DOCTOR OF NURSING RESEARCH PORTFOLIO

Transcription

1 DOCTOR OF NURSING RESEARCH PORTFOLIO Pressure Ulcer Prevention in the Perioperative Environment Ms Judith Berry RN BN MN Submitted in fulfilment of the requirements for the Degree of Doctor of Nursing Department of Clinical Nursing University of Adelaide August 2004

2 TABLE OF CONTENTS Page Certificate 2 Acknowledgments 3 Portfolio Overview 4 References 7 1

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4 There have been many people who have provided encouragement, support and advice during the completion of my studies, and I wish to acknowledge them, for without them the road would have been just that bit more difficult. Dr. Helen McCutcheon, supervisor and friend for her guidance, encouragement and confidence to succeed. Dr. David Evans, always patient, whose assistance through the critical review was invaluable. Dear Pat, whose keyboard skills have supported me from the very beginning to now my swan song! To Marion, friend and fellow student, always calm and rational. Lastly, my thanks to those nurses who participated in the research and went out of their way to support the project, and those who simply gave a kind word and had faith in my ability to succeed. Photograph of Operating Room, Royal Adelaide Hospital reproduced with kind permission by the History & Heritage Office, RAH. 3

5 Portfolio Overview There are many terms used to describe pressure ulcers: pressure sores, decubitus ulcers, bedsores, and pressure necrosis or ischaemic ulcers. Essentially they all describe damage to the patient s skin and underlying tissue. The nursing literature abounds with information about the risk, grading, prevention and treatment of pressure ulcers. These ulcers are a problem in hospital and long term care facilities, and are a major cause of morbidity. In the hospital setting they contribute to an extended length of stay and by doing so block the bed for use by another patient. The ulcers are difficult to treat, are an ongoing cause for pain and discomfort for the patient and can be a strain on hospital finances. Pressure ulcers are not unique to modern times, as they have been discovered on the remains of an Egyptian mummified body (Armstrong & Bortz 2001). This would suggest that the problem dates back to the Pharoahs, and has continued to be a challenging problem throughout the centuries (Bridel 1992). The escalating costs of treating these ulcers today, has brought about an emphasis on the risk factors, prevention and the appropriate interventions, rather than an acceptance of these ulcers as a tolerable condition (Bridel 1992). In the operating room, nurses are faced with unique challenges when caring for their patients. This is due to difficulty in caring for patients under the influence of the anaesthesia required for surgery, long periods of forced immobility and the inability of the patient to perceive pain and discomfort from the pressure of the hard surface of the operating room table. These problems are increased by nurses inability to gain access to the patient because of the sterile drapes required to cover the patient for surgery. Armstrong and Bortz (2001) present information from one study in which it is stated that surgical patients have 90% greater chance of developing pressure ulcers than medical patients. One reason for this may be due to the limited information available in regard to the most 4

6 effective support surface to place on top of the operating room table. This gap in information is problematic for operating room nurses as it limits their ability to select the most effective item of equipment, and determine if the chosen equipment reduces pressure on tissue intra-operatively. The most effective operating room table mattress used and the skills and knowledge of the operating room nurse about the aetiology and prevention of pressure ulcer prevention, are important aspects of nursing care and can influence patient outcomes. The potential for complications to occur may be dependent on single or combined factors such as the patient s age, disease processes, nutritional status and mobility. Preparatory and supportive nursing interventions for surgical procedures based on best available evidence, nursing experience and patient preference, can reduce the incidence of pressure ulcer development in the perioperative environment. This doctoral portfolio contains four separate sections related and linked together by a common theme pressure ulcer prevention in the perioperative environment. This first section of the portfolio situates the topic and provides a brief overview of the portfolio. The second section is a critical review of the literature pertaining to the most commonly used operating room table mattresses, and the effectiveness of these mattresses in the prevention of pressure ulcer development. This review highlighted a lack of quality research in this area, and while many evaluations have been undertaken to determine the effectiveness of operating room table mattresses, the results are contradictory concerning the patients, exposures and interventions. Because of issues related to the methodological quality of published research in this area a systematic review using meta-analysis was not possible rather a critical review of the research literature is used. 5

7 The third section of the portfolio reports on a hermeneutic ethnography of the perceived skills and knowledge of nurses in the prevention of pressure ulcer development in the perioperative environment. This study was designed to determine if pressure ulcer prevention forms an aspect of the everyday practice of perioperative nurses. This review has highlighted the need for operating room nurses to review practices when caring for patients in the perioperative environment particularly in respect of pressure ulcer prevention. The fourth and final section of the portfolio summarises the research and provides recommendations for nursing practice and further research in the area of pressure ulcer prevention in the perioperative environment. 6

8 References Armstrong D., Bortz P. (2001) An Integrative Review of Pressure Relief in Surgical Patients. American Operating Room Nurses Journal. March 73 (3): (p. 5). Bridel J. (1992) Pressure sores and intra-operative risk. Nursing Standard. October. 21 (7):

