CRQ Paper 4

Question 1

Question 1. Anita, a 30-year-old woman, collapses at work following the onset of a severe headache. On arrival at the Emergency Department, she is confused, and her Glasgow Coma Score is 14 (E4V4M6). A CTbrain scan is performed, which shows intraventricular blood. A diagnosis of subarachnoid haemorrhage is made. a) List the three most common causes of blood in the subarachnoid space. (3 marks)

Answer 1

• Rupture of berry aneurysm 1
**AVM rupture and traumatic subarachnoid account for 10% each, with
aneurysm rupture accounting for 80% of
subarachnoid haemorrhage.
• Rupture of arterio-venous
malformation (AVM)
• Traumatic subarachnoid
haemorrhage (SAH)

Question 2

b) List four risk factors associated with the development of aneurysmal subarachnoid haemorrhage. (4 marks

Answer 2

• Genetic
• Associated conditions, e.g.
polycystic kidneys
• Smoking
• Cocaine use
• Amphetamine use
• Ehlers–Danlos type IV
Any 4 Familial risk is significant
if a first-degree relative
has SAH.

Question 3

Complete the labels (i–vi) on the following figure. (3 marks)

Answer 3

i = Anterior cerebral artery
ii = Anterior communicating artery
iii = Middle cerebral artery
iv = Posterior cerebral artery
v = Basilar artery
vi = Posterior communicating artery

Question 4

At which three arteries are berry aneurysms most likely to occur? (3 marks)

Answer 4

• Anterior communicating artery
• Middle cerebral artery
• Posterior communicating artery
** Berry aneurysms occur at
bifurcations of major
arteries.

Question 5

State two early and two late neurological complications of subarachnoid haemorrhage. (4 marks)

Answer 5

Early: Any 2
• Re-bleeding Aneurysms are coiled or clipped within the first few days to prevent re-bleeding.
**The highest risk period is 7–10 days following bleed.
• Seizure
• Hydrocephalus
Late: Any 2
• Delayed cerebral ischaemia/
vasospasm
**Nimodipine is taken for 21 days to reduce risk.
• Cognitive impairment
• Neurocognitive symptoms such
as fatigue, mood disturbance
• Hypopituitarism
**Neuropsychiatric symptoms are common
following SAH.

Question 6

Question 2. Steven is a 2-day-old boy who has presented to the Emergency Department following a sudden collapse. He was born by normal vaginal delivery at 37 weeks without complication. a) A common cause of sudden collapse in a neonate is congenital heart disease.
State two other common causes. (2 marks)

Answer 6

• Sepsis
• Hypoglycaemia
• Metabolic/endocrine disorder
• Trauma/non-accidental injury
Any 2 The differential diagnosis of
collapse in a neonate is
broad.
This is a critical time
for the circulation: ductus
rteriosus closure may
unmask congenital heart
disease

Question 7

b) List four clinical signs that are supportive of a diagnosis of congenital heart disease. (4 marks

Answer 7

• Tachypnoea and sweating whilst
feeding
• Persistent tachycardia
• Hepatomegaly
• Oedema of face/forearm/back/
legs
• Radio-femoral delay
• Cyanosis, especially on crying
• Pathological murmur

**A history of feeding difficulty is common.
Breathing and feeding cannot happen
simultaneously, so cyanotic episodes are often
precipitated by feeding.
NB features of the history are not
clinical signs

Question 8

Steven’s mother describes a history of irritability and cyanotic spells when feeding and crying. Following examination, you suspect a diagnosis of tetralogy of Fallot. c) List the tetrad of features seen in this condition. (4 marks)

Answer 8

• Right ventricular outflow tract obstruction/pulmonary valve stenosis
• Ventricular septal defect (VSD)
• Right ventricular hypertrophy
• Overriding aorta

Question 9

d) List two conditions associated with tetralogy of Fallot. (2 marks)

Answer 9

• DiGeorge syndrome
• 22q11 chromosome deletion
syndrome
• Down’s syndrome
• Cleft lip/palate
• Hypospadias

Question 10

e) Other than feeding, list two other precipitants of a cyanotic episode (tet spell). (2 marks)

Answer 10

• Tachycardia
• Hypotension
• Defaecation
• Crying

Question 11

f) Describe the physiological changes in cardiac blood flow that arise during a t⁸et spell. (4 marks)

Answer 11

• Tet spell is usually precipitated by
an acute decrease in systemic
vascular resistance (SVR)
• Or an acute increase in
pulmonary vascular
resistance (PVR)
• → Increased right-to-left shunt
across VSD
• → Decreased PaO2/increased
PaCO2, decreased pH
• → Tachypnoea
• → Increased negative
intrathoracic pressure
• → Increased venous return
• → Increased right-to-left shunt
across VSD
• → Vicious cycle

Question 12

g) List twoways of managing thesecyanotic episodes in the period leading up to corrective surgery. (2 marks

