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Pressure ulcer incidence in an acute care setting
WOUND CARE S E C T I O N EDITOR: Barbara Bates-Jensen, RN, MN, C E T N
Pr@ssur@ U o@r Inc d e n c e n an A o u b
Care Sett ng Bette Olson, MS, RN, Diane Langemo, PhD, RN, Christine Burd, PhD, RN, Darlene Hanson, MS, RN, Susan Hunter, MSN, RN, a n d Tressa Cathcart-Silberberg, MS, MA, RN, C
T h e purpose of this prospective study was to determine the incidence of pressure ulcers a n d to examine factors related to pressure ulcer development i n patients in an acute care setting. Adult m e d i c a l a n d surgical patients who were free of pressure ulcers at admission were assessed within 36 hours of admission a n d then three times per week for2 weeks or until discharge. Instruments included o demographic d a t a form, a skin assessment form, a n d the Braden Scale for Predicting Pressure Sore Risk. Most subjects h a d 46 assessments completed. The sample consisted of 149 subjects, with a pressure ulcer incidence rate of 13.4% (n = 20). Subjects who acquired pressure ulcers hod lower hemoglobin levels (t = 2.17, p = 0.03), spent more time in b e d (t = 3.90, p = 0.0001), a n d spent less time in a chair (t = 3.2, p = 0.002) than those who did not acquire pressure ulcers. A stepwise logistic regression a n a l y sis w a s used to calculate risk of pressure ulcer development. In the final model, hemoglobin level a n d hours spent in b e d continued to be predictors of pressure ulcer development (~2 = 9.306, df = 2, p = 0.0095). All 20 subjects who acquired pressure ulcers were further categorized into groups with stage I (n = 12) or stage II (n = 8) ulcers. Patients with stage I pressure ulcers were primarily receiving postsurgical care (67%), whereas patients who acquired stage II ulcers h a d m e d i c a l conditions that affected tissue pertusion, such as respiratory diseases (50%) a n d diabetes mellitus (12%). (J WOCN 1996; 23:15-22)
One million people in acute care hospitals and nursing homes have pressure ulcers2 A pressure ulcer is defined as a "localized area of tissue necrosis that tend to develop when soft tissue is compressed
between a bony prominence and an external surface for a prolonged period of time. ''1 Pressure ulcers "represent a continuum from an erythematous soft tissue lesion to an open w o u n d extending into the deep tissues. ''I Evidence of pressure ulcers dates back before recorded history, with ulcers noted in Egyptian mummies. 2 In recent years, however, there has been renewed interest in pressure ulcer prevention among health care providers. This concern is twofold: the vulnerability of the current patient population and the financial implications. Patients admitted to hospitals today are more acutely ill and include a large number of frail, elderly persons. Pressure ulcers are costly to hospitals, increasing length of hospital stay and related costs. They also have significant effects on patients, who must endure the cost, suffering, and pain associated with a pressure ulcer. The cost of treatment for one pressure ulcer in the acute care setting ranges from $2000 to $30,000,1 with an average daily inpatient cost to the facility of $80.42. 3 One analysis found that hospitals lost $215 million overall in fiscal year 1987 in the treatment of pressure ulcers. 4 Patients older than 70 years are at greater risk for development of pressure ulcers, according to a 1989 study of 278 hospitalized patientsd This finding was further supported in a 1994 prevalence study by Meehan, 6 who found that 54% of the patients who acquired a pressure ulcer were between the ages of 70 and 89 years. The risk of in-hospital death increases fourfold among elderly patients when a pressure ulcer occurs and increases six times when the ulcer does not heal. 7 Considering the number of hospital beds occupied by elderly people, it can be assumed that pressure ulcers pose a sig-
Ms. Olson is an associate professor at the University of North Dakota College of Nursing, Grand Forks, North Dakota. Dr. Langemo is a professor at the University of North Dakota. Dr. Burr is an assistant professor at the University of North Dakota. Ms. Hanson and Ms. Hunter are assistant professors at the University of North Dakota. Ms. Cafhcart-Silberberg is a doctoral candidate, University of Texas, Austin. Supported in part by Gaymar Industries, Orchard Park, New York, and the University of North Dakota College of Nursing. Reprint requests: Bette Olson, MS, RN, Associate Professor, University of North Dakota Co//ege of Nursing, P.O. Box 9025, University Station, Grand Forks, hid 58201. Copyright© 1996by the Wound, Ostorny and Continence Nurses Society. 1071-5754/96 $5.00+ 0
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nificant risk to the welfare of patients in acute care settings. Approximately 7.7% of patients confined to a bed or chair for at least 1 week in a hospital setting will acquire pressure ulcers within 3 weeks. 7 The two most critical determinants of pressure ulcer development are (1) intensity and duration of pressure and (2) tissue tolerance of the skin and its supporting structures. 8 A n y individual placed on a regimen of bed rest for an extended period is therefore at risk for skin breakdown. Patients in wheelchairs are also at great risk because of the intensity of pressure. The most common site for pressure ulcer development is the sacrum. 9 In one study by Meehan 9 in 1990, the trochanter was found to be the site of the most stage IV pressure ulcers (28%). Pressure ulcers are also frequently found on elbows, heels, and ankles. ~°' 11 Incidence refers to the number of "new cases occurring over a given time period, ''1 whereas prevalence refers to the number of "new and old cases assessed on a cross-sectional, one-time basis. ''~ Reported pressure ulcer incidences in hospitals range from 2.7 I2 to 29.5%. ~3' 14 Some estimates m a y be conservative because stage I pressure ulcers have not been consistently included in the calculation of incidence rates. Factors most recognized as placing patients at high risk for pressure ulcer development include advanced age, decreased mobility, malnutrition, moisture, and incontinence? 5' i6 Nurses have the responsibility for skin care of individual patients and for hospital-wide surveillance and prevention programs. Pressure ulcer prevention and early intervention and treatment programs are essential for all health care agencies. Not only do effective prevention programs decrease pain and suffering, they assist in the documentation of quality care while containing cost. s Pressure ulcer prevention involves the early recognition of patients at risk and includes the implementation of adequate preventive measures, including frequent and systematic head-to-toe assessments, frequent turning, placement of the patient on a pressure-reducing or pressure-relieving device, and adequate nutrition. Although current Medicare reimbursement policy contains no incentive to provide preventive care, health care agencies have found it to be a financial benefit to pre-
vent pressure ulcers among patients determined to be at high risk and then attempt to seek reimbursement from Medicare. 4 The purpose of this study was to determine the incidence of pressure ulcers on the medical-surgical units in an acute care hospital. Risk factors for pressure ulcer development were also analyzed. This study is a follow-up to a prevalence study reported by Langemo et al. I° in the same setting.
METHODS Setting The site for the study was a 260-bed acute care hospital located in a rural Midwestern state. Medical and surgical inpatients aged 18 years and older who did not have any pressure ulcers on admission were eligible.
Sample All adults aged 18 years and older who did not have any pressure ulcers at admission were invited within 36 hours after admission to participate in the study. The purpose of the study was explained to each subject or guardian, and consent was obtained in accordance with H u m a n Subjects Review Committee review and approval. The study of pressure ulcer incidence was conducted in two parts. Part I included unit A (orthopedics) and unit B (general medical and cardiovascular surgical) and was conducted b y agency staff under the direct supervision of the researcher (B. O.) over a 3-month period. Before data collection, in-service programs were conducted for all agency staff involved in the study. Part II included unit C (general and gynecologic surgical) and unit D (renal, genitourinary, otolaryngology, and oncology) and was conducted by agency staff. The same instruments and protocol were used by agency staff in consultation with the researcher (B. O.) over a 3-month period. All data were combined for purposes of analysis.