9 Pressure Ulcer Prevention in the Perioperative Environment: A Critical Review of the Literature

10 INDEX Page ABSTRACT 1 How it all began 2 Rationale for the Critical Review 3 Background 3 Historical Perspective 7 Aetiology of Pressure Ulcers 8 Pooled solutions for skin preparation 10 Skin shearing and friction occurring during positioning 10 Intra-operative hypotension 10 Alteration in haemodynamic and circulatory status 10 Tissue Tolerance for Pressure 11 Intrinsic factors 11 Extrinsic factors 11 Intensity and duration of pressure 11 Pressure Ulcer Classification Systems 12 Risk Assessment Tool 12 Incidence and Prevalence of Pressure Ulcers 13 Summary of the Background 14 Introduction 16 Pressure-relieving interventions 17 Critical Review Process 22 Objective 22 Methods 22 Types of studies 24 1

11 Page Search Strategy for Identification of Studies 25 Assessment of Methodological Quality 26 Data Collection 27 Data Analysis 28 Results 28 Standard Foam Operating Table Mattress 30 Findings 31 Results 32 Foam Pads 37 Results 38 Gel-filled Mattress 42 Results 46 Gel-filled Pads 51 Results 51 Overlays 53 Results 53 Discussion 56 Implications for Practice 58 Conclusion 62 References 65 Appendix 1 Inclusion Criteria = Elderly Perioperative Patients 71 Appendix 2 Critical Appraisal = Perioperative Patients 72 Appendix 3 Data Extraction Form 73 Appendix 4 Summary of major studies included in the study 76 2

12 Page Appendix 5 Excluded studies 82 Appendix 6 Hand searched reference books 84 Appendix 7 Hand searched journals 85 Appendix 8 Hand searched conference proceedings 86 Tables Table 1 Norton Scale Scores of 14 or below, rate the patient as at risk 13 Table 2 Standard Foam Mattress 32 Table 3 Standard Foam Mattress and Dynamic multi-cell mattress 33 Table 4 Standard Foam Mattress and Dry visco-elastic polymer mattress 37 Table 5 Evaluation of Foam Pads 39 Table 6 RCTs - Gel-filled Mattress 44 Table 7 Alternating air device, dry visco-elastic (gel-filled mattress 50 and standard foam) Table 8 Evaluation of gel-filed pads 52 Table 9 RCTs Overlays 55 Figures Figure 1 Meta-analysis of the micro pulse system 34 3

13 ABSTRACT Pressure ulcers are a pervasive problem in hospital environments, causing great distress to the patient and family and are a major cause of morbidity and prolonged hospital stay. The intraoperative situation is one period of greatest risk of pressure ulcer development for the surgical patient as body tissues are subjected to pressures which are applied in a non-uniform manner. The result is often localised tissue damage, and if the unfavourable conditions are prolonged, necrosis, tissue breakdown, and the development of a pressure ulcer occur. Unfortunately, operating room tables are designed for utility not comfort and to maximise the ability of the surgeon to expose and manipulate the surgical wound. Conventional operating room table mattresses are generally composed of two inches of foam, covered in thick black hard laminated vinyl fabric, considered as a standard fitting, with little evidence to suggest it assists in the prevention of pressure ulcer development. This critical review was conducted to summarise the best available evidence on the most effective operating room table mattress in pressure ulcer prevention. 1

14 How it all began: The Pressure to Bear A chance conversation between the researcher and a surgical registrar as they discussed the order of patients for surgical interventions the next day, was the catalyst for the study. When remarking on the perceived increase in the number of patients scheduled for skin grafting procedures to pressure ulcers in the past few weeks, the registrar replied this is just the tip of the iceberg, there are some (patients) out there (ward areas), who are not as bad as these, but do have them! The researcher continued to question the registrar further, enquiring if the patients had undergone surgery recently, had been admitted from nursing homes, or had in fact, been admitted from home. The response was, all following surgery except one. This was a real cause of concern and many questions arose from that conversation. was their surgery a long procedure, what were the patients positioned on for surgery, had extra equipment been used in an attempt to reduce pressure and had not proven to be effective, what steps had the nurses taken, if any to prevent pressure ulcer development, what did the nurses know and understand about pressure ulcer prevention. One thing these patients all had in common was the surface of the operating table, the other was nursing actions. It was at this stage that the decision to investigate the most commonly used operating table mattresses used in the study setting, the skills and knowledge of nurses caring for patients in the environment and their responsibility in pressure ulcer prevention was made. Regardless of the terms used to describe these ulcers, they remain a significant problem in both hospital and community settings. The need to reduce the incidence has been well documented; unfortunately there is little evidence to suggest any major new improvements have been made. 2

