Respiratory and Airway Management — MCQs

Respiratory and Airway Management Indian Medical PG Practice Questions and MCQs

Question 321: Which is not an obvious advantage of high-flow nasal cannula (HFNC):

A. Bypassing nasopharyngeal dead space
B. Hot and Humidification of air (Correct Answer)
C. PEEP
D. Decreases need for intubation

Explanation: *Hot and Humidification of air* - This is an **obvious advantage** of HFNC, as it delivers warmed and humidified oxygen directly, improving patient comfort and mucociliary clearance. - The constant flow ensures the upper airway mucosa remains hydrated, preventing dryness and irritation that can occur with conventional oxygen therapy. ***Bypassing nasopharyngeal dead space*** - While HFNC does replace the gas in the **nasopharynx** with fresh gas, reducing dead space, this benefit is related to the high flow rate and is considered an **obvious advantage** in improving ventilatory efficiency. - The continuous washout of CO2 from the upper airway directly contributes to improved gas exchange. *PEEP* - HFNC can generate a modest level of **positive end-expiratory pressure (PEEP)**, which is an intentional and recognized effect due to the high flow rates. - This PEEP helps to recruit collapsed alveoli and improve oxygenation, making it an **obvious advantage** in respiratory support. *Decreases need for intubation* - The ability of HFNC to improve oxygenation, reduce work of breathing, and minimize airways inflammation is a well-established and **obvious advantage** that often prevents the need for invasive mechanical ventilation. - Clinical studies consistently demonstrate that HFNC can reduce intubation rates in patients with acute respiratory failure.

Question 322: Time required for pre-oxygenation before tracheal intubation:

A. 1 min
B. 5 min
C. 3 min (Correct Answer)
D. 2 min

Explanation: ***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.

Question 323: Which of the following is most associated with respiratory alkalosis?

A. SIMV
B. Non invasive ventilation
C. Pressure controlled
D. Assisted control mode ventilation (Correct Answer)

Explanation: ***Assisted control mode ventilation*** - In **assisted control mode**, every patient effort above a set sensitivity triggers a fully supported breath at the set tidal volume or pressure, leading to the potential for **excessive ventilation** and respiratory alkalosis if the patient's respiratory drive is high. - This mode ensures a **minimum number of breaths** per minute, but also delivers full mechanical breaths for any additional patient-initiated breaths, which can result in **hyperventilation**. *SIMV* - **Synchronized intermittent mandatory ventilation (SIMV)** delivers a set number of mandatory breaths, but patient-initiated breaths between these mandatory breaths are either unsupported or supported at a lower level, making it less prone to causing excessive ventilation and alkalosis compared to AC. - SIMV allows for more patient participation in breathing and is often used to **wean patients off ventilation**, whereas AC prioritizes full ventilatory support. *Non invasive ventilation* - While **non-invasive ventilation (NIV)** can cause respiratory alkalosis if settings are too aggressive, it is generally used to avoid intubation and often allows for more patient control over their breathing pattern than AC, especially in modes like BiPAP where inspiratory and expiratory pressures are set. - The goal of NIV is to provide ventilatory support without an artificial airway, and it can be titrated to prevent both hypoventilation and hyperventilation more easily than the full support of AC. *Pressure controlled* - **Pressure-controlled ventilation** delivers breaths until a set inspiratory pressure is reached, with tidal volume varying based on lung compliance and resistance. While it can cause respiratory alkalosis if the set pressure or respiratory rate is too high, it is a *mode* of ventilation rather than a specific *type* of ventilatory support that inherently overventilates. - It focuses on limiting peak inspiratory pressures to protect the lungs, and can be used in either AC or SIMV modes, making its association with alkalosis dependent on specific settings and patient interaction.

Question 324: 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

A. CBAED
B. ACBED
C. DBCEA
D. ABCDE (Correct Answer)

Explanation: **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.

Question 325: Highest concentration of oxygen is delivered through?

A. Bag and mask
B. Venturi mask
C. Nasal cannula
D. Mask with reservoir (Correct Answer)

Explanation: ***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.

Question 326: Patient with BMI 40 presents for emergency surgery. All are correct about airway management EXCEPT:

A. Extended ramping
B. Avoid cricoid pressure (Correct Answer)
C. Rapid sequence induction
D. Avoid preoxygenation

Explanation: ***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 327: What is the most common cause of death in anesthesia-related malpractice claims?

A. Airway obstruction (Correct Answer)
B. Medication errors
C. Cardiovascular events
D. Aspiration

Explanation: ***Airway obstruction*** - **Airway obstruction** is frequently cited as the leading cause of death in anesthesia-related malpractice claims due to its rapid progression and critical impact on oxygenation. - Failure to adequately manage the airway, including challenges during intubation or extubation, or unrecognized dislodgement of the endotracheal tube, can quickly lead to **hypoxia** and subsequent cardiac arrest. *Cardiovascular events* - While serious, **cardiovascular events** like myocardial infarction or arrhythmias are often linked to pre-existing patient conditions or drug interactions, but are less commonly the primary root cause of death directly attributable to provider malpractice than airway issues. - The immediate onset and severity of **unmanaged airway compromise** typically lead to more rapid and irreversible outcomes compared to many cardiovascular incidents which may allow for more time for intervention. *Medication errors* - **Medication errors**, such as incorrect dosing or administration of anesthetics, can lead to adverse events, but fatal outcomes are often a result of systemic effects like respiratory depression or severe cardiovascular compromise which, while serious, occur less frequently than direct airway mismanagement. - Although significant, many **medication errors** are detectable and reversible if promptly identified, whereas severe airway obstruction can be immediately life-threatening. *Aspiration* - **Aspiration** of gastric contents into the lungs can lead to chemical pneumonitis and acute respiratory distress syndrome, which can be fatal. - However, aspiration is generally less frequent than problems directly related to maintaining a patent airway during the entire perioperative period.

