V. Hinton and M Fish, Nottingham City Hospital, UK

Address for Correspondence
Vicky Hinton
Renal Outpatients
NCHT
Hucknall Road
Nottingham
NG5 1PB
UK
vhinton@ncht.trent.nhs.uk
mfish@ncht.trent.nhs.uk

Biodata
Vicky Hinton has worked on the renal unit at Nottingham City Hospital for the past four years and has been seconded two days a week to assist in implementing a palliative care programme on the renal unit

Maria Fish is a Renal Clinical Nurse Specialist. She has worked in the renal unit at Nottingham City Hospital for the last nineteen years. For the past four years she has specialised in predialysis and palliative care, extending her role to develop a renal palliative care team.

Key words
End of life; Care pathways; Renal; Palliative and supportive care

Summary
Background - A care pathway for the end-of-life had been implemented onto the two renal wards. An audit was performed to highlight potential issues and areas for development.

Method - The audit consisted of a base review of documentation from the medical notes of 10 patients who had died an ‘expected’ death prior to commencing the renal Integrated Care Pathway (ICP) for the end of life and then 10 patients who had died whilst using the ICP documentation. A questionnaire was also given out to nursing staff who had used the ICP documentation. The results were collated and analysed.

Results - In the base review 100% of the documentation looked at did not provide a regular documented assessment of symptoms that are common in the terminal phase of life. The ICP provided a documented assessment of all of these main symptoms. The base review indicated a good response by doctors to meet the potential needs of the patient, but the ICP improved on this. This was through the use of the pre-emptive prescription. 80% of all patients were pain free, not agitated, had no nausea or vomiting or respiratory secretions. The 2 patients that had pain received further analgesia and were then pain free at the next assessment. One of the most positive aspects of the audit was that 90% of relatives were aware that the patient was dying and 100% had the plan of care discussed with them.

Conclusion - Implementing the ICP has generated the opportunity to deliver a hospice model of care to a busy renal unit. It has allowed best practice, and a measurable standard of care, in the final stages of patients’ lives. Staff find the documentation easy to use and also see it as enhancing patient care.

A. Brousseau, Centre Hospitalier Ambulatoire Régionale de Laval, Québec , Canada

Address for correspondence
Anna Brousseau
8446 Place Aldéric-Beaulac
Montréal,
Québec , H2M 2S8
Canada
Tel: home: 514-389-3024
Tel work: 450-978-8300 p 8452
abrousse_charl@ssss.gouv.qc.ca

Biodata
Anna Brousseau graduated as a nurse in 1986. She has worked in nephrology since 1990. She worked in Sacré-Cœur Hospital as head-nurse assistant in the dialysis department. Since 2001 she has worked in the pre dialysis clinic helping to prevent deterioration of renal insufficiency at (CHARL) Centre Hospitalier Ambulatoire Régionale de Laval.

Key words
Pre dialysis clinic; Hypertension; Prevention; Team work

Summary
Prevention in nephrology is only possible with the cooperation of patients and their families. The nurse plays a main role in working with patients and is a major player in the team, responsible for follow-up of the patient, where the earliest interventions can help delay and sometimes avoid dialysis. The hypertension clinic is the beginning a continuum until dialysis. This paper describes three clinics that are managed in the renal service and indicates how they contribute to offering optimal care to a renal population.

Dear Readers, this issue of the EDTNA/ERCA Journal is the last that I will edit as English Co-editor. I have worked as a volunteer in this post for the past six years and the experience has been both tremendously rewarding and humbling. I have had the opportunity of helping sustain our present journal over the years, which has gone from strength to strength and today is a respected peer-reviewed journal promoting excellence in renal care.

The journal has always aimed to keep professionals informed of new developments by providing a forum for the publication of original and scholarly articles. These have addressed all aspects of renal practice, education, management and research. The journal encourages exploration of the relationship between theory and practice and the cross-fertilization of ideas between the multiprofessional team involved in renal care not just in Europe but worldwide with recent papers published from Australia and Israel.

It has been my pleasure to work for the journal as a volunteer where I have been supported by other wonderful volunteer co-editors from France, Germany, Italy, Spain, Holland and Greece. Bertrand, Kai, Ilaria, Maria, Freddy and Natasa have been a pleasure to work with; always so professional, conscientious, diligent and dedicated to the organisation and journal alike. I will also very fondly remember Helen and Simona who were volunteers for some time and similarly committed. Our annual meetings were so valuable and involved discussing how we could make improvements to the journal with some social time built in where we could get to know each other a little more and build on our friendships, which have always been so important within the EDTNA/ERCA. Sharing of experiences has meant that new ideas have been generated and cohesiveness within the team ensured.