Answer 12

• Administer oxygen
**The objective is to increase SVR, correct hypoxia and correct acidaemia.
Oxygen administration decreases PVR.
• Console child in knee–chest
position
** This is the equivalent ofthe older TOF child’s
squatting – increasing SVR.
• Opioids/ketamine/midazolam
** Relieves stress and hypercapnoea, but may decrease SVR.
• Correct any underlying cause,
e.g. arrhythmia, hypothermia,
hypoglycaemia

Question 13

Question 3. You are asked to review Sangeeta in the Emergency Department, a 19-year-old woman with a history of insulin-dependent diabetes. She was found collapsed at home and was previously seen 48 hours ago. Her capillary blood glucose is 21.4 mmol/L. a) In the space below, list the criteria (in mmol/L) required for a diagnosis of diabetic ketoacidosis (DKA). (3 marks)

Answer 13

• Blood glucose > 11 mmol/L
(accept > 13.9 mmol/L)
** As per the Joint British Societies Group.
• Ketonaemia > 3.0 mmol/L
** (The American Diabetes Association has slightly different guidance.)
• Bicarbonate < 15.0 mmol/L
(accept < 18.0 mmol/L)
** A pH < 7.30 can be used inplace of bicarbonate in the diagnostic criteria.

Question 14

List the pathophysiological changes that occur as a consequence of insulin deficiency which explain the biochemical findings of hyperglycaemia, ketonaemia, acidosis and glycosuria. (4 marks

Answer 14

Hyperglycaemia:
• Lack of insulin-facilitated
glucose uptake to muscles
• Increase in antagonistic
hormones (glucagon, cortisol,
growth hormone)
• Enhanced hepatic
gluconeogenesis and glycogenolysis

Ketonaemia:
• Enhanced lipolysis increases free
fatty acids
• Fatty acids undergo β-oxidation
into ketoacids

Acidosis:
• Ketoacids dissociate, releasing
hydrogen ions
• High anion gap metabolic
acidosis

Glycosuria:
• Plasma glucose concentration
exceeds capacity of proximal
convoluted tubule to completely
reabsorb glucose from filtrate

Question 15

The results of her arterial blood gas are as follows: pH 7.17
PCO2 4.0 kPa PO2 12.1 kPa HCO3‾ <5 mmol/L Base excess −19.2 mEq/L K+ 7.8 mmol/L 40 Na+ 129 mmol/L
c) Based on the arterial blood gas results above, what would be your immediate management? (1 mark)

Answer 15

• 10 mL of 10% calcium gluconate
• 10 mL of 10% calcium chloride
(accept 10–20 mL)
Immediate management
also includes 50 mL of 50%
dextrose together with 10
units of soluble insulin.

Question 16

d) List the ECG changes that may be seen with hyperkalaemia. (5 marks)

Answer 16

• Peaked T waves
• Prolonged PR segment
• Loss of P-wave
• Prolonged QRS complex
• ST-segment elevation
• Ectopic beats and escape rhythm
• Widening of QRS complex
• Sine wave
• Ventricular fibrillation
• Asystole
• Axis deviation
• Bundle branch block
* A vast array of ECG changes may be seen in hyperkalaemia. They are
normally classified as mild
(5.5–6.5 mmol/L), moderate (6.5–7.5 mmol/L), and severe (>7.5 mmol/L),
although classifications
vary.
** Calcium reduces the
excitability of cardiomyocytes, reducing
the risk of fatal arrhythmias.

Question 17

e) List four other serious complications of DKA. (4 marks)

Answer 17

• Hypokalaemia
• Hypoglycaemia
• Renal impairment
• Cerebral oedema
• Pulmonary oedema
• Death
** Insulin administration may
cause hypokalaemia and
hypoglycaemia. Fluid
administration has been
postulated to cause cerebral
and pulmonary oedema

Question 18

f) List the three endogenous ketone bodies. (3 marks)

Answer 18

• 3-β-hydroxybutyrate
• Acetoacetate
• Acetone
** The predominant ketone in
the body is 3-β- hydroxybutyrate, which is
measured in point-of-care testing.

Question 19

Question 4. Diego, a 3-week-old boy born uneventfully at term,is brought by his mother tothe Emergency Department with progressively worsening non-bilious vomiting, usually directly after a feed.
a) On assessment, Diego is severely dehydrated. List four clinical signs consistent with this class of dehydration. (4 marks)

Answer 19

• General condition: abnormally
sleepy/lethargic
• Anterior fontanelle: markedly
sunken/depressed
• Weak rapid pulse
• Rapid respiratory rate
• Urine output: <0.5 ml/kg/h
• Skin turgor: decreased with tenting
• Mucous membranes: very dry
• Eyes: markedly sunken
** Dehydration is classified in
the context of fluid loss as a
percentage of body weight.
Mild = 5%
Moderate = 10%
Severe = 15%
The classification can help
guide fluid resuscitation.

Question 20

Avenous blood gas is taken, giving the following results:
pH 7.61
PCO2 7.2 kPa
PO2 11.0 kPa
Base excess +30.1 mmol/L
Na+ 136 mmol/L
K+ 3.0 mmol/L
Cl‾ 72 mmol/L
b) Interpret the venous blood gas. (1 mark)

Answer 20

Hypokalaemic, hypochloraemic
metabolic alkalosis
(NB must state all three components
for the mark)
1 Whilst PCO2 is raised,
which may represent partial
respiratory compensation,
conclusions cannot easily
be drawn due to this being a
venous rather than an
arterial blood sample.

