predictors of pressure ulcers in adult critical care patients

8/10/2019 Predictors of pressure ulcers in adult critical care patients

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By Jill Cox, RN, PhD, APN, CWOCN

Background Pressure ulcers are one of the most underrated

conditions in critically ill patients. Despite the introduction of

clinical practice guidelines and advances in medical technol-

ogy, the prevalence of pressure ulcers in hospitalized patients

continues to escalate. Currently, consensus is lacking on themost important risk factors for pressure ulcers in critically ill

patients, and no risk assessment scale exclusively for pres-

sure ulcers in these patients is available.

Objective To determine which risk factors are most predictive

of pressure ulcers in adult critical care patients. Risk factors

investigated included total score on the Braden Scale, mobility,

activity, sensory perception, moisture, friction/shear, nutrition,

age, blood pressure, length of stay in the intensive care unit,

score on the Acute Physiology and Chronic Health Evaluation

II, vasopressor administration, and comorbid conditions.

Methods A retrospective, correlational design was used to

examine 347 patients admitted to a medical-surgical intensive

care unit from October 2008 through May 2009.Results According to direct logistic regression analyses, age,

length of stay, mobility, friction/shear, norepinephrine infusion,

and cardiovascular disease explained a major part of the vari-

ance in pressure ulcers.

Conclusion Current risk assessment scales for development

of pressure ulcers may not include risk factors common in

critically ill adults. Development of a risk assessment model

for pressure ulcers in these patients is warranted and could

be the foundation for development of a risk assessment tool.

(American Journal of Critical Care. 2011;20:364-375)

PREDICTORS OFPRESSURE ULCERS IN

ADULTCRITICALCAREPATIENTS

C E 1.0 Hour

Notice to CE enrollees:A closed-book, multiple-choice examinationfollowing this article tests your understanding ofthe following objectives:

1. Identify the stages of pressure ulcers as definedby the National Pressure Ulcer Advisory Panel.

2. Describe the components of the Braden Scalefor assessing risk for pressure ulcers.

3. Discuss potential factors not included in theBraden Scale that can be predictors for pres-

sure ulcers in critical care populations.

To read this article and take the CE test online,visit www.ajcconline.org and click CE Articlesin This Issue. No CE test fee for AACN members.

364 J AMERICAN JOURNAL OF CRITICAL CARE, September 2011, Volume 20, No. 5 www.ajcconline.org

2011 American Association of Critical-Care Nursesdoi: http://dx.doi.org/10.4037/ajcc2011934

Pressure Ulcer Management

This article is supplemented by an AJCCPatient CarePage on page 376.

by guest on January 17, 2015ajcc.aacnjournals.orgDownloaded from
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In 2006, the Centers for Medicare and Medicaid

Services6 declared that hospital-acquired stage III or

stage IV pressure ulcers are adverse patient safety

events, or never events, that could reasonably beprevented by implementing evidence-based preven-

tion guidelines. As a result, beginning in 2008, reim-

bursement limitations were enacted for acute care

hospitals for care associated with stage III or stage

IV pressure ulcers not documented as present when

a patient was admitted.7This change has sparked a

renewed urgency and awareness related to preventing

pressure ulcers. Although the implementation of

comprehensive prevention programs can reduce the

prevalence of hospital-acquired pressure ulcers,8,9

pressure ulcers do develop in hospitalized patients,

despite quality care and best practice. Furthermore,the risk for pressure ulcers may be greater for ICU

patients than for other patients.10-12

The first step in preventing pressure ulcers is deter-

mining what constitutes appropriate risk. Many risk

factors have been identified empirically; however, con-

sensus on the most important risk factors is lacking.

