Respiratory and Airway Management Practice Questions

Q: Size of the laryngeal mask airway for normal adults-

3. ***3*** - A size **3 LMA** is generally recommended for an average adult, especially adult females, weighing approximately 30-50 kg. - This size provides an adequate seal for ventilating normal adult airways when a larger LMA (size 4 or 5) may not be suitable based on patient size or anatomy. *2.5* - A size **2.5 LMA** is typically used for older children (ages 6-12 years) or smaller pediatric patients, not normal adults. - Using a size 2.5 in an adult would likely result in an inadequate seal and poor ventilation. *4* - A size **4 LMA** is commonly used for larger adult males weighing approximately 50-70 kg or more. - While suitable for some adults, it may be too large for an "average" adult, potentially causing pharyngeal trauma or poor positioning. *1.5* - A size **1.5 LMA** is designed for infants or very small children, typically those weighing 5-10 kg. - This size is much too small for any adult and would provide no effective airway management.

Q: Which of the following is an ideal method to prevent aspiration pneumonia?

Endotracheal tube (cuffed). ***Endotracheal tube (cuffed)*** - A cuffed endotracheal tube forms a **seal** in the trachea, effectively preventing aspiration of gastric contents or oral secretions into the lungs. - This method is particularly crucial before and during surgical procedures involving general anesthesia, where normal airway protective reflexes are abolished. *Full stomach* - A **full stomach** significantly increases the risk of aspiration, as there is more gastric content available to be regurgitated into the airway. - This is a contraindication for immediate induction of general anesthesia and often necessitates a rapid sequence intubation. *Increase the intra abdominal pressure* - Increasing **intra-abdominal pressure** (e.g., due to obesity, insufflation for laparoscopy) can push gastric contents towards the esophagus, thereby increasing the risk of reflux and aspiration. - This effect is undesirable and directly contributes to aspiration risk rather than preventing it. *Inhalational anesthetic* - **Inhalational anesthetics** depress airway reflexes, making the patient more susceptible to aspiration. - While they are essential for maintaining anesthesia, they do not prevent aspiration; rather, other measures like intubation are necessary to counteract their effects.

Q: Which is not an obvious advantage of high-flow nasal cannula (HFNC):

Bypassing nasopharyngeal dead space. ***Bypassing nasopharyngeal dead space*** - While HFNC does washout **CO2 from the nasopharynx** through high flow rates, this mechanism is more subtle and physiologically complex, making it a **less obvious advantage** compared to the other benefits. - This effect requires understanding of **dead space physiology** and gas exchange mechanics, unlike the more immediately apparent clinical benefits of HFNC. *Decreases need for intubation* - This is an **obvious and well-established advantage** of HFNC, with multiple clinical studies demonstrating reduced **intubation rates** in acute respiratory failure. - The ability to avoid invasive mechanical ventilation is a **primary clinical endpoint** that makes HFNC therapy attractive to clinicians. *PEEP* - Generation of **positive end-expiratory pressure** is a **well-recognized advantage** of HFNC, typically providing 2-8 cmH2O depending on flow rates. - This **obvious benefit** helps with **alveolar recruitment** and improved oxygenation, making it a clear therapeutic advantage. *Hot and Humidification of air* - This is the **most obvious advantage** of HFNC, delivering **warmed (37°C)** and **100% humidified** oxygen directly to patients. - Prevents **mucosal drying**, improves **mucociliary clearance**, and enhances patient comfort - benefits that are immediately apparent in clinical practice.

Q: Time required for pre-oxygenation before tracheal intubation:

3 min. ***3 min*** - Pre-oxygenation typically involves administering 100% oxygen for **3 minutes** via a tight-fitting face mask. - This duration allows for **denitrogenation** of the functional residual capacity (FRC), replacing nitrogen with oxygen to create an oxygen reserve. *1 min* - **One minute** of pre-oxygenation is generally insufficient to adequately denitrogenate the FRC, especially in patients with normal respiratory function. - This duration would lead to a shorter safe apnea time and increased risk of **hypoxemia** during intubation. *5 min* - While 5 minutes of pre-oxygenation provides a slightly larger oxygen reserve, it is usually not necessary and offers little additional benefit over **3 minutes** in a healthy adult. - Prolonged pre-oxygenation can be less practical in emergency settings and could potentially delay intubation without significant clinical advantage. *2 min* - **Two minutes** of pre-oxygenation may provide some benefit but is generally considered suboptimal compared to 3 minutes for maximizing the **oxygen reserve**. - Healthy individuals can typically be safely intubated after 2 minutes of pre-oxygenation, but 3 minutes allows for a more robust safety margin.