Question 21

Onthe basis of the history and blood gas, you suspect a diagnosis of pyloric stenosis. c) List four risk factors for developing pyloric stenosis. (4 marks)

Answer 21

• More common in boys
• Young maternal age
• Maternal family history
• Infants born in autumn and
spring
• Maternal smoking
• Postnatal erythromycin
• Association with bottle feeding
4:1 male:female ratio,
especially common in first-
born boys.

Question 22

d) List two additional features of the clinical examination consistent with a diagnosis of pyloric stenosis. (2 marks)

Answer 22

• Visible peristalsis
** Crossing abdomen from left
to right.
• Olive-like 2–3 cm palpable mass
in right side of epigastrium
**This clinical sign is less
frequently found due to
earlier diagnosis using
ultrasound

Question 23

) List two hormones secreted as a direct response to severe dehydration. (2 marks)

Answer 23

• Antidiuretic hormone (ADH)
** By the hypothalamus/posterior pituitary in response to increased
plasma osmolarity.
• Renin
** Secreted in response to decreased tubular filtrate flow rate or decreased
perfusion of the macula densa

Question 24

Despite the raised plasma pH, Diego’s urine is found to be acidic. f) Which hormone is responsible for this paradox? (1 mark)

Answer 24

Aldosterone
** Acts at principle cells in the
DCT and collecting ducts to absorb water and Na+ in
exchange for K+ and H+. In severe dehydration, the
conservation of water takes precedence over
normalising plasma pH.

Question 25

After 48 hours of intravenous rehydration, Diego’s venous gas has normalised. The surgeons would like to perform a pyloromyotomy. g) List six intra-operative and post-operative considerations specific to this age group and procedure. (6 marks)

Answer 25

• Risk of aspiration on induction, but rapid sequence induction/ cricoid pressure difficult in this age group • Nasogastric or orogastric tube insertion and ‘four quadrant’ aspiration I.e. aspirating the tube with the infant supine, left lateral decubitus, prone and right lateral decubitus. • Use a 3.5 mm cuffed or uncuffed endotracheal tube • Temperature control: increase the theatre ambient temperature to 26°C, use radiant heaters/forced air warmers • Analgesia provided using local anaesthetic techniques and paracetamol • Maintain normoglycaemia in the perioperative period: use of glucose-containing maintenance fluid • Apnoea monitoring in a high-dependency environment Mandatory for infants < 44 weeks post-conceptual age, or for ex-premature infants < 60 weeks post post-conceptual age. • Reduced IV paracetamol dose: 7.5 mg/kg every 6 hours for post-conceptual age 36–44 week

Question 26

Question 5. Siobhan presents to the Emergency Department with a short history of painless vaginal bleeding. She is 38 weeks pregnant and is visiting family in England. She remembers being told about a low-lying placenta but has been unable to attend any follow-up antenatal clinics. a) Describe the four grades of placenta praevia by their relationship to the internal cervical os. (4 marks)

Answer 26

Grade 1: does not abut the internal cervical os/low-lying * Placenta praevia has also been classified as minor or major. Grade 2: reaches margin of internal cervical os/marginal ** Only 10% of those with a low-lying placenta at the20-week scan will go on to have placenta praevia. Grade 3: partially covers internal os/partial Grade 4: completely covers internal cervical os/complete

Question 27

b) Aside from a low-lying placenta, list five risk factors for placenta praevia. (5 marks)

Answer 27

• Previous placenta praevia • Previous termination of pregnancy • Multiparity • Advanced maternal age (>40 years) • Smoking • Deficient endometrium – scarring, endometritis, manual removal of placenta, curettage, fibroid • Assisted conception • Previous caesarean section ** In women who have previously had a caesarean section, 50% of those with a low-lying placenta at 20 weeks’ gestation will go on to have placenta praevia.

Question 28

Following ultrasonography, Siobhan is told that her placenta is anterior and in a position that rules out normal vaginal delivery. Her observations are normal and her symptoms have now subsided. A decision is made to perform a caesarean section. c) How may your anaesthetic differforthis procedure when compared to that of a low-risk elective caesarean section? (7 marks)

Answer 28

• Senior input – consultant anaesthetist • Additional monitoring – arterial line • Additional large bore intravenous access • Regional anaesthesia (must qualify association with reduced blood loss) ** Women with a placental edge < 2cm from the internal os are likely to be delivered by caesarean section. If uncomplicated, this is usually after 38 weeks’ gestation. • Consider general anaesthesia, or consent for rapid conversion • Cell salvage • Cross-match • Rapid infusor • Tranexamic acid • Consent for blood transfusion In women with a history of caesarean section and an anterior low-lying placenta, the risk of placenta accreta should be considered.

