Validity of the Waterlow scale for pressure ulcer risk assessment in the intensive care unit: a prospective analysis of 698 patients

Critically ill patients are at a particular risk for developing pressure ulcers. Yet until now, no sufficiently specific, validated pressure ulcer risk assessment instruments exist for critically ill patients. In a prospective study of 698 patients of medical intensive care unit (ICU), we therefore analyzed if the Waterlow scale is suitable for pressure ulcer risk assessment in the ICU. Only patients with no pressure ulcer on admission to the ICU were included. The Waterlow scale was used to assess pressure ulcer risk on admission to the ICU, and the number of points on the scale were analyzed with regard to pressure ulcers development in the course of the ICU stay (121 patients). Our results show that adequate pressure ulcer risk assessment on admission to the ICU is not possible with the Waterlow scale. Sensitivity and specificity reached their maximal values of 64.6% and 48.8%, respectively, at a comparably high cut-off of 30 points on the Waterlow scale (positive and negative likelihood ratio being 1.26 and 0.73, respectively). The area under the curve (AUC) was 0.59 in the receiver-operator-characteristic curve. Adding intensive care related parameters to the scale yielded some degree of improvement (AUC 0.69), but the development of ICU specific pressure ulcer risk scales still seems to be necessary to allow reliable pressure ulcer risk assessment in the ICU.     

Pressure sores in intensive care: defining their incidence and associated factors and assessing the utility of two pressure sore risk assessment tools.

Patients in intensive care units (ICU) are at high risk of developing pressure sores and the use of pressure sore risk tools has been advocated as a means of identifying patients at risk. A prospective multi-site observational study was conducted to define the incidence of pressure sores, assess two pressure sore risk scales and to define risk factors relevant to intensive care. Patients (n = 534) were assessed for the presence of pressure sores. The Waterlow and Jackson/Cubbin risk scales were completed each day for 314 and 188 of these patients respectively. A total of 75 pressure sores were recorded. Of these, 34 were present on admission. Of the remaining 41, 16 were classified as Grade 1 and 24 as Grade 2 sores. The pressure sore (PS) incidence was 5.2 per cent. Expressed as PS/1000 patient days there were 18.48 pressure sores per 1000 patient days. The ability of the risk scores to predict pressure sores was tested using a Receiver Operating Characteristic (ROC) analysis. The association of risk score with pressure sores was analysed using a survival function (Kaplan Meier) and variables compared using a logrank test (Mantel-Cox). Factors associated with pressure sore occurrence were developed and tested using a survival regression model. Both risk scales were poor predictors of pressure sores (ROC curve area approximately 70 per cent for both). The factors, coma/unresponsiveness/paralysed & sedated and cardiovascular instability were significantly associated with pressure sores with relative risks of 4.2 and 2.5 respectively. Risk increased as a function of time such that the cumulative risk was 50 per cent at 20 days.     

La escala APACHE III: un factor pronóstico en la aparición de úlceras por presión en una Unidad de Cuidados Intensivos

ObjectiveTo analyze total APACHE III score association to pressure ulcers development in patients hospitalized in an intensive care unit (ICU).Material and methodsProspective cohort study conducted in an intensive care unit of the Hospital General de VIC. All the patients hospitalized between January 2001 to December 2001 were enrolled. Age, gender, length of stay, total Norton and APACHE III score and pressure sore development were collected.ResultsPressure sore incidence was 12.5% of the patients. The factors were significantly associated with the appearance of pressure sores in those patients with a length of stay in the intensive care unit, total Norton and severity of the disease measured by the APACHE III score. Patients having the greatest risk of pressure ulcers development were those whose Norton score was less than or equal to 14, and an APACHE III score higher than or equal to 50 (Odds Ratio: 37.9, 95% CI 11.16-128.47)ConclusionThe severity of the diseases measured with the APACHE III scale showed a relationship with the appearance of in-hospital pressure ulcers.The joint use of the APACHE III and Norton scale could be a good strategy to detect patients with very high risk of suffering pressure sores.     

