Respiratory and Airway Management Practice Questions

Q: During preanaesthetic evaluation, an anaesthetist wrote a Mallampati grade 3. What does this signify?

Soft palate and base of uvula visible. **Soft palate and base of uvula visible** - A **Mallampati grade 3** classification indicates that only the **soft palate** and the **base of the uvula** are visible when the patient opens their mouth and protrudes their tongue. - This grade suggests a moderate difficulty for **endotracheal intubation** because the visualization of the glottis may be partially obstructed. *Limited neck extension* - Limited **neck extension** is assessed separately during a preanesthetic evaluation and is not directly indicated by the Mallampati score. - It is a factor that can independently contribute to a difficult airway by limiting the ability to achieve the **sniffing position** for intubation. *An enlarged epiglottis* - The **epiglottis** is not visible during a standard awake Mallampati examination, which assesses oral pharyngeal structures. - Visualization of the epiglottis typically occurs during **laryngoscopy** and an enlarged epiglottis (e.g., in epiglottitis) is a medical emergency, not a Mallampati finding. *Jaw stiffness* - **Jaw stiffness** or limited mouth opening is assessed by measuring the **interincisor distance** and is not directly part of the Mallampati classification process. - Significant jaw stiffness can independently predict a difficult airway by restricting the view during laryngoscopy, even with a favorable Mallampati score.

Q: Difficult intubation is anticipated in all except the following conditions.

Receding incisors. ***Receding incisors*** - **Receding incisors** do not typically obstruct the laryngoscope blade or alter the alignment of the oral, pharyngeal, and laryngeal axes, making intubation easier rather than difficult. - A receding or absent maxilla can actually improve the line of sight to the **glottis**, reducing the likelihood of a difficult intubation. *Increase in posterior depth of mandible* - An **increased posterior depth of the mandible** (a large jaw) can make intubation more challenging by increasing the distance from the incisors to the larynx, making it harder to visualize the glottis. - This anatomical feature can limit the space for manipulating the **laryngoscope blade** and positioning the airway. *Increased alveolar- mental distance* - An **increased alveolar-mental distance** refers to a longer distance from the alveolar ridge to the mental protuberance, which indicates a longer mandible. - A longer mandible can push the laryngeal axis posteriorly, making it difficult to align the oral, pharyngeal, and laryngeal axes for direct **laryngoscopy**. *Temporomandibular joint fibrosis* - **Temporomandibular joint fibrosis** restricts mouth opening, a crucial factor for successful intubation. - Limited mouth opening significantly impedes the insertion and manipulation of the **laryngoscope blade**, making glottis visualization difficult or impossible.

Q: All of the following are related to difficult intubation, except which of the following?

Increased thyromental distance. ***Increased thyromental distance*** - An **increased thyromental distance** (greater than 6.5 cm) indicates more space between the mental protuberance and the thyroid cartilage, suggesting better laryngeal visualization and thus a **lower likelihood of difficult intubation**. - This measurement correlates with the adequacy of the submandibular space, which is crucial for achieving an optimal sniffing position for intubation. *Miller's sign* - **Miller's sign** refers to a prominent or anterior larynx, which can make it challenging to visualize the glottis during direct laryngoscopy. - This anatomical feature can obstruct the view of the vocal cords, thereby increasing the difficulty of intubation. *TMJ ankylosis* - **Temporomandibular joint (TMJ) ankylosis** significantly restricts mouth opening, which is essential for laryngoscope insertion and laryngeal visualization. - Limited mouth opening is a well-established predictor of **difficult intubation** because it prevents adequate alignment of the oral, pharyngeal, and laryngeal axes. *Micrognathia* - **Micrognathia**, or a small mandible, is associated with a posterior displacement of the tongue and a reduction in the space available for laryngoscope insertion. - This anatomical variation makes it difficult to achieve an adequate view of the glottis and can lead to **difficult or failed intubation**.

Q: What is the most appropriate anaesthesia technique for microlaryngoscopy?