Review of Relevant LiteratureThe lack of a risk assessment scale exclusively for

determining the risk for pressure ulcers is an imped-

iment to accurately determining risk in critical care

patients.3,13 In the United States, the Braden Scale14 is

the most widely used risk assessment tool in most

care settings, including the ICU, and current clinical

practice guidelines15-17 recommend its use. With the

Braden Scale, derived from the conceptual framework

of Braden and Bergstrom,18 6 subscales are used to

measure risk for pressure ulcers: sensory perception,

activity, mobility, nutrition, moisture, and friction/

shear. Potential scores range from 6 to 23; lowerscores indicate greater risk. Scores of 15 to 18 indi-

cate risk or mild risk; scores of 13 to 14, moderate

risk; scores of 10 to 12, high risk; and scores of 9 or

less, very high risk.19 Stratification of risk for pressure

ulcers can be useful clinically for determining and

implementing the appropriate level of prevention.20

Although evidence4,21-23 supports the total score

on the Braden Scale as a predictor of pressure ulcers

in critical care patients, investigation of the contribu-

tions of the subscale scores has been limited, and the

findings have been inconclusive. Although the sub-

scales of sensory perception,22,24

moisture,21,24

mobil-ity,21 and friction/shear24 have been found to be

significant predictors of pressure ulcer

development in ICU patients, the activ-

ity and nutrition subscales have not.

Other factors not included in

the Braden Scale may also increase a

patients level of risk for pressure ulcers

and thus be important determinants

in adult critical care patients. Empirical

evidence suggests that the following

factors can be predictive of pressure

ulcers in critical care patients:

advanced age1,4,21,25,26; low arteriolar pressure27-29; pro-

longed ICU stay1,21,26,30; severity of illness as indicated

by scores on the Acute Physiology and Chronic

Health Evaluation (APACHE) II1,31; comorbid condi-

tions, including diabetes mellitus, sepsis, and vascular

disease21,25,27; and iatrogenic factors, such as the use

of vasopressor agents.1,25,27Although research has

indicated that many of these factors are significantly

related to the development of pressure ulcers in ICU

patients, the findings were not consistent in all of

the studies in which these relationships were tested.

D

evelopment of pressure ulcers is complex and multifactorial. In critical care

patients, pressure ulcers are an additional comorbid threat in patients who are

already physiologically compromised. In fact, pressure ulcers are one of the

most underrated medical problems in critical care patients.1 Despite advances

in medical technology and the use of formalized prevention programs based

on clinical practice guidelines, the prevalence of pressure ulcers during hospitalization contin-ues to increase. In 2008, Russo et al2 of the Health Care Cost and Utilization Project reported

an 80% increase in the occurrence of pressure ulcers from 1993 to 2006 in hospitalized adult

patients and estimated that total associated health care costs were $11 billion. Among all hos-

pitalized patients, prevalence rates of acquired pressure ulcers are the highest in patients in the

intensive care unit (ICU), from 14% to 42%.3-5

About the AuthorJill Cox is an advanced practice nurse and a wound,ostomy, continence nurse at Englewood Hospital andMedical Center, Englewood, New Jersey.

Corresponding author: Jill Cox, RN, PhD, APN, CWOCN,Englewood Hospital and Medical Center, 350 Engle St,Englewood NJ, 07631 (e-mail: [email protected]).

www.ajcconline.org J AMERICAN JOURNAL OF CRITICAL CARE, September 2011, Volume 20, No. 5 365

Pressure ulcersare one of themost underratedmedical problemsin critical carepatients.



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medical-surgical ICU (MSICU) in Englewood Hos-

pital and Medical Center, a suburban Magnet teach-

ing hospital in Englewood, New Jersey.

Sample

All adult patients admitted to the MSICU from

October 2008 through May 2009 who met theinclusion criteria were included in this convenience

sample. Patients were included if they were 18 years

or older and had an MSICU stay of 24 hours or greater.

Patients were excluded if they had an MSICU stay

of less than 24 hours or had a pressure ulcer at the

time of admission to the MSICU. A power analysis

was conducted for regression analysis to determine

an appropriate sample size.32 In order to achieve a

power of 80%, a minimum sample size of 163 was

needed for a moderate effect size, a significance level

of = .05, and 22 predictor variables.