Question 29

Abnormal placental adherence describes the degree to which there is an invasion of chorionic villi into the myometrium because of a defect in the decidua basalis. d) List the three forms of abnormal placental adherence (3 marks) in order of increasing incidence. (1 mark)

Answer 29

Least common: placenta percreta 1 Intermediate: placenta increta 1 Most common: placenta accreta 1 Correct order of increasing incidence 1

Question 30

Question 6. Karen, a 65-year-old woman, is referred to pain clinic by her general practitioner. She has a 3-month history of pain on one side of her face in an area affected by a recent episode of shingles. a) Namethe virus that causes shingles. (1 mark)

Answer 30

Varicella zoster virus (VZV) (accept human herpes virus type III) 1 Following a primary infection with VZV (chickenpox), the virus lies dormant in spinal and cranial nerve ganglia.

Question 31

b) List the two most common sites for the shingles rash. (2 marks)

Answer 31

• Thoracic dermatome 1 • Ophthalmic division of trigeminal nerve (ophthalmic division must be specified)

Question 32

c) List three comorbidities which put patients at greater risk of developing shingles.(3marks)

Answer 32

• Diseases affecting the immune system, e.g. lymphoma, human immunodeficiency virus (HIV) Cell-mediated immunity normally prevents reactivation, but inhibition of the immune system may allow reactivation of VZV, causing the characteristic rash of shingles. • Pharmacological immunosuppression: e.g. following organ transplant, autoimmune disease • Treatment of malignancy: chemotherapy, radiotherapy

Question 33

d) List four risk factors for the development of post-herpetic neuralgia (PHN). (4 marks)

Answer 33

• Age > 60 years • Female • More intense initial pain • More severe rash • Prodrome of dermatomal pain before development of rash • Fever (>38°C)

Question 34

e) List six clinical features of PHN. (6 marks)

Answer 34

• Prodromal pain in a single dermatome before onset of rash Pain: • Continuous or intermittent • Throbbing or burning • Allodynia – unable to wear clothing over the involved region Other neurological: • Sensory loss • Motor weakness • Autonomic disturbance – abnormal skin temperature/ colour, abnormal sweating Psychological symptoms: • Isolation • Depression/anxiety • Chronic fatigue • Sleep disturbance Systemic symptoms: • Weight loss

Question 35

f) Regarding the pharmacological management, state a drug used to prevent PHN. (1 mark)

Answer 35

• VZV vaccine booster • Antiviral drugs: acyclovir, valaciclovir, famciclovir Any 1 Antiviral drugs shorten the period of viral replication, and halve the incidence of PHN at 6 months.

Question 36

g) List three first-line treatment options following the onset of PHN. (3 marks)

Answer 36

• Simple analgesics: paracetamol ± codeine • Gabapentinoids: gabapentin, pregabalin • Tricyclic antidepressants • Topical agents: lignocaine and capsacin • Weak opioids: tramadol

Question 37

Question 7. Kevin, a 32-year-old man, is listed for excision of a parathyroid adenoma under general anaesthesia. The parathyroid adenoma was discovered following a series of investigations to identify the cause of Kevin’s hypercalcaemia. a) List six clinical features of hypercalcaemia. (6 marks)

Answer 37

The classical description of ‘stones, bones, abdominal groans and psychic moans’ is rarely seen, with the majority of patients having few symptoms on diagnosis. • Bone pain • Muscle weakness, reduced reflexes • Fatigue Gastrointestinal: • Constipation • Anorexia • Nausea and vomiting Renal: • Polyuria resulting in dehydration • Renal stones The mechanism of polyuria is nephrogenic diabetes insipidus secondary to nephrocalcinosis. Neuropsychiatric: • Depression/anxiety • Cognitive dysfunction: confusion, psychosis • Insomnia Depression is common, up to 40% of patients are affected.

Question 38

b) Where are the parathyroid glands normally located? (2 marks)

Answer 38

• Two pairs of parathyroid glands 1 There is considerable variability in the number of glands and their location. The parathyroid glands may even descend into the thorax with the thymus. • Embedded in the superior and inferior poles of the thyroid gland bilaterally

Question 39

c) Whichinvestigation is used to locate the parathyroid adenoma pre-operatively? (1 mark)

Answer 39

Technetium-99 m-sestamibi scintigraphy

Question 40

d) List four physiological effects of excess secretion of parathyroid hormone (PTH). (4 marks)

Answer 40

Kidney: • Increased Ca2+ resorption in the loop of Henle, distal convoluted tubule and collecting duct • Increased phosphate (PO43–) excretion in the proximal convoluted tubule • Increased production of 1,25-dihydroxycholecalciferol (vitamin D3) PTH increases the activity of 1-α-hydroxylase enzyme, which converts 25-hydroxycholecalciferol to vitamin D3. Bone: • Increased bone resorption to release Ca2+ • Inhibits osteoblast activity, stimulates osteoclasts activity Intestine: • Ca2+ is reabsorbed indirectly **The PTH-induced increase in vitamin D is responsible for this effect