Our team was always so well supported by Anna Marti, our very illustrious editor who has worked tirelessly to promote the journal and ensure that it remains professional and suited to the needs of you our readers. I thank her also for her unyielding encouragement and friendship. She truly is a wise mentor and I will not forget how she has helped me develop my editorial skills with honesty and humour.

Your new English Co-editor is Ray James who works in the same hospital as me, Barts and The London NHS Trust in London. Ray, I know, is looking forward to the challenge of maintaining the high standard of the journal and is an experienced renal professional who is committed and conscientious. I wish him luck in his new volunteer post.

Paola Sclauzero RN, Sabina Casarotto RN, Maurizio Martingano RN, Fulvio Morpurgo RN, Ilaria Rocconi RN, Katiuscia Scala RN, Mariafiore Vescovi RN, Giovanni Galli MD
S.C. Nefrologia e Dialisi (Head: G. Panzetta, MD) – Trieste, Italy

Address for Correspondence
Paola Sclauzero
S.C. Nefrologia e Dialisi
A.O.U. “OO.RR.”
Ospedale di Cattinara - Strada di Fiume, 447
Trieste ,
Italy
Tel. +39 040 399 4268 - 4255
Fax: +39 040 399 4250
giovanni.galli@aots.sanita.fvg.it
dialisi-peritoneale@aots.sanita.fvg.it

Biodata
Paola Sclauzero was born in Trieste in 1974 and obtained her nursing degree in 1996. She attended several formative courses concerning dialysis and training skills. She has worked in the Nephrology and Dialysis Department of Trieste since 1997 in the Haemodialysis Unit and in the Peritoneal Dialysis Unit. She takes part in the training of staff and of university students.

Key words
Acute renal failure; Dialysis; Nurse; Intensive Care; Patient care planning

Summary
Collaboration between the Intensive Care Unit (ICU) and nephrology nurses is needed to ensure adequate care of critically ill patients with acute renal failure (ARF). To improve this collaboration a questionnaire was circulated to the 122 ICU nurses in the hospital to appraise their knowledge on ARF. A Refresher Course to update on ARF was then organised. Colleagues' interest in the initiative was elevated: 66% of questionnaires were completed which included 88% of nurses attending the course. The experience showed, through measurable results, that team work is essential to collaborative nursing plans. The initiative allowed improvement in the quality of nurses’ communication and was accompanied with a significant reduction in short-term mortality rate of dialyzed ARF patients (45 versus 50%; p=0.045, chi-square test). Despite the limitations of this short period of observation (one year) the results are judged as useful. Collaboration ensures support for colleagues on a daily basis and during critical moments and can encourage appreciation of the nursing profession.

Per-Ola Wictor and Roger Svensson, Gambro Lundia AB, Lund, Sweden

Keywords
Central venous catheter; Central dialysis catheter; Electrical safety; Potential equalisation; Patient leakage current

Addresss for correspondence
Per-Ola Wictor / Roger Svensson
Gambro Lundia AB
Box 10101
2201 10 Lund
Sweden
per-ola.wictor@gambro.com
roger.d.svensson@gambro.com

Biodata
Per-Ola Wictor has a Masters of Science in Electrotechnical engineering. He has worked for over 10 years with Gambro Renal Products developing dialysis machines.
Roger Svensson has a Masters of Science in Electrotechnical engineering. He has more than 10 years of experience in biomedical engineering.

Summary
In some cases in haemodialysis blood access is established with a special type of central venous catheter (CVC), sometimes called a central dialysis catheter (CDC), instead of an AV fistula or graft. This central venous catheter tip is placed very close to the heart, increasing the probability of a leakage of electrical current passing through the heart. This may cause arrhythmia or ventricular fibrillation. This current is generally referred to as patient leakage current and has to be kept very low for patient safety. All staff involved in CVC treatments, nursing staff as well as technicians, should be aware of this particular risk to the patient.

The purpose of this article is to discuss the background of the above-mentioned safety issue and suggest precautionary measures of minimising this risk. Precautions discussed include potential equalisation, use of separating transformers, periodic maintenance (normally performed by a service technician) and physical placement of the equipment used in the vicinity of the patient (normally the responsibility of the nursing staff).