Instruments Three instruments were used for data collection for parts I and II: (1) a demographic data form, (2) a skin assessment tool, and (3) the Braden Scale for Predicting Pressure Sore Risk. The demographic data tool collected information related to
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age, sex, diagnosis, weight, height, vital signs, steroid therapy, and smoking history. These variables were selected on the basis of literature review, which indicated their importance in pressure ulcer development. The skin assessment form contained the definition of pressure ulcer stages I through IV and a diagram detailing all pressure point areas to be assessed. Each site was assessed and rated from 0 (no redness or breakdown) to 4 (stage IV pressure ulcer). Stage I pressure ulcers were defined as nonblanchable erythema of intact skin. 17 The rating system ensured that all patients received assessment and rating in a systematic and consistent manner. Data collected also included type of mattress (e.g., regular mattress, low-air loss bed, alternating pressure bed) and chair (e.g., regular chair, wheelchair, recliner) used by patients, as well as any bed and chair overlays. Mattress overlays were made of polyurethane or foam, gel, sheepskin, water, or air-filled vinyl cushions. Bowel and bladder continence data were also obtained for each patient; these variables have been noted to be related to pressure ulcer development. 1~' 1 6 The Braden Scale for Predicting Pressure Sore RiskTM is a summative rating scale composed of six mutually exclusive subscales. The subscales reflect critical determinants of pressure (mobility, activity, and sensory perception) and factors influencing the tolerance of the skin and supporting structures for pressure (skin moisture, nutritional status, and friction and shear). The m a x i m u m possible total score is 23: a rating of i (least favorable) to 3 or 4 (most favorable) is used for each subscale. A low cumulative score denotes high risk; a high score indicates low risk. Interrater reliability for the Braden Scale has previously been reported as 88% for registered nurses (r = 0.99) and 11% to 38% for licensed practical nurses and nurses aides (r = 0.83 to 0.94). 19All volunteer research assistants in this study were registered nurses, except for one licensed practical nurse. After in-service education on study protocols and use of the tool, interrater reliability for the research assistants who collected data for this study was established (r = 0.98). Predictive validity of the Braden Scale has been previously established through studies in two settings, which focused on sensitivity and specificity as the indica-
Olson et al.
The reported sensitivity of the Braden Scale in each of these two studies of acute care patients was 100%; specificities were reported at 90% and 64%. 19 The risk cutoff score for the Braden Scale was established at 16 for this study. Study participants were initially assessed within 36 hours of admission to verify that they were free of pressure ulcers and to obtain written consent. If no pressure ulcer was present, a skin assessment and a Braden Scale were completed and demographic data were collected. Those patients whose expected stay in the hospital was estimated to be less than 5 days were excluded from the study. Nursing care was given to all patients according to unit routine. t o r s . 19
Part I To prevent observer bias, the skin assessment and Braden Scales were completed separately by nurses caring for the patient and by the ET nurse acting as our research assistant. Different nurses completed skin assessments and the Braden Scale assessments. Nurses completing Braden Scales placed them in sealed envelopes and forwarded them to the researcher (B. O.). If the patient's expected stay was anticipated to be at least 5 days or longer, reassessment of skin and completion of a new Braden Scale were done three times per week for 2 weeks or until discharge. Two units were used, an orthopedic unit (unit A) and a combined general medical and cardiovascular surgical unit (unit B).
Part II Part II of the study was conducted by the agency staff to obtain the incidence rate for all medical-surgical units in our hospital before the implementation and of a prevention and early intervention pressure ulcer program. In this way, the effectiveness of the program could be documented at a later date through comparison with preimplementation statistics. Two units were utilized, the general surgical unit (unit C) and the medical-surgical unit that housed patients in the renal, otolaryngology, genitourinary, and oncology services (unit D). During this part of the study, on which we consulted, the skin assessments and Braden Scales were completed by nurses caring for the patients or by nurse research assistants. Interrater reliability was addressed through
17
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Olson et al.
T a b l e 1. C o m p a r i s o n of v a r i a b l e s b e t w e e n subjects with a n d w i t h o u t pressure ulcers (n = 149) Variable NO. of subjects Mean a g e (yr) Sex (n) Male Female Ethnic background (n) White Native American Hispanic Current or past smoking (n) Currently receiving steroids ( n) Steroid use in past month (n) Mean weight at admission (Ibs) Recent weight loss (n) Mean systolic blood pressure (ram Hg) Mean diastolic blood pressure (ram Hg) Mean pulse pressure (mm Hg) Mean Hbg at admission (mg/dl) Mean Hct at admission (%) Mean total lymphocyte count (cells/mm 3)
M e a n hours spent in bed per day M e a n hours up in chair per day
PU + 20 67
PU129 62
TOTAL 149 63
9 11
73 56
82 67
18 2 -10
122 5 2 71
140 7 2 81
1 1
12 10
13 11
151.8 7 132.6
164.9 26 133.7
163.2 33 134
72.9
76.7
76
59.8 12.6*
56.7 14.1
57.1 13.9
49.8 1421
39.5 1410
22.6t
20.3
20.6
1.5~
3.1
2.9
38 1341
PU+,Patientswith pressureulcers; PU-, patients without pressureulcers; Hgb, hemoglobin; Hct, hematocrit. *p= 0.03 on t test. i p = 0.0001 on ttest. :~p = 0.002 on ttest.
in-service education. Reassessment of the skin was done three times per week for 2 weeks, or until discharge. The Braden Scale was done once within 36 hours of admission on all subjects.
RESULTS The Statistical Package for Social Sciences (SPSS-X; SPSS, Inc., Chicago, Ill.)
was used for data analysis. The sample consisted of 149 subjects, of which 82 were male (55%) and 67 were female (45%). The mean age of the subjects was 63 years (SD 16.60), with a range of 21 to 94 years. Ethnically, the sample included 140 whites (94%), seven Native Americans (4.7%), and two Hispanics (1.3%; Table 1).
The incidence of pressure ulcers was 13.4%. Of the 20 patients with pressure ulcers, nine were male (45%)and 11 were female (55%). The incidence rate for male subjects was 11% and the rate for female subjects was 16%. These patients had a total of 28 pressure ulcers; five subjects had two pressure ulcers and one had four (Table 2). Of the subjects with pressure ulcers, eighteen were white (90%) and two were Native American (10%).
Comparison of Subjects With and Without Pressure Ulcers Subjects who acquired pressure ulcers are compared with those who did not acquire pressure ulcers in Table 1. Compared with subjects without pressure ulcers, subjects who acquired pressure ulcers were older (mean age 67 vs 62 years), had a lower body weight on admission (mean weight 152 vs 163 pounds), and had a lower lymphocyte count (mean value 1341 vs 1421 cells/mm3). None of these differences were statistically significant. There were statistically significant differences between group means of three other variables. The mean hemoglobin level for subjects who acquired pressure ulcers was 12.6 g m / d l (SD 2.1), compared with 14.0 g m / d l for subjects who did not acquire ulcers (SD 6, t=2.17, p=0.03). Subjects who acquired pressure ulcers spent significantly more time in bed than did those who remained free of ulcers (22.6 vs 20.3 hours, t=3.2, p=0.0001). Subjects who acquired pressure ulcers also spent significantly less time in chairs than did subjects who remained free of ulcers (mean 1.5 vs 3.1 hours). A stepwise logistic regression analysis (Table 2) was used to determine the risk of pressure ulcer development for 143 subjects (six subjects were excluded for incomplete data). The dependent (outcome) variable was the development of a pressure ulcer, and the independent (predictor) variables were age, hours spent in bed, hours spent in a chair, systolic and diastolic blood pressures, fecal continence, body weight, hemoglobin level, hematocrit, pulse pressure, and current or previous steroid usage. The best-fitting model for analysis was the backward stepwise conditional model. After five variables were dropped from the final equation, hemoglobin level and hours in bed continued to be predictors. The final model is portrayed in Table 3.
