PARENTERAL NUTRITION IS THE MEDICAL TERM FOR INFUSING A SPECIALISED FORM OF FOOD INTRAVENOUSLY. SP LOOKS AT HOW THE TREATMENT CAN HELP TO CORRECT OR PREVENT MALNUTRITION


PARENTERAL NUTRITION: an inside job


by Debbie Orme, Editor P


arenteral nutrition (PN) provides liquid nutrients for people whose digestive systems either can’t absorb or can’t tolerate adequate food eaten by mouth.


This type of nutrition is extremely important since, if such people don’t get adequate nutrients by oral means, they can begin to experience malnutrition.


PN provides liquid nutrients, including carbohydrates, proteins, fats, vitamins, minerals and electrolytes intravenously. It is a sterile liquid chemical formula that is put directly into the bloodstream through an intravenous catheter, thereby bypassing the normal digestion in the gastrointestinal process. The intravenous nature of the feeding means that the person doesn’t have to ‘physically’ eat.


When it’s used outside of a hospital environment, the process is referred to as home parenteral nutrition (HPN). Patients may have to use HP for a period of weeks or months, but in some cases patients may have to use it for life.


44 - SCOTTISH PHARMACIST


HPN may be used in the short term if a person's digestive system has closed down and they are at a low enough weight to cause concern during, for example, an extended hospital stay. Long-term HPN, on the other hand, is occasionally used to treat people suffering the extended consequences of an accident, surgery, or digestive disorder.


Total parenteral nutrition (TPN) is provided when the gastrointestinal tract is not functioning due to a blockage or leak, or because its absorptive capacity is impaired in some way. In cases of TPN, a person’s taste, smell and physical fullness requirements are not being met and so, despite the fact that the body is being fully nourished, the patient experiences hunger.


TPN requires ten to 16 hours to be administered and so daily life can be greatly affected. Many types of pumps exist to limit the time that a patient is hooked up, with most using a backpack pump allowing for some mobility. While some patients will require one pump a day, others will require one five days a week.


Who requires HPN/TPN? People of all ages receive PN; indeed, it can be given to everyone from infants and children to the elderly. There are, however, certain cohorts of the population, who are particularly in need of this type of nutrition.


The elderly are obviously more prone to poor nutrient intake. For a start, they may have greater cardiac and renal impairment, or have deficiencies in vitamins and other crucial elements. Geriatric patients are also more inclined to have delayed muscle restoration in comparison with younger people.


With regard to elderly patients, PN is often indicated if oral or enteral nutrition is impossible for three days, or when oral or nutrition is assessed as insufficient for more than seven to ten days.


Cancer patients are also at a greater risk of malnutrition. This type of malnutrition is often attributed to the decrease in food intake, increase in the need for energy, and the alteration of metabolism. It’s for that reason that cancer patients are often


assessed early on in their treatment for nutritional risk. This assessment usually takes the form of routine weights and BMI.


When is PN required? Patients may need PN for any variety of diseases or conditions that impair food intake, nutrient digestion or absorption. While some patients may require this therapy for a short time, others may receive PN at home for a lifetime.


Among the conditions where PN is most frequently required are:


Crohn's disease


Crohn's disease is an inflammatory disease of the bowel that causes pain, bowel narrowing and other symptoms that affect food intake and its digestion and absorption.


Cancer


Cancer treatment – chemotherapy in particular – can cause the body to absorb nutrients poorly. Cancer of the digestive tract may also cause obstruction of the bowels, preventing adequate food intake.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48