Conventional endotracheal intubation. ***Conventional endotracheal intubation*** - While other techniques exist, **conventional endotracheal intubation** remains a widely accepted and often preferred method for microlaryngoscopy due to its ability to provide a secure airway, excellent surgical exposure, and controlled ventilation. - This technique allows for adequate **oxygenation and ventilation** during the procedure, which can be prolonged, and it protects the airway from **blood and secretions**. *Jet ventilation with TIVA* - **Jet ventilation** can provide an unobstructed laryngeal view and may be used, but it carries risks such as barotrauma and aspiration, and can cause difficulty with **CO2 clearance**. - While **total intravenous anesthesia (TIVA)** is suitable, the ventilation technique itself may not be the most appropriate primary choice due to its potential complications. *Apneic technique with TIVA* - The **apneic technique** (apneic oxygenation) may offer an unobstructed surgical field but is limited by the duration an individual can be safely apneic without hypercapnia or desaturation and a lack of control over ventilation for longer procedures. - Although **TIVA** is a good anesthetic choice, relying solely on an apneic period for the whole procedure may not be the safest or most practical method for many microlaryngoscopies. *Laryngeal mask airway with spontaneous ventilation* - A **laryngeal mask airway (LMA)** may provide a good view for some laryngeal procedures but does not offer the same level of airway protection against aspiration as an endotracheal tube. - **Spontaneous ventilation** with an LMA might not provide adequate control over gas exchange, especially if the procedure is prolonged or deep anesthesia is required.

Q: In status asthmaticus, which anesthetic agent is used as a bronchodilator?

Ketamine. ***Ketamine*** - Possesses **bronchodilatory** properties due to its sympathomimetic effects, making it useful in severe asthma or **status asthmaticus**. - It can cause **catecholamine release**, leading to relaxation of bronchial smooth muscle and improved airflow. *Morphine* - Can cause **histamine release**, which may lead to **bronchoconstriction** and worsen an asthmatic patient's condition. - It is a respiratory depressant that can further compromise breathing in a patient with severe airway obstruction. *Thiopentone sodium* - May induce **histamine release** and cause **bronchospasm**, which is contraindicated in asthma. - It is a potent depressant of the central nervous system and can cause respiratory depression, worsening the clinical picture of status asthmaticus. *Halothane* - Although it has some **bronchodilatory** properties, its use has largely been replaced by newer inhalational anesthetics due to concerns about myocardial sensitization to catecholamines and potential **hepatotoxicity**. - It is a potent inhalational agent but is less favored in modern anesthesia for asthma due to side effect profiles compared to other agents.

Q: All are indications for one-lung ventilation except which of the following?

General anesthesia without lung isolation. ***General anesthesia without lung isolation*** - One-lung ventilation (OLV) is specifically performed to achieve **lung isolation**, which is the opposite of general anesthesia without lung isolation. - The goal of OLV is to collapse one lung to facilitate surgical access or prevent contamination, making general anesthesia without isolation a contraindication. *Bronchopleural fistula* - OLV is indicated in cases of **bronchopleural fistula** to prevent leakage of air from the affected lung into the intact lung. - This helps to maintain adequate ventilation and oxygenation in the healthy lung while the fistula can be managed or repaired. *Massive hemorrhage in one lung* - **Massive hemorrhage** in one lung is a critical indication for OLV to prevent the spread of blood to the contralateral healthy lung. - Isolating the bleeding lung protects the airway and facilitates surgical control of the hemorrhage. *Video-assisted thoracoscopic surgery* - **Video-assisted thoracoscopic surgery (VATS)** procedures frequently require OLV to collapse the operative lung. - This provides a clear surgical field and sufficient working space for the surgeon to perform the procedure without lung movement obstructing the view.

Q: Who is credited with the development of the LMA ProSeal?

Brain. ***Brain*** - Dr. Archie Brain invented the **Laryngeal Mask Airway (LMA)**, and he subsequently developed the **LMA ProSeal**, an advanced version with a gastric access port. - The LMA ProSeal was designed to provide better sealing pressures and allow for gastric decompression while maintaining airway patency. *Bailey* - Dr. Owen Bailey is known for his contributions to **cardiac surgery**, particularly in the field of mitral valve repair. - His work is focused on surgical techniques rather than airway management devices like the LMA. *Macewan* - Sir William Macewan was a prominent 19th-century surgeon known for his pioneering work in **neuro- and general surgery**, including the first successful removal of a brain tumor. - His contributions are in surgical techniques and not in the development of supraglottic airway devices. *Magill* - Sir Ivan Magill was an Irish anesthetist known for his significant contributions to **anesthesia**, including the development of the Magill forceps and the Magill endotracheal tube. - While he developed crucial airway tools, the LMA ProSeal was not among his inventions.

