CRQ paper 2 Flashcards
Question 1. Julian, a 43-year-old roofer, has fallen from the roof of a two-storey building. He sustains a series of cervical spinal fractures. An anterior–posterior cervical fixation is planned with intra-operative spinal cord monitoring. a) Name the two types of spinal cord monitoring. (2 marks)
○ Motorevokedpotentials (MEPs)
○ Somatosensory evoked,potentials (SSEPs)
Volatile anaesthetics and nitrous oxide depress the amplitude of SSEPs and MEPs
Muscle relaxants (fullparalysis) make MEPs useless
***A normal dose of muscle relaxant at induction of anaesthesia is acceptable. Traditionally,alow muscle relaxant infusion titrated to 1–2 twitches is then used, but now,more commonly,a remifentanil infusion is used to facilitate intraoperative ventilation.
b) List two anaesthetic consequences specific to cases involving intra-operative spinal cord monitoring. (2 marks
- Volatile anaesthetics and nitrous
oxide depress the amplitude of SSEPs
and MEPs - Muscle relaxants (full paralysis) make MEPs useless
**A normal dose of muscle relaxant at induction of anaesthesia is acceptable.
Traditionally, a low muscle relaxant infusion titrated to 1–2 twitches is then used, but now, more commonly, a
remifentanil infusion is used to facilitate intra-operative ventilation.
List four options for body support of the patient when in the prone position. (4 marks)
Pillows
•Chest/pelvic bolsters
•Allen/Jackson table: A frame in which the patientis supported by a chest block and iliac crest/ thigh supports.
•Montreal mattress: A foam mattress with a cut out for the abdomen.
•Wilson frame: The Wilson frame is used for lumbar surgery: a winding mechanism increases the radius of curvature, thus reducing lumbar lordosis.
•Knee–chest position
d) List four neurological complications of the prone position. (4 marks
• Brachial plexus injury.
- If head is turned to right/ left,or shoulders abducted > 90°angle.
•Post-operative visual loss
- Most commonly due to ischaemic optic neuropathy and central retinal artery occlusion.
•Peripheral nerve injury
•Spinal cord injury
- Rolling with unstable fractures,or with over extension or over-flexion of the cervical spine.
•Increased intracranial pressure
- Due to obstruction of cerebral venous drainage (headrotated/notneutral).
•Ischaemic stroke/spinal cord ischaemia as a result of hypotension
) Inadequate prone positioning may lead to abdominal compression. List six nonneurological complications of abdominal compression in the prone position. (6 marks
• Reduced cardiac output/ hypotension dueto inferior venacava compression leading to reduced preload
•Intra-operative venous bleeding due toraised epidural venous pressure
•Lower limb venous thrombosis dueto inferior vena cava compression
•Decrease in respiratory compliance
•Decreased left ventricular compliance due to raised intrathoracic pressure
•Acute kidney injury
•Increased intragastric pressure
•Acute liver injury/metabolic acidosis
f) During the case, whilst in the prone position, Julian is accidentally extubated. What would first alert you to this problem, and how would you initially manage the airway? (2 marks)
Alert: Ventilator signals a ‘low-pressure’ alarm/reservoir bag empties/surgical admission of guilt
Manage airway: Insert a laryngeal mask airway Bag–mask ventilation
Lawrence, a 56-year-old man, is listed for an elective laparoscopic cholecystectomy for gallstone disease. He received an orthotopic heart transplant 12 years previously.
List four physiological perioperative implications of a denervated heart. (4 marks)
• Resting heart rate 90–100 beats/min
• Baroreceptor reflex lost hypotension does not trigger tachycardia
•Laryngoscopy does not cause tachycardia
•Pneumoperitoneumdoes not cause reflex bradycardia
•Changes inheart rate are no longer an indicator of depth of anaesthesia
•Cardiac output is dependent on adequate preload
•Cardiac dysrhythmias are more common
b) List four pharmacological perioperative implications of a denervated heart. (4 marks)
Vagolytics:
•Atropine and glycopyrrolate have no effect on heart rate
Inotropic/chronotropicdrugs:
•Increased sensitivity to adrenaline and noradrenaline
•No effect of indirectly acting sympathomimetics,e.g. ephedrine
Antiarrhythmics:
•Marked sensitivity to adenosine dose reduction needed
•Digoxin is ineffective for the treatment of atrial fibrillation
Other:
•No reflex tachycardia with glyceryl trinitrate
•No bradycardia with neostigmine or suxamethonium
c) List two pre-operative investigations that you would request for this patient. (Postcardiac transplant for non-cardiacsurgery) (2 marks)
•Recent echocardiogram to assess graft function •ECG
•CMV status
•Electrolytes
List the anaesthetic considerations specific to the previous cardiac transplant. (4 marks)
•Awake arterial line
•Central venous line
•Aim for normovolaemia prior to induction of anaesthesia
•Maintain coronary perfusion pressure/correct hypotension
•Scrupulous asepsis for lines and urinary catheter
•Availability of chronotropic/ inotropic drugs, and external pacemaker
•Immunosuppression therapy should be continued perioperatively
Lawrence currently takes tacrolimus and mycophenolate mofetil (post cardiac transplant). How will you manage the patient’s immunosuppression in the perioperative period? (3 marks)
○ Mycophenolate and tacrolimus should both be given in the morning before surgery.
