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Reviews and Abstracts
Journal of Tissue Viability 2000 Vol 10 No 2
69
Reviews and Abstracts Clinical study unit 10: Introducing pressure ulcer care. 'How do you do.' Pendleton S, Jones V. London: Healthcare Productions Ltd, 1999. This educational resource consists of a workbook with accompanying video. The premise is simple: after reading the EPUAP guidelines on pressure ulcer prevention, the student is invited to identify which aspects of practice illustrated in the video comply and which do not comply with the guidelines. For example a patient may be provided with an anti-pressure ulcer device (compliant) but may also have his heels rubbed with talcum (non-compliant). Three scenarios, involving a patient being repositioned in bed, moving from bed to chair and an examination of pressure areas are depicted. The student is further asked to identify risk factors associated with the patient's condition. The introduction contains short explanations of the terms pressure, shear and friction. The workbook contains activity boxes which direct the student to other relevant materials and cover such areas as intended learning outcomes, relevance to practice and guided reflection on the learning process. The general presentation and quality of this offering are excellent and entice the student to get involved in the process. The use of the EPUAP guidelines as a framework is commendable, as whatever ones' personal reservations about the detail, it is likely to be beneficial for all clinicians to have a common language and starting point for pressure ulcer prevention. It is also good to see equal emphasis being placed on younger disabled patients who are so often forgotten, thus helping to dispel the myth that pressure sores are exclusively a geriatric issue. My main reservation is that while together the workbook and video give a clear idea of what is good practice and what is not, if the video is seen on its own it might be interpreted as consisting of examples of good practice, which of course it is not. The other major failing in my view is that the student is given limited information about the patients' conditions. Thus any assessments of risk can only be extremely superficial- for example the patient might be incontinent because they have an incontinence sheet in the bed! They are overweight or underweight -none of it very relevant unless the patient is actually susceptible to pressure ulcers. Whether they Received 8 March 2000
are or not and if so, why, is only glanced upon if at all. It would have been best, perhaps, to have left this aspect to another unit which deals with the whole issue in a more meaningful way and puts the factors discussed into context. Another less than satisfying aspect is the way the usual received wisdom on chair sitting is repeated as if it were fact. The workbook recommends a chair of appropriate height (for which there is theoretical support only) and the use of a pressure relieving device (for which there is no real evidence) but makes no mention of limitation on time spent in the chair, the only intervention which has some clinical controlled evidence of benefit in its support. Overall, however, the unit is a good way of introducing the EPUAP guidelines in a practical and entertaining way, which makes the lessons likely to be remembered. A variety of risk situations was covered not just patients lying in bed. I liked particularly the way poor practice was highlighted in areas other than pressure ulcer prevention. Leaving drinks out of patients' reach is a particular bugbear of mine! In summary, a valuable addition to any educational library, but must be used under supervision to ensure that the video is always used in conjunction with the workbook, and that the student is able to make the distinction between good practice and deliberately staged bad practice. I am looking forward to further titles in this series. KS Gebhardt Clinical Nurse Specialist- Pressure Sore Prevention StGeorge's Healthcare NHS Trust, London
Core body temperature, skin temperature, and interface pressure. Relationship to skin integrity in nursing home residents Knox DM. Advances in Wound Care 1999; 12(5): 246-252 Over several years, Knox and her colleagues have investigated the effects of different turning schedules upon a range of outcome measures in an attempt to clarify the optimum interval between repositioning. The current © Tissue Viability Society
70
Journal of Tissue Viability 2000 Vol10 No 2
study from this group, based in the United States, focuses upon the effect of different turning intervals upon skin and core body temperature and upon measured interface pressures. Secondary outcome measures included skin colour changes at the end of each period of immobility. While such information may be important in refining the frequency of repositioning, the study as reported disappoints. Twenty-six elderly residents of a nursing home were recruited. These subjects ranged in age from 60 to 91 years (mean 76.71, standard deviation 10.23) and were predominantly Caucasian (16/26; 61/5%) females (17/26; 65.4%). The paper reports several inclusion and exclusion criteria, however there is a discrepancy (perhaps typographic) in their description. It is unclear whether eligible subjects were bedfast and had established sores as the paper gives such factors as both inclusion and exclusion criteria within separate sections. Eligible subjects rested upon a standard plastic-coated mattress, however 10 also used a variety of overlays to distribute the effects of pressure. The effects of the use of overlays upon the outcome measures collected are not reported. Subjects were then repositioned at hourly, 1.5 h or 2 h intervals with measurements made of body and skin temperature along with the interface pressures exerted at the sacrum and both greater trochanters. However not all subjects were exposed to all turning interventions. For example 'some participants spent 2 h on the sacrum, while other participants spent only 1 h on the sacrum, but 2 h on one of the trochanters'. The inability to control the exposure of subjects to the different turning intervals largely precludes meaningful interpretation of the data presented by Knox. The description of the subjects could have been strengthened through the inclusion of a table giving age, sex, ethnicity and body type for each subject. Body type was subjectively assessed by the ease of identifying the greater trochanters; in 'thin' subjects these prominences were easy to find. Sixteen of the subjects were classed as being thin, the numbers of 'medium' and 'heavy' subjects were not presented. It would appear that core body temperature decreased
