CRQ Paper 3

Question 1

Question 1. Russell, a 32-year-old man, has fallen from his mountain bike at speed. He landed on his head but was wearing a cycle helmet. You are part of the receiving trauma team in the Emergency Department. a) Russell tells you he cannot move his arms or legs. You proceed to examine Russell, starting with his upper limbs. Complete the table of upper limb myotomes. (4 marks)

Answer 1

1. Shoulder abduction = C5
   **Mnemonic: ‘C5/6 – pick up sticks
   ** C7/8 keep it straight’
2. Elbow flexion = C6
   **
3. Elbow extension = C7
4. Finger abduction = T1

Question 2

b) The patient’s observations are as follows: heart rate 40 beats/min, blood pressure
80/38 mmHg. (Spinal cord injury)
Explain these two findings. (2 marks)

Answer 2

○ Hypotension due to decreased
systemic vascular resistance
** Due to interruption of sympathetic neurons
○ Bradycardia as a result of unopposed vagal tone
** Due to interruption of sympathetic
cardioacceleratory neurons

Question 3

Based on the neurological examination, the patient is thought to have a cervical spinal
cord injury. List four indications for intubation in this clinical situation. (4 marks)

Answer 3

• Rapid shallow breathing
• High cervical cord injury
• Vital capacity < 15 mL/kg; serial vital capacity measurement worsening trend
• Hypercapnoea/PaCO2 > 6.0 kPa
• Poor cough
• Patient fatigue
** Respiratory failure is very common in cervical spinal cord injury. It is always better to perform a semi-elective as opposed to emergent intubation, as the
latter is more likely to lead to neurological injury through neck manipulation or hypoxaemia.

Question 4

List two precautions you would take when intubating this patient. (2 marks)

Answer 4

• Manual in-line stabilisation
• Rapid sequence induction Gastric emptying is reduced
in high spinal cord injury.

**Not acceptable: avoidance of
suxamethonium, as extra-junctional
acetylcholine receptors do not
develop for 48 hours.

Question 5

(ASCI)
The patient is now intubated and sedated, and you transfer the patient to the critical care unit. List eight aspects of acute critical care management that you would instigate.
(8 marks)

Answer 5

• Lung-protective ventilation/
6–8 mL/kg tidal volume

• Chest physiotherapy
• Tracheostomy Improved patient comfort,
allows cessation of
sedation.
• Vasopressors
**The mean arterial blood pressure target in spinal cord injury remains controversial.
• Catheterisation Prevents bladder
overdistension, which may precipitate reflex
bradycardia.
• Maintenance of spinal alignment/ log rolling
Thought to prevent
secondary cord injury.
• Spinal surgical referral/early surgical fixation
,Early surgical fixation aids mobilisation, reducing the
risk of developing pressure sores.
• Thromboprophylaxis
• Gut protection (prophylactic H2-
receptor antagonist or proton pump inhibitor)
**Unopposed vagal activity increases gastric acid secretion and peptic ulceration.
• Glycaemic control
**The stress response to trauma results in
hyperglycaemia.
• Bowel care/laxatives **Unopposed vagal input may result in paralytic ileus.
• Enteral nutrition
• Prevent pressure sores, e.g. pressure-relieving mattress, early
surgical fixation
• Normothermia
• Full secondary survey

Question 6

Question 2.
Insiya is a 74-year-old woman who is listed for an emergency laparotomy due to a
perforated diverticulum. She has a background history of ischaemic heart disease and is
currently on the waiting list for coronary artery bypass grafting. The operation is taking
place in a hospital with tertiary cardiac services.
a) Apart from a history of coronary artery disease, which five other features make up Lee’s
Revised Cardiac Index? (5 marks)

Answer 6

• History of congestive cardiac failure
• History of cerebrovascular disease
• Diabetes mellitus requiring insulin
• High-risk surgical procedure
• Creatinine >176 μmol/L

Lee’s Revised Risk Score of
0 = 0.4% risk of major intra-operative cardiac event,
score 1 = 0.9% risk,
score 2 = 6.6% risk,
score≥ 3 = 11% risk.