○ Patient first on the list/timing to reduce risk of missed doses
○ Liaison with transplant team regarding immunosuppression
Both drugs have parenteral preparation in the event of impaired gastrointestinal absorption
*Drug levels–drug concentrations may be increased or decreased through drug–drug interactions
List three long-term health issues that may occur as a result of receiving a cardiac transplant. (3 marks)
• Chronic allograft vasculopathy (CAV, accelerated coronary atherosclerosis)
• Malignancy, mainly skin cancers
• Renal failure
• Diabetes mellitus
• Opportunistic infections, e.g. Pneumocystis jirovecii
• Hypertension
**CAV is thought to take place through a chronic rejection mechanism.
Renal failure and diabetes are side effects of the immunosuppressive agents.
New hypertension may occur secondary to anti-rejection drugs.
Question 3.
a) Which body is responsible for regulating and overseeing organ donation in the UK? (1 mark)
NHS blood and transplant
What is the UK definition of death? (1 mark)
The irreversible loss of the capacity for consciousness, combined with the irreversible loss of the capacity to breathe
List the four preconditions that need to be met prior to brainstem death testing. (4 marks)
•Irreversible structural brain damage of known aetiology causing unresponsive coma.
•The absence of any depressant drugs or neuromuscular blocking agents
•Normothermia (i.e.core temperature>34°C)
•No significant metabolic disturbances (i.e.normal blood sugar and electrolytes
d) At what stage during the brainstem testing process is the legal time of death? (1 mark)
At the end of the first set of brainstem death tests
**Two complete sets of tests need to be performed but the recorded time of death is at the end of the first set.
List four common physiological derangements that may occur following brainstem death in individuals awaiting organ donation. (4 marks) For each, explain the pathophysiological cause. (4 marks)
•Hypothermia→hypothalamic damage leading to reduced metabolic rate, vasodilatation and heat loss
*Heat-generting metabolic processes are reduced.
•Hypotension→vasoplegia; hypovolaemia; reduced coronary blood flow leading to myocardial dysfunction
•Diabetes insipidus→posterior pituitary damage as a result of raised intracranial pressure
• Disseminated intravascular coagulation(DIC) →tissue factor release leading to wides pread coagulation *Coagulopathy is common following isolated head injury (occurs in upto one third of patients).
** Following brainstem death, tissue thromboplastin is released from the necrotic brain, which contributes to DIC. •Arrhythmias→‘catecholamine storm’ leading to myocardial damage
**Raised intracranial pressure causes an increase in sympathetic nervous system activity,as the brain attempts to maintain cerebral perfusion pressure. After the catecholamine storm,there is a loss of sympathetict one, leading to peripheral vasodilatation and hypotension.
If untreated, this leads to organ hypoperfusion, including the heart,and may contribute to rapid donor loss.
•Pulmonary oedema→acute blood volume diversion, pulmonary capillary damage
f) Describe the normal physiological response to hypercapnoea (PaCO2 > 6.0 kPa). (4 marks)
•CO2 diffuses across blood–brain barrier into the cerebrospinal fluid
•Fall in CSF pH stimulates the central chemoreceptors
•Peripheral chemoreceptors in the carotid body and aortic arch detect changes in arterial PaCO2 and pH
•Peripheral chemoreceptors send afferent impulses via the glossopharyngeal and vagus nerves
•Central chemoreceptors play a greater role than peripheral chemoreceptors in the control of ventilation, but the response to peripheral chemoreceptors is more rapid
•The medullary respiratory centre is stimulated to increase the rate and depth of ventilation.
