Peri-operative care

Question 1

Of the agents listed below, which is the most appropriate to give a 65 year old man with a locally unresectable gastrointestinal stromal tumour. Biopsies confirm that it is KIT positive.

Imatinib
Infliximab
Trastuzumab
Bevacizumab
Cetuximab

Answer 1

Imatinib

Imatinib is licensed for treatment of GIST in the United Kingdom for this situation. The guidance from the National Institute of Clinical evidence is that patients be reviewed at 12 weeks after initiating therapy.

Question 2

A 72 year old woman fractured her distal radius. A Biers Block is planned to facilitate reduction of the fracture. Which of the following agents should be used?

1% lignocaine
1% lignocaine with 0.5% bupivacaine mixed in 50:50 mixture
1% prilocaine
1% lignocaine with 1 in 200,000 adrenaline
1% prilocaine with 1 in 200,000 adrenaline

Answer 2

1% prilocaine

This is the best local anaesthetic for this. Bupivacaine may cause cardiotoxicity and should be avoided.

Question 3

A 32 year old man requires venous access for chemotherapy for acute myeloid leukaemia. What is the best option?

Groshong line
Internal jugular central line (triple lumen)
14 G cannula in the dorsum of the hand
18 G cannula in the non dominant hand
Sub cuticular catheter

Answer 3

Groshong line

Groshong lines and Hickman lines are similar and knowledge of these systems is needed because surgeons are often called upon to either insert or remove them. Chemotherapy for AML requires long term therapy and multiple blood tests therefore an indwelling device is preferable.

Question 4

A 66 year old man is admitted with severe angina. There is a lesion of the proximal left anterior descending coronary artery. Which of the following would be the most suitable conduit for bypass?

Long saphenous vein
Short saphenous vein
Cephalic vein
Internal mammary artery
Thoraco-acromial artery

Answer 4

Internal mammary artery

The internal mammary artery is an excellent conduit for coronary artery bypass. It has better long term patency rates than venous grafts. The thoraco-acromial artery is seldom used.

Question 5

Which of the following statements relating to low molecular weight heparins is false?

They act via inhibition of Factor Xa
Large doses may be used prior to commencing cardiopulmonary bypass
They have a highly predictable pharmacokinetic profile
They are derivatives of unfractionated heparin
They have a molecular mass in the range of 3000-10000Da

Answer 5

Large doses may be used prior to commencing cardiopulmonary bypass

As they are not easily reversed they are unsuitable for this purpose.

Question 6

A 45 year old man is undergoing a small bowel resection. The anaesthetist decides to administer an intravenous fluid which is electrolyte rich. Which of the following most closely matches this requirement?

Dextrose / Saline
Pentastarch
Gelofusine
Hartmans
5% Dextrose with added potassium 20mmol/ L

Answer 6

Hartmans

Hartmans solution is the most electrolyte rich. However, both pentastarch and gelofusine have more macromolecules.

Question 7

Which of the following statements relating to pre-operative fluid management is false?

5% dextrose should be given cautiously in the elderly
Patients undergoing elective colonic resections may continue to drink water up to 2 hours prior to surgery
Normal saline increases the risk of hyperchloraemic acidosis
A 70kg man will need approximately 100mmol of sodium daily
Carbohydrate rich beverages and loading drinks can cause ileus therefore should be avoided

Answer 7

Carbohydrate rich beverages and loading drinks can cause ileus therefore should be avoided

Carbohydrate loading is one of the enhanced recovery principles.

Question 8

Which of the following would be the optimal fluid management option for a 45 year old man due to undergo an elective right hemicolectomy?

Remain ‘nil by mouth’ for at least 6 hours pre-operatively and avoid intra venous fluids

Remain ‘nil by mouth’ for at least 6 hours pre-operatively and receive supplementary intravenous 5% dextrose to replace lost calories

Allow him free access to oral fluids only until 30 minutes prior to surgery

Administer a carbohydrate based loading drink 3 hours pre operatively, and avoid intravenous fluids

Administer a carbohydrate based loading drink 6 hours pre-operatively and administer 5% dextrose saline thereafter

Answer 8

Administer a carbohydrate based loading drink 3 hours pre operatively, and avoid intravenous fluids

Patients for elective surgery should not have solids for 6 hours pre-operatively. However, clear fluids may be given up to 2 hours pre-operatively. Enhanced recovery programmes are now the standard of care in many countries around the world and involve administration of carbohydrate loading drinks.
The routine administration of 5% dextrose in the scenarios given above would convey little in the way of benefit and increase the risks of electrolyte derangement post operatively.

Question 9

A 52 year old male presents with central chest pain and vomiting. He has drunk a bottle of vodka. On examination, there is some mild crepitus in the epigastric region. What is the likely diagnosis?

