Exam Questions

Question 1

Explain the mechanism of action of Local anesthetic drugs. (3 marks)

Answer 1

Local anesthetic drugs bind on the sodium channel blocking the sodium influx resulting in no depolarization of the cell. No depolarization means No propagation of Action potential or impulses. That results in loss of sensory, motor, and autonomic stimulation of the local area

Question 2

Explain the mechanism of action of ACE (Angiotensin Converting Enzyme) inhibitors. (3 marks)

Answer 2

It inhibits conversion of Angiotensin I into Angiotensin II. Angiotensin II is a potent vasoconstrictor and stimulates the release of aldosterone. Decreased Angiotensin II levels causes decreased vasopressor activity and reduced aldosterone secretion, which decreases blood pressure.

Question 3

Mention the principal mechanism of action of diuretics (2marks)

Answer 3

Some diuretics block reabsorption of sodium from the distal tubules, then accumulation of sodium in the tubules pulls water from the blood circulation resulting in decrease in circulatory volume thus decreasing blood pressure.

Question 4

Mention four(4) common side effects of Tenofovir. (4 marks)

Answer 4

1. Skin rash
2. Headaches
3. Hepatoxicity
4. Vomiting

Question 5

Mention four(4) common side effects of Efavirenz. (4 marks)

Answer 5

1. Hallucination
2. Liver toxicity
3. Skin rash
4. Vomiting

Question 6

List four (4) advantages of spinal over general anaesthesia for caesarean section. (2 marks)

Answer 6

1. The preservation of consciousness
2. Practicality an
3. Affordability
4. Quicker post-operative recovery

Question 7

List four (4) absolute contraindications to spinal anaesthesia. (2 marks)

Answer 7

1. Patient refusal
2. Severe Hypovolaemia
3. Raised intracranial pressure
4. Coagulopathy
5. Infection in site of injection

Question 8

What are the reasons for giving the following premedication to a patient prior to caesarean section? (2 marks)

Answer 8

A. Sodium citrate- In order to reduce the acidity of the stomach contents.

B. Metoclopramide- This prevents patient from vomiting and aspiration during c-section, causes gastric emptying and prevents esophageal reflux

Question 9

A 24-year-old male presents with a deep laceration on the left calf following a fall. The wound is to be sutured under local anaesthesia. Immediately following the infiltration of the wound with 2% Lignocaine, the patient complained of lip numbness and becomes very apprehensive.

1. What is the most likely cause of the patients symptoms? (1 mark)
2. Outline six (6) immediate actions you need to take for the management of the patient. (6 marks)

Answer 9

1. Toxicity

2.
° Cease administration of LA
° Call for help 
° ABC: Oxygenate
° Infuse IV fluids 
° Control convulsions: Diazepam, IV, 10 mg
° Hypotension: give IV fluids & vasoconstrictor( Adrenaline) 
°For cardiac arrest: start CPR

Question 10

A 30-year-old female on oral contraceptive is diagnosed with Pulmonary TB and is to commence treatment.

1. Which of the TB drugs can have an interaction with oral contraceptive pills? (1 mark)
2. Explain the mechanism of the interaction with oral contraceptive pills (OCP) and the above mentioned anti-TB drug. (2 marks)
3. What advice should be given to this patient with regards to contraceptives (1 mark)
4. List five (5) Features that will suggest possible difficult bag-mask ventilation. (5 marks)

Answer 10

1. Rifampicin
2. They are both metabolized in the liver, thus giving both drugs there would be drug-to-drug interaction and the Oral contraceptive won’t be able to do its function properly.
3. Patient must insert Inter Uterine Device as a form of contraceptive.

4.
• Pregnant and obese patients
•Patient with restricted neck movement
• A person with a short, thick “bull neck”
• A person with protruding incisors
• A person with oro-pharyngeal trauma, a dental abscess, or angio-neurotic oedema may make the insertion difficult.

Question 11

A 40-year-old man, on antiretroviral therapy (TDF/FTC/EFV) for five (5) years presents with bilateral, painless breasts enlargement. His other medications include Cotrimoxazole and Enalapril. The clinA suspects a side-effects from the antiretroviral drugs .

1. What is this condition called? (1 mark)
2. Which of the antiretroviral drug is the likely cause? (1 mark)
3. What class of antiretroviral drug does it belong to? (1 mark)

Answer 11

1. Gynaecomastic
2. Efavirenz (EFV)
3. Non- Nucleus Reverse Transcriptase Inhibitor (NRTI)

Question 12

What is the role or benefits of adrenaline in Lignocaine? (3 marks)

Answer 12

° Adrenaline is a vasoconstrictor, causes Vasoconstriction at the site of administration. This leads to:
° Reduction in the rate of absorption of LA
° Enhancing the quality of analgesia
• Prolong duration of action
• Limits toxic side effects

Question 13

What is the effect of Dextrose in Bupivacaine solution and how does this affect the level of the spinal block? (6marks)

Answer 13

°Dextrose in Bupivacaine increases Baricity.
° It becomes Hyperbaric
° The pts position in the few minutes after injection are crucial in determining block height
°Giving a spinal with the pt in a sitting position will produce a lower block than if the patient is lying down
° Never place the pt in a head-down position after spinal injection with heavy Bupivacaine to prevent spread higher than mid-thoracic dermatomes.
°Always make sure the pts head and shoulders are elevated above the level of the pelvis.

Question 14

You are requested to assist appendectomy with General anesthesia for a 40-year-old man.