during immobility, but this decrease was not universal for in 17 core temperature readings (of the 77 performed) increased during (unspecified) periods of immobility. Skin surface temperature was weakly and inversely correlated with core body temperature. The temperature at the sacrum was reported to be higher, albeit non-significantly, than the temperature at either greater trochanter. If the data had been presented as the change in temperature per hour of immobility, then the information gathered by Knox may have been easier to interpret. It is interesting to note that skin temperature increased, at all anatomical sites considered, during the period of immobility. Interface pressure (measured at
unspecified points over the sacrum and greater trochanters) showed wide diversity between subjects. For example, the mean average sacral interface pressure at the beginning of each period of immobility was reported to be 28.34 mmHg with a standard deviation of 12.43 mmHg. Such wide variability between subjects recorded at a large flat surface such as the sacrum may have reflected errors in the measurement of interface pressure. Regardless of the source of the variability (measurement error or real variation between subjects) the width of the standard deviations precludes all of the comparisons of pressure, anatomical site and time from reaching statistical significance. Skin colour changes were commonly observed following immobility although the presentation of the data is confusing. The tables suggest that 77 observations of skin colour were made, but the data appears to report skin colour changes by patient (n=26). Fourteen subjects showed skin colour changes after being immobile for 1 h (anatomical position unreported) while 13 showed similar changes after 2 h immobility. It would appear that there was no increase in the frequency of reported skin colour changes as the duration of immobility increased. The sacrum and both greater trochanters appeared to be equally susceptible to colour changes after immobility (duration undefined). Twelve subjects showed colour changes at the sacrum while 14 and 11 showed such changes at the right and left greater trochanters respectively. All skin colour changes were reported to have resolved twenty minutes after the repositioning of the subject, suggesting that these changes did not herald the early signs of pressure damage. Knox describes in detail the limitations of her study, touching upon the small sample size, the inability to control for ethnic differences and the effects of illness. The subjectivity of the definitions of body build and skin colour changes used during the study were also discussed. Essentially this study was fundamentally flawed by the inability to control subjects' exposure to the turning regimes. Given the variability of subjects' exposure, the presentation of the data would have been enhanced if the temperature and pressure changes had been reported as 'per hour of immobility'. While the need and optimum frequency for patient repositioning remain important issues to be resolved, this paper does not advance our understanding but does highlight the difficulties faced by researchers when attempting to introduce 'control' in any human activity! Michael Clark Research Fellow Wound Healing Research Unit Cardiff
69
Reviews and Abstracts Clinical study unit 10: Introducing pressure ulcer care. 'How do you do.' Pendleton S, Jones V. London: Healthcare Productions Ltd, 1999. This educational resource consists of a workbook with accompanying video. The premise is simple: after reading the EPUAP guidelines on pressure ulcer prevention, the student is invited to identify which aspects of practice illustrated in the video comply and which do not comply with the guidelines. For example a patient may be provided with an anti-pressure ulcer device (compliant) but may also have his heels rubbed with talcum (non-compliant). Three scenarios, involving a patient being repositioned in bed, moving from bed to chair and an examination of pressure areas are depicted. The student is further asked to identify risk factors associated with the patient's condition. The introduction contains short explanations of the terms pressure, shear and friction. The workbook contains activity boxes which direct the student to other relevant materials and cover such areas as intended learning outcomes, relevance to practice and guided reflection on the learning process. The general presentation and quality of this offering are excellent and entice the student to get involved in the process. The use of the EPUAP guidelines as a framework is commendable, as whatever ones' personal reservations about the detail, it is likely to be beneficial for all clinicians to have a common language and starting point for pressure ulcer prevention. It is also good to see equal emphasis being placed on younger disabled patients who are so often forgotten, thus helping to dispel the myth that pressure sores are exclusively a geriatric issue. My main reservation is that while together the workbook and video give a clear idea of what is good practice and what is not, if the video is seen on its own it might be interpreted as consisting of examples of good practice, which of course it is not. The other major failing in my view is that the student is given limited information about the patients' conditions. Thus any assessments of risk can only be extremely superficial- for example the patient might be incontinent because they have an incontinence sheet in the bed! They are overweight or underweight -none of it very relevant unless the patient is actually susceptible to pressure ulcers. Whether they Received 8 March 2000
are or not and if so, why, is only glanced upon if at all. It would have been best, perhaps, to have left this aspect to another unit which deals with the whole issue in a more meaningful way and puts the factors discussed into context. Another less than satisfying aspect is the way the usual received wisdom on chair sitting is repeated as if it were fact. The workbook recommends a chair of appropriate height (for which there is theoretical support only) and the use of a pressure relieving device (for which there is no real evidence) but makes no mention of limitation on time spent in the chair, the only intervention which has some clinical controlled evidence of benefit in its support. Overall, however, the unit is a good way of introducing the EPUAP guidelines in a practical and entertaining way, which makes the lessons likely to be remembered. A variety of risk situations was covered not just patients lying in bed. I liked particularly the way poor practice was highlighted in areas other than pressure ulcer prevention. Leaving drinks out of patients' reach is a particular bugbear of mine! In summary, a valuable addition to any educational library, but must be used under supervision to ensure that the video is always used in conjunction with the workbook, and that the student is able to make the distinction between good practice and deliberately staged bad practice. I am looking forward to further titles in this series. KS Gebhardt Clinical Nurse Specialist- Pressure Sore Prevention StGeorge's Healthcare NHS Trust, London
