Minimal Enteral Nutrition Ramesh Agarwal, Rajiv Aggarwal, Ashok K. Deorari and Vinod K. Paul Division of Neonatology, Department of Pediatrics, All India Institute of Medical Sciences,Ansari Nagar, New Delhi, India. Abstract. Although parenteral nutrition has been used widely in the management of sick very low birth weight (VLBW) infants, a smooth transition to the enteral route is most desirable. Animal studies have shown that long periods of starvation are associated with mucosal atrophy and reduction of enzymatic activity. Studies have shown that giving small volumes of feeds frequently exerts atrophic effect on the gut mucosa. This concept has been termed as Minimal Enteral Nutriton (MEN). Clinical benefits of MEN include faster progression to full enteral feeds, lesser episodes of feed intolerance and reduction in hospital stay without a concomitant increase in the risk of necrotizing enterocolitis. MEN may be commenced in neonates on ventilation and total parenteral nutrition. A protocol for giving MEN has been described. [ Indian J Pediatr 2001; 68 (12) : 1159-1160] Key words : Enteral nutrition; VLBW infants; Neonates Ensuring adequate nutrition in preterm neonates plays an important role in their immediate survival and subsequent growth and development. Enteral and parenteral routes have been used for providing adequate nutrition to preterm neonates. Studies have shown that rapid enteral feeding may be associated with an increased risk of necrotizing enterocolitis (NEC). 1 Due to this concern, clinicians have relied on total parenteral nutrition (TPN) to deliver adequate calories to sick neonates in the initial few days. However, prolonged TPN is also associated with problems. Hence, a smooth and rapid transition from parenteral to enteral nutrition would be most desirable. PROBLEMS OF DELAYED FEEDING Animal studies have shown that prolonged periods of starvation are associated with thinning of the intestinal mucosa, villus shortening and reduction of enzymatic activity.2 Changes suggestive of gut atrophy have also been reported to occur within 34 days of stopping enteral feeds.3 In contrast, newborn animals fed for 48 hours after birth showed a 2-3 fold increase in intestinal mucosa mass as compared to those who were not fed. 4-6 This would suggest atrophic effect of enteral feeds on gut mucosa. It is possible that a prolonged delay in starting feeds in preterm neonates may be partly responsible for the common problems of feed intolerance encountered in these newborns. CONCEPT OF MINIMAL ENTERAL NUTRITION (MEN) This is a concept wherein minute volumes of feeds are given to the baby in order to exert atrophic effect on the intestinal mucosa. Studies have shown that neonates who Reprint requests : Dr. Rajiv Aggarwal, Assistant Professor, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110029.E-mail : rajivreema@hotmail.com were fed earlier with minimal feeds had lower episodes of feeding intolerance and gained weight faster as compared to neonates who were fed late.7-9These feeds are hypocaloric (adequate calories are not provided) and volumes ranging from 0.1 to 24 ml/kg/day have been used for minimal enteral nutrition. The practice of providing MEN for some period after birth is being developed as a strategy to facilitate gastrointestinal maturation in a way that would safely improve feeding tolerance and decrease time to reach full feedings. DEFINITION Minimal enteral nutrition (MEN) involves early initiation of low volume hypocaloric feeds in preterm neonates. Although MEN does not provide sufficient calories for growth, it is beneficial as it exerts atrophic effect on the gut mucosa. BENEFITS OF MEN Animal studies have shown a 2-3 fold increase in intestinal mucosa mass with early feeding. The trophic effect on intestinal mucosa may be mediated via various growth factors in human milk. These include insulin, epidermal growth factor and other peptides known to exert direct trophic effects. Breast milk has been shown to increase DNA synthesis in cultured fibroblasts. 1~ Besides the effect on intestinal mucosa, other beneficial responses to MEN include (a) muscle effects which include better peristaltic activity and coordinated motor activity in response to feeding. (b) vascular effects which include post-prandial decrease in splanchnic vascular resistance. This decrease would be associated with an increase in intestinal blood flow and oxygen uptake in response to feeding. (c) endocrine effects which include the release of various gastrointestinal peptides in response to feedingJ 1 Indian Journal of Pediatrics, Volume 68--December, 2001 1159