Ezra Steiger MD

Contents

1 Introduction

2 Venous Access Devices for Parenteral Nutrition

3 Venous Access in Patients with a Major Vein Thrombosis

4 Complications

5 Conclusion

Summary

Safe and effective vascular access is an important part of any program of parenteral nutrition. An appropriate vascular access device that is well placed and positioned will help to minimize complications associated with its use. The early recognition and treatment of device malfunction and complications associated with prolonged used will decrease any associated morbidity and mortality.

Key Words: Central parenteral nutrition, Peripheral parenteral nutrition, temporary vascular access, Permanent vascular access, Tunneled catheters, Subcutaneous ports, Peripherally inserted central catheters (PICC), Catheter occlusion, Catheter associated thrombosis, Catheter-related blood stream infection (CRBSI)

From: Clinical Gastroenterology: Nutrition and Gastrointestinal Disease Edited by: M.H. DeLegge © Humana Press Inc., Totowa, NJ

1. introduction

The ability to obtain and maintain prolonged safe venous access allows the infusion of hypertonic nutrient solutions into patients requiring parenteral nutrition (PN) and is an essential element for the success of intravenous feeding [1]. The history of developments in the area of vascular access spans several centuries. The use of central venous access for PN in the hospital setting was first reported in the late 1960s and at home in the early 1970s [2]. Clinicians caring for patients requiring PN in the hospital or at home must be familiar with the basic types of venous access devices, indications for their use and the prevention, diagnosis and management of associated complications.

2. venous access devices for parenteral nutrition

Most PN solutions are hypertonic [1,500-2,000 milliosmoles (mOsm) per liter] because of their high concentration of dextrose. They must be given through a venous access device whose tip lies in a large bore central vein to rapidly dilute the irritant effects of the hypertonic dextrose on the vein wall. This type of PN is called central parenteral nutrition (CPN) and in the hospital setting is given through a jugular or subclavian central venous catheter or through a peripherally inserted central catheter (PICC). For prolonged PN in the home or outpatient setting tunneled cuffed silicone catheters or chest ports are used [3-5]. The optimum catheter tip position to minimize the incidence of central vein thrombophlebitis and catheter malfunction is at the junction of the superior vena cava and right atrium [6, 7]. Appropriate catheter tip position should be confirmed by a post-catheter-insertion chest X-ray prior to the infusion of CPN solutions.

PN solutions that provide a large percentage of their kilocalories (kCal) as isotonic fat emulsions and a smaller percent as dextrose are not as hypertonic (less than 900m0sm/l) as the CPN solutions and are usually well tolerated by infusing through peripheral vein angio-catheters. See Table 12.1 for guidelines for estimating the osmolarity of PN solutions. This type of intravenous feeding is called peripheral parenteral nutrition (PPN). PPN solutions are usually used for short periods of time in hospitalized patients with reduced kCal requirements who are able to tolerate the relatively larger volumes of these dilute solutions needed to meet their caloric and amino acid needs.

Decisions concerning which venous access device and venous access route is appropriate for a particular patient are based primarily on

Table 12.1

Estimating the Osmolarity of PN Solutions

A. Total grams of amino acids per liter_x 10 =_mOsm

B. Total grams of dextrose per liter_x 10 =_mOsm

C. Total grams of 20% fat emulsion per liter_1.3-1.5=_mOsm

D. Total mEq of chloride, potassium and sodium per liter x 1 = mOsm

Add A, B, C and D to derive the total osmolarity =_mOsm

For peripheral vein tolerance, total osmolarity per liter should be 900 mOsm or less.

(Modified from Table II Errata JPEN 2006;30:177)

the anticipated duration of PN and if concentrated CPN solutions are needed to limit infused fluid volume while meeting caloric and amino acid needs (Tables 12.2 and 12.3). It would take 2,500 ml of fluid to deliver 2,000 kCal and 100 g of amino acids in a typical PPN solution, while the same nutrients could be provided in 2,000 ml of fluid using the more concentrated hypertonic CPN solution.

Other considerations are device and insertion costs and if the device can be placed at the bedside or needs to be placed in the interventional radiology or surgical suites [8] (Table 12.4).

