CLINICAL KNOWLEDGE Management and effects of parenteral nutrition

Author Angie Davidson, MSc, RN, DipHE Nursing nutritional support. The need for effective communica­ Studies, CertSupervisory Management, tion between all levels of health care professionals is CertPsychodynamic Counselling, is nurse consultant even more crucial (Hudson, 2000). in nutrition and intestinal failure, North West London Hospitals NHS Trust. What is it? Abstract Davidson, A. (2005) Management and Parenteral nutrition, otherwise known as intravenous effects of parenteral nutrition. Nursing Times; 101: nutrition (IVN) is the intravenous infusion of 42, 28-31. that are pharmaceutically compounded in a large References Despite nutrition being a basic human need, collapsible bag (Pennington, 2000). malnutrition in hospitals remains surprisingly The various terms for parenteral nutrition that have BAPEN (1996) Current procedures common, with the effects clearly documented been used within the literature are somewhat on parenteral nutrition in adults. (Taylor and Goodison-McLaren, 1992). Malnourished confusing. Total parenteral nutrition (TPN) refers to the Redditch: BAPEN. patients are more likely to suffer from exclusive administration of all nutritional requirements Cottee, S. (1995) Heparin lock complications; are at increased risk of developing via the intravenous route. Supplemental parenteral practice in total parenteral nutrition. infections; have poor or delayed wound healing, nutrition (SPN) refers to the administration of some Professional Nurse; 11: 1, 25–29. increased mortality rates and longer hospital stays. element of the required nutritional requirements, with This article focuses on the basics of parenteral other components being met via enteral absorption. Dickerson, N. et al (1989) in the adult, addressing a small selection These terms may lead to confusion and, although total significance central venous of potential complications. parenteral nutrition (TPN) is the most commonly used infections in a community hospital: terminology, parenteral nutrition is preferred. associated with type of dressing. Nutrition support teams (NST) evolved to promote Journal of Infectious Diseases; nutrition as a positive therapy for hospital patients to Why is it given? 160, 720–721. reduce the incidence of malnutrition. The multi­ Parenteral nutrition is needed when the intestine Drewett, S. (2000) Complications of disciplinary NST provides specialist services that cannot be used or cannot absorb or digest adequate central venous : nursing facilitate the development of protocols, standards, amounts of nutrients temporarily or permanently. As care. British Journal of Nursing; research, education and quality assurance (Hudson, enteral feeding or using the oral route is cheaper, 9: 8, 466–478. 2000). The British Association for Parenteral and safer and associated with physiological advantages, Enteral Nutrition (BAPEN) has published specific parenteral nutrition should only be considered if full guidelines regarding setting up such teams (Silk, 1994). requirements are not able to be met by these safer, Unfortunately not every trust has nutrition as a more natural methods. Even after intestinal surgery positive treatment at the top of their agenda or has when gastric motility may not have fully returned, the resources to fund such an initiative. In centres there is evidence that small bowel function returns such as these where there is no formal team earlier and could be utilised in nasojejunal feeding or identified, effective leadership is crucial to providing feeding via a surgically placed to avoid use of parenteral nutrition (Pennington, 2000). Conditions in which parenteral nutrition is Learning objectives commonly used in adults can be seen in Box 1.

Each week Nursing Times publishes a guided learning article with reflection How is it given? points to help you with your CPD. After reading the article you should be able to: Once the patient’s nutritional requirements are calculated, nutrients, electrolytes, , trace elements and can be infused using an infusion l Understand what parenteral nutrition is; pump through a (CVC) or a cannula. Ideally a dedicated single lumen device is l Know why parenteral nutrition is given; desirable as complications of catheter-related and blockage can be minimised. l Be familiar with how enteral nutrition is given; However, it is likely that acutely unwell patients will l Understand the potential complications of parenteral nutrition. require other infusions and therapies and, in these cases, the use of multi-lumen catheters is essential. If

