15- Post operative MSQs Only

Question 1

1 of 67

Which statement is false about pethidine?

Answer 1

It is thirty times more lipid soluble than morphine
Structurally similar to morphine(Right)
Pethidine has a toxic metabolite (norpethidine) which is cleared by the kidney
Pethidine is metabolized by the liver
Can be given intramuscularly
…………………………………………………
It has a different structure. It is much more lipid soluble than morphine. It produces less biliary tract spasm than morphine.

Question 2

2 of 67

Which statement regarding post operative cognitive impairment is true?

Answer 2

Use of Benzodiazepines preoperatively reduces long-term post operative cognitive dysfunction(Right)

Pain does not cause delirium

Delirium has no impact on length of hospital stay

A regional anaesthetic rather than a general anaesthetic is more likely to contribute to post operative cognitive impairment

Visual hallucinations are not a feature of delirium
…………………………………………………………………………
Anaesthetic technique and Post operative cognitive impairment (POCD):
Use of benzodiazepines preoperatively reduces long-term POCD (9.9% vs. 5%)
Do not stop drugs for cognitive function
Regional techniques reduce POCD in first week, but no difference at 3 months

Question 3

3 of 67

A 17 year old man undergoes an elective right hemicolectomy. Post operatively he receives a total of 6 litres of 0.9% sodium chloride solution, over 24 hours. Which of the following complications may ensue?

Answer 3

Hyperchloraemic acidosis

Excessive infusions of any intravenous fluid carry the risk of development of tissue oedema and potentially cardiac failure. Excessive administration of sodium chloride is a recognised cause of hyperchloraemic acidosis and therefore Hartmans solution may be preferred where large volumes of fluid are to be administered.

Question 4

4 of 67

Which of the arterial blood gas analyses would most likely be seen in a patient with a high output ureterosigmoidostomy?

Answer 4

pH 7.25, pO 8.9, pCO 3.2, HCO 10

There is acidosis. To compensate the patient will attempt to raise the pH level in the blood by hyperventilating, hence the low CO2 level

Question 5

5 of 67

A 28 year old man with Crohn’s disease has undergone a number of resections. His BMI is currently 18 and his albumin is 18. He feels well but does have a small localised perforation of his small bowel. The gastroenterologists are giving azathioprine. What is the most appropriate advice regarding feeding?

Answer 5

Parenteral feeding

This man is malnourished, although he is likely to require surgery it is best for him to be nutritionally optimised first. As he may have reduced surface area for absorption and has a localised perforation TPN is likely to be the best feeding modality.

Question 6

5 of 67

A 28 year old man with Crohn’s disease has undergone a number of resections. His BMI is currently 18 and his albumin is 18. He feels well but does have a small localised perforation of his small bowel. The gastroenterologists are giving azathioprine. What is the most appropriate advice regarding feeding?

Answer 6

Parenteral feeding

This man is malnourished, although he is likely to require surgery it is best for him to be nutritionally optimised first. As he may have reduced surface area for absorption and has a localised perforation TPN is likely to be the best feeding modality.

Question 7

6 of 67

Which of the agents listed below can be administered via the peripheral intra venous route in the non cardiac arrest setting?

Answer 7

Metaraminol

Metaraminol is an alpha receptor agonist.
As a general rule, inotropes and vasopressors can only be administered via a central vein. Metaraminol is an exception to this as it can be administered via a peripheral line.

Question 8

9 of 67

A 51 year old man is shot in the abdomen and sustains a significant intra abdominal injury. A laparotomy, bowel resection and end colostomy are performed. An associated vascular injury necessitates a 6 unit blood transfusion. He has a prolonged recovery and is paralysed and ventilated for 2 weeks on intensive care. He receives total parenteral nutrition and is eventually weaned from the ventilator and transferred to the ward. On reviewing his routine blood tests the following results are noted:

Full blood count
Hb 11.3 g/dl
Platelets 267 x 10 /l
WBC 10.1 x10 /l

Urea and electrolytes
Na 131 mmol/l
K 4.6 mmol/l
Urea 2.3 mmol/l
Creatinine 78 μmol/l

Liver function tests
Bilirubin 25 μmol/l
ALP 445 u/l
ALT 89 u/l
γGT 103 u/l

What is the most likely underlying cause for the abnormalities noted?

