Sue Benton, RN, SCM.
Sister, RadiologyNurses have been successfully inserting tunnelled central venous catheters (TCVCs) since 1991 and have accepted this expansion of their role in order to improve the quality of the service to patients (Hamilton, 1995).
Nurses have been successfully inserting tunnelled central venous catheters (TCVCs) since 1991 and have accepted this expansion of their role in order to improve the quality of the service to patients (Hamilton, 1995).
Training nursing staff to insert TCVCs has reaped benefits for patients, with reductions in the waiting times for catheter placement and treatment, reduction in line-related infection rates in the first 30 days after placement, and an improvement in the number of lines successfully placed. (Fitzsimmons, 1997).
Using the technique of real-time ultrasonography to guide vessel puncture has several advantages (Downie, 1996; Caridi, 1998). For example, it significantly increases the probability of being able to place the catheter successfully and it reduces the risk of complications by avoiding arterial and pleural puncture (Randolph et al, 1996). In addition, ultrasonography can detect thrombotic occlusion or distorted anatomy, thereby reducing the likelihood of multiple attempts at catheter placement being required (Haire, 1994).
This paper describes the process by which two nurses - a radiology sister and nurse consultant - in the Royal Liverpool and Broadgreen University Hospitals (RLBUH) Trust were trained to place TCVCs using the imaging techniques of real-time sonography and fluoroscopy and examines the implications for practice.
Doctors have historically inserted TCVCs, usually in the operating theatre under general anaesthetic (Hamilton, 1995). This was true for patients at the authors' hospital who required TCVCs for treating haematological disorders. During 1998, 13 doctors placed 96 Hickman lines (range 1-28), of which seven (6%) involved procedure-related complications. All lines at this time were placed via the subclavian route. The appointment of a new consultant interventional radiologist in November 1997 and the difficulties in securing theatre time brought this service to the door of the interventional radiology department.
The techniques used by many interventional radiologists are real-time ultrasonography to guide the vessel puncture and fluoroscopy to aid wire manipulation and catheter placement. The right internal jugular vein (RIJV) is the preferred route because it is the shortest and straightest, which helps avoid problems of malposition (Weinstein, 1997). RIJV placement has a lower incidence of complications and higher rate of success (Senff, 1987).
In the interventional radiology department at RLBUH, the standard wire used is an 80cm J guide-wire, which is carefully manipulated into the inferior vena cava (IVC) using fluoroscopy to provide an image of the procedure.
The demand for this service grew rapidly as a result of a zero immediate-complication rate and because the central line can be used without delay because a post-procedure chest X-ray is taken to ensure correct placement and a report is provided.
However, having only one experienced operator (the consultant) able to deliver the service placed limitations on it and contributed to delays in patients' treatment. As a result, it was decided that two nurses - a nurse consultant in haematology and a radiology sister - would be trained to safely place TCVCs using imaging techniques and the RIJV as the preferred route. The choice of the two individuals was based on their experience and competencies. The radiology sister had observed and assisted with many catheter insertions, with and without the use of ultrasound, and the nurse consultant had expert knowledge of haematological conditions and of caring for patients with TCVCs. Both nurses are permanent staff members and are satisfied that the expansion of their roles is in accordance with the UKCC guidelines, The Scope of Professional Practice.
The protocols for this nursing intervention were written and received trust board approval. To ensure the nursing staff practised only once competent to do so, the protocols included a comprehensive training programme consisting of two parts, theory and practical experience. Other factors included in the protocol were the rationale for expanding the nurses' roles, benefits for the patients and service, contraindications to nurses inserting TCVCs and audit parameters. The protocols aimed to safeguard against the potential complications associated with TCVCs that usually occur due to operator inexperience (Mansfield et al, 1994).
The training consisted of two distinct parts, theory and practical experience. The theory involved improving the nurses' knowledge of the anatomy of the neck and the chest, the basic physics of ultrasound, pharmacology of the drugs to be used and recognition of the complications of central venous catheterisation and their management, which was achieved by personal study and teaching by the two consultant radiologists. Teaching was in the form of short tutorials before and after line placement.
Ultrasound (Box 1) was probably the most difficult concept to understand - nurses usually accompany patients for invasive procedures under ultrasound guidance, but very few nurses use ultrasound on a routine basis.
Practical experience was gained by observation, the use of an in vitro model (prototype), assisting with the procedure and supervised practice, which took place in the interventional radiology suite of the authors' hospital.