Maria Lúcia Araújo Sadala 1, Marisa Lorençon 2

1.Phd, RN
Professor of Nursing Relationships, Researcher
Nursing Department, Faculty of Medicine, Botucatu,
Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP)
Botucatu, São Paulo, Brazil

2. RN, Department of Haemodialysis
Hospital da Clínicas de Botucatu
Faculty of Medicine
Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP)
Botucatu, São Paulo, Brazil

Address for correspondences
Maria Lúcia Araújo Sadala
Avenida Mário Arita, 163
Araraquara, São Paulo,
CEP 14802-404
Brazil
Tel (55) 16-2365003
sadal@uol.com.br

Biodatas
Maria Lúcia A. Sadala is an Associate Professor of The Department of Nursing in The School of Medicine of Botucatu, São Paulo, Brazil. Since 1999 she has participated in educational programmes of nursing research in the renal unit of the university hospital and has contributed to various research in this unit.

Marisa Lorençon has been a dialysis nurse since 1998. She is interested in research, which investigates the experiences of haemodialysis patients and their families.

Keywords
Haemodialysis, Patient experience, Merleau Ponty Existential phenomenology approach, Dialysis nursing

Summary
The aim of present study is to describe the experience of patients undergoing haemodialysis starting from their own perception. A qualitative perspective using Merleau Ponty’s Existential Phenomenology was considered to be the most appropriate methodology for this study. 15 patients were interviewed in a haemodialysis unit at a Brazilian teaching hospital. Interviews were based on the question “What does the experience of living with a haemodialysis machine mean?” Convergences in speeches were grouped into three categories: the machine, improvement in quality of life, reflection on patients’ experience. These findings show the existential reality patients experience. A haemodialysis machine dictates their lives: they have to accept strict rules controlled by a team of healthcare providers. They realize it has to be so and there is no way out. It is the only way to get some relief from the disease’s symptoms. The feeling is mostly acceptance of the condition. Healthcare providers’ dedication is recognized. Some participants complain about painful procedures, others deny them, others fantasize the reality. An essential piece of information is the lack of future perspectives; few patients mentioned the possibility of a transplant or the possibility of carrying out their own care. The study may contribute in outlining new perspectives for nurses to understand the needs of patients undergoing haemodialysis. An approach accepting patients’ views will probably bring awareness to patients as to the possibilities of helping with their own treatment.

TABLE 1. PARTICIPANTS OF THE STUDY

F. Lopot, F. Švára, V. Polakovic, Department of Medicine, Prague – Strahov, Czech Republic

Address for correspondence
Frantisek Lopot, PhD.
General University Hospital
Department of Medicine
Sermirska 5, 169 00 Prague 6 – Strahov
Czech Republic
f.lopot@vfn.cz

Key words
Vascular access, haemodialysis, access flow, monitoring, surveillance methods, vascular access guidelines

Summary
This article reviews vascular access (VA) assessment methods and procedures. It gives an overview of the existing methods for bed-side VA assessment by means of pressures, recirculation and access flow measurement. Pros and cons of the methods are discussed and additional benefits of a combined recirculation and access flow measurement are explained. Present vascular access care guidelines are discussed, namely the K/DOQI and EVAS documents. Practical setup of a vascular access monitoring and surveillance system is illustrated with data from authors’ own unit where such a system has been in use since 1999. The issue of adequate target setting is analysed in view of published works on clinical impact of access surveillance system introduction (timely detection of access stenosis and access patency). Critical re-evaluation is needed especially in current QVA threshold and intervention timing.

A. Pagels, S. Heiwe, B. Hylander, Karolinska University Hospital, Stockholm, Sweden

Address for correspondence
Agneta Pagels,
Karolinska University Hospital ,
Stockholm ,
Sweden
agneta.aspegren-pagels@karolinska.se
Tel; +46 851779835

Biodata
Agneta Pagels (RN, MS), Susanne Heiwe (RPT, PhD) and Britta Hylander (MD, PhD) work together in a multidisciplinary pre-dialysis team at the out patient clinic within the Department of Nephrology, Karolinska University Hospital in Stockholm.

Key words
Nutrition assessment; Kidney failure; Chronic; Hand strength; Nursing

Summary
Introduction and aim: Protein-energy malnutrition (PEM) is a well-known problem in the care of persons with chronic kidney disease (CKD). Continuous assessment of nutritional status (NS) is therefore recommended in dialysis care as well as in the care of pre dialysis patients. Subjective Global Assessment (SGA) is a multifactor, subjective method for assessment of a patients’ NS. Reduced handgrip strength (HGS) is associated with PEM and considered to be a reliable nutritional parameter that reflects loss of muscle mass. The aim of this retrospective study was to analyse NS in pre dialysis patients with focus on the significance of HGS.