Answer 8

Total parenteral nutrition

TPN is known to result in derangement of liver function tests. Although, cholestasis may result from TPN, it would be very unusual for gallstones to form and result in the picture above. Blood transfusion reactions typically present earlier and with changes in the haemoglobin and although they may cause hepatitis this is rare nowadays.

Question 9

7 of 67

Which of the following anaesthetic agents is least likely to be associated with depression of myocardial contractility?

Answer 9

Etomidate

Of the agents mentioned, etomidate has the most favorable cardiac safety profile.

Question 10

8 of 67

A 75 year old man is admitted to the intensive care unit following a laparotomy. He has a central line, pulmonary artery catheter and arterial lines inserted. The following results are obtained:
Pulmonary artery occlusion pressure: High
Cardiac output: Low
Systemic vascular resistance: High
How may these findings be best interpreted?

Answer 10

Cardiogenic shock

In cardiogenic shock pulmonary pressures are often high. This is the basis for the use of venodilators in the treatment of pulmonary oedema.

Question 11

11 of 67

Which of the intravenous fluid combinations listed below should be considered for replacement of losses from a high output ileostomy in a 2 year old?

Answer 11

0.9% saline with added potassium

In children with ongoing losses, these should be replaced with 0.9% sodium chloride with added potassium.

Question 12

10 of 67

Which of the following agents is most likely to be helpful in controlling refractory hypotension in a 23 year old female with severe pyelonephritis?

Answer 12

Noradrenaline

Since the main issue here is vasodilation, a vasoconstrictor is most likely to be helpful.

Question 13

12 of 67

Infusion with which of the following blood products is most likely to result in an urticarial reaction?

Answer 13

Fresh frozen plasma

Pyrexia is the most common adverse event in transfusing packed red cells Urticaria is the most common adverse event following infusion of FFP

Question 14

13 of 67

A 63 year old man has been on the intensive care unit for a week with adult respiratory distress syndrome complicating acute pancreatitis. He has required ventilation and is still being mechanically ventilated. What is the best option for maintenance of his airway?

Answer 14

Tracheostomy

Tracheostomy is often used to facilitate long term weaning. The percutaneous devices are popular. These involve a seldinger type insertion of the tube. A second operator inserts a bronchoscope to ensure the device is not advanced through the posterior wall of the trachea. Complications include damage to adjacent structures and bleeding (contra indication in coagulopathy).

Question 15

14 of 67

A 32 year male with leukaemia attends the day unit for a blood transfusion. Five days after the transfusion he attends the Emergency Department with a temperature of 38.5, erythroderma and desquamation. What is the most likely explanation?

Answer 15

Graft versus host disease

This is associated with transfusion of unirradiated blood in immunosuppressed patients. Transfusion associated GVHD can occur 4-30 days after a transfusion and follows a sub acute pathway. Patients may also have diarrhoea and abnormal liver function tests. Management involves steroid therapy.

Question 16

15 of 67

A 45 year old man is admitted to the intensive care unit following a laparotomy. He has a central line, pulmonary artery catheter and arterial lines inserted. The following results are obtained:
Pulmonary artery occlusion pressure: Low
Cardiac output: Low
Systemic vascular resistance: High
What is the most likely interpretation of this?

Answer 16

Hypovolaemia

Cardiac output is lowered in hypovolaemia due to decreased preload.

Question 17

16 of 67

Which of the anaesthetic agents below is most likely to induce adrenal suppression?

Answer 17

Etomidate

Etomidate is a recognised cause of adrenal suppression, this has been associated with increased mortality when used as a sedation agent in the critically ill.

Question 18

17 of 67

A 23 year old man is recovering from an appendicectomy. The operation was complicated by the presence of perforation. He is now recovering on the ward. However, his urine output is falling and he has been vomiting. Which of the following intravenous fluids should be initially administered, pending analysis of his urea and electrolyte levels?

Answer 18

Hartmans solution

He will have sequestration of electrolyte rich fluids in the abdomen and gut lumen. These are best replaced by use of Hartmans solution in the first instance.

Question 19

18 of 67

Which of the variables listed below is not considered in the sequential organ failure assessment (SOFA) tool?

Answer 19

Bilirubin
Urea (Right)
Mean arterial pressure
Platelet count
Creatinine
…………………………………………
Urea is not one of the variables considered.

