Stop & Think

SECTION A

1. Atracurium is primarily metabolized by

1. Kidney

2. Liver

3. Hoffman elimination

4. Pseudocholinesterase

5. Nonspecific esterases
   Answer: c. Hoffman elimination
   Explanation: Atracurium undergoes spontaneous degradation in plasma and tissues via Hofmann elimination, which is temperature and pH dependent, making it suitable for patients with renal or hepatic dysfunction.

2. Which of the following agents is not suitable for gaseous induction in children?

1. Halothane

2. Sevoflurane

3. Isoflurane

4. Nitrous oxide

5. None of the above
   Answer: c. Isoflurane
   Explanation: Isoflurane is pungent and can cause airway irritation, making it less suitable for smooth inhalational induction, especially in children. Sevoflurane, on the other hand, is non-pungent and ideal for pediatric induction.

3. Concerning side effects of Etomidate

1. Causes nausea and vomiting

2. Laryngospasm

3. Bronchospasms

4. Hypertension

5. Rhabdomyolysis
   Answer: a. Causes nausea and vomiting
   Explanation: Etomidate is known for preserving cardiovascular stability, but its side effects include nausea, vomiting, myoclonus, and adrenal suppression. It’s not associated with rhabdomyolysis or significant bronchospasm.

4. Rapid sequence induction can be accomplished with which muscle relaxant?

1. Rocuronium

2. Atracurium

3. Pancuronium

4. Vecuronium

5. None of the above
   Answer: a. Rocuronium
   Explanation: Rocuronium, at higher doses, has a rapid onset similar to suxamethonium and is ideal for rapid sequence induction, especially when suxamethonium is contraindicated.

5. Total intravenous anaesthesia (TIVA) was given for the craniotomy. Which of the following drugs is appropriate for TIVA?

1. Thiopentone

2. Midazolam

3. Propofol

4. Ketamine

5. Fentanyl
   Answer: c. Propofol
   Explanation: Propofol is the primary agent for TIVA due to its rapid onset, short duration, antiemetic properties, and easy titration. It's commonly combined with short-acting opioids for balanced anaesthesia.

6. Ketamine has a neuro-protective benefit that works through the antagonism of which of the following ions?

1. Calcium

2. Potassium

3. Sodium

4. Magnesium

5. None of the above
   Answer: d. Magnesium
   Explanation: Ketamine is an NMDA receptor antagonist. It blocks the receptor at the magnesium site, reducing excitotoxicity and offering neuroprotection, especially useful in cases of traumatic brain injury.

7. Which one of the following is NOT true about bupivacaine?

1. Used in spinal anaesthesia

2. Local wound infiltration

3. Epidural anaesthesia

4. Nerve blocks

5. Used in intravenous regional anaesthesia
   Answer: e. Used in intravenous regional anaesthesia
   Explanation: Bupivacaine is contraindicated in intravenous regional anaesthesia (Bier’s block) due to the risk of cardiotoxicity if systemic absorption occurs.

8. The following is NOT true about Morphine:

1. Causes ventilatory depression

2. Causes miosis

3. Constipation

4. Nausea and vomiting

5. Modest increase in cerebral metabolic rate
   Answer: e. Modest increase in cerebral metabolic rate
   Explanation: Morphine generally decreases cerebral metabolic rate and intracranial pressure. It is known for respiratory depression, miosis, constipation, and nausea, but not for raising cerebral metabolism.

9. A four-year-old male child with muscular dystrophy was booked for exploratory laparotomy. Which of the following muscle relaxants is best avoided?

1. Pancuronium

2. Vecuronium

3. Rocuronium

4. Suxamethonium

5. Atracurium
   Answer: d. Suxamethonium
   Explanation: Suxamethonium is contraindicated in muscular dystrophy due to the risk of life-threatening hyperkalemia and cardiac arrest from upregulated acetylcholine receptors.

10. Which one of the following is a factor that could alter the duration of action of atracurium?

1. Temperature

2. Weight of the patient

3. Duration of the surgery

4. Surgery at mid-day

5. Atropine
   Answer: a. Temperature
   Explanation: Atracurium undergoes Hofmann elimination, which is temperature and pH dependent. Hypothermia slows down this process, prolonging its action.

11. The following drug could penetrate the placenta:

1. Pethidine

2. Atracurium

3. Suxamethonium

4. Pancuronium

5. Rocuronium
   Answer: a. Pethidine
   Explanation: Pethidine is a lipid-soluble opioid, which allows it to cross the placental barrier. Most muscle relaxants like atracurium and suxamethonium are ionized and do not easily cross.

12. Which of the following is the most common effect of a second dose of suxamethonium?

1. Tachycardia

2. Bradycardia

3. Hypertension

4. Malignant hyperthermia

5. Suxamethonium apnea
   Answer: b. Bradycardia
   Explanation: A second dose of suxamethonium, especially in children, can stimulate muscarinic receptors in the heart, resulting in bradycardia. Atropine is often used to mitigate this.

13. Which inhalational anaesthetic is associated with coronary steal syndrome:

1. Halothane

2. Isoflurane

3. Sevoflurane

4. Desflurane

5. Enflurane
   Answer: b. Isoflurane
   Explanation: Isoflurane causes vasodilation in normal coronary vessels, potentially diverting blood away from stenotic areas—a phenomenon called coronary steal. It's more theoretical but still worth noting.

14. The following are contraindications to the use of suxamethonium EXCEPT:

1. Hyperkalemia

2. History of malignant hyperthermia

3. Hypertensive patients

4. Paraplegia

5. Burns more than 48 hours
   Answer: c. Hypertensive patients
   Explanation: Hypertension is not a contraindication to suxamethonium. However, conditions associated with upregulation of nicotinic acetylcholine receptors (like burns, paraplegia) can lead to dangerous hyperkalemia.

15. The following agents decrease the heart rate EXCEPT:

1. Diltiazem

2. Neostigmine

3. Halothane

4. Phenylephrine

5. Ephedrine
   Answer: e. Ephedrine
   Explanation: Ephedrine is a sympathomimetic that increases heart rate and blood pressure. The rest can either cause bradycardia directly or through reflex mechanisms.

