Quality Nephrology Nursing Care: Beyond Kt/V

Abstract

Through a critical review of nursing and medical literature, this article argues that nephrology nurses have embraced Kt/V at the expense of other core elements of nephrology nursing care. The focus on quality care as technical expertise may dominate at the expense of interpersonal care. Nurses need to challenge the influence Kt/V has on other aspects of nephrology nursing care. [PUBLICATION ABSTRACT]

Headnote

Through a critical review of nursing and medical literature, this article argues that nephrology nurses have embraced Kt/V at the expense of other core elements of nephrology nursing care. The focus on quality care as technical expertise may dominate at the expense of interpersonal care. Nurses need to challenge the influence Kt/V has on other aspects of nephrology nursing care.

Ask nephrology nurses about the care in their hemodialysis units and they will probably say that high quality care is provided. This perception may reflect a genuine pride in their own and their colleagues' hemodialysis services, however, the meaning of high quality dialysis care remains unclear. Quality is often framed in terms of the high percentage of patients receiving a Kt/V of greater than 1.2 or 1.4. The unfortunate inference here is that high quality hemodialysis care is defined as the waste clearing service of the urea molecule. Defining quality in this narrow way conflicts with the caring and compassionate nursing ethic. Furthermore, it places a high value on a single mathematically derived formula that ignores many other indicators of quality dialysis care. In this article, the authors examine some historical, political, and technical features of Kt/V and use the metaphor of a hangover to illustrate the overuse of Kt/V, arguing that nurses have embraced Kt/V at the expense of other core elements of dialysis nursing care

Kt/V (Over)Use

Since Kolff's first successful human dialysis treatment in 1944, there have been attempts to identify a gold standard marker of dialysis dose. The first evidence of the quantification of dose was reported in 1951 by Wolf, Remp, Kiley, and Currie (Henderson, 2004). Further developments throughout the 1960s and 1970s culminated in the National Cooperative Dialysis Study (NCDS) which established that a single pool Kt/V (spKt/V) of less than 1.0 is associated with increased patient mortality (Gotch & Sargent, 1985). Kt/V can be defined as the amount of urea clearance (K) multiplied by time (t) and divided by urea distribution volume (V). Current KDOQI, European, and Australian nephrology guidelines (CARI) suggest that the target dose of dialysis is a single pool Kt/V (spKt/V) of 1.4 or a urea reduction ratio (URR) of 70% (Kerr, Perkovic, Petrie, Agar, & Disney, 2005).

The acceptance and application of Kt/V as the measure of choice in the delivery of dialysis has been reflected in the large amount of medical literature committed to it. There has been far less discussion devoted to criticisms of Kt/V and to encouraging an approach to quality that includes more than Kt/V. Twardowski (2003 a,b) encouraged the implementation of other priorities in dialysis treatment such as blood pressure control, longer treatment times, limited ultrafiltration rates, absence of phosphate binders, normalized pre-dialysis bicarbonate and potassium levels, well-nourished patients, avoidance of inflammatory stimulation, and the minimization of middle molecules. Optimizing patient quality of life falls second to incenter, prescription-focused treatment schedules. Dialysis care requires caring clinicians with a high level of interpersonal skills who realize the unique individual needs of each patient on dialysis (Henderson, 2004). However, the above arguments discussing alternative measures of quality have been dominated by the literature examining the most accurate methods for measuring Kt/V (Bosticardo, Avalle, Giacchino, & Alloatti, 1995; Covic, Goldsmith, Hill, Venning, & Ackrill, 1998; Daugirdas, 1993; Kovacic, Rogulijic, Jukic, & Kovacic, 2003; Maduell et al., 1997; Yanai et al., 1993; Ziolko, Pietrzyk, & Grabska-Chrzastowska, 2000).

The current use of Kt/V as the quality indicator of choice is an example of the development of knowledge influenced by doctors, scientists, and nephrology nurses. We concur with Blake (2003) who suggested that Kt/V has been embraced enthusiastically because it is scientific and measurable, and that few people (particularly patients) other than doctors, scientists, and nurses understand it. The measurable characteristic of Kt/V has been appealing to administrators, managers, and quality coordinators because of its ease of measurement and reporting characteristics. Furthermore, as nephrology clinicians, we can point to the benchmarked target outcomes presented in various international guidelines such as KDOQI, CARI, and European Best Practice Guidelines (European Renal Association, 2006; Kerr et al., 2005; National Kidney Foundation, 2001, 2006). From a clinician's perspective, Kt/V is the ideal quality indicator, but it can mystify patients and result in a lack of understanding by patients, which can create unequal power relationships in hemodialysis units.

The Power of Kt/V

There are complex power relationships among the stakeholders in hemodialysis care. We argue that the use of Kt/V, as a technical, complex construct contributes to the superior scientific knowledge and power inequalities already evident in the dialysis environment among powerful nephrologists, less powerful dialysis nurses, and least powerful patients. Furthermore, we believe that complex mathematical formulas for Kt/V (see Table 1), which are understood by the most powerful stakeholders, can be used to control the least powerful - patients.