Question 20

19 of 67

Which of the following muscle relaxants will tend to incite neuromuscular excitability following administration?

Answer 20

Suxamethonium

Suxamethonium may induce generalised muscular contractions following administration. This may raise serum potassium levels.

Question 20

20 of 67

A 4 week old preterm neonate is due to have surgery for an inguinal hernia. Which of the following fluids should be administered whilst they are nil by mouth?

Answer 20

10% dextrose

Neonates are at considerable risk of hypoglycaemia following surgery and should receive 10% dextrose.

Question 21

22 of 67

Which of the agents listed below is a phosphodiesterase inhibitor?

Answer 21

Milrinone

Question 21

21 of 67

A 28 year old lady with known von Willebrands disease is bleeding following the excision of a sebaceous cyst. Administration of which of the following agents is most likely to be beneficial?

Answer 21

Desmopressin

Desmopressin is useful in managing the bleeding from the commonest type of vWD. Vasopressin is less likely to be disease specific and at most would have a vasoconstrictor approach which is likely to be of brief duration.

Question 22

23 of 67

Which of the following conditions is most likely to be associated with these arterial blood gas sample results:
pH 7.48
pO 10.1
HCO 30
pCO 4.5
Cl 96mEq

Answer 22

Metabolic alkalosis

These arterial blood gas results are classically seen in situations where there is metabolic alkalosis such as may occur following prolonged vomiting.

Question 23

25 of 67

A 22 year old fit and well male undergoes an emergency appendicectomy. He is given suxamethonium. An inflamed appendix is removed and the patient is returned to recovery. On arrival in the recovery area; the patient develops a tachycardia of 120 bpm and a temperature of 40 C. He has generalised muscular rigidity. What is the most likely diagnosis?

Answer 23

Malignant hyperthermia

Anaesthetic agents, such as suxamethonium, can cause malignant hyperthermia in patients with a genetic defect. Acute dystonic reaction normally is associated with antipsychotics (haloperidol) and metoclopramide. These lead to marked extrapyramidal effects. Serotonin syndrome is associated with the antidepressants selective serotonin reuptake inhibitors (SSRIs) and selective serotonin/norepinephrine reuptake inhibitors (SSNRIs). This causes a syndrome of agitation, tachycardia, hallucinations and hyper-reflexia.

Question 23

24 of 67

A 45 year old man develops acute respiratory distress syndrome during an attack of severe acute pancreatitis. Which of the following is not a feature of adult respiratory distress syndrome?

Answer 23

It usually consists of type I respiratory failure.
Patients typically require high ventillatory pressures.
A Swann Ganz Catheter would typically have a reading in excess of 18mmHg. (Right)
It may complicate acute pancreatitis.
It may heal with fibrosis.
……………………………………………………
Right heart pressure should be normal.

Question 24

26 of 67

Which of the anaesthetic agents listed below is associated with hepatotoxicity?

Answer 24

Halothane

Halothane is largely of historical interest and that is because of its hepatotoxicity.

Question 25

27 of 67

Use of which of the following muscle relaxants is least likely to result in histamine release?

Answer 25

Suxamethonium

Drugs in the tetrahydroisoquinoline such as atracurium cause histamine release. Vecuronium and suxamethonium do not do this.

Question 26

28 of 67

Which of the following statements relating to the use of human albumin solution is false?

Answer 26

When administered in the peri operative period it does not increase the length of stay in hospital compared with crystalloid solutions.

Concentrated solutions may produce diuresis in patients with liver failure.

It may restore plasma volume in cases of sodium and water overload.

It may be associated with risk of acquiring new variant Creutzfeldt-Jakob disease.

Hepatitis C remains a concern when large volumes are infused.(Right)
…………………………………………………………
Human albumin solution went out of vogue following the Cochrane review in 2004 that showed it increased mortality. This view has been challenged and subsequent studies have confirmed it to be safe for use. Viruses are inactivated during the preparation process. However, theoretical risks regarding new varient CJD still exist. Outcomes in the peri operative setting are similar whether colloid, crystalloid or albumin are used.

Question 27

29 of 67

A 28 year old man with poorly controlled Crohns disease is nutritionally compromised. The decision is made to start TPN, via which of the following routes should it be best administered?

