Respiratory and Airway Management

Respiratory and Airway Management Indian Medical PG Question 1: Inhaled foreign bodies are more likely to get lodged in the right main bronchus because

• A. Right main bronchus is shorter, wider and nearly vertical (Correct Answer)
• B. Left main bronchus is wider and shorter
• C. Right main bronchus is shorter, narrower and lies horizontally in relation to trachea
• D. Left main bronchus is narrow and longer

Respiratory and Airway Management Explanation: ***Right main bronchus is shorter, wider and nearly vertical*** - The **anatomical configuration** of the right main bronchus makes it a more direct continuation of the trachea. - Its **wider diameter** and **more vertical angle** allow foreign bodies to fall into it more easily due to gravity and airflow. *Left main bronchus is wider and shorter* - This statement is incorrect; the **left main bronchus** is actually **narrower and longer** than the right. - Its **more acute angle** stemming from the trachea also makes it less likely for foreign objects to lodge there directly. *Right main bronchus is shorter, narrower and lies horizontally in relation to trachea* - This statement is incorrect as the **right main bronchus** is indeed **shorter** but is **wider** and takes a **more vertical** course, not horizontal. - The description of being "narrower" and "horizontally" contradicts the anatomical characteristics that facilitate foreign body impaction. *Left main bronchus is narrow and longer* - This statement is anatomically correct for the left main bronchus; however, these characteristics make it **less likely** for foreign bodies to get lodged here. - The **narrower lumen** and **longer path**, combined with a more acute angle, make it a less direct route for inhaled objects.

Respiratory and Airway Management Indian Medical PG Question 2: Which laryngeal cartilage is elastic?

• A. Cuneiform
• B. Epiglottis (Correct Answer)
• C. Corniculate
• D. Thyroid

Respiratory and Airway Management Explanation: ***Epiglottis*** - The **epiglottis** is the **largest** laryngeal cartilage composed of **elastic cartilage**, which allows it to be flexible and return to its original shape after bending. - This flexibility is crucial for its function in covering the laryngeal opening during swallowing, preventing food and liquids from entering the trachea. - It is the **most clinically significant** elastic cartilage of the larynx and the primary answer when asked about elastic laryngeal cartilages. *Corniculate* - **Corniculate cartilages** are small, paired cartilages also composed of **elastic cartilage** (not hyaline). - They are located at the apex of the arytenoid cartilages. - While elastic, they are much smaller and less significant than the epiglottis. *Cuneiform* - **Cuneiform cartilages** are also composed of **elastic cartilage** (not hyaline). - They are small, rod-shaped cartilages located within the aryepiglottic folds. - Like the corniculate cartilages, they are minor elastic cartilages compared to the epiglottis. *Thyroid* - The **thyroid cartilage**, the largest laryngeal cartilage overall, is composed of **hyaline cartilage**. - Its rigid structure provides protection for the vocal cords and forms the anterior wall of the larynx.

Respiratory and Airway Management Indian Medical PG Question 3: Which of the following procedures would be difficult to perform based on the given Chest X-ray?

• A. Tracheostomy (Correct Answer)
• B. Laryngeal mask airway insertion
• C. Ryle's tube insertion
• D. Intubation

Respiratory and Airway Management Explanation: ***Tracheostomy*** - The chest X-ray shows the presence of a **large thyroid mass** (appearing as a soft tissue density in the neck and upper mediastinum), which would displace the trachea and obscure anatomical landmarks, making a tracheostomy technically challenging and increasing the risk of complications. - A tracheostomy requires clear access to the anterior tracheal wall, which would be **directly obstructed** by the prominent thyroid hypertrophy visible on the X-ray. - This makes tracheostomy the **most difficult** procedure among the options, with significant risk of bleeding from engorged thyroid vessels and difficulty identifying the trachea. *Laryngeal mask airway insertion* - Laryngeal mask airway (LMA) insertion primarily involves placing a device over the **laryngeal inlet** and is not significantly affected by a mass lower in the neck impacting the trachea. - The LMA is a supraglottic device, and its placement does not require direct access to the trachea itself or the deeper structures of the neck. *Ryle's tube insertion* - Ryle's tube (nasogastric tube) insertion involves passing a tube from the **nose or mouth into the esophagus and stomach**. - This procedure is generally unaffected by a thyroid mass, as it primarily involves the gastrointestinal tract, which is anatomically separate from the trachea in the neck region. *Intubation* - Intubation (endotracheal intubation) involves placing a tube into the **trachea via the mouth or nose**, usually past the vocal cords. - While a large retrosternal thyroid mass can cause tracheal deviation and compression that may complicate intubation, it is generally **less difficult than tracheostomy** in this scenario. - Intubation can often be achieved with experienced anesthesia techniques (videolaryngoscopy, fiberoptic intubation), whereas tracheostomy faces direct surgical field obstruction by the thyroid mass itself. - The primary challenge for intubation is visualization and navigation past the vocal cords, not the direct anatomical obstruction at the surgical site that makes tracheostomy particularly difficult.