15 Rationale for the Critical Review When the literature was searched and read it became clear that few if any of the studies would meet the inclusion criteria and methodological quality required for a systematic review. Bearing this in mind and cognisant of the need to present the available research in a rigorous manner, a decision was made to undertake a critical review of the literature. Mulrow and Cook (1998) consider a critical review to be the qualitative equivalent of a systematic review. However much debate continues about levels of evidence and the value of interpretive research that are not within the scope of this study. Rather the researcher decided to present the research available in the most suitable way, in this case as a critical review of the literature on pressure ulcer prevention in the perioperative environment. Background Over the years much has been discussed, written and published, about the development and prevention of pressure ulcers, however a literature review of intra-operative pressure ulcer development suggests that there is a casual relationship between the events experienced by the patient during surgery, and the subsequent development of pressure ulcers (Gendron 1980, Stotts 1988, Bridel 1992, Bridel 1993a, Bridel 1993b). Abundant literature spanning health care settings and various specialties reveals that it is cost-effective to focus on the prevention of pressure ulcers rather than the treatment of them. Yet despite there being a general consensus that pressure ulcers are adverse events that on the whole are largely preventable, they continue to be a problem in all health care settings. The outcome implications of these ulcers should be considered in terms of pain and discomfort, decreased mobility, a loss of independence, and a potential source of social isolation for the patient, distress for family and friends in addition to the resource implications. Armstrong and Bortz (2001) present information from one study, in which it is stated that patients who undergo surgical procedures have a 90% greater chance of developing pressure ulcers than 3

16 medical patients. Recommendations for the care of the patient during the intra-operative period are limited to the provision of equipment for operating room tables which do not impinge upon the stability of the patient s position, safety, anaesthetic or surgical requirements (Horschowsky & Schraam 1994). There are a number of inherent risk factors that have direct correlation to pressure ulcer development, namely the age of the patient, their nutritional status, body temperature, co-morbidity, mobility status and body size, the most statistically significant intrinsic factor, is the age of the patient (Armstrong & Bortz 2001). When the age of the patient is combined with at least one other co-morbidity, conditions such as hypertension, vascular or respiratory disease, or diabetes mellitis, then the chances of the elderly surgical patient developing a pressure ulcer is greatly increased (Armstrong & Bortz 2001). The skin of the elderly patient is relatively easy to damage, and great care is needed when handling or moving the patient. This is due to the ageing process that causes a thinning of the dermis with a reduction both of the tensile strength, in tissue perfusion and a lessening of sensation (Dellasega & Rothrock 1990). For these reasons, the elderly surgical patient presents a challenge to operating room nurses, who are required to implement all the skill and knowledge they have about pressure ulcer prevention, in order to minimise the risk of the development of ulcer and skin damage (Armstrong & Bortz 2001). Turning patients for pressure and shear relief is common practice in ward areas but is not practical for patients undergoing surgery because of sterile environment. Special support surfaces for weight distribution and alternating pressure also face a number of unique difficulties. Some of the newer surfaces that are conformal enough to provide even moderate pressure reduction risk, create some patient movement as various pressures are applied to the patient through the contact with members 4

17 of the surgical team performing surgical manoeuvres (Aronovitch, Wilber, Slezak, Martin & Utter, 1999). Others tend to raise the height of the operating room table and this can make surgery difficult for the surgeon and those assisting with the procedure, as they may be required to stand on platforms / stools in order to access the open wound. For these reasons finding surfaces that are effective in reducing the risks of pressure ulcer development, whilst at the same time providing stability for both patient and surgeon during the surgical intervention, is difficult (Aronovitch et al 1999). One of the better materials available is a two-layered polyurethane foam. This is a synthetic material formed by combining liquid chemicals, which react together to form a long molecular chain process that ultimately results in polymerisation. A rising agent is then added and results are a honeycomb effect. An important indicator of foam quality is density and the higher the density the greater the durability of the item. The end result is a material that is soft, elastic, light and durable, takes up the contours of the patient and effectively evens out the distribution of the patient s weight, maximising the area over which the body weight is distributed and is reported to prevent ulcer development. Unfortunately this material is unavailable as a mattress for operating room tables (Huntleigh Healthcare 2001). Enquiries to the company in April 2003, about the development of an operating room table mattress in this material have not been answered. The standard operating room table is generally recognised as being a long, single piece of 1 2 inches of foam confined in a hard, thick non-stretch laminated fabric cover which is easy to clean, flame resistant and non-allergenic, however it does not reduce capillary pressure therefore does not prevent the development of pressure ulcers (Armstrong and Bortz 2001). The life expectancy of the standard foam mattress is limited, due to the constant flattening of the foam by the weight of the patient. Many types of mattresses have been developed from a variety of 5

18 materials and purchased by organisations on the recommendations of the manufacturers, often with little or no evidence that they prevent the development of pressure ulcers. It is unclear to what extent mattresses currently used in the operating room environment can prevent pressure ulcers and whether any one system is better than another. Although a number of assessment tools have been designed to assist in the prevention of ulcer development, these are on the whole unsuitable for use in the operating room where there is a need for complete immobility of the patient during surgical procedures. In other environments there is usually the opportunity to move the patient, albeit for brief periods of time. There is also the potential to use support surfaces which have the ability to vibrate gently, therefore stimulating skin, muscle and tissue, preventing stagnation of blood and bringing perfusion to the tissues, however this is not the case in the Operating Room (OR). Currently there is lack of nationally accepted guidelines, and evidence, in regard to the most appropriate operating room table mattress and this is of concern as this deficit allows the use of personal preferences, myths and traditional practices to determine the type of mattress use in the OR environment. A number of quality assurance studies conducted in the operating rooms have concluded that, Anaesthesia + low blood pressure + immobility + vascular compromise predisposes to tissue damage because cellular demands are not being met (Aronovitch 1999, p. 131). Whilst there is a number of publications addressing this issue, there does not appear to be an attempt to systematically collect, critically appraise and summarise current research. (Neander & Birkenfield 1991, Horschowsky & Schraam 1994, Aronovitch 1999a, Aronovitch 1999b, Defloor & deschnijmer 2000). 6

