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 startedDay PN was started

21

9

6

45

2

0

2

4

6

8

10

Mon Tues Wed Thurs Fri Sat* Sun

Nu

mb

er

of

Pts

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)

Any Questions