**Question:** Media commonly used for distension in hysteroscopy is: September 2011

**Core Concept:** Hysteroscopy is a diagnostic and therapeutic procedure in gynecology that involves visualizing the uterine cavity using a flexible endoscope called a hysteroscope. Distension is the process of filling the uterine cavity with a fluid to improve visualization and access during the procedure.

**Why the Correct Answer is Right:** The correct answer is "D" - Sodium chloride (NaCl) solution, also known as normal saline (NS). Normal saline is a widely used distension medium in hysteroscopy due to its isotonic nature, which maintains cellular integrity, and its ability to enhance visualization by minimizing tissue distortion and creating a homogeneous environment.

**Why Each Wrong Option is Incorrect:**

A. **Carbon dioxide (CO2)**: Although CO2 is commonly used for insufflation (inflating the uterine cavity) during hysteroscopy, it is not typically used for distension because it is hypertonic, causing tissue contraction and hampering visualization.

B. **Lactated Ringer's Solution (LR)**: Lactated Ringer's solution is also a hypertonic solution and can cause tissue contraction, making it an unsuitable choice for distension.

C. **Air**: Air is not a suitable distension medium for hysteroscopy as it does not maintain cellular integrity and can cause tissue distortion, impairing visualization.

**Clinical Pearl:**

Hysteroscopic procedures often involve the use of distension media, such as normal saline, to facilitate clear visualization of the uterine cavity and ensure safe and effective diagnosis and treatment. Adequate distension is essential for minimizing tissue distortion and maintaining cellular integrity.

**Correct Answer:** D. Normal Saline (NaCl)