16. Which one of the following drugs is primarily used for management of bradycardias during anaesthesia:

1. Atropine

2. Neostigmine

3. Phenylephrine

4. Dopamine

5. Noradrenaline
   Answer: a. Atropine
   Explanation: Atropine is an anticholinergic that blocks vagal stimulation of the heart, making it the first-line agent for treating bradycardia during anaesthesia.

17. Considering malignant hyperthermia during anaesthesia, which of the following is CORRECT:

1. Sevoflurane is a precipitant

2. The incidence is about 1 in 50 anaesthetics

3. Propofol is a precipitant

4. Fentanyl is a precipitant

5. Hypocapnia is an early sign
   Answer: a. Sevoflurane is a precipitant
   Explanation: Volatile agents like sevoflurane and suxamethonium can trigger malignant hyperthermia, a life-threatening hypermetabolic state. Propofol and fentanyl are safe. Hypercapnia, not hypocapnia, is an early sign.

18. The following is TRUE concerning Propofol:

1. Is an intravenous induction agent

2. Does not cause pain on injection

3. Used for the treatment of bradycardia during anaesthesia

4. Causes hangover effects

5. Causes postoperative nausea and vomiting
   Answer: a. Is an intravenous induction agent
   Explanation: Propofol is a widely used induction agent known for rapid onset and recovery. However, it can cause pain on injection and actually reduces postoperative nausea and vomiting due to its antiemetic properties.

19. Premedication:

1. Reduces postoperative complications

2. Reduces anxiety

3. Reduces pain during anaesthesia

4. Is indicated for patients planned for spinal anaesthesia

5. All of the above
   Answer: e. All of the above
   Explanation: Premedication serves several roles, including anxiolysis, analgesia, antiemesis, and reduction of physiological stress—especially important in spinal anaesthesia where anxiety might be heightened.

20. Concerning hypovolaemic shock and anaesthesia, which of the following is CORRECT?

1. Ketamine is the best choice for induction

2. Propofol is always best for induction

3. Atracurium is the first choice for paralysis

4. Surgery should go ahead even if patient is not volume resuscitated

5. Fluid resuscitation with dextrose containing fluid is indicated
   Answer: a. Ketamine is the best choice for induction
   Explanation: Ketamine maintains cardiovascular stability by stimulating sympathetic tone, making it the induction agent of choice in hypovolaemic shock. Propofol would cause dangerous hypotension in this setting.

21. Antacid premedication in the parturient should be carried out with:

1. Aluminium hydroxide

2. Magnesium trisilicate

3. Magnesium hydroxide

4. Sodium citrate

5. None of the above
   Answer: d. Sodium citrate
   Explanation: Sodium citrate is used in obstetric anaesthesia as a non-particulate antacid. It raises gastric pH rapidly, reducing the risk of acid aspiration (Mendelson’s syndrome) during emergency Caesarean section.

22. Suxamethonium is contraindicated for routine tracheal intubation in children because of an increased incidence of which of the following side effects:

1. Hyperkalemia

2. Malignant hyperthermia

3. Masseter spasms

4. Sinus bradycardia

5. Severe myalgia
   Answer: a. Hyperkalemia
   Explanation: Children, particularly those with undiagnosed muscular dystrophies, are at risk of severe hyperkalemia from suxamethonium, which can precipitate fatal arrhythmias.

23. Which of the following muscle relaxants is most suitable for rapid intubation in a patient in whom suxamethonium is contraindicated:

1. Mivacurium

2. Rocuronium

3. Doxacurium

4. Pipercuronium

5. Vecuronium
   Answer: b. Rocuronium
   Explanation: Rocuronium at high doses offers rapid onset comparable to suxamethonium and is ideal for rapid sequence induction when suxamethonium is contraindicated.

24. Which of the following intravenous anaesthetic agents is associated with the highest incidence of nausea and vomiting?

1. Thiopentone

2. Etomidate

3. Propofol

4. Ketamine

5. Midazolam
   Answer: b. Etomidate
   Explanation: Despite its cardiovascular stability, Etomidate is notorious for postoperative nausea and vomiting and adrenal suppression—limiting its use in longer or elective surgeries.

25. Which of the following muscle relaxants is appropriate for paralyzing an asthmatic patient?

1. Pancuronium

2. Atracurium

3. Mivacurium

4. D-tubocurarine

5. None of the above
   Answer: b. Atracurium
   Explanation: Atracurium is relatively safe in asthmatics, though caution is needed due to histamine release at high doses. D-tubocurarine and Mivacurium are more likely to trigger bronchospasm through histamine release.

SECTION B

1. State the contraindications for spinal anaesthesia. (5 marks)

• Patient refusal

• Coagulopathy or anticoagulation therapy

• Infection at the puncture site

• Raised intracranial pressure (especially with mass lesions)

• Severe hypovolemia or shock

Explanation: These factors increase the risk of complications such as spinal hematoma, brainstem herniation, or hemodynamic collapse.

2. Write on the objectives of premedication. (5 marks)

7 A’s of premedication

• 1. Anxiolysis – Midazolam
  → A short-acting benzodiazepine that relieves preoperative anxiety and induces sedation.

• 2. Amnesia – Midazolam
  → Also serves here due to its strong anterograde amnesic properties—patients won’t remember stressful moments before induction.

• 3. Analgesia – Fentanyl
  → A potent opioid that provides preemptive pain relief and reduces anaesthetic requirements.

• 4. Anti-emesis – Ondansetron
  → A 5-HT3 antagonist that effectively prevents nausea and vomiting, especially useful postoperatively.

• 5. Anti-secretory effects – Glycopyrrolate
  → An anticholinergic that reduces oral and respiratory tract secretions with minimal CNS effects.

• 6. Autonomic stability – Atropine
  → Counteracts bradycardia and vagal responses during airway manipulation.

• 7. Aspiration prophylaxis – Sodium citrate
  → A non-particulate antacid that neutralizes gastric acid, reducing the risk of acid aspiration.

3. State the side effects of Suxamethonium. (5 marks)

• Hyperkalemia

• Bradycardia (especially with repeated doses)

• Malignant hyperthermia

• Raised intraocular and intracranial pressures

• Postoperative myalgia

Explanation: Suxamethonium, while effective for rapid intubation, carries significant risks particularly in susceptible individuals, requiring careful patient selection.

