Pediatric Anesthesia Practice Questions

Q: Why is there a higher incidence of endobronchial intubation in pediatric patients?

Short trachea. ### Explanation **1. Why "Short Trachea" is Correct:** The primary anatomical reason for the high incidence of accidental endobronchial intubation in pediatric patients is the **short length of the trachea**. At birth, the trachea is approximately **4–5 cm** long, increasing to about **7 cm** by 18 months of age. Because the distance between the vocal cords and the carina is so small, even a slight downward displacement of the endotracheal tube (ETT)—caused by neck flexion or surgical manipulation—can easily result in the tube entering the right mainstem bronchus. **2. Analysis of Incorrect Options:** * **Option B (Longer pediatric ETT):** This is incorrect. Pediatric tubes are manufactured in various lengths, and the clinician selects the length based on the child’s age or height (using formulas like *Age/2 + 12 cm*). The length of the tube itself is not the anatomical cause; rather, it is the **incorrect positioning or migration** of the tube within a limited anatomical space. * **Option C & D:** These are incorrect as the anatomical "short trachea" is the definitive physiological predisposition. **3. Clinical Pearls for NEET-PG:** * **The "Rule of Movement":** In pediatrics, **flexion** of the neck moves the ETT deeper (towards the carina), potentially causing endobronchial intubation. **Extension** of the neck moves the ETT cephalad (towards the mouth), potentially causing accidental extubation. ("The tube follows the nose"). * **Narrowest Part:** Historically, the **cricoid cartilage** was considered the narrowest part of the pediatric airway (funnel-shaped). However, recent MRI studies suggest it may be the **glottis** (cylindrical), though "cricoid" remains a common exam answer. * **Mainstem Anatomy:** Unlike adults, the angles of the right and left mainstem bronchi are more symmetrical in infants (approx. 30-35°), though the right side remains a more frequent site for accidental intubation.

Q: What is the anesthetic of choice in a child with cyanotic heart disease?

Ketamine. **Explanation:** The primary goal in the anesthetic management of cyanotic heart disease (e.g., Tetralogy of Fallot) is to prevent or minimize **right-to-left (R-L) shunting**. R-L shunting is exacerbated by a decrease in **Systemic Vascular Resistance (SVR)** or an increase in Pulmonary Vascular Resistance (PVR). **Why Ketamine is the Correct Choice:** Ketamine is the induction agent of choice because it stimulates the sympathetic nervous system, leading to an **increase in SVR**. By maintaining or increasing systemic pressure relative to pulmonary pressure, Ketamine helps reduce the R-L shunt, thereby maintaining or improving arterial oxygen saturation. It also maintains functional residual capacity and has minimal impact on airway resistance. **Why Other Options are Incorrect:** * **Propofol & Thiopentone:** Both are potent vasodilators that significantly **decrease SVR**. A drop in SVR worsens the R-L shunt, leading to a "Tet spell" or profound cyanosis and cardiovascular collapse. * **Sevoflurane:** While commonly used for pediatric induction, volatile anesthetics cause dose-dependent vasodilation (decreasing SVR) and can depress myocardial contractility, which is less ideal than Ketamine in unstable cyanotic patients. **High-Yield Clinical Pearls for NEET-PG:** * **The Goal:** Maintain high SVR and low PVR. * **Tetralogy of Fallot (TOF):** Avoid drugs that cause histamine release (like Morphine or Atracurium) as they can drop SVR. * **Premedication:** Adequate sedation is crucial to prevent crying/struggling, which increases PVR and triggers cyanotic spells. * **Fluid Status:** Maintain adequate preload; dehydration worsens shunting.

Q: The size of endotracheal tube in a child < 6 years old is calculated using which formula?

(Age ÷ 4) + 3.5. ***(Age ÷ 4) + 3.5*** - This formula is for calculating the appropriate **uncuffed endotracheal tube (ETT) size** for children 1-10 years old. - For children less than 6 years old, an **uncuffed ETT** is often preferred to reduce the risk of subglottic stenosis. *(Age ÷ 4) - 4.5* - This formula is incorrect for determining ETT size in children. - Subtracting 4.5 would result in an ETT size that is usually too small for the child. *(Age ÷ 4) + 4.5* - This formula is incorrect for determining ETT size in children. - Adding 4.5 would result in an ETT size that is usually too large, increasing the risk of tracheal injury. *(Age ÷ 4) + 2.5* - This formula is incorrect for determining ETT size in children. - Adding 2.5 would result in an ETT size that may be too small or too snug, potentially leading to increased work of breathing or airway obstruction.