Q: IPPV can cause all of the following complications except:

Pulmonary embolism. **Pulmonary embolism** - **Mechanical ventilation**, particularly intermittent positive pressure ventilation (IPPV), is not a direct cause of pulmonary embolism. - While prolonged immobility and venous stasis in critically ill patients can increase the risk of deep vein thrombosis (DVT) and subsequent PE, IPPV itself does not directly induce thrombus formation. *Barotrauma* - **High inspiratory pressures** and large tidal volumes used during IPPV can overdistend alveoli, leading to rupture and air leaks. - This can result in conditions like **pneumothorax**, **pneumomediastinum**, and **subcutaneous emphysema**. *Pneumonia* - IPPV is a significant risk factor for **ventilator-associated pneumonia (VAP)** due to the presence of an endotracheal tube. - The tube bypasses natural airway defenses, facilitating bacterial colonization and aspiration of secretions. *Hypotension* - Positive pressure applied during IPPV can increase **intrathoracic pressure**, which in turn reduces venous return to the heart. - This decrease in preload directly leads to a **reduction in cardiac output** and systemic blood pressure, causing hypotension.

Q: The most common cause of hypoxia during one-lung ventilation is:

Malposition of the double-lumen tube. ***Malposition of the double-lumen tube*** - **Malposition** of the double-lumen tube can lead to **obstruction of airflow** to the ventilated lung or incomplete isolation of the non-ventilated lung, resulting in significant **ventilation-perfusion mismatch** and **hypoxia**. - Incorrect placement is a common and often immediate cause of hypoxemia during one-lung ventilation because it directly interferes with the intended strategy of isolating and ventilating one lung while collapsing the other. *Increased shunt fraction* - While an **increased shunt fraction** is the physiological mechanism explaining hypoxia during one-lung ventilation, it is the *result* of various causes, not the primary cause itself. - The shunt fraction increases naturally due to blood flow through the non-ventilated lung, but a *pathological* increase causing severe hypoxia suggests another underlying problem like inadequate hypoxic pulmonary vasoconstriction or malposition of the tube. *Collapse of one lung* - The **collapse of one lung** is an *intended outcome* of one-lung ventilation to facilitate surgical access, and by itself, it is not the most common *cause* of hypoxia. - While collapse contributes to shunt, the body normally compensates through **hypoxic pulmonary vasoconstriction**; severe hypoxia typically points to a failure of this compensation or other issues. *Soiling of lung by secretions* - **Soiling of the lung by secretions** can certainly cause hypoxia by obstructing airways and increasing shunt but is **less common** than issues related to tube placement. - This typically causes **sudden deterioration** and requires immediate suctioning, but malposition is a more frequent initial problem during setup or with patient movement.

Question 1

During preanaesthetic evaluation, an anaesthetist wrote a Mallampati grade 3. What does this signify?

Accepted Answer

Soft palate and base of uvula visible

Answer

Limited neck extension

Answer

An enlarged epiglottis

Answer

Jaw stiffness

Question 2

Difficult intubation is anticipated in all except the following conditions.

Accepted Answer

Receding incisors

Answer

Increase in posterior depth of mandible

Answer

Increased alveolar- mental distance

Answer

Temporomandibular joint fibrosis

Question 3

All of the following are related to difficult intubation, except which of the following?

Accepted Answer

Increased thyromental distance

Answer

TMJ ankylosis

Answer

Micrognathia

Answer

Miller's sign

Question 4

What is the most appropriate anaesthesia technique for microlaryngoscopy?

Accepted Answer

Conventional endotracheal intubation

Answer

Jet ventilation with TIVA

Answer

Apneic technique with TIVA

Answer

Laryngeal mask airway with spontaneous ventilation

Question 5

In status asthmaticus, which anesthetic agent is used as a bronchodilator?

Accepted Answer

Ketamine

Answer

Morphine

Answer

Thiopentone sodium

Answer

Halothane

Question 6

All are indications for one-lung ventilation except which of the following?

Accepted Answer

General anesthesia without lung isolation

Answer

Massive hemorrhage in one lung

Answer

Bronchopleural fistula

Answer

Video-assisted thoracoscopic surgery

Question 7

What position of the patient facilitates the maximum depression of the soft palate?

Accepted Answer

The patient is seated upright with the head straight.

Answer

The patient is in a lateral position.

Answer

The patient is in a prone position.

Answer

The patient is in a supine position with the head slightly extended.

Question 8

Who is credited with the development of the LMA ProSeal?

Accepted Answer

Brain

Answer

Bailey

Answer

Macewan

Answer

Magill

Question 9

IPPV can cause all of the following complications except:

Accepted Answer

Pulmonary embolism

Answer

Barotrauma

Answer

Pneumonia

Answer

Hypotension

Question 10

The most common cause of hypoxia during one-lung ventilation is:

Accepted Answer

Malposition of the double-lumen tube

Answer

Increased shunt fraction

Answer

Collapse of one lung

Answer

Soiling of lung by secretions

Respiratory and Airway Management — MCQs

Respiratory and Airway Management — MCQs

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