Patients and study design: In this retrospective study HGS and NS assessed by SGA in 112 pre dialytic individuals were analysed. The patients’ mean Glomerular Filtration Rate (GFR ) was 14(±4) ml/min. and their mean age was 63 (±15) years. The patients were assessed consecutively from November 2001 to November 2003. Sixty-three percent of these patients were assigned a protein-restricted diet (PRD) 0,6-0,8g/kg/day.

Results and conclusions: Relatively few patients (13%) were classified as malnourished according to SGA but many reported experience of fatigue, loss of appetite and reduced level of physical activity. Few patients (6%) were underweight (BMI <20), whereas 58% were overweight (BMI>25). Patients on a PRD did not have impaired NS, compared to patients not on a PRD. Patients who had some degree of malnutrition tended to have reduced HGS. Among male patients, those with a lower level of physical activity tended to have lower HGS. Among the female patients, those who experienced loss of appetite and/or feeling of fatigue tended to have lower HGS. The pre dialysis patients had lower HGS compared to predicted norm for healthy subjects.

Susan Ann Heatley, Pre-Dialysis Nurse Specialist, Central Manchester and Manchester Children’s University Hospital, Manchester, UK

Address for correspondence
Susan Ann Heatley RGN, BSc (Hons)
Pre-Dialysis Nurse Specialist
Central Manchester and Manchester Children’s University Hospital
Renal Directorate
Oxford Road
Manchester
M13 9WL
England

Key words
Patient education; Pre-dialysis; Patient led forums

Summary
In order for patients to make an informed choice about renal replacement therapies, it is important that they are given sufficient and appropriate information, which must include explanations about their condition and likely outcomes with or without treatment. Furthermore information regarding the reality of living with dialysis, its strict regimes and patient’s commitment to self care are imperative to enable patients to adapt to a life changing, on-going, often relentless treatment. Encouraging patients to take control of their chronic illness through the provision of education support and choice is fundamental to the successful outcomes of the patient’s journey through the pre-dialysis phase of their illness. This paper describes the implementation of Patient-led Forums designed to offer an education programme for pre-dialysis patients and the benefits gained by those who have attended.

K Pugh-Clarke 1, PF Naish 1, TM Mercer 2

1 Department of Nephrology, University Hospital of North Staffordshire, Stoke-on-Trent , England, UK
2 School of Health Sciences, Queen Margaret University College, Edinburgh , Scotland, UK.

Address for correspondence
Karen Pugh-Clarke
Ward 26
Royal Infirmary
Princes Road
Hartshill
Stoke-on-Trent
Staffordshire
ST4 7LN
England
UK
Tel. +44 1782 554186
Fax. +44 1782 554615
Karen.Pugh- Clarke@uhns.nhs.uk

Biodata
Karen Pugh-Clarke MSc BSc (Hons) RN has worked as a renal nurse for 10 years. Having worked initially in general nephrology and haemodialysis, she now holds the joint position of Anaemia Management Sister (Chronic Kidney Disease) and Renal Research Nurse. The presented study was undertaken as part of her MSc (by research), which examined quality of life and physical function in chronic kidney disease. Karen is currently studying for a PhD at Manchester Metropolitan University.

Key words
Quality of life; Chronic kidney disease; Uraemic symptoms

Background
Quality of life (QOL) is suboptimal in end-stage renal disease. However, studies indicate that QOL is already impaired prior to the initiation of renal replacement therapy, implying that the initial decline originates in the chronic kidney disease (CKD) phase of the renal disease trajectory. Given the significance of QOL as a clinical outcome, there is a paucity of QOL research in CKD.

Aims
To measure QOL at three distinct phases (based on creatinine clearance – Ccr) of the disease trajectory in CKD: normal renal function (NRF) with underlying renal disease, moderate CKD, and advanced CKD (Ccr ³ 75, 40-60, and £ 30 ml/minute, respectively), and to establish if QOL is different between these groups.

Methods
Data was collected from 25 patients from each of the Ccr bands (N=75). We measured self-reported QOL (Schedule for the Evaluation of Individual Quality of Life – SEIQOL), uraemic symptoms (Leicester Uraemic Symptom Scale – LUSS), and laboratory variables.

