CRQ Paper 3 Flashcards
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)
- Shoulder abduction = C5
**Mnemonic: ‘C5/6 – pick up sticks
** C7/8 keep it straight’ - Elbow flexion = C6
** - Elbow extension = C7
- Finger abduction = T1
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)
○ 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
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)
• 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.
List two precautions you would take when intubating this patient. (2 marks)
• 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.
(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)
• 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 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)
• 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.
Based on the history provided above, what is Insiyas percentage risk of perioperative cardiac
complications? (1 mark)
○ 6.6% (accept 6–7%)
○ Insiya scores two: one for ‘ischaemic heart disease’ and one for ‘high-risk
surgery
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
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
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)
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
(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)
Cardiogenic shock (accept cardiac/
left ventricular failure)
(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)
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)
(Perioperative MI, cardiogenic shock)
What non-pharmacological treatment options could be considered? (3 marks)
• Intra-aortic balloon pump
**In a non-cardiac centre, these options may not be readily available!
• Urgent revascularisation
• Left ventricular assist device
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)
• 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
b) What is the maximum dose of propofol (mg/kg/h) that should be used as an infusion?
(1 mark
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.
In addition to a high-dose propofol infusion, list four risk factors for developing PRIS.
(4 marks)
• 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
What specific laboratory findings might be expected in a case of PRIS? (3 marks)
• 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
(PRIS)
List four aspects of your clinical management of this case. (4 marks)
• 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.
What is the mortality from PRIS? (1 mark)
Literature estimates range from 4%
to 18%
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)
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%).
List six features of this child’s physical appearance that are characteristic of Down’s
syndrome. (6 marks)
• 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
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)
• 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
Which haematological malignancy are children with Down’s syndrome particularly
susceptible to? (1 mark
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.
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)
○ 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 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.
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.
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)
• 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.
c) State the two main theories hypothesised in the mechanism of AFE. (2 marks)
- Mechanical/embolic
- Immunological
Both theories hypothesise
exposure of the maternal
circulation to amniotic fluid or foetal antigens.
A biphasic response to AFE is commonly described. What are the two key features of the
phase 2 response? (2 marks)
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.
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)
• 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 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)
i = Vertebral body
ii = Pedicle
iii = Lamina
iv = Spinous process
v = Superior articular process (accept
facet joint)
vi = Central spinal canal
List five features in the history and five clinical signs that would suggest serious spinal
pathology. (10 marks)
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
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)
○ 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.
(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)
• 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 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)
○ 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
List six factors associated with an increased likelihood of AAGA. (6 marks)
• 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.
How will you manage this clinical situation? (3 marks) awareness
• 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.
List four methods that can be used to monitor depth of anaesthesia. (4 marks)
• 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
e) Regarding the depth of anaesthesia, state electroencephalogram (EEG) wave patterns
consistent with wakefulness, surgical anaesthesia and excessive anaesthesia. (3 marks)
○ 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 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)
• 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.
b) Other than HFNOT, list two strategies to maintain oxygenation during an upper airway
panendoscopy. (2 marks)
• Microlaryngoscopy tube and intermittent positive pressure ventilation
• Supraglottic jet ventilation
• Subglottic jet ventilation
• Trans-tracheal jet ventilation
c) How will you maintain anaesthesia during this case? (1 mark)
○ Total intravenous anaesthesia
*It is not possible to deliver volatile anaesthetic agents
using HFNOT.
Regarding gas delivery, list two differences between HFNOT and conventional nasal
cannulae. (2 marks)
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.
State two other perioperative uses of HFNOT. (2 marks)
• 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.
List five physiological benefits of HFNOT. (5 marks)
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
List four contraindications to the use of HFNOT. (4 marks)
• 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 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)
Phaeochromocytoma
List four substances that this type of adenoma commonly produces. (4 marks)
• 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.
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
○ 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
(Pheo)
List four specific measures that you will take to prepare Fiona for surgery. (4 marks)
• 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
Intra-operatively, following surgical handling of the adenoma, the patient becomes hypertensive. List four pharmacological options to manage this. (4 marks)
• 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
Pheo
Name two health conditions which are associated with developing this type of adenoma.
(2 marks)
• Multiple endocrine neoplasia
(types 2A and 2B)
• Von Hippel–Lindau disease
• Neurofibromatosis
• Succinate dehydrogenase
enzyme deficiency
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)
• 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’.
b) Aside from patient refusal, list four contraindications to AFOI. (4 marks)
• 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
c) Complete the following table regarding laryngeal anatomy. (4 marks)
• 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.
State the two nerves which innervate the muscles of the vocal cords. (2 marks)
• 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.
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)
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.
What percentage of nebulised lignocaine is thought to be systemically absorbed during
AFOI? (1 mark)
25% (accept 20%–30%)
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)
• 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
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)
• 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 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)
a • Alzheimer’s disease
• Vascular dementia (accept multi-
infarct dementia)
• Lewy body dementia
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)
• 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
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)
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
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)
• Advanced directive/living will
• Lasting Power of Attorney for
Health and Welfare
• Court-appointed deputy
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)
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
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)
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
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)
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 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)
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
b) State three factors which affect blood viscosity, making it a non-Newtonian fluid.
(3 mark)
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.
c) List four intra-operative strategies to promote free flap perfusion through vasodilatation. (4 marks)
• 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.
List two surgical and two non-surgical causes of free flap failure. (4 marks)
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
The surgical operation note requests ‘clinical flap observations’. List six clinical methods for assessing the perfusion of the flap. (6 marks)
• 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.