Core body temperature, skin temperature, and interface pressure. Relationship to skin integrity in nursing home residents Knox DM. Advances in Wound Care 1999; 12(5): 246-252 Over several years, Knox and her colleagues have investigated the effects of different turning schedules upon a range of outcome measures in an attempt to clarify the optimum interval between repositioning. The current © Tissue Viability Society
70
Journal of Tissue Viability 2000 Vol10 No 2
study from this group, based in the United States, focuses upon the effect of different turning intervals upon skin and core body temperature and upon measured interface pressures. Secondary outcome measures included skin colour changes at the end of each period of immobility. While such information may be important in refining the frequency of repositioning, the study as reported disappoints. Twenty-six elderly residents of a nursing home were recruited. These subjects ranged in age from 60 to 91 years (mean 76.71, standard deviation 10.23) and were predominantly Caucasian (16/26; 61/5%) females (17/26; 65.4%). The paper reports several inclusion and exclusion criteria, however there is a discrepancy (perhaps typographic) in their description. It is unclear whether eligible subjects were bedfast and had established sores as the paper gives such factors as both inclusion and exclusion criteria within separate sections. Eligible subjects rested upon a standard plastic-coated mattress, however 10 also used a variety of overlays to distribute the effects of pressure. The effects of the use of overlays upon the outcome measures collected are not reported. Subjects were then repositioned at hourly, 1.5 h or 2 h intervals with measurements made of body and skin temperature along with the interface pressures exerted at the sacrum and both greater trochanters. However not all subjects were exposed to all turning interventions. For example 'some participants spent 2 h on the sacrum, while other participants spent only 1 h on the sacrum, but 2 h on one of the trochanters'. The inability to control the exposure of subjects to the different turning intervals largely precludes meaningful interpretation of the data presented by Knox. The description of the subjects could have been strengthened through the inclusion of a table giving age, sex, ethnicity and body type for each subject. Body type was subjectively assessed by the ease of identifying the greater trochanters; in 'thin' subjects these prominences were easy to find. Sixteen of the subjects were classed as being thin, the numbers of 'medium' and 'heavy' subjects were not presented. It would appear that core body temperature decreased
during immobility, but this decrease was not universal for in 17 core temperature readings (of the 77 performed) increased during (unspecified) periods of immobility. Skin surface temperature was weakly and inversely correlated with core body temperature. The temperature at the sacrum was reported to be higher, albeit non-significantly, than the temperature at either greater trochanter. If the data had been presented as the change in temperature per hour of immobility, then the information gathered by Knox may have been easier to interpret. It is interesting to note that skin temperature increased, at all anatomical sites considered, during the period of immobility. Interface pressure (measured at
unspecified points over the sacrum and greater trochanters) showed wide diversity between subjects. For example, the mean average sacral interface pressure at the beginning of each period of immobility was reported to be 28.34 mmHg with a standard deviation of 12.43 mmHg. Such wide variability between subjects recorded at a large flat surface such as the sacrum may have reflected errors in the measurement of interface pressure. Regardless of the source of the variability (measurement error or real variation between subjects) the width of the standard deviations precludes all of the comparisons of pressure, anatomical site and time from reaching statistical significance. Skin colour changes were commonly observed following immobility although the presentation of the data is confusing. The tables suggest that 77 observations of skin colour were made, but the data appears to report skin colour changes by patient (n=26). Fourteen subjects showed skin colour changes after being immobile for 1 h (anatomical position unreported) while 13 showed similar changes after 2 h immobility. It would appear that there was no increase in the frequency of reported skin colour changes as the duration of immobility increased. The sacrum and both greater trochanters appeared to be equally susceptible to colour changes after immobility (duration undefined). Twelve subjects showed colour changes at the sacrum while 14 and 11 showed such changes at the right and left greater trochanters respectively. All skin colour changes were reported to have resolved twenty minutes after the repositioning of the subject, suggesting that these changes did not herald the early signs of pressure damage. Knox describes in detail the limitations of her study, touching upon the small sample size, the inability to control for ethnic differences and the effects of illness. The subjectivity of the definitions of body build and skin colour changes used during the study were also discussed. Essentially this study was fundamentally flawed by the inability to control subjects' exposure to the turning regimes. Given the variability of subjects' exposure, the presentation of the data would have been enhanced if the temperature and pressure changes had been reported as 'per hour of immobility'. While the need and optimum frequency for patient repositioning remain important issues to be resolved, this paper does not advance our understanding but does highlight the difficulties faced by researchers when attempting to introduce 'control' in any human activity! Michael Clark Research Fellow Wound Healing Research Unit Cardiff