Prior to performing the apnoea test, an arterial blood gas confirms a PaCO2 of 6.0 kPa. g)
What is the minimum increasein PaCO2 required to confirm apositive a pnoea test?(1mark)
0.5kPa (accept0.5–0.65kPa)
Question 4.
Andrew, a 9-month-old boy, is brought by paramedics to the Emergency Department. You are asked to assess him as he is lethargic and is only responsive to painful stimuli. His mother is in attendance and is reluctant to allow nursing staff to undress the child. On examination, there are several bruises on the child’s arms and legs of differing ages. You suspect non-accidental injury (NAI). a) List the four categories of child abuse. (4 marks)
aPhysical
Sexual
Emotional
Neglect
b) List six risk factors for child abuse. (6 marks)
Child-relatedfactors:
•Chronic disability/illness
•Prematurity/lowbirthweight
•Unplanned/unwanted child
•Learning difficulties/behavioural problems
Parental factors:
•Step parent
•Teenageparent
•Substanceabuse
•Parent abused as a child
•Disabled parent
•Mental health problems
Familyfactors:
•Single-parent family
•Domestic violence
Social factors:
•Unemployment
•Poverty
•Isolation
c) Aside from NAI, what is your differential diagnosis of this patient’s clinical presentation? (6 marks)
Neurological:
•Seizure/febrile seizure/post-ictal state
•Central nervous system infection
•Intracerebral haemorrhage/ diffuse axonal injury
•Hydrocephalus
Infective:
•Sepsis
Metabolic:
•Hypo/hyperglycaemia
•Hepatic encephalopathy Poisoning: •Drugs,alcohol
d) With whomshould you discuss your child safe guarding concerns? (1 mark)
•Consultant anaesthetist •Person with level 3 child safe guarding competencies
•On-call paediatrician
e) State the type of staff that should be undertaking each of the following levels of child protection training, patient contact, give an example of a member of theatre staff.(3marks)
•Level 1= administrative and clerical staff with paediatric patient contact, e.g.theatre reception is example
•Level 2 = all clinical staff with paediatric patient contact,e.g. scrub nurse, anaesthetist
•Level 3 = clinical staff with extensive and regular contact with paediatric patients, and have a level of responsibility in assessing, planning and evaluating patient needs when safe guarding concerns are raised. E.g.lead paediatric anaesthetist, tertiary paediatric anaesthetist
Question 5. Dani is a 32-year-old woman who is 26weeks pregnant and is found to have a blood pressure (BP) of 160/104 mmHg in antenatal clinic. Her booking BP was 122/74 mmHg. Her urine dipstick is negative for protein, and she is diagnosed with gestational hypertension.
a) List four diagnostic criteria for gestational hypertension. (4 marks)
•Sustained increase in BP •BP≥140/90mmHg
•After 20 weeks gestation
•Previously normotensive patient
Dani is admitted to the ward for BP control and commenced on oral labetalol. A history of hypertension in a previous pregnancy means she is at high risk of pre-eclampsia, and she is commenced on aspirin. b) State three other medical conditions which increase a woman’s risk of developing pre-eclampsia. (3 marks)
•Chronic kidney disease
•Autoimmune disease such as systemic lupus erythematosus or antiphospholipid syndrome
•Pre-existing diabetes mellitus
•BMI>35kg/m2
Dani’s BP is managed with oral labetalol and preparations are made to discharge her home. She is advised to seek immediate advice if she experiences symptoms of pre-eclampsia. c) List four common symptoms of pre-eclampsia. (4 marks)
•Severe headache
•Visual problems such as blurring or flashing before the eyes
•Subcostal pain/ liver tenderness
•Vomiting
•Sudden swelling of the face, hands or feet
*Severe pre-eclampsiais diagnosed when thereis proteinuria withsevere hypertension (≥160/100 mmHg)or when there is hypertension(≥140/90 mmHg)plus one of these clinical features.
Onasubsequent admission, Dani is found to have a BP of 157/110 mmHg with significant proteinuria, and a diagnosis of pre-eclampsia is made
d) What is the definition of significant proteinuria? (1 mark)
•Urinary protein :creatinine ratio >30
•24-hour urine protein collection >300mg
Question7.
You are asked to anaesthetise Victoria,
a 65-year-old woman with long-standing rheumatoid arthritis, for atotal knee replacement.