A study of the prevention and management of pressure sores

Objectives: (1) To determine if there was an association between pressure sore risk assessment, severity of sore and planning of patient care and (2) to identify the methods used to prevent and treat pressure sores.Design: The study was a two-phase non-experimental design.Methods: All patients had pressure sore risk assessed on admission and discharge. They were scored according to the Waterlow system or the Stirling Pressure Sore Severity Scale. Nominal data were analysed by χ² and grouped data by Kruskal–Wallis ANOVAR.Setting: 500 bedded acute care hospital trust in Scotland.Sample: 30 Registered Nurses and 327 patient records.Results: Significant relationships were detected:

• 1.Between the Waterlow score and pressure relief (χ²=32.92, df=2, p<0.001) between the Waterlow score and patient education (χ²=6.04, df=2, p<0.05).
• 2.Between care plan type and pressure relief (χ²=38.3, df=2, p<0.01) mobilisation (χ²=12.1, df=2, p<0.016) and patient education (χ²=40.8, df=2, p<0.01).

Therewas no significant relationship between Waterlow score and mobilisation (χ²=3.2, df=4, p=0.530) or between Waterlow score and severity of sore (df=4, p=0.7265).Conclusion: The initial Waterlow score was not predictive although the Stirling Pressure Sore Severity Scale was indicative of skin status. This study indicates that a number of issues need to be addressed. Of particular concern is that even when risk factors were identified for a patient, they were rarely taken into account when planning care. Furthermore, according to nurses’ own accounts and by patient record analysis, the Waterlow Risk Assessment Scale appears to be unreliable when used in clinical practice.     

An investigation into the use of serum albumin in pressure sore prediction

OBJECTIVES: To ascertain the relevance of serum albumin and serum sodium as predictors of pressure sores in addition to the Waterlow score. DESIGN: Observational study of patients at risk of developing decubitus ulcers. SETTING: Staffordshire, in the midlands of the United Kingdom. PARTICIPANTS: 773 elderly hospital in-patients of a district general hospital. MEASUREMENTS: Waterlow scores and serum albumin and sodium. Development of a pressure sore. RESULTS: Logistic regression analysis of serum albumin, serum sodium and the Waterlow score showed the Waterlow score and serum albumin were significant predictors of pressure sores. CONCLUSIONS: Serum albumin may, in this patient group (in-patients over 64 years of age), be a useful predictor of pressure sore occurrence, though further work is needed to establish whether this is the case. Risk assessment of pressure sores can possibly be improved by adding serum albumin to one of the pre-existing tools such as the Waterlow score.     

两种压疮危险评估表预测效果的比较研究

[目的]测量并比较Waterlow压疮危险评估表和Braden修订版压疮危险评估表的预测效果。[方法]分别用两种评估表对332例病人进行评分,分析不同临界值时敏感性、特异性、阳性预测价值、阴性预测价值。[结果]Braden修订版压疮危险评估表以19分为临界值、Waterlow压疮危险评估表以15分为临界值时敏感性、特异性、阳性预测价值、阴性预测价值等指标间能达到较好的平衡,且Braden修订版压疮危险评估表各指标均大于Waterlow压疮危险评估表;Braden修订版压疮危险评估表的ROC曲线下面积略高于Waterlow压疮危险评估表。[结论]Braden修订版压疮危险评估表和Waterlow压疮危险评估表都有较好的预测效果,尤其以Braden修订版效果更优。     