Pulmonary embolus
Perforated peptic ulcer
Oesophageal perforation
Myocardial infarct
Pneumothorax

Answer 9

Oesophageal perforation

The Mackler triad for Boerhaave syndrome: vomiting, thoracic pain, subcutaneous emphysema. It typically presents in middle aged men with a background of alcohol abuse.

Question 10

Which of the following intravenous fluid solutions has the greatest chloride content?

Dextrose / saline
Normal saline
Hartmanns solution
Ringers lactate
5% dextrose

Answer 10

Normal saline

Normal saline has the highest chloride content and excessive administration of normal saline is a recognised risk factor for the development of hyperchloraemic metabolic acidosis.

Question 11

A 5 year old boy undergoes a closure of a loop colostomy. What thromboprophylaxis should be used?

None
Daily low dose low molecular weight heparin for 2 weeks
Daily low dose low molecular weight heparin until discharged
Unfractionated heparin and compression stockings
Oral dabigatran for 4 weeks

Answer 11

None

In paediatric surgical practice, the use of heparin type agents is rare. This is because, even with abdominal surgery, children are ambulant soon after surgery and DVT’s vanishingly rare in this population.

Question 12

A 30 year old male is admitted electively for a right inguinal hernia repair under local anaesthesia. He is otherwise well but his grandfather died from a pulmonary embolism. What is the most appropriate form of thromboprophylaxis?

Administration of low dose low molecular weight heparin for 2 weeks

Administration of high dose low molecular weight heparin for 2 weeks

No prophylaxis

Low dose low molecular weight heparin and pneumatic compression stockings

High dose low molecular weight heparin and pneumatic compression stockings

Answer 12

No prophylaxis

Inguinal hernia repairs under local anaesthetic have a short operative time and patients are usually ambulant immediately afterwards. His family history is unlikely to be significant and he is at very low risk.

Question 13

A 52 year old male presents with central chest pain. On examination, he has an mitral regurgitation murmur. An ECG shows ST elevation in leads V1 to V6. There is no ST elevation in leads II, III and aVF. What is the diagnosis?

Pulmonary embolism
Boerhaaves syndrome
Inferior myocardial infarct
Prinzmetal angina
Anterior myocardial infarct

Answer 13

Anterior myocardial infarct

The most likely diagnosis is an anterior MI. As there are no ST changes in the inferior leads, aortic dissection is less likely.

Question 14

A 52 year old male presents with tearing central chest pain. On examination, he has an aortic regurgitation murmur. An ECG shows ST elevation in leads II, III and aVF. What is the likely explanation?

Distal aortic dissection
Anterior myocardial infarct
Inferior myocardial infarct
Proximal aortic dissection
Pulmonary embolism

Answer 14

Proximal aortic dissection

An inferior myocardial infarction and AR murmur should raise suspicions of an ascending aorta dissection rather than an inferior myocardial infarction alone. Also the history is more suggestive of a dissection. Other features may include pericardial effusion, carotid dissection and absent subclavian pulse.

Question 15

A 24 year old man is due to undergo an excision of a sebaceous cyst of his scalp which of the agents below should be used for local anaesthesia?

1% lignocaine with 1 in 200,000 adrenaline
1% lignocaine alone
1% prilocaine
0.5% bupivicaine
0.25% bupivacaine with 1 in 200,000 adrenaline

Answer 15

1% lignocaine with 1 in 200,000 adrenaline

Scalp wounds often bleed and the addition of adrenaline is therefore desirable. Lignocaine is fast acting and the preferred agent.

Question 16

A 48 year old lady is being prepared for a Whipples procedure. A right sided subclavian line is inserted and then anaesthesia is induced. Following intubation the patient becomes progressively hypoxic and haemodynamically unstable. What is the most likely underlying explanation?

Drug allergy
Simple pneumothorax
Tension pneumothorax
Halothane toxicity
Haemothorax

Answer 16

Tension pneumothorax

Central lines (and particularly subclavian lines) are risk factors for the development of pneumothorax. In the context of positive pressure ventilation a tension pneumothorax is a strong possibility and would be associated with haemodynamic instability.

Question 17

Which of the following is not typically associated with a degloving injury?

Overlying pallor of the skin
Abnormal motility of the overlying skin
History of friction type injury
Improved results when the degloved segment is left in situ as a temporary closure
Poor results when primary compression treatment is used in preference to skin grafting

Answer 17

Improved results when the degloved segment is left in situ as a temporary closure

Degloving injuries typically involve extremities and are usually friction injuries e.g. arm being run over. There is abnormal motility of the overlying skin, pallor, loss of sensation. Early treatment is key and should involve skin grafting which may use the degloved segment. This however, should be formally prepared for the role and simple compression bandaging gives poor results.