She takes prednisolone 15mg daily.
a)Other than the knee joint, list two joints which are commonly affected in rheumatoid arthritis.(2marks)
•Proximal inter-phalangeal (PIP)
•Metacarpophalangeal (MCP)
•Wrists
•Shoulders
•Neck
•Elbows
•Ankles
c) List the extra-articular features of rheumatoid arthritis,and for each feature, state the anaesthetic relevance.(10marks
Respiratory
•Fibrosing alveolitis→restrictive lung deficit
•Costochondral disease→ reducedchestwall compliance *Approximately 50% of rheumatoid arthritis patients have extra articular disease.
•Pleural effusions→reduced lung volumes
Cardiovascular:
•Pericardial effusions→cardiac tamponade,reduced cardiac output
•Granulomatous disease→ cardiac conduction defects
•Myocarditis→left ventricular failure, reduced cardiac output
•Peripheral vasculitis/Raynaud’ phenomenon→difficulty reading peripheral oxygen saturations
Haematological:
•Anaemia of chronic disease→ patient blood management
•Iron deficiency anaemia due to non-steroidal anti-inflammatory use→pre-operative iron therapy
•Renal: Renal amyloidosis→renal impairment, reduced drug clearance Neurological:
•Autonomic neuropathy→ impairedreflexresponsetointraoperativehypotension •Peripheral neuropathy→care withpositioning,riskof perioperative nerve injury
•Kerato-conjunctivitis→risk of corneal abrasions–care when taping eyelids closed
Skin:
•Thin skin/ easy bruising due to steroid treatment→positioning difficulty
e) List two biological disease-modifying drugs used in the treatment of rheumatoid arthritis. (2 marks)
• Etanercept
• Infliximab
• Adalimumab
• Anakinra
Binds tumour necrosis factor (TNF) Anti-TNF antibody Anti-TNF antibody Blocks activity of iinterleukin-1
Question 9. Ben, a 30-year-old intravenous drug user, is listed for an incision and drainage of a groin abscess. He is known to have human immunodeficiency virus (HIV). Whilst siting the cannula, you suffer a needlestick injury. a) State the risk of developing hepatitis B, hepatitis C and HIV following exposure to infected blood via a needlestick injury. (3 marks)
1in 3 for hepatitis B (33%)
The high risk of hepatitis B transmission is why all health care workers are inoculated against hepatitis B.
1 in 30 for hepatitis C (3.3%)
1 in 300 for HIV (0.33%)
The most recent UK guidelines recommend using a combination drug following HIV exposure. State the name of this drug, and give either the name or class of the two constituent drugs. (3 marks)
Combination drug: Truvada
According to the most recent UK guidelines.
Constituent drugs:
•Emtricitabine/‘nucleoside reverse transcriptase inhibitor (NRTI)’ class
•Tenofovir/‘nucleotide reverse transcriptase inhibitor (NRTI)’ class
d) Susannah’s calculated Apfel score is 3. What is her percentage risk of developing PONV? (1 mark
60%
PONV risk per Apfel score is :0=10%risk,
1=20% risk,
2=40%risk,
3=60% risk,
4=80%risk
e) Complete the following table regarding five drugs that may be used in the management of PONV. (10 marks)
Ondansetron:
Dose: 4mg
Activity: serotonin 5-HT3 receptor antagonist Timing: induction A new 5-HT3 receptor antagonist,Palonosetron, has noeffect onQTc interval and has alonger duration.
○ Droperidol: Dose:0.625–1.25mg Activity: dopamine D2 receptor antagonist Timing: end of surgery
Dexamethasone: 4–8mg Activity: unknown Timing:induction
Aprepitant: Dose: 40 mg Activity: neurokinin-1 receptor antagonist Timing: pre-induction
**Comments NK-1 receptor antagonists are a promising new class of antiemetics originally developed for chemotherapy.
Aprepitant is not associated with QTc prolongation or sedative effects, but its high cost limits its use.
Metoclopramide: Dose: 25–50 mg
Activity: dopamine D2 receptor antagonist Timing: induction
Question 12. You are asked to anaesthetise Michael, a 14-year-old boy who sustained a pellet injury to his eye an hour ago. The surgeons would like to operate straightaway to save his vision.
a) Complete the labels (i–viii) on the following figure. (4 marks)
ai=cornea
ii=iris
iii=lens
iv=ciliary body
v=fovea
vi=retina
vii=choroid
viii=sclera
b) Outline the pathway of aqueous humour, from its site of production to the site of absorption. (4 marks)
Produced by ciliary body •In posterior chamber
•Drains between iris and anterior lens
•Through pupil into anterior chamber
•Exits eye through trabecular network/canal of Schlemm