Question 1:
Cardiac output is greatest:
Options:
a. During the first trimester of pregnancy
b. During the second trimester of pregnancy
c. During the third trimester of pregnancy
d. During labour
e. Immediately after the delivery of the baby

Correct Answer: b. During the second trimester of pregnancy

Explanation:
Cardiac output peaks during the second trimester (up to 50% increase) due to increased blood volume and decreased systemic vascular resistance. It remains elevated but may slightly decline in the third trimester due to mechanical compression by the gravid uterus.

Question 2:
Which one of the following will produce uterine relaxation?
Options:
a. Sevoflurane
b. Nitrous oxide
c. Fentanyl
d. Thiopentone
e. Diclofenac

Correct Answer: a. Sevoflurane

Explanation:
Volatile anesthetics (e.g., sevoflurane) cause dose-dependent uterine relaxation, which is useful in procedures like fetal surgery or retained placenta. Nitrous oxide (b) has minimal effects on uterine tone.

Question 3:
Which one of the following side effects of spinal anesthesia is associated with the use of large-bore spinal needles?
Options:
a. Hypotension
b. Bradycardia
c. Postdural puncture headache (PDPH)
d. Shivering
e. High spinal

Correct Answer: c. Postdural puncture headache (PDPH)

Explanation:
PDPH is caused by CSF leakage through the dural puncture. Larger needles increase the risk. Hypotension (a) and bradycardia (b) are physiological responses to sympathetic blockade, unrelated to needle size.

Question 4:
The following adverse effects are associated with aortocaval compression by the gravid uterus EXCEPT:
Options:
a. Nausea and vomiting
b. Decreased uterine blood flow
c. Pallor
d. Changes in cerebration/mentation
e. Fever

Correct Answer: e. Fever

Explanation:
Aortocaval compression causes hypotension, reduced venous return, and cerebral hypoperfusion (a–d). Fever is unrelated and suggests infection or other pathology.

Question 5:
Ketamine:
Options:
a. Has analgesic properties mediated by its binding to NMDA receptors
b. Causes a fall in cardiac output and a decrease in heart rate
c. Is not contraindicated in patients with increased intracranial pressure
d. Has no active metabolites
e. Does not cause postoperative hallucinations

Correct Answer: a. Has analgesic properties mediated by its binding to NMDA receptors

Explanation:
Ketamine is an NMDA receptor antagonist, providing analgesia and dissociative anesthesia. It increases heart rate and blood pressure (b), is contraindicated in elevated ICP (c), and can cause hallucinations (e). Its metabolite, norketamine, is active (d).

Question 6:
Lidocaine:
Options:
a. Is used as an anti-arrhythmic drug
b. Is more potent than bupivacaine
c. It is not an effective antiarrhythmic drug when administered intravenously
d. Is an acid
e. Does not cause epileptiform fits when given intravenously in large doses

Correct Answer: a. Is used as an anti-arrhythmic drug

Explanation:
Lidocaine is a Class IB antiarrhythmic. Bupivacaine (b) is more potent and toxic. IV lidocaine can cause seizures at high doses (e) and is a weak base (d).

Question 7:
Propofol:
Options:
a. Is an imidazole derivative
b. Has cardiac stability
c. Causes pain on injection
d. Causes nausea and vomiting
e. Is not used for sedation in ICU

Correct Answer: c. Causes pain on injection

Explanation:
Propofol is a phenol derivative (a), causes myocardial depression (b), and is widely used for ICU sedation (e). Pain on injection is common (c), but it has anti-emetic properties (d).

Question 8:
Features of depolarizing block by suxamethonium:
Options:
a. No fasciculations
b. Long duration of action
c. Are competitive inhibitors
d. Antagonism by anticholinesterases
e. A rise in intracranial pressure

Correct Answer: e. A rise in intracranial pressure

Explanation:
Suxamethonium causes fasciculations (a), has a short duration (b), and is not antagonized by anticholinesterases (d). It increases ICP (e) due to muscle fasciculations.

Question 9:
Induction with ketamine is contraindicated in:
Options:
a. Asthmatic patients
b. For cesarean section
c. A patient with facial burns
d. In a hypertensive patient
e. In a shocked patient

Correct Answer: d. In a hypertensive patient

Explanation:
Ketamine increases blood pressure and is contraindicated in hypertension (d). It is safe in asthma (a), shock (e), and burns (c).

Question 10:
The following is an anticholinesterase:
Options:
a. Atropine
b. Glycopyrrolate
c. Neostigmine
d. Ranitidine
e. Prilocaine

Correct Answer: c. Neostigmine

Explanation:
Neostigmine inhibits acetylcholinesterase, reversing neuromuscular blockade. Atropine (a) and glycopyrrolate (b) are anticholinergics.

Question 11:
The following factors encourage the passage of a drug across the cell membrane:
Options:
a. High lipid solubility
b. Low concentration gradient
c. High molecular weight
d. Negative hydrostatic pressure
e. High degree of ionization

Correct Answer: a. High lipid solubility

Explanation:
Drugs with high lipid solubility cross cell membranes more easily. Factors like low concentration gradient (b), high molecular weight (c), and high ionization (e) hinder passage.

Question 12:
The MAC value of:
Options:
a. Isoflurane is greater than that of halothane
b. Halothane is greater than that of sevoflurane
c. Halothane is greater than that of desflurane
d. Sevoflurane is greater than that of desflurane
e. Isoflurane is greater than that of sevoflurane

Correct Answer: b. Halothane is greater than that of sevoflurane

Explanation:
MAC values (potency inversely related):

• Sevoflurane (2.0%) > Halothane (0.75%) > Desflurane (6.0%) > Isoflurane (1.2%).
  Halothane has a lower MAC (more potent) than sevoflurane.

Question 13:
Inhalational anesthetics are largely eliminated via:
Options:
a. The kidneys
b. The skin
c. The lungs
d. The liver

Correct Answer: c. The lungs

Explanation:
Inhalational anesthetics are primarily exhaled unchanged via the lungs. Minimal metabolism occurs in the liver (e.g., halothane).

