CRQ Paper 5 Flashcards
Question 1. On a routine visit to his general practitioner, James, a 59-year-old man, is suspected to have a pituitary adenoma. He is referred to an endocrinologist, who subsequently undertakes multiple tests. The insulin-like growth factor 1 (IGF-1) is raised, and the oral glucose tolerance test (OGTT) failed to suppress an endogenous hormone. Magnetic resonance imaging of the brain confirms a pituitary macroadenoma. a) What is the visual field defect most commonly associated with a pituitary adenoma? (1 mark)
○ Bitemporal hemianopia
**Due to optic nerve compression at the optic chiasm.
On a routine visit to his general practitioner, James, a 59-year-old man, is suspected to have a pituitary adenoma. He is referred to an endocrinologist, who subsequently undertakes multiple tests. The insulin-like growth factor 1 (IGF-1) is raised, and the oral glucose tolerance test (OGTT) failed to suppress an endogenous hormone. Magnetic resonance imaging of the brain confirms a pituitary macroadenoma.
b) What is the diagnosis in this case? (1 mark) List five further clinical features of this disease. (5 marks)
Diagnosis: Acromegaly/growth hormone-
secreting pituitary macroadenoma
** In acromegaly, IGF-1 is chronically raised despite GH being elevated (IGF-1
should suppress GHsecretion). Giving the
patient a 75g glucose load should also suppress GH secretion.
Clinical features:
• Coarsening of facial features (frontal bossing, enlarged nose/ jaw/lips/ears, prognathism, increased interdental spacing, macroglossia)
• Soft tissue changes (increased
skin thickness, sweating, enlargement of hands and feet)
• Carpal tunnel syndrome *Often bilateral.
• Obstructive sleep apnoea *Due to macroglossia and pharyngeal soft tissue
growth.
• Sexual dysfunction (reduced libido, infertility, erectile dysfunction); oligomenorrhoea, galactorrhoea
Usually due to prolactin co-secretion by the adenoma, or by prolactin secretion as the pituitary stalk is compressed
by the adenoma.
• Headache
• Hypertension
• Type II diabetes mellitus
• Arthropathy
• Cardiomegaly/cardiomyopathy
• Vocal cord hypertrophy/
deepening of voice
c) List six hormones secreted by the anterior pituitary and state the hormonal trigger for their release. (6 marks)
○ ACTH triggered by hypothalamic
CRH release
○ melanocyte stimulating hormone
(MSH), as MSH is released from the intermediate lobe of the pituitary, located
between the anterior and posterior lobes.
• TSH triggered by hypothalamic TRH release
• FSH triggered by hypothalamic
GnRH release
• LH triggered by hypothalamic GnRH release
• GH triggered by hypothalamic GHRH release
• PRL triggered by decrease in hypothalamic dopamine release
*The hormones released bythe posterior pituitary are oxytocin and ADH
James is listed for a trans-sphenoidal resection of his pituitary adenoma. During the procedure, the surgeon struggles to reach the adenoma and would like you to aid the descent of the pituitary gland into the operative field.
d) Name two techniques by which this can be achieved. (2 marks)
• Controlled hypercapnoea
*Increases cerebral blood flow and thus intracranial pressure, pushing the
pituitary gland into the sella turcica.
• Injection of saline into a lumbar
drain
*Increases lumbar CSF pressure, and thus
intracranial pressure, again pushing the pituitary gland down into the sella turcica.
e) List two endocrine complications of pituitary surgery and two neurosurgical complications specific to trans-sphenoidal pituitary surgery. (4 marks)
Endocrine complications:
• Diabetes insipidus
*Usually resolves
spontaneously, but if it persists patients will require long-term desmopressin.
• Adrenocortical deficiency
*Patients are routinely given
a post-operative reducing
regime of corticosteroids,
adjusted according to post-operative hormonal function.
• Panhypopituitarism
*May occur following extensive pituitary
resection; thyroid and sex hormone replacement will also be required.
Neurosurgical complications: Any 2
• Cerebrospinal fluid leak/
rhinorrhoea
**This can be distinguished from mucous rhinorrhoea by testing nasal discharge
with a dipstick for glucose.