Question 41

The patient’s serum Ca2+ concentration on the day of surgery is 2.9 mmol/L. Your unit’s policy is that surgery should proceed if the serum Ca2+ is below 3.0 mmol/L. e) List two perioperative considerations in patients with moderate hypercalcaemia. (2 marks)

Answer 41

• Lower doses of anaesthetic agents may be needed if somnolent • Hypercalcaemia may augment neuromuscular blockade: reduce doses of muscle relaxants and use neuromuscular monitoring The risk of intra-operative cardiac arrhythmias is much greater for patients with Ca2+ > 3.0 mmol/L. • Increased incidence of cardiac arrhythmias

Question 42

f) Following surgery, the patient becomes markedly hypocalcaemic. List four clinical features of acute hypocalcaemia. (4 marks)

Answer 42

• Peri-oral/digital parasthesias • Positive Trousseau’s sign ** Trousseau’s sign is inducing carpal spasm by inflating a blood pressure cuff. • Positive Chvostek’s sign ** Chvostek’s sign is facial spasm induced by tapping the inferior zygoma. • Carpopedal spasm • Laryngospasm • ECG changes: prolonged QT interval and torsades de pointes • Negative chronotropy/inotropy Mnemonic for severe hypocalcaemia: CATS go numb = convulsions, arrythmias, tetany, laryngospasm, go numb = paraesthesias.

Question 43

Thepatient has a family history of hyperparathyroidism. Name an inherited endocrine condition which includes hyperparathyroidism. (1 mark)

Answer 43

g • Multiple endocrine neoplasia (MEN) type 1 and 2A Any 1 The multiple endocrine neoplasias are syndromes characterised by tumours of several endocrine glands. ** MEN 1 is characterised by the ‘3Ps’ – pituitary, parathyroid and pancreatic ** MEN 2A by ‘2Ps and 1 M’: phaeochromocytoma, parathyroid, medullary thyroid. • Familial isolated hyperparathyroidism

Question 44

Question 8. You are asked to review Geraint, a 69-year-old man, in the Emergency Department. He has been vomiting violently throughout the night and has developed central chest pain. The general surgical registrar is concerned that he has Boerhaave syndrome (transmural oesophageal perforation). a) List four clinical signs specific to a diagnosis of oesophageal perforation. (4 marks)

Answer 44

• Chest/neck surgical emphysema • Resonant percussion ** Due to pneumothorax. • Dull percussion Due to atelectasis or consolidation. • Reduced air entry on auscultation **Due to atelectasis or consolidation. • Hamman crunch **Cracking sound of pneumomediastinum on auscultation.

Question 45

b) List four signs consistent with oesophageal perforation that may be seen on a CT scan. (4 marks

Answer 45

• Peri-oesophageal air • Pneumomediastinum • Pneumopericardium • Cervical surgical emphysema • Pneumothorax • Pleural effusion (usually left sided) • Lung abscess • Pneumoperitoneum Any 4 Which tissues are contaminated by air/gastric contents depends on the location of the oesophageal perforation. Boerhaave syndrome most commonly affects the mid-thoracic oesophagus, whilst trauma secondary to oesophagoscopy most commonly results in perforation at the cricopharyngeus, and just proximal to the lower oesophageal sphincter.

Question 46

A diagnosis of oesophageal perforation is made and an open oesophageal repair via a thoracotomy is planned. c) State two considerations that may affect your drug choices during induction of anaesthesia. (2 marks)

Answer 46

• Sepsis is likely with potential for haemodynamic instability –consider use of cardiostable induction agent, e.g. ketamine • Rapid sequence induction is indicated, but suxamethonium Increases intragastic pressure – use rocuronium The use of cricoid pressure (which may increase the risk of exacerbating mediastinal contamination through coughing/straining) must be balanced against the risk of soiling lungs.

Question 47

d) List the two options for airway management in this case. (2 marks

Answer 47

• Double-lumen endotracheal tube (DLETT) 1 Left sided DLETT is usually preferred, as right-sided DLETT risks occlusion of the right upper lobe bronchus. • Single lumen endotracheal tube with bronchial blocker 1 An endotracheal tube of at least 7.5 mm is required.

Question 48

e) List two strategies that you would take to prevent lung injury during the case. (2 marks)

Answer 48

• Low tidal volume: 6–8 mL/kg during two lung ventilation, 5–6 mL/kg whilst on one-lung ventilation Any 2 • Permissive hypercapnoea • Avoid fluid overload Fluid guided by pulse contour analysis cardiac output monitor – clearly this is not the time to use an oesophageal Doppler!