Question 7

Based on the history provided above, what is Insiyas percentage risk of perioperative cardiac
complications? (1 mark)

Answer 7

○ 6.6% (accept 6–7%)
○ Insiya scores two: one for ‘ischaemic heart disease’ and one for ‘high-risk
surgery

Question 8

The essential requirement for general anaesthesia in ischaemic heart disease is balancing
myocardial oxygen supply with myocardial oxygen demand. In the table below, give
three factors affecting myocardial oxygen supply and three factors affecting myocardial
oxygen demand. (6 marks

Answer 8

Oxygen supply: Any 3
• Diastolic time (not acceptable:
heart rate)
• Coronary perfusion pressure
(accept diastolic blood pressure)
• Arterial oxygen content
• Haemoglobin concentration
• Coronary artery diameter
Oxygen demand: Any 3
• Heart rate
• Ventricular wall tension
• Afterload (accept systemic
vascular resistance)
• Contractility

Question 9

Intra-operatively, Insiya develops ST depression on the five lead ECG. You immediately
inform the surgeon. Despite ensuring that there is adequate oxygenation and correcting
haemodynamic disturbance, the ECG changes persist. Insiya has a central line in situ and
you decide to commence glyceryl trinitrate (GTN).
d) What is the specific pharmacodynamic rationale behind the use of GTN in ischaemic
heart disease, and at what dose (μg/min) would you run the infusion? (2 marks)

Answer 9

Pharmacodynamic rationale:
°By reducing wall tension, GTN reduces myocardial oxygen demand and increases sub-endocardial O2 supply through
increased coronary
blood flow.
°Reduces left ventricular end-diastolic pressure (accept reduced
wall tension)
Dose: 10–200 μg/min

Question 10

(Perioperative MI)
Insiya’s lactate continues to increase and her urine output is decreasing. She is hypo-
tensive despite adequate filling. What is the likely diagnosis? (1 mark)

Answer 10

Cardiogenic shock (accept cardiac/
left ventricular failure)

Question 11

(Perioperative MI)
Following discussion with your supervising consultant, you decide to commence enox-
imone. State the drug class and its mechanism of action. (2 marks)

Answer 11

Drug class: Milrinone and enoximone are other examples of the so-called inodilators.
Specific phospho-diesterase III inhibitor
○Mechanism of action: Prevents degradation of cyclic adenosine monophosphate (accept increases intracellular cAMP, accept increases intracellular calcium movement)

Question 12

(Perioperative MI, cardiogenic shock)
What non-pharmacological treatment options could be considered? (3 marks)

Answer 12

• Intra-aortic balloon pump
**In a non-cardiac centre, these options may not be readily available!
• Urgent revascularisation
• Left ventricular assist device

Question 13

Question 3.
Lauren is a 22-year-old woman who has been sedated and ventilated on the Intensive Care
Unit for 4 days following a major trauma. She has been sedated with high-dose propofol and
alfentanil. The nurses are concerned that she is showing signs of propofol-related infusion
syndrome (PRIS).
a) List seven clinical manifestations of PRIS. (7 marks)

Answer 13

• Refractory bradycardia leading to asystole
** PRIS was originally described by Bray in the paediatric population in 1998 and has subsequently been reported in adult patients.
• Other cardiac arrhythmia, e.g. supraventricular tachycardia
• Metabolic acidaemia
**Base deficit greater than (more negative than) –10 mmol/L, due to lactate acidosis.
• Rhabdomyolysis
**Due to myocyte necrosis → myoglobinuria/ acute renal failure.
• Hyperkalaemia (plasma K+ > 5.5 mmol/L)
• Lipaemic plasma
**Due to hypertriglyceridaemia.
• Enlarged/fatty liver
• Progressive myocardial collapse/ cardiac failure

Question 14

b) What is the maximum dose of propofol (mg/kg/h) that should be used as an infusion?
(1 mark

Answer 14

4 mg/kg/h
** Whilst the quoted ‘safe’ dose is 4 mg/kg/h, fatal cases of PRIS have been reported after infusion doses as low as 1.9 mg/kg/h.
Genetic factors may play a role in the susceptibility of a
patient to PRIS.

Question 15

In addition to a high-dose propofol infusion, list four risk factors for developing PRIS.
(4 marks)

Answer 15

• Severe head injuries
• Sepsis
• Pancreatitis
• High endogenous or exogenous catecholamine or glucocorticoid levels
• Low carbohydrate supply leading
to increased lipolysis during times of starvation, e.g. burns or trauma
• Inborn errors of fatty acidoxidation
• Paediatric population

Question 16

What specific laboratory findings might be expected in a case of PRIS? (3 marks)

Answer 16

• Acidaemia (pH < 7.35)
• Raised lactate (>2 mmol/L)
• Elevated creatine kinase, with no
other obvious cause
• Myoglobinuria
• Hyperkalaemia (>5.5 mmol/L)
• Hypertriglyceridaemia
(>1.9 mmol/L)
• Raised serum creatinine

Question 17

(PRIS)
List four aspects of your clinical management of this case. (4 marks)

Answer 17

• Cessation of propofol infusion, use of alternative sedation
• Inotropic or vasopress or support
• Cardiac pacing for refractory bradycardia
• Haemodialysis to resolve acidaemia/renal failure
• Adequate carbohydrate
administration to suppress lipolysis, minimising lipid load
(e.g. avoiding TPN)
• Extracorporeal membrane oxygenation (ECMO) has been
used for combined respiratory and
cardiovascular support
** There is no specific
treatment for PRIS, just
supportive measures to
counteract its consequences.