19 Historical perspective Pressure ulcers are not unique to modern times, as they have been discovered on the remains of an Egyptian mummified body (Armstrong & Bortz 2001). This would suggest that the problem dates back to the time of the Pharoahs and has been a challenging phenomenon throughout the centuries (Bridel 1992). Because of the escalating costs of treatment of ulcers, the emphasis is on prevention and the identification of risk factors, and the implementation of appropriate interventions, rather than acceptance of pressure ulcers as a tolerable complication (Bridel 1992). In the operating room environment the registered nurse is responsible for the positioning of the patient for surgery and the selection of positioning aids. It is therefore essential that the nurse maintains a current knowledge about the most efficient and effective mattresses and aids to use. However the operating room environment and its relationship to the prevalence of pressure ulcers for some patients have received little attention in contemporary research (Harley 2003). The activities that take place within the operating room environment are a cause for concern in terms of pressure ulcer development. Examples of this are issues such as pooled solutions, metal operating room tables, hard mattresses and the shearing and friction that may occur when moving the patient. Over the years researchers interested in pressure ulcer development have focused their attention on settings other than the operating rooms (Armstrong & Bortz 2001). The reasons for this are partly due to the difficulties encountered when attempting to extrapolate the results of studies conducted in the operating room environment to other areas, because of the specific risk factors associated with the operating room experience (Armstrong & Bortz 2001). Patients are often placed on positioning devices that make it difficult to estimate the degree of pressure exerted on parts of their body, and therefore make it problematic to obtain results that could guide practice. The Braden Scale (Braden & Bergstom 1987) is one tool used to assess patient risk in terms of pressure ulcer development and has been tested repeatedly for validity and reliability, but although useful in 7

20 the clinical evaluation of patients at risk of pressure ulcer development, it is not helpful in guiding effective interventions to reduce pressure during surgery. This tool and others, however, have not been tested in the perioperative setting where there is a lack of consistent turning schedule, immobility and inactivity, due to the requirements of anaesthesia and surgery. Previously damage to skin sustained in the operating environment was frequently attributed to a burn and overlooked by ward staff. The ulcer may not be apparent on completion of the surgery, and 3 to 5 days may pass before there are visible signs of tissue damage, mistakenly attributed to the procedure rather than to pressure. The subsequent development of lesions thought to be injuries are actually non-diagnosed pressure ulcers (Defloor & de Schuijmer 2000). Recently there has been a focus on the operating rooms as an etiological factor in the development of pressure ulcers. It has been suggested that all patients should be considered at risk for skin damage because of the risk factors that cannot / or are difficult, to control, such as length of the operative procedure (Armstrong & Bortz 2001). Aetiology of pressure ulcers For patients at risk of pressure ulcer development, compression of soft tissue between a bony prominence and an external hard surface for even a short time can result in damage to the tissue and eventually in a pressure ulcer. All levels of body tissue can be involved, epidermis, dermis, subcutaneous fat, muscle and at worse bone. The manner in which the pressure is applied requires consideration. If pressure is applied in a uniform manner then there may be little or no impact on tissue and skin surface. Damage occurs when pressure is applied to local areas such as patients elbows, sacrum and occipital regions. The duration and intensity of pressure to specific areas of the body has great variation and is related to other factors such as the individual patient s capacity to tolerate the pressure, whether or not they are thin, their age, oxygen saturation, diet, moisture, 8

21 physiological and psychological stressors and exposure to shear and friction (Russell & Lichtenstein 2000). Shear and friction occur when patients are not lifted from one surface to another, but dragged over rough surfaces, usually bed linen, therefore proper lifting and manual handling techniques are essential for patient transfers. Pressure ulcers arise over bony prominences, and the common sites include: Scapula, occiput, sacrum and heels when the patient is placed in the supine position, Ear, shoulder, trocanter, medial knee, ankle and foot edge when patient placed in the lateral position, and nose, forehead, chest, iliac crests, foot edge, and toes when patient placed in the prone position. (Armstrong & Bortz 2001, p. 647). There is an inverse relationship between time and pressure. Patients can usually endure a great amount of pressure during a short period of time, or minimum amount of pressure over a longer period without experiencing tissue damage. Neither time nor pressure alone causes damage (Armstrong & Bortz 2001). Prolonged pressure applied to a localised area of the body results in occlusion of blood flow causing tissue ischaemia and destruction. The elements of pressure ulcer development are the intensity and duration of pressure and the tolerance of the skin and its supporting structures for the pressure. Often damage to deeper structures may be far more extensive than observed at the skin surface (Pope 1999). Aronovitch (1999a) believes that many nurses in the ward areas, do not make any connection with surgical time and the development of ulcers post operatively, and are not familiar with the differences between traditional and intra-operative pressure ulcers, often describing the latter as unexplained burn like lesions, that are observed after lengthy surgical procedures that frequently and quickly deteriorate. 9