Question 49

The procedure is difficult, and intra-operatively, the patient spends 8 hours in the lateral position. f) List six complications of prolonged lateral positioning in this case. (6 marks)

Answer 49

• Displacement of double-lumen endotracheal tube ** A fibre-optic scope should be immediately available, and the DLETT position checked following any patient repositioning. • V̇ /Q̇ mismatch and shunt, leading to hypoxaemia • Radial nerve palsy in superior arm **The radial nerve is particularly at risk if the arm is abducted > 90°; an axillary roll is used to prevent mid-humeral radial nerve compression. • Common perineal nerve palsy in the inferior leg ** Due to compression between the fibular head and the operating table. • Saphenous nerve palsy of either leg ** A pillow is usually placed between the knees to prevent this complication. • Brachial plexus injury ** The neck must be in a neutral position to prevent brachial plexus stretch. • Ear injury **Ensure that the ear has not folded during positioning. • Optic neuropathy ** The lower globe is at risk from external compression from the pillow in the lateral position. • Pressure injury to bony prominences, e.g. iliac cres

Question 50

Question 9. Sarah, a 42-year-old woman, is listed for a laparoscopic cholecystectomy. Her body mass index (BMI) is calculated as 45 kg/m2. a) In which category of obesity would she be placed? (1 mark)

Answer 50

• Obesity class III ** According to the WHO classification of obesity 2014. This BMI would previously have been classified as morbidly obese.

Question 51

At pre-operative assessment, the patient completes a STOP-BANG questionnaire which suggests she is at high risk of obstructive sleep apnoea (OSA). b) Other than obesity, list four risk factors for the development of OSA in all patient groups. (4 marks)

Answer 51

• Craniofacial abnormalities (such as Pierre–Robin and Down’s syndromes, acromegaly) • Tonsillar and adenoidal hypertrophy = the major cause of OSA in children. • Male gender ** Male gender: possibly as a result of a relatively increased amount of fat deposition around the pharynx. • Age 40–70 years • Enlarged neck circumference >37 cm women, >43 cm men. • Neuromuscular disease

Question 52

c) List three health conditions that may result as a consequence of OSA. (3 marks)

Answer 52

• Neuropsychiatric: depression, anxiety **OSA patients experience many neuropsychiatric symptoms such as daytime somnolence, impaired concentration, irritability. These are not considered ‘health conditions’. • Endocrinological: diabetes mellitus, dyslipidaemia, infertility, hypothyroidism • Cardiovascular: hypertension, myocardial infarction, stroke, atrial fibrillation, pulmonary hypertension

Question 53

d) List four options that you would recommend to this patient for the management of her OSA. (4 marks

Answer 53

• Weight loss • Reduce/stop alcohol intake • Smoking cessation • Nasal continuous positive airway pressure (nCPAP) ** Overnight nCPAP set at between +5 and +20 cmH2O probably works by acting as a pneumatic splint to maintain upper airway patency. It has the effect of reducing daytime sleepiness, improving mood and cognitive function, and improving blood pressure control. • Sleep modification (i.e. sleeping in lateral position or 30° head up instead of supine)

Question 54

The patient is established on OSA treatment and presents for a laparoscopic cholecystectomy. e) List four physiological consequences of a raised intra-abdominal pressure as a result of pneumoperitoneum. (4 marks

Answer 54

• Increased systemic vascular resistance this is thought to be due to mechanical compression of the aorta, release of vasoactive substances –vasopressin, catecholamines, and activation of the renin-angiotensin-aldosterone system. • Decreased preload due to compression of the inferior vena cava • Diaphragmatic splinting/reduced functional residual capacity ** Results in atelectasis and V̇ /Q̇ mismatch • Raised intrathoracic pressure/reduced pulmonary compliance • Decreased liver/renal/splanchnic arterial and venous blood flow ** Glomerular filtration rate decreases by ~25%; gut mucosal blood flow decreases by ~40%. • Decreased cerebral venous drainage, which leads to raised intracranial pressure ** This is of particular relevance for prolonged surgical procedures performed in a steep Trendelenburg position, which may result in cerebral oedema. • Activation of the sympathetic nervous system ± parasympathetic nervous system

Question 55

f) List four complications of the surgical positioning used when performing a laparoscopic cholecystectomy in this patient. (4 marks

Answer 55

• Manual handling of the patient ** Greater number of members of staff required for lateral transfer, plus special equipment (e.g. hover mattress). • Width of operating table Side extensions are often required for bariatric patients. • Patient movement on operating table once positioned in reverse Trendelenburg, Bariatric patients are often positioned prior to induction of anaesthesia in a seated position with a support under bent knees to limit movement. • Reduced venous return in reverse Trendelenburg position ** In combination with pneumoperitoneum may result in hypotension. • Peripheral nerve injury **This is a complication of surgical positioning in any patient, but particularly in the left arm following left lateral tilt.

Question 56

Question 10. Matt, a 24-year-old man, is listed for a bimaxillary (combination of maxillary and mandibular) osteotomy. a) List six perioperative airway concerns specific to bimaxillary osteotomy. (6 marks)

Answer 56

• Shared airway • Nasal intubation required **The mouth must be free to enable the occlusion of the teeth to be checked intra-operatively. • Nasal intubation risks epistaxis ** Due to direct trauma to Kisselbach’s plexus of Little’s area. • Intra-operative damage to nasal endotracheal tube ** The site of surgery is inclose proximity to the nasal tube. • Bimaxillary surgery may be performed in patients with comorbidities associated with difficult laryngoscopy E.g. previous cleft palate repair, obstructive sleep apnoea. • Possibility of patient being woken with rigid inter-maxillary fixation (IMF) IMF is ‘wiring’ the teeth together – more commonly, elastic bands are applied after the patient has left PACU. • Intra-operative throat pack commonly used • Intra-operative head movement may result in extubation or endobronchial intubation • Post-operative bleeding/haematoma **Post-operative bleeding may rapidly result in airway obstruction, particularly in patients with rigid IMF.