Answer 27

Internal jugular vein via a central venous catheter

Since TPN solutions are irritant to veins they are best administered via a central line. The femoral route has a higher incidence of line associated sepsis and is thus best avoided in this setting.

Question 28

30 of 67

Which of the following is not typically included in total parenteral nutritional solutions?

Answer 28

Fibre (Right)
Lipid
Potassium
Glucose
Magnesium
………………………………………..
There is no indication for inclusion of fibre in solutions of TPN, nor would it be safe to do so.

Question 29

31 of 67

Which of the following does not need monitoring during home parenteral nutritional support?

Answer 29

Folate levels
Zinc levels
Vitamin D
Thyroid function (Right)
Bone densitometry

Question 30

32 of 67

Which statement is true on enteral feeding?

Answer 30

A PEG can only be used 12 hours after insertion
A motility agent is avoided for ITU patients with an Nasogastric tube
A regime of 24 hours continuous feeding is recommended for ITU patients(Right)
It is associated with more hepatic synthetic disruption than use of TPN
Enteral feeding is not possible in upper GI dysfunction

Question 31

33 of 67

Which of the following anaesthetic agents has the strongest analgesic effect?

Answer 31

Ketamine

Ketamine has a moderate to strong analgesic effect. It may be used for emergency procedures outside the hospital environment to induce anaesthesia for procedures such as emergency amputation.

Question 32

35 of 67

A 63 year old man undergoes a subtotal colectomy and iatrogenic injury to both ureters is sustained. He develops renal failure and his serum potassium is found to be elevated at 6.9 mmol/L. An ECG is performed, what is the most likely finding?

Answer 32

Peaked T waves

Peaked T waves are the first and most common finding in hyperkalaemia.

Question 32

34 of 67

A 56 year old man with chronic schizophrenia undergoes a cholecystectomy. He receives metoclopramide for post operative nausea. Twenty minutes later he becomes agitated and develops marked oculogyric crises and oromandibular dystonia. Which of the following drugs may best alleviate his symptoms?

Answer 32

Procyclidine

This man has developed an acute dystonic reaction. Administration of further anti dopaminergic drugs will worsen the situation. Procyclidine will help to reverse the event. This is most likely to have occurred because the patient is on long term anti psychotics and has then received metoclopramide.

Question 33

36 of 67

A 52 year old man undergoes a laparotomy for perforated bowel after a colonoscopy. 2 days after surgery the nursing staff report there is pink, serous fluid discharging from the wound. What is the next most appropriate management step?

Answer 33

Examine the wound for separation of the rectus fascia

The seepage of pink serosanguineous fluid through a closed abdominal wound is an early sign of abdominal wound dehiscence with possible evisceration. If this occurs, you should remove one or two sutures in the skin and explore the wound manually, using a sterile glove. If there is separation of the rectus fascia, the patient should be taken to the operating room for primary closure.

Question 34

37 of 67

A 45 year old man is involved in a polytrauma and requires a massive transfusion of packed red cells and fresh frozen plasma. Three hours later he develops marked hypoxia and his CVP is noted to be 10mm Hg. A chest x-rays shows bilateral diffuse pulmonary infiltrates. What is the most likely diagnosis?

Answer 34

Transfusion associated lung injury
………………………………………………………..
The risk of transfusion associated lung injury is greatest with plasma components.

Transfusion lung injury may occur after infusion of plasma components.
Microvascular damage occurs in the lungs leading to diffuse infiltrates on imaging.
Mortality is high.

Question 35

42 of 67

A 73 year old man undergoes a right below knee amputation for end stage peripheral vascular disease. He is reviewed in the clinic 8 weeks post operatively and complains of a persistent, burning discomfort over his amputation site stump.
On examination, his wound has healed and proximal pulses have a biphasic signal on doppler ultrasound. What is the most appropriate management?

Answer 35

Commence amitryptyline

This patient has neuropathic pain. Amitryptyline is the treatment of choice. Carbamazepine is mainly used for trigeminal neuralgia.

Question 35

38 of 67

A 48 year old man is due to undergo a laparotomy for small bowel obstruction. What is the best option for maintaining his airway?

Answer 35

Insertion of cuffed endotracheal tube
……………………………………………………….
Uncuffed endotracheal tubes are used in small children to reduce the risk of tracheal injury.