22 Of course there are other contributing factors and these include, Pooled solutions used to prepare skin Pooled preparation solutions may cause maceration to the skin, changing the ph of the tissue and in doing so remove protective oils, making the skin more susceptible to friction and pressure. Skin shearing and friction occurring during positioning Shearing and friction occurs when the outer layer of skin slides across a surface and consequently the tissue situated below the skin becomes damaged. These two factors require specific consideration in the operating room environment. This also occurs when the anaesthetised patient is moved on the operating room table without lifting them from the bed; the patient is dragged into specific positions. The result of this is twisting and tearing of the underlying blood vessels and this results in ischaemia and eventually necrosis (Waterlow 1996). Intra-operative hypotension Armstrong and Bortz (2001) report that in one study, a group of researchers found skin blood flow decreased by up to one half of the level measured during the preoperative phase of the patient s surgical experience, in patients who developed pressure ulcers. This change was due to the effects of anaesthetic agents that inherently interrupt and alter blood pressure, tissue perfusion and response to pressure. Alteration in haemodynamic and circulatory status related to the patient s position and blood loss An alteration in haemodynamic status and a deficit in perfusion, may lead to tissue hypoxia and an increase in the risk of pressure ulcer development. The severity of tissue damage is proportion to blood flow, and the defective response of the skin tissue (Armstrong & Bortz 2001). 10

23 Tissue Tolerance for Pressure Tissue tolerance is the ability of both skin and its supporting structures to endure the effects of pressure without adverse sequelae. It demonstrates how well the tissue acts as a cushioning factor, transferring pressure loads from the skin s surface to the skeleton below. Pressure can be defined as a perpendicular load or force exerted on a specific area of the body (Australian Wound Management Association 2001). When prolonged pressure is applied to that area, the tissue can be denied blood flow causing ischaemia and injury. Perfusion injury and the ischaemic changes, result in cell destruction and the death of tissue. If toxic substance removal is hampered this contributes to the tissue necrosis. This is affected by extrinsic and intrinsic factors. These factors will not cause tissue ulceration in the absence of pressure. Intrinsic factors These factors are inherent among patients undergoing surgical procedures, and exhibit a direct relationship in the prediction of pressure ulcer development the age of the patient, body temperature and nutritional status. Extrinsic factors These factors, when combined with the effects of the intrinsic factors, intensify the risk of developing a pressure ulcer; heat and moisture. Intensity and duration of pressure Braden and Bergstrom (1987) believe that the critical elements of pressure ulcer development are: the intensity and duration of pressure, and the tolerance of the skin and it s supporting structures for pressure. 11

24 Risk factors that contribute to the patient being exposed to prolonged and intense pressure can be classified as factors which impede mobility, activity, and sensory perception, with immobility and diminished activity being considered as primary risk factors in the development of pressure ulcers. Information from the Australian Wound Management Guidelines (2001) also indicates that any factor which exposes the skin to intense pressure, or diminishes its tolerance to pressure, is considered a risk factor. The surgical patient is exposed to all these factors throughout their surgical experience. There are many risk factors referred to in the literature, but few, such as operating table mattresses and tissue interface pressures, have been evaluated rigorously, and the operating room as an etiologic factor is largely undefined (Scott, Mayhew, Harris 1992, Harley 2003). Pressure ulcer classification systems Pressure ulcers are generally classified using a system designed to assess the degree of observed tissue damage. Using a classification tool it is hoped will allow for a universal assessment and consistent communication of the severity of tissue damage among nursing, medical and allied health care workers. Risk Assessment Tool The purpose of a risk assessment tool is to identify individuals at risk of developing pressure ulcers. The aim of any risk management strategy is to shift the focus from crisis intervention to preventative management. The risk assessment tools are based on risk factors known to predispose an individual to pressure ulcers. They generally utilise a numerical scoring system to weight the severity of risk into categories. These tools assist health care professionals to identify individual patients at risk, but they are not designed to replace clinical judgement. An example of an assessment tool is presented in Table 1. This tool by Norton was one of the first developed for use in the areas of geriatrics. It is simple, based on five areas, and utilises a scoring system which 12