Question 328: Which of the following is not an indication for cricoid pressure?

A. Difficult airway
B. Risk of aspiration
C. Rapid sequence induction
D. Elective intubation (Correct Answer)

Explanation: ***Elective intubation*** - Cricoid pressure is primarily used in **emergency situations** to prevent aspiration, where the patient's stomach may not be empty. - In **elective intubation**, the patient is typically fasted, significantly reducing the risk of aspiration, making cricoid pressure unnecessary and potentially detrimental. *Rapid sequence induction* - **Rapid sequence induction (RSI)** is a common indication for cricoid pressure, as it aims to achieve rapid intubation in patients with a full stomach to prevent aspiration. - The goal is to quickly secure the airway before regurgitation or vomiting can occur. *Difficult airway* - In a **difficult airway** scenario, applying cricoid pressure can actually worsen the view of the vocal cords or make tube placement more challenging. - It may obstruct the glottic opening, making endotracheal intubation more difficult and potentially delaying crucial airway management. *Risk of aspiration* - The primary purpose of **cricoid pressure** (also known as the Selick maneuver) is to occlude the esophageal lumen, thereby preventing the regurgitation of gastric contents into the airway. - This technique is applied when there is a high **risk of aspiration**, such as in patients with a full stomach, trauma, or altered mental status.

Question 329: In the management of a difficult airway, which of the following techniques is considered the gold standard?

A. Fiberoptic intubation (Correct Answer)
B. Direct laryngoscopy
C. Laryngeal mask airway
D. Video laryngoscopy

Explanation: ***Fiberoptic intubation*** - **Fiberoptic intubation** is considered the gold standard for **difficult airway management** due to its ability to visualize the airway directly and navigate around anatomical challenges. - It allows for intubation in conscious patients under local anesthesia, maintaining spontaneous ventilation and airway reflexes. *Video laryngoscopy* - While **video laryngoscopy** improves glottic visualization compared to direct laryngoscopy, it can still be challenging in extremely difficult airways or where secretions obscure the view. - It does not offer the same degree of maneuverability and control as fiberoptic scopes in highly distorted or narrow airways. *Direct laryngoscopy* - **Direct laryngoscopy** is the standard approach for routine intubations but often fails in difficult airways where visualization of the glottis is obstructed. - It requires alignment of the oral, pharyngeal, and laryngeal axes, which may be impossible in patients with neck immobility, anatomical variations, or trauma. *Laryngeal mask airway* - A **laryngeal mask airway (LMA)** is a supraglottic device used for ventilation, not definitive intubation. - While it can be a useful rescue device in a "cannot intubate, cannot ventilate" scenario, it does not secure the airway against aspiration as effectively as an endotracheal tube, nor does it allow for direct visualization of the larynx.

Question 330: During the induction of anesthesia in a patient with a history of difficult intubation, what is the best initial approach?

A. Use a video laryngoscope (Correct Answer)
B. Perform a cricothyrotomy
C. Administer a muscle relaxant immediately
D. Attempt blind nasal intubation

Explanation: ***Use a video laryngoscope*** - A **video laryngoscope** allows for an improved view of the glottis compared to direct laryngoscopy, which is crucial in patients with a history of **difficult intubation**. - It enhances the first-attempt success rate and reduces intubation-related trauma in these challenging situations. *Perform a cricothyrotomy* - **Cricothyrotomy** is a last-resort, life-saving procedure used when other intubation methods have failed and the patient cannot be ventilated; it is not an initial approach. - Performing this procedure too early carries risks, including **hemorrhage** and airway trauma, without first attempting less invasive and more appropriate methods. *Administer a muscle relaxant immediately* - While muscle relaxants facilitate intubation by relaxing the jaw and vocal cords, administering them *immediately* without a plan for managing a potentially failed airway can be dangerous, especially with a history of difficult intubation. - If intubation fails after paralysis, the patient cannot breathe spontaneously, leading to a **"cannot intubate, cannot ventilate"** scenario. *Attempt blind nasal intubation* - **Blind nasal intubation** is generally less preferred today due to the availability of safer and more effective techniques like fiberoptic or video laryngoscopy for difficult airways. - It carries risks such as **nasal bleeding**, **submucosal dissection**, and is not always successful, making it a high-risk primary approach for a known difficult airway.

Practice by Chapter

Respiratory Physiology

Practice Questions

Airway Anatomy

Practice Questions

Preoxygenation Techniques

Practice Questions

Mask Ventilation

Practice Questions

Supraglottic Airway Devices

Practice Questions

Direct Laryngoscopy

Practice Questions

Video Laryngoscopy

Practice Questions

Fiberoptic Intubation

Practice Questions

Surgical Airway Management

Practice Questions

One-Lung Ventilation Techniques

Practice Questions

Ventilation Strategies During Anesthesia

Practice Questions

Extubation Criteria and Techniques

Practice Questions

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