Patients who are due to undergo laparotomies for bowel obstruction have either been vomiting or at high risk of regurgitation of gastric contents on induction of anaesthesia. A rapid sequence induction with cricothyroid pressure applied to occlude the oesophagus is performed. A cuffed endotracheal tube is then inserted. Once correct placement of the ET tube is confirmed the cricothyroid pressure can be removed.

Question 35

39 of 67

A 50 year old man has an arterial blood gas sample taken and the following results are obtained, he is breathing room air.
pH 7.20
pO 7.5
HCO 22
pCO 8.1
Cl 10meq
Which of the conditions listed below is most likely to account for these findings?

Answer 35

Type 2 respiratory failure

This is a sign of acute type 2 respiratory failure (non compensated). This is the result of carbon dioxide retention.

Question 35

41 of 67

A homeless 42 year old male had an emergency inguinal hernia repair 24 hours previously. He has a BMI of 15. His electrolytes are normal. What is the best initial feeding regime?

Answer 35

Give 10 kcal/kg/day initially, oral thiamine 200-300mg/day, vitamin B co strong1 tds and supplements.

This patient is at high risk of refeeding syndrome.

Question 36

40 of 67

A 48 year old man is recovering on the high dependency unit following a long and complex laparotomy. His preoperative medication includes an ACE inhibitor for blood pressure control. For the past two hours he has been oliguric with a urine output of 10ml/hr . What the most appropriate immediate course of action?

Answer 36

Administer a fluid challenge

Hypovolaemia is the most likely cause for oliguria and a fluid challenge is the most appropriate action. Blind administration of inotropes to hypovolaemic patients is unwise, with the possible exception of cardiac patients.

Question 37

43 of 67

A 45 year old lady with cirrhosis of the liver is recovering following an emergency para umbilical hernia repair. She has been slow to resume oral intake and has been receiving regular boluses of normal saline for oliguria. Which of the following intravenous fluids should be considered?

Answer 37

Human albumin solution 4.5%

In patients who are hypoalbuminaemic the use of albumin solution may help promote a diuresis and manage fluid overload.

Question 38

44 of 67

Which of the following is a recognised feature of ketamine when used as an anaesthetic agent?

Answer 38

Dissociative anaesthesia

Unlike most anaesthetic agents ketamine does not cause myocardial or marked respiratory depression. It is not associated with the adrenal suppression that may occur with etomidate. It is however, associated with a state of dissociative anaesthesia which patients may find distressing.

Question 39

45 of 67

With which of the following blood products is iatrogenic septicaemia with a gram positive organism most likely?

Answer 39

Platelets

Platelets are stored at room temperature and must be used soon after collection.
This places them at increased risk of culturing gram positive organisms. Iatrogenic infection with gram negative organisms is more likely with packed red cells as these are stored at 4 degrees.
Infections with blood products of this nature are both rare.

Question 40

46 of 67

A 52 year old man is recovering following an elective right hemicolectomy for carcinoma of the caecum. His surgery is uncomplicated, when should oral intake resume?

Answer 40

Within 24 hours of surgery

As part of the enhanced recovery principles oral intake in this setting should resume soon after surgery. Administration of liquid and even light diet does not increase the risk of anastomotic leak.

Question 41

47 of 67

Which of the following is most suggestive of malnutrition?

Answer 41

Unintentional weight loss of > 10% over 3- 6 months in a 60 Kg female who is 1.6m tall

An unintentional weight loss of >10% in a three to six month period is highly suggestive of malnutrition. This is particularly true of people with a normal/ low BMI. Hypoalbuminaemia is not, in itself, a reliable marker of nutrition.

Question 42

48 of 67

A 78 year old man presents with a ruptured aortic aneurysm. This is repaired but the operation is difficult as it has a juxtarenal location. A supra renal cross clamp is applied. Post operatively he is found to be oliguric and acute renal failure is suspected. Which of the following statements relating to acute post-operative renal failure are untrue?