1. Explain the reason for administering 100% oxygen to a patient several minutes prior to endotracheal intubation. (2marks)
2. The patient is to be given Suxamethonium as a muscle relaxant, what is the effect of a muscle relaxant during general anesthesia? (1 mark)
3. Where is the site of action of muscle relaxants? (1mark)
4. What type of muscle relaxant is Suxamethonium? (1 mark)
5. Mechanism of Action of Suxamethonium? (2marks)

Answer 14

1. Pre-oxygenation before induction, is designed to increase the body oxygen stores and thereby delay the onset of arterial hemoglobin desaturation during apnea. Thus giving you more time to rescue the situation if things go wrong.
2. Used to facilitate endotracheal intubation.
3. Neuromuscular
4. Depolarising (short-acting) relaxant
5. Causes persistent depolarization of the neuromuscular junction. Thus leading to desensitization.

Question 15

A 24-year-old female presents st the OPD with an abscess n the right foot. Incision and drainage is to be done under local anaesthesia.

1. Explain why the patient might still feel pain despite the correct infiltration of the abscess with Lignocaine

Answer 15

1. Delay of onset, some local blocks can take as long as fifteen to twenty minutes to work before the patient is ready for surgery.

Question 16

Complete the table below indicating the effect of the following adjuncts on local anaesthetic drugs. (3 marks)

Answer 16

LA+ Adjuncts. Effect

1. Lignocaine+ Adrenaline - It reduces the speed of systemic absorption and the incidence of side-effects.
2. Bupivacaine+Glucose- Glucose increases Bupivacaine baricity. Thus becoming Hyperbaric
3. Lignocaine+sodium bicarbonate- Neutralizes the Lignocaine thus as to increasig the onset of Lignocaine

Question 17

A clinical associate has been assigned to monitor the patients during Spinal anaesthesia in theatre. She prepared the equipment appropriately and worked with her supervising medical practitioners. Shortly after starting the third operation, the patient’s oxygen saturation dropped to 55%. On examination, the patient has no chest movement nor any breath sounds.

List 8 important pieces of equipment the clinical associate should have prepared to manage this specific situation.

Answer 17

1. Bag & Mask
2. Endotracheal tube
3. Laryngoscope
4. Laryngeal mask airway
5. Orapahyngeal-airway
6. Suction
7. Pulse oxymetry
8. Magil forceps
9. Oxygen source
10. Emergency drugs
11. ABG

Question 18

PURPOSE of pre-anesthetic assessment

Answer 18

1. Identify patients whose outcomes likely will be improved by the implementation of a specific medical treatment
2. Identify patients whose condition is so poor that the proposed surgery might hasten death without improving quality of life
3. Identify those with specific characteristics that likely will influence the anaesthetic plan
4. Provide patients with an estimate of anesthetic risk
5. Opportunity to provide information to the patient about the proposed anesthesia and obtain informed consent

Question 19

A female undergoing C-section. BP drops from 124/35mmHg to 88/40mmHg. A bolus 500ml IV fluids has been given. Her BP is now 85/40mmHg

List drug name, dose and route of drug needed to be administratored

Answer 19

Ephedrine, IV, 5-10mg

Question 20

Other than Hypotension and nausea list 3 spinal complications.

Answer 20

1. High Spinal
2. Urinary retention
3. Bradycardia

Question 21

1. Explain why Lignocaine is less effictive in abscess? (2 marks)
2. What substances is to be added to increase the efficiency of Lignocaine in incision and drainage of the abscess? (1 mark)

Answer 21

1. ° Abscess has increased acidity making Lignocaine to penetrate slowly
   ° Lignocaine functions poorly in presence of infection and inflammation.
2. Sodium bicarbonate

Question 22

Suxamethonium

1. Drug class. (1 mark)
2. Duration (how long does it last) (1 mark)

Answer 22

1. Depolarising muscle relaxant

2. Lasts 3-5 minutes

Question 23

1. What is the phenomenon where a patients appears conscious under the effect of ketamine called?
2. Two contra-indications of Ketamine

Answer 23

1. Excitatory and hallucinatory phenomena may occur during emergence from Anasthesia
2. Hypertension
   °Cardiac failure
   ° recent MI
   °Raised intracranial pressure

Question 24

A Doctor is intubating a patient and accidentally touched the trachea result to the patient coughing non-stop. Explain the mechanism of action of Cough

Answer 24

Cough: vagal pulmonary receptors sense mechanical & /chemical stimulus in the airway and transmit signals back to the brainstem and cortex, initiating the cough reflex

Question 25

Mention 4 measures you need to take to prepare the patient before spinal anesthesia for a c-section.

Answer 25

1. Ensure history to detect drug hypersensitivities or comorbidities 2. Complete physical examination to detect comorbidities or hypovolemia 3. Pre-medication (Sodium citrate and Metoclopramide) 4. IV access with 500ml clear fluid as preload 5. Urinary catheter

Question 26

List 6 commonly encountered side effects associated with Benzodiazepine derivatives drug class

Answer 26

1. Over sedation 2. Respiratory depression/arrest 3. Ataxia 4. Amnesia 5. Hypotension 6. Nausea and vomiting 7. Dependence

Question 27

What is the effect of Dextrose in Bupivacaine solution and how does this affect the level of the spinal block? (6marks)

Answer 27

1. Addition of glucose to bupivacaine increases the specific gravity of the local anesthetics relative to the specific gravity of the CSF, making it hyperbaric. 2. Hyperbaric solution (such heavy bupivacaine) tends to move to the most dependent area of the spine. 3. With normal anatomy, the apex of the thoracolumbar region is T4, in the supine position, this limits heavy bupivacaine to produce a block at or below T4.

Question 28

Explain the mechanism of action of Local anesthetic drugs. (3 marks)

Answer 28

* LA binds to sodium ions→ inhibits sodium channels→on the cell membrane of nerve cells * They prevent sodium influx→ associated with membrane depolarization→ * By preventing the generation of an action potential (depolariztion)→impulse generation in the nerve is abolished.