25 indicates the level of risk. There have been some criticisms of it over the years, but it still remains one of the most widely used assessment tools (Bridel 1993). Table 1 Norton Scale Scores of 14 or below rate the patient as at risk. Name date Physical Condition Mental Condition Activity Mobility Incontinence Good 4 Alert 4 Ambulant 4 Full 4 Not 4 Fair 3 Apathetic 3 Walk/help 3 Sl. Limited 3 Occasionally 3 Poor 2 Confused 2 Chairbound 2 V. Limited 2 Usually 2 V. Bad 1 Stuporous 1 Bedfast 1 Immobile 1 Doubly 1 Total Score Source: Doreen Norton, Rhonda McLaren, and A.N. Exton-Smith An investigation of geriatric nursing problems in the hospital. London. National Corporation for the Care of Old People (now the Centre for Policy on Ageing). Incidence and Prevalence of Pressure Ulcers A great variation in reporting both the incidence and prevalence of pressure ulcers serves to demonstrate the inconsistencies in data collection and how pressure ulcers are classified and defined. If reliable data were available, the diagnosis and risk factors, incidence and prevalence of pressure ulcers by stage, and the environment in which the ulcer has arisen could be used to inform best practice (Pressure Ulcer Interest Sub-committee 2001). The incidence and prevalence of pressure ulcers is reported by a number of authors as varying widely according to the population, the clinical environment and research methodology used (American National Pressure Ulcer Advisory Panel 1989, Aronovitch et al 1999, Bridel 1993, Cullum, Deeks, Sheldon, Song & Fletcher 2000, Donnelly 2001, Komanestsky 2000, Australian Wound Management Association, Pressure Ulcer Interest Sub-group 2001). 13

26 A number of obstacles form the methodological barriers to the interpretation and comparison of incidence and prevalence of pressure ulcer studies namely: Difficulties in the comparison of the various patient populations, such as data collected from acute care facilities and community institutions. Sources of the data collected ranged from direct observations of patients by appropriately trained researchers to retrieval of information from medical records. Study results that may include or exclude ulcers classified as Stage 1, and sections of populations such as paediatrics and obstetrics. Study methods often confuse incidence and prevalence. Operating room table mattresses not covered in a manner that concealed the composition of the equipment so that true randomisation was not possible. (Hoshowsky & Schramm 1994, Nixon et al 1998, Cullum et al 2000, Australian Wound Management Association, Pressure Interest sub-group 2001). Summary of the Background Effective patient positioning has been a focal point throughout the history of surgery. Among the many benefits of proper positioning, preservation of the patient s skin is an important factor. Pressure ulcers are not unique to modern times, and even although there is abundant literature spanning various practice settings and specialties that reveal it is more cost effective to focus on prevention rather than treatment of the ulcers, the condition persists. Unfortunately most of the research focuses on the long-term care setting with little attention given to the operating room environment. Surgical patients present a unique challenge in preventing pressure ulcers because the patients are immobile and unable to perceive discomfort and pain. Operating room tables are designed for utility, not comfort. During surgery patients are positioned to accommodate the various surgical positions, and to maximise the ability to expose and manipulate the surgical site. The conventional operating room table mattress is composed of foam, and there are newer products now available. 14

27 The table mattress is normally fitted with mattress sections which correspond in size with the head, torso and foot section of the table. The foot section generally is affected because the patient s heels invariably rest in this area. Pillows and wedges can be used to assist positioning, maintaining body alignment and protecting direct contact between bony prominences. The protection of the patient can not be the responsibility of nurses alone, all members of the operating room team have a key role to play in the reduction of the incidence of pressure ulcers. The team need to be aware of their role in prevention strategies and the need to constantly review best practice based on research. 15

28 Introduction Perioperative nurses are faced with challenges when caring for their surgical patients. Because of the long periods of immobility and inability to perceive pain and discomfort from the prolonged pressure on the operating room table mattress, these patients are at risk of developing pressure ulcers. Whilst many patients in ICU environments may be immobile, nursing staff can re-position them to relieve pressure; this is unlike patients undergoing operative procedures that demand the patient remain in pre-determined positions for long periods. The intra-operative period is a time of greatest risk for the hospitalised surgical patient. Surgery is one of the few times an individual, who is not normally at risk, is placed at high risk of the development of pressure ulcers (Stewart 1998). It is only when preventative interventions, supported by evidence, are targeted to those patients at greatest risk, can the cost-effectiveness of preventative measures be realised and quality nursing care of all patients, be introduced. Nixon, McElvenny, Mason, Brown and Bond (1998) indicate that in the United Kingdom alone, the extent of intra-operative pressure ulcer development for patients within the National Health Service (NHS) is unknown, yet many hospital pressure ulcer prevention policies include strategies for operating rooms. Recommendations for the intra-operative period are limited to the provision of equipment designed for operating tables which do not impinge on the stability that is required for the patient s position and safety, or anaesthetic and surgical needs (Nixon et al 1998). There are many products available for use on the operating room table; these include foam mattresses, dry elastic polymer pads (Action Pads), displacement cell mattresses and silicone fibre overlays. In 1994 none of the product types had been subjected to any clinical evaluation by randomised controlled trial (Bridel 1993a). It appears from contemporary literature that very little has changed since that date, and it remains largely unclear to what extent these surfaces can prevent 16