Question 18

The following are contra indications to the use of lignocaine for local anaesthesia except:

Accelerated idioventricular rhythm
Current treatment with flecainide
3rd degree heart block without pacemaker
Severe sino atrial block
Protein C deficiency

Answer 18

Protein C deficiency

Lignocaine is widely used as a local anaesthetic. As a class IB antiarrhythmic it should not be used in people with unstable disorders of cardiac rhythm and ideally should not be co-administered with other anti-arhythmics.

Question 19

A 45 year old man with previous laparotomy is admitted with adhesional small bowel obstruction. He is managed with prolonged nasogastric drainage. His U+E’s are as follows:

Sodium 129
Potassium 3.4
Urea 8.4
Creatinine 89

Which of the following intravenous fluids should be prescribed?

0.4%/0.18% dextrose saline
0.9% Sodium Chloride
0.9% sodium chloride with 40mmol potassium chloride per litre
Hartmanns solution
5% dextrose with 20mmol KCl

Answer 19

0.9% sodium chloride with 40mmol potassium chloride per litre

The potassium will decline further if this deficiency is not addressed. Remember that potassium is predominantly an intracellular cation. U+E’s measure the serum potassium which is relatively buffered by the intra cellular stores. Therefore a fall in serum potassium represents a very real intracellular deficiency. This requires supplementary potassium to correct the defect.

Question 20

Which of the following preparatory regimes should be considered for a 63 year old man with normal renal function who requires a diagnostic colonoscopy to investigate iron deficiency anaemia for which he takes ferrous sulphate?

Stop ferrous sulphate 7 days pre procedure and administration of oral purgatives the day prior to the procedure

Administration of oral purgatives the day prior to the procedure and continue ferrous sulphate

Continue ferrous sulphate and administration of phosphate enemas on the day

Cease ferrous sulphate 7 days pre procedure and administration of phosphate enema 30 minutes pre procedure

No preparation required

Answer 20

Stop ferrous sulphate 7 days pre procedure and administration of oral purgatives the day prior to the procedure

Endoscopy requires full bowel preparation. In elderly patients, this can cause electrolyte disturbance and renal compromise and it is important to check the patients urea and electrolytes beforehand. Drugs like ferrous sulphate impair the efficacy of purgatives and give poor endoscopic views as a result and should be stopped beforehand.

Question 21

A 3 year old is involved in trauma and is haemodynamically unstable. Initial attempts at intravenous access are proving unsuccessful. What is the best course of action?

Insert a femoral venous central line

Insert a right internal jugular central line

Insert an intra osseous infusion system

Insert a 14 G cannula into the antecubital fossa

Insert a Broviac line

Answer 21

Insert an intra osseous infusion system

Gaining venous access in small children is challenging at the best of times and when they are shut down its nearly impossible. Intraosseous infusions are best in this setting. Broviac lines are long term IV access systems with narrow lumens and would be unsuitable.

Question 22

Administration of which of the following may facilitate the identification of parathyroid glands intra operatively?

Patent V dye intravenously
Methylene blue intravenously
Indigocarmine dye intravenously
India ink intravenously
Intravenous rifampicin

Answer 22

Methylene blue intravenously

Methylene blue stains the parathyroid glands and can be useful in facilitating their identification.

Question 23

A 23 year old man is reviewed on the ward 10 days following a laparotomy. The wound is inspected and is healing well. Which of the following processes is least likely to be occurring in the wound at this stage?

Angiogenesis
Synthesis of collagen
Necrosis of fibroblasts
Secretion of matrix metalloproteinases by fibroblasts
Proliferation of fibroblasts

Answer 23

Necrosis of fibroblasts

Fibroblasts are an important cell type in healing wounds. They typically proliferate in the early phases of wound healing. They release matrix metalloproteinases and these facilitate in the remodelling of the matrix within the healing wound. Necrosis in a healing wound would be unusual as wounds will tend to show clinical evidence of angiognesis by this time.

Question 24

Which of these fluids is not an intravenous colloid?

Gelofusine
Dextran 40
Human albumin solution
Hydroxyethyl starch
Bicarbonate 8.4%

Answer 24

Bicarbonate 8.4%

Bicarbonate is a crystalloid.

