Respiratory and Airway Management Practice Questions

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: Which anaesthetic agent is contraindicated in patients with emphysema?

Nitrous oxide (N2O). ***Nitrous oxide (N2O)*** - **Nitrous oxide** diffuses rapidly into air-filled cavities, such as **bullae** in emphysema, causing them to expand. - This expansion can lead to **pneumothorax** or worsen existing respiratory compromise by increasing the size of trapped gas. *Halothane* - While it can cause **bronchodilation**, its use in emphysema is limited due to its potential for **cardiac depression** and **hepatotoxicity**. - It is not specifically contraindicated due to its effect on bullae or air trapping. *Diethyl ether* - This agent is largely obsolete due to its **flammability** and high incidence of **postoperative nausea and vomiting**. - Its effects on emphysematous lungs are less of a concern than its general anesthetic properties and side effects. *Isoflurane* - **Isoflurane** is often preferred in patients with respiratory disease due to its potent **bronchodilating properties** and minimal cardiac depression. - It does not expand air-filled spaces and is considered relatively safe for patients with emphysema.

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: 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: In infants, the narrowest part of the larynx is at the cricoid level. In administering anesthesia, which of the following is NOT a potential complication of using a smaller size endotracheal tube?

Choosing a smaller size endotracheal tube. ***Choosing a smaller size endotracheal tube*** - This option incorrectly states that *choosing a smaller size endotracheal tube* is a complication. It is a decision or action, not a direct complication of the tube itself. - While an *appropriately* sized smaller tube can be beneficial, the act of *choosing* it isn't inherently a complication. *Trauma to the subglottic region* - Using an **overly *large* endotracheal tube** can cause trauma to the **subglottic region**, which is the narrowest part of an infant's airway. - Trauma can lead to **edema**, **ulceration**, or even **scarring**, potentially resulting in **subglottic stenosis**. *Increased risk of airway obstruction* - An **endotracheal tube (ETT) that is too *small*** for the child can lead to various issues, including an **increased risk of obstruction** due to secretions or kinking. - A tube that is too small also offers higher resistance to airflow, making adequate ventilation more challenging and potentially requiring higher pressures. *Choosing an inappropriate size endotracheal tube* - *Choosing an inappropriate size endotracheal tube*, whether too large or too small, is a **patient safety concern** that can lead to various complications. - An **incorrectly sized tube** can result in complications ranging from air leak and inadequate ventilation (if too small) to direct airway trauma and post-extubation stridor (if too large).

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.

Q: What is the medical procedure that involves the insertion of a tube directly into the trachea to secure the airway and ensure adequate ventilation?

Endotracheal tube insertion. ### **Explanation** The correct answer is **Endotracheal tube (ETT) insertion**, also known as **intubation**. #### **1. Why Endotracheal Tube Insertion is Correct** The primary goal of airway management is to maintain a patent airway and provide mechanical ventilation. **Endotracheal intubation** involves passing a tube through the vocal cords directly into the **trachea**. This is considered the "gold standard" for securing the airway because: * It provides a **definitive airway**. * It protects the lungs from **aspiration** (via the inflatable cuff). * It allows for precise delivery of oxygen and anesthetic gases. #### **2. Analysis of Incorrect Options** * **Oral and Oropharyngeal Suction (A & B):** These are supportive procedures used to clear secretions, blood, or vomit from the mouth and pharynx. They do not involve entering the trachea or providing a conduit for ventilation. * **Nasogastric Tube Insertion (D):** This involves passing a tube through the nose into the **stomach**. It is used for gastric decompression or enteral feeding, not for respiratory management. #### **3. High-Yield Clinical Pearls for NEET-PG / INI-CET** * **Definition of a Definitive Airway:** A tube present in the **trachea** with the **cuff inflated** and connected to an oxygen-enriched ventilation source. * **Confirmation:** The most reliable clinical method to confirm ETT placement is **End-tidal CO₂ (Capnography)**. On physical exam, bilateral breath sounds and absence of gastric gurgling are essential. * **Goldman’s Rule:** The distance from the incisors to the mid-trachea is approximately **21 cm in females** and **23 cm in males**. * **Murphy’s Eye:** The small hole at the distal end of the ETT that prevents complete obstruction if the main tip is blocked by the tracheal wall.