29 pressure ulcers, and whether any surface is better than another (Cullum, Decks, Fletcher, Sheldon, Song 2001). The dry visco-elastic polymer pad and the displacement cell mattress were the only two that had been evaluated (Nixon, McElvenny, Mason, Brown, Bond 1998). However these tests were conduced with healthy, non-anaesthetised volunteers, and in a laboratory environment therefore the results need to be considered and interpreted with caution (Neander & Birkenfield 1991, Moore, Rithalia & Gonsakorale 1992). Pressure-relieving interventions The aim of pressure ulcer prevention strategies is to reduce the magnitude and/or duration of pressure; this includes shear and friction, between a patient and their support surface, or the interface pressure. This may be achieved by regular manual repositioning for example, two hourly turning in the ward environment or by using a special bed. Alternatively it may consist of using pressure-relieving support surfaces, such as cushions, mattress overlays, replacement mattresses or whole bed replacements. The cost of these interventions varies widely, from as little as $100 to over $30,000. However there appears to be little information on the relative cost-effectiveness of this equipment. This information is needed in order to aid in decision-making about the use of some of the items (Cullum et al. 2001). Nationally accepted evidence about the most cost-effective equipment for use in the prevention of pressure ulcer development will benefit nurses and patients by favourably modifying preventative practices, while decreasing vulnerability to litigation. The continuing threat of fault-based litigation against sub-standard practices and facilities provides an on-going safeguard of patient rights (Beyer 2000). Pressure ulcers are expensive to manage, difficult to heal, and demoralising to affected patients (Komanetsky 2000). The costs associated with this include funding to hospitals to cover the employment of staff and specific supplies used in the treatment of these wounds (Komanetsky 2000). There is also the potential for legal action to be taken against the hospital, and nursing staff 17

30 may be called upon to act as a witness to patient care practices within the organisation (Komanetsky 2000). Price, Bale, Newcombe and Harding (1999) believe that the use of high tech equipment is not always the most effective equipment for the prevention of pressure ulcer development. Maintenance of high tech, high cost systems is bound to have an impact on the growing demand for funding in health care systems. A national approach towards this problem is necessary in order to resolve the problem. Care and equipment use based on rigorous research will contribute towards better standards of care and the potential to save governments funding that could be reallocated for other patient care needs (Price et al 1999). In the ward setting there are a number of interventions that can be implemented to reduce the incidence of pressure such as changing position, massage, and of course a number of supports, from sophisticated dynamic mattresses to simple items such as pillows. However many of these interventions are unsuitable for use in the operating room and frequent turning and mattresses that constantly move are inappropriate as the patient is required to remain motionless for surgery. Any movement, however slight, may have serious ramifications as the surgeon may inadvertently damage tissues other than those identified for surgery. Once sterile drapes have been placed on the patient and sterile field is developed, they become inaccessible to the nurses. The Australian College of Operating Room Nurses recommends that any handling of the sterile drapes, once positioned on the patient for surgery, is a breach in aseptic technique in that the sterile field is contaminated and patient care compromised due to an infection risk (ACORN 2002). 18

31 Several types of operating table mattresses have been developed to reduce interface pressure. The required characteristics for these items of equipment are stability, firmness, pressure reduction and even pressure without flattening, collapsing or bottoming out. The result of the last three characteristics of the mattress not being available due to damage or wear and tear results in the patient resting on the underlying hard surface, defeating the purpose of the mattress (Hoshowsky & Schramm 1994, Schultz, Bien, Drummond, Brown & Myer 1999). Pressure-relieving cushions, beds and mattresses, called constant low pressure devices, either mould around the body shape of the patient and distribute the weight of the patient over a larger surface area or by a mechanical method varies the pressure under the patient. This in turn reduces the duration of the pressure applied, and is termed an alternating pressure device (Bliss and Thomas 1993). Constant low pressure devices either in the form of overlays, mattresses or replacement beds, can be grouped together according to the construction and manufacture of them. These items include materials such as foam, foam and air, foam and gel. There are other devices available that alternate inflation and deflation of air filled cells, these generate high to low interface pressure between the patient and the body support surface. All these devices can be used in many and varied situations and environments, ward areas, high dependency unit and long term care facilities. However the use of some of these devices in the operating room is problematic due to the need for the patient to remain in specific, and at times, unnatural positions, for several hours during their surgical procedure. The overall aim in the use of pressure reduction surfaces is to reduce the pressure lower than that of the standard hospital operating room mattress. Devices such as an overlay, placed directly on top of the mattress, and a replacement mattress, which is used in place of standard foam operating table mattress are frequently used. The most common composition of overlays is foam, gel, air or water. 19