Question 25

Which of the following local anaesthetics is not an amino amide type? ``` Lignocaine Xylocaine Procaine Bupivacaine Prilocaine ```

Answer 25

Procaine

Question 26

A 73 year old man presents with a tumour at the central aspect of the posterior third of the tongue. To which of the following lymph node groups is it most likely to metastasise? ``` Submental Submandibular Ipsilateral deep cervical nodes Contralateral deep cervical nodes Bilateral deep cervical nodes ```

Answer 26

Bilateral deep cervical nodes Posterior third tumours of the tongue commonly metastasise to the bilateral deep cervical lymph nodes Tumours of the posterior third of the tongue will typically metastasise early and bilateral nodal involvement is well recognised, this is most often true of centrally located tumours and those adjacent to the midline as the lymph vessels may cross the median plane at this location.

Question 27

A 78 year old man develops sudden onset abdominal pain and almost immediately afterwards passes a large amount of diarrhoea. What is the most appropriate investigation? ``` Abdominal x-ray CT angiogram Abdominal MRI scan Abdominal USS Rigid sigmoidoscopy ```

Answer 27

CT angiogram Sudden onset of abdominal pain followed by forceful evacuation are the classical presenting features of acute mesenteric infarction. This is best investigated by CT angiography, which has a sensitivity of 95% for the diagnosis.

Question 28

A 23 year old man has a routine ECG performed. Which part of the tracing obtained represents atrial repolarisation? ``` P wave T wave Q-T Interval P-R interval None of the above ```

Answer 28

None of the above The process of atrial repolarisation is generally not visible on the ECG strip. It occurs during the QRS complex.

Question 29

A 10 year old boy is shot in the abdomen with an airgun pellet. He is concerned that he will get into trouble and the injury remains concealed for 10 days. Imaging using CT scanning shows it to be lodged in the left lobe of the liver. On examination, his abdomen is soft and non tender and he seems well. What is the best course of action? Operate and remove the pellet on the next emergency list Operate and remove the pellet on the next elective operating list Do not operate and review the patient several weeks later Extract the pellet using interventional radiology techniques Perform an MRI scan

Answer 29

Do not operate and review the patient several weeks later Given that the child is well, the risks of removing the pellet are not outweighed by the benefits and it should be left in situ at this stage.

Question 30

Which of the following blood products can be administered to a non ABO matched recipient? ``` Whole blood Platelets Packed red cells Stem cells Irradiated whole blood ```

Answer 30

Platelets In the UK, platelets either come from pooling of the platelet component from four units of whole donated blood, called random donor platelets, or by plasmapharesis from a single donor. The platelets are suspended in 200-300 ml of plasma and may be stored for up to 4 days in the transfusion laboratory where they are continually agitated at 22oC to preserve function. One adult platelet pool raises the normal platelet count by 30,000 to 60,000 platelets litre. ABO identical or compatible platelets are preferred but not necessary in adults; but rhesus compatibility is required in recipients who are children and women of childbearing age to prevent haemolytic disease of the newborn.

Question 31

A 48 year old lady has a metallic heart valve and requires a paraumbilical hernia repair. Perioperatively she is receiving intra venous unfractionated heparin. To perform the surgery safely a normal coagulation state is required. Which of the following strategies is routine standard practice? Administration of 10 mg of vitamin K the night prior to surgery and stopping the heparin infusion 6 hours pre operatively Stopping the heparin infusion 6 hours pre operatively Stop the heparin infusion on induction of anaesthesia Stopping the heparin infusion 6 hours pre operatively and administration of intravenous protamine sulphate on commencing the operation None of the above

Answer 31

Stop the heparin infusion on induction of anaesthesia atients with metallic heart valves will generally stop unfractionated heparin 6 hours pre operatively. Unfractionated heparin is generally cleared from the circulation within 2 hours so this will allow plenty of time and is the method of choice in the elective setting. Protamine sulphate will reverse heparin but is associated with risks of anaphylaxis and is thus not generally used unless immediate reversal of anticoagulation is needed, e.g. coming off bypass.

Question 32

A surgeon is considering using lignocaine as local anasthesia for a minor procedure. Which of the following best accounts for its actions? Blockade of neuronal acetylcholine receptors Blockade of neuronal nicotinic receptors Blockade of neuronal sodium channels Blockade of neuronal potassium channels Blockade of neuronal calcium channels

Answer 32

Blockade of neuronal sodium channels Lignocaine blocks sodium channels. They will typically be activated first, hence the pain some patients experience on administration.

Question 33

A 63 year old man is recovering following an open extended right hemicolectomy for carcinoma of the colonic splenic flexure. Two days post operatively he develops a persistent pyrexia. What is the least likely cause? ``` Ileus Aspiration pneumonia Anastomotic leak Wound infection Urinary tract infection ```

Answer 33

Ileus An ileus in itself is seldom a cause of a pyrexia. It may serve as a proxy marker of other complications. In this scenario atelectasis would be the most likely underlying cause, as open extended right hemicolectomies will necessitate a long midline incision. Anastomotic leaks are less common after right sided colonic surgery and the timeframe for it is rather short (but are possible). Both wound infections and UTI's ,may complicate major abdominal surgery at any stage. We remind you to check the wording of the question, it asks for the 'least likely' cause of pyrexia.