During the initial stages of the supervised practical session it became apparent that the use of ultrasound to guide blood-vessel puncture is very safe in the hands of a trained person, but the opposite is true in the hands of a novice. It was therefore deemed essential that in vitro practice should take place to reduce the risk of erroneously puncturing the carotid artery due to poor sonographic visualisation of the needle tip.
The technique of using tissue phantoms (turkey breast) to aid ultrasound guided vascular puncture has been described (Davies, 2001) but no in-vitro model existed. The clinical engineering department of Liverpool University was approached about making such a model. Money was obtained through a charitable funds grant and the prototype was made.
The lead consultant radiologist initially supervised the nursing staff during all the early catheter placements. A second consultant radiologist with experience in inserting TCVCs added to the nurses' training by providing additional support and explaining the use of an alternative approach that uses a micropuncture set consisting of a 19g needle and 0.18mm guidewire for the initial puncture.
The procedure, risks and possible complications are discussed with the patient after which the nursing staff, with the patient's permission, insert the line under supervision. Immediately before line insertion, the patient's neck is scanned using ultrasound, which is particularly valuable in patients who have had previous central venous lines. The scan confirms patency and size of the jugular vein and the relationship of the jugular vein to the carotid artery.
Patients are monitored throughout the procedure in accordance with recommendations from the National Confidential Enquiry into Perioperative Deaths (CEPOD, 2000).
The Department of Health (2001) suggests that it is the magnitude of barrier protection used during catheter placement, rather than the surrounding environment, that makes a difference to the risk of infection.
All catheters are inserted in a dedicated interventional room using optimum aseptic technique (DoH, 2001) and a double-skin preparation of povidone-iodine solution and alcoholic chlorhexidine to reduce the risk of introducing infection at the insertion stage.
The technique described above is used for puncturing the RIJV. An 80cm J guidewire is then gently passed through the needle; ultrasound is used to confirm that the wire is within the lumen of the jugular vein.
The guidewire is next guided into the IVC with the aid of fluoroscopy, for which the skills of senior radiographers are required.
A short subcutaneous tunnel is created along the chest wall; the catheter is inserted through the tunnel. The catheter length may be gauged using fluoroscopy, ensuing that the tip of the catheter lies in the lower third of the superior vena cava (SVC). The catheter is cut to size.
A series of dilators are used to dilate the jugular vein in order to accommodate the peel-a-way sheath that is needed to place the catheter. If resistance is felt at any stage then fluoroscopy is used to visualise the dilator and the guide wire.
The catheter is prepared by flushing it with saline 0.9% and ensuring it is clipped and capped to prevent air embolism. Catheters are always longer than are needed and are cut to the appropriate size. The length required is estimated by placing the catheter on the patients chest (sterile conditions apply) fluoroscopy may be used to aid the estimation ensuing that the tip will lie in the lower third of the SVC after placement.
The guide wire is placed in the IVC to prevent buckling of the wire as the dilators are passed over it. The catheter will lie in the SVC. We have seen short guide wires (placed in the SVC) buckle, sending the dilators in the direction of the vein wall with the potential to cause harm. Our practice is to pass the guidewire into the IVC to prevent this happening.
The pressures involved within the central venous circulation are directly related to pressures involved with respiration. During expiration, central venous pressure is higher than atmospheric pressure. On inspiration, air can be sucked through the open end of a needle or the peel-away sheath needed to place the catheter. Both the Trendelenberg position and Valsalva manoeuvre ensure that central venous pressure remains higher than atmospheric pressure (Drewitt, 2000).
Either the Trendelenberg position or the Valsalva manoeuvre is used to insert the catheter through the peel-away sheath, preventing air embolism. With the catheter in place, the sheath is removed and fluoroscopy is used to ensure the line is not kinked. Kinking may occur at the insertion site and can be remedied by gentle downward traction on the catheter. The catheter is aspirated to ensure adequate flow and is then flushed with Hepsal. The catheter is secured in place with a retaining suture and clear dressing (DoH, 2001).
Post-insertion chest X-ray
Post-procedural radiographs are performed to exclude complications such as pneumothorax and to determine catheter position. A study by Chang has suggested that post-procedural chest X-rays should not be routinely performed for internal jugular catheters placed using image guidance (Chang et al, 1998).
In the authors' hospital we continue to provide a post-procedural chest X-ray.