32 Prior to the patient s surgical experience a thorough assessment by nursing staff is essential that should focus on the general condition of the patient, eg mobility, pre-existing medical conditions and risk for pressure ulcer development. This information should assist the nurse to determine appropriate patient care during surgery. Pressure ulcer development may be minimised by planning for care. Assessments will provide information to assist with the management of the patient, and the techniques used may be many and varied, dependent upon the results of the assessment. It is not that there are major differences in the care of all patients, but rather that there needs to be an emphasis and greater attention to the various aspects of care of the elderly patient (Lantz & Wyble 1987). A lack of risk assessment on patients entering the operating room environment has implications for both patient care and the nurse s responsibility and accountability. Skin assessment pre-operatively is fundamental to the early identification of skin damage and provides a baseline for the planning and evaluation of interventions. Russell (1996) asserts that even nurses who are knowledgeable about risk assessment and prevention, do not necessarily implement these skills in the delivery of care. Failure to have provided the appropriate care to reduce the incidence of pressure ulcer development may result in legal action for the hospital (Dimond 1994). Many aspects should be considered that are equally applicable to other patients, but one specific area that does require attention in some detail, is that of positioning for surgery. Positioning is a major area in which adaptations are frequently needed in order to provide individualised care. Stiff neck, arthritic joints and sore backs may require additional padding (Jackson 1989). Additional padding to compensate for the loss of subcutaneous tissue, and lifting and moving the patient rather than sliding or pulling should be considered the better option to prevent skin injury. 20

33 The Joanna Briggs Institute for Evidence Based Practice Information Sheets (BPIS) Pressure Sores Part 1 and 2, provides evidence to support changes to practice (Joanna Briggs Institute for Evidence Based Nursing 1997). The BPIS identifies clinical and cost effective nursing practice through a critical review process that promotes the use of effective nursing practice and improved patient outcomes. However they have not produced an information sheet that specifically focuses on pressure ulcers in the operating room environment. A review of the literature conducted by the researcher, revealed that although there are a number of products on the market for pressure area care, few of these are designed for use in the operating room, and those that are available have limited research to support the claims made by manufacturers. Reviews of varying types have been used in the areas of nursing and medicine to summarise and evaluate treatments and clinical practice. However, no specific guidelines exist on the best methods and strategies to be employed for the prevention of pressure ulcer development, and reviews very rarely involve an exhaustive search or a critical review of all studies (Jones & Evans 2000). It is difficult to assess the validity and comprehensiveness of the reviews conducted about support surfaces, because the nature and extent of search strategies and selection criteria, are usually not specified (Jones & Evans 2000). The quality of the studies is often not adequately assessed and, without pre-determined guidelines, the interpretation and summary of the findings is open to bias (Jones & Evans 2000). Reviews themselves are a form of research and should, therefore be conducted as rigorously and methodically in their approach as any primary research conducted (Droogan & Cullum, 1998). This critical review was undertaken to identify and summarise research relating to the most efficient and effective operating table mattress or foam, that can be used to prevent pressure ulcer development during a patient s surgical experience in the perioperative environment. 21

34 The critical review method was based on the work of the Centre for Reviews and Dissemination at the University of York (NHS Centre for Reviews and Dissemination 1996) and the Cochrane Collaboration, York (Mulrow & Oxman 1997), and The Joanna Briggs Institute. Operating room tables are designed for utility, not comfort. Ideal mattresses should be firm, stable, and reduce the distribution of pressure evenly without bottoming out, the mattress collapsing or flattening, leaving the patient on the hard, metal surface of the table. This ideal mattress is designed for the surgeons convenience, and not for patient comfort. During surgery, patients are positioned to maximise the ability to expose and manipulate the surgical site. During the surgical procedure, many parts of the body, which are not designed to bear any weight, are suddenly subjected to pressures of varying intensity for example the; heels, elbows and sacrum. Critical Review Process Objective The objective of this review was to present the best available evidence related to the most effective operating room table mattress that can be used for the prevention of pressure ulcer development, the operating room environment. Methods A review of the research literature related to pressure ulcers and surgical patients was conducted to determine the effectiveness of pressure relieving surfaces on the operating room table. The review focused on information that indicated a potential connection between the operating room table and the development of pressure ulcers. The objective of this review was to present the best available evidence relating to the use of operating table mattresses as an item of pressure reducing equipment in the operating room. The software programme developed by the Cochrane Collaboration (Rev. Man. 4.0) was used to graphically present the results from individual randomised controlled trials. 22

35 Where possible, a graphical summary of results is presented or the findings were summarised in a narrative form. Examples of initial search terms used were: Decubitus Elderly Surgical Patients Operation Perioperative Perioperative Nursing Pressure Areas Pressure Area Care Pressure Ulcers Redness / discolourisation of skin Theatre Types of Participants Studies of Adults who underwent elective surgical procedures requiring them to be positioned on operating room table mattresses, were included in the reviews. These positions include but was not limited to, prone, lithitomy, left and right lateral. Exclusion Criteria Studies that included paediatric patients. These patients are not part of the population of the organisation in which the study is conducted. Studies that included volunteers in a controlled laboratory setting because the volunteers were healthy and able to move freely and not representative of the ageing population who are surgical patients. Studies completed outside of the operating room environment. The critical review is on the effectiveness of operating room table mattresses, and their contribution to, or prevention of, pressure ulcers, therefore patients in ICU and long-term health care facilities were not considered. Studies not written in English Inclusion Criteria Any adult patient over the age of a18 years of age undergoing a surgical procedure. 23