Results
SEIQOL was significantly lower (p < 0.001), and symptom number, frequency, and intrusiveness significantly higher (all p < 0.001) in the advanced CKD group when compared to the NRF group. Although SEIQOL and symptom intrusiveness did not differ between the advanced and moderate CKD groups, SEIQOL was significantly lower (p < 0.05) and symptom intrusiveness significantly higher (p < 0.05) in the moderate CKD group when compared to the NRF group.

Conclusion
QOL is already impaired in moderate CKD. The significant difference in QOL and symptom intrusiveness between the moderate CKD and NRF groups may denote a causal relationship between symptom intrusiveness and QOL early in CKD.

J. King, Department of Renal Medicine, Reading, Berkshire, UK

Address for correspondence
Jennie King
Renal Department, Royal Berkshire Hospital,
London Road ,
Reading ,
Berkshire RG1 5AN
UK
Tel; +44 118 322 8332
Jennie.King@rbbh-tr.nhs.uk

Biodata
Jennie King is responsible for renal education, research and development in the renal department at the Royal Berkshire Hospital in Reading, UK. She started her renal career back in 1981 in London gaining experience in all fields of renal nursing before specializing in training and Research and Development. Jennie is the UK study co-ordinator for DOPPS, Dialysis Outcomes and Practice Patterns Survey.

Key words
Training; Valued; Recruitment and retention; Job satisfaction; Patient outcome

Summary
The aim of this study was to find out if offering specialist renal training courses enhanced staff recruitment and retention. An audit of staff with specialist renal skills acquired through training was completed. Analysis of the records available in this Trust since 2003, reporting on staff retention and increased nurse satisfaction following renal course attendance, were used in this study. The research used semi-structured interviews gaining qualitative data. The participants were all staff who had undertaken renal courses provided by this Trust. The results showed that when the interviews were thematically analysed, key themes emerged, which displayed enhanced insight, confidence and increased skill base. The quantitative data concerning staff retention, staff movement and staff sickness, helped to identify that not only do staff actually stay longer but also appear to develop advanced skills and knowledge as well as more positive attitudes. In summary, it was shown that by offering specialist training there is an increased number of skilled renal nurses presenting for employment attracted by the opportunity of undertaking specialist renal courses. They in return, benefit from the advanced renal programme, which enables them to deliver better quality of care with increased job satisfaction.

S. Johnson and P. Byrne on behalf of the Renal Anaemia Coordinators, Illawarra Health Service, Wollongong, NSW, Australia

Address for Correspondence
Suzanne Johnson
The Renal Centre
Wollongong Hospital
Crown St
Wollongong, NSW 2500
AUSTRALIA
johnsons@iahs.nsw.gov.au

Biodatas
Suzanne Johnson RN, BSc (Nursing), is a Renal Anaemia Coordinator employed by South Eastern Sydney Illawarra Health, based in the Renal Clinic at Wollongong Hospital, Wollongong, NSW, Australia. Suzanne has been nursing for 22 years with a critical, chronic and complex care background, and entered the renal arena 4 years ago. Suzanne is currently working towards a Masters in Nursing at Wollongong University.

Pauline Byrne RN is a renal nurse specialist, with over 20 years experience. Pauline’s lengthy career in nursing has included time as a haemodialysis nurse manager and nurse educator. She currently job shares the position of Renal Anaemia Coordinator with Suzanne Johnson. She is an active participant in national conferences and has presented widely.

Key Words
anaemia; chronic kidney disease; erythropoietin; database; Australia

Summary
The Renal Anaemia Management (RAM) Programme is a unique service available in 18 major renal centres around Australia. Since its inception some 6 years ago, the software package has been modified to accommodate the needs of the renal team and the renal patient population. In addition, with the support of nephrologists, the RAM software has created a specialised role, that of the Renal Anaemia Coordinator (RAC).

The RAM software collects clinical data and patient characteristics from patients with anaemia associated with renal disease. This is an integral part of a national exchange of information for the optimal management of the overall health of the renal patient population.

The RAM database is a valuable tool that has changed the practice of anaemia management and improved the outcomes of patients with renal insufficiency. RAM provides a rapid method of reviewing haematological and biological parameters on a regular basis with a multidisciplinary approach. At a glance, RACs can now detect trends in determining vascular access programming, dietetic review, and patient education and support services.

This has allowed the Renal Anaemia service to reach common goals and improve outcomes. The RAC provides a point of contact and education for patient, family members and their general practitioner’s regarding erythropoietin therapy. This advancement in technology has revolutionised the collection of information about individual patients and their presenting history of renal failure. It has also allowed for earlier recognition and treatment of renal disease.