Q: Steps of intubation - arrange in sequence:- a. Head extension and flexion of neck b. Introduction of laryngoscope c. Inflation of cuff d. Check breath sounds with stethoscope e. fixation of the tube to prevent dislodgement

ABCDE. **ABCDE** - The correct sequence for intubation starts with proper patient positioning (**A. Head extension and flexion of neck**) followed by insertion of the laryngoscope (**B. Introduction of laryngoscope**). - After visualizing the glottis and inserting the endotracheal tube, the cuff is inflated (**C. Inflation of cuff**), tube placement is confirmed by checking breath sounds (**D. Check breath sounds with stethoscope**), and finally, the tube is secured (**E. Fixation of the tube to prevent dislodgement**). *CBAED* - This sequence is incorrect because inflating the cuff (C) and introducing the laryngoscope (B) occur before head positioning (A), and checking breath sounds (E) and fixation (D) are not in the correct order after intubation. - Proper patient positioning is the critical first step to align the oral, pharyngeal, and laryngeal axes for optimal visualization. *ACBED* - This sequence incorrectly places the inflation of the cuff (C) before the introduction of the laryngoscope (B) and confirmation steps (E and D). - The cuff is inflated only after the tube is properly placed in the trachea, and confirmation of placement always precedes fixation. *DBCEA* - This sequence is incorrect as it begins with checking breath sounds (D), which is a step for confirming tube placement, not initiating the intubation process. - Head positioning (A) is also placed last, which is contrary to the vital initial steps of airway management for intubation.

Q: Highest concentration of oxygen is delivered through?

Mask with reservoir. ***Mask with reservoir*** - A mask with a reservoir bag, particularly a **non-rebreather mask**, delivers the highest concentration of oxygen (up to 95-100%). - The **reservoir bag** and **one-way valves** prevent entrainment of room air and re-breathing of exhaled CO2, maximizing oxygen delivery. *Bag and mask* - While capable of delivering high oxygen concentrations, its effectiveness is highly dependent on a **proper seal** and the technique of the rescuer. - Its primary role is for **manual ventilation** rather than sustained high-concentration oxygen delivery alone. *Venturi mask* - The Venturi mask is known for delivering **precise and controlled oxygen concentrations**, not necessarily the highest. - It uses a jet of oxygen to entrain fixed amounts of room air, maintaining a **consistent FiO2** (fraction of inspired oxygen). *Nasal cannula* - A nasal cannula delivers relatively **low concentrations of oxygen** (24-44%), as it mixes with a large volume of room air. - It is suitable for **mild to moderate hypoxemia** but cannot provide the high FiO2 needed in critical situations.

Q: A 45-year-old patient develops bronchospasm during induction. Which inhalational agent is most suitable for management?

Sevoflurane. ***Sevoflurane*** - **Sevoflurane** is an excellent choice for managing intraoperative **bronchospasm** due to its low airway irritancy and potent **bronchodilating** properties. - Its rapid onset and offset allow for quick adjustment of anesthetic depth to help relieve airway constriction. *Halothane* - While **halothane** has significant **bronchodilating effects**, its use is limited due to concerns about **hepatotoxicity** (halothane hepatitis) and cardiac arrhythmias. - It is rarely used in modern anesthetic practice, especially when safer alternatives like sevoflurane are available. *Isoflurane* - **Isoflurane** is a **bronchodilator**, but it tends to be more **pungent** and airway irritant than sevoflurane, potentially exacerbating bronchospasm upon induction or during light anesthesia. - It has a slower onset and offset compared to sevoflurane, making it less ideal for rapid resolution of an acute bronchospasm. *Desflurane* - **Desflurane** is a known **airway irritant** and can precipitate or worsen **bronchospasm**, particularly in patients with reactive airway disease, making it unsuitable for this scenario. - Its strong smell and propensity to cause coughing and laryngospasm make it contraindicated during induction in patients at risk for bronchospasm.

Q: Child with aspiration risk needs emergency surgery. Best induction sequence is:

Preoxygenation-propofol-succinylcholine. ***Preoxygenation-propofol-succinylcholine*** - This sequence describes a **rapid sequence intubation (RSI)**, which is the preferred method for patients at high risk of aspiration, including children needing emergency surgery with an unknown fasting status. - **Preoxygenation** provides an oxygen reserve during the apneic period, **propofol** offers rapid induction with good hemodynamic stability, and **succinylcholine** provides fast-onset, short-acting neuromuscular blockade, crucial for preventing aspiration. *Preoxygenation-ketamine-succinylcholine* - While preoxygenation and succinylcholine are appropriate for RSI, **ketamine** may not be the optimal choice for a child with aspiration risk due to its potential to increase secretions and maintain laryngeal reflexes, which could complicate intubation. - Ketamine can also cause **emergence delirium** in some children, making it less favorable for a smooth anesthetic course compared to propofol. *Sevoflurane-propofol-succinylcholine* - **Sevoflurane** is an inhaled anesthetic often used for mask induction in children due to its non-pungent odor and rapid onset. However, it is generally **not suitable for RSI** in patients with aspiration risk as it has a slower induction time compared to intravenous agents and can cause coughing or laryngospasm. - Using both sevoflurane and propofol for induction in an RSI scenario is redundant and prolongs the induction phase, increasing aspiration risk. *Midazolam-propofol-rocuronium* - **Midazolam** is a benzodiazepine used for anxiolysis and sedation but has a **slower onset** and longer duration of action compared to propofol for rapid induction. - **Rocuronium** is a non-depolarizing neuromuscular blocker with a slower onset of action than succinylcholine, making it less ideal for RSI where immediate paralysis for intubation is critical to prevent aspiration.