Q: 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 –

Sevoflurane. ***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.

Q: A two month old infant has undergone a major surgical procedure. Regarding postoperative pain relief which one of the following is recommended:

Intravenous narcotic infusion in lower dosage. ***Intravenous narcotic infusion in lower dosage*** - **Intravenous narcotic infusion** provides continuous pain relief and allows for careful titration of the dose, which is crucial in infants due to their developing metabolism and increased sensitivity to opioids. - Lower dosages are recommended because infants have a **reduced capacity for drug metabolism** and excretion, making them more susceptible to side effects like respiratory depression. *Spinal narcotics intrathecal route* - While effective, the **intrathecal route** carries risks such as neurotoxicity and spinal cord injury, which are particularly concerning in infants due to their small size and developing neural structures. - The **pharmacokinetics** of intrathecal narcotics can also be unpredictable in infants, leading to potential for delayed respiratory depression. *Only paracetamol suppository is adequate* - For **major surgical procedures**, a single agent like **paracetamol** is typically insufficient to manage severe postoperative pain effectively. - While paracetamol is a useful adjunct, it lacks the potent analgesic effects of opioids needed for comprehensive pain control after significant surgery. *No medication is needed as infant does not feel pain after surgery due to immaturity of nervous system* - This statement is **incorrect** and a dangerous misconception; infants, even neonates, have a **fully developed pain pathway**, perceive pain, and require appropriate analgesia. - The **pain response** in infants can be more exaggerated due to an immature inhibitory pain system, necessitating careful and effective pain management.

Q: A 5 year old healthy child is undergoing strabismus surgery with a Laryngeal mask airway in place. Thirty minutes into the procedure, his heart rate is 60 bpm, blood pressure is 90/60 mmHg, and oximeter shows 98% saturation. The next step in management is

Inform surgeon, administer atropine. ***Inform surgeon, administer atropine*** - **Oculocardiac reflex** is a common complication during strabismus surgery, characterized by bradycardia, hypotension, and arrhythmias. The significant drop in heart rate (60 bpm in a 5-year-old child) and mild hypotension suggest this reflex. - The standard management for an oculocardiac reflex involves informing the surgeon to temporarily cease manipulation of the extraocular muscles and administering an **anticholinergic drug** like atropine to counteract the vagal stimulation. *Replace the LMA with endotracheal tube* - The patient's oxygen saturation of 98% indicates adequate ventilation and oxygenation with the LMA, so there is no immediate need for **airway intervention**. - Replacing the LMA with an endotracheal tube is a more invasive procedure and would not directly address the underlying cause of bradycardia, which is likely due to the oculocardiac reflex. *Nothing, this is normal for this child* - A heart rate of 60 bpm is **significantly low** for a 5-year-old child under anesthesia, as the expected heart rate for this age group is typically much higher (around 80-120 bpm). - Ignoring this bradycardia could lead to further compromise in **cardiac output** and tissue perfusion if not addressed promptly. *Increase FiO2 to 1.0* - The current oxygen saturation of 98% indicates **adequate oxygenation**, so increasing the FiO2 would not address the bradycardia or hypotension. - While maintaining good oxygenation is important, this step would not resolve the primary issue of an **oculocardiac reflex** causing vagal stimulation.

Q: Infants require which of the following regarding anesthetic agents?

Higher amount of anaesthetic agent. ***Higher amount of anaesthetic agent*** - Infants generally have a **larger volume of distribution** for many drugs due to a higher proportion of total body water and lower fat content, necessitating higher doses per kilogram. - Their **metabolic pathways** and **organ function** (especially hepatic and renal) are immature, which can affect clearance and drug half-life, but often the initial dosing might be higher due to distribution differences. *Equal amount as in adults* - This is incorrect as infants have significant physiological differences compared to adults, particularly in **drug distribution**, **metabolism**, and **excretion**. - Dosing anesthetics based on adult equivalents would likely lead to **underdosing** or **overdosing** due to these differences. *Least amount of anaesthetic agent* - While some medications may require lower doses in neonates due to immature metabolic pathways, many anesthetic agents, particularly those with a high volume of distribution, may require **higher doses per kilogram** to achieve the desired effect. - The concept of "least amount" is overly simplistic and does not account for the **pharmacokinetic differences** in infants. *None of the options* - This is incorrect because one of the provided options accurately reflects the general requirement for anesthetic agents in infants.

