Mcq Anaesthesia Questions

Self Assessment Questions from ‘Update 10’

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Dr Andrew Longmate, Edinburgh Royal Infirmary UK. The following Multiple Choice Questions (MCQ) questions assess your knowledge about issues covered in “Update in Anaesthesia”. 1. a) b) c) d) e)

A low alveolar PO2 may be caused by shivering breathing a hypoxic mixture of gases a decreased minute volume ventilation / perfusion mismatch uncomplicated cardiac failure

2. a) b) c) d) e)

Blood in the following vessels usually has an oxygen haemoglobin saturation greater than 90% pulmonary artery aorta inferior vena cava pulmonary veins halfway along the pulmonary capillary

3. a) b) c) d) e)

Oxygen consumption is increased in malignant hyperpyrexia is increased under general anaesthesia in health, is critically dependent on oxygen delivery is approximately 2L/min in the resting adult when increased, causes a decrease in the mixed venous PO2 (assume oxygen delivery remains constant)

4. a) b) c) d) e)

Oxygen stores are increased slightly by pre-oxygenation are large because oxygen is so important for cellular function depend in part on blood volume and haemoglobin concentration are large in pregnant women compared to non-pregnant women can be accurately assessed with a pulse oximeter

5. a) b) c) d) e)

The following commonly contribute to poor oxygenation during general anaesthesia hyperventilation atelectasis ventilation / perfusion mismatch hypersensitive chemoreceptors increased metabolic rate

Update in Anaesthesia Issue 10 (1999)

© World Anaesthesia

Self Assessment Questions from ‘Update 10’

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6. a) b) c) d) e)

40% oxygen via a facemask is appropriate oxygen therapy for a patient with a shunt equivalent to 40% of cardiac output due to pneumonia a reduced minute volume due to opioid analgesia complete upper airway obstruction hypovolaemic shock ischaemic heart disease following uncomplicated major surgery

7. a) b)

e)

Pre-oxygenation can be started in the ward prior to coming to theatre as part of a rapid sequence induction occurs following induction of anaesthesia but before intubation of the trachea causes a significant increase in the oxygen bound to haemoglobin in the blood should take place through an anaesthetic circuit and a high oxygen flow rate and the mask held just off the face allows for acceptable oxygenation during 10 minutes of apnoea

8. a) b) c) d) e)

The PO2 in the trachea while breathing air is about 150 mmHg in the arterial blood while breathing air is about 100 mmHg (13 kPa) in the alveoli can exceed 600 mmHg when breathing 100% oxygen of venous blood may fall when cardiac output is very low in the mitochondria in the brain is higher than in venous blood

9)

e)

After recent significant head injury with loss of consciousness and a period of decreased GCS, suitable anaesthetic techniques for fixation of fractured elbow include: local anaesthetic block spontaneous ventilation with 2% halothane intravenous ketamine ventilation with a low concentration of whatever volatile agent is available to you (eg 0.5% halothane) avoidance of suxamethonium

10) a) b) c) d) e)

Difficult intubation is associated with: a short thick neck limited mouth opening dental abscess limited neck movements a Mallampati grade 1

c) d)

a) b) c) d)

Update in Anaesthesia Issue 10 (1999)

© World Anaesthesia

Self Assessment Questions from ‘Update 10’

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11) a) b) c) d) e)

Strategies that can be used in patients likely to be a difficult intubation include: regional anaesthesia inhalational induction and spontaneous ventilation with a volatile agent paralysis with alcuronium or pancuronium after intravenous thiopentone. awake intubation cautious intravenous anaesthesia using ketamine

12) a) b) c) d) e)

Interscalene block is good for hand surgery is likely to work when paraesthesia or twitchesoccur over the shoulder. is useful for operations on the shoulder or upper arm can be used to reduce dislocated shoulder frequently blocks the phrenic nerve

13) a) b) c) d) e)

A fit occurring in association with placement of a major local anaesthetic block may be due to direct injection of local anaesthetic into a blood vessel may be because too big a dose of local anaesthetic has been given should be managed by giving oxygen and maintaining the airway if the fit does not stop may be treated with thiopentone or diazepam may be associated with cardiac arrhythmias or arrest

14) a) b) c) d) e)

Pre-oxygenation in pregnant women is especially important because: intubation may be difficult they have a reduced lung volume (decreased FRC-functional residual capacity) they use up oxygen faster than non pregnant patients can be achieved by breathing oxygen for 3 minutes with a tight fitting face mask. can be achieved by performing 3 vital capacity breaths of 100% oxygen

15)

Agents which may be given at the time of induction of general anaesthesia for Caesarean section when there is pre-eclampsia include: thiopentone etomidate magnesium sulphate alfentanil ketamine

a) b) c) d) e)

16) a) b) c) d) e)

A pregnant patient complains of difficulty breathing and tingling in the arms soon after a spinal with heavy bupivacaine for Caesarean section. Actions to perform include: place the patient head down give oxygen and be ready to control the airway speed the iv infusion up place a pillow under the head and shoulders leave the room to continue scrubbing up for surgery.

Update in Anaesthesia Issue 10 (1999)

© World Anaesthesia

Self Assessment Questions from ‘Update 10’ 17)

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a) b) c) d) e)

Contraindications to the use of NSAIDs (non-steroidal anti-inflammatory drugs) for the control of pain include: renal failure all asthmatic patients patients actively bleeding old and frail patients patients with peptic ulcer

18) a) b) c) d) e)

Concerning pain relief in children: they have no need for pain relief morphine is too dangerous to give NSAIDs should not be used paracetamol is too weak to be useful local anaesthetic blocks are useful

19) a) b) c) d) e)

Features of an anaphylactic reaction include: low blood pressure diarrhoea wheezing flushed appearance swelling around the face and airway

20) a) b) c) d) e)

Treatment of an anaphylactic reaction includes: adrenaline steroids iv fluids antihistamine antibiotics

21) a) b) c) d) e)

Causes of a fast pulse (greater than 100) include: pain ketamine hypovolaemic shock atropine fever

22) a) b) c) d)

Causes of a slow pulse (less than 50 beats per minute) include: hypoxia neostigmine cervical dilatation vasovagal episodes

Update in Anaesthesia Issue 10 (1999)

© World Anaesthesia