multi-lumen catheters are used, it is important that SPL

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Box 1. Conditions that may require nutrition for the foreseeable future, such as in References parenteral nutrition complex intestinal failure, a structured approach is essential in order to plan which veins are to be Hamilton, R.A. et al (1988) Heparin sodium versus 0.9% sodium chloride Prolonged paralytic cannulated and in which order. This will promote the preservation of veins over the longer term in the hope for maintaining patency of Severe indwelling intermittent infusion of maintaining lifelong . devices. Clinical Pharmacology; Trauma involving viscera The most appropriate site for patients requiring 7: 6, 439–443. Major sepsis long-term parenteral nutrition is the subclavian vein, with the catheter subcutaneously tunnelled onto the Severe burns Hamilton, H. (2000) Choosing the chest wall so the catheter exits the patient at a point appropriate catheter for patients Mucositis away from the bloodstream to reduce the incidence of requiring parenteral nutrition. Intestinal failure, which can include: bloodstream infection. Siting the catheter in this way In: Hamilton, H. (ed) Total can provide the patient a clear view of both the Parenteral Nutrition: A Practical l device and exit site, making aseptic manipulations Guide For Nurses. London: l Gastrointestinal fistulae easier and helping build patient confidence. Box 3 Churchill Livingstone. (p31) provides an overview of the types of device. l Radiation enteritis Hoffman, K.K. et al (1992) The insertion of a central venous device should only l Severe inflammatory bowel disease Transparent polyurethane film as an be undertaken by an operator experienced in gaining intravenous catheter dressing. l Motility disorders, such as visceral myopathy central venous access. It should be carried out in an Journal of the American Medical environment with an appropriate level of cleanliness Association; 267, 2072–2076. and facilities for screening to aid insertion and confirm one lumen be dedicated to parenteral nutrition to catheter tip position as being low in the superior vena Hudson, J. (2000) The ensure minimisation of contamination and that an cava or right atrium, once the device is in place. multidisciplinary team. In: Hamilton, equal level of asepsis be applied to all lumens In centres where there is an established nutritional H. (ed) Total Parenteral Nutrition: A Practical Guide For Nurses. London: (Hamilton, 2000). If using a single-lumen device, support team providing a parenteral nutrition service, Churchill Livingstone. routine sampling and additional infusions it is likely that there will be an identified experienced should be carried out independently, using a separate operator or team of operators adopting a standard Kyle, L.A., Turner, B.S. (1999) cannula if necessary. insertion method and using standardised equipment Efficacy of vs heparin in In choosing a device, there are many different types as defined with a multidisciplinary care protocol. maintaining 24 gauge intermittent of device or cannula to suit the type and duration of Following insertion, it is important that the patient’s intravenous catheters in a rabbit therapy and it is important that each patient’s needs vital signs are monitored to detect any complications model. Neonatal Network; are assessed individually. Points for consideration in related to central venous catheterisation, including 18: 6, 49–54. choosing a device can be seen in Box 2 (p30). , arterial puncture, , The type of device to be used and the insertion cardiac tamponade, infection, catheter misplacement Le Duc, K. (1997) Efficacy of normal saline solution versus heparin method will usually be determined by the planned and neurological damage (Drewett, 2000). The solution for maintaining patency of duration of therapy and venous access status of the frequency and duration of will depend on peripheral intravenous catheters in patient. Parenteral nutrition given over a short period the condition of the patient and local policy. children. Journal of Emergency such as one or two weeks, can often be successfully Parenteral nutrition will usually be prescribed to run Nursing; 4, 306–309. administered using a peripheral cannula or by using a continuously over a 24-hour period initially. Again, it is peripherally inserted central catheter (PICC) to gain important that vital signs, fluid balance, blood , central venous access using a peripheral vein. Due to weight and blood biochemistry be closely monitored the potential problems of thrombophlebitis, strict with feed volume and/or components adjusted aseptic technique at insertion and all manipulations of accordingly. If blood glucose levels remain below the cannula is essential if peripheral parenteral 10mmol/l after the initial 24–48 hours, daily urinalysis nutrition therapy is to be successful. Once enteral should be sufficient. intake is established, or if there are problems such as Providing the patient remains physiologically stable thrombophlebitis causing pain and inflammation of on the regimen, the rate of infusion can gradually be the peripheral vein, the cannula can be promptly and increased each day to allow ‘free time’ from the easily removed and the patient’s needs reassessed. infusion and all its paraphernalia. For those requiring For longer-term parenteral nutrition therapy, a longer periods of time attached to their infusion, such central venous catheter is inserted into one of the as in complex intestinal failure where the infusion central veins – typically the subclavian and jugular volume can reach several litres in a 24-hour period, an veins or, if gaining venous access is a problem due to ambulatory pump can be used. This offers the patient previous central venous catheterisations, venous increased mobility while attached to the infusion. It is This article has been double-blind thrombosis or damage making future cannulation of important to note that, although this level of monitoring peer-reviewed. the same vein impossible, the femoral veins can be is essential in the acutely ill patient, it should not be For related articles on this subject used (Hamilton, 2000). necessary in the long-term, physiologically stable, and links to relevant websites see If it is felt that a patient will need parenteral home parenteral nutrition patient. www.nursingtimes.net