Data Collection

Data were abstracted from the hospitals exist-

ing computerized documentation systems and

included the following study variables: pressure

ulcer (recorded as present or absent at discharge

from the MSICU); score on Braden Scale at the

time of admission to the MSICU; scores on

Braden subscales at admission to the unit; age;

arteriolar pressure (defined as the total number

of hours in the first 48 hours that the patient had

mean arterial pressure


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Data Analysis

SPSS, version 16.0 for Windows, software (SPSS

Inc, Chicago Illinois) was used for data analysis.

Descriptive statistics included frequency distribu-

tions for study variables and demographic data. The

Pearson product moment correlation was used for

correlational analyses of the study variables. Directlogistic regression was used to create the best model

for predicting the development of pressure ulcers in

ICU patients. For comparison of study variables

between patients with and without pressure ulcers,

t tests and 2 analysis were used.

ResultsDescription of the Sample

Of the 579 patients admitted to the MSICU

during the study period, 347 met the inclusion cri-

teria and were included in the final sample. The

patients were 20 to 97 years old (mean, 69; SD, 17).The top 3 admitting diagnoses were respiratory fail-

ure or distress (20.7%), sepsis or septic shock (17.3%),

and neurological problems (15%). Demographic

characteristics of the sample are summarized in

Table 2.

Descriptive Statistics of the Study Variables

Descriptive statistics of the study variables are

summarized in Table 3. Among the 347 patients in

the sample, a pressure ulcer developed in 65 (18.7%).

Of these ulcers, most (35%) were stage II, and the

sacrum was the most common anatomical location

(58%). Mean time until development of a pressure

ulcer was 133.61 hours (median 90.0; range, 5-573;

SD, 120.13). The distribution of pressure ulcers by

stage and hours to development is summarized in

Table 4.

Mean Braden Scale scores were 14.28 (SD, 2.68;

range, 6-23) for the entire patient sample, 12.73

(SD, 2.65) for patients in whom pressure ulcers

developed, and 14.63 (SD, 2.65) for patients who

remained ulcer-free. Of the 65 patients in whom a

pressure ulcer developed, 28% (n= 18) were classi-

fied as at risk, 28% (n = 18) as at moderate risk,

35% (n= 23) as at high risk, and 9% (n= 6) as atvery high risk. Predictive validity of the Braden Scale

was measured by using sensitivity and specificity

values in addition to negative and positive predic-

tive values36 (Table 5). At a cut-off score of 18, the

sensitivity was 100%, specificity was 7%, positive

predictive value was 20%, and negative predictive

value was 100%. According to the scores on the

Braden Scale, 94% of the sample was predicted to

be at risk for pressure ulcers; the actual occurrence

rate was 18.7%.

Logistic Regression Analyses

Independent variables significantly associated

with the dependent variable development of a pres-

sure ulcer were included in direct logistic regression

(Table 6). The following risk factors were significant

predictors of pressure ulcers: mobility (B = -0.823;

P= .04; odds ratio [OR]= 0.439; 95% confidence

interval [CI], 0.21-0.95), age (B=0.033;

P= .03; OR= 1.033; 95% CI, 1.003-

1.064), length of ICU admission

(B= 0.008; P< .001; OR = 1.008; 95%

CI, 1.005-1.011), and cardiovascular

disease (B=1.082; P= .007; OR= 2.952;

95% CI, 1.3-6.4; Table 7).

In order to better understand the

risk factors that lead to actual breaks

in skin integrity, a second direct logisticregression was done for a subsample of

the population (n= 327) that excluded all patients in

whom a stage I pressure ulcer developed. The fol-

lowing risk factors were significantly predictive of

the development of a stage II or greater pressure

ulcer: friction/shear (B= 1.743; P= .01; OR = 5.715;

95% CI, 1.423-22.950), length of ICU stay (B=.008;

P< .001; OR=1.008; 95% CI, 1.004-1.012), norepi-

nephrine administration (B= .017; P=.04; OR=1.017;

95% CI, 1.001-1.033), and cardiovascular disease


A pressureulcer developedin 18.7% of thesample; mostwere stage II

sacral ulcers.

Table 2

Demographic characteristicsof the study sample (n = 347)

Characteristic Valuea

a Values are number (%) unless otherwise indicated. Because of rounding, not allpercentages total 100.

