Anesthesia for Congenital Heart Disease Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Anesthesia for Congenital Heart Disease. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 1: Induction agent of choice in a child with cyanotic heart disease is
- A. Thiopentone
- B. Ketamine (Correct Answer)
- C. Halothane
- D. Midazolam
Anesthesia for Congenital Heart Disease Explanation: ***Ketamine***
- **Ketamine** is preferred in cyanotic heart disease because it generally maintains or even **increases systemic vascular resistance** and **blood pressure**, which helps maintain systemic-pulmonary shunting and reduces right-to-left shunting.
- It also has a **sympathomimetic effect**, supporting myocardial contractility and heart rate, which is beneficial in patients with compromised cardiac function.
*Thiopentone*
- **Thiopentone** can cause **myocardial depression** and **vasodilation**, leading to a decrease in systemic vascular resistance.
- This reduction in SVR can exacerbate **right-to-left shunting** in cyanotic heart disease, worsening hypoxemia.
*Halothane*
- **Halothane** is a potent **myocardial depressant** and causes significant **peripheral vasodilation**, leading to decreased blood pressure and systemic vascular resistance.
- These effects can lead to a severe decrease in **pulmonary blood flow** and an increase in **right-to-left shunting**, worsening cyanosis and hypoxemia.
*Midazolam*
- **Midazolam** is a benzodiazepine primarily used for **sedation** and anxiolysis, not as a primary induction agent in critically ill children.
- While it has minimal effects on cardiac output at typical doses, it lacks the favorable hemodynamic profile of ketamine for maintaining **organ perfusion** and preventing increased right-to-left shunting in cyanotic heart disease.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 2: In which clinical scenario would you find a patient requiring the vital signs assessment technique shown in the image?
- A. Pulse absent, breath present
- B. Pulse and breath both not present
- C. Pulse and breath present
- D. Pulse present, breath absent (Correct Answer)
Anesthesia for Congenital Heart Disease Explanation: ***Pulse present, breath absent***
- The image depicts a **mouth-to-mouth resuscitation** technique, specifically rescue breaths being administered by one person to another.
- This technique is applied when a person has a **detectable pulse** but is **not breathing** or is only gasping, indicating respiratory arrest while the heart is still circulating blood.
*Pulse absent, breath present*
- This scenario would represent **cardiac arrest** where the heart has stopped, but the person is still attempting to breathe. This is a rare, transient state.
- In such a case, the primary intervention would be **chest compressions**, not just rescue breathing, as circulation is the immediate priority.
*Pulse and breath both not present*
- This describes **cardiopulmonary arrest (CPA)**, where both the heart and lungs have ceased functioning.
- The appropriate intervention is **cardiopulmonary resuscitation (CPR)**, which involves a combination of **chest compressions and rescue breaths (30:2 ratio)**, not just rescue breaths alone.
*Pulse and breath present*
- If both vital signs are present, the person is **conscious and breathing adequately**, or unconscious but breathing normally.
- No advanced respiratory intervention like mouth-to-mouth resuscitation is needed; the priority would be maintaining their airway and monitoring their condition.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 3: A 6 month old child is suffering from patent ductus arteriosus (PDA) with congestive cardiac failure. Ligation of ductus arteriosus was decided for surgical management. The most appropriate inhalational anaesthetic agent of choice with minimal haemodynamic alteration for induction of anaesthesia is –
- A. Sevoflurane (Correct Answer)
- B. Isoflurane
- C. Enflurane
- D. Halothane
Anesthesia for Congenital Heart Disease Explanation: ***Sevoflurane***
- **Sevoflurane** is the preferred inhalational anesthetic for induction in pediatric patients, especially those with cardiovascular compromise, due to its **less pungent odor**, leading to smoother induction and minimal airway irritation.
- It maintains **hemodynamic stability** better than other volatile agents at equipotent doses, making it suitable for children with congenital heart defects like PDA.
*Isoflurane*
- **Isoflurane** has a more **pungent odor** than sevoflurane, making it less suitable for mask induction in pediatric patients due to potential airway irritation and resistance.