Fredrik Uhlin, RN, B.Sc. ¹, Ivo Fridolin, Ph.D ², Martin Magnusson, M.D., Ph.D. ¹ and Lars-Göran Lindberg Ph.D ³.

¹ Department of Nephrology, University Hospital, Linköping, S-581 85 Linköping, Sweden
F. Uhlin: E-mail: Fredrik.Uhlin@lio.se, Telephone: + 46 13 221 804; Fax: + 46 13 224 514;
M. Magnusson: E-mail: martin.magnusson@lio.se, Telephone: + 46 13 222 213; Fax: + 46 13 224 514;

² Centre of Biomedical Engineering, Tallinn Technical University, EST-19086 Tallinn, Estonia
I. Fridolin: E-mail: ivo@cb.ttu.ee; Telephone: + 372 6202206; Fax: + 372 620 2201

³ Department of Biomedical Engineering, Linköping University, University Hospital, S-581 85 Linköping, Sweden
L.-G. Lindberg: E-mail: larli@imt.liu.se; Telephone: + 46 13 222 454; Fax: + 46 13 101 902

Address for Correspondence
F. Uhlin
Department of Nephrology
University Hospital , Linköping,
S-581 85 Linköping, Sweden
E-mail: Fredrik.Uhlin@lio.se,
Telephone: + 46 13 221 804;
Fax: + 46 13 224 514;

Biodata
Fredrik Uhlin worked as a nurse (RN) in the haemodialysis unit at the Dept of Nephrology, Univ. Hospital, Linköping, SWEDEN since 1989, research nurse since 1998, obtained B.Sc. degree 2001. Ph.D.-student (2005) at the Dept. of Medicine and Care, University of Linköping; investigating the possibility to develop an optical on-line monitoring system based on UV-absorbance.

Keywords
dialysis adequacy; dialysis clearance; haemodialysis monitoring; on-line adjustments; ultra violet absorption

Introduction
Day to day variations occur in treatment efficiency in haemodialysis (HD) patients (1). The NKF-DOQI guidelines recommend a monthly control of dialysis dose using pre and post dialysis blood samples (2). Frequent use of an on-line monitoring system can makes it possible to evaluate every HD treatment to provide an adequate dialysis dose consistently given (3).
On-line monitoring systems have been developed during the last two decades with different settings e.g. an ammonium ion sensor for direct measurement of urea loss offering dialysis parameters such as dialysis dose (Kt/V) urea reduction ratio (URR), Total Removed Urea (TRU), Protein Catabolic Rate (PCR) (4) and the ionic dialysance method for Kt/V measurement (5).
In research, optical on-line methods have recently been clinically tested for the monitoring of urea concentration during dialysis e.g. using the Fourier-transform infrared spectrometer (6) and our group has presented the possibility to estimate Kt/V (7), TRU and PCR (8) by ultra violet (UV) light absorbance measurement of the spent dialysate.
Urea itself is not detected by UV-absorbance measurement; instead a total absorbance is measured, reflecting overall retention of accumulated UV-absorbing solutes in the spent dialysate. There exists a good correlation (near 1.0 for each patient) between UV-absorbance and concentrations in the spent dialysate of several small removed waste solutes such as urea, creatinine and uric acid (9). The mean UV-absorbance contribution from every compound in the spent dialysate varies at different wavelength but on-line monitoring of UV-absorbance seems to be a good approximation of urea clearance in a specific range of wavelengths at 280-320 nanometres (nm) (10).
The aim of this study was to show that monitoring the spent dialysate during haemodialysis using UV-absorbance, may bring new information about the clearance process.

Summary
Background: On-line monitoring systems of the spent dialysate, used to estimate dialysis dose, have been developed with different instrumentation during the last two decades. The routine use of an on-line monitoring system has been suggested to provide to give an adequate dialysis dose to the haemodialysis (HD) patients. The aim of this study was to show that monitoring the spent dialysate using UV-absorbance may bring new information about the clearance process.
Methods: 108 HD treatments distributed among 16 clinical stable patients were monitored on-line using ultra violet (UV) absorbance. For the measurement of UV-absorbance a spectrophotometer was connected to the fluid outlet of the dialysis machine with all spent dialysate passing through a flow cuvette. The UV-absorbance curves were examined in combination with the recorded observations of events that occurred during the studied treatments.
Results: The study demonstrates that UV-absorbance visualizes different kind of events such as hypotension, conductivity alarms, restricted flow in artery needle blood pump stop that often occur during dialysis treatment.
Conclusion: An on-line UV-monitoring system with a high sampling rate makes it possibility to identify variations in dialysis clearance of different origin and gives feedback after performing interventions during a dialysis session.

