Peripheral Intravenous Nutrition Therapy: Outpatient, Office-Based Administration

Alternative Medicine Review, August, 2000 by Ian D. Bier

Abstract

BACKGROUND: The use of peripheral intravenous nutrition (PIN) has been growing in recent years due to the increase in awareness of the pathophysiological mechanisms of peripheral vein thrombophlebitis, as well as the availability of techniques to prevent or retard its onset. With the increase in public and medical practitioner awareness of the importance of nutritional interventions in health and disease, more outpatient-based PIN therapy is being performed. Outpatient, office-based PIN has unique features including high osmolality, high infusion rates, and short infusion duration. METHODS: Previous intravenous nutrition studies were used to estimate safety parameters for outpatient, office-based PIN. CONCLUSIONS: Osmolalities of the infusion can approach 1000 mOsm/L if the duration of the infusion is only several hours. The infusion should be diluted to reduce the osmolality, even if an increase in infusion rate is necessary. Duration of infusion should be less than three hours to reduce the time the irritating mixture contacts the vein wall. This requires high (150-330 mL/hour) infusion rates. The largest vein, and smallest and shortest catheter possible to achieve the infusion rate desired should be used, with in-line filtration of at least 0.45mm. The cannula should be removed at the first sign of pain or redness. Standard procedures to reduce infection risks should be followed.

(Altern Med Rev 2000;5(4):347-354)

Introduction

It has been estimated that 40 percent of all drugs administered in hospital settings is through injection.[1] Although indications for total parenteral nutrition (TPN) are diminishing as basic science and clinical studies continue to find increased benefits associated with enteral feeding, and as techniques for initiating enteral nutrition improve,[2] it remains in wide use, with 10 percent of ICU days using TPN.[3] The field of drug pharmacology and hospital-based intravenous administration is well researched, with tens of thousands of articles in the medical literature. Safety parameters including insertion site,[4-10] infusion rate,[11-20] osmolality of solution,[21-29] and time in situ[6,30-33] are well explored for hospital-based pharmaceutical and TPN infusions. However, safety parameters for outpatient, office-based peripheral intravenous (IV) nutrition infusions have not been explored in the literature to date.

With a substantial and rapid increase in the use of alternative medicine over the last decade, the focus of alternative medicine on proper nutrition, and the wide availability of pharmacological nutrient preparations for intravenous infusion, it is logical to assume the number of outpatient, office-based peripheral intravenous nutrition (PIN) infusions is increasing. Therefore, it is expedient to define safety parameters for office-based nutritional infusion therapy.

Most hospital infusions are delivered over a 12-24 hour time span because of patient around-the-clock availability, thus allowing a slower infusion rate but requiring longer retention of the catheter. In outpatient-based therapy, infusion rates are necessarily accelerated; therefore, the rate the infused solution comes into contact with the venous wall is increased. These differences may reduce some of the concerns regarding PIN, while increasing others. Risks of infection and septicemia have been correlated with infusion duration[5] and may be reduced in an in-office setting due to the decreased indwelling time of the catheter. Reductions in the risk of extravasation, catheter dislodgment, and occlusion would also be expected, due to the decreased time in situ. Additionally, there is a reduced need for patient movement while the line is inserted due to the short treatment time.

Complications of PIN include infection, phlebitis and thrombophlebitis, venous spasm, venous irritation, emboli, pain, hematoma or hemorrhage, extravasation, arterial cannulation, and needlestick injury.[34,35] Certain complications, such as venous irritation, venous spasm, and thrombophlebitis may exhibit an increased risk compared to hospital-based infusion due to the more rapid infusion rate. A slower infusion rate allows the admixture to dilute in a larger volume of blood, while a faster rate decreases dilution, allowing a possible osmotic or irritating component to more fully contact the venous wall.

One of the most common risks of intravenous therapy is phlebitis,[36,37] affecting almost 100 percent of patients in some studies.[22,38,39] Phlebitis causes severe discomfort in the affected limb, causing the vein to become red, swollen, and hardened.[35] Interruption of the therapy becomes necessary and a new site must be started.[40] Proper techniques of IV administration are well covered in many basic texts, and therefore will not be covered in this paper.

Thrombophlebitis is a thrombus within a vein with accompanying inflammation. The thrombus is initially composed of platelets and fibrin which then becomes interspersed with red blood cells. The inflammatory response in the vein is characterized by granulocyte infiltration, loss of endothelium, and edema. The symptoms of acute thrombophlebitis arise over a period ranging from hours to one or two days. The disease process is usually self-limited and lasts between one and two weeks, then the acute process subsides and painful symptoms disappear. Chemical phlebitis results from intimal injury induced by the introduction of catheters or noxious agents directly into a vein.[43]