- While it offers good hemodynamic stability, its higher pungency can lead to coughing or laryngospasm during induction, which is undesirable in a child with cardiac compromise.
*Enflurane*
- **Enflurane** is now largely replaced by newer agents like sevoflurane and isoflurane due to its potential to cause **seizures** and myocardial depression, especially at higher concentrations.
- It also carries a risk of inducing **nephrotoxicity** due to fluoride metabolism and is associated with more significant hemodynamic alterations compared to sevoflurane.
*Halothane*
- **Halothane** is associated with significant **myocardial depression**, leading to reduced cardiac output and hypotension, which is particularly detrimental in a child with congestive cardiac failure due to PDA.
- It also has a risk of causing **halothane hepatitis**, a rare but severe liver toxicity, making it a less safe option compared to modern inhalational agents.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 4: A child with Tetralogy of Fallot develops worsening cyanosis and fainting spells. Which immediate intervention is recommended?
- A. Morphine
- B. Oxygen therapy
- C. IV fluids
- D. Knee-chest position (Correct Answer)
Anesthesia for Congenital Heart Disease Explanation: ***Knee-chest position***
- The **knee-chest position** increases **systemic vascular resistance (SVR)**, which helps to reduce the right-to-left shunting of deoxygenated blood through the ventricular septal defect (VSD) in Tetralogy of Fallot.
- This maneuver effectively alleviates **hypercyanotic spells** (tet spells) by increasing pulmonary blood flow and improving oxygenation.
*Morphine*
- While morphine can be used to sedate and reduce infundibular spasm during a tet spell, it is typically administered *after* initial attempts to increase SVR, such as the knee-chest position.
- Its primary role is to reduce anxiety and calm the child, which can indirectly help, but it's not the immediate mechanical intervention of choice.
*Oxygen therapy*
- **Oxygen therapy** can be beneficial by increasing the partial pressure of oxygen in the blood, which may help to alleviate cyanosis.
- However, in a severe tet spell, the primary issue is reduced pulmonary blood flow due to an outflow obstruction and right-to-left shunting, so simply providing oxygen without addressing the shunting is often insufficient as an immediate, stand-alone intervention.
*IV fluids*
- **IV fluids** are important for maintaining adequate **preload** and preventing dehydration, especially if the child is hyperpneic or agitated.
- While supportive, IV fluids do not directly address the underlying pathophysiology of a tet spell, which involves a dynamic right ventricular outflow tract obstruction and right-to-left shunting.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 5: What is the initial palliative treatment for Tetralogy of Fallot?
- A. Modified BT shunt (Correct Answer)
- B. Waterston shunt
- C. BT shunt
- D. Potts shunt operation
Anesthesia for Congenital Heart Disease Explanation: **Modified BT shunt**
- The **Modified Blalock-Taussig (BT) shunt** is the initial palliative treatment for Tetralogy of Fallot, providing a reliable source of **pulmonary blood flow** in infants with severe cyanosis.
- It involves connecting a **systemic artery** (subclavian or brachiocephalic artery) to the **pulmonary artery** using an interposition graft, increasing blood flow to the lungs.
*Waterston shunt*
- The **Waterston shunt** connects the **ascending aorta** to the **right pulmonary artery**.
- It has a higher incidence of **pulmonary artery distortion** and pulmonary hypertension, making it less favorable than the modified BT shunt.
*BT shunt*
- The classic **Blalock-Taussig shunt** involves a direct anastomosis between the subclavian artery and the pulmonary artery.
- While effective, the **Modified BT shunt** using a graft is generally preferred due to less vascular injury and improved long-term patency.
*Potts shunt operation*
- The **Potts shunt** connects the **descending aorta** to the **left pulmonary artery**.
- Similar to the Waterston shunt, it carries a higher risk of **pulmonary artery distortion** and is rarely used today.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 6: A pregnant woman is diagnosed with Graves' disease. The most appropriate therapy for her would be:
- A. Radioiodine therapy
- B. Total thyroidectomy
- C. Carbimazole parenteral
- D. Propylthiouracil oral (Correct Answer)
Anesthesia for Congenital Heart Disease Explanation:
***Propylthiouracil oral***
- **Propylthiouracil (PTU)** is the preferred antithyroid drug during the **first trimester** of pregnancy due to a lower risk of teratogenicity compared to methimazole/carbimazole [1].