Question 34

Which of the following statements related to coronary artery bypass surgery is true? Late graft stenosis is mainly associated with saphenous vein grafts Is indicated if there is stenosis > 70% of the right coronary artery The left atrium is cannulated during the procedure The CHADS score is used to assess peri operative risk Cardioplegia is always undertaken at a 37 degrees

Answer 34

Late graft stenosis is mainly associated with saphenous vein grafts Indications are: 1. Left main stem stenosis or equivalent (proximal LAD and proximal circumflex) 2. Triple vessel disease 3. Diffuse disease unsuitable for PCI The right atrium is cannulated. The CHADS score assesses whether a patient should be warfarinised if they have atrial fibrillation. Cardioplegia can be undertaken at cold or warm temperatures.

Question 35

Which of the following is associated with poor wound healing? ``` Jaundice Patients taking carbamazepine General anaesthesia using thiopentone General anaesthesia using ketamine Multiple sclerosis ```

Answer 35

Jaundice Mnemonic to remember factors affecting wound healing: DID NOT HEAL D iabetes I nfection, irradiation D rugs eg steroids, chemotherapy ``` N utritional deficiencies (vitamin A, C & zinc, manganese), Neoplasia O bject (foreign material) T issue necrosis ``` H ypoxia E xcess tension on wound A nother wound L ow temperature, Liver jaundice Multiple sclerosis is associated with pressure sores, however the cellular healing process is not affected.

Question 36

If a 2 x 2 cm autologus skin graft is placed on an area of healthy granulation tissue. After about a week, a thin bluish - white margin appears around the graft and spreads at a rate of 1mm per day. What is it? ``` Epidermis alone Epidermis and dermis Dermis alone Inflammatory exudate Fibrin ```

Answer 36

Epidermis alone | This is the process of re-epithelialisation.

Question 37

Which of the following changes are not typically seen in established dehydration? ``` Rising haematocrit Urinary sodium <20mmol/ litre Metabolic acidosis Decreased serum urea to creatinine ratio Hypernatraemia ```

Answer 37

Decreased serum urea to creatinine ratio ``` Diagnosing dehydration can be complicated, laboratory features include: Hypernatraemia Rising haematocrit Metabolic acidosis Rising lactate Increased serum urea to creatinine ratio Urinary sodium <20 mmol/litre Urine osmolality approaching 1200mosmol/kg ```

Question 38

A 57 year old man is coming off the cardiac bypass circuit following a successful coronary artery bypass procedure. Which drug should be administered to normalise the patients clotting prior to decannulation and chest closure? ``` Intravenous vitamin K Protamine sulphate Aprotinin Fresh frozen plasma None of the above ```

Answer 38

Protamine sulphate Since cardiac bypass circuits are thrombogenic large doses of intravenous heparin are administered. This is reversed with protamine sulphate. FFP may be effective but would carry a significant risk of fluid overload.

Question 39

An 83 year old man is admitted for an abdomino-perineal excision of the colon and rectum for a distal rectal tumour. His co-morbidities include diabetes. His renal function is normal. What is the best form of thromboprophylaxis? None Compression stockings alone for 4 weeks Daily low dose low molecular weight heparin for 4 weeks Daily high dose low molecular weight heparin for 4 weeks Daily administration of high dose unfractionated heparin until discharge

Answer 39

Daily low dose low molecular weight heparin for 4 weeks There is good evidence to support the use of extended thromboprophylaxis after pelvic cancer surgery. Don't confuse low dose and high dose low molecular weight heparins, re read the options if you got the answer wrong.

Question 40

A patient receives atropine as pre medication prior to a laparotomy. Which of the following is least likely to occur? ``` Pupillary dilation Dry mouth Urinary retention Bradycardia Decreased salivation ```

Answer 40

Bradycardia Since it inhibits vagal tone, the use of atropine will typically result in an increased heart rate. Atropine is a muscarinic receptor antagonist (competitive antagonist for the muscarinic acetylcholine receptor). It therefore inhibits parasympathetic activity.It was traditionally used as a premedication for anaesthesia because it reduced bronchial secretions, salivary secretions and bradycardia from increased vagal tone on anaesthetic induction. Modern anaesthetic techniques have reduced the need for routine use of this drug. Its other effects include urinary retention and pupillary dilatation.

