Following endotracheal intubation in an adult, where should the tip of the endotracheal tube (ETT) ideally be positioned on a chest X-ray?

1. A

   At the level of the carina

2. B

   2-3 cm above the carina

3. C

   In the right mainstem bronchus

4. D

   At the level of the sternal angle

Appeared in: NORCERT 8 Mains-2025

Explanation

Listen in Hindi

• The ideal position for an ETT is 2-3 cm above the carina, the point where the trachea bifurcates into the right and left main bronchi.
• This placement ensures that air delivered through the tube ventilates both lungs equally.
• It provides a safety margin, preventing the tube from entering a mainstem bronchus (especially during neck flexion) or being accidentally extubated (during neck extension).

Why Other Options Were Wrong

• Option A: Placing the ETT tip directly at the carina is too low. It can irritate this highly sensitive area, causing coughing and bronchospasm, and has a high risk of migrating into a mainstem bronchus with minimal patient movement.
• Option C: This describes a common complication, not the correct placement. Intubating the right mainstem bronchus leads to ventilation of only the right lung and causes the left lung to collapse (atelectasis).
• Option D: The sternal angle is an external anatomical landmark that corresponds to the level of the carina. Therefore, this option is functionally identical to placing the tube at the carina and is incorrect for the same reasons.

Related Visual

• Visual 1: Diagram - An illustration of the lower respiratory tract showing the trachea, carina, and main bronchi, with an ETT correctly positioned 2-3 cm superior to the carina.
• Visual 2: Chest X-ray - An annotated radiograph showing an ETT with its tip correctly positioned in the mid-trachea, well above the carina.
• Visual 3: Chest X-ray - An annotated radiograph demonstrating incorrect placement, with the ETT advanced into the right mainstem bronchus, leading to hyperinflation of the right lung and atelectasis of the left lung.

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Radiographic confirmation of endotracheal tube (ETT) placement as background academic context rather than a clinical decision trigger.
• A nurse's primary responsibility after intubation is to immediately assess for correct placement by auscultating for equal bilateral breath sounds and observing symmetrical chest rise, even before the chest X-ray is taken.
• Nurses must continuously monitor for signs of ETT displacement, such as changes in breath sounds, asymmetrical chest movement, or a change in the centimeter marking of the tube at the patient's lip.
• What if? If a post-intubation chest X-ray shows the ETT tip is 7 cm above the carina, the nurse should recognize this as being too high and increasing the risk of accidental extubation. The nurse should notify the respiratory therapist or physician to prepare for repositioning the tube.

How to Approach the Question

• First, identify the core of the question: finding the 'ideal' ETT position on a chest X-ray.
• Recall the relevant anatomy: the trachea is the main airway, and it divides at the carina into the right and left bronchi.
• Understand the primary goal of intubation: to ventilate both lungs. This means the tube must end in the trachea before it divides.
• Evaluate the options based on this principle. Placing the tube 'at the carina' or 'in a bronchus' would fail to ventilate both lungs safely or at all.
• Recognize that the 'sternal angle' is an anatomical landmark for the carina, making it an incorrect choice as well.
• Conclude that the only safe and effective position is a specific distance above the carina, which allows for a buffer for patient movement.

Concept Tested & Keywords

• Concept Tested: Radiographic confirmation of endotracheal tube (ETT) placement.
• Stem keywords: endotracheal intubation, adult, endotracheal tube, ETT, chest X-ray, position
• Lead-in keywords: where, ideally be positioned

Question ID

Q5hSmlelZ_meauw6L8VwTw

Copy ID