- It works by inhibiting both the synthesis of thyroid hormones and the peripheral conversion of **T4 to T3**.
*Radioiodine therapy*
- **Radioactive iodine** is absolutely contraindicated in pregnancy as it can cross the placenta and cause **fetal hypothyroidism or athyreosis**.
- It leads to permanent destruction of the thyroid gland and is not suitable for a temporary condition in a pregnant woman.
*Total thyroidectomy*
- While thyroidectomy can be considered for Graves' disease in pregnancy, it is generally reserved for cases where antithyroid drugs are not tolerated or ineffective, or for very large goiters causing compressive symptoms.
- It carries risks associated with **surgery and anesthesia** during pregnancy, and requires **lifelong thyroid hormone replacement**.
*Carbimazole parenteral*
- **Carbimazole** (which is metabolized to methimazole) is generally avoided in the **first trimester** due to an increased risk of teratogenicity, particularly **aplasia cutis**, omphalocele, and choanal atresia [1].
- While it can be used in the second and third trimesters, **PTU is preferred in the first trimester**, and carbimazole is not typically administered parenterally.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 7: A 5 year old boy suffering from Duchenne muscular dystrophy has to undergo tendon lengthening procedure. The most appropriate anaesthetic would be –
- A. Induction with inhalation sevoflurane; maintenance with isoflurane and vecuronium
- B. Total intravenous anesthesia (TIVA) with propofol and remifentanil (Correct Answer)
- C. Induction with intravenous propofol and N2O; TIVA maintenance with propofol
- D. Induction with intravenous thiopentone; maintenance with sevoflurane and non-depolarizing muscle relaxants
Anesthesia for Congenital Heart Disease Explanation: ***Total intravenous anesthesia (TIVA) with propofol and remifentanil***
- **Duchenne muscular dystrophy (DMD)** patients are highly susceptible to **malignant hyperthermia** and rhabdomyolysis when exposed to volatile anesthetics (e.g., sevoflurane, isoflurane) and succinylcholine. TIVA avoids these triggers.
- **Propofol** and **remifentanil** are suitable anesthetic agents for TIVA in DMD patients, providing stable anesthesia without triggering adverse muscle reactions.
*Induction with inhalation sevoflurane; maintenance with isoflurane and vecuronium*
- **Sevoflurane** and **isoflurane** are volatile anesthetic agents that can trigger **malignant hyperthermia** and severe rhabdomyolysis in patients with DMD due to their muscle pathology.
- While vecuronium is a non-depolarizing muscle relaxant that is generally safe in DMD, the use of volatile agents makes this regimen inappropriate.
*Induction with intravenous propofol and N2O; TIVA maintenance with propofol*
- **Nitrous oxide (N2O)**, while not a direct trigger for malignant hyperthermia itself, is often used in conjunction with volatile anesthetics and does not significantly mitigate the risks associated with them in DMD patients.
- Although propofol for induction and TIVA maintenance is appropriate, the inclusion of N2O does not improve safety in the context of DMD, and concerns about potential interactions or masking early signs of complications might arise.
*Induction with intravenous thiopentone; maintenance with sevoflurane and non-depolarizing muscle relaxants*
- **Thiopentone** (thiopental) is an intravenous anesthetic that is generally safe for induction in DMD patients.
- However, **sevoflurane** is a volatile anesthetic that is contraindicated in DMD due to the risk of triggering **malignant hyperthermia** and severe rhabdomyolysis.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 8: Which of the following is a PGE1 analogue used in medical treatments?
- A. Carboprost
- B. Alprostadil (Correct Answer)
- C. Epoprostenol
- D. Dinoprostone
Anesthesia for Congenital Heart Disease Explanation: ***Alprostadil***
- **Alprostadil** is a synthetic **prostaglandin E1 (PGE1)** analogue.
