Anesthesia for Congenital Heart Disease — MCQs
Induction agent of choice in a child with cyanotic heart disease is
In which clinical scenario would you find a patient requiring the vital signs assessment technique shown in the image?
Anesthesia of choice for induction in children among the following is:
The commonest type of congenital heart disease is –
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 child with Tetralogy of Fallot develops worsening cyanosis and fainting spells. Which immediate intervention is recommended?
What is the initial palliative treatment for Tetralogy of Fallot?
A pregnant woman is diagnosed with Graves' disease. The most appropriate therapy for her would be:
A 5 year old boy suffering from Duchenne muscular dystrophy has to undergo tendon lengthening procedure. The most appropriate anaesthetic would be –
Which of the following is a PGE1 analogue used in medical treatments?
Anesthesia for Congenital Heart Disease Indian Medical PG Practice Questions and MCQs
Question 1: Induction agent of choice in a child with cyanotic heart disease is
- A. Thiopentone
- B. Ketamine (Correct Answer)
- C. Halothane
- D. Midazolam
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.
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)
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.
Question 3: Anesthesia of choice for induction in children among the following is:
- A. Isoflurane
- B. Sevoflurane (Correct Answer)
- C. Halothane
- D. Desflurane
Explanation: ***Sevoflurane*** - **Sevoflurane** is the anesthetic of choice for induction in children due to its **low pungency**, which reduces the likelihood of coughing and laryngospasm. - It has a relatively **rapid onset of action** and allows for a smooth, inhalation induction, making it well-tolerated by pediatric patients. *Isoflurane* - **Isoflurane** has a **pungent odor** and is known to cause a higher incidence of airway irritation, coughing, and breath-holding, making it less suitable for mask induction in children. - It also has a **slower onset** compared to sevoflurane, which can prolong the induction process. *Halothane* - **Halothane** was previously used for pediatric induction but is largely uncommonly used today due to its association with **hepatotoxicity** (halothane hepatitis) and cardiac arrhythmias. - While it has a relatively pleasant odor, its significant side effect profile makes it a less desirable option now. *Desflurane* - **Desflurane** is very **pungent** and frequently causes airway irritation, coughing, and laryngospasm, making it unsuitable for mask induction in children. - It also has a **low potency** compared to other volatile anesthetics, requiring higher concentrations that can exacerbate airway complications.
Question 4: The commonest type of congenital heart disease is –
- A. ASD
- B. PDA
- C. TOF
- D. VSD (Correct Answer)
Explanation: ***VSD*** - **Ventricular Septal Defect (VSD)** is the most common type of **congenital heart disease**, accounting for approximately 25-30% of all congenital heart defects. - It involves a hole in the septum separating the **ventricles**, leading to a **left-to-right shunt** of blood. *ASD* - **Atrial Septal Defects (ASDs)** are common but less frequent than VSDs, typically accounting for about 10% of congenital heart defects. - ASDs involve a hole in the septum separating the **atria**, also causing a **left-to-right shunt**. *PDA* - **Patent Ductus Arteriosus (PDA)** is another common congenital heart defect, but it is less prevalent than VSD, accounting for around 5-10% of cases. - PDA is the persistence of the fetal **ductus arteriosus**, allowing blood to flow from the **aorta to the pulmonary artery**. *TOF* - **Tetralogy of Fallot (TOF)** is a complex cyanotic congenital heart defect, representing about 5-7% of all congenital heart diseases. - It is characterized by four distinct anomalies: **pulmonary stenosis**, **ventricular septal defect**, **overriding aorta**, and **right ventricular hypertrophy**.
Question 5: 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
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.
Question 6: 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)
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.
Question 7: 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
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.
Question 8: 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)
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.
Question 9: 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
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.
Question 10: Which of the following is a PGE1 analogue used in medical treatments?
- A. Carboprost
- B. Alprostadil (Correct Answer)
- C. Epoprostenol
- D. Dinoprostone
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.
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