Commentary on Kaitani T, Tokunaga K, Matsuu N & Sanada H (2009) Risk factors related to the development of pressure ulcers in the critical care setting. Journal of Clinical Nursing19, 414–421


  • Zena Moore

    1. Author:Zena Moore, PhD, MSc, FFNMRCSI, PG Dip, Dip Management, RGN, Faculty of Nursing & Midwifery, Royal College of Surgeons in Ireland, Dublin, Ireland
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Zena Moore, Faculty of Nursing & Midwifery, Royal College of Surgeons in Ireland, 123 St Stephen’s Green, Dublin 2, Ireland. Telephone: 00 353 1 4022 414.

Pressure ulcers are a significant health care problem despite considerable investment in education, training and prevention equipment (EUPAP 2002). European figures suggest that up to 23% of all hospital in-patients have a pressure ulcer; furthermore, most pressure ulcers occur during hospitalisation for an acute episode of illness/injury (EUPAP 2002). The impact of pressure ulcers on the individual is profound, affecting all domains of the activities of living (Gorecki et al. 2009). The costs associated with the prevention and management of pressure ulcers are also considerable, with one of the main cost drivers being nursing time (Posnett & Franks 2008). Changing demographics predict an increase in the older population; therefore, because of the likelihood of an associated increase in health care problems, it is probable that the number of individuals with pressure ulcers will also increase.

Risk assessment is the first step in planning pressure ulcer prevention strategies. The purpose of risk assessment is to identify those at risk of pressure ulcer development, by identifying key factors considered important. Following this assessment, effective prevention interventions should be planned and implemented. To identify which individuals are at risk of pressure ulcer development, it is first necessary to understand what is meant by risk. Risk has been defined as the probability of an individual developing a specific problem, i.e. a pressure ulcer (Deeks et al. 2002). Interventions employed to combat risk are often expensive and health care resources are finite; therefore, accuracy in identifying those patients who need prevention strategies is critical. Many authors have attempted to identify the factors that influence the development of pressure ulcers and have summarised these factors into risk assessment tools for use in clinical practice (Gosnell 1973, Lothian et al. 1976, Waterlow 1985, Braden & Bergstrom 1987). This has proved a difficult task as there are a vast number of potential risk factors. Indeed, a very early review of 100 pressure ulcer articles by Gosnell (1988) identified a possible 126 risk factors.

Despite the apparent lack of clarity regarding what precisely predisposes an individual to risk, what appears to be central is that pressure ulcers will only develop if the individual cannot withstand the adverse effects of pressure and shearing forces (Defloor 1999). This ability had been defined by Braden and Bergstrom (1987) as the person’s ‘tissue tolerance’, which they suggest is affected by both intrinsic and extrinsic factors. It is this background that forms the basis for the study by Kaitani et al. (2009).

The authors (Kaitani et al. 2009) suggest that disease severity may be the most important risk factor for pressure ulcer development in the critical care setting and therefore, set out to explore this among a cohort of 240 patients in an ICU/high dependency unit in Japan. Interestingly, using multiple regression analysis, disease severity did not emerge as a statistically significant risk factor, rather repositioning and turning were statistically the most important variables (Kaitani et al. 2009). In the study by Kaitani et al. (2009), the participants were those individuals who demonstrate significant problems with mobility.

Healthy individuals regularly change their position whilst seated or recumbent. Indeed, Keane (1979) suggested that the minimum physiological mobility requirement (MPMR) to maintain healthy tissue, whilst lying on a soft mattress, is one gross postural change every 11·6 minutes. This MPMR is based on observations of average individuals repositioning frequencies during sleep. Allman et al. (1999) agrees that the association between limited activity and mobility remains an important consideration as highlighted in the seminal work of Exton-Smith and Sherwin (1961). In this study (Exton-Smith & Sherwin 1961), the authors found that the amount of spontaneous nocturnal movements of older individuals was positively related to the development of pressure ulcers. As the number of movements increased, the number of pressure ulcers decreased. Patients who make 50 or more movements had no pressure ulcers, whereas 90% of patients who made 20 or fewer movements developed ulcers (Allman 1997).

Pressure, from lying or sitting on a particular part of the body, results in oxygen deprivation to the affected area (Defloor et al. 2005). There are normally several stimulators, during sleep and whilst awake, that motivate the individual to move (Defloor et al. 2005, Krapfl & Gray 2008). Failure to reposition will result in ongoing oxygen deprivation and inevitable tissue damage (Husain 1953, Kosiak 1959). Repositioning is affected by the individual’s ability to feel pain and the individual’s actual physical ability to move or reposition themselves (Defloor et al. 2005). The cohort of patients who participated in the study of Kaitani et al. (2009) are those who are most likely to be sedated and as such unable to feel the need to reposition or indeed, unable to physically reposition themselves. In the absence of the patient having the ability to reposition, they require assistance. Indeed, the central link between immobility and pressure ulcer development is well founded in the literature (Bergstrom et al. 1996, Goodridge et al. 1998, Casimiro et al. 2002, Moore 2008). As pressure ulcers occur because of prolonged unrelieved exposure to externally applied mechanical forces (Kosiak 1959), it is logical that activity and mobility are the highest predictors of risk, as it is these factors that cause an individual to be exposed to pressure.