Bevan (2000) compared the dialysis unit to a prison incorporating prison cells (patient, chair, machine) and a watchtower from where the nephrologists and nurses gaze. Bevan's Foucauldian perspective is important for the discussion here of Kt/V and power. He compares a patient on dialysis to Foucault's prisoner, who is: "seen, but he does not see: he is an object of information, never a subject of communication" (Foucault, 1977, p. 200). Nephrologists and nephrology nurses sometimes decide the prescription or Kt/V without including the patient. In an Australian study, Tims (2006) found that in the dialysis unit, patients (unless on home dialysis) have little say in their dialysis prescription or they are talked over, and may not attend their own patient care meeting. Furthermore, they are rarely allowed to document in their medical case notes.

Patients' quality of life is influenced by and dependent upon the service of specialized nephrology service providers (Gregory, Way, Hutchinson, Barrett, & Parfrey, 1998; Hagren, Pettersen, Severinsson, Lutzen, & Clyne, 2001; van der Sande, Kooman, Laurie, Gommers, & Leunissen, 2003). This creates major power differences between patients, nephrologists, and nurses. Dialysis nurses spend the most time with patients and have become their decision makers (Price & Paganini, 1999; Stewart & Bonner, 2000), but the nurse's role has not been linked clearly with improved patient outcomes (Lee, Chang, Pearson, Kahn, & Rubenstein, 1999). For example, nurses who work in dialysis units have embraced the use of the Kt/V for similar reasons to nephrologists; that is, it is scientific, measurable, and leads to patients living longer. Unlike many nephrologists, however, dialysis nurses have not been vocal in challenging the limitations of urea as a measure of quality dialysis care.

We believe nurses have taken this reliance on Kt/V too far and need to emerge from what we have termed a Kt/V hangover. It has become a hangover because new evidence has emerged to challenge Kt/V, yet nurses have not been able to emerge from their intoxication with the science of Kt/V. Such is the power of Kt/V among the stakeholders in dialysis care.

The Consequences of (Over)Use Of Kt/V

The popularity of Kt/V as the predominant marker of quality has consequences that may affect patient outcomes. An example of this is the poor outcomes of smaller patients who were meeting the Kt/V targets but were undernourished and underdialyzed (Lowrie, 2000). Lowrie's alternate Kt/V proposal and discussion of the reversed J shape drew him to conclude that "existing urea kinetic constructs cannot lead to appropriate outcome-based measures of dialysis dose" (Lowrie, 2000, p. 293). Furthermore, it has been proposed that the mathematics of Kt/V calculation have distracted us from more important questions relating to improving dialysis care (Briggs, 2004; Lowrie, Ofsthun, & Lazarus, 2002). Blake (2003) suggested that urea may not be a good surrogate for the toxins that matter. Other nephrologists agree that urea based measures have their limitations (Twardowski, 2003b; Vanholder, DeSmet, & Lesaffer, 2002) and have, in fact, impeded our ability to achieve optimal dialysis (Cohen, 2000). Added to the chorus of discontent are the results of two landmark randomized clinical trials, HEMO (Eknoyan et al., 2002) and ADAMEX (Paniagua et al., 2002), which challenge the hypothesis that the more doses the better (Himmelfarb, 2006). It is clear that doubts are emerging relating to the (over)use of urea in the form of Kt/V as the indicator of the quality of our dialysis treatment.

Preoccupation with Kt/V by nephrology professionals has resulted in deflecting time and energies away from meaningful patient care priorities. The clearest presentation of this was by Boag (1999), who proposed that the current method of numbers and guidelines coming first, published data second, and the individual patient third, should be turned around, with the individual patient at the forefront. Two eminent nephrologists, Scribner and Oreopolous (2002, p. 15), suggested that, for the experienced patients on dialysis, the most important measure of enough dialysis dose is "how they [the patients] feel." Although Kt/V is considered a practical tool to quantify dialysis, there have been criticisms of overusing urea as the major measure of uremia (Canaud, 2004). Despite providing the required Kt/V, adverse complications such as cramps, nausea, vomiting, fatigue (Twardowski, 2003a) and underdialysis (Scribner & Oreopolous, 2002) have still occurred.

There is recognition in the nursing literature that Kt/V has limitations (Bednar, 1991; Bevan, 2000; Ran & Hyde, 1999) and there is support for nontechnical aspects of care (Giacchino, Manzato, De Piccoli, & Ponzetti, 2000; Polaschek, 2003; Richard, 2006), but we argue there is a need for more critical debate in the nursing literature. The earliest reported published nursing article that deals solely with kinetic modeling and nursing was by Fulcomer in 1981 with the majority of the early literature addressing the "technical" role nurses played in the process of urea kinetic modeling (Terrill, 1990; Threlkeld, 1992). Recent contributions have explored the relationship between quality of life and dialysis dose (Cleary & Drennan, 2005; Hamilton & Locking-Cusolito, 2003; Morsch, Goncalves, & Barros, 2006) but have not critiqued the Kt/V construct. Furthermore, nurses have not been as vocal as nephrologists in their cautionary Kt/V writings (Henderson, 2004; Scribner & Oreopolous, 2002). Therefore, we encourage nurses to critically evaluate quality measures to avoid limiting their measure of quality to simply urea reduction measures such as Kt/V.