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Table 2. Pressure ulcer incidence by nursing unit PU+
Total no. of pressure ulcers (n = 28)
Unit
N
NO. (n = 20)
%
Unit A (orthopedics) Unit B (cardiovascular surgery and medical) Unit C (general surgical) " Unit D (oncology, nephrology, GU, ENT)
37 37 37 38
5
13.5
7
6
16.2
10
8 1
21.6 2.6
9 2
PU+, Patients with pressure ulcers; GU, genitourinary; ENT, otolaryngology.
The cardiovascular medical-surgical unit (unit B) and the surgical unit (unit C) had the highest incidences of pressure ulcers (62.2% and 21.6%, respectively). The cardiovascular unit had more stage II ulcers (n = 3), whereas those on the surgical unit had more stage I ulcers (n = 6). The oncology and renal unit (unit D) had only one patient who acquired any pressure ulcers, a stage II ulcer on each elbow. In this study, the elbows were the most frequent site for skin b r e a k d o w n (n = 11), followed by the sacral and coccyx area (n = 8). Most elbow ulcers (n = 9) were stage I, whereas most sacral ulcers (n = 5) were classified as stage II. No subjects acquired stage III or IV pressure ulcers during the observation period.
Comparative Trends Between Subjects With Stage I and Stage II Pressure Ulcers Stage I pressure ulcers do not involve a break in the skin; whereas stage II through IV ulcers do. The 20 subjects who acquired pressure ulcers were further categorized into groups with stage I ulcers (n = 12) or stage II ulcers (n = 8). Six subjects had both stage I and stage II ulcers. Demographic data and risk factors of subjects in these two groups were studied to see whether any distinct differences emerged. Subjects who acquired stage II ulcers were older; had a higher frequency of recent weight loss during the past 3 months; smoked more; had lower hemoglobin levels, hematocrits, and total lymphocyte counts; and spent more time in bed while in the hospital. The mean date of pressure' ulcer occurrence for subjects with stage II ulcers was hospitalization d a y 8.4, whereas stage I pressure ulcers occurred earlier during the hospital stay (hospitalization d a y 6). Subjects with stage I pressure ulcers were mainly receiving postsurgical care; those with stage
Table 3. B a c k w a r d stepwise logistic regression Variable Pulse
~
SE
Sig
0.0155
0.0150
0.3022
Hemoglobin
2.2090
0.1177
0,0731
Bed hours per day
0.2045
0,1066
0.0551
Z2 = 9.306, dr= 2, p = 0.0095. Sig, Significance.
II pressure ulcers had medical conditions that affected tissue perfusion, such as respiratory diseases (50%) and diabetes (12%; Table 4).
DISCUSSION The pressure ulcer incidence of 13.4% was slightly higher than the 3% to 11% reported by the National Pressure Ulcer A d v i s o r y Panel. 1 This may be reflective of the revised 1989 National Pressure Ulcer A d v i s o r y Panel definition for pressure ulcers, which includes nonblanchable erythema of intact skin. Before 1989, m a n y ulcers now classified as stage I would not have been included in this category. In addition, patients admitted to acute care facilities m a y be more acutely ill than in the past. The intense scrutiny of the subjects during the course of this study m a y also contribute to a higher incidence than that reported by the National Pressure Ulcer A d v i s o r y Panel. 1 Patients who did not have an expected stay of at least 5 days and those who died within a few days of admission were not included. This m a y have affected the pressure ulcer incidence and represents a limitation of the study. If stage I pressure ulcers had been excluded from this study, the incidence rate would have been 6%. There were 38 subjects in the subgroup on the medical-surgical unit that housed mainly patients from the oncology and nephrology services, but only one subject in this subgroup acquired any pressure
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T a b l e 4. C o m p a r i s o n of v a r i a b l e s a m o n g subjects b y stage (n = 20) Variable Subjects with pressure ulcers (n) Mean age (yr)
pressure ulcer positive
Stage I
Stage II
12
8
66
69
4 8 5 (42%) 1 (8.5%) 1 (8.5%) 149 4 (33%) 127.5 68.3 59.2 12.87 38.45 1346
4 3 6 (63%) 0 0 156 3 (38%) 140.5 79.8 60.75 12.14 36.1 1277
22.08 1.42 6
23.25 0.5 8.5
67 --15
38 50 12 13
Sex (n) Male Female Current or past smoking (n) Currently receiving steroids (n) Steroid use in past month (n) Mean weight at admission (Ibs) Recent weight loss (n) Mean systolic blood pressure (mm Hg) Mean diastolic blood pressure (mm Hg) Mean pulse pressure (mm Hg) Mean Hgb at admission (mg/dl) Mean Hct at admission (%) Mean total lymphocyte count (cells/mm 3) Mean hours spent in bed per day Mean hours up in chair per day Mean day-of occurrence Medical diagnoses (%) Surgical Respiratory Diabetes Total no. of pressure ulcers
Hgb, Hemoglobin; Hct, hematocrif.
ulcers. The low incidence rate on this unit may have been caused by the case mix of patients on the unit at the time of the study. The case mix included patients admitted for pneumonia, dehydration, depression, diabetes, organic brain syndrome, gout, and prostate surgery. Remarkably, only two of these 38 subjects had overlays applied to their beds during their hospitalization. The one subject on this unit who acquired pressure ulcers had two stage II ulcers, one on each elbow. This subject was 88 years old and had a history of diabetes mellitus, cardiovascular disease, subacute bacterial endocarditis, and cancer of the bladder. On the orthopedic unit, many patients were placed on overlays (which varied from pressure-reducing to pressure-relieving, with most being pressure-reducing) at admission. Nurses on this unit communicated, both verbally and through actions, an awareness of the risk of pressure ulcer development among or-
thopedic patients. Staff awareness of pressure ulcer risk may have been heightened by previous prevalence studies and by this study itself. The medical and cardiovascular surgical unit had the most stage II ulcers (n = 3). All of these subjects were medical patients and had a history of respiratory disease, including one with lung cancer. It can be hypothesized that these medical conditions interfere with tissue perfusion and nutrition status, creating a higher risk for pressure ulcer development. Again, overlays were not applied to the beds of these patients before pressure ulcer development. It is possible that applying overlays sooner might have prevented pressure ulcer development. Even though all pressure ulcers cannot be prevented, more consistent use of overlays could significantly reduce pressure ulcer incidence, is The increasing use of pressure-reduction mattresses as well as overlays must be systematically evaluated for efficacy in preventing or decreasing the severity of pressure ulcers, as well as for cost-effectiveness. In addition, the recommendations set forth by the Agency for Health Care Policy and Research panel for the prediction and prevention of pressure ulcers must be seriously heeded. These guidelines recommend daily skin inspection, flexible bathing schedules, moisturizing of the skin, no massage of bony prominences, proper positioning, transferring and turning techniques, and the use of pressure-reduction mattress and lubricants to reduce friction. I5
Profile of the Patient With Pressure Ulcers In this study sample, subjects with pressure ulcers had significantly lower hemoglobin values than did those without pressure ulcers. In addition, although these differences were not statistically significant, the subjects with pressure ulcers were older, smoked more, weighed less, had experienced recent weight loss, and had lower diastolic blood pressure compared with subjects who did not acquire pressure ulcers. The longer the patient spent in bed, the higher the risk for development of a pressure ulcer. Each of these risk factors has previously been observed by other investigators. 16 Hemoglobin levels were significantly lower for
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patients with pressure ulcers compared with subjects without pressure ulcers, which may be related to decreased tissue perfusion. The frequent occurrence of elbow pressure ulcers may be related to the postoperative status of the patients and to an increased use of elbows for assistance with moving in bed. More frequent use of a trapeze may be helpful, as well as a pressure-reducing mattress in place of the standard hospital mattress. It is helpful to instruct patients to avoid resting on elbows and using them to move around in bed. Prophylactic application of a hydrogel, hydrocolloid, transparent dressing, or foam elbow protector also may serve to reduce friction and pressure. The other variables were not statistically significant predictors in this study, possibly because of the small sample size.