Age, mean (SD), range, y

SexMaleFemale

RaceWhiteBlack/African AmericanAsian/Pacific IslanderHispanic

Other

Intensive care unit admitting diagnosisRespiratory arrest/distressSepsis/septic shockNeuromedical problem

General medical problemGastrointestinal bleedingNeurosurgical problemGastrointestinal surgical problemVascular surgical problemOther surgical problemCardiac conditionCardiac arrest

69 (17.0), 20-97

171 (49.3)176 (50.7)

255 (73.5)48 (13.8)26 (7.5)17 (4.9)

1 (0.3)

72 (20.7)60 (17.3)52 (15.0)

44 (12.7)24 (6.9)24 (6.9)23 (6.6)17 (4.9)13 (3.7)12 (3.5)

6 (1.7)



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Braden Scale led to successful identification of

patients at risk, subsequently mobilizing clinicians

to implement appropriate strategies to prevent pres-

sure ulcers and thus averting the occurrence of the

ulcers, or potentially unnecessary strategies to pre-vent pressure ulcers were implemented, resulting in

excessive health care costs and potential inefficient

use of caregivers time.

Of the 6 Braden subscales, only mobility and

friction/shear were significant predictors of pressure

ulcers. Mobility is defined on the Braden Scale as

the ability of a patient to turn and control body

movement.18 Compared with patients who were

ulcer-free, patients in whom pressure ulcers devel-

oped had significant lower scores on the mobility

subscale, with a mean subscale score of 2.0, defined

(B = 1.218; P= .02; OR = 3.380; 95% CI, 1.223-

9.347; Table 7).

Discussion

In this study sample, a Braden Scale score of 18was not predictive of the development of a pressure

ulcer. In fact, 75% (n= 261) of the patients were

classified as at risk for pressure ulcers (Braden Scale

score 18) but remained ulcer-free (see Figure).

When the Braden Scale was used, the risk for pres-

sure ulcers was overpredicted, as indicated by the

low specificity and low positive predictive value.

Because of the overprediction, drawing any impor-

tant conclusions about the capability of the scale in

predicting development of pressure ulcers in the

patients in the study is difficult. Either use of the


Table 3

Descriptive statistics of study variables and comparison of patientswith acquired pressure ulcers and patients without pressure ulcers

Total Braden scoreSensory perception subscale

Moisture subscaleActivity subscaleMobility subscaleNutrition subscaleFriction/shear subscale

Age, y

Arteriolar pressure, hMean arterial pressure


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as very limited mobility. Turning and repositioning

an immobile patient is a basic tenet of nursing care

and is recommended in all current practice guide-

lines as a strategy to prevent pressure ulcers. Although

evidence for the optimal frequency for reposition-

ing immobile patients is lacking,37 the guidelines16,17

indicate that regular repositioning is vital. Someevidence38 also supports the use of low air loss mat-

tresses for pressure redistribution in ICU patients.

The use of low air loss mattresses and regular turn-

ing and repositioning of immobile patients may be

2 essential strategies for preventing pressure ulcers

in critical care patients. The effect of progressive

mobility programs on reduction of pressure ulcers

in ICU patients is an area ripe for empirical study.

Development of a stage II or greater pressure

ulcer was almost 6 times more likely in patients with

higher exposure to friction/shear than in patients

with low exposure. Previous studies in critical carepatients have yielded inconclusive evidence for this

subscale. Although Jiricka et al24 found a significance

difference in the mean Braden friction/shear sub-

scale scores between patients in whom pressure ulcers

developed and patients who remained ulcer-free,

other investigators21,22 found no relationship between

the subscale and development of pressure ulcers in

critical care patients. In a recent study39 in a surgical

trauma ICU, 41 patients at high risk for pressure

ulcers received an application of a silicone-bordered,

nonadherent foam dressing to the sacral area to

minimize the forces of friction, shear, and moisture.

Application of this topical dressing significantly

reduced the occurrence of pressure ulcers to zero.

The study is being replicated to validate the findings.

