Peri-operative care Flashcards
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
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.
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
1% prilocaine
This is the best local anaesthetic for this. Bupivacaine may cause cardiotoxicity and should be avoided.
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
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.
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
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.
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
Large doses may be used prior to commencing cardiopulmonary bypass
As they are not easily reversed they are unsuitable for this purpose.
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
Hartmans
Hartmans solution is the most electrolyte rich. However, both pentastarch and gelofusine have more macromolecules.
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
Carbohydrate rich beverages and loading drinks can cause ileus therefore should be avoided
Carbohydrate loading is one of the enhanced recovery principles.
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
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.
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
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.
Which of the following intravenous fluid solutions has the greatest chloride content?
Dextrose / saline Normal saline Hartmanns solution Ringers lactate 5% dextrose
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
Methylene blue intravenously
Methylene blue stains the parathyroid glands and can be useful in facilitating their identification.
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
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.
Which of these fluids is not an intravenous colloid?
Gelofusine Dextran 40 Human albumin solution Hydroxyethyl starch Bicarbonate 8.4%
Bicarbonate 8.4%
Bicarbonate is a crystalloid.