Question 41

Which of the following statements relating to use of tourniquets in surgery is false? The use of an esmarch bandage tourniquet to exsanguinate the limb reduces the incidence of neuropraxia. Excessive inflation pressures are amongst the commonest causes of nerve injury related to tourniquet use. Tourniquet deflation causes a fall in CVP. Children require lower inflation pressures than adults. In patients developing neuropraxia related to tourniquets the radial nerve is most frequently affected.

Answer 41

The use of an esmarch bandage tourniquet to exsanguinate the limb reduces the incidence of neuropraxia. The use of esmarch bandage tourniquet increases the risk of nerve injury as it increases pressure in the limb. Limb elevation is safer.

Question 42

A 19 year old man has a skin lesion excised from his back. He is reviewed clinically at 4 months post procedure and the surgeon notes that the scar has begun to contract. Which of the following facilitates this process? ``` Myofibroblasts Neutrophils Granuloma formation Macrophages Fibroblasts ```

Answer 42

Myofibroblasts As wounds mature the fibroblast population differentiates into myofibroblasts (usually 6 weeks and beyond), these have a contractile phenotype and therefore help in contracting the wound. Immature fibroblasts, though able to adhere to the ECM, do not have this ability.

Question 43

A 53 year old alcoholic male presents with acute pancreatitis. He is clinically dehydrated. His blood results show normal renal function and electrolytes. Which of the intravenous fluids below should be prescribed? ``` 0.9% sodium chloride and 40mmol KCl 5% dextrose Hartmanns solution 10% dextrose and 20mmol KCl 5% dextrose and 40 mmol KCl ```

Answer 43

Hartmanns solution This patient needs fluid replacement due to large third space losses. Hartmann's solution is recommended. N. Saline would put this patient at risk of hyperchloraemic acidosis.

Question 44

A 62 year old lawyer has a transurethral resection of the prostate which took 1 hour to perform. The ST2 contacts you as the patient has become agitated. He has a HR 105 bpm and his blood pressure is 170/100 mmHg. He is fluid overloaded. His blood results reveal a Na of 120mmol/l. What is the most likely cause? Over administration of 0.9% Normal Saline Syndrome of inappropriate antidiuretic hormone secretion Congestive cardiac failure TURP syndrome Acute renal failure

Answer 44

TURP syndrome Complications of Transurethral Resection: TURP T ur syndrome U rethral stricture/UTI R etrograde ejaculation P erforation of the prostate TUR syndrome occurs when irrigation fluid enters the systemic circulation. The triad of features are: 1. Hyponatraemia: dilutional 2. Fluid overload 3. Glycine toxicity Management involves fluid restriction and the treatment of the complications associated with the hyponatraemia.

Question 45

A 53 year old man is due to undergo a right hemicolectomy for a caecal carcinoma. Which of the following would be usual practice prior to surgery? Oral carbohydrate loading drink 2 hours pre operatively Mechanical bowel preparation with oral sodium picosulphate Mechanical bowel preparation with oral mannitol Total gut cleansing with oral antibiotics 3 days pre-operatively Iodine rectal washout pre-operatively

Answer 45

Oral carbohydrate loading drink 2 hours pre operatively Of the options presented here, only the oral carbohydrate drink would be standard practice prior to a right sided colonic resection. Whilst some surgeons may administer phosphate enemas before surgery, total gut clearance confers no benefit for right sided resections and delays recovery. In contrast, the carbohydrate loading drink is part of enhanced recovery protocols.

Question 46

Which of the following statements relating to Keloid scars is untrue? They have a predilection for sternal , mandibular and deltoid area wounds They are confined to the margins of the original injury They often recur following excision May occur even after superficial injury They may be treated by injection of triamcinolone

Answer 46

They are confined to the margins of the original injury Hypertrophic scars remain confined to the wound edges. Keloids (by definition) will tend to extend beyond the margins of the wound and in wounds of any depth.

Question 47

A 22 year old man presents with a peri anal abscess, which is managed by incision and drainage. The perineal wound measures 3cm by 3cm. Which of the following is best management option? Primary closure with interrupted mattress sutures Delayed primary closure with interrupted mattress sutures Allow the wound to heal by secondary intention Insert a seton through the cavity into the rectum to allow a mature fistula track to develop Perform a V-Y flap 2 weeks later

Answer 47

Allow the wound to heal by secondary intention Peri anal abscess are typically managed by secondary intention healing. Any attempt at early closure is at best futile and at worst dangerous. Insertion of a seton may be considered by an experienced colorectal surgeon, and only if the tract is clearly identifiable with minimal probing. There is seldom a need for flaps, ongoing discharge usually indicates a fistula (managed separately).