Question 14:
Methoxyflurane is no longer in use because it is associated with:
Options:
a. Fulminant hepatitis
b. High-output renal failure
c. Seizures
d. Hypoglycemia
e. Cardiac failure

Correct Answer: b. High-output renal failure

Explanation:
Methoxyflurane metabolizes to fluoride ions, causing nephrotoxicity (high-output renal failure). Hepatitis (a) is linked to halothane.

Question 15:
Which one of the following is NOT a factor that could alter the duration of action of atracurium?
Options:
a. Temperature
b. Acid-base status
c. Dose given
d. Age of the patient
e. Duration of the surgery

Correct Answer: e. Duration of the surgery

Explanation:
Atracurium’s duration depends on Hofmann elimination (temperature, pH) and dose (a–c). Surgery duration (e) does not affect its metabolism.

Question 16:
Which one of the following side effects of spinal anesthesia is associated with the use of large-bore spinal needles?
Options:
a. Hypertension
b. Bradycardia
c. Postdural puncture headache (PDPH)
d. Shivering
e. High spinal

Correct Answer: c. Postdural puncture headache (PDPH)

Explanation:
Repeated for emphasis: PDPH is caused by CSF leakage with large needles. Other options are unrelated to needle size.

Question 17:
Severe hypotension associated with high spinal anesthesia is caused primarily by:
Options:
a. Decreased cardiac output secondary to decreased preload
b. Decreased systemic peripheral vascular resistance
c. Decreased cardiac output secondary to bradycardia
d. Decreased cardiac output secondary to reduced myocardial contractility
e. Increased shunting via the metarterioles

Correct Answer: b. Decreased systemic peripheral vascular resistance

Explanation:
High spinal blocks sympathetic tone, causing vasodilation and reduced SVR. Bradycardia (c) may contribute but is secondary.

Question 18:
Antacid premedication in the parturient should be carried out with:
Options:
a. Aluminium hydroxide
b. Magnesium trisilicate
c. Magnesium hydroxide
d. Sodium citrate
e. Metoclopramide

Correct Answer: d. Sodium citrate

Explanation:
Sodium citrate (non-particulate) is preferred in pregnancy to reduce aspiration risk. Particulate antacids (a–c) can cause pneumonitis.

Question 19:
The following are anatomical and physiological risk factors for airway complications during pregnancy EXCEPT:
Options:
a. Weight gain
b. Airway edema
c. Increased heat production
d. Breast engorgement
e. Increased oxygen consumption

Correct Answer: c. Increased heat production

Explanation:
Airway risks include edema (b), weight gain (a), and breast enlargement (d). Heat production (c) does not directly affect airway management.

Question 20:
A normal healthy 3-year-old child was scheduled for emergency surgery. You decide to calculate drug dosages but you do not know the weight. What weight should you use to calculate?
Options:
a. 8 kg
b. 10 kg
c. 12 kg
d. 14 kg
e. 16 kg

Correct Answer: d. 14 kg

Explanation:
For children, weight (kg) = (age × 2) + 8. A 3-year-old: (3 × 2) + 8 = 14 kg.

Question 21:
A 32-year-old pregnant woman with severe asthma needs an emergency cesarean section. Which induction agent would be most appropriate?
Options:
a. Etomidate
b. Midazolam
c. Ketamine
d. Thiopentone
e. Propofol

Correct Answer: c. Ketamine

Explanation:
Ketamine is preferred in asthma (bronchodilator) and hemodynamically unstable patients. Propofol (e) can cause hypotension.

Question 22:
Concerning side effects of propofol:
Options:
a. Causes nausea and vomiting
b. Laryngospasm
c. Bronchospasm
d. Hypertension
e. Pain at site of injection

Correct Answer: e. Pain at site of injection

Explanation:
Propofol causes injection pain (e) but is anti-emetic (a). Bronchospasm (c) is rare; it typically lowers blood pressure (d).

Question 23:
Which muscle relaxant is almost eliminated by the renal system?
Options:
a. Pancuronium
b. Vecuronium
c. Pipecuronium
d. Rocuronium
e. Atracurium

Correct Answer: a. Pancuronium

Explanation:
Pancuronium is 85% renally excreted. Atracurium (e) undergoes Hofmann elimination (independent of renal function).

Question 24:
Which induction agent is most likely to produce bradycardia and asystole?
Options:
a. Propofol
b. Thiopentone
c. Etomidate
d. Ketamine
e. Midazolam

Correct Answer: a. Propofol

Explanation:
Propofol commonly causes bradycardia (vagal stimulation) and can lead to asystole, especially with opioids.

Question 25:
Which disease is associated with increased resistance to neuromuscular blockade with suxamethonium?
Options:
a. Myasthenia gravis
b. Myasthenic syndrome
c. Huntington’s chorea
d. Polymyositis
e. Duchenne muscular dystrophy

Correct Answer: a. Myasthenia gravis

Explanation:
Myasthenia gravis patients have fewer acetylcholine receptors, requiring higher doses of succinylcholine. Dystrophies (e) cause hyperkalemia risk.

Question 26:
Which IV anesthetic drug is converted from water-soluble to lipid-soluble after exposure to the bloodstream?
Options:
a. Propofol
b. Thiopentone
c. Etomidate
d. Ketamine
e. Midazolam

Correct Answer: b. Thiopentone

Explanation:
Thiopentone is water-soluble in the vial but becomes lipid-soluble at physiological pH, enabling rapid CNS penetration.

Question 27:
Patients on propranolol are at increased risk for each of the following EXCEPT:
Options:
a. Blunted response to hypoglycemia
b. Bronchoconstriction
c. Rebound tachycardia after discontinuation
d. Orthostatic hypotension
e. Atrioventricular heart block

Correct Answer: c. Rebound tachycardia after discontinuation

Explanation:
Propranolol (β-blocker) causes bradycardia, not rebound tachycardia (seen with α-blockers). It masks hypoglycemia (a) and worsens asthma (b).

Question 28:
Laudanosine is a metabolite of:
Options:
a. Atracurium
b. D-tubocurarine
c. Vecuronium
d. Pancuronium
e. Rocuronium

Correct Answer: a. Atracurium

Explanation:
Laudanosine is a neurotoxic metabolite of atracurium, especially concerning in renal failure.