Other studies have shown that movement occurs when the patient's posture changes from the intraprocedural supine position to the upright position (Kowalski et al, 1997; Nazarian et al, 1997). Trerotola suggests that 2-5% of catheters require some adjustment to maintain catheter function and avoid possible long-term complications, such as venous thrombosis (Trerotola, 1998).
Implications for practice
To date the nursing staff have placed 45 Hickman lines under supervision; the numbers are not big but the emphasis has been placed on patient safety.
The use of using sonography to guide vessel punctures in the placement of central venous access devices is a well-recognised technique and is safe in the hands of trained personnel; improving the success rate of insertion and reducing the complication rate.
The development of the in vitro model will allow nurses and junior doctors the opportunity to practise the technique and obtain the skills necessary to use it safely. Plans to establish training courses in the authors' hospital should help promote the technique in the interest of patient safety.
The concept of nurses placing TCVCs is not new but training nursing staff and other members of the health-care team to use this technique will enhance the quality of patient care.
The authors would like to thank R.G. McWilliams, Consultant Radiologist; C. Boyd, Consultant Radiologist; H.K. Hewitt, Superintendent III Radiographer; the Interventional Radiology Team and Haematology nursing staff, Royal Liverpool and Broadgreen University Trust.
Caridi, J.G., Hawkins, I.F., Wiechmann, B.N. et al. (1998) Sonographic guidance when using the right internal jugular vein for central venous access. American Journal of Roentgenology 171: 5, 1259-1263.
National Confidential Enquiry into Perioperative Deaths. (2000)Interventional Vascular Radiology and Interventional Neurovascular Radiology: A Report of the National Confidential Enquiry into Perioperative Deaths. London: NCEPOD. Available at www.ncepod.org.uk
Department of Health. (2001)The Guidelines for Preventing Infections Associated with the Insertion and Maintenance of Central Venous Catheters. London: The Stationery Office.
Downie, A.C., Reidy, J.F., Adam, A.N. (1996)Short communication: tunnelled central venous catheter insertion via the internal jugular using a dedicated portable ultrasound device. British Journal of Radiology 69: 818, 178-81.
Davies, R.P., Kew, J. (2001)Tissue phantom for learning US-guided vascular punctures (letter). Journal of Vascular Interventional Radiology 12: 2, 267-268.
Dougherty, L. (2000)Central venous access devices. Nursing Standard 14: 43, 45-50.
Drewitt, S.R. (2000)Complications of central venous catheters: nursing care. British Journal of Nursing 9: 8, 468-478.
Fitzsimmons, C.L. (1997)Central venous catheter placement: extending the role of the nurse. Journal of the Royal College of Physicians of London 31: 5, 533-535.
Haire, W.D. Lieberman, R.P. (1994)The New England Journal of Medicine 331: 26, 1769-1770.
Hamilton, H. (1995)Central lines inserted by clinical nurse specialist. Nursing Times 91: 17, 38-39.
Kowalski, C.M., Kaufman, J.A., Rivitz, S.M. et al. (1997)Migration of central venous catheters: implications for initial catheter tip positioning. Journal of Vascular and Interventional Radiology 8: 5, 443-447.
Mansfield, P.F., Hohn, D.C., Fomage, B.D. et al. (1994)Complications and failures of subclavian catheterisation. New England Journal of Medicine 331: 26, 1735-1738.
Nazarian, G.K., Bjarnason, H., Dietz, C.A. Jr. et al. (1997)Changes in tunnelled catheter tip position when a patient is upright. Journal of Vascular and Interventional Radiology 8: 5, 437-441.
Randolph, A.G., Cook, D.J., Gonzales, C.A., Pribble, C.G. (1996)Ultrasound guidance for placement of central venous catheters: a meta-analysis of the literature. Critical Care Medicine 24: 12, 2053-2058.
Rosen, M., Lotto, P., Ng, S. (1992)Handbook of Percutaneous Central Venous Catheterisation (2nd edn). London: W.B. Saunders.
Senff, M.G. (1987)Central venous catheterisation: a comprehensive review, part 1. Journal of Intensive Care Medicine 2: 163-175.
Trerotola, S.O., Johnson, M.S., Moresco, K.P. (1998)Re: chest radiograph after placement of internal jugular central venous access devices (letter). American Journal of Roentgenology 171: 4, 1158-1159.
UKCC. (1992)The Scope of Professional Practice. London: UKCC.
Weinstein, S.M. (1997)Plumer's Principles and Practice of Intravenous Therapy (6th edn). Philadelphia, Pa: J.B. Lippincott.