Multilumen central venous catheters are most commonly used for hospitalized patients (Fig. 12.1). Although there is thought to be an increased incidence of infection associated with more than one lumen, this slightly increased risk is compensated for by the convenience of being able to infuse fluids, nutrients and medication through the same device [9]. When parenteral nutrition must be given to patients at home, a

Table 12.2

Duration of Use Consideration in Choosing a Vascular Access Device

Anticipated duration of use Access device Days Weeks Month(s) Year(s)

Peripheral IV *

Non-tunneled CVC * PICC

Tunneled CVC Implanted port

PICC=peripherally inserted central catheter; CVC=central venous catheter

Table 12.3

Influence of Type of Parenteral Nutrient Fluid or Choice of Vascular Access

Device

Establishing intravenous access

Access device insertion site Fluid restriction Duration

Increased nutrient needs

Small hand or arm veins No

Subclavian, PICC or jugular Yes

PPN=peripheral parenteral nutrition; CPN=central parenteral nutrition

Table 12.4

Costs and Placement considerations for Venous Access Devices

Table 12.4

Costs and Placement considerations for Venous Access Devices

Type of device

Device cost ($)

Insertion cost ($)

Bedside placement

Peripheral

1-6

24-44

Yes

angiocatheters

PICC

50-l0

300-l00

Yes

CVC

90

580

Yes

Tunneled catheter

50-225

2,800-3,200

No

Implanted port

350-600

1,000-3,500

No

(Modified from Ryder MA. Peripheral access options. Surg Oncol Clin N Am 1995;4:395-427.)

(Modified from Ryder MA. Peripheral access options. Surg Oncol Clin N Am 1995;4:395-427.)

more durable device that the patient or caregiver can maintain in the home setting is used. PICC catheters, subcutaneous chest ports and tunneled cuffed catheters are indicated for long-term use in the home setting (Figs. 12.2,12.3,12.4). Each of these devices is positioned so that its tip is at the junction of the superior vena cava and right atrium. PICC lines are inserted via an antecubital vein at the bedside or in the interventional radiology suite under ultrasound guidance. Chest ports and tunneled cuffed catheters are placed surgically or in the interventional radiology suite by cutdown or percutaneously. Commonly used access veins for tunneled catheters and ports include the internal or external jugular veins or the subclavian vein. See Fig. 12.1 showing various venous access devices used for PN in the acute care and post-acute care settings. PICC lines are associated with an increased incidence of phlebitis and catheter

Fig. 12.1. Multilumen central venous catheters are most commonly used for hospitalized patients.
Fig. 12.2. PICC catheter.
Fig. 12.4. Tunneled cuffed catheter.

dysfunction [10], and their use is usually limited to weeks or months. The decision regarding chest ports versus external cuffed catheters is mostly dependent on patient preferences. Ports require at least weekly cannu-lation, but do allow the patient periods of unencumbered activity, such as swimming or other social activities, when their ports are not cannulated. The advantages and disadvantages of ports versus tunneled catheters and the proposed location of the device are discussed with the patient prior to their placement in the home parenteral nutrition (HPN) patient. The catheter exit site or port site is marked on the patient's chest, and the surgeon or interventional radiologist is informed as to the number of lumens required.

3. venous access in patients with a major vein thrombosis

Patients who have had central venous cannulation or previous thoracic surgery in the past may have developed occlusions of major upper torso venous branches. When both of the subclavian veins or the superior vena cava are occluded, vascular access for HPN is established by accessing the inferior vena cava. Tunneled cuffed catheters can be placed by cutdown or percutaneously via the saphenous or femoral vein in the operating room or interventional radiology suite. The catheter tip is advanced through the iliac veins and inferior vena cava and positioned at the junction of the inferior vena cava and right atrium. Patients who have had iliac vein thromboses will need direct access to the inferior vena cava established via the translumbar or transhepatic approach by an interventional radiologist [11].

4. complications

4.1. Insertion Complications

Potentially life-threatening complications of catheter insertion include pneumothorax, and arterial or venous damage with resultant significant blood loss or cardiac tamponade [12]. Insertion-associated complications are more likely to occur when multiple attempts at percutaneous cannulation are made, especially if the patient is cachectic or thin [13]. After successful or attempted central vein cannulation, a chest X-ray should be obtained not only to confirm catheter tip position, but also to rule out the occurrence of a pneumothorax.

4.2. Infections

Catheter infections in vascular access devices used in the hospital or outpatient setting can occur at the exit site or systemically. Measures to prevent contamination of the external and internal lumen of the vascular access device have been recently summarized and include skin antisepsis, site dressing, hand hygiene, access-site disinfection and possibly the use of prophylactic flush solutions [14]. These measures along with previously published guidelines can help to reduce the incidence of catheter infections [15]. Every hospital, long-term care facility or home care provider should establish protocols for the care of vascular access devices to minimize the incidence of device-related infection. A comprehensive review of catheter-related infections has been recently published to guide the diagnosis and treatment of these serious complications [16].

