## **Core Concept**
The question revolves around the management of a newborn with a lumbosacral meningomyelocele, specifically focusing on the protection of the sac before surgical repair. Meningomyelocele, a form of spina bifida, involves the protrusion of the spinal cord and meninges through a defect in the vertebral column. The goal is to prevent infection and further injury to the exposed neural tissue.

## **Why the Correct Answer is Right**
The correct answer involves using a sterile gauze piece soaked with **normal saline**. This method helps keep the sac moist, reducing the risk of desiccation and subsequent infection or damage to the neural tissue. Normal saline is isotonic and does not irritate the tissues, making it an ideal choice for maintaining the viability of the exposed spinal cord and meninges until surgical intervention can occur.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Sterile water could cause hypotonicity and potentially disrupt the cellular environment, but it's not the primary concern here; the main issue is the lack of electrolytes.
- **Option B:** **Betadine (povidone-iodine)** solution is not suitable because iodine can be toxic to neural tissue and might interfere with thyroid function if absorbed in significant amounts. Moreover, its use on open neural tissue is generally avoided due to potential toxicity.
- **Option C:** **Gentian violet** is an antiseptic but is not typically used for keeping tissues moist. It's also not the best choice for neural tissue exposure due to potential toxicity.
- **Option D:** While not explicitly listed, any solution not isotonic or potentially toxic to neural tissue would be incorrect.

## **Clinical Pearl / High-Yield Fact**
A crucial point to remember is that the management of meningomyelocele involves careful protection of the sac to prevent infection and further injury. Keeping the sac moist with **sterile normal saline-soaked gauze** is a recommended practice. Immediate surgical repair is often planned, but until then, maintaining the integrity of the exposed tissue is vital.

## **Correct Answer:** . Normal saline.