Question 29:
The pH of commercially available thiopentone is:
Options:
a. 4.5
b. 5.5
c. 7.4
d. 8.5
e. 10.5

Correct Answer: e. 10.5

Explanation:
Thiopentone is formulated as a highly alkaline solution (pH 10–11) to maintain stability.

Question 30:
In which situation is suxamethonium most likely to cause severe hyperkalemia?
Options:
a. 24 hours after a right hemisphere stroke
b. 14 days after a severe burn injury
c. 24 hours after a mid-thoracic spinal cord transection
d. Acute penetrating abdominal injury
e. Chronic renal failure

Correct Answer: b. 14 days after a severe burn injury

Explanation:
Burns (>48 hours post-injury) and denervation injuries cause upregulation of acetylcholine receptors, leading to life-threatening hyperkalemia with succinylcholine.

Section B: Short Notes & Clinical Scenario

1. Rapid Sequence Induction (RSI) (5 marks)

Definition:
A modified technique for general anesthesia in patients at high risk of aspiration (e.g., full stomach, pregnancy, bowel obstruction).

Key Steps:

1. Preoxygenation: Administer 100% oxygen for 3–5 minutes to denitrogenate the lungs.

2. Induction: Administer a rapid-acting IV anesthetic (e.g., propofol, ketamine) along with a neuromuscular blocking agent (e.g., succinylcholine 1–2 mg/kg or rocuronium 1.2 mg/kg).

3. Cricoid Pressure (Sellick maneuver): Apply pressure to the cricoid cartilage to prevent regurgitation.

4. Intubation: Secure the airway with a cuffed endotracheal tube without prior mask ventilation.

Indications:

• Emergency surgery in non-fasted patients.

• Patients with gastroesophageal reflux disease (GERD).

• Late-stage pregnancy.

Complications:

• Failed intubation.

• Hypotension due to induction agents.

• Laryngospasm if airway reflexes are not fully suppressed.

2. Contraindications to Spinal Anesthesia (5 marks)

Absolute Contraindications:

1. Patient refusal.

2. Infection at the puncture site (risk of meningitis or abscess).

3. Severe coagulopathy (risk of epidural hematoma).

4. Severe hypovolemia or shock (exacerbates hypotension).

5. Increased intracranial pressure (risk of brainstem herniation).

Relative Contraindications:

• Aortic/mitral stenosis (poor tolerance of hypotension).

• Sepsis (risk of spreading infection).

• Preexisting neurological disorders (e.g., multiple sclerosis).

Key Point:

• Platelet count <80,000/mm³ is a common threshold for avoiding spinal anesthesia.

3. Objectives of Premedication (5 marks)

1. Anxiolysis:

• Drug: Midazolam (0.02–0.05 mg/kg IV).

• Purpose: Reduces preoperative anxiety and provides amnesia.

2. Analgesia:

• Drug: Fentanyl (1–2 µg/kg IV).

• Purpose: Provides pain relief and blunts the stress response.

3. Antisialagogue Effect:

• Drug: Glycopyrrolate (0.2–0.4 mg IV).

• Purpose: Reduces salivary secretions.

4. Aspiration Prophylaxis:

• Drug: Sodium citrate (30 mL PO).

• Purpose: Neutralizes gastric acid.

5. Antiemesis:

• Drug: Ondansetron (4–8 mg IV).

• Purpose: Prevents postoperative nausea and vomiting (PONV).

Pediatric Consideration:

• Oral midazolam (0.5 mg/kg) is commonly used for anxiolysis in children.

4. Clinical Manifestations of Local Anesthetic Systemic Toxicity (LAST) (5 marks)

Symptoms (Progressive Stages):

1. Early CNS Effects:

   • Metallic taste, tinnitus, perioral numbness.

   • Agitation, confusion, seizures.

2. Late Cardiovascular Effects:

   • Hypotension, arrhythmias (e.g., ventricular tachycardia).

   • Bradycardia leading to asystole.

Risk Factors:

• High doses of local anesthetic.

• Rapid injection into vascular areas (e.g., intercostal blocks).

Management:

1. Stop the local anesthetic injection immediately.

2. ABCs: Secure airway, administer 100% oxygen.

3. Lipid Emulsion Therapy:

   • Bolus: 1.5 mL/kg of 20% lipid emulsion.

   • Infusion: 0.25 mL/kg/min.

4. Avoid vasopressin and beta-blockers. Use epinephrine (<1 µg/kg) if needed.

Mnemonic: "CNS before CVS" (Neurological symptoms precede cardiovascular collapse).

Clinical Scenario: Anaphylaxis (30 marks)

Scenario:
A 25-year-old male (72 kg) undergoes elective right inguinal hernia repair. Induction includes morphine (7.5 mg IV), thiopentone (400 mg IV), and atracurium (40 mg IV). Five minutes post-induction, SpO₂ drops to 86%, BP falls to 62/28 mmHg, and generalized urticaria appears.

Questions:

1. What is the likely diagnosis?

   • Answer: Anaphylaxis (acute hypotension, bronchospasm, and urticaria post-induction).

2. What chest findings are likely?

   • Answer: Wheezing, prolonged expiration (due to bronchospasm). In severe cases, silent chest may occur.

3. How do you manage this condition?

   • Immediate Steps:

     • Stop all potential triggers (e.g., atracurium).

     • ABCs: 100% oxygen, intubate if necessary.

     • Adrenaline: 50–100 µg IV (0.5–1 mL of 1:10,000 solution). Repeat as needed.

     • Fluids: 1–2 L crystalloid bolus.

   • Secondary Management:

     • Antihistamines: Chlorphenamine (10 mg IV).

     • Corticosteroids: Hydrocortisone (200 mg IV).

     • Bronchodilators: Salbutamol infusion for persistent bronchospasm.

4. What are the most likely precipitating factors?

   • Answer:

     • Muscle relaxants (e.g., atracurium, suxamethonium).

     • Latex (if latex-containing equipment was used).

     • Antibiotics (e.g., penicillin if administered preoperatively).

Investigations:

• Mast cell tryptase levels: Draw at 0, 1–2, and 24 hours post-reaction.

Key Point:

• Adrenaline is the first-line treatment for anaphylaxis. Delayed administration increases mortality risk.