Question 18

What is the mortality from PRIS? (1 mark)

Answer 18

Literature estimates range from 4%
to 18%

Question 19

Question 4.
A 5-year-old boy, Sebastian, is listed for a bilateral myringotomy and grommet insertion
under general anaesthesia. He has Down’s syndrome.
a) State the most common genetic abnormality causing Down’s syndrome. (1 mark)

Answer 19

Trisomy 21: the presence of a third
copy of chromosome 21 95% of patients with
Down’s syndrome have this genetic abnormality. The remainder have a
chromosomal translocation(4%) or mosaic trisomy
21 (1%).

Question 20

List six features of this child’s physical appearance that are characteristic of Down’s
syndrome. (6 marks)

Answer 20

• Brachycephaly
• Flat occiput
• Flat nasal bridge
• Brushfield spots in iris
• Epicanthic folds
• Upwardly slanting palpebral fissures
• Small mouth
• Macroglossia
• Small ears
• Single transverse palmar (Simian)
crease
• Obesity
• Short stature
• Short neck
• ‘Sandal gap’ between first and second toes

Question 21

Sebastian is known to have had surgery during the first year of life. List four congenital
abnormalities associated with Down’s syndrome which may have led to surgery.
(4 marks)

Answer 21

• Congenital heart disease (CHD):
atrial, atrioventricular and ventricular septal defects, patent ductus arteriosus, tetralogy of Fallot (accept up to two CHD
answers)
**Around 50% of babies born with Down’s syndrome have a congenital cardiac defect.
Mitral valve prolapse is a common finding in adults with Down’s syndrome.
• Subglottic stenosis Found in up to 8% of
patients.
• Duodenal atresia
**Eight percent of Down’s infants have duodenal atresia.
• Hirschsprung’s disease
• Pyloric stenosis
• Meckel’s diverticulum
• Imperforate anus

Question 22

Which haematological malignancy are children with Down’s syndrome particularly
susceptible to? (1 mark

Answer 22

Acute myeloid leukaemia (AML) 1 AML is 500 times more common in Down’s
syndrome, whilst acute lymphoblastic leukaemia is 20 times more common. It is
thought that leukaemogenic genes may be located on chromosome 21.

Question 23

On examination, Sebastian is thought to have a difficult airway. List four features
specific to Down’s syndrome which may make airway management more difficult.
(4 marks)

Answer 23

○ Atlantoaxial instability (AAI)
** Asymptomatic AAI is found in between 10% and 20% of Down’s syndrome children.
Two percent of children
have symptomatic AAI.
○ Cervical spondylosis ** Increasing incidence with age: ~70% by age 40

Question 24

Question 5.
You are called urgently to the delivery suite to assist in the management of Cindy, a 31-year-
old woman who has collapsed during the second stage of labour. You are told that the
working diagnosis is amniotic fluid embolism (AFE).
a) List three further obstetric and non-obstetric causes of maternal collapse in labour.

Answer 24

Obstetric:
** When faced with maternal collapse, ensure all potential causes are considered. AFE is a diagnosis of exclusion.
• Eclampsia
• Uterine rupture
• Placental abruption
• Peripartum cardiomyopathy
• Uterine inversion

Non-obstetric causes:
• Sepsis
• Pulmonary embolism
• Air/fat embolism
• Pulmonary oedema
• Heart failure
• Myocardial infarction
• Anaphylaxis
• High spinal
• Local anaesthetic toxicity
• Intracranial haemorrhage
• Drug reaction

The reported incidence of AFE ranges from 1:8000 to 1:80,000, and it accounts for 4.7% of direct maternal deaths in the UK. AFE occurs most commonly
during labour, but can occur during Caesarean section and following delivery.
Neonatal mortality is high (70%) and neurological injury is common in survivors.

Question 25

In the absence of any other clear cause for the collapse, list five clinical features that may aid the diagnosis of AFE according to the United Kingdom Obstetric Surveillance System (UKOSS) criteria. (5 marks)

Answer 25

• Foetal compromise • Cardiac arrest • Cardiac rhythm abnormalities • Hypotension • Coagulopathy • Haemorrhage • Seizure • Dyspnoea/cyanosis Any 5 The UKOSS criteria are based on acute maternal collapse with one or more of the stated features, in the absence of a more likely diagnosis.

Question 26

c) State the two main theories hypothesised in the mechanism of AFE. (2 marks)

Answer 26

1. Mechanical/embolic 2. Immunological Both theories hypothesise exposure of the maternal circulation to amniotic fluid or foetal antigens.