Q: In which of the following conditions is Positive end-expiratory pressure (PEEP) beneficial?

Acute Respiratory Distress Syndrome (ARDS). ***Acute Respiratory Distress Syndrome (ARDS)*** - PEEP is crucial in ARDS to prevent **alveolar collapse** at end-expiration, improving oxygenation and reducing the risk of **ventilator-induced lung injury**. - It helps by **recruiting collapsed alveoli** and maintaining them open, thus increasing the functional residual capacity. *Pneumonia* - While pneumonia can cause hypoxemia, PEEP's benefit is less pronounced unless it progresses to **ARDS** or causes significant **atelectasis**. - Excessive PEEP can lead to barotrauma if lung compliance is relatively normal or if only a limited portion of the lung is affected. *Pulmonary edema* - PEEP can be helpful in **cardiogenic pulmonary edema** by reducing venous return and thus **preload**, as well as improving oxygenation. - However, it's not the primary or most universally beneficial intervention compared to its role in ARDS. *Chronic Obstructive Pulmonary Disease (COPD)* - PEEP must be used cautiously in COPD due to the risk of **dynamic hyperinflation** and **auto-PEEP**, which can increase air trapping. - While it might be cautiously applied to improve oxygenation or reduce work of breathing, it's generally not considered broadly beneficial and can be detrimental if not carefully managed.

Q: What is the intubation dose of pancuronium?

0.08 mg/Kg. ***0.08 mg/Kg*** - The standard **intubating dose** of pancuronium is typically **0.08-0.1 mg/kg intravenously**. - This dose provides adequate **neuromuscular blockade** for endotracheal intubation. *0.02 mg/Kg* - This dose is too low and would likely result in **insufficient neuromuscular blockade** for successful intubation. - Sub-therapeutic doses would lead to **incomplete muscle relaxation**, making intubation difficult and risky. *0.04 mg/Kg* - While higher than 0.02 mg/kg, this dose is still generally considered **sub-optimal** for intubation with pancuronium. - It may prolong the onset of action or provide **inadequate depth of block** for optimal intubating conditions. *0.06 mg/Kg* - This dose is approaching the lower end of an effective range for some neuromuscular blocking agents, but it is typically **not sufficient** for reliable intubation with pancuronium. - It might lead to a longer **onset time** and compromised intubating conditions compared to the recommended dose.

Question 1

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 2

Which anaesthetic agent is contraindicated in patients with emphysema?

Accepted Answer

Nitrous oxide (N2O)

Answer

Halothane

Answer

Diethyl ether

Answer

Isoflurane

Question 3

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

Accepted Answer

Ketamine

Answer

Morphine

Answer

Thiopentone sodium

Answer

Halothane

Question 4

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 5

IPPV can cause all of the following complications except:

Accepted Answer

Pulmonary embolism

Answer

Barotrauma

Answer

Pneumonia

Answer

Hypotension

Question 6

In infants, the narrowest part of the larynx is at the cricoid level. In administering anesthesia, which of the following is NOT a potential complication of using a smaller size endotracheal tube?

Accepted Answer

Choosing a smaller size endotracheal tube

Answer

Increased risk of airway obstruction

Answer

Trauma to the subglottic region

Answer

Choosing an inappropriate size endotracheal tube

Question 7

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

Question 8

What is the medical procedure that involves the insertion of a tube directly into the trachea to secure the airway and ensure adequate ventilation?

Accepted Answer

Endotracheal tube insertion

Answer

Oral suction

Answer

Oropharyngeal suction

Answer

Nasogastric tube insertion

Question 9

In which of the following conditions is Positive end-expiratory pressure (PEEP) beneficial?

Accepted Answer

Acute Respiratory Distress Syndrome (ARDS)

Answer

Pneumonia

Answer

Pulmonary edema

Answer

Chronic Obstructive Pulmonary Disease (COPD)

Question 10

What is the intubation dose of pancuronium?

Accepted Answer

0.08 mg/Kg

Answer

0.02 mg/Kg

Answer

0.04 mg/Kg

Answer

0.06 mg/Kg

Respiratory and Airway Management — MCQs

Respiratory and Airway Management — MCQs

On this page

Practice by Chapter

Want unlimited practice?