Uninterrupted perioperative enteral nutrition.

Key words: Enteral feeding; enteral nutrition; uninter-rupted enteral nutrition; perioperative feeding; tubefeeding; perioperative complications; perioperativesepsis; infections, immune modulation; intestinal secre-tion; intestinal motility; micronutrients; antioxidants;polyunsaturated fatty acids; feeding tubes; auto-posi-tioning feeding tubes; self-propelling feeding tubes;gastrointestinal mucosa; gastrointestinal secretions;natural food ingredients; burns; acute pancreatitis;surgeryIntroductionSince the introduction of inhalation anaesthesia,patients have been required to fast for 12–18h beforesurgery. Similarly, oral and enteral feedings are stilloften avoided for the ﬁrst days after surgery. The mainreason for preoperative fasting is to avoid vomiting onthe introduction of anaesthesia. Also, it was generallybelieved that the gastrointestinal tract is paralysedduring the ﬁrst few days after trauma or surgery, whichis why enteral feeding was avoided during the ﬁrstpostoperative days. However, this seems to be true onlyfor the stomach and partly for the colon. Becausemotility remains in the small intestine and to someextent also in the colon, an uninterrupted enteral supplyof nutrients should almost always be technicallypossible, at least if enteral feeding tubes are used tobypass the paralysed stomach. The aim of this review isto discuss why discontinuation of enteral nutritionin connection with operation might be disadvantageousto outcome and to suggest a more intensive policy:uninterrupted perioperative enteral nutrition.Lack of nutrition has several immediate negativeconsequences: 1) inhibition of saliva and digestive tractsecretions, 2) inhibition of GI motility and splanchniccirculation, 3) increased virulence of the subﬂoraof potentially pathogenic microorganisms, 4) reductionand inhibition of the protective ﬂora, 5) atrophy of themucosa of the small intestine and colon, 6) increasedmicrobial translocation, and 7) reduced supply ofimportant antioxidants, ﬂavonoids, phytoestrogens,and other important factors, currently known or stillunknown, that may inﬂuence the rate and severityof postoperative and post-trauma sepsis.The most obvious and immediate consequenceof short malnutrition is no doubt sepsis. But theimportance for the wellbeing of the patient of awell-functioning gut, and the role of the gut in theprevention of infection, has not been su†cientlyrecognized. Oral, but also enteral feeding, stimulatesgastrointestinal secretion. The importance of saliva (1)and the other external secretions, such as pancreatic andintestinal juices, in supplying factors of importance forthe luminal humoral immune system has also not beensu†ciently considered. Although Besredka (2) identiﬁedthe importance of local immune defence around 1920,responsible immunological factors such as immunoglo-bulin were not isolated and characterized until the late1950s, ﬁrst in mothers’ milk and later in most externalsecretions.Today it is well known that that most of the body’sIgA is produced by the gut. The importance of acontinuous supply of nutrients not only to feed theprotective ﬂora, but also the potentially pathogenicintestinal ﬂora, has also not been su†ciently recognized.The protective ﬂora are often reduced as a resultof diseases, aggressive treatment with pharmaceuticals,including antibiotics, and lack of nutrients, and ﬂorawhich might remain need to be stimulated througha supply of enteral nutrients and/or supplementedthrough external supply of probiotics. Pasteur andJoubert (3) recognized long ago the phenomenon ofbacterial antagonism, which is the basis for the under-standing of the role of the preventive ﬂora, andMetchnikoﬀ (4) suggested in the early 1900s an activebacterial replacement therapy. However, it took almosta full century before microbial interference was acceptedas an important concept in infection control (5). Infections: the main obstacle to success of hospital careGut-derived opportunistic infections constitute the mainsource of infection in trauma, pancreatitis, and burns,but also in patients with human immunodeﬁciency virus,inﬂammatory bowel disease, and many other conditions.It was recently been pointed out by Schwartz (6), that