**Question:** The following is true about endotracheal cuff. It has –

A. A non-compliant cuff made of rigid material (e.g., silicone) to prevent leakage
B. A compliant cuff made of soft material (e.g., silicone) that can change shape based on pressure applied
C. A cuff that is always filled to maximum pressure regardless of tube size
D. A cuff that is always filled with air regardless of patient's body size

**Correct Answer:** B. A compliant cuff made of soft material (e.g., silicone) that can change shape based on pressure applied

**Core Concept:**
An endotracheal tube (ETT) cuff is a component used in endotracheal intubation to prevent air leakage into or out of the trachea and lungs. The cuff's material and shape play a crucial role in maintaining its sealing ability.

**Why the Correct Answer is Right:**
The correct answer states that the cuff is compliant, meaning it is made of soft material (e.g., silicone) that can change shape based on the pressure applied. This allows the cuff to adapt to the tracheal contour, ensuring a better seal and preventing air leakage.

**Why Each Wrong Option is Incorrect:**
A non-compliant cuff (option A) would not be effective in conforming to the tracheal shape, leading to increased leakage and suboptimal airway protection.

A cuff filled to maximum pressure regardless of tube size (option C) may cause damage to the trachea due to excessive pressure and is not effective in ensuring proper sealing.

A cuff always filled with air regardless of patient's body size (option D) would also be ineffective in preventing air leakage, as the cuff size and pressure should adapt to the patient's tracheal dimensions.

**Clinical Pearls:**
1. The choice of cuff material (silicone) and its compliance allow the cuff to adapt to the tracheal contour, thus preventing air leakage and securing an optimal airway seal.
2. Properly inflating the cuff (usually around 20-30 cmH2O) ensures optimal sealing but avoids causing airways trauma.
3. The cuff size should be adjusted according to the size of the endotracheal tube to ensure an appropriate seal.
4. Regular cuff pressure checks are crucial to avoid airways trauma and maintain an effective seal.