Question 48

A 67 year old patient is due to undergo a femoro-popliteal bypass graft. Which heparin regime should the surgeon ask for prior to cross clamping the femoral artery? Single therapeutic dose of low molecular weight heparin on the ward prior to coming to theatre Single therapeutic dose of low molecular weight heparin the night before surgery Dose of 10,000 units of unfractionated heparin prior to induction of anaesthesia Dose of 3,000 units of unfractionated heparin, 3 minutes prior to cross clamping Dose of 30,000 units of unfractionated heparin, 3 minutes prior to cross clamping

Answer 48

Dose of 3,000 units of unfractionated heparin, 3 minutes prior to cross clamping As a rule most vascular surgeons will administer approximately 3,000 units of systemic heparin 3-5 minutes prior to cross clamping to help prevent further intra arterial thromboses. A dose of 30,000 units is given prior to going on cardiopulmonary bypass. Heparin given at induction will cause bleeding during routine dissection.

Question 49

Which of the following associations are incorrect? Afro-Caribbean ethnicity and keloid scarring Extensive third degree burns and wound contraction Chemotherapy and dehiscence of healed wounds Poor healing at the site of previous radiotherapy Zinc deficiency and delayed healing

Answer 49

Chemotherapy and dehiscence of healed wounds

Question 50

A 6 year old child requires long term drug therapy to treat a rare genetic disorder. The drug must be given intravenously. Recently, there have been issues with the child pulling at the current system of the Hickman line and the parents are requesting an alternative. What is the best option? Triple lumen subclavian line Portacath device Intermittent cannulation as needed PICC line Broviac line

Answer 50

Portacath device Portacaths are a good choice for children as they only need to be accessed when they are used. Broviacs would pose the same core problems as a Hickman.

Question 51

Which statement relating to the peri operative management of patients with diabetes mellitus is false? They should be placed first on the operating list An intravenous sliding scale should be used in all cases Potassium supplementation is likely to be required in diabetics on a sliding scale Electrolyte abnormalities are more common after major visceral resections Blood glucose monitoring is required during general anaesthesia

Answer 51

An intravenous sliding scale should be used in all cases This is not the case and some type 2 diabetics may be managed using a watch and wait policy with regular blood glucose monitoring. The cellular shifts of potassium with sliding scales may cause problems with electrolyte management which should be anticipated.

Question 52

A 20 year old African lady undergoes an open appendicectomy. She is reviewed for an unrelated problem 8 months later. On abdominal inspection the wound site is covered by shiny dark protuberant scar tissue that projects beyond the limits of the skin incision. Which of the following is the most likely underlying process? ``` Hypertrophic scar Keloid scar Marjolins ulcer Repeated episodes of wound sepsis Mycosis fungoides ```

Answer 52

Keloid scar Keloid scars extend beyond the limits of the incision. Mycosis fungoides is a cutaneous T cell lymphoma.

Question 53

Which of the agents listed below is most likely to help a 22 year old lady with severe peri anal Crohns disease and multiple anal fistulae? The acute sepsis has been drained and setons are in place. She is already receiving standard non biological therapy. ``` Trastuzumab Bevacizumab Imatinib Cetuximab Infliximab ```

Answer 53

Infliximab Infliximab is a popular choice in managing complex peri anal Crohns. It is absolutely vital that all sepsis is drained prior to starting therapy.

Question 54

In relation to patients with type 1 diabetes mellitus undergoing surgery, which of the following statements is untrue? They should not receive oral carbohydrate loading drinks as part of enhanced recovery programmes When a variable rate insulin infusion is required 0.45% sodium chloride and 5% dextrose with either 0.15% or 0.3% potassium are the fluids of choice Hourly intraoperative blood glucose measurements are required Insulin infusions are only required in patients who will miss more than two meals or who are nil by mouth for greater than 12 hours Blood glucose levels persistently greater than 12 should initiate a change in therapy

Answer 54

Insulin infusions are only required in patients who will miss more than two meals or who are nil by mouth for greater than 12 hours Insulin should not be stopped in patients with type 1 diabetes and omission of more than one meal will usually require a variable rate insulin infusion Type 1 diabetics who take insulin should have this continued through the perioperative period. Fluid guidelines in diabetics differ and are not well covered in NPSA fluid guidelines.

Question 55

An 80 year old lady is investigated in the pre operative clinic and found to have severe aortic stenosis. What, if any, is the main peri operative concern? ``` They cannot adjust their heart rate They may have ventricular hypertrophy The patient cannot increase their cardiac output They are more prone to arrhythmias There is no concern ```

Answer 55

The patient cannot increase their cardiac output Patients with aortic stenosis are a major perioperative concern. They may have ventricular hypertrophy and this can result in relative myocardial ischaemia and increase the risk of arrhymias. However, the main concern is that they cannot increase their cardiac output particularly if vasodilation occurs.

