**1. Introduction**

Parenteral nutrition (PN) is a clinical nutrition strategy that provides patients with essential calories, macronutrients, and micronutrients needed for metabolic function through vascular access. PN is necessary in preterm babies and malnourished adult patients who are unable to feed, such as following gut trauma or general surgery, or in instances where the bowel requires rest under chronic inflammatory conditions. 'Parenteral' derives from the English *para* (beside) and ancient Greek *enteron* (intestine) and is usually administered via the central vein (jugular or subclavian vein). The formulation typically contains vital nutrients such as dextrose (D-glucose), amino acid cocktails, electrolytes, vitamins, tracer elements, and usually emulsified lipids in a hypertonic solution that is added just before

administration. When lipids are added, the term total parenteral nutrition (TPN) is applied. PN helps preserve lean body mass, supports immune functions, and reduces metabolic complications and oxidative stress in patients who are otherwise unable to consume and digest food by GI [1]. In the United States today, approximately 40,000 patients remain permanently dependent upon TPN and another 350,000 require transient PN for the treatment of or to prevent malnutrition [2]. Prior to the clinical use of PN, thousands of individuals developed severe malnutrition and while others starved when faced with GI failure.