Answer 42

Intravenous dopamine does not prevent acute renal failure.
It is more common after emergency surgery.
Use of excessive amounts of intravenous fluids may lead to falsely normal serum creatinine measurements.
Vasopressor drugs have a strong renoprotective effect(Right)
It is minimised by normalisation of haemodynamic status.
…………………………………………….
Key points : Renal injury and acute renal failure: RIFLE Classification.
R=Risk (Serum Creatinine x1.5)
I=Injury (Serum Creatinine x 2)
F=Failure (Serum Creatinine x3)
L=Loss (Loss of renal function >4weeks)
E=End stage kidney disease

Vasopressor use is linked to renal failure as they are a marker of haemodynamic compromise.

Question 43

49 of 67

Which of the following muscle relaxants is an agent that is degraded by hydrolysis and may produce histamine release?

Answer 43

Atracurium

Atracurium is degraded by a process of ester hydrolysis. This uses non specific plasma esterases.

Question 44

50 of 67

You are the cardiothoracic surgical registrar reviewing a patient referred for an aortic valve replacement. The 40-year-old man is being investigated for progressive breathlessness in a previous respiratory clinic. The notes show he has smoked for the past 25 years. Pulmonary function tests reveal the following:
FEV1 1.4 L
FVC 1.7 L
FEV1/FVC 82%
What is the most likely explanation?

Answer 44

Kyphoscoliosis

These results show a restrictive picture, which may result from a number of conditions including kyphoscoliosis. The other answers cause an obstructive picture.
We note that most people have chosen COPD as the answer. In COPD the FEV1/FVC would show an obstructive picture with the FEV1/FVC value being low (approximately less than 70%). In restrictive conditions the FEV1/FVC is normal or increased (greater than 70%). With the FEV1/FVC being over 70% the most likely answer is kyphoscoliosis.

Question 45

51 of 67

Which of the following is a not a diagnostic criteria for brain death?

Answer 45

No response to sound(Right)
No corneal reflex
Absent oculo-vestibular reflexes
No response to supraorbital pressure
No cough reflex to bronchial stimulation

Question 45

53 of 67

A 22 year old lady undergoes a total thyroidectomy for Graves disease. 6 hours post operatively she develops respiratory stridor and develops a small haematoma in the neck. What is the most appropriate course of action?

Answer 45

Re-open the neck wound

This is true emergency and evacuation and release of pressure must be performed immediately, in this case by removal of skin clips on the ward. Attempts to access the airway surgically will delay this and can result in death.

Question 46

52 of 67

A 23 year old man is undergoing an open inguinal hernia repair as a daycase procedure and is being given sevoflurane. What is the best option for maintaining his airway during the procedure?

Answer 46

Insertion of laryngeal mask

This procedure will be associated with requirement for swift onset of anaesthesia and recovery. Muscle paralysis is not required and this would an ideal case for laryngeal mask airway.

Question 47

55 of 67

Administration of neostigmine to a patient who has received a non depolarizing muscle relaxant is most likely to result in which of the following?

Answer 47

Bradycardia

Neostigmine can cause bradycardia and atropine is often administered concomitantly to counter this effect.

Question 48

54 of 67

Which arterial blood gas sample best represents widespread mesenteric infarction?

Answer 48

pH 7.25, pO 8.9, pCO 3.2, HCO 10

This is usually associated with acidosis, hyperventillation and reduction in bicarbonate.

Question 49

59 of 67

A 63 year old man is commenced on an infusion of packed red cells following a total hip replacement. Which of the following adverse events is most likely?

Answer 49

Pyrexia

Mild pyrexia during blood transfusion is the most common event and commonly occurs during transfusion.

Question 50

56 of 67

A 54-year-old man is admitted for an elective hip replacement. Three days post operatively you suspect he has had a pulmonary embolism. He has no past medical history of note. Blood pressure is 120/80 mmHg with a pulse of 90/min. The chest x-ray is normal. Following treatment with low-molecular weight heparin, what is the most appropriate initial lung imaging investigation to perform?

Answer 50

Computed tomographic pulmonary angiography
………………………………………………..
CTPA is the first line investigation for PE according to current BTS guidelines

This is a difficult question to answer as both computed tomographic pulmonary angiography (CTPA) and ventilation-perfusion scanning are commonly used in UK clinical practice. The 2003 British Thoracic Society (BTS) guidelines, however, recommended that CTPA is now used as the initial lung imaging modality of choice. Pulmonary angiography is of course the ‘gold standard’ but this is not what the question asks for

Question 51

57 of 67

A 24 year old man is recovering from a right hemicolectomy for Crohns disease. He is oliguric and dehydrated owing to a high output ileostomy. His electrolytes are normal. Which of the following intravenous fluids should be administered?

