohol
    E. Modified RSI with propofol and alfentanil 20 μg/ kg

Answer 22

22. B
    D is inappropriate given not clinically intoxicated and negative CT head.
    A is inappropriate due to potentially full stomach and increase in intra- ocular pressure due to nitrous oxide.
    C is inappropriate due to interaction of alcohol and sedative drugs. Without sedation hypertension
    is likely which may cause an increase in IOP.
    E is still a full stomach scenario therefore a muscle relaxant for optimal intubating conditions should
    be used.

Question 23

23. You have a patient on your list for parotidectomy. He is 56 years old and American Society of Anaesthesiologists score (ASA) 1. The
    surgeon informs you she will be using a facial nerve stimulator. The best technique to facilitate this is:
    A. Laryngeal mask airway (LMA), spontaneous ventilation
    B. LMA, intermittent positive pressure ventilation (IPPV), without muscle relaxant
    C. Endotracheal tube, IPPV using muscle relaxant at induction only
    D. Endotracheal tube, IPPV without muscle relaxant
    E. ETT, IPPV using suxamethonium at induction only

Answer 23

23. D
    The surgeon’s use of a facial nerve stimulator requires the neuromuscular junction to be intact and
    functioning normally. Non- depolarizing muscle relaxants should be avoided as these will lead to
    false negatives on facial nerve testing. Suxamethonium could be used at induction but this assumes
    the patient is of normal phenotype to ensure the block is not unduly prolonged. An LMA technique
    is not recommended for this operation as the surgeon requires to move the head, and venous
    pressure and pCO2 must be controlled.
    Remifentanil can be used from induction through maintenance to ensure balanced anaesthesia deep
    enough to permit ventilation without excessive volatile agent concentrations or muscle relaxant.

Question 24

24. A 79- year- old female patient with glaucoma presents for cataract surgery under local anaesthesia. The best local anaesthetic to use is:
    A. Pilocarpine %
    B. 2- Chloroprocaine 2%
    C. Lidocaine 2% with  in 200,000 adrenaline (epinephrine)
    D. Lidoocaine 2% plain
    E. Levo- bupivicaine 0.5%

Answer 24

24. D
    Lidocaine 2% plain is a safe, short acting amide local anaesthetic with fast onset making it ideal for
    cataract surgery. There is little post operative pain so longer acting drugs such as levo- bupivicaine
    have no additional benefit.
    Adrenaline (epinephrine) is a sympathomimetic and has a vasoconstricting effect. Adrenaline
    (epinephrine) containing solutions often contain preservative sodium metabisulphite also, which
    is potentially toxic to the globe. Adrenaline (epinephrine) can be absorbed systemically producing
    tachycardia, arrhythmias, and hypertension. As such, these solutions are avoided.
    Pilocarpine is a parasympathomimetic agent used when miosis is required and has no local
    anaesthetic activity.
    2- Chloroprocaine is a newer ester type local anaesthetic most commonly used in the USA at
    present.

Question 25

25. You undertake a project examining the time taken in seconds for 30 anaesthetists to perform a fibreoptic intubation on a mannequin. The
    same anaesthetists then undergo a teaching programme and are timed again. The recorded times indicate an equal mean, mode, and median.
    The best statistical test to compare the data is:
    A. t- test
    B. Paired t- test
    C. ANOVA
    D. Paired ANOVA
    E. Wilcoxon signed rank

Answer 25

25. B
    The data collected are quantitative not qualitative. The equal mean, mode, and median indicate
    a normal distribution. There are two groups made up of the same sample repeated, therefore a
    paired t- test is most appropriate to examine for significant difference between the groups. ANOVA
    is more appropriate for more than two normally distributed groups. Wilcoxon is more appropriate
    for non- normally distributed (skewed) data.