Respiratory and Airway Management Indian Medical PG Question 4: Which equation is used to calculate physiological dead space?

• A. Dalton's law
• B. Bohr equation (Correct Answer)
• C. Charles's law
• D. Boyle's law

Respiratory and Airway Management Explanation: ***Bohr equation*** - The Bohr equation is used to calculate **physiological dead space**, which is the sum of anatomical dead space and alveolar dead space. - It relates the partial pressure of carbon dioxide in arterial blood to the partial pressure of carbon dioxide in expired air, along with **tidal volume** and expired volume. *Dalton's law* - Dalton's law states that the **total pressure** exerted by a mixture of non-reactive gases is equal to the **sum of the partial pressures** of individual gases. - It is used to calculate partial pressures of gases in a mixture, not dead space. *Charles's law* - Charles's law describes the relationship between the **volume and temperature** of a gas at constant pressure. - It states that the volume of a given mass of gas is directly proportional to its absolute temperature. *Boyle's law* - Boyle's law describes the inverse relationship between the **pressure and volume** of a gas at constant temperature. - It is fundamental to understanding mechanics of breathing, but not dead space calculation.

Respiratory and Airway Management Indian Medical PG Question 5: What is the MOST clinically significant anatomical difference between pediatric and adult airways?

• A. Funnel-shaped vs cylindrical airway shape
• B. Proportionally larger tongue
• C. Larynx in higher position
• D. Narrowest part is cricoid cartilage (Correct Answer)

Respiratory and Airway Management Explanation: ***Narrowest part is cricoid cartilage*** - In **pediatric airways**, the **cricoid cartilage** is the narrowest point, making it the **most critical consideration** for endotracheal tube sizing and intubation. - This contrasts with adults where the **glottic opening** (vocal cords) is typically the narrowest. - This difference is **clinically crucial** as it determines tube selection, risk of subglottic stenosis, and why uncuffed tubes were traditionally preferred in children. *Proportionally larger tongue* - Pediatric patients indeed have a **proportionally larger tongue** relative to their oral cavity, which can contribute to airway obstruction [1]. - While this is a true anatomical difference, it is **less critical** for intubation decisions than the cricoid narrowing. *Funnel-shaped vs cylindrical airway shape* - Pediatric airways are **funnel-shaped** with narrowing at the cricoid, whereas adult airways are more **cylindrical**. - This morphological difference is a **consequence** of the cricoid being the narrowest point, not a separate primary consideration. *Larynx in higher position* - The **larynx** in infants and young children is positioned more **superiorly** (C3-C4 vs C4-C6 in adults). - While this affects intubation technique and angle, it is **less directly relevant** to airway sizing than the cricoid narrowing.

Respiratory and Airway Management Flashcard 1 of 5

Question: Nasal cannula, non rebreathing mask, and nasal mask are _____ flow variable performance systems

Answer: low

Respiratory and Airway Management Flashcard 2 of 5

Question: Airway is secured in laser airway sx using cuffed silicone or rubber based ET tubes filled with _____

Answer: saline

Respiratory and Airway Management Flashcard 3 of 5

Question: _____ airway is also known as Guedel airway

Answer: Oropharyngeal

Respiratory and Airway Management Flashcard 4 of 5

Question: Initial ventilatory settings are started as PEEP of _____ cm of H2O and titrated slowly to 10 cm H2O

Answer: 5

Respiratory and Airway Management Flashcard 5 of 5

Question: Tidal volume mechanical ventilation

Answer: Tidal volume mechanical ventilation