• Vascular injury (internal carotid artery within the cavernous sinus)
*The cavernous sinus surrounds the pituitary gland.
• Optic nerve injury
• Nasal septum perforation
• Anosmia due to cribriform plate
injury
• Post-operative sinusitis
f) Other than regular IGF-1 levels, what long-term follow-up will be needed after the procedure? (1 mark
Colonoscopy
*High risk of colorectal carcinoma.
b) State the valve area for each of the following classes of aortic stenosis severity. (4 marks)
• Bicuspid aortic valve
• Rheumatic heart disease
• Paget’s disease
• Fabry’s disease
• Systemic lupus erythematosus
Severity:
Mild: 1.2–1.8 cm2
Moderate: 0.8–1.2 cm2
Severe: 0.6–0.8 cm2
Critical: <0.6 cm2
*The pressure gradient can
also be used to describe
severity of aortic stenosis,
but severity is
underestimated once the left
ventricle starts to fail.
Mild: 12–25 mmHg
Moderate: 25–40 mmHg
Severe: 40–50 mmHg
Critical: >50 mmHg
Serena has had a recent echocardiogram showing severe aortic stenosis. Give four anaesthetic principles you would employ during her general anaesthetic specific to her cardiac physiology and the reasoning behind them. An example has been completed for you. (8 marks)
Principle → reasoning:
• Maintain sinus rhythm → dependent on atrial contraction for ventricular filling
• Avoid tachycardia/maintain heart rate < 90 beats/min → tachycardia reduces diastolic time and myocardial perfusion
• Avoid bradycardia/maintain heart rate > 60 beats/min → heart rate dependent due to fixed stroke volume
• Maintain diastolic blood pressure
(DBP) → ensure adequate coronary perfusionpressure (CPP)
CPP = DBP – left ventricular end-diastolic
pressure (LVEDP)
• Avoid reduction in systemic
vascular resistance (SVR) →
maintain blood pressure due to
fixed cardiac output (CO)
**Patients with severe aortic stenosis have a fixed cardiac output. They cannot
compensate for reductions
in SVR – this will result in severe hypotension, impaired myocardial perfusion and subsequently reduced contractility.
• Avoid increases in SVR → increases myocardial workload/ O2 requirement
• Maintain contractility/maintain
cardiac output → relatively fixed stroke volume
Remember:
CO = HR × SV
BP = CO × SVR
Serena has had a recent echocardiogram showing severe aortic stenosis. Give four anaesthetic principles you would employ during her general anaesthetic specific to her cardiac physiology and the reasoning behind them. An example has been completed for you. (8 marks)
Principle → reasoning: Any 8 One mark for each correct
principle, up to 4 marks; 1
mark for each reasoning, up
to 4 marks.
• Maintain sinus rhythm →
dependent on atrial contraction
for ventricular filling
• Avoid tachycardia/maintain
heart rate < 90 beats/min →
tachycardia reduces diastolic
time and myocardial perfusion
• Avoid bradycardia/maintain
heart rate > 60 beats/min → heart
rate dependent due to fixed
stroke volume
• Maintain diastolic blood pressure
(DBP) → ensure adequate
coronary perfusion
pressure (CPP)
CPP = DBP – left
ventricular end-diastolic
pressure (LVEDP
• Avoid reduction in systemic
vascular resistance (SVR) →
maintain blood pressure due to
fixed cardiac output (CO)
Patients with severe aortic
stenosis have a fixed
cardiac output. They cannot
compensate for reductions
in SVR – this will result in
severe hypotension,
impaired myocardial
perfusion and subsequently
reduced contractility.
• Avoid increases in SVR →
increases myocardial workload/
O2 requirement
• Maintain contractility/maintain
cardiac output → relatively fixed
stroke volume
Remember:
CO = HR × SV
BP = CO × SVR
d) Serena’s ECG shows left ventricular hypertrophy. What other abnormalities may be present on the ECG of a patient with severe aortic stenosis? (2 marks
• Heart block
• Left axis deviation
• ST depression/T-wave inversion in lateral leads (must specify leads)
• P-wave enlargement
**The aortic valve is very close
to the atrioventricular node:
calcification may result in
heart block.