Question 56

A surgeon is considering using lignocaine to provide local anaesthesia for a minor surgical procedure. Which of the following may attenuate its action? ``` Hyperkalaemia Administration with adrenaline Administration with bupivicaine Administration with sodium bicarbonate Use in tissues which are infected ```

Answer 56

Use in tissues which are infected Local anaesthetics are relatively ineffective when used in infected tissues. Most anaesthetic agents are amine bases that become ionised due to the relative alkalinity of tissues. In active infection there may acidosis of the tissues and therefore local anasthetics may be less effective. Some surgeons mix sodium bicarbonate as it is reported to reduce the pain experienced by patients during administration.

Question 57

A 55 year old man requires a flexible sigmoidoscopy to investigate bright red rectal bleeding. What is the most appropriate preparation? Single phosphate enema the day prior to the procedure Single phosphate enema 30 minutes pre procedure Oral sodium picosulphate the day prior to the procedure Oral sodium picosulphate 30 minutes prior to the procedure Rectal lavage with saline 1 hour pre procedure

Answer 57

Single phosphate enema 30 minutes pre procedure For a limited endoscopy a simple enema will suffice.

Question 58

Which of the following local anaesthetic preparations would be most suitable for an 18 year old male undergoing a unilateral Zadeks procedure? Ring block with 0.5% bupivacaine with 1 in 200,000 adrenaline Application of topical amethocaine Ring block with 1% lignocaine alone Ring block with 1% lignocaine and 1 in 200, 000 adrenaline Ring block with 0.25% bupivacaine with 1 in 80,000 adrenaline

Answer 58

Ring block with 1% lignocaine alone Local anaesthetics: avoid use of adrenaline in extremities This is excision of the toe nail and a fast acting local anaesthetic is indicated. Adrenaline should be avoided in this setting as it can cause digital ischaemia.

Question 59

In relation to operating in the elderly which statement is false? A 30 minute increment in operation length is associated with increase in mortality in patients over the age of 80 Hypoalbuminaemia is associated with increased mortality Statins given preoperatively reduce perioperative cardiac events Elevated brain (or B-type) natriuretic peptide (BNP) levels before undergoing non cardiac surgery is associated with high risk of cardiac mortality and all cause mortality Beta blockers should be stopped acutely prior to surgery due to risk of perioperative hypotension

Answer 59

Beta blockers should be stopped acutely prior to surgery due to risk of perioperative hypotension Beta blockers should not be stopped acutely prior to surgery as there may be a rebound effect associated with increased complications. Brain natriuretic peptide is a neurohormone synthesized in the cardiac ventricles. Levels have been used to assess prognosis in heart failure and acute coronary syndromes. Preoperative elevated brain natriuretic peptide levels identify patients undergoing non cardiac surgery at high risk of cardiac mortality and all cause mortality. All patients with peripheral vascular disease should take statins prior to vascular surgery as studies have shown a 50% risk reduction and a reduction in perioperative cardiac events. Proactive care of older people undergoing surgery (POPS) Comprehensive geriatric assessment MDT assessment preoperatively Main predictors of complications are co-morbidities cardiac disease and reduced functional capacity - preoperative assessment is the key to preventing adverse postoperative outcomes Patients screened for risk factors (albumin <30, co morbidities) Management plan made and disseminated to all involved Patients education: pain relief, post op exercises, nutrition Outcomes: Fewer postoperative medical complications Reduced length of stay by 4.5 days

Question 60

A 43 year old lady with a metallic heart valve has just undergone an elective paraumbilical hernia repair. In view of her metallic valve, she is given unfractionated heparin perioperatively. How should the therapeutic efficacy be monitored, assuming her renal function is normal? ``` Therapeutic monitoring is not required Measurement of APTT Measurement of INR Measurement of Prothromin time None of the above ```

Answer 60

Measurement of APTT Unlike low molecular weight heparins that do not require monitoring unfractionated heparin does require monitoring, this is done by measuring the APTT.

Question 61

A 32 year old lady has previously undergone a wide local excision and axillary node clearance (5 nodes positive) for an invasive ductal carcinoma. It is oestrogen receptor negative, HER 2 positive, vascular invasion is present. She has a lesion suspicious for metastatic disease in the left lobe of her liver. Of the agents listed below, which is the most likely to be beneficial in this setting? ``` Cetuximab Bevacizumab Trastuzumab Basiliximab Imatinib ```

Answer 61

Trastuzumab This lady's young age, coupled with ER negativity and extensive nodal disease with suspicion of metastatic disease makes her a candidate for treatment with trastuzumab (herceptin).