Immobile, critically ill patients are totally

dependent on caregivers for both repositioning and

transfers, increasing the risk for exposure to the

forces of friction/shear and subsequent develop-

ment of pressure ulcers. Advocates of safe patient

handling procedures recommend the use of glide

sheets and patient transfer devices to reduce the

deleterious effects of friction/shear on the skin and

simultaneously protect staff from musculoskeletal

injuries.40Additional factors such as prolonged headelevation in critically ill, intubated patients to pre-

vent ventilator-associated pneumonia or in enterally

fed patients to prevent aspiration also increase the

risk for exposure to friction/shear. Continued research

into the effects of prolonged head elevation on skin

integrity is warranted to better understand the

sequelae of shear forces and to develop interventions

to counteract these forces.

In my study, patients in whom pressure ulcers

developed had lower mean scores on the Braden

sensory perception subscale than did patients who

remained ulcer-free. However, this subscale was not

a significant predictor. Diminished levels of sensory

perception experienced by all patients in the sample

may have rendered this risk factor nonsignificant


Table 4

Analysis of patients with pressure ulcers

Characteristic

No. of pressure ulcers by stage and hours to detection

No. (%)a

Pressure ulcer

Pressure ulcer stageIIIIII

IVDeep tissue injury

Unstageable

Pressure ulcer locationSacrumButtocksHeels

Other

Hours to pressure ulcer detection1-8

49-7273-144145

Hours to

detection

1-48

49-72

73-144

145

Stage I

8

2

3

7

Stage II

7

2

6

8

Stage III

0

0

1

0

Stage IV

0

0

0

1

Deeptissue

injury

5

2

3

5

Unstage-

able

1

1

2

1

Total

21

7

15

22

65 (18.7)

20 (31)23 (35)1 (2)

1 (2)15 (23)

5 (7)

38 (58)22 (34)3 (5)

2 (3)

21 (32)7 (11)

15 (23)

22 (34)

a Because of rounding, not all percentages total 100.

Criterion Description

Sensitivity

Specificity

Predictive value ofa positive test

Predictive value of

a negative test

What percentage of patients who actually had apressure ulcer develop were classified as at risk?

What percentage of patients who remained free of apressure ulcer were accurately classified as not at risk?

How accurate is the risk assessment scale as aprospective predictor of which patients will have apressure ulcer develop?

How accurate is the risk assessment scale as a

prospective predictor of which patients will nothave a pressure ulcer develop?

a Based on data from Bolton.36

Table 5

Predictive validity criteria of a pressureulcer risk assessment scalea



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when analyzed with other risk factors. In 2 previous

studies22,24 in critical care patients, however, scores

on the Braden sensory perception subscale were

predictive of pressure ulcers. Current pressure ulcer

guidelines17 recommend that practitioners consider

the impact of the score on the Braden sensory per-

ception subscale when determining a patient's riskfor pressure ulcers.

In my sample, the activity subscale was not

related to development of pressure ulcers, a finding

consistent with the results of previous studies21,22,24

in critical care patients in which the Braden activity

subscale was used. Because most patients in the

MSICU were bed bound, the patients in my sample

had little variation in activity levels.

A possible explanation for the finding that the

score on the Braden moisture subscale was not pre-

dictive of pressure ulcers in my study is the frequent

use of indwelling devices that minimize skin expo-sure to moisture from 2 primary sources: urine

(indwelling urinary catheters) and liquid stool

(fecal containment devices). In 2 previous studies21,24

in ICU patients, scores on the Braden moisture sub-

scale were predictive of pressure ulcers, and in another

study,1 fecal incontinence was a significant risk fac-

tor for pressure ulcers. Bowel management systems,

also called fecal containment devices, were intro-

duced to the clinical market in 2004, after the

aforementioned studies were published. In a study

by Benoit and Watts,41 use of these devices in com-

bination with strategies to prevent pressure ulcers

decreased the prevalence of pressure ulcers for

patients exposed to high levels of moisture from

liquid stool incontinence.