Section A: MCQs

1. Minimum Alveolar Concentration (MAC)

Question: The Minimum Alveolar Concentration (MAC):
Options:
a. It is dependent on lipid solubility.
b. It is a measure of anesthetic depth.
c. It is measured directly in the brain.
d. It is the same for ALL inhalational anesthetics.
e. The higher the MAC value, the more potent the agent is.

Correct Answer: a. It is dependent on lipid solubility.

Explanation:

• MAC is the concentration of an inhalational anesthetic needed to prevent movement in 50% of patients in response to a noxious stimulus.

• Lipid solubility inversely correlates with MAC (more lipid-soluble = lower MAC = more potent).

• Why not others?

  • b. MAC measures potency, not depth (depth depends on multiple factors).

  • c. MAC is measured in alveoli, not the brain.

  • d. MAC varies by agent (e.g., sevoflurane MAC = 2%, desflurane = 6%).

  • e. Higher MAC = less potent (e.g., nitrous oxide MAC = 105%, weak agent).

2. Factors That Reduce MAC Value

Question: The following factors reduce MAC value EXCEPT:
Options:
a. Sedative drugs
b. Pyrexia
c. Hypothermia
d. Pregnancy
e. Opioids

Correct Answer: b. Pyrexia

Explanation:

• Pyrexia (fever) INCREASES MAC due to elevated metabolic demand.

• MAC reducers:

  • Sedatives (a), opioids (e), hypothermia (c), pregnancy (d), age >65, α₂-agonists (e.g., clonidine).

3. Alkane-Based Inhalational Anesthetic

Question: The following is an alkane-based inhalational anesthetic agent:
Options:
a. Halothane
b. Enflurane
c. Isoflurane
d. Sevoflurane

Correct Answer: a. Halothane

Explanation:

• Halothane is a halogenated alkane (CF₃-CHClBr).

• Others are halogenated ethers (e.g., isoflurane: CF₃-CHCl-O-CHF₂).

4. Effects of Inhalational Anesthetics

Question: Inhalational anesthetics can cause all of the following EXCEPT:
Options:
a. Respiratory depression
b. Cardiovascular depression
c. Bronchodilation
d. Bronchoconstriction
e. Reduced cardiac output

Correct Answer: d. Bronchoconstriction

Explanation:

• Volatile agents cause bronchodilation (c) (useful in asthma).

• Exceptions: Desflurane may irritate airways (transient bronchospasm).

• Other effects:

  • Dose-dependent respiratory (a) and cardiovascular (b, e) depression.

5. Inhalational Anesthetic Linked to Hepatitis

Question: Which inhalational anesthetic is associated with fulminant hepatitis?
Options:
a. Isoflurane
b. Halothane
c. Enflurane
d. Sevoflurane
e. Desflurane

Correct Answer: b. Halothane

Explanation:

• Halothane hepatitis is rare (1:35,000) but severe due to immune-mediated hepatotoxicity.

• Risk factors: Repeated exposure, obesity, genetic predisposition.

6. Gaseous Induction in Children

Question: Which agent is suitable for gaseous induction in children?
Options:
a. Isoflurane
b. Desflurane
c. Sevoflurane
d. Nitrous oxide

Correct Answer: c. Sevoflurane

Explanation:

• Sevoflurane is ideal due to non-pungent odor and rapid onset.

• Desflurane (b) irritates airways; nitrous oxide (d) lacks potency alone.

7. Intravenous Anesthetic Agents

Question: The following are intravenous anesthetic agents EXCEPT:
Options:
a. Thiopentone
b. Ketamine
c. Propofol
d. Diazepam
e. Etomidate

Correct Answer: d. Diazepam

Explanation:

• Diazepam is a sedative-hypnotic (benzodiazepine), not used for induction.

• Others: Thiopentone (a), ketamine (b), propofol (c), etomidate (e) are induction agents.

8. Thiopentone Dose

Question: The dose of Thiopentone is:
Options:
a. 1 mg/kg
b. 0.5 mg/kg
c. 5–7 mg/kg
d. 200 mg/kg
e. 50 mg/kg

Correct Answer: c. 5–7 mg/kg

Explanation:

• Induction dose: 3–7 mg/kg IV (lower in elderly/hypovolemia).

9. Ketamine Side Effects

Question: Ketamine can cause all of the following EXCEPT:
Options:
a. Convulsions in epileptics
b. Bradycardia
c. Tachycardia
d. Salivation
e. Hypertension

Correct Answer: b. Bradycardia

Explanation:

• Ketamine increases heart rate (tachycardia, c) and BP (e) via sympathetic stimulation.

• Other effects: Hallucinations, salivation (d), lowers seizure threshold (a).

10. Drugs Crossing Placenta

Question: Which drug can cross the placenta?
Options:
a. Suxamethonium
b. Pancuronium
c. Pethidine
d. Rocuronium
e. Atracurium

Correct Answer: c. Pethidine

Explanation:

• Pethidine (opioid) crosses placenta → neonatal respiratory depression.

• Neuromuscular blockers (a, b, d, e) are ionized → minimal transfer.

11. Clinical Uses of Propofol

Question: Concerning clinical uses of Propofol:
Options:
a. Used for sedation in ICU
b. Used for treatment of bradycardia during anesthesia
c. Analgesic (has poor analgesic properties)
d. Treatment of hypotension
e. Routinely used as an antihypertensive

Correct Answer: a. Used for sedation in ICU

Explanation:

• Propofol is a sedative-hypnotic with no analgesic properties (c).

• ICU sedation: Preferred due to rapid onset/offset and antiemetic effects.

• Not used for: Bradycardia (b), hypotension (d), or hypertension (e) – it worsens these!

12. Induction Agent in Hypovolemic Shock

Question: A patient in hypovolemic shock secondary to ectopic pregnancy. Best induction agent?
Options:
a. Thiopentone
b. Ketamine
c. Propofol
d. Midazolam
e. Pancuronium

Correct Answer: b. Ketamine

Explanation:

• Ketamine maintains BP via sympathetic stimulation (ideal for shock).

• Avoid: Thiopentone (a) and propofol (c) cause hypotension.