Nephrology Nurses Need to Change

Nephrology nurses need to decrease their emphasis and reliance on Kt/V as an indicator of quality hemodialysis care. In dialysis units today, we have technology such as online urea and fistula recirculation monitors. Supporting the dialysis machine, we have sophisticated software to analyze dialysis dose in the form of Kt/V or URR and, at the click of a button (or a mouse), we can benchmark our unit's measures locally, nationally, and internationally. This is very attractive, but is it achieving quality hemodialysis care for our patients? We suggest that using Kt/V in isolation provides little benefit for the patient.

Increasing emphasis on technical measures such as Kt/V creates the illusion for patients that we are competent, but it conceals the reality that we do not know why the patients feel so unwell before, during, and after dialysis. We really do not know, and sometimes do not ask, why they finish dialysis and go home to sleep and why they feel fatigued for the rest of the day. The lure of technology for nursing is enticing (Bevan, 1998; Peplau, 1962; Polaschek, 1998) and, combined with a mathematical formula for Kt/V, this technology can be irresistible. Nurses are the key to delivering the adequacy of the dialysis treatment (Bednar, 1991). We continue to use larger dialyzers and increase blood flow rates to obtain higher Kt/Vs. Worse still, the excessive emphasis nurses place on high Kt/Vs lures unsuspecting patients to request higher Kt/V, which we acknowledge to keep them satisfied. These requests are our suggestions, but we create an illusion of allowing patients to direct their own care when we are actually dictating their care.

Decreasing the Emphasis on Kt/V - We Can Change

We can be better nephrology nurses and give even higher quality nursing care to patients on hemodialysis by decreasing our emphasis on Kt/V. Nurses need not be seduced by mathematics or technology and become "technically enframed" (Bevan, 1998, p. 735). Excellence in our care is evidenced by enabling patients to promote well being in order to achieve a higher quality of life. This can be achieved through improved communication (Giacchino et al., 2000); negotiated care (Polaschek, 2003); interpersonal competence (Gregory et al., 1998); empathetic, supportive relationships (Ran & Hyde, 1999); maintaining a human focus (Bevan, 2000); empowerment (Lundin, 2000); and partnerships (Ashwanden, 2003). Focusing on strategies that encourage patients to achieve their own goals rather than our Kt/V goals may contribute to improved outcomes for patients on dialysis.

The great shame of our emphasis on Kt/V is that it has distracted us from where we can really make a difference. We can really make a difference in patient outcomes by encouraging patients to consider frequent, longer, or nocturnal dialysis (Kooistra, 2003; Ouwendyk, Leitch, & Freitas, 2001). Nurses are the numerically dominant clinicians and can be the key to changing existing structures that restrict the uptake of frequent and nocturnal dialysis (Bennett & Oppermann, 2006). Nurses are best positioned to improve the quality of 'care' not just the quality of 'cure.'

Implications for Nephrology Nursing Practice

Challenging the accepted role of Kt/V has implications for nursing practice and research. Incorporating more than Kt/V in our practice models will assist us with the complex challenge of providing an alternative to the Kt/V nursing hangover. There is no absolute right approach, but to submit to a universal approach is against nursing's holistic concept. It is not quality nursing. A systematic but individualized approach (Batter, 2003; Sehgal, 2002) placing the patient's experience first, and then being guided by their numbers (Boag, 1999) is a quality nursing approach. We need to embrace a far more complete picture of uremia that includes fluid and salt control; blood volume and blood pressure control; bone disease control; nutrition; middle molecule clearance; intradialytic and interdialytic symptoms; patient's goals; and the minimization of co-morbidities, morbidity, and mortality. We need to go beyond Kt/V to achieve the goal of patient well-being (Cohen, 2000). Nurses are fundamental to achieving this goal and it is now up to us to cure our own Kt/V hangover. Further research to assist nurses to provide quality dialysis nursing care will contribute to the aim of limiting our current reliance on Kt/V.

Summary

This critical commentary on Kt/V (over)use has been designed to encourage debate and discourage nurses from following powerful, but questionable, science in the name of quality dialysis nursing care. We have been intoxicated by the Kt/V formula and its power to direct dialysis care. Many of us are still suffering the effects of the Kt/V hangover. Nephrology nurses need to apply individualized, patient-focused care and not simply use a single universal quantifiable measure of quality hemodialysis care, in order to cure the Kt/V hangover.

Nephrology nurses need to change from a sole focus on the questionable measure of Kt/V to incorporating a range of ways patients can be involved in their own care. We need to listen to the patient's own prescription. We need to provide nursing care that complements the patient's own goals and not rely on an adequate prescription for urea clearance. Changes in our care are needed, but may not occur if we avoid the often unrecognized power differences evident in the dialysis environment, where the patient is the least powerful partner in their own care.

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