Although scores on the Braden nutrition subscale

were related to the development of pressure ulcers

in my study, the scores were not a significant pre-

dictor, consistent with the findings of previous

studies21,22,24 in ICU patients. The score on this sub-

scale is a measure of the usual food intake of a

patient, and most critically ill patients may have

difficulty articulating a diet history or be unable to

do so, especially in the initial days of an ICU admis-

sion, diminishing the value of the subscale in thesepatients. In a previous study26 in ICU patients, how-

ever, nutrition, measured as the number of days

without nutrition, was a significant predictor of the

development of pressure ulcers. Additionally, the

results of measurements of many biological mark-

ers of nutrition, such as body weight, serum levels

of albumin, and, in some instances, serum levels of

prealbumin, may be erroneous because of fluid shifts

that occur in critical illness, thus creating greater

challenges in determining appropriate objective


Independent variable Independent variable rr

Total Braden scoreMobilityActivitySensory perceptionMoistureFriction/shear

NutritionAgeMean arterial

pressure


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nutritional markers. Currently, there is a lack of

consensus among researchers and clinicians regard-

ing the best metric of nutritional status.42

In my study, risk factors not included in the

Braden Scale, that is, age, length of ICU stay, norepi-

nephrine administration, and cardiovascular disease,

were all significant predictors. The mean age of patientsin whom pressure ulcers developed was 73 years,

whereas the mean age in patients who remained

ulcer-free was 67 years. Strong empirical evidence

supports the relationship between advanced age

and development of pressure ulcers in critical care

patients, and perhaps this risk factor should be

given stronger consideration for inclusion in a risk

assessment scale.1,4,21,25,26

In my study, development of pressure ulcers

was more likely in patients with longer ICU stays

than in patients with shorter stays. This result is

consistent with the findings of previous studies.

1,21,26

In my study, the mean MSICU stay was 281 hours

(11.7 days) for patients in whom a pressure ulcer

developed and 81 hours (3.3 days) for patients who

remained ulcer-free.

The most vulnerable time for development of

pressure ulcers during the MSICU stay was the first

week; 66% of the sample had development of a

pressure ulcer in the first 6 days of their MSICU

stay, a finding consistent with the results of other

studies22,23,43 in critical care patients. On the basis of

this finding, the first week of a patients ICU stay

should be a period of hypervigilance to assess the

risk for pressure ulcers, and strategies to prevent

such ulcers should be aggressively implemented. Par-

adoxically, the first week of an ICU stay may also be

the most likely period in which a patient experi-

ences the greatest physiological instability, requiring

nurses and other members of the health care team

to manage multiple life-saving technologies while

simultaneously preventing pressure ulcers. During

this time, communication among all members of

the health care team of the potential for pressure

ulcers is crucial. Moreover, a multidisciplinary forum

can underscore the premise that prevention of pres-

sure ulcers is the responsibility of all members ofthe health care team, not just nurses.

In my study, norepinephrine was the only vaso-

pressor that was a significant predictor for pressure

ulcers, a finding consistent with the results of previ-

ous studies1,27 in ICU patients. Of note, 32 of the 65

patients (49%) in my study who had a pressure ulcer

develop received norepinephrine. Moreover, the mean

number of hours of norepinephrine infusions in

patients who had stage II or higher pressure ulcers

was significantly higher (55 hours) than in patients

who remained ulcer-free (4 hours). Evidence to

support norepinephrine as a predictor of pressureulcers in critical care patients is increasing.1,27

Cardiovascular disease was the only comorbid

condition in my study that was a significant predic-

tor of pressure ulcers. In my sample, 57% of patients

in whom pressure ulcers developed had cardiovas-

cular disease. Although cardiovascular disease has

been associated with the development of pressure

ulcers in non-ICU patients and in cardiac surgery

patients,44-47 this comorbid condition has not been

studied extensively as a risk factor in

general ICU patients. Further research

is needed to elucidate the importance

of this unmodifiable risk factor in the

development of pressure ulcers in

general critical care patients.

In my study, patients in whom a

pressure ulcer developed had signifi-

cantly lower mean diastolic blood

pressures, lower mean arterial pres-

sure, and lower mean systolic blood

pressures than did patients who

remained free of pressure ulcers.