Two months later, Serena is admitted to hospital generally unwell and is diagnosed as having infective endocarditis.
e) State two major and two minor criteria (as per the modified Duke criteria) that may be used in the diagnosis of infective endocarditis. (4 marks
Major:
• Positive blood cultures
• Positive echocardiogram finding
defined as
– Oscillating intracardiac mass
– Intracardiac abscess
– Partial dehiscence of prosthetic valve
**Infective endocarditis is an
infrequent and dynamic disease.
Minor:
• Predisposition (e.g. heart condition, IV drug use)
• Fever
• Vascular/immunological
phenomena, such as:
– Arterial emboli
– Septic infarcts
– Mycotic aneurysm
– Intracranial haemorrhage
– Conjunctival haemorrhages
– Janeway lesions
• Other microbiological evidence,
such as PCR/serological tests
Transoesophageal
echocardiography should be
used in all patients.
**Despite modern medical
and surgical therapy, it is
still associated with high
rates of complications and
increased mortality. Early
surgery is becoming more
common, and a
multidisciplinary team approach is vital.
Question 3.
a) What percentage of major airway events reported to the National Audit Project (NAP) 4 originated during critical care intubation? (1 mark)
20%–30%
*25% in NAP4
b) List six patient-related factors that increase the risk of complications during the intubation of critical care patients. (6 marks
• Aspiration risk: critical care patients are often not adequately fasted
• Difficult airway: airway assessment is often challenging
• Inadequate preoxygenation: the
patient may already have
significant hypoxaemia
• Agitation/confusion may impair
preoxygenation
• Respiratory pathology, e.g. shunt/pulmonary infection causing V̇ /Q̇ mismatch
• Cardiovascular impairment: contributing to V̇ /Q̇ mismatch
• Difficult patient positioning
** There are numerous reasons
why airway interventions in critical care are more likely to be difficult. These can be
categorised as
1. Environmental/location factors, e.g. critical care is isolated from certain pieces
of anaesthetic equipment.
2. Patient factors, as discussed.
3. Staff factors.
Experience of assisting with smaller
number of intubations means that critical care nursing staff tend to be
relatively deskilled compared to anaesthetic assistants.
The ‘MACOCHA’ score has been validated for airway assessment in critically ill patients.
c) List four of the components considered in the MACOCHA score. (4 marks)
State the MACOCHA score that predicts a difficult intubation. (1 mark)
The MACOCHA score comprises seven
components in three domains, with a maximum score of 12. It is the only
airway assessment score which has been validated in critically ill patients
Factors relating to the patient:
• Mallampati class III or IV (score = 5)
• Obstructive sleep Apnoea syndrome
(score = 2)
• Reduced mobility of Cervical spine
(score = 1)
• Limited mouth Opening < 3 cm (score = 1)
Factors relating to pathology:
• Coma (score = 1)
• Severe Hypoxaemia (SpO2 < 80%) (score = 1)
Factors relating to operator:
• Non-Anaesthetist (score = 1)
**A MACOCHA score > 3 predicts
difficult intubation in the critically ill
d) List four indications for tracheostomy in critical care patients. (4 marks
• Long-term mechanical ventilation
• Failed extubation/failure of weaning from the ventilator
* Prolonged weaning is often defined as weaning lasting longer than 7 days after the first spontaneous breathing
trial.
• Upper airway obstruction
• Difficult airway
* Cricothyroidotomy is preferred as an airway rescue technique as it is
technically easier to perform and is associated with less bleeding.