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References Potential complications Box 2. Device selection – factors to Catheter-related sepsis is the most common type of consider (BAPEN, 1996) Little, K., Palmer, D. (1998) Central complication associated with central venous devices line exit sites: which dressing? and parenteral nutrition administration and should be l Duration of therapy Nursing Standard; 12: 48, 42–44. a patient care priority for any health care professional. l Multi or single lumen A definition of catheter-related sepsis is a ‘clinical Madeo, M. et al (1997) A picture of spiking fever and chills resulting from blood l Cuffed or uncuffed randomized study comparing IV 3000 (transparent polyurethane passage of micro-organisms from an intravascular l Implantable or external device infusion system. Isolation of the same organism from dressing) to a dry gauze dressing for l Patient experience peripheral intravenous catheter blood and catheter segments is considered definite sites. Journal of Intravenous proof’ (Sitges-Serra et al, 1985). l Patient’s ability to perform self-care Nursing; 20: 5, 253–256. Typical clinical symptoms can include pyrexia l Gauge of catheter greater than 38°C and rigors that begin soon after the l Method of catheter removal Pennington, C.R. (1999) Current infusion starts and subside when the infusion is Perspectives on Parenteral stopped. It is important to remember, however, that l Catheter material Nutrition in Adults. this is the most common presentation of a catheter- l Redditch: BAPEN. Cost related infection. Many patients do present differently, Pennington, C. (2000) What is for example with lower-grade pyrexia, feeling parenteral nutrition? In: Hamilton, H. generally unwell and pyrexia when the patient is not cost-effective and can result in a reduction in nursing (ed) Total Parenteral Nutrition A being infused, and need to be individually assessed. time required (Shivnan at al, 1991). Practical Guide For Nurses. London: Infections can be external to the catheter initially The catheter infection rate within the clinical area is Churchill Livingstone. such as in an exit site infection (erythema, tenderness, influenced largely by the level of education and induration or purulence within 2cm of the at the training of health care professionals and patients. Randolf, A.G. et al (1998) Benefit of exit site of the catheter) or tunnel infection (erythema, Research evaluating products and procedures has, heparin in peripheral venous and tenderness and induration in the tissues overlying the unfortunately, been relatively small and inconclusive, arterial catheters: systematic review catheter and greater than 2cm from the exit site) which has led to much confusion and vast variation in and meta-analysis of randomised (Scottish HPN Group, 2002). If left untreated, micro- practice (Sherliker, 2000). Health care professionals trials. British Medical Journal; 316: 7136, 969–975. organisms can track along the catheter or can seed should, therefore, analyse the available data to the catheter from cross-contamination. develop care protocols that give guidance on all Scottish HPN Group (2002) Scottish The optimal dressing for the exit site remains aspects of catheter care from handwashing to Home Parenteral Nutrition controversial. The dressings commonly used are sterile managing catheter-related sepsis. Managed Clinical Network – gauze dressings and transparent occlusive dressings. Device patency is essential in the management of Catheter Care Procedures and Some studies have reported an increased rate of the patient receiving parenteral nutrition, and flushing Protocols for the Patient on Home infection associated with the use of transparent the device is vital in the prevention of complications Parenteral Nutrition. dressings. It is thought that this could be due to an such as catheter occlusion. There are many factors Dundee: Ninewells Hospital and increase of moisture at the exit site (Hoffman et al, that may lead to occlusion of the catheter (Scottish Medical School. 1992; Dickerson, 1989), although other studies have HPN Group, 2002), including: found this not to be the case, showing no statistical l Poor positioning of the catheter; difference in rates of infection between transparent or l A kink in the catheter; gauze dressings (Little and Palmer, 1998; Madeo at al, l The formation of a fibrin sheath at the tip of the 1997). It has been suggested than transparent catheter can act as a one-way valve, allowing saline occlusive dressings are preferred by the patient, are to be flushed but preventing the withdrawal of blood; l Fibrin deposits caused by the formation of a clot due to stagnant blood left in the catheter lumen; Guided reflection l sludge caused by lipid deposit formation; l Drug precipitation. Use the following points to write a reflection for your PREP portfolio: There remains much debate as to what the catheter should be routinely flushed with to maintain patency. l Explain how this article is relevant to a patient in your clinical area; A survey by Cottee (1995) was carried out to determine the current practice for maintaining l Highlight the key points the article makes; catheter patency in the UK. Although the majority used heparin solution, concentrations varied from l Outline something new you have learnt about parenteral nutrition; 1 unit per ml to 5000 units per ml, and the volumes used varied from 1ml to 5ml. While it is considered l Consider how you could use this information in the care of a patient; that the use of heparin is harmless, complications such as drug interactions, thrombocytopenia and thrombo­ l Outline how will you follow up what you have learnt. sis syndrome have been reported with the use of heparin flushes, and several studies have indicated