Question 27

A biphasic response to AFE is commonly described. What are the two key features of the phase 2 response? (2 marks)

Answer 27

Left ventricular failure/pulmonary oedema 1. Phase 1 (lasts up to 30min): pulmonary artery vasospasm, pulmonary hypertension, right ventricular failure, hypoxaemia and hypotension. 2. Phase 2: left ventricular failure and pulmonary oedema, DIC.

Question 28

On your arrival, you note that Cindy is unresponsive with no signs of life. List the key points of the immediate management of this patient. (5 marks)

Answer 28

• Call for help • Left lateral tilt or manual displacement • Airway management • Cardiopulmonary resuscitation **Management in AFE is supportive. Multi- disciplinary management and early senior help is key. • Deliver baby **Think about delivery of the baby early. • Expect and plan for massive haemorrhage in maternal survivors. Complete UKOSS AFE register

Question 29

Question 6. You are asked to review Sally, a 42-year-old woman, in pain clinic. She has a history of intractable low back pain. a) Complete the labels (i–vi) on the following figure. (3 marks)

Answer 29

i = Vertebral body ii = Pedicle iii = Lamina iv = Spinous process v = Superior articular process (accept facet joint) vi = Central spinal canal

Question 30

List five features in the history and five clinical signs that would suggest serious spinal pathology. (10 marks)

Answer 30

History Any 5 • Age of onset < 16 or > 50 years old • History of significant trauma • Thoracic pain • Bladder or bowel dysfunction • Constitutional symptoms: unexplained weight loss, fever, night sweats • Nocturnal back pain • Previous history of malignancy • Immunosuppression (e.g. long-standing steroid use, HIV infection) • Intravenous drug abuse • Presence of other medical illnesses/recent significant infection • Gait disturbance Clinical signs • Perianal/perineal sensory loss (saddle anaesthesia) or paraesthesias • Reduced anal tone • Hip or knee weakness • Point tenderness over the vertebral body • Severe or progressive neurological deficit in legs • Pyrexia

Question 31

The patient does not have any features of serious spinal pathology, nor does she have lower limb neuropathy. Give three aetiological origins of mechanical back pain. (3 marks)

Answer 31

○ Discogenic pain **Accounts for 40% of mechanical back pain, difficult to distinguish from other causes of lower back pain. ○ Sacroiliac joint pain **Accounts for 20% of mechanical back pain. Pain arising from this joint israrely present above the transverse process of L5. Stressing the joint may reproduce the patient’s pain. ○ Lumbar facet joint pain ** Accounts for 10%–15% of mechanical back pain in young patients, up to 40% in elderly. Characterised by pain that is worsened by rotation and extension, radiation into the leg, tenderness over the joints and paravertebral muscle spasm.

Question 32

(Chrinic back pain) During the consultation, you recognise that psychosocial factors are making a significant contribution to the patient’s pain behaviours. d) List four psychosocial factors that have been shown to indicate long-term chronicity and disability. (4 marks)

Answer 32

• A belief that back pain is harmful or potentially severely disabling • Fear avoidance behaviour and reduced activity levels • An expectation that passive, rather than active, treatment will be beneficial • A tendency to depression, low morale, and social withdrawal • Social or financial problems Any 4 These psychosocial factors are often referred to as ‘yellow flags’, whilst the symptoms and signs of serious spinal pathology are commonly called ‘red flags’.

Question 33

Question 7. Sophie, a 23-year-old woman, has a ‘crash Caesarean section’ for cord prolapse. You perform an uneventful general anaesthetic. Three hours later, you are asked to review Sophie, as she says she ‘was not asleep’. a) State and define the two classes of accidental awareness under general anaesthesia (AAGA). (4 marks)

Answer 33

○ Explicit awareness: conscious recollection of events, either spontaneously or as a result of direct questioning • Intra-operative explicit awareness may be with or without pain. ○ Implicit awareness: implicit memories exist without conscious recall, but they can alter behaviour after the event

Question 34

List six factors associated with an increased likelihood of AAGA. (6 marks)

Answer 34

• Neuromuscular blockade • Caesarean section • Thiopentone use • Rapid sequence induction • Total intravenous anaesthesia • Female patients • Early middle-age patients • Out-of-hours operating • Junior anaesthetists • Previous episode of AAGA Any 6 Not acceptable: induction and emergence – these are the most common phases of anaesthesia to experience awareness, but are not risk factors. These were the factors highlighted in the Royal College of Anaesthetists Fifth National Audit Project as being ‘over-represented’. Caesarean section carries the highest risk, at 1:670.