Answer 51

Hartmanns solution

Of the solutions given Hartmans is the most suitable. Consideration should also be given to potassium supplementation.

Question 52

58 of 67

A patient with tachycardia and hypotension is to receive vasopressors. Which of the following conditions are most likely to be treated with vasopressors?

Answer 52

Septic shock

The term septic shock has a precise meaning and refers to refractory systemic arterial hypotension in spite of fluid resuscitation. Patients will therefore usually require vasopressors. Individuals suffering from neurogenic shock will usually receive intravenous fluids to achieve a mean arterial pressure of 90mmHg. If this target cannot be achieved then these patients will receive inotropes. Hypovolaemic shock requires fluids and the management of cardiogenic shock is multifactorial and includes inotropes, vasodilators and intra-aortic balloon pumps.

Question 53

60 of 67

A 32 year old man presents to the acute surgical unit with acute pancreatitis. Over the next few days he becomes dyspnoeic and his saturations are 89% on air. A CXR shows bilateral pulmonary infiltrates. His CVP pressure is 16mmHg. What is the most likely diagnosis?

Answer 53

Adult respiratory distress syndrome

Acute pancreatitis is known to precipitate ARDS. ARDS is characterised by bilateral pulmonary infiltrates and hypoxaemia. Note that pulmonary oedema is excluded by the CVP reading < 18mmHg.

Question 54

61 of 67

A 73 year old man develops disseminated intravascular coagulation following an abdominal aortic aneurysm repair. He receives an infusion of cryoprecipitate. What is the major constituent of this infusion?

Answer 54

Factor VIII

Question 55

62 of 67

A 44 year old man undergoes a distal gastrectomy for cancer. He is slightly anaemic and therefore receives a transfusion of 4 units of packed red cells to cover both the existing anaemia and associated perioperative blood loss. He is noted to develop ECG changes that are not consistent with ischaemia. What is the most likely cause?

Answer 55

Hyperkalaemia

The transfusion of packed red cells has been shown to increase serum potassium levels. The risk is higher with large volume transfusions and with old blood.

Question 56

63 of 67

A 53 year old man has an arterial blood gas sample taken and the following results are obtained, he is breathing room air.
pH 7.49
pO 8.5
HCO 22
pCO 2.4
Cl <10meq
Which of the conditions listed below is most likely to account for these findings?

Answer 56

Respiratory alkalosis

The hyperventilation results in decreased carbon dioxide levels, causing a respiratory alkalosis (non compensated).

Question 57

64 of 67

A 56 year old man is on the ward 5 days following a high anterior resection for a carcinoma of the recto sigmoid junction. Over the past 12 hours, he has developed increasing lower abdominal pain, a fever of 37.8 C and fast atrial fibrillation. Of the investigations listed below, which is likely to be the most useful?

Answer 57

Abdominal CT scan

New AF following a colonic resection is most likely to represent an anastomotic leak and this will be best seen on CT scanning.

Question 58

65 of 67

Which of the drugs listed below confers the greatest risk of malignant hyperthermia?

Answer 58

Suxamethonium

Suxamethonium may cause malignant hyperthermia and 1 in 2800 will have abnormal cholinesterase enzyme and prolonged clinical effect.

Question 59

66 of 67

A 22 year old lady is admitted to the intensive care unit following a laparotomy. She has a central line, pulmonary artery catheter and arterial lines inserted. The following results are obtained:
Pulmonary artery occlusion pressure: Low
Cardiac output:High
Systemic vascular resistance:Low
How may these findings be best interpreted?

Answer 59

Septic shock

Decreased SVR is a major feature of sepsis. A hyperdynamic circulation is often present. This is the reason for the use of vasoconstrictors.

Question 60

67 of 67

Which of the arterial blood gas analyses shown below would most likely be seen with a patient who has a pulmonary embolus?

Answer 60

pH 7.50, pO 7.2, pCO 2.5, HCO 24

A combination of hypoxia and respiratory alkalosis should suggest a pulmonary embolus. The respiratory alkalosis is due to hyperventilation associated with the pulmonary embolism.