However, none of these variables was a significant

predictor. In 3 previous studies27,28,43 in ICU patients,

no significant relationships were found between anymeasure of blood pressure and development of

pressure ulcers. In another study,29 diastolic blood

pressure was lower in critical care patients in whom

pressure ulcers developed; however, this relationship

was not statistically significant. The finding that

none of the blood pressure variables was a predictor

of pressure ulcers in my study and in other studies

is noteworthy and may be due to the frequent mon-

itoring of blood pressure in critical care patients,

resulting in quicker implementation of interventions


Figure Score on the Braden Scale and occurrence of pressureulcers (blue bars, present; red bars, absent).

No.ofpatients

Score on Braden Scale

019-23 15-18 13-14 10-12 6-9

75

100

125

50

25

The first week

of stay in theintensive care unitshould be a periodof hypervigilancefor pressureulcer risk.



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to increase arterial pressure. In my study, the finding

may also represent a methodological limitation,

because measurement of blood pressures was con-

fined to the first 48 hours of the MSICU stay.

Although severity of illness was not predictive

of pressure ulcers in my sample, patients in whom

pressure ulcers developed had significantly highermean APACHE II scores (21.89; SD, 6.71) than did

patients who remained ulcer-free (mean, 14.63; SD,

2.65), suggesting that patients

with pressure ulcers had a greater

disease burden. This finding is

consistent with the results of a

previous study31 in ICU patients.

The APACHE II score (at 13)

was predictive of pressure ulcers

in only one study.1A total of 36

of the 347 patients in my sample

died, an overall mortality rate of10%. Among the patients who died during their

MSICU stay, almost half (17) had a pressure ulcer

at the time of death. Although APACHE II scores are

a valid measure of severity of illness and mortality

risk, they may not be a reliable empirical indicator

for severity of illness as a risk for development of

pressure ulcers.

LimitationsThe retrospective nature of this study is a limi-

tation. However, most of the data abstracted repre-

sent objective clinical data that would not vary on

the basis of the study design. Using only the Braden

Scale measurements recorded in the first 24 hours

of the ICU stay may also be a limitation; however,

determining risk early during a

patients stay is crucial because

the determination may result in

earlier implementation of pre-

vention strategies. The inability

to assess and stage developing

pressure ulcers is also a limita-

tion of a retrospective design.

Pressure ulcers were staged and

recorded in the patients recordby staff nurses who are educated annually on assess-

ment and staging of pressure ulcers and use of the

Braden Scale. Use of a single study site also dimin-

ishes the generalizability of the study findings.

ConclusionsCritical care patients are a unique subset of hos-

pitalized patients and are the sickest patients in the

health care system. ICU patients are repeatedly con-

fronted with multiple, concomitant risk factors for


development of pressure ulcers, and no consensus

exists on how best to measure these factors.3,13

Although specific measures of risk for pressure ulcers

are available for other populations of patients, includ-

ing children, neonates, patients who receive care at

home, patients who receive hospice and palliative

care, and patients with spinal cord injuries,17,18,48

nosuch tool exists for critical care patients, creating a

barrier to accurate assessment of risk for pressure

ulcers in ICU patients.

Accurate identification of risk factors is a pre-

requisite for determining appropriate strategies to

prevent pressure ulcers. However, even with consis-

tent and ongoing skin assessment, early identification

of skin changes, and the implementation of appro-

priate prevention strategies to minimize damage,

skin and tissue damage can occur in critically ill

patients.49 Certain prevention strategies, such as

turning of a patient whose hemodynamic status isunstable, may be medically contraindicated, and

adequate prevention of pressure ulcers in patients

with multiple risk factors is difficult.50 Paradoxically,

occurrence of pressure ulcers in hospitalized patients,

including critical care patients, is considered an

adverse event by the Centers for Medicare and Med-

icaid Services, leaving caregivers in a challenging sit-

uation of trying to prevent a pressure ulcer that may

not realistically be preventable. Continued research

on risk factors for pressure ulcers in critical care

patients is imperative, not only to ultimately decrease

the prevalence of pressure ulcers but also to help

caregivers identify and implement risk appropriate

evidence-based strategies to prevent the ulcers. Addi-

tionally, research will validate the existence of risk

factors for pressure ulcers that cannot be controlled

and thus are not preventable.