Question 35

How will you manage this clinical situation? (3 marks) awareness

Answer 35

• Involve consultant anaesthetist • See the patient accompanied by a nurse/midwife • Establish the exact nature of the wareness, i.e. explicit vs implicit, pain sensation experienced? • Always believe the patient and empathise • Explain the nature of the anaesthetic and how the awareness could have occurred • Invite questions from the patient, and offer follow-up – return at a later date, counselling, follow-up obstetric anaesthetic clinic ** It is important to establish whether this is truly a case of AAGA, or whether this was awareness of awake extubation. AAGA may cause significant psychological harm, such as anxiety/fear of future surgery and anaesthesia, sleep disturbances and flashbacks, nightmares and post-traumatic stress disorder.

Question 36

List four methods that can be used to monitor depth of anaesthesia. (4 marks)

Answer 36

• Clinical signs/observations • Isolated forearm technique • Lower oesophageal contractility • End-tidal volatile concentration • Frontalis electromyogram (EMG) • Electroencephalogram (EEG)-based (maximum 2 marks): pure EEG, Bispectral index (BIS), Narcotrend, M-Entropy. • Evoked potentials: auditory, motor, sensory

Question 37

e) Regarding the depth of anaesthesia, state electroencephalogram (EEG) wave patterns consistent with wakefulness, surgical anaesthesia and excessive anaesthesia. (3 marks)

Answer 37

○ Wakefulness: fine wave/β-wave activity ** Processed EEG, for example BIS, analyse the raw EEG for these wave patterns, and display a number between 0 and 100 corresponding to the depth of anaesthesia. Between 40 and 60 is considered a surgical plane of anaesthesia. ○ Surgical anaesthesia: spindle waves/ α-waves, θ (theta)/δ (delta) waves ○ Excessive anaesthesia: burst suppression

Question 38

Question 8. On a recent visit to his general practitioner, Glyn, a 58-year-old man, was noted to have unilateral tonsillar hypertrophy. He has been listed for a panendoscopy and biopsy. Your supervising consultant anaesthetist plans to use high-flow nasal oxygen therapy (HFNOT) to facilitate ‘tubeless surgery’. a) List four risk factors for developing oropharyngeal cancer. (4 marks)

Answer 38

• Tobacco: smoked or chewed **Tobacco use is the single greatest risk factor in the development of oropharyngeal cancer. • Alcohol • Human papillomavirus (HPV) infection • Male sex • Age > 55 years • Poor oral hygiene **The number of oropharyngeal cancers linked to HPV has increased dramatically the cause is unclear.

Question 39

b) Other than HFNOT, list two strategies to maintain oxygenation during an upper airway panendoscopy. (2 marks)

Answer 39

• Microlaryngoscopy tube and intermittent positive pressure ventilation • Supraglottic jet ventilation • Subglottic jet ventilation • Trans-tracheal jet ventilation

Question 40

c) How will you maintain anaesthesia during this case? (1 mark)

Answer 40

○ Total intravenous anaesthesia *It is not possible to deliver volatile anaesthetic agents using HFNOT.

Question 41

Regarding gas delivery, list two differences between HFNOT and conventional nasal cannulae. (2 marks)

Answer 41

HFNOT delivers: • Warmed (33°–43°C) • Humidified gas (95%–100% humidity) • At greater flow rate up to 60 L/min (must state flow rate for the mark) Traditional nasal cannulae deliver cold, dry oxygen. Patient discomfort generally limits the flow rate to ≤ 4 L/min.

Question 42

State two other perioperative uses of HFNOT. (2 marks)

Answer 42

• Intubation and difficult airway • Maintenance of oxygenation at extubation • Post-operative hypoxaemia • Procedural oxygenation: dental procedures, awake fibre-optic intubation, bronchoscopy (Not acceptable: critical care applications) Any 2 HFNOT significantly extends the apnoeic period.

Question 43

List five physiological benefits of HFNOT. (5 marks)

Answer 43

Warmed humified gas: • Improved clearance of secretions • Decreased atelectasis **Dry, cold gas impairs ciliary function. High gas flow: • Washout of anatomical dead space • Patients require a lower minute ventilation to achieve the same alveolar ventilation. • Allows FiO2 close to 100% to be delivered A much higher FiO2 can be delivered due to reduced entrainment of air. ○ Positive end-expiratory pressure (PEEP): The evidence base for HFNOT remains small: HFNOT has been shown to be non-inferior to non-invasive ventilation in certain critical care patients. • Low level of PEEP delivered whether mouth open or closed • Increased functional residual capacity • Alveolar recruitment

Question 44

List four contraindications to the use of HFNOT. (4 marks)

