Presentation on theme: "Parenteral Nutrition in the Acute Setting Nikki Stewart Chief Dietitian North Herts. and Stevenage PCT."— Presentation transcript:
Parenteral Nutrition in the Acute Setting Nikki Stewart Chief Dietitian North Herts. and Stevenage PCT
PN The administration of nutrients via the intravenous route Usually with a dedicated central or peripheral line
Parenteral Nutrition Parenteral nutrition is generally started in order to prevent or minimise the adverse effects of malnutrition in patients who would other wise have no significant intake The length of time that a patient can tolerate complete or near starvation without harm is variable and unknown
Advantages of Parenteral Nutrition Meet calculated nutritional requirements in first 24 hours The feed can be tailored to meet estimated requirements High tech
Disadvantages Invasive Unphysiological - gut atrophy, bacterial translocation Cost - economic and clinical Risk of line insertion, subsequent infection and thrombophlebitus Risk of fluid and electrolyte imbalance
PN In patients with a failure in gut function(e.g.obstruction, fistula, ileus, dysmotility, severe malabsorption), to a degree that will definitely prevent gastro intestinal absorption of nutrients And The consequent intestinal failure has persisted for many days( e.g.>5 days) or is likely to persist for many days ( e.g.5 days or longer) before significant improvement
Long Term Indication for PN in Adults (BAPEN and NICE) Extreme short bowel syndrome Inflammatory bowel disease Radiation enteritis Motility disorders (Scleroderma) Chronic malabsorption
Short Term Indication for Parenteral Nutrition Prolonged NBM following major excisional surgery Multi - organ failure where nutritional requirements cannot be met by enteral route Severe pancreatitis Mucositis following chemotherapy High output or enterocutaneuos fistula Intractable vomiting
Other Requests for Parenteral Nutrition Veterans affairs study ( NEJ Med 1991) - complications associated with parenteral nutrition are least when used in severely malnourished patients for more than 5 days. Heyland et al JAMA 1998 (meta -analysis) studies published after 1989 suggest PN associated with increased mortality rates and no effect on complication rates. This could reflect the nutrient content of the feeds that predisposed patients to hyperglycaemia and infection.
Other Request for Parenteral Nutrition Mcfie BJS 2000 - when enteral route not working parenteral route preferred to starvation in catabolism, as patients left for >14 days have a poor outcome.
Parenteral Nutrition The decision to start parenteral nutrition is never an emergency. Catheter insertions should be planned and performed in aseptic conditions.
Audit In critical care – looking at requests for PN from 27/02/02 – 31/05/02 29 patients were started on parenteral nutrition 6 patients started on Thursday 9 patients started on a Friday 3 patients started at a weekend
Day PN was started
Audit 4 /9 started on Friday were fed for less than 4 days, 3 of these died 3 days later In that time 133 bags were prescribed 11 bags ( 8.3%) were wasted, 9 of which were for patients who died at the weekend
Outcome Plan for feeding all patients in critical care (including PN) discussed and agreed on a Friday. Where ambiguous, plan if not for PN clearly documented. For re-audit but anecdotally………..
NICE and Vitamins The addition of vitamins and trace elements are always required ……must be made under the appropriate pharmaceutically controlled conditions (NICE 2006) The common characteristics of these groups were a high oxidative tress and micronutrient depletion Heyland et al 2004
Revision on Thiamin Occurs most commonly as the coenzyme thiamine diphosphate (TDP)
Revision on Thiamin Coenzyme in many reactions in carbohydrate metabolism such as in the TDP dependent pyruvate dehydrogenase reaction to generate acetyl-CoA. (Key source of energy for mitochondrial oxidation and precursor compound in lipid metabolism) In the Krebs cycle TDP is a cofactor for oxidative decarboxylation of alpha ketoglutarate to succinyl CoA
Revision on Vitamin B6 Pyridoxal phosphate dependant enzymes catalyse a number of important reactions in amino acid and glycogen metabolism Transaminase to yield keto acids - the main route of oxidative metabolism of most amino acids, and provides a pathway for non essential amino acids, whose oxo acids are common metabolic intermediates
Revision of Vitamin B6 Decarboxylation to yield amines ( e.g.histamines) The process to synthesis niacin from tryptophan involving kynureninase Bender 1989 European Journal of Clinical Nutrition 10 – 20 % of the healthy population demonstrate signs of inadequate vitamin B6 intake. Plasma concentration also decreases with age
Role of Vitamin B6 Animal studies suggest 6 days are needed to return to normal enzyme activity
Revision of Vitamin C Anti oxidant Cofactor in hydroxylation reactions, deficiency results in impaired collagen synthesis Carnitine biosynthesis – from lysine. Carnitine is central to the role transporting long chain fatty acids in to mitochondria for oxidation and the supply of energy
Revision of Vitamin C Surgical stress has a marked effect on blood ascorbate levels (Schorah et al 1986 Annals of Clinical Biochemistry)
Trace Elements Selenium Vitamin E, Vitamin C function synergistically to regenerate both water and fat soluble antioxidants Providing a combination of endogenous antioxidant micronutrients improves clinical outcome more so than individual provision. Heyland 2005, Intensive Care Medicine
Case Report -Scolapio JPEN 2005 53 year old female with short bowel syndrome who developed urticaria after administration of cyclical PN 16 days after starting PPN noticed small hives and itching on arm which disappeared after 1 hour of stopping PN After eliminating individually drugs and drugs, established that it was related to the vitamin preparation
Case Report The reaction was related to the duration of the PN (day16 onwards) The rate of the PN infusion (182ml/hr) Thought to be related to the fact that a certain amount of allergen is required to trigger a reaction Oral preparation successfully used (stomach and 100cm of small intestine)