Traditionally, the first component of prevention was risk assessment and over the years an increasing array of risk assessment tools has become available (Moore & Cowman 2008). Fundamentally, it is questionable why so many tools are in use if they are all supposed to be measuring the same concept. Indeed, as argued by Anthony et al. (2008), if there were one perfect tool, then there would not be a need for all the others. Practically, the lack of agreement regarding risk assessment is a challenge for those in clinical practice and this challenge is compounded by the vast number of risk factors cited in the literature. If the risk assessment process has become so complex, then one must question its clinical relevance, particularly in today’s health care environment where a lack of time and staff are frequently cited barriers impeding practice (Moore & Price 2004, Jordan et al. 2009). Further, the literature has shown that staff often favour the use of clinical judgement over a risk assessment tool (Saleh et al. 2009). Indeed, decision making is frequently not based on the outcome of risk assessment rather is influenced by other extraneous, as yet unrecorded, variables (Saleh et al. 2009).

Whilst acknowledging that, in the main, one is assessing the individual at the macro level, rather than at a cellular level, which is clearly not captured during the traditional risk assessment process, it is contended that the process of risk assessment needs to be revisited. Pressure is the prime cause of pressure ulcers (Bader 1990) and those who are exposed to pressure are those who are immobile and cannot relieve pressure from bony prominences (Fisher et al. 2004). Therefore, it is logical that the first question to ask is whether the patient can move independently or not. If problems regarding mobility and activity are identified, then the remaining process of risk assessment should ensue. If no problems regarding activity and mobility are noted, then the patient is unlikely to develop a pressure ulcer.

Having identified risk of pressure ulcer development because of activity and mobility problems, the objective is to develop an appropriate plan of care to ensure the safety of the individual (Moore & Cowman 2008). This in itself is a challenge, as there are many recommendations in the literature; however, often these are conflicting and largely do not serve to clearly guide practice (Moore & Cowman 2009). As with risk assessment tools, the number of pressure redistribution devices available has increases year-on-year (McInnes et al. 2008). The evidence base to support the use of these products is weak and furthermore, although often advocated, they do not replace the need for repositioning the patient (Krapfl & Gray 2008). The use of repositioning has lost favour in many instances, with the argument contended that it is time consuming and costly in terms of personnel (Defloor et al. 2005). However, this argument is not based clinical evidence; furthermore, the presence of a pressure ulcer is in itself a major cost driver in terms of health and social gain, thus a cost benefit analysis of repositioning for prevention needs to be undertaken.

The role of repositioning has been discussed in the literature for centuries, with the first recording being that of Robert Graves in 1848 (Sebastian 2000). Although it makes logical sense that repositioning will make a difference to pressure ulcer incidence, the challenge lies in determining how the patient should be repositioned and how often the position be altered. In the strive for evidence-based practice, the role of repositioning does not fit well as there is a clear lack of scientific evidence available to support its practice. This point is highlighted by Kaitani et al. (2009) who refer to the Agency for Health Care Policy and Research guidelines (1992) as the basis for best practice in repositioning, despite the lack of clear guidance in these guidelines. There are only two studies that have explored the role of repositioning in prevention within the clinical setting to date (Defloor et al. 2005, Vanderwee et al. 2007) and none that have determined its effect in treatment (Moore & Cowman 2009). The two studies of prevention have methodological issues, such as confounding extraneous variables which may be exerting an effect and similarities between the control and experimental groups, which influence the confidence in which one may have on the study outcomes.

It is clear that activity and mobility scores are important considerations in the identification of those who are at risk of pressure ulcer development (Bergstrom et al. 1996, Goodridge et al. 1998, Casimiro et al. 2002, Moore 2008). Adopting a more focused approach to risk assessment may yield greater outcomes, in that prevention may be targeted where it is most needed. Pressure ulcers are common, costly, impacting negatively on the individual’s health related quality of life and on the ability of the health service to deliver a cost effective, efficient service. Pressure ulcer can be prevented by determining those who are most at risk and the implementation of effective prevention strategies. The authors (Kaitani et al. 2009) argue that more frequent repositioning may be an important consideration in terms of pressure ulcer prevention within their cohort of patients. This argument makes logical sense because immobility is the prime risk factor that exposes an individual to the cause of pressure ulcers and as such the focus of risk assessment should begin with this factor. Pressure ulcers will continue to remain a significant problem unless investment is placed in prevention; however, as yet, the exact frequency and method of repositioning has to be established.