Materials and Methods
Subjects
108 dialysis sessions distributed among 16 patients, 7 females and 9 males (mean age 64 years) on chronic thrice-weekly haemodialysis at the Department of Nephrology, University Hospital of Linköping, Sweden, were included in the study. The patients were clinically stable, 15 patients were dialysed via an artery-venous fistula and one patient was dialysed via a central dialysis catheter. An additional data overview of the studied patients is shown in Table 1. The dialysis machines used were Fresenius 4008H (Fresenius Medical Care, Germany) and Gambro 200 (Gambro Lundia AB, Sweden). Several dialyzers were used, both low and high flux membranes from different manufactures. The dialysate flow (Qd) was 500 mL/min and the blood flow (Qb) varied between 200-320 mL/min.
The Ethics Committee approved the study protocol and informed consent was obtained from all patients.

UV-absorbance monitoring
During the on-line measurement, a double-beam spectrophotometer (UVIKON 943, Kontron, Italy), accuracy of ± 1%, was connected to the fluid outlet (i.e. the drain tube) of the dialysis machine with all spent dialysate passing through the specially designed optical flow cuvette (9). With a sampling frequency at one per 30 second, a single wavelength measurement was performed and the wavelengths used were; 280, 285, 297, 310 nm (N = 108). Figure 1 shows a simplified illustration of the instrumentation.
The absorbance A of a solution measured in arbitrary units [a.u.], obtained by the spectrophotometer using the pure dialysate as the reference solution, was determined as: A = log(l_r / l_r+s) where I_r is the intensity of transmitted light through the reference solution (pure dialysate) and I_r+s is the summated intensity of transmitted light through the reference solution containing the solutions under study (pure dialysate + waste products from the blood) (9).
The obtained UV-absorbance values were processed and presented on a computer screen (Fig. 1) using Kontron software (UVIKON 943, version 7.0 for Windows; Kontron Instruments, Italy).

Data handling
Time and origin of the observed clinical events and manipulations were manually documented during the treatments and were examined in combination with the corresponding UV-absorbance recordings. All events were summarised in a table (Table 2) and exemplified in figures (Figures 3A-C) .

Results
Figure 2 shows a typical UV-absorbance curve measured at the wavelength of 280 nm during a haemodialysis treatment of 270 min. The UV-absorbance is plotted against time and drops and peaks, which normally occurs at predestined intervals during dialysis, corresponding to the self-tests of the dialysis machine (dialysate in by-pass mode).
Table 2 shows a summary of the events that were observed in UV-absorbance in all 108 treatments. In 53 treatments no alarm or disturbances occurred at all. The total number of events was 135. The most common event was a short blood pump stop due to low artery pressure alarm (n = 103) followed by conductivity alarms resulting in by-pass of the dialysate (n = 14).
Figure 3 presents clinical examples of UV-response. 3A visualises (a part of a session) the response in UV-absorbance during a blood pressure fall at 195 min and also the response during the immediate actions that were taken; ultra filtration (UF) off, supine position of the bed and oxygen mask delivery. At 225 min the Qb was adjusted to 200-ml/min and intravenous infusion was given and a recovery was observed in UV-absorbance. Finally the Qb was readjusted to 300 ml/min and UF was switched on. A broken line is also inserted to approximate the conjectured clearance decay.
Figure 3B shows a session with a conductivity alarm resulting in a 10-min by-pass of the dialysate. A short blood pump stop (a few seconds) also occurred at 50 min. These events were visualised in UV-absorbance variation.
Figure 3C shows a troublesome part of a treatment with a period of restricted blood flow in the artery needle due to malposition, with artery pressure below – 200 mmHg (from 70 to 170 min), and this was indicated by a decrease in UV-absorbance. The following three needle corrections during intervention resulted in an increase in UV-absorbance. The broken line is inserted to approximate the conjectured clearance decay.