- It is used in neonates to maintain the **patency of the patent ductus arteriosus** and in adults for the treatment of **erectile dysfunction**.
*Carboprost*
- **Carboprost** is a synthetic analogue of **prostaglandin F2 alpha (PGF2α)**.
- It is primarily used to manage **postpartum hemorrhage** due to its potent uterotonic effects.
*Epoprostenol*
- **Epoprostenol** is a synthetic analogue of **prostacyclin (PGI2)**.
- It is known for its potent **vasodilatory** and **antiplatelet** properties, making it useful in treating **pulmonary arterial hypertension**.
*Dinoprostone*
- **Dinoprostone** is a synthetic form of **prostaglandin E2 (PGE2)**.
- It is used to **induce labor** or **cervical ripening** due to its role in uterine contractions and cervical dilation.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 9: Which of the following is most cardio depressant
- A. Sevoflurane
- B. Halothane (Correct Answer)
- C. Isoflurane
- D. Desflurane
Anesthesia for Congenital Heart Disease Explanation: ***Halothane***
- **Halothane** is known for causing significant **myocardial depression** by directly reducing myocardial contractility and stroke volume.
- It also **sensitizes the myocardium to catecholamines**, increasing the risk of arrhythmias.
*Sevoflurane*
- **Sevoflurane** causes less **myocardial depression** and is often preferred in patients with compromised cardiac function.
- Its effects on heart rate and blood pressure are generally moderate compared to halothane.
*Isoflurane*
- **Isoflurane** can cause **systemic vasodilation** and a dose-dependent decrease in blood pressure but is generally less cardio-depressant than halothane.
- It maintains **cardiac output** better than halothane, sometimes increasing heart rate to compensate for vasodilation.
*Desflurane*
- **Desflurane** typically causes a **lesser degree of myocardial depression** and tends to preserve cardiac output.
- It can, however, lead to transient increases in heart rate and blood pressure upon rapid increases in concentration due to **sympathetic stimulation**.
Anesthesia for Congenital Heart Disease Indian Medical PG Question 10: Which of the following anesthetic induction agents should be avoided in a 4-year-old boy with temporal lobe epilepsy?
- A. Thiopental
- B. Halothane
- C. Ketamine (Correct Answer)
- D. All of the above
Anesthesia for Congenital Heart Disease Explanation: **Explanation:**
The correct answer is **Ketamine**.
**1. Why Ketamine is avoided:**
Ketamine is a phencyclidine derivative that acts as an NMDA receptor antagonist. While it provides excellent analgesia and dissociation, it is known to stimulate the central nervous system. In patients with a history of epilepsy, Ketamine can lower the seizure threshold and induce **epileptiform activity** on an EEG. Specifically, it can trigger seizure foci in the cortical and subcortical areas, making it contraindicated (or used with extreme caution) in patients with poorly controlled epilepsy or temporal lobe lesions.
**2. Analysis of Incorrect Options:**
* **Thiopental:** This is a barbiturate and is actually considered an **anticonvulsant**. It is often used to terminate status epilepticus. It increases the seizure threshold and is safe (even protective) for patients with epilepsy.
* **Halothane:** While potent inhalational agents can occasionally show EEG changes at very high concentrations, Halothane does not have significant pro-convulsant properties. It is generally safe for induction in epileptic children, though Sevoflurane is more commonly used in modern practice.
**3. NEET-PG High-Yield Pearls:**
* **Pro-convulsant Agents:** Ketamine, Methohexital (often used to *induce* seizures during ECT), and Etomidate (can activate seizure foci).
* **Meperidine (Pethidine):** Its metabolite, **normeperidine**, is a potent CNS stimulant and can cause seizures, especially in renal failure.
* **Sevoflurane Paradox:** At high concentrations (>2 MAC) and with hypocapnia, Sevoflurane can show epileptiform patterns on EEG, but it is clinically used safely in most pediatric cases.
* **Drug of Choice for Status Epilepticus (Anesthesia):** Thiopental or Propofol.
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