Comparison of Subjects With Stage I and II Pressure Ulcers When comparing subjects who acquired stage I versus stage II pressure ulcers (Table 4), subjects with stage II pressure ulcers were found to be older; to have a smoking history, to have had recent weight loss; to have lower hemoglobin level, hematocrit, and total leukocyte count; and to spend more time in bed. The only statistically significant differences between the groups, however, were in smoking history and hours spent in bed. The mean age of 69 years for subjects with stage II pressure ulcers was close to the high-risk age of 70 years and older reported by Oot-Giromini et al. 5 and Meehan.6, lo The mean admission Braden Scale scores for subjects with stage I ulcers and subjects with stage II ulcers were identical at 15.9, which closely matches the cutoff score of 16 established by Bergstrom et al) 8 for acute care facilities. Patients need to be reassessed at regular intervals and when a significant change in their condition occurs, so that caregivers can intervene in a timely manner. Repeated Braden Scale scores were only obtained in part I of this incidence study, which included the orthopedic unit and the medical and cardiovascular surgical unit, and are reported elsewhere by Langemo et al? ~ The mean admission Braden Scale score for the entire sample (n = 74) was 16.88 (SD 3.45). The recommended cutoff score for these two units, determined by calculating the Braden
Scale score before development of the pressure ulcer, was 15.11 Repeated assessments would alert nurses to the fact that prolonged immobility, malnutrition, and incontinence, as well as sudden changes in the patient's condition, increase the risk for development of pressure ulcers. The agency research team chose not to obtain repeated Braden Scale scores in part II; this represents a limitation of the study.
Recommendations for Further Research Further investigation is needed regarding the specific pressure ulcer risk factors and their relationship to the incidence of pressure ulcers of stage I versus stages II through IV. For example, can it be substantiated that specific risk factors are more predictive of the development of lower versus higher stage ulcers? The ability to identify risk factors for higher stage pressure ulcer development would justify more aggressive prevention strategies, compared with those indicated for patients at risk for lower stage pressure ulcers. Researchers in each clinical setting are advised to determine their site-specific incidence rates for pressure ulcers. We recommend that incidence studies be conducted in different settings to allow comparisons among varying patient populations. Additional research questions should be studied. These include an investigation of the potential for pressurereducing mattresses or overlays to reduce the incidence of pressure ulcers. Research is needed to determine whether staff education significantly reduces the incidence of pressure ulcers, the cost-effectiveness of pressure-reducing overlays as a preventive measure, and the relationships between positioning, transferring, and turning methods and pressure ulcer incidence. The effectiveness in the prevention of pressure ulcers of elbow and heel protectors, transparent skin covers, and other protective coverings also should be studied.
CONCLUSION In this sample, both young and older subjects acquired pressure ulcers, although the group with pressure ulcers was predominantly older. Those who had an underlying disease condition, especially a condition affecting tissue perfu-
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Olson et al.
January 1996
sion (respiratory disease, cardiovascular disease, or diabetes), tended to acquire stage II pressure ulcers, whereas patients receiving postsurgical care (temporarily immobile and overall less compromised) primarily acquired stage I pressure ulcers. History of smoking and time spent in bed were significant predictors for stage II ulcers. Perhaps the stage I pressure ulcers could have been prevented with overlays, and patients with underlying disease conditions could have been placed on pressure-relieving mattresses or overlays. Special thanks to Edith Soil, BSN, RN; Pat Guthmiller, BSN, RN, CETN; Virginia Esslinger MS, RN, and the Administrative Department Directors of the Medical-Surgical Units from the United Hospital, Grand Forks; all of the nurse research assistants from United Hospital; and Katherine Maidenberg, MPA, BA, Research Analyst, University of North Dakota.
REFERENCES I. National Pressure Ulcer Advisory Panel. Pressure ulcer prevalence, cost and risk assessment: consensus development conference statement. Decubitus 1989;2(2):24-8. 2. Rowling JT. The pathological changes in mummies. Proc R Soc M e d 1961;54:409-15. 3. Alterescu V. The financial costs of inpatient pressure ulcers in an acute care facility.Decubitus 1989;2(3):14-9, 22-3. 4. Cotter D, Stefanik K. Medicare reimburse for change. Dermatol Nuts 1990;2:343-5, 5. Oot-Giromini B, Bidwell F, Heller N, et al. Pressure ulcer prevention versus treatment: comparative product cost study. Decubitus 1989;2(3):52-4.
6. Meehan M. National pressure ulcer preva-
lence survey. Adv W o u n d Care 1994;7(3):27-8, 34, 36-8. 7. Allman RM, Laprade CA, Noel LB, et al. Pressure sores a m o n g hospitalized patients. Ann Intern M e d 1986; 105:337-42. 8. Braden B, Bergstom N. A conceptual s c h e m a for the study of the etiology of pressure sores. Rehabil Nuts 1987;12(I):8-12, 16. 9. M e e h a n M. Multisite pressure ulcer prevalence survey. Decubitus 1990;3(4): 14-7. 10. L a n g e m o D, Olson B, Hanson D, Burd C, Cathcart-Silberberg T, Hunter S. Prevalence of pressure ulcers in five patient care settings. J Enterostom Ther 1990; 17:187-92. 11. L a n g e m o DK, Olson B, Hunter S, Hanson D, Burd C, Cathcart-Silberberg T. Incidence and prediction of pressure ulcers in five patient care settings. Decubitus 1991 ;4(3):25-6, 28, 30, 32, 36. 12. Gerson LW. The incidence of pressure sores in active treatment hospitals. Int J Nuts Stud 1975;12:201-4. 13. Clark M, K a d h o m HM. Pressure ulcer prevention of pressure sores in hospital and community patients. J Adv Nurs 1987;13:365-73. 14. Allman RM. Epidemiology of pressure sores in different populations. Decubitus 1989;2:30-3. 15. Agency for Health Care Policy and Research. Pressure ulcers in adults: prediction and prevention. Rockville, Maryland: US Department of Health and H u m a n Services, 1992. 16. Gosnell DA. Pressure ulcer risk assessment. Part II: analysis of risk factors. Decubitus 1989;2(3):40-3. 17. Shea JD. Pressure sores: classification and m a n a g e m e n t . Clin Orthop 1975;I 12:89-100. 18. Bergstrom N, Braden B, Laguzza A, Holman V. The Braden Scale for predicting pressure sore risk. Nurs Res 1987;36:205-10. 19. Bergstrom N, Demuth P J, Braden BJ. A clinical trial of the Braden Scale for predicting pressure sore risk.Nurs Clin North A m 1987;22:417-28.