Discussion
The result of this descriptive study shows that due to the high sampling rate the UV-absorbance is sensitive to different kinds of disturbances, e.g. alarm of conductivity (dialysate in by-pass) artery-, venous pressure (blood-pump stop) and restricted flow in artery needle due to low blood pressure or troubling needle placement. These events are rather common during dialysis treatment and occasionally it affect s dialysis clearance.
The high correlation between UV-absorbance and concentration of several waste solutes e.g. urea, creatinine and uric acid (9,10), and lower correlation to electrolytes in the dialysate (9), allows an assumption that the variation seen in UV-absorbance during dialysis is a good approximation of variations in clearance for these small solutes. High correlation to UV-absorbance has also been found in a pilot study for phosphate and beta-2 microglobuline (data not shown), which intimate the vision that other solutes significant for the dialysis patients may be estimated by the UV-method. If the concentration of a solute should be measured the millimolar extinction coefficient ε [m^-1 (mol/l)^-1] must be known for the solute at a specific wavelength ,according to Beer-Lambert law. But this is still difficult because not all compounds in the spent dialysate, absorbing UV-light, are identified (11) and probably they interfere with each other.
In Fig. 3A the UV-response to a blood pressure fall and the following interventions are shown. The UV-absorbance was lowered, even when Qb was unchanged (195-225 min), most certainly due to difficulties to achieve the pre-set Qb by the dialysis machine. The use of UV-absorbance shows the possibility to not only notify alarm effects as in Fig. 3B, but also to give direct feedback after interventions resulting in clearance changes as in Fig. 3C. New baseline levels in UV-absorbance were observed after the 10-min interruption in Fig. 3B and after the needle corrections in Fig. 3C. Manipulation of Qb and Qd has earlier been shown to have a very pronounced effect on the UV-absorbance ( 12).
The visualisation of the clearance process is a novel finding by the UV-method and one advantage of using a method with high sampling rate. However, Kt/V calculated from UV-absorbance using the slope of the natural logarithm (7) must be interpreted with care when there are great UV-variations corresponding to changes in dialysis parameters. The earlier clinical available Urea monitor 1000 (UM) from Baxter Health Corp. IL, USA, suggests a rejection of sessions with 5 or more urea measurements deviating from the expected decay (4). The clinical benefit of the UV-absorbance system would be to monitor troublesome treatments where dialysis clearance can be adjusted on-line , but this issue concerning the use of the slope when calculating dialysis dose needs further investigations by the UV-method.
The on-line urea monitors based on direct urea measurement, e.g. UM (4), have not found wide- spread use in clinical practice. Possible reasons could be high initial and running costs, need for disposals and extra work for the staff. The ionic dialysance tool on the other hand is easily integrated in the dialysis machine and suitable in the clinical environment, to a relatively low cost. It provides the ability to present an estimated urea-Kt/V close to the time of dialysis delivery (13). However, the role of urea as a marker of dialysis adequacy has been discussed and other molecules are under investigation (14,15). Besides urea, which reflects the dialysis adequacy of low molecular waste solutes, it has also been suggested the need to evaluate molecule groups of middle and protein bound solutes (14,15). On the other hand, the UV-method gives an on-line overview of the clearance process during dialysis reflecting several solutes in the spent dialysate and this is perhaps a more reliable approach to follow dialysis adequacy.

Limitation of the study
The patient group was not representative for a dialysis population due to the selection of stable patients, events only occurred in 55 of 108 treatments. This study gives an indication of what kind of events and the magnitude of disturbances that can be identified by UV-absorbance.
To perform an analytic approach to study interference that may occur with the UV-absorbance a logging computer should be used in future studies.

Nursing implications
Dialysis dose (urea Kt/V) correlates to morbidity and mortality (16,17) and the nurses performing dialysis treatments are important in the management of dialysis patients. They also contribute to achieving dialysis adequacy. For example, the nurses performing dialysis treatments can correct needles to adjust an optimal Qb indicated by acceptable artery and venous pressure values. With the UV-technique we can take one step further. Any kind of intervention (e.g. to optimise clearance) can be confirmed immediately on a screen. This approach may also be suitable for patients treated with home dialysis as a monitoring tool for the patient at home and as an evaluation by nephrologists and nurses at the hospital, i.e. if the UV-registration is sent electronically.

Conclusion
In conclusion this study demonstrates that it is possible to monitoring clinical events that may have an affect on clearance by using UV-absorbance measurement with a high sampling rate of the spent dialysate. The UV-method gives the opportunity to verify changes in clearance and the result of interventions in order to adjust a dialysis clearance value that can be confirmed directly on the screen. This new technique could be a helpful tool for the dialysis operator (nurse or patient) to approaching an adequate dialysis dose in the future.