Answer 44

• Type 2 respiratory failure • Unconscious patients • Uncooperative patients • Basal skull fracture **This could potentially result in pneumocephalus. • Epistaxis • Facial injury • Laser surgery **Most HFNOT equipment can only deliver 100% oxygen, which risks airway fire. • Airway/nasal obstruction

Question 45

Question 9. Fiona, a 32-year-old woman, is listed for a laparoscopic right adrenalectomy. An adrenal mass was found when she was investigated for hypertension, and there is a known family history of adrenal tumours. a) What is the most likely diagnosis? (1 mark)

Answer 45

Phaeochromocytoma

Question 46

List four substances that this type of adenoma commonly produces. (4 marks)

Answer 46

• Epinephrine/adrenaline • Norepinephrine/noradrenaline • Dopamine • Chromogranin A • Opioid peptides • Vasoactive intestinal peptide (VIP) • Adrenocorticotropin (ACTH) • Calcitonin • Somatostatin • Neuropeptide Y Any 4 Although phaeochromocytomas usually predominantly secrete noradrenaline or adrenaline, they are capable of secreting many other peptides.

Question 47

During the diagnostic work-up, a blood sample was taken to measure the concentration of a particular substance. What is this substance? (1 mark) Pheochromocytoma

Answer 47

○ Metanephrine ** The result of the metabolism of adrenaline by COMT. ○ Normetanephrine *The result of the metabolism of noradrenaline by COMT. Not acceptable: vanillylmandelic acid (VMA), the concentration of which is measured in a 24-hour urine collection

Question 48

(Pheo) List four specific measures that you will take to prepare Fiona for surgery. (4 marks)

Answer 48

• Arterial pressure control: phenoxybenzamine or doxazocin Phenoxybenzamine = non-selective, non-competitive, long-acting α-blocker Doxazocin = competitive, selective α1-blocker • Heart rate/arrhythmia control: selective β1-blockers (e.g.atenolol, bisoprolol, metoprolol) • Investigation of myocardial function: ECG, echocardiogram • Management of hyperglycaemia: e.g. metformin, gliclazide, insulin

Question 49

Intra-operatively, following surgical handling of the adenoma, the patient becomes hypertensive. List four pharmacological options to manage this. (4 marks)

Answer 49

• Magnesium sulphate *Magnesium sulphate is usually given prophylactically it inhibits adrenal catecholamine release and reduces α-adrenergic receptor sensitivity to catecholamines. • Phentolamine 1-5mg ivi **Phentolamine = reversible non-selective α-blocker, 1–2 mg bolus. • Sodium nitroprusside (SNP) 0.5-4mcg/kg/min/glyceryl trinitrate (GTN) **SNP and GTN are both nitric oxide donors, administered by infusion. • Nicardipine **Nicardipine =dihydropyridine Ca2+ channel antagonist, administered by infusion. • Esmolol **Esmolol = selective β1-Blocker, administered by infusion. Not acceptable: remifentanil – whilst it is effective in blunting haemodynamic response to laryngoscopy or pain, it is ineffective in treating hypertensive crises associated with tumour manipulation

Question 50

Pheo Name two health conditions which are associated with developing this type of adenoma. (2 marks)

Answer 50

• Multiple endocrine neoplasia (types 2A and 2B) • Von Hippel–Lindau disease • Neurofibromatosis • Succinate dehydrogenase enzyme deficiency

Question 51

Question 10. Jennifer is a 34-year-old woman who has been admitted with a dental abscess. She has no other past medical history of note, but on pre-operative examination, it is apparent that she cannot open her mouth more than 1 cm due to trismus. You have opted to perform an awake fibre-optic intubation (AFOI). a) What is the definition of a difficult airway? (1 mark)

Answer 51

• A clinical situation in which an anaesthetist experiences difficulty with facemask ventilation, supraglottic device ventilation, tracheal intubation or all three • >2 attempts at intubation using direct laryngoscopy (same or different blade) • Using adjuncts to direct laryngoscopy • Using an alternative device or technique following failed intubation with direct laryngoscopy **The Cormack and Lehane grades 3 and 4 relate to difficult laryngoscopy, as opposed to a ‘difficult airway’.