• Need for airway access for tracheal toilet
• Airway protection
e) List four patient-related relative contraindications to percutaneous tracheostomy in critical care patients. (4 marks)
• Coagulopathy
• Significant gas exchange deficiency (positive end-expiratory pressure ≥ 10 cmH2O, fraction of inspired oxygen ≥ 0.6)
• Infection at insertion site
• Difficult anatomy (accept maximum of two from: short neck, cervical spine injury,
limited neck movement, aberrant
vessels, thyroid pathology)
Question 4. Ben, a 2-year-old boy with a history of severe cerebral palsy, presents for insertion of a percutaneous endoscopic gastrostomy (PEG) under general anaesthesia.
a) List two antenatal and two postnatal risk factors for the development of cerebral palsy. (4 marks)
Antenatal:
• Prematurity (<32 weeks gestation)
• Multiple births
• Low birth weight (<2.5 kg)
• Intrauterine ‘TORCH’ infections:
toxoplasmosis, varicella, rubella,
cytomegalovirus, herpes (accept maternal infection)
• Foetal alcohol syndrome
• Congenital metabolic syndrome
• Maternal hyperthyroidism
*Antenatal causes account for ~80% of cases of cerebral palsy.
Postnatal:
• Neonatal jaundice/kernicterus
• Birth complications: placental abruption, uterine rupture, pre-eclampsia, hypoxic injury
• Events in the first 2 years of life:
trauma, cerebral infection,
cerebral haemorrhage/infarction,
seizures
b) List three clinical features that may occur in severe cerebral palsy related to the central nervous system (3 marks), and for each, state the anaesthetic implications. (3 marks)
• Learning difficulties → pre-operative anxiety
• Communication difficulties:
expressive language disorders,
motor problems affecting speech/
visual/auditory impairment →
difficult to communicate anxiety
and pain
• Epilepsy → antiepileptic drugs
may cause enzyme induction/
inhibition, reduce MAC by 30%,
cause sedation/slower recovery
from anaesthesia
• Abnormal pain perception →
post-operative pain may be
difficult to manage
• Spasticity → difficulty
positioning
List two clinical features that may occur in severe cerebral palsy related to the gastrointestinal system (2 marks), and for each, state the anaesthetic implications. (2 marks)
• Gastro-oesophageal reflux →
risk of aspiration pneumonia on
induction of anaesthesia
• Pseudo-bulbar palsy, leading to
drooling and poor nutrition →
dehydration, anaemia,
electrolyte disturbance
• Oesophageal dysmotility →
aspiration pneumonia, poorly
compliant chest
Overnight supplementation
of nutrition via a
nasogastric tube or PEG is
common in this patient
group. Surgical
fundoplication may be
required to control gastro-
oesophageal reflux.
List two clinical features that may occur in severe cerebral palsy related to the respiratory system (2 marks), and for each, state the anaesthetic implications. (2 marks)
• Repeated aspiration pneumonia
→ chronic lung disease/lung
scarring
• Prematurity → chronic lung
disease secondary to infant
respiratory distress syndrome
• Scoliosis → restrictive lung
deficit, pulmonary hypertension
• Respiratory muscle hypotonia →
poor cough, recurrent infection
*Muscle spasms promote the
development of scoliosis,
which may ultimately lead
to pulmonary hypertension
and respiratory failure.
e) The patient takes regular baclofen to control muscle spasms. What are the mechanism and site of action of baclofen? (2 marks
Mechanism:
GABAB receptor antagonist, inhibits
release of aspartate and glutamate
Site of action:
Dorsal horn of spinal cord (Rex
laminae II and III)
** Baclofen can be given orally
or intrathecally through a
subcutaneously implanted
infusion device.
Question 5. You are asked to complete a telephone follow-up for Amali, a 32-year-old woman, who underwent an elective caesarean section under spinal anaesthesia 2 days ago. Following discharge, she has developed a severe headache.
a) List six clinical features of a post-dural puncture headache (PDPH). (6 marks)
• Frontal-occipital headache
• Worse in the upright position
• Positive Gutsche sign
• Nuchal rigidity
• Photophobia
• Tinnitus
• Visual disturbance
• Cranial nerve palsies
*The International Headache Society defines PDPH as one attributed to low
cerebrospinal (CSF) pressure, developing within 5 days of neuraxial blockade and remitting spontaneously within 2 weeks or following an epidural blood patch.