CAET SCHOLARSHIPS AVAILABLE
Scholarships are offered by the Canadian Association of Enterostomal Therapy for Canadians wishing to become ET nurses. Information and application forms may be obtained at the following address: Kathy Mutch, RN, ET Scholarship Chairperson Queen Elizabeth Hospital RO. Box 6600 Charlottetown, Prince Edward Island Canada CIA 8T5 902-566-6111
Pr@ssur@ U o@r Inc d e n c e n an A o u b
Care Sett ng Bette Olson, MS, RN, Diane Langemo, PhD, RN, Christine Burd, PhD, RN, Darlene Hanson, MS, RN, Susan Hunter, MSN, RN, a n d Tressa Cathcart-Silberberg, MS, MA, RN, C
T h e purpose of this prospective study was to determine the incidence of pressure ulcers a n d to examine factors related to pressure ulcer development i n patients in an acute care setting. Adult m e d i c a l a n d surgical patients who were free of pressure ulcers at admission were assessed within 36 hours of admission a n d then three times per week for2 weeks or until discharge. Instruments included o demographic d a t a form, a skin assessment form, a n d the Braden Scale for Predicting Pressure Sore Risk. Most subjects h a d 46 assessments completed. The sample consisted of 149 subjects, with a pressure ulcer incidence rate of 13.4% (n = 20). Subjects who acquired pressure ulcers hod lower hemoglobin levels (t = 2.17, p = 0.03), spent more time in b e d (t = 3.90, p = 0.0001), a n d spent less time in a chair (t = 3.2, p = 0.002) than those who did not acquire pressure ulcers. A stepwise logistic regression a n a l y sis w a s used to calculate risk of pressure ulcer development. In the final model, hemoglobin level a n d hours spent in b e d continued to be predictors of pressure ulcer development (~2 = 9.306, df = 2, p = 0.0095). All 20 subjects who acquired pressure ulcers were further categorized into groups with stage I (n = 12) or stage II (n = 8) ulcers. Patients with stage I pressure ulcers were primarily receiving postsurgical care (67%), whereas patients who acquired stage II ulcers h a d m e d i c a l conditions that affected tissue pertusion, such as respiratory diseases (50%) a n d diabetes mellitus (12%). (J WOCN 1996; 23:15-22)
One million people in acute care hospitals and nursing homes have pressure ulcers2 A pressure ulcer is defined as a "localized area of tissue necrosis that tend to develop when soft tissue is compressed
between a bony prominence and an external surface for a prolonged period of time. ''1 Pressure ulcers "represent a continuum from an erythematous soft tissue lesion to an open w o u n d extending into the deep tissues. ''I Evidence of pressure ulcers dates back before recorded history, with ulcers noted in Egyptian mummies. 2 In recent years, however, there has been renewed interest in pressure ulcer prevention among health care providers. This concern is twofold: the vulnerability of the current patient population and the financial implications. Patients admitted to hospitals today are more acutely ill and include a large number of frail, elderly persons. Pressure ulcers are costly to hospitals, increasing length of hospital stay and related costs. They also have significant effects on patients, who must endure the cost, suffering, and pain associated with a pressure ulcer. The cost of treatment for one pressure ulcer in the acute care setting ranges from $2000 to $30,000,1 with an average daily inpatient cost to the facility of $80.42. 3 One analysis found that hospitals lost $215 million overall in fiscal year 1987 in the treatment of pressure ulcers. 4 Patients older than 70 years are at greater risk for development of pressure ulcers, according to a 1989 study of 278 hospitalized patientsd This finding was further supported in a 1994 prevalence study by Meehan, 6 who found that 54% of the patients who acquired a pressure ulcer were between the ages of 70 and 89 years. The risk of in-hospital death increases fourfold among elderly patients when a pressure ulcer occurs and increases six times when the ulcer does not heal. 7 Considering the number of hospital beds occupied by elderly people, it can be assumed that pressure ulcers pose a sig-
Ms. Olson is an associate professor at the University of North Dakota College of Nursing, Grand Forks, North Dakota. Dr. Langemo is a professor at the University of North Dakota. Dr. Burr is an assistant professor at the University of North Dakota. Ms. Hanson and Ms. Hunter are assistant professors at the University of North Dakota. Ms. Cafhcart-Silberberg is a doctoral candidate, University of Texas, Austin. Supported in part by Gaymar Industries, Orchard Park, New York, and the University of North Dakota College of Nursing. Reprint requests: Bette Olson, MS, RN, Associate Professor, University of North Dakota Co//ege of Nursing, P.O. Box 9025, University Station, Grand Forks, hid 58201. Copyright© 1996by the Wound, Ostorny and Continence Nurses Society. 1071-5754/96 $5.00+ 0
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nificant risk to the welfare of patients in acute care settings. Approximately 7.7% of patients confined to a bed or chair for at least 1 week in a hospital setting will acquire pressure ulcers within 3 weeks. 7 The two most critical determinants of pressure ulcer development are (1) intensity and duration of pressure and (2) tissue tolerance of the skin and its supporting structures. 8 A n y individual placed on a regimen of bed rest for an extended period is therefore at risk for skin breakdown. Patients in wheelchairs are also at great risk because of the intensity of pressure. The most common site for pressure ulcer development is the sacrum. 9 In one study by Meehan 9 in 1990, the trochanter was found to be the site of the most stage IV pressure ulcers (28%). Pressure ulcers are also frequently found on elbows, heels, and ankles. ~°' 11 Incidence refers to the number of "new cases occurring over a given time period, ''1 whereas prevalence refers to the number of "new and old cases assessed on a cross-sectional, one-time basis. ''~ Reported pressure ulcer incidences in hospitals range from 2.7 I2 to 29.5%. ~3' 14 Some estimates m a y be conservative because stage I pressure ulcers have not been consistently included in the calculation of incidence rates. Factors most recognized as placing patients at high risk for pressure ulcer development include advanced age, decreased mobility, malnutrition, moisture, and incontinence? 5' i6 Nurses have the responsibility for skin care of individual patients and for hospital-wide surveillance and prevention programs. Pressure ulcer prevention and early intervention and treatment programs are essential for all health care agencies. Not only do effective prevention programs decrease pain and suffering, they assist in the documentation of quality care while containing cost. s Pressure ulcer prevention involves the early recognition of patients at risk and includes the implementation of adequate preventive measures, including frequent and systematic head-to-toe assessments, frequent turning, placement of the patient on a pressure-reducing or pressure-relieving device, and adequate nutrition. Although current Medicare reimbursement policy contains no incentive to provide preventive care, health care agencies have found it to be a financial benefit to pre-
vent pressure ulcers among patients determined to be at high risk and then attempt to seek reimbursement from Medicare. 4 The purpose of this study was to determine the incidence of pressure ulcers on the medical-surgical units in an acute care hospital. Risk factors for pressure ulcer development were also analyzed. This study is a follow-up to a prevalence study reported by Langemo et al. I° in the same setting.
METHODS Setting The site for the study was a 260-bed acute care hospital located in a rural Midwestern state. Medical and surgical inpatients aged 18 years and older who did not have any pressure ulcers on admission were eligible.
Sample All adults aged 18 years and older who did not have any pressure ulcers at admission were invited within 36 hours after admission to participate in the study. The purpose of the study was explained to each subject or guardian, and consent was obtained in accordance with H u m a n Subjects Review Committee review and approval. The study of pressure ulcer incidence was conducted in two parts. Part I included unit A (orthopedics) and unit B (general medical and cardiovascular surgical) and was conducted b y agency staff under the direct supervision of the researcher (B. O.) over a 3-month period. Before data collection, in-service programs were conducted for all agency staff involved in the study. Part II included unit C (general and gynecologic surgical) and unit D (renal, genitourinary, otolaryngology, and oncology) and was conducted by agency staff. The same instruments and protocol were used by agency staff in consultation with the researcher (B. O.) over a 3-month period. All data were combined for purposes of analysis.