Question 52

b) Aside from patient refusal, list four contraindications to AFOI. (4 marks)

Answer 52

• Inexperienced operator AFOI may not be the best option if there is a potential to cause complete airway obstruction; the so-called cork-in-bottle situation, e.g. in glottic tumours where the aperture of the airway may be greatly reduced. • Impending airway obstruction (at risk of ‘cork-in-bottle’) • Allergy to local anaesthetic agents • Infection/contamination of the upper airway: blood, friable tumour, open abscess • Grossly distorted anatomy AFOI in patients with an obstructed airway remains controversial – NAP 4 reported failure of this technique in 14 out of 23 head and neck cases. • Fractured base of skull (contraindication to nasal route) • Penetrating eye injury • Uncooperative patient

Question 53

c) Complete the following table regarding laryngeal anatomy. (4 marks)

Answer 53

• Cricothyroid → tenses vocal cords • Thyroarytenoid and vocalis → slacken vocal cords The extrinsic laryngeal muscles are responsible for movement of the larynx as a whole. • Lateral cricoarytenoid and transverse arytenoids → adduction of vocal cords • Posterior cricoarytenoid → abduction of vocal cords The intrinsic laryngeal muscles (the transverse and oblique arytenoids and aryepiglottic muscles) adjust the aperture of the larynx.

Question 54

State the two nerves which innervate the muscles of the vocal cords. (2 marks)

Answer 54

• Recurrent laryngeal supplies all laryngeal muscles with the exception of cricothyroid muscle * The recurrent laryngeal nerve is a branch of the vagus nerve, with the right and left recurrent laryngeal nerves following differing paths. *The recurrent laryngeal nerve provides sensation to the subglottis. • External laryngeal nerve supplies the cricothyroid muscle * The external and internal laryngeal nerves arise from the superior laryngeal nerve, which itself arises from the vagus nerve. *The internal branch is the sensory supply to the glottis, supraglottis and inferior epiglottis.

Question 55

You have carefully consented Jennifer for an AFOI. Prior to commencing the procedure, you wish to calculate the maximum topical lignocaine dose that you can give. e) For AFOI, what is the maximum accepted dose of lignocaine (mg/kg)? (1 mark)

Answer 55

9 mg/kg 1 Based on lean body mass, for adults >50 kg. The maximum dose in children is lower, up to 4.5 mg/kg.

Question 56

What percentage of nebulised lignocaine is thought to be systemically absorbed during AFOI? (1 mark)

Answer 56

25% (accept 20%–30%)

Question 57

You have topically anaesthetised Jennifer’s supraglottic airway and have opted to perform a trans-tracheal block for subglottic topicalisation. g) Provide a brief description of how a trans-tracheal block is performed. (3 marks)

Answer 57

• Use of 21–23 G needle to pierce the cricothyroid membrane • Aspiration of air to confirm the tip of the needle is within the trachea Any 4 The resultant cough aids the spread of the local anaesthetic within the tracheobronchial tree.• Injection (ideally whilst patient exhaling) of lignocaine • Trans-tracheal lignocaine dose calculated taking into account the lignocaine already administered to topicalise the supraglottic airway • Rapid removal of needle to ensure no trauma when the patient coughs

Question 58

The surgery proceeds uneventfully. In accordance with Difficult Airway Society guidelines, you have optimised the patient for extubation. h) List four other preparations that you would make to ensure a safe extubation. (4 marks)

Answer 58

• Airway equipment for re-intubation on standby • Extubation in theatre with trained assistant • Appropriate anaesthetic drugs drawn up in the required doses in case of need for resedation/intubation • Verbalised management strategy in case of failed extubation • Surgical team remain in operating theatre until successful extubation has been established • A period of observation in theatre, before transfer to recovery The Difficult Airway Society guidelines recommend the following to optimise ‘patient’ factors: • Ensure cardiovascular stability • Ensure respiratory stability • Ensure metabolic/temperature stability • Ensure neuromuscular function has returned A ‘cuff-leak’ test is sometimes used to determine the relative safety of extubation – there is limited evidence for its value and it has not been shown to accurately predict post-extubation stridor. Given the topicalistion of her airway, Jennifer should be kept nil by mouth post- operatively until her risk of aspiration has returned to baseline

Question 59

Question 11. Bashir, a 76-year-old man, is admitted following an episode of colicky abdominal pain. Following investigation, the general surgeons suspect he has an obstructing sigmoid carci- noma and he is listed for a laparotomy. The patient has a history of dementia. a) List two common causes of dementia in the United Kingdom. (2 marks)

Answer 59

a • Alzheimer’s disease • Vascular dementia (accept multi- infarct dementia) • Lewy body dementia

Question 60

b) The surgeons have deemed the patient to lack capacity. List the four functional compo- nents which must be met for a patient to be deemed to have the capacity to make a decision. (4 marks)

Answer 60

• Understand the decision to be made and the information given 1 • Retain the information long enough to make the decision 1 • Weigh up the information given 1 • Communicate their decision

Question 61

c) According to the Mental Capacity Act 2005, if a patient lacks capacity and is unable to consent to a procedure, treatment is carried out in the patient’s best interests. List four aspects that should be considered when deciding what is in the patient’s best interests. (4 marks)