Question 57

) On examination, you notice that Matt has obstructed nasal passages. List three alternative methods of airway management for this case. (3 marks

Answer 57

• Retromolar reinforced oral endotracheal tube **An oral flexible endotracheal tube is pushed behind the molar teeth, so that the teeth can still be occluded. • Submental intubation ** The end of a conventional endotracheal tube (minus its connector) is passed through the floor of the mouth. • Tracheostomy

Question 58

c) List four techniques for minimising intra-operative blood loss during a bimaxillary osteotomy. (4 marks)

Answer 58

Position the patient head up • Induced hypotension • Surgical infiltration with adrenaline-containing local anaesthetic • Tranexamic acid ** The bony mid-face receives an extensive blood supply, and the posterior maxilla is close to the pterygoid venous plexus.

Question 59

d) List three advantages for using total intravenous anaesthesia (propofol and remifentanil) for this case ( osteotomy). (3 marks

Answer 59

• Reduced incidence of post-operative nausea and vomiting (PONV) **PONV is common in bimaxillary osteotomy surgery, and may be dangerous if jaws are wired post-operatively. • Used to induce intra-operative hypotension, improving operative field • Smooth extubation without coughing or straining **Coughing and straining may promote bleeding

Question 60

e) List four precautions that you would take to reduce the risk of a retained throat pack. (4 marks

Answer 60

• Label or mark the patient’s head with an adherent sticker • Label the endotracheal tube or laryngeal mask airway • Attach the pack to the artificial airway • Leave part of the pack protruding • Include in the swab count • Not using a throat pack Any 4 Retained throat pack is a ‘never event’. The National Patient Safety Agency issued a Safer Practice Notice with these recommendations in 2009.

Question 61

Question 11. Pete, a 22-year-old man with epilepsy and severe learning difficulties, is listed for a magnetic resonance (MR) scan of his brain under general anaesthesia. a) Pete’s parents ask you to provide premedication to avoid unnecessary distress during IV cannulation. List four pharmacological options. (4 marks)

Answer 61

• Topical Eutectic Mixture of Local **Anaesthetics (EMLA)/Ametop, If accepted by the patient! • Midazolam Oral/buccal (10–20 mg) has an unpleasant taste that can be masked with squash/juice; intranasal (0.2 mg/kg) stings. • Temazepam Dose 10–30 mg, tablets may not be acceptable to the patient. • Ketamine Side effects: increased salivation, dissociative state. ** Routes of administration are oral 5–10 mg/kg, intranasal 3–5 mg/kg, intramuscular 4 mg/kg. • Clonidine Oral dose 4 μg/kg

Question 62

b) Outline the physical principles of magnetic resonance imaging. (4 marks)

Answer 62

• Hydrogen atoms are abundant within the body within water molecules • Hydrogen atoms possess a property called ‘spin’ • When surrounded by a strong magnet, spin aligns with the magnetic field • Spin can be turned out of alignment with the magnetic field by applying pulses of electromagnetic radiation • The energy emitted is detected by three receiving coils, and translated into a series of grey pixels on a screen * The three coils are positioned to generate a three-dimensional image.

Question 63

c) TheMRscanner uses a superconducting magnet. What is superconductivity (2 marks), and how is it achieved (1 mark)?

Answer 63

Superconductivity: • A phenomenon where electrical resistance in a coil of wire decreases to zero below a critical temperature • Passing of an electric current through a coil of wire results in a strong magnetic field (electromagnet) **A typical MR scanner uses a magnetic field strength of 1.5 Tesla. Achieved by: • Cooled to 4.2 K by surrounding the coils in liquid helium * This is usually surrounded by a jacket of liquid nitrogen, which has a boiling point of 77 K, to keep the expensive liquid helium from boiling away.

Question 64

The patient is sedated and the radiographers go through their safety checklist with his parents. d) List four implanted ferromagnetic objects that may cause harm to the patient if subjected to the strong static magnet. (4 marks)

Answer 64

• Cardiac pacemaker/loop recorder • Aneurysm clip • Cochlear implant • Shrapnel/penetrating eye injury involving metal • Cardiac defibrillator • Any type of nerve/neuro stimulator • Joint replacement • Hydrocephalus shunt

Question 65

The patient is now anaesthetised and ready to enter the MR scanning room. A laryngeal mask airway (LMA) was chosen for airway management. e) Which part of the LMA risks degradation of the MR image? (1 mark)

Answer 65

The pilot balloon **The pilot balloon contains a ferromagnetic spring whichis normally secured by tape, away from the area to be scanned.