Instruments Three instruments were used for data collection for parts I and II: (1) a demographic data form, (2) a skin assessment tool, and (3) the Braden Scale for Predicting Pressure Sore Risk. The demographic data tool collected information related to
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age, sex, diagnosis, weight, height, vital signs, steroid therapy, and smoking history. These variables were selected on the basis of literature review, which indicated their importance in pressure ulcer development. The skin assessment form contained the definition of pressure ulcer stages I through IV and a diagram detailing all pressure point areas to be assessed. Each site was assessed and rated from 0 (no redness or breakdown) to 4 (stage IV pressure ulcer). Stage I pressure ulcers were defined as nonblanchable erythema of intact skin. 17 The rating system ensured that all patients received assessment and rating in a systematic and consistent manner. Data collected also included type of mattress (e.g., regular mattress, low-air loss bed, alternating pressure bed) and chair (e.g., regular chair, wheelchair, recliner) used by patients, as well as any bed and chair overlays. Mattress overlays were made of polyurethane or foam, gel, sheepskin, water, or air-filled vinyl cushions. Bowel and bladder continence data were also obtained for each patient; these variables have been noted to be related to pressure ulcer development. 1~' 1 6 The Braden Scale for Predicting Pressure Sore RiskTM is a summative rating scale composed of six mutually exclusive subscales. The subscales reflect critical determinants of pressure (mobility, activity, and sensory perception) and factors influencing the tolerance of the skin and supporting structures for pressure (skin moisture, nutritional status, and friction and shear). The m a x i m u m possible total score is 23: a rating of i (least favorable) to 3 or 4 (most favorable) is used for each subscale. A low cumulative score denotes high risk; a high score indicates low risk. Interrater reliability for the Braden Scale has previously been reported as 88% for registered nurses (r = 0.99) and 11% to 38% for licensed practical nurses and nurses aides (r = 0.83 to 0.94). 19All volunteer research assistants in this study were registered nurses, except for one licensed practical nurse. After in-service education on study protocols and use of the tool, interrater reliability for the research assistants who collected data for this study was established (r = 0.98). Predictive validity of the Braden Scale has been previously established through studies in two settings, which focused on sensitivity and specificity as the indica-
Olson et al.
The reported sensitivity of the Braden Scale in each of these two studies of acute care patients was 100%; specificities were reported at 90% and 64%. 19 The risk cutoff score for the Braden Scale was established at 16 for this study. Study participants were initially assessed within 36 hours of admission to verify that they were free of pressure ulcers and to obtain written consent. If no pressure ulcer was present, a skin assessment and a Braden Scale were completed and demographic data were collected. Those patients whose expected stay in the hospital was estimated to be less than 5 days were excluded from the study. Nursing care was given to all patients according to unit routine. t o r s . 19
Part I To prevent observer bias, the skin assessment and Braden Scales were completed separately by nurses caring for the patient and by the ET nurse acting as our research assistant. Different nurses completed skin assessments and the Braden Scale assessments. Nurses completing Braden Scales placed them in sealed envelopes and forwarded them to the researcher (B. O.). If the patient's expected stay was anticipated to be at least 5 days or longer, reassessment of skin and completion of a new Braden Scale were done three times per week for 2 weeks or until discharge. Two units were used, an orthopedic unit (unit A) and a combined general medical and cardiovascular surgical unit (unit B).
Part II Part II of the study was conducted by the agency staff to obtain the incidence rate for all medical-surgical units in our hospital before the implementation and of a prevention and early intervention pressure ulcer program. In this way, the effectiveness of the program could be documented at a later date through comparison with preimplementation statistics. Two units were utilized, the general surgical unit (unit C) and the medical-surgical unit that housed patients in the renal, otolaryngology, genitourinary, and oncology services (unit D). During this part of the study, on which we consulted, the skin assessments and Braden Scales were completed by nurses caring for the patients or by nurse research assistants. Interrater reliability was addressed through
17
18
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Olson et al.
T a b l e 1. C o m p a r i s o n of v a r i a b l e s b e t w e e n subjects with a n d w i t h o u t pressure ulcers (n = 149) Variable NO. of subjects Mean a g e (yr) Sex (n) Male Female Ethnic background (n) White Native American Hispanic Current or past smoking (n) Currently receiving steroids ( n) Steroid use in past month (n) Mean weight at admission (Ibs) Recent weight loss (n) Mean systolic blood pressure (ram Hg) Mean diastolic blood pressure (ram Hg) Mean pulse pressure (mm Hg) Mean Hbg at admission (mg/dl) Mean Hct at admission (%) Mean total lymphocyte count (cells/mm 3)
M e a n hours spent in bed per day M e a n hours up in chair per day
PU + 20 67
PU129 62
TOTAL 149 63
9 11
73 56
82 67
18 2 -10
122 5 2 71
140 7 2 81
1 1
12 10
13 11
151.8 7 132.6
164.9 26 133.7
163.2 33 134
72.9
76.7
76
59.8 12.6*
56.7 14.1
57.1 13.9
49.8 1421
39.5 1410
22.6t
20.3
20.6
1.5~
3.1
2.9
38 1341
PU+,Patientswith pressureulcers; PU-, patients without pressureulcers; Hgb, hemoglobin; Hct, hematocrit. *p= 0.03 on t test. i p = 0.0001 on ttest. :~p = 0.002 on ttest.
in-service education. Reassessment of the skin was done three times per week for 2 weeks, or until discharge. The Braden Scale was done once within 36 hours of admission on all subjects.
RESULTS The Statistical Package for Social Sciences (SPSS-X; SPSS, Inc., Chicago, Ill.)
was used for data analysis. The sample consisted of 149 subjects, of which 82 were male (55%) and 67 were female (45%). The mean age of the subjects was 63 years (SD 16.60), with a range of 21 to 94 years. Ethnically, the sample included 140 whites (94%), seven Native Americans (4.7%), and two Hispanics (1.3%; Table 1).
The incidence of pressure ulcers was 13.4%. Of the 20 patients with pressure ulcers, nine were male (45%)and 11 were female (55%). The incidence rate for male subjects was 11% and the rate for female subjects was 16%. These patients had a total of 28 pressure ulcers; five subjects had two pressure ulcers and one had four (Table 2). Of the subjects with pressure ulcers, eighteen were white (90%) and two were Native American (10%).
Comparison of Subjects With and Without Pressure Ulcers Subjects who acquired pressure ulcers are compared with those who did not acquire pressure ulcers in Table 1. Compared with subjects without pressure ulcers, subjects who acquired pressure ulcers were older (mean age 67 vs 62 years), had a lower body weight on admission (mean weight 152 vs 163 pounds), and had a lower lymphocyte count (mean value 1341 vs 1421 cells/mm3). None of these differences were statistically significant. There were statistically significant differences between group means of three other variables. The mean hemoglobin level for subjects who acquired pressure ulcers was 12.6 g m / d l (SD 2.1), compared with 14.0 g m / d l for subjects who did not acquire ulcers (SD 6, t=2.17, p=0.03). Subjects who acquired pressure ulcers spent significantly more time in bed than did those who remained free of ulcers (22.6 vs 20.3 hours, t=3.2, p=0.0001). Subjects who acquired pressure ulcers also spent significantly less time in chairs than did subjects who remained free of ulcers (mean 1.5 vs 3.1 hours). A stepwise logistic regression analysis (Table 2) was used to determine the risk of pressure ulcer development for 143 subjects (six subjects were excluded for incomplete data). The dependent (outcome) variable was the development of a pressure ulcer, and the independent (predictor) variables were age, hours spent in bed, hours spent in a chair, systolic and diastolic blood pressures, fecal continence, body weight, hemoglobin level, hematocrit, pulse pressure, and current or previous steroid usage. The best-fitting model for analysis was the backward stepwise conditional model. After five variables were dropped from the final equation, hemoglobin level and hours in bed continued to be predictors. The final model is portrayed in Table 3.