13. Amide Local Anesthetic

Question: Which local anesthetic is an amide?
Options:
a. Cocaine
b. Procaine
c. Bupivacaine
d. Chloroprocaine
e. Tetracaine

Correct Answer: c. Bupivacaine

Explanation:

• Amides contain "-caine" with two 'i's in the name (e.g., lidocaine, bupivacaine, ropivacaine).

• Esters: Cocaine (a), procaine (b), chloroprocaine (d), tetracaine (e) – metabolized by plasma cholinesterase.

14. 2% Lignocaine Concentration

Question: 2% lignocaine means:
Options:
a. 2 mg/mL
b. 20 mg/mL
c. 200 mg/mL
d. 0.2 mg/mL
e. 2 g/mL

Correct Answer: b. 20 mg/mL

Explanation:

• Percentage (%) = grams per 100 mL.

• 2% = 2 g/100 mL = 20 mg/mL.

15. Bupivacaine Properties

Question: Which is not true about bupivacaine?
Options:
a. Used for spinal anesthesia
b. Local infiltration
c. Used for epidural anesthesia
d. Used for nerve blocks
e. Used for treatment of arrhythmias

Correct Answer: e. Used for treatment of arrhythmias

Explanation:

• Lidocaine (not bupivacaine) is a Class IB antiarrhythmic.

• Bupivacaine is cardiotoxic if given IV (risk of ventricular arrhythmias).

16. Synthetic Opioids

Question: The following are synthetic opioids EXCEPT:
Options:
a. Morphine
b. Fentanyl
c. Pethidine
d. Alfentanil
e. Remifentanil

Correct Answer: a. Morphine

Explanation:

• Morphine is a natural opioid (derived from opium).

• Synthetics: Fentanyl (b), pethidine (c), alfentanil (d), remifentanil (e).

17. Opioid Properties

Question: The following is NOT a property of opioids:
Options:
a. Respiratory stimulation
b. Respiratory depression
c. Nausea and vomiting
d. Histamine release (causing urticaria)
e. Dysphoria

Correct Answer: a. Respiratory stimulation

Explanation:

• Opioids cause dose-dependent respiratory depression (b).

• Other effects: Nausea (c), histamine release (d), dysphoria (e).

18. Depolarizing Muscle Relaxant

Question: The following is a depolarizing muscle relaxant:
Options:
a. Atracurium
b. Pancuronium
c. Suxamethonium
d. Vecuronium
e. Cisatracurium

Correct Answer: c. Suxamethonium

Explanation:

• Suxamethonium is the only depolarizing NMBA (binds Ach receptors → persistent depolarization).

• Others (a, b, d, e) are non-depolarizing (competitive antagonists).

19. Side Effects of Suxamethonium

Question: The following are side effects of suxamethonium EXCEPT:
Options:
a. Hyperkalemia
b. Malignant hyperthermia
c. Bradycardia
d. Prolonged paralysis
e. Myalgia

Correct Answer: d. Prolonged paralysis

Explanation:

• Suxamethonium has ultra-short duration (5–10 mins) due to rapid hydrolysis by plasma cholinesterase.

• Side effects: Hyperkalemia (a), MH (b), bradycardia (c), myalgia (e).

20. Anaphylaxis Management

Question: Immediate management of anaphylaxis includes all EXCEPT:
Options:
a. Adrenaline (epinephrine) IV
b. Stop all potential triggers
c. Administer 100% oxygen
d. Give IV hydrocortisone first
e. Fluid resuscitation

Correct Answer: d. Give IV hydrocortisone first

Explanation:

• Adrenaline (a) is first-line for anaphylaxis (α-1 vasoconstriction, β-2 bronchodilation).

• Hydrocortisone is secondary (prevents biphasic reactions).

Section A: MCQs

1. Ideal Properties of Inhalational Anesthetics

Question: The following are ideal properties EXCEPT:
Options:
a. Pleasant odor
b. High blood/gas solubility
c. Flammable and explosive
d. Non-toxic and non-allergenic

Correct Answer: c. Flammable and explosive
Explanation:

• Safe inhalational agents are non-flammable. Ideal properties include low blood/gas solubility (b) for rapid onset, non-toxicity (d), and pleasant odor (a) for patient comfort.

2. Minimum Alveolar Concentration (MAC)

Question: The MAC:
Options:
a. Depends on water solubility
b. Measures anesthetic potency
c. Measured directly in the brain
d. Same for all inhalational agents
e. Higher MAC = more potent

Correct Answer: b. Measures anesthetic potency
Explanation:

• MAC is the alveolar concentration preventing movement in 50% of patients. Lower MAC = higher potency (e.g., halothane MAC 0.75% vs. nitrous oxide 105%).

• Incorrect: MAC depends on lipid solubility (a), is measured in alveoli (c), and varies by agent (d).

3. Factors Increasing MAC

Question: The following increase MAC EXCEPT:
Options:
a. Amphetamines
b. Pyrexia
c. Hypothermia
d. Chronic alcohol abuse
e. Hyperthermia

Correct Answer: c. Hypothermia
Explanation:

• Hypothermia decreases MAC. Increase MAC: Hyperthermia (e), amphetamines (a), chronic alcohol abuse (d).

4. Alkane-Based Inhalational Anesthetic

Question: Identify the alkane-based agent:
Options:
a. Halothane
b. Enflurane
c. Isoflurane
d. Sevoflurane
e. Desflurane

Correct Answer: a. Halothane
Explanation:

• Halothane is a halogenated alkane (CF₃-CHClBr). Others are ethers (e.g., isoflurane: CF₃-CHCl-O-CHF₂).

5. Isoflurane Effects

Question: Isoflurane causes all EXCEPT:
Options:
a. Respiratory depression
b. Cardiovascular depression
c. Bronchodilation
d. Bronchoconstriction
e. Reduced cardiac output

Correct Answer: d. Bronchoconstriction
Explanation:

• Isoflurane causes bronchodilation (c). Desflurane may irritate airways (transient bronchospasm).

6. Inhalational Anesthetic Linked to Hepatitis

Question: Associated with fulminant hepatitis:
Options:
a. Isoflurane
b. Desflurane
c. Sevoflurane
d. Nitrous oxide

Correct Answer: None listed (Halothane is correct)
Explanation:

• Halothane causes immune-mediated hepatitis (1:35,000). Error: Halothane not listed in options.