4.3. Catheter Occlusion

When fluid flow through the vascular access device suddenly stops, it is usually due to a mechanical complication such as clamped or kinked intravenous tubing or an acutely angulated catheter. A percutaneous subclavian catheter can be occluded at the junction of the clavicle and first rib and the occlusion temporarily relieved by having the patient shrug their shoulders. If these symptoms occur a chest X-ray will establish the diagnosis of catheter pinch-off [17], and the catheter must be replaced. A more gradual occlusion to flow and or difficulty in withdrawing blood may be due to a thrombus in the lumen or near the tip of the catheter. Patency and function are usually re-established by the instillation of a tissue plasminogen activator [18].

4.4. Catheter-Associated Venous Thromboses

A recent review noted that fatal pulmonary emboli can occur associated with acute central venous thromboses in patients with central lines and must be treated aggressively with anticoagulation [6]. Diagnosis is established by a history of ipsilateral edema, discoloration, prominent chest wall venous distention, pain and tenderness over the involved vein. The diagnosis is confirmed by ultrasonography and/or venog-raphy. Preventative measures are controversial and may include oral low-dose coumadin, adding heparin to the PN solution and appropriate catheter tip positioning. Therapeutic anticoagulation should be considered for patients with a prior history of major venous thrombosis in whom prolonged central venous access is anticipated.

5. conclusion

Obtaining safe vascular access for patients receiving PN in the hospital or home setting requires the skills and judgment of knowledgeable nurses and physicians. Choosing an appropriate access device for the patient in need of parenteral nutrition and its placement by experienced clinicians using established protocols is critical for the safe administration of PN.

references

1. Dudrick SJ, Wilmore DW, Vars HM, Rhoads JE. Long-term total parenteral nutrition with growth, development, and positive nitrogen balance. Surgery 1968;64:134-142.

2. Dudrick SJ. History of vascular access. J Parenter Enteral Nutr. 2006;30: S47-S56.

3. Broviac JW, Cole JJ, Scribner BH. A silicone rubber atrial catheter for prolonged parenteral alimentation. Surg Gynecol Obstet. 1973;136:602-606.

4. Hickman RO, Buckner CD, Clift RA, Sanders JE, Stewart P, Thomas ED. A modified right atrial catheter for access to the venous system in marrow transplant recipients. Surg Gynecol Obstet. 1979;148:871-875.

5. Niederhuber JE, Ensminger W, Gyves JW, Liepman M, Doan K, Cozzi E. Totally implanted venous and arterial access systems to replace external catheters in cancer treatment. Surgery 1982;92:706-712.

6. Steiger E. Dysfunction and thrombotic complications of vascular access devices J Parenter Enteral Nutr. 2006;30:S70-S72.

7. Petersen J, Delaney J, Brakstad M, et al. Silicone venous access devices positioned with their tips high in the superior vena cava are more likely to malfunction. Am J Surg. 1999;178:38-41.

8. Ryder MA. Peripheral access options. Surg Oncol Clin N Am. 1995;4:395-427.

9. Dezfulian C, Lavelle J, Nallamothu BK, Kaufman SR, Saint S. Rates of infection for single-lumen versus multilumen central venous catheters: a meta-analysis. Crit Care Med. 2003;31(9):2385-2390.

10. Moureau N, Poole S, Murdock MA, Gray SM, Semba CP. Central venous catheters in home infusion care: outcomes analysis in 50,470 patients. J Vasc Interv Radiol. 2002;13:1009-1016.

11. Sands MJ. Vascular access in the adult home infusion patient. J Parenter Enteral Nutr. 2006;30:S57-S64.

12. Mansfield PF, Hohn DC, Fomage BD, Gregurich MA, Ota DM. Complications and failures of subclavian-vein catheterization. N Engl J Med. 1994;331: 1735-1738.

13. Collier PE, Ryan JJ, Diamond DL. Cardiac tamponade from central venous catheters. Report of a case and review of the English literature. Angiology 1984;35:595-600.

14. Ryder M. Evidence-based practice in the management of vascular access devices for home parenteral nutrition therapy. 2006;30(Suppl):S82-S93.

15. CDC MMWR. Recommendations and reports. August 9, 2002. Guidelines for the prevention of intravascular catheter related infections.

16. Raad H, Hanna HA. Intravascular catheter-related infections: new horizons and recent advances. Arch Int Med. 2002;162(8):871-878.

17. Grant J. Recognition, prevention, and treatment of home total parenteral nutrition central venous access complications. J Parenter Enteral Nutr. 2002; 26:S21-S28.

18. Timoney JP, Malkin MG, Leone DM et al. Safe and cost effective use of alteplase for the clearance of occluded central venous access devices. J Clin Oncol. 2002;20(7):1918-1922.

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