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Table 2. Pressure ulcer incidence by nursing unit PU+
Total no. of pressure ulcers (n = 28)
Unit
N
NO. (n = 20)
%
Unit A (orthopedics) Unit B (cardiovascular surgery and medical) Unit C (general surgical) " Unit D (oncology, nephrology, GU, ENT)
37 37 37 38
5
13.5
7
6
16.2
10
8 1
21.6 2.6
9 2
PU+, Patients with pressure ulcers; GU, genitourinary; ENT, otolaryngology.
The cardiovascular medical-surgical unit (unit B) and the surgical unit (unit C) had the highest incidences of pressure ulcers (62.2% and 21.6%, respectively). The cardiovascular unit had more stage II ulcers (n = 3), whereas those on the surgical unit had more stage I ulcers (n = 6). The oncology and renal unit (unit D) had only one patient who acquired any pressure ulcers, a stage II ulcer on each elbow. In this study, the elbows were the most frequent site for skin b r e a k d o w n (n = 11), followed by the sacral and coccyx area (n = 8). Most elbow ulcers (n = 9) were stage I, whereas most sacral ulcers (n = 5) were classified as stage II. No subjects acquired stage III or IV pressure ulcers during the observation period.
Comparative Trends Between Subjects With Stage I and Stage II Pressure Ulcers Stage I pressure ulcers do not involve a break in the skin; whereas stage II through IV ulcers do. The 20 subjects who acquired pressure ulcers were further categorized into groups with stage I ulcers (n = 12) or stage II ulcers (n = 8). Six subjects had both stage I and stage II ulcers. Demographic data and risk factors of subjects in these two groups were studied to see whether any distinct differences emerged. Subjects who acquired stage II ulcers were older; had a higher frequency of recent weight loss during the past 3 months; smoked more; had lower hemoglobin levels, hematocrits, and total lymphocyte counts; and spent more time in bed while in the hospital. The mean date of pressure' ulcer occurrence for subjects with stage II ulcers was hospitalization d a y 8.4, whereas stage I pressure ulcers occurred earlier during the hospital stay (hospitalization d a y 6). Subjects with stage I pressure ulcers were mainly receiving postsurgical care; those with stage
Table 3. B a c k w a r d stepwise logistic regression Variable Pulse
~
SE
Sig
0.0155
0.0150
0.3022
Hemoglobin
2.2090
0.1177
0,0731
Bed hours per day
0.2045
0,1066
0.0551
Z2 = 9.306, dr= 2, p = 0.0095. Sig, Significance.
II pressure ulcers had medical conditions that affected tissue perfusion, such as respiratory diseases (50%) and diabetes (12%; Table 4).
DISCUSSION The pressure ulcer incidence of 13.4% was slightly higher than the 3% to 11% reported by the National Pressure Ulcer A d v i s o r y Panel. 1 This may be reflective of the revised 1989 National Pressure Ulcer A d v i s o r y Panel definition for pressure ulcers, which includes nonblanchable erythema of intact skin. Before 1989, m a n y ulcers now classified as stage I would not have been included in this category. In addition, patients admitted to acute care facilities m a y be more acutely ill than in the past. The intense scrutiny of the subjects during the course of this study m a y also contribute to a higher incidence than that reported by the National Pressure Ulcer A d v i s o r y Panel. 1 Patients who did not have an expected stay of at least 5 days and those who died within a few days of admission were not included. This m a y have affected the pressure ulcer incidence and represents a limitation of the study. If stage I pressure ulcers had been excluded from this study, the incidence rate would have been 6%. There were 38 subjects in the subgroup on the medical-surgical unit that housed mainly patients from the oncology and nephrology services, but only one subject in this subgroup acquired any pressure
19
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Olson et al.
T a b l e 4. C o m p a r i s o n of v a r i a b l e s a m o n g subjects b y stage (n = 20) Variable Subjects with pressure ulcers (n) Mean age (yr)
pressure ulcer positive
Stage I
Stage II
12
8
66
69
4 8 5 (42%) 1 (8.5%) 1 (8.5%) 149 4 (33%) 127.5 68.3 59.2 12.87 38.45 1346
4 3 6 (63%) 0 0 156 3 (38%) 140.5 79.8 60.75 12.14 36.1 1277
22.08 1.42 6
23.25 0.5 8.5
67 --15
38 50 12 13
Sex (n) Male Female Current or past smoking (n) Currently receiving steroids (n) Steroid use in past month (n) Mean weight at admission (Ibs) Recent weight loss (n) Mean systolic blood pressure (mm Hg) Mean diastolic blood pressure (mm Hg) Mean pulse pressure (mm Hg) Mean Hgb at admission (mg/dl) Mean Hct at admission (%) Mean total lymphocyte count (cells/mm 3) Mean hours spent in bed per day Mean hours up in chair per day Mean day-of occurrence Medical diagnoses (%) Surgical Respiratory Diabetes Total no. of pressure ulcers
Hgb, Hemoglobin; Hct, hematocrif.
ulcers. The low incidence rate on this unit may have been caused by the case mix of patients on the unit at the time of the study. The case mix included patients admitted for pneumonia, dehydration, depression, diabetes, organic brain syndrome, gout, and prostate surgery. Remarkably, only two of these 38 subjects had overlays applied to their beds during their hospitalization. The one subject on this unit who acquired pressure ulcers had two stage II ulcers, one on each elbow. This subject was 88 years old and had a history of diabetes mellitus, cardiovascular disease, subacute bacterial endocarditis, and cancer of the bladder. On the orthopedic unit, many patients were placed on overlays (which varied from pressure-reducing to pressure-relieving, with most being pressure-reducing) at admission. Nurses on this unit communicated, both verbally and through actions, an awareness of the risk of pressure ulcer development among or-
thopedic patients. Staff awareness of pressure ulcer risk may have been heightened by previous prevalence studies and by this study itself. The medical and cardiovascular surgical unit had the most stage II ulcers (n = 3). All of these subjects were medical patients and had a history of respiratory disease, including one with lung cancer. It can be hypothesized that these medical conditions interfere with tissue perfusion and nutrition status, creating a higher risk for pressure ulcer development. Again, overlays were not applied to the beds of these patients before pressure ulcer development. It is possible that applying overlays sooner might have prevented pressure ulcer development. Even though all pressure ulcers cannot be prevented, more consistent use of overlays could significantly reduce pressure ulcer incidence, is The increasing use of pressure-reduction mattresses as well as overlays must be systematically evaluated for efficacy in preventing or decreasing the severity of pressure ulcers, as well as for cost-effectiveness. In addition, the recommendations set forth by the Agency for Health Care Policy and Research panel for the prediction and prevention of pressure ulcers must be seriously heeded. These guidelines recommend daily skin inspection, flexible bathing schedules, moisturizing of the skin, no massage of bony prominences, proper positioning, transferring and turning techniques, and the use of pressure-reduction mattress and lubricants to reduce friction. I5
Profile of the Patient With Pressure Ulcers In this study sample, subjects with pressure ulcers had significantly lower hemoglobin values than did those without pressure ulcers. In addition, although these differences were not statistically significant, the subjects with pressure ulcers were older, smoked more, weighed less, had experienced recent weight loss, and had lower diastolic blood pressure compared with subjects who did not acquire pressure ulcers. The longer the patient spent in bed, the higher the risk for development of a pressure ulcer. Each of these risk factors has previously been observed by other investigators. 16 Hemoglobin levels were significantly lower for
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Olson et al. 21
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patients with pressure ulcers compared with subjects without pressure ulcers, which may be related to decreased tissue perfusion. The frequent occurrence of elbow pressure ulcers may be related to the postoperative status of the patients and to an increased use of elbows for assistance with moving in bed. More frequent use of a trapeze may be helpful, as well as a pressure-reducing mattress in place of the standard hospital mattress. It is helpful to instruct patients to avoid resting on elbows and using them to move around in bed. Prophylactic application of a hydrogel, hydrocolloid, transparent dressing, or foam elbow protector also may serve to reduce friction and pressure. The other variables were not statistically significant predictors in this study, possibly because of the small sample size.