*Gutsche sign is when right upper quadrant abdominal pressure results in temporary improvement of the headache.
b) List six other differential diagnoses of a post-partum headache. (6 marks)
• Non-specific/tension headache
• Migraine
• Pre-eclampsia
• Cortical vein thrombosis
• Subarachnoid/subdural
haemorrhage
• Posterior reversible
leukoencephalopathy syndrome
• Space occupying lesion
• Infection – encephalitis,
meningitis, sinusitis
*The mechanism of headache
in PDPH is explained by the
loss of CSF. This results in
compensatory
vasodilatation of cerebral
vessels and leads to traction
on the pain sensitive
intracranial vasculature.
Clinical features of serious
pathology should always be
sought.
c) What steps can you take when performing a spinal anaesthetic to reduce the risk of PDPH? (4 marks
• Needle size: smaller gauge
• Needle type: pencil point over
Quincke
• Re-insertion of stylet prior to
removal of spinal needle
• Experienced operator
• Other techniques to optimise
single pass success, such as
optimal positioning, use of
ultrasound
*The incidence of PDPH
following spinal
anaesthesia has fallen due
to the widespread adoption
of smaller-gauge, pencil-
point spinal needles.
Due to childcare commitments, Amali is unable to present to the hospital for review as per your advice.
d) List four serious complications of untreated PDPH. (4 marks)
• Cerebral venous sinus thrombosis
• Cranial nerve palsies
• Subdural haematoma
• Brainstem compression
• Death
• Persistent CSF leak/chronic headache/intracranial hypotension
** A recent MBRRACE report
highlighted two deaths in
women with PDPH,
although both cases were
related to inadvertent dural
puncture during epidural
insertion.
All patients with PDPH
should be followed up,
regardless of management.
Question 6.
Heather, a 76-year-old woman with metastatic pancreatic cancer, is referred to the pain clinic by her general practitioner. Her current medication includes paracetamol, gabapentin, modified-release morphine and oral morphine. Your consultant is planning to perform a coeliac plexus block.
a) Which three sympathetic nerves unite to form the coeliac plexus? (3 marks)
Greater splanchnic nerve
*Sympathetic fibres from T5
to T9.
Lesser splanchnic nerve
** Sympathetic fibres from
T10 to T11.
Least splanchnic nerve
*Sympathetic fibres from T12.
**The coeliac plexus also
receives parasympathetic
input from the coeliac
branch of the vagus nerve.
d) Using the posterior approach, describe how you would perform a coeliac plexus block. (6 marks)
Preparation:
• AAGBI-recommended standard
monitoring
• Intravenous access
• Resuscitation equipment
available
• Trained assistant
• Stop before you block
Block specific:
• Prone position
• X-ray screening (fluoroscopy) or
CT guidance
• Needle entry point: just below
12th rib
• Advance needle until it hits L1
vertebral body
• Withdraw needle and redirect to
pass L1 vertebral body
• Radio-opaque dye injected to
confirm correct placement
• Neurolytic agent injected
Question 7.
Doug, a 45-year-old man, presents to the Emergency Department having taken 80 of his antidepressant tablets. The emergency medicine physicians feel he is showing signs of serotonin syndrome.
a) What is serotonin syndrome? (1 mark)
A potentially life-threatening
condition associated with increased
serotonergic activity in the central
nervous system
**The main differential diagnosis is neuroleptic malignant syndrome, which
is slower in onset and has a higher mortality. Dopamine agonism produces bradykinesia whereas serotonin agonism produces hyperkinesia.
c) List six of the Sternbach criteria for the diagnosis of serotonin syndrome. (6 marks)
Major criteria:
• Recent addition or increase in a known serotinergic agent
• No recent addition or increase of a neuroleptic agent
• Absence of other possible aetiologies
Minor criteria
• Mental status changes (confusion, hypomania)
• Agitation
• Myoclonus
• Hyperreflexia
• Diaphoresis
• Shivering
• Tremor
• Diarrhoea
• Incoordination
• Fever
**Serotonin syndrome is a clinical diagnosis by means
of the Sternbach diagnostic criteria – there are no
confirmatory laboratory or radiological tests to confirm or refute diagnosis.