Q: Which of the following is a pleasant anaesthetic agent preferred for inhalation mask anaesthesia in children?

Sevoflurane. ***Sevoflurane*** - Sevoflurane is known for its **low pungency and sweet smell**, making it well-tolerated by children for mask induction. - It has a **rapid onset and offset** due to its low blood-gas solubility, allowing for quick control of anesthesia depth. *Isoflurane* - Isoflurane has a **pungent odor** and is irritating to the airway, often causing coughing and laryngospasm during mask induction. - It is typically not the preferred choice for **inhalation induction in pediatric patients** due to these airway irritant properties. *Desflurane* - Desflurane is highly **pungent and irritating to the airway**, causing a high incidence of coughing, breath-holding, and laryngospasm. - Its use for mask induction, especially in children, is **contraindicated** due to severe airway irritation. *Enflurane* - Enflurane has a **pungent odor** and can be irritating to the airway, similar to isoflurane. - It is also associated with a higher risk of **seizure activity** at deeper anesthetic depths, limiting its use in pediatric patients.

Question 1

Why is there a higher incidence of endobronchial intubation in pediatric patients?

Accepted Answer

Short trachea

Answer

Longer pediatric endotracheal tube

Answer

Both

Answer

None of the above

Question 2

What is the anesthetic of choice in a child with cyanotic heart disease?

Accepted Answer

Ketamine

Answer

Propofol

Answer

Thiopentone

Answer

Sevoflurane

Question 3

Which of the following statements about the infant airway compared to the adult airway is FALSE?

Accepted Answer

All of the above are true statements about the infant airway

Answer

The relatively large size of the tongue

Answer

The epiglottis is omega shaped

Answer

The larynx is funnel shaped

Question 4

A child with bladder exstrophy posted for operative repair has renal failure. Which anesthetic agent should be preferred?

Accepted Answer

Vecuronium

Answer

Pancuronium

Answer

Atracurium

Answer

Rocuronium

Question 5

The size of endotracheal tube in a child < 6 years old is calculated using which formula?

Accepted Answer

(Age ÷ 4) + 3.5

Answer

(Age ÷ 4) - 4.5

Answer

(Age ÷ 4) + 4.5

Answer

(Age ÷ 4) + 2.5

Question 6

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 –

Accepted Answer

Sevoflurane

Answer

Isoflurane

Answer

Enflurane

Answer

Halothane

Question 7

A two month old infant has undergone a major surgical procedure. Regarding postoperative pain relief which one of the following is recommended:

Accepted Answer

Intravenous narcotic infusion in lower dosage

Answer

Spinal narcotics intrathecal route

Answer

Only paracetamol suppository is adequate

Answer

No medication is needed as infant does not feel pain after surgery due to immaturity of nervous system

Question 8

A 5 year old healthy child is undergoing strabismus surgery with a Laryngeal mask airway in place. Thirty minutes into the procedure, his heart rate is 60 bpm, blood pressure is 90/60 mmHg, and oximeter shows 98% saturation. The next step in management is

Accepted Answer

Inform surgeon, administer atropine

Answer

Replace the LMA with endotracheal tube

Answer

Nothing, this is normal for this child

Answer

Increase FiO2 to 1.0

Question 9

Infants require which of the following regarding anesthetic agents?

Accepted Answer

Higher amount of anaesthetic agent

Answer

Equal amount as in adults

Answer

Least amount of anaesthetic agent

Answer

None of the options

Question 10

Which of the following is a pleasant anaesthetic agent preferred for inhalation mask anaesthesia in children?

Accepted Answer

Sevoflurane

Answer

isoflurane

Answer

Desflurane

Answer

Enflurane

Pediatric Anesthesia — MCQs

Pediatric Anesthesia — MCQs

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