Comparison of Subjects With Stage I and II Pressure Ulcers When comparing subjects who acquired stage I versus stage II pressure ulcers (Table 4), subjects with stage II pressure ulcers were found to be older; to have a smoking history, to have had recent weight loss; to have lower hemoglobin level, hematocrit, and total leukocyte count; and to spend more time in bed. The only statistically significant differences between the groups, however, were in smoking history and hours spent in bed. The mean age of 69 years for subjects with stage II pressure ulcers was close to the high-risk age of 70 years and older reported by Oot-Giromini et al. 5 and Meehan.6, lo The mean admission Braden Scale scores for subjects with stage I ulcers and subjects with stage II ulcers were identical at 15.9, which closely matches the cutoff score of 16 established by Bergstrom et al) 8 for acute care facilities. Patients need to be reassessed at regular intervals and when a significant change in their condition occurs, so that caregivers can intervene in a timely manner. Repeated Braden Scale scores were only obtained in part I of this incidence study, which included the orthopedic unit and the medical and cardiovascular surgical unit, and are reported elsewhere by Langemo et al? ~ The mean admission Braden Scale score for the entire sample (n = 74) was 16.88 (SD 3.45). The recommended cutoff score for these two units, determined by calculating the Braden
Scale score before development of the pressure ulcer, was 15.11 Repeated assessments would alert nurses to the fact that prolonged immobility, malnutrition, and incontinence, as well as sudden changes in the patient's condition, increase the risk for development of pressure ulcers. The agency research team chose not to obtain repeated Braden Scale scores in part II; this represents a limitation of the study.
Recommendations for Further Research Further investigation is needed regarding the specific pressure ulcer risk factors and their relationship to the incidence of pressure ulcers of stage I versus stages II through IV. For example, can it be substantiated that specific risk factors are more predictive of the development of lower versus higher stage ulcers? The ability to identify risk factors for higher stage pressure ulcer development would justify more aggressive prevention strategies, compared with those indicated for patients at risk for lower stage pressure ulcers. Researchers in each clinical setting are advised to determine their site-specific incidence rates for pressure ulcers. We recommend that incidence studies be conducted in different settings to allow comparisons among varying patient populations. Additional research questions should be studied. These include an investigation of the potential for pressurereducing mattresses or overlays to reduce the incidence of pressure ulcers. Research is needed to determine whether staff education significantly reduces the incidence of pressure ulcers, the cost-effectiveness of pressure-reducing overlays as a preventive measure, and the relationships between positioning, transferring, and turning methods and pressure ulcer incidence. The effectiveness in the prevention of pressure ulcers of elbow and heel protectors, transparent skin covers, and other protective coverings also should be studied.
CONCLUSION In this sample, both young and older subjects acquired pressure ulcers, although the group with pressure ulcers was predominantly older. Those who had an underlying disease condition, especially a condition affecting tissue perfu-
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Olson et al.
January 1996
sion (respiratory disease, cardiovascular disease, or diabetes), tended to acquire stage II pressure ulcers, whereas patients receiving postsurgical care (temporarily immobile and overall less compromised) primarily acquired stage I pressure ulcers. History of smoking and time spent in bed were significant predictors for stage II ulcers. Perhaps the stage I pressure ulcers could have been prevented with overlays, and patients with underlying disease conditions could have been placed on pressure-relieving mattresses or overlays. Special thanks to Edith Soil, BSN, RN; Pat Guthmiller, BSN, RN, CETN; Virginia Esslinger MS, RN, and the Administrative Department Directors of the Medical-Surgical Units from the United Hospital, Grand Forks; all of the nurse research assistants from United Hospital; and Katherine Maidenberg, MPA, BA, Research Analyst, University of North Dakota.
REFERENCES I. National Pressure Ulcer Advisory Panel. Pressure ulcer prevalence, cost and risk assessment: consensus development conference statement. Decubitus 1989;2(2):24-8. 2. Rowling JT. The pathological changes in mummies. Proc R Soc M e d 1961;54:409-15. 3. Alterescu V. The financial costs of inpatient pressure ulcers in an acute care facility.Decubitus 1989;2(3):14-9, 22-3. 4. Cotter D, Stefanik K. Medicare reimburse for change. Dermatol Nuts 1990;2:343-5, 5. Oot-Giromini B, Bidwell F, Heller N, et al. Pressure ulcer prevention versus treatment: comparative product cost study. Decubitus 1989;2(3):52-4.
6. Meehan M. National pressure ulcer preva-
lence survey. Adv W o u n d Care 1994;7(3):27-8, 34, 36-8. 7. Allman RM, Laprade CA, Noel LB, et al. Pressure sores a m o n g hospitalized patients. Ann Intern M e d 1986; 105:337-42. 8. Braden B, Bergstom N. A conceptual s c h e m a for the study of the etiology of pressure sores. Rehabil Nuts 1987;12(I):8-12, 16. 9. M e e h a n M. Multisite pressure ulcer prevalence survey. Decubitus 1990;3(4): 14-7. 10. L a n g e m o D, Olson B, Hanson D, Burd C, Cathcart-Silberberg T, Hunter S. Prevalence of pressure ulcers in five patient care settings. J Enterostom Ther 1990; 17:187-92. 11. L a n g e m o DK, Olson B, Hunter S, Hanson D, Burd C, Cathcart-Silberberg T. Incidence and prediction of pressure ulcers in five patient care settings. Decubitus 1991 ;4(3):25-6, 28, 30, 32, 36. 12. Gerson LW. The incidence of pressure sores in active treatment hospitals. Int J Nuts Stud 1975;12:201-4. 13. Clark M, K a d h o m HM. Pressure ulcer prevention of pressure sores in hospital and community patients. J Adv Nurs 1987;13:365-73. 14. Allman RM. Epidemiology of pressure sores in different populations. Decubitus 1989;2:30-3. 15. Agency for Health Care Policy and Research. Pressure ulcers in adults: prediction and prevention. Rockville, Maryland: US Department of Health and H u m a n Services, 1992. 16. Gosnell DA. Pressure ulcer risk assessment. Part II: analysis of risk factors. Decubitus 1989;2(3):40-3. 17. Shea JD. Pressure sores: classification and m a n a g e m e n t . Clin Orthop 1975;I 12:89-100. 18. Bergstrom N, Braden B, Laguzza A, Holman V. The Braden Scale for predicting pressure sore risk. Nurs Res 1987;36:205-10. 19. Bergstrom N, Demuth P J, Braden BJ. A clinical trial of the Braden Scale for predicting pressure sore risk.Nurs Clin North A m 1987;22:417-28.
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