The diagnosis can be made when all the major and three of the minor criteria are present.
b) List three classes of chemotherapy agent. (3 marks)
• Alkylating agents e.g. cyclophosphamide,
cisplatin
• Anti-metabolites E.g. methotrexate,
5-fluorouracil
• Topoisomerase interactive agents E.g. irinotecan, doxorubicin, bleomycin
• Anti-microtubule agents E.g. paclitaxel
• Hormonal agents E.g. anastrazole, luteinising hormone-releasing hormone analogues
• Tyrosine kinase inhibitors/ antibody agents E.g. trastuzumab
Question 9.
Rhys, a 32-year-old pedestrian, has been struck by a passing car. He has an open left tibial fracture and abdominal pain. His observations in the resuscitation room are heart rate 126 beats/min, blood pressure 72/43 mmHg, respiratory rate 34 breaths/min, Glasgow Coma Score 15/15.
a) List six management priorities in the resuscitation of this patient prior to diagnostic imaging. (6 marks)
• Primary trauma survey
• Cervical spine immobilisation
• Wide-bore intravenous access
• Group O negative blood
• Send blood samples to the
laboratory
• Cross-match blood
• Permissive hypotension
• Oxygen therapy (target
saturations > 95%)
• Activate major haemorrhage
protocol
• Analgesia
• Assess neurovascular status of
left lower limb
• Patient warming
• Intravenous tranexamic acid
• Orthopaedic review
• General surgical review
**This patient’s observations
suggest severe
haemorrhagic shock and
likely require resuscitation
with blood products (not
crystalloid). Blood samples
should be sent to the
laboratory as soon as
possible.
b) Name two investigations to help diagnose a splenic rupture. For each investigation, state the findings consistent with splenic rupture. (4 marks)
• Focussed Abdominal with
Sonography in Trauma (FAST)
scan → hypoechoic rim around
spleen; fluid in Morrison’s pouch
(hepatorenal space)
• CT abdominal scan →
haemoperitoneum; hypodense
areas in spleen represent
parenchymal disruption; contrast
blush or extravasation
Question 10. Wilf, a 72-year-old man, attends pre-operative clinic. He is listed for a laparoscopic sigmoidectomy for cancer. He has Parkinson’s disease.
a) What are the three clinical features that make up the classic triad of Parkinsonism? (3 marks)
• Bradykinesia
• Muscle rigidity
• Asymmetric resting tremor
The diagram below is taken from a normal capnography trace
• Phase two: both dead space AND
alveolar gas expired
• Phase three: alveolar gas expired
End-tidal CO2 is determined at the
end of phase three – see diagram
** If alveoli contained the
same partial pressure of
CO2, phase three would be a
straight line. However,
alveoli with lower V̇ /Q̇
ratios/longer time constants
contribute to the slight
upward slope seen.
d) Which gases (dead space and/or alveolar) are expired during phases 2 and 3? (2 marks)
Indicate on the diagram where end-tidal CO2 is determined. (1 mark
If alveoli contained the
same partial pressure of
CO2, phase three would be a
straight line. However,
alveoli with lower V̇ /Q̇
ratios/longer time constants
contribute to the slight
upward slope seen.
f) How can a Severinghaus electrode be used to measure the partial pressure of CO2 in solution? (3 marks
• CO2 diffuses across semi-
permeable/rubber/Teflon
membrane
• Dissociates into hydrogen ions
• Hydrogen ions are produced in
proportion to the PCO2
• Measured by pH electrode/
potential difference generated
between sample and buffer
solution
Question 12.
A recent meta-analysis of studies of the utility of the Mallampati score in the prediction of adifficult airway found that it had a sensitivity of 60% and a specificity of 70%.
a) What is meant by the sensitivity of a clinical test (1 mark), and how is it expressed mathematically? (2 marks)
Sensitivity refers to the ability of the
clinical test to correctly identify those
patients with a difficult airway
1 Two marks for correct formula
Sensitivity = True positives divided by
True positves plus false negatives 2
b) What is meant by the specificity of a clinical test (1 mark), and how is it expressed mathematically? (2 marks)Forest plot is:___________________________________________________________ Square represents:_______________________________________________________ ______________________________________________________________________ Diamond represents:
Specificity refers to the ability of the
clinical test to correctly identify those
patients without a difficult airway
Specificity ¼ True negatives
True negatives þ false positives