Question 66

f) Asidefromtheinteraction between ferromagnetic objects and the strong static magnetic f ield, list four additional classes of hazards specific to the MR environment. (4 marks)

Answer 66

• Time-varying magnetic gradient fields ** Small dynamic magnetic fields can induce a current sufficient to stimulate peripheral nerve and muscle cells, causing discomfort. • Acoustic noise ** Switching of gradient fields creates loud acoustic noise, above the safe level of 85 dB – patients and staff need ear protection. • Radiofrequency heating **Power dissipation within the patient, causing an increase in body temperature. There is a risk of severe, rapid burns from any conductive material left on the patient’s skin: ECG leads, metal in clothing etc. • Helium escape ** In the event of a spontaneous or emergency field shutdown (a ‘quench’), the liquid helium (and nitrogen) expands to a gas and must be vented very rapidly, with the potential for a hypoxic environment within the MRI scan room.

Question 67

Question 12. You are asked to assess Ash, a 32-year-old man who has been admitted to the Emergency Department after being trapped in a house fire. He has burns across his chest, abdomen and left arm. His estimated weight is 100 kg. a) List five clinical features that would lead you to suspect a significant inhalational injury. (5 marks)

Answer 67

• Singed hairs of eyebrows/ eyelashes/nasal hair • Swelling of the face, lips, tongue or uvula • Soot in nose/mouth/sputum • Inspiratory stridor • Change in voice/hoarseness • Dyspnoea • Coughing • Wheezing • Copious secretions

Question 68

b) Whatare the distinguishing features of the following degrees of burn injury? (3 marks)

Answer 68

○ First-degree burn: red, painful, dry, no blisters ** Only epidermis involved. ○ Second-degree burn: red, blistered, painful, oedematous ** Epidermis and dermis involved. ○ Third-degree burn: white, painless, no bleeding on pricking with a needle ○ Full thickness burn causing destruction of all skin layers plus underlying tissues.

Question 69

c) The ED registrar states that the patient has burns covering an estimated 30% body surface area (BSA). How has she come to this conclusion? (2 marks)

Answer 69

• Wallace ‘Rule of nines’ (accept: Lund-Browder chart) • Chest/abdomen represents 18% BSA; one arm represents 9% BSA *The adult head represents 9% BSA, whereas a child has a proportionally bigger head (representing 18% BSA) and smaller legs (representing 13.5% BSA each)

Question 70

The ED nurse asks you to prescribe fluid for the patient. It has now been 1 hour since the patient was burnt. d) What formula will you use to calculate this patient’s intravenous resuscitation fluid? (2 marks) What will you prescribe? (2 marks)

Answer 70

Parkland formula: ** The Parkland formula is the most widely used in the UK. It does not incorporate maintenance fluid which should be considered in addition to the resuscitation fluid. • Fluid requirement 4 mL × weight kg × % burn • Half of the fluid given within the first 8 hours, the other half over the next 16 hours. Prescription: 4 mL × 100 kg × 30% = 12,000 mL ⇒ Prescription: 6000 mL Hartmann’s over 7 hours, then 6000 mL Hartmann’s over 16 hours

Question 71

e) TheEDregistrar discusses the case with the regional burns centre. List three indications for transfer to a specialist burns centre. (3 marks)

Answer 71

• Age: < 5 years or > 60 years old • Site of burn: hands, feet,bperineum, any flexure (e.g. neck, axilla), circumferential burn of limb, torso or neck. • Inhalational injury • Mechanism of burn: chemical, steam, ionising radiation • > 10% BSA burn (adult) or > 5% BSA burn (child) • Significant comorbidities • Significant associated injuries, e.g. head injury, crush injur

Question 72

Although the patient’s airway is currently patent, you remain concerned about an inhalational injury. You decide to intubate the patient prior to transfer to the regional burns centre. f) List three management considerations specific to inhalational burn injury. (3 marks)

Answer 72

• Rapid sequence induction • Uncut endotracheal tube • Tape the endotracheal tube in place rather than use a tie • Minimum of size 8.0 mm endotracheal tube to facilitate bronchoscopy • Insert a nasogastric tube at the same time ** If inhalational injury is suspected, early intubation is crucial. The specialist burns centre will be happy to receive an intubated patient who they can extubate the following day if there are concerns about the airway. ** Suxamethonium is not contraindicated until 48 hours after the burn.

Question 73

Ap

Answer 73

• Apnoea monitoring in a high-dependency environment Mandatory for infants < 44 weeks post-conceptual age, or for ex-premature infants < 60 weeks post post- conceptual age. • Reduced IV paracetamol dose: 7.5 mg/kg every 6 hours for post- conceptual age 36–44 week

Question 74

e) List the three most common scoring systems in the United Kingdom for grading the severity of aneurysmal subarachnoid haemorrhage. (3 marks

Answer 74

Hunt andHess grading scale for subarachnoid haemorrhage (clinical) WFNS=World Federation of Neurological Surgeons •WFNS Gradingc Scale for Aneurysmal Subarachnoid Haemorrhage(clinical) •Fisher grade (based on CT scan) **There are many more scoring systems, but these three are byfar thecmost commonly used.