The Perioperative Nutrition Screen (PONS) is a brief preoperative screening tool used to identify patients who may be at nutritional risk before surgery. It was introduced as a rapid way to flag patients who may need fuller nutrition assessment and possible nutrition optimization before an operation.

PONS is based on four main risk areas:

• Low BMI
• Recent unintentional weight loss
• Reduced recent oral intake
• Low preoperative albumin

In the commonly used description, the screen is positive when one or more of these criteria are present, with thresholds such as BMI <18.5 kg/m² if age 65 or younger, or <20 kg/m² if older than 65, more than 10% unintentional weight loss in 6 months, eating less than 50% of normal in the past week, or albumin <3.0 g/dL.

Why it matters: preoperative nutrition risk is associated with worse postoperative outcomes, and PONS is meant to help teams identify those patients early so they can consider dietitian review or nutrition support before surgery.

So in plain language, PONS is a quick surgery-related malnutrition risk screen, not a diagnosis by itself. A positive screen means the patient may benefit from further nutritional assessment and optimization before surgery.