Answer 61

Assessment of best interests should include the following factors: Any 4 Family or close friends should be consulted to establish these factors for this patient. • Social • Psychological • Medical • Should be the least burdensome option • Should be informed by the patient’s attitudes and opinions

Question 62

d) With regard to future decision-making about health issues, list two legal options which the patient may have taken prior to the onset of dementia. (2 marks)

Answer 62

• Advanced directive/living will • Lasting Power of Attorney for Health and Welfare • Court-appointed deputy

Question 63

The laparotomy proceeds uneventfully, and the patient is admitted to the critical care unit post-operatively. Over the next 24 hours, his behaviour changes from ‘pleasantly confused’ to a fluctuating state of worsening confusion, aggression and inattention. e) Name the diagnosis (1 mark), and list four risk factors for developing this diagnosis. (4 marks)

Answer 63

Diagnosis: Post-operative delirium Risk factors: • Previous delirium • Dementia • Age > 70 years • Alcohol abuse • Visual impairment • Hearing impairment • Hypertension • Vascular surgery • Depression • Severe illness/major surgery

Question 64

f) The patient’s behaviour becomes sufficiently challenging to require pharmacological and physical restraint. List two factors that should be considered with regard to a Deprivation of Liberties Safeguarding application. (2 marks)

Answer 64

That a person: • Is confined to a restricted place for a non-negligible period of time • Lacks capacity to consent to their care • Is subject to continuous and complete supervision and control • Is not free to leave

Question 65

g) The patient develops a bronchopneumonia and does not respond to initial antibiotic treatment. A ‘not for cardiopulmonary resuscitation’ decision is being considered. No relatives or close friends have been identified – which other person should you involve in this decision? (1 mark)

Answer 65

Independent Mental Capacity Advocate (IMCA) 1 A medical decision can be made ‘in best interests’ if there is insufficient time to involve an IMCA.

Question 66

Question 12. Ruth, a 54-year-old woman, is listed for a deep inferior epigastric perforator (DIEP) free flap breast reconstruction. She has no past medical history other than a mastectomy 6 months previously. a) State the equation and factors that determine laminar flow of a Newtonian fluid. (3 marks)

Answer 66

Hagen–Poiseuille equation: Blood flow =ΔPπr4/8ηl where: ΔP is the pressure difference between the two ends of a tube r = radius of tube η = viscosity of fluid l = length of tube

Question 67

b) State three factors which affect blood viscosity, making it a non-Newtonian fluid. (3 mark)

Answer 67

Viscosity is not constant, but varies with • Flow rates *At low flow rates, viscosity increases – red blood cells aggregate into stacks (rouleaux formation). • Temperature *Hypothermia increases viscosity. • Haematocrit **A haematocrit of 0.3 is considered optimal.

Question 68

c) List four intra-operative strategies to promote free flap perfusion through vasodilatation. (4 marks)

Answer 68

• Maintaining normothermia **Hypothermia causes both vasoconstriction and an increase in viscosity. • Normovolaemia **Hypovolaemia causes vasoconstriction. • Anaesthetic agents **Propofol and volatile anaesthetics all cause vasodilatation. • Sympathetic blockade **Epidural or paravertebral blocks. • Minimise surgical handling of flap **Excessive surgical handling may precipitate vasospasm of the transplanted vessels. NB Pharmacological vasodilatation is rarely used, due to steal phenomenon from a maximally dilated flap circulation. They are only used to control excessive hypertension and typically to prevent/treat vaospasm.

Question 69

List two surgical and two non-surgical causes of free flap failure. (4 marks)

Answer 69

Surgical: ○ Arterial – vessel trauma, spasm, thrombus, technical problems with anastomosis • Venous – kinking of pedicle at anastomosis, spasm, thrombus, compression due to haematoma/dressings • Reperfusion injury due to prolonged ischaemic time (primary ischaemia,secondary ischaemia time ) ischaemia time holds be restricted to <3hr Non-surgical: • Oedema due to excess fluid administration, flap tissue has no lymphatics • Hypercoagulable state ○ Poor patient selection •Systemic vascular disease • Cardiac disease • Resp diseases and smoking • Collagen vascular disease • Obesity •Coagulopathy •advanced age

Question 70

The surgical operation note requests ‘clinical flap observations’. List six clinical methods for assessing the perfusion of the flap. (6 marks)

Answer 70

• Evaluation of flap colour • Capillary refill time • Skin turgor • Skin temperature • Bleeding on pinprick • Transcutaneous Doppler signal over perforator artery **Arterial ischaemia results in a cool, pale flap with slow capillary refill time, no bleeding on pinprick and loss of triphasic Doppler signal. In contrast, venous ischaemia results in a warm, congested, blue flap with short capillary refill time, rapid bleeding on pinprick and loss of venous Doppler signal.