30 NT 18 October 2005 Vol 101 No 42 www.nursingtimes.net Box 3. Devices suitable for parenteral nutrition administration References

Silk, D.B.A. (1994) Organisation of Peripherally inserted These can be manufactured from PVC or silicone rubber, covering a Nutritional Support in Hospitals: variety of lengths and gauges. Nutrition Steering Committee and Nutrition Support Teams – Needs, Structure and Roles. Short term These may be manufactured from rigid material, such as Teflon, Redditch: BAPEN. and are intended to remain in position for several days only, or from softer polyurethane, which may remain in place for several Sitges-Serra, A. et al (1985) weeks. They are most commonly used during major surgery or Catheter sepsis: The clue is the hub. cardiopulmonary . Surgery; 97: 3, 355–357.

Long term These are generally manufactured from polyurethane or silicone Sherliker, L. (2000) Complications. rubber. The smooth material reduces the risk of abrasion to the In: Hamilton, H. (ed) Total veins and such catheters can be left in position for much longer Parenteral Nutrition: A Practical Guide For Nurses. London: periods. Silicone rubber and polyurethane catheters are available Churchill Livingstone. in various forms to meet clinical need.

Shivnan, J.C. et al (1991) A Single lumen This is the most commonly used long-term central venous catheter. comparison of transparent adherent Some require external sutures to anchor them in position. Others and dry sterile gauze dressing for incorporate a small cuff, which is positioned just beneath the skin. long term central catheters in patients undergoing bone marrow Epithelialisation anchors the catheter to the subcutaneous tissue transplant. Oncology Nursing within 14–21 days, when the external sutures may be removed. Forum; 18: 1349–1356.

Taylor, S., Goodison-McLaren, S. Multi-lumen Double, triple or quadruple lumen catheters are available to (1992) Nutritional support: facilitate the concurrent administration of fluids, drugs, blood and a team approach. London: the recording of central venous pressure. The individual lumens are Wolfe Publishing. separated for the full length of the catheter.

Totally implanted ports These are used for prolonged venous access, particularly when only intermittent therapy is required. In place of an external segment, the catheter ends in a lightweight titanium or epoxy resin incorporating a thick silicone disk, which lies just beneath the skin. Access to the venous system is achieved by inserting a non-coring needle through the skin and disk into the port.

that there is no significant difference between flushing that despite over three decades of use, substantial peripheral catheters with sodium chloride or heparin gaps in the evidence base still exist. The development (Kyle and Turner, 1999; Randolf et al, 1998; LeDuc, of evidence-based multidisciplinary care protocols that 1997; Hamilton et al, 1988). Catheters should, cover every aspect of parenteral nutrition however, be flushed using syringes no smaller than administration, preparation of the patient, 10ml because they exert greater pressure, which in a examination, monitoring and long-term management partially occluded device could rupture the material. of the central venous device are essential in Fibrin deposition within the lumen of the catheter minimising the risk of complications (Hamilton, 2000). can be cleared with the administration of urokinase. BAPEN has publications relating to many different Drug precipitation and lipid deposition can be treated aspects of artificial nutrition support administration with ethanol or hydrochloric acid. Again, there is no that can be referred to (Pennington, 1999). In clear evidence-based guidance on dosage, Scotland, a network of hospitals has successfully concentrations or dwell times, and more research is standardised care through the development of a needed so that patency can be more effectively managed clinical network. In England, work is being maintained and problems dealt with promptly using carried out between the two national centres of the correct treatments (Scottish HPN Group, 2002). excellence for intestinal failure (St Mark’s Hospital, Parenteral nutrition is a safe, effective and life- London and Hope Hospital, Salford) and the National saving therapy if monitored and managed appropriately Nurses Nutrition Group (NNNG) in the development of with a multidisciplinary approach. It is clear, however, national guidelines for parenteral nutrition. n

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