Q: Patient with BMI 40 presents for emergency surgery. All are correct about airway management EXCEPT:

Avoid cricoid pressure. ***Avoid cricoid pressure*** - While **cricoid pressure** (Sellick's maneuver) is used to prevent **aspiration** by compressing the esophagus, its effectiveness in **obese patients** is highly debated and often hindered by excess neck tissue. - In obese patients, cricoid pressure can actually worsen the view during laryngoscopy, making intubation more difficult and potentially causing airway trauma. *Extended ramping* - **Ramping** the patient, where the head and shoulders are elevated, is crucial in **obese patients** to align the **oral, pharyngeal, and laryngeal axes**. - This position improves the view during laryngoscopy and facilitates successful intubation by effectively displacing excess tissue. *Rapid sequence induction* - **Rapid sequence induction (RSI)** is often indicated in **obese patients** undergoing emergency surgery due to their increased risk of **gastric reflux** and **pulmonary aspiration**. - RSI involves administering a sedative and a paralytic agent in rapid succession, followed immediately by intubation, to minimize the time the airway is unprotected. *Avoid preoxygenation* - **Preoxygenation** is essential in **obese patients** to maximize their **oxygen reserves** before intubation. - Obese patients have reduced **functional residual capacity (FRC)** and increased **oxygen consumption**, making them desaturate rapidly during apnea, so preoxygenation significantly prolongs safe apnea time.

Question 1

Size of the laryngeal mask airway for normal adults-

Accepted Answer

3

Answer

2.5

Answer

4

Answer

1.5

Question 2

Which of the following is an ideal method to prevent aspiration pneumonia?

Accepted Answer

Endotracheal tube (cuffed)

Answer

Full stomach

Answer

Increase the intra abdominal pressure

Answer

Inhalational anesthetic

Question 3

Which is not an obvious advantage of high-flow nasal cannula (HFNC):

Accepted Answer

Bypassing nasopharyngeal dead space

Answer

Hot and Humidification of air

Answer

Decreases need for intubation

Answer

PEEP

Question 4

Time required for pre-oxygenation before tracheal intubation:

Accepted Answer

3 min

Answer

1 min

Answer

5 min

Answer

2 min

Question 5

A Patient in medical intensive care unit who is intubated, suddenly removes the endotracheal tube. What should be done next?

Accepted Answer

Assess the patient and give bag and mask ventilation and look for spontaneous breathing

Answer

Sedate and reintubate

Answer

Make him sit and do physiotherapy

Answer

Give bag and mask ventilation and intubate

Question 6

Steps of intubation - arrange in sequence:- a. Head extension and flexion of neck b. Introduction of laryngoscope c. Inflation of cuff d. Check breath sounds with stethoscope e. fixation of the tube to prevent dislodgement

Accepted Answer

ABCDE

Answer

CBAED

Answer

ACBED

Answer

DBCEA

Question 7

Highest concentration of oxygen is delivered through?

Accepted Answer

Mask with reservoir

Answer

Bag and mask

Answer

Venturi mask

Answer

Nasal cannula

Question 8

A 45-year-old patient develops bronchospasm during induction. Which inhalational agent is most suitable for management?

Accepted Answer

Sevoflurane

Answer

Halothane

Answer

Isoflurane

Answer

Desflurane

Question 9

Child with aspiration risk needs emergency surgery. Best induction sequence is:

Accepted Answer

Preoxygenation-propofol-succinylcholine

Answer

Preoxygenation-ketamine-succinylcholine

Answer

Sevoflurane-propofol-succinylcholine

Answer

Midazolam-propofol-rocuronium

Question 10

Patient with BMI 40 presents for emergency surgery. All are correct about airway management EXCEPT:

Accepted Answer

Avoid cricoid pressure

Answer

Extended ramping

Answer

Rapid sequence induction

Answer

Avoid preoxygenation

Respiratory and Airway Management — MCQs

Respiratory and Airway Management — MCQs

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