[ Vol. 9 No. 1 ] (January - April 2008 )
Safe, effective parenteral nutrition from the gactory to the vein, the role of the pharmacist

Patrick Ball
Professor of Pharmacy, Charles Sturt University, Wagga Wagga, Australia


In the early days of PN there was great excitement and enthusiasm. Multidisciplinary nutrition support teams (NST) were widespread, and a great deal of time and effort was expended to achieve the best possible outcomes from this expensive (but mostly cost-effective) therapy. Pharmacists have a role to play at every step.

Most patients were receiving individualised therapy, but many of these individual regiments did not have good stability data. There were also clinical incidents resulting from contamination in compounding units prompting moves to centre compounding in larger scale industrial units. These could provide better and more cost effective quality assurance, but were less responsive to patient needs. The ‘standard bag’ emerged and it was suggested that the needs of most patients could be adequately fed from only a small range of formulations.

In Europe and the USA, in the cost conscious 1980’s and 1990’s, many NSTs were disbanded and it has been argued that a ‘dumbing down’ of parenteral nutrition took place. Meanwhile enteral nutrition became more interventional and people seriously talked about the end of parenteral nutrition.

Parenteral nutrition is still life-saving, safe and cost effective, but only when performed to a high standard. Off the shelf standardized formulations are here to stay but they can and must be tailored and adapted to meet individual needs by dosage adjustment and minor customising. However, there will always be individuals who must have special formulae and it will be essential for countries to maintain the skill base and infrastructure to support this.

PN solutions are purchased from licensed manufacturers, but is remains important today to monitor transport cold-chain, in-house storage conditions, and during transport within the hospital to the patient. If additions need to me made (there are no nutritionally complete admixtures currently available), the additions must be made under suitable aseptic precautions and be of known stability and compatibility with the nutrition admixtures in use. The phrase coined by the Welsh Pharmacist, the late Dr Michael Barnett remains true; “no substitution (of products) without validation.”

A stable PN formula also requires safe administration. Concurrent parenteral therapy must be evaluated and safely co-administered. Pharmacists have a great deal to contribute if they take the time to learn and understand infusion equipment and devices. It is important to understand that, for example, if you co-administer antibiotics into a running infusion line, the position in the line at which it is added can make a profound difference to the plasma profile. For medications such as penicillins, which have only time-dependent killing of micro-organisms this will be of little consequence but for gentamicin which has concentration-dependent killing, the route of administration may make the difference between good effect or therapeutic failure. When multiple agents are co-infused, changing any one may unintentionally affect the delivery profile of the others. Pharmacists can become very skilled at managing these issues.

The venous access in use must be secured and kept free of infection and line patency maintained. Understanding the difference between the various types of circulatory access available and appropriate attention to the osmolarity of the solution and rate of delivery can prolong the life of an access route, especially if backed up by rigorous protocols for avoiding catheter infections.

Pharmacists understand that a ‘drug’ is actually administered as a formulated medicinal product, which may contain sugars, electrolytes, other excipients and a certain volume of water that may need to be included in calculations of daily fluid and electrolyte requirements. A number of medications also have significant interactions with nutrition.

Safe, effective PN requires attention to detail from start to finish, and the pharmacist has a role at all stages.


From The 12th PENSA Congress
October 18-20 2007
Century Park Hotel, Manila, Philippines
Page: 27-28