7. Intravenous Anesthetic Agents

Question: The following are IV anesthetics EXCEPT:
Options:
a. Thiopentone
b. Ketamine
c. Propofol
d. Diazepam
e. Etomidate

Correct Answer: d. Diazepam
Explanation:

• Diazepam is a sedative-hypnotic (benzodiazepine), not used for induction.

8. Thiopentone Dose

Question: The dose of thiopentone is:
Options:
a. 1 mg/kg
b. 0.5 mg/kg
c. 5–7 mg/kg
d. 200 mg/kg
e. 50 mg/kg

Correct Answer: c. 5–7 mg/kg
Explanation:

• Standard induction dose: 3–7 mg/kg IV (lower in elderly/hypovolemia).

9. Ketamine Side Effects

Question: Ketamine causes all EXCEPT:
Options:
a. Convulsions in epileptics
b. Bradycardia
c. Tachycardia
d. Salivation
e. Hypertension

Correct Answer: b. Bradycardia
Explanation:

• Ketamine increases HR/BP (c, e) via sympathetic stimulation. Bradycardia is rare (vagal stimulation).

10. Placental Drug Transfer

Question: Can cross the placenta:
Options:
a. Suxamethonium
b. Pancuronium
c. Pethidine
d. Rocuronium
e. Atracurium

Correct Answer: c. Pethidine
Explanation:

• Pethidine (opioid) crosses placenta → neonatal respiratory depression. NMBAs (a, b, d, e) are ionized → minimal transfer.

11. Propofol Clinical Uses

Question: Concerning propofol:
Options:
a. ICU sedation
b. Treats bradycardia
c. Analgesic
d. Treats hypotension
e. Antihypertensive

Correct Answer: a. ICU sedation
Explanation:

• Propofol is not analgesic (c) and causes hypotension (d). Used for sedation (a) and induction.

12. Induction in Hypovolemic Pregnancy

Question: Best induction agent for hypovolemic pregnancy:
Options:
a. Thiopentone
b. Ketamine
c. Propofol
d. Midazolam
e. Pancuronium

Correct Answer: b. Ketamine
Explanation:

• Ketamine maintains BP via sympathetic stimulation. Avoid propofol (c)/thiopentone (a) (hypotension).

13. Amide Local Anesthetic

Question: Identify the amide local anesthetic:
Options:
a. Cocaine
b. Procaine
c. Bupivacaine
d. Chloroprocaine
e. Tetracaine

Correct Answer: c. Bupivacaine
Explanation:

• Amides contain "i" in the name (e.g., lidocaine, bupivacaine). Esters: Cocaine (a), procaine (b).

14. Maximum Safe Dose of Lignocaine

Question: Max safe dose of plain lignocaine:
Options:
a. 5 mg/kg
b. 7 mg/kg
c. 1 mg/kg
d. 0.5 mg/kg
e. 0.7 mg/kg

Correct Answer: b. 7 mg/kg
Explanation:

• Plain lignocaine: 3 mg/kg (with adrenaline: 7 mg/kg). Question likely refers to plain.

15. Bupivacaine Misconception

Question: Not true about bupivacaine:
Options:
a. Spinal anesthesia
b. Local infiltration
c. Epidural anesthesia
d. Nerve blocks
e. Treats arrhythmias

Correct Answer: e. Treats arrhythmias
Explanation:

• Lidocaine is a Class IB antiarrhythmic. Bupivacaine is cardiotoxic if given IV.

16. Synthetic Opioids

Question: Synthetic opioid EXCEPT:
Options:
a. Morphine
b. Fentanyl
c. Pethidine
d. Alfentanil
e. Remifentanil

Correct Answer: a. Morphine
Explanation:

• Morphine is a natural opioid. Others (b-e) are synthetic.

17. Opioid Properties

Question: Not a property of opioids:
Options:
a. Respiratory stimulation
b. Respiratory depression
c. Nausea/vomiting
d. Histamine release
e. Dysphoria

Correct Answer: a. Respiratory stimulation
Explanation:

• Opioids cause dose-dependent respiratory depression (b).

18. Depolarizing Muscle Relaxant

Question: Depolarizing NMBA:
Options:
a. Atracurium
b. Pancuronium
c. Suxamethonium
d. Vecuronium
e. Cisatracurium

Correct Answer: c. Suxamethonium
Explanation:

• Suxamethonium binds Ach receptors → persistent depolarization. Others are non-depolarizing.

19. Suxamethonium Side Effects

Question: Side effects EXCEPT:
Options:
a. Bradycardia
b. Myalgia
c. Convulsions
d. Increased intraocular pressure
e. Hyperkalemia

Correct Answer: c. Convulsions
Explanation:

• Suxamethonium causes fasciculations (not seizures), hyperkalemia (e), and myalgia (b).

Section B: Long Essays

1. Propofol

a. Classification: Alkylphenol IV anesthetic.
b. Mechanism: Potentiates GABA_A receptors.
c. Pharmacokinetics: Rapid onset (30 sec), hepatic metabolism.
d. Uses: Induction, ICU sedation, procedural sedation.
e. Side Effects: Hypotension, apnea, pain on injection.
f. Contraindications: Egg/soy allergy, propofol infusion syndrome.

2. Ketamine

a. Class: Dissociative anesthetic.
b. Mechanism: NMDA receptor antagonist.
c. Metabolism: Hepatic to norketamine (active).
d. Effects: Analgesia, bronchodilation, sympathomimetic.
e. Contraindications: Hypertension, elevated ICP.
f. Dose: 1–2 mg/kg IV induction.

3. Rapid Sequence Induction (RSI)

• Steps: Preoxygenation → induction agent + succinylcholine/rocuronium → cricoid pressure → intubation.

• Indications: Full stomach, bowel obstruction.

4. Suxamethonium

• Depolarizing NMBA: Rapid onset (30 sec), short duration (5–10 min).

• Side Effects: Hyperkalemia, myalgia, malignant hyperthermia.

5. Spinal Anesthesia

• Indications: C-section, lower limb surgery.

• Complications: Hypotension, PDPH, high spinal block.