My results demonstrate the multifactorial causes

of pressure ulcers in critical care patients. Although

scores on 2 Braden subscale risk factors (mobility,

friction/shear) were predictive of pressure ulcers,

other risk factors not measured by the Braden Scale,

including age, length of ICU stay, norepinephrine

administration, and cardiovascular disease, also

were significant predictors in multivariate analysis.My findings underscore the need for develop-

ment and testing of model for assessing the risk for

pressure ulcers in ICU patients, in order to provide

a basis for explaining the development of pressure

ulcers in these patients. This model could serve as

the foundation for development of a pressure ulcer

risk assessment scale for critical care patients. Although

Pancorbo-Hildago et al51 have stated that use of a

risk assessment scale increases the implementation

of pressure ulcer initiatives, the ultimate test is the

Only mobility andfriction/shear

Braden subscaleswere predictors of

pressure ulcers.

A model forassessing pressure

ulcer risk in inten-sive care patients

is needed.



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ability to translate the findings of such an assessment

into a reduction in the occurrence of pressure

ulcers. Little evidence supports such a reduction

when current risk assessment tools are used.16,17,51-53

Many opportunities exist for research on the

effects of various prevention strategies, such as sup-

port surfaces, fecal containment devices, frequencyof repositioning, the use of topical dressings applied

to the sacrum to minimize friction/shear, progres-

sive mobility programs, and the use of glide sheets

and patient transfer equipment, on the development

of pressure ulcers in ICU patients. Ultimately, accu-

rate identification of the risk factors for pressure

ulcers and testing and implementing evidence-based

prevention strategies can lead to reductions in both

the occurrence of pressure ulcers and health care

costs and can promote positive health outcomes in

critical care patients.

ACKNOWLEDGMENTSThis research was done at Englewood Hospital andMedical Center.

FINANCIAL DISCLOSURESNone reported.

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SEE ALSO

For more about preventing pressure ulcers, visit theCritical Care NurseWeb site, www.ccnonline.org, andread the article by Jankowski, Tips for ProtectingCritically Ill Patients From Pressure Ulcers (April2010).



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CE Test Test ID A112005: Predictors of Pressure Ulcers in Adult Critical Care Patients. Learning objectives:1. Identify the stages of pressure ulcers asdefined by the National Pressure Ulcer Advisory Panel. 2. Describe the components of the Braden Scale for assessing risk for pressure ulcers. 3. Discuss poten-tial factors not included in the Braden Scale that can be predictors for pressure ulcers in critical care populations.

Program evaluation Yes NoObjective 1 was met Objective 2 was met Objective 3 was met Content was relevant to my

nursing practice My expectations were met This method of CE is effective

for this content The level of difficulty of this test was:

easy medium difficultTo complete this program,

it took me hours/minutes.

Test ID: A112005 Contact hours: 1.0 Form expires: September 1, 2013.Test Answers: Mark only one box for your answer to each question. You may photocopy this form.

1. Which of the following is the estimated percentage of hospitalacquired pressure ulcers in intensive care patients?a. 13% to 35% c. 16% to 63%b. 14% to 42% d. 17% to 71%

2. Which of the following explains the reasoning for the Centersfor Medicare and Medicaid Services limited reimbursementfor never events?a. They can be prevented by implementing evidence-based preven-tive measuresb. They are grounds for malpractice against the nursing staffc. They are unavoidable consequences of properly organized cared. They are inexpensive to treat

3. Which of the following Braden scores belongs to the patientwith a high risk for developing a pressure ulcer?a. 16 c. 11b. 13 d. 8

4. Which of the following pressure ulcer risk factors was notincluded as par t of the Braden Scale?a. Sensory perception c. Low arteriolar pressureb. Mobility d. Nutrition

5. Which of the following was i ncluded in the def inition oflow arteriolar pressure in the study?a. Number of hypotensive hours during intensive care unit (ICU) stayb. Mean arterial pressure


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