Incidence of pressure ulcers in a neurologic intensive care unit

OBJECTIVES: To determine the risk factors for pressure ulceration in an intensive care setting, to evaluate the Braden scale as a predictor of pressure ulcer risk in critically ill patients, and to determine whether pressure ulcers are likely to occur early in the hospital stay. DESIGN: Cohort study of patients with no preexisting ulcers with a 3-month enrollment period. SETTING: The neurologic intensive care unit and the neurologic intermediate unit at a primary care/referral hospital with a level I trauma center. PATIENTS: A total of 186 patients entered the study. INTERVENTION: Within 12 hrs of admittance, initial assessment, photographs, and Braden score were completed. Patients were re-examined every 4 days or at discharge from the unit, whichever came first. MAIN OUTCOME MEASURES: Determining risk factors for pressure ulcers, performing detailed statistical analyses, and testing the usefulness of the Braden score as a predictor of pressure ulcer risk. RESULTS: Twenty-three of 186 patients developed at least one pressure ulcer (incidence = 12.4%) after an average stay of 6.4 days. The Braden scale, which measures six characteristics of skin condition and patient status, proved to be a primary predictor of ulcer development. No ulcers developed in the 69 patients whose Braden score was 16 or higher. The likelihood of developing a pressure sore was predicted mathematically from the Braden score. However, being underweight was a significant and distinct factor in pressure ulcer development. CONCLUSIONS: Pressure ulcers may develop within the first week of hospitalization in the intensive care unit. Patients at risk have Braden scores of < or = 16 and are more likely to be underweight. These results suggest that aggressive preventive care should be focused on those patients with Braden scores of < or = 13 and/or a low body mass index at admission.     

Monitoring the pressure sore problem in a teaching hospital

During 1989 and 1990 a senes of three prevalence surveys were undertaken in a West Midlands teaching hospital to identify the numbers of patients at risk of developing pressure sores and the actual number of patients with pressure sores, prior to the purchase of pressure relieving equipment A further survey was undertaken in January 1993 to examine any improvement in pressure sore prevention strategies and in the care of those with established pressure sores All in-patients were assessed using the Waterlow score Full details of all pressure sores and any pressure relieving equipment in use was recorded The findings were compared with those of the first survey in 1989 The prevalence for 1989 was 8 77%, and this had reduced slightly to 7 9% in 1993 There was no significant difference in these figures However, in 1989 35 patients had 64 pressure sores and in 1993 32 patients had 46 pressure sores There was a significant reduction in the actual numbers of pressure sores There was no significant difference in the grades of sores and the sacrum was the most frequent position in both surveys The survey showed an improvement in the management of established pressure sores There was little change in the patient populations with respect to the degree of risk of pressure sore development Using the Waterlow score, the numbers of patients found to be in the no risk, at risk, high risk and very high risk categories remained remarkably stable These surveys will continue to provide a basis for selecting pressure relieving equipment Measurement of pressure sore incidence is needed in the future to monitor the efficacy of the prevention programme     

Development of a new risk assessment scale for predicting pressure ulcers in an intensive care unit

Aims and objectives: The study aimed to evaluate the predictive validity and accuracy of a new pressure ulcer risk assessment scale in two Indonesia intensive care units (ICUs). Background: Several risk assessment scales have been designed to identify patients at risk of developing pressure ulcers in ICU. However, the relative weight of each variable that contributes to pressure ulcer development in these scales is not described to enable designing of a risk assessment scale. Currently, the risk factors contributing to pressure ulcer development include interface pressure, body temperature and cigarette smoking. Design: A prospective cohort study was conducted in two ICUs in Pontianak, Indonesia. Methods: A total of 253 patients were recruited to the study from both hospitals. Data collection included new risk assessment scale [i.e. the Suriadi and Sanada (S.S.) scale] scoring, demographic, pressure ulcer severity scores (based on the National Pressure Ulcer Advisory Panel) and skin condition measures. Using the S.S. scale, trained data collectors scored patients once and assessed the body temperature daily until patients were discharged. Additionally, daily data were also collected in relation to the patient‘s skin condition and stage of pressure ulcer. Results: Out of the 253 patients, 72 (28·4%) developed pressure ulcers. In ICU A, the incidence was 27%; pressure ulcers developed into stage I (41·7%), stage II (45·8%), stage III (10·4%) and stage IV (2·1%). In ICU B, the incidence was 31·6%; the development of pressure ulcers was 48% in stage I and 52% in stage II. Using the predictive validity test, the S.S. scale balanced sensitivity (81%) and specificity (83%) at a cut‐off score of 4. The area under the receiver‐operating characteristic curve was 0·888 (confidence interval: 0·84–0·93). Conclusion: The S.S. scale was found to be a valid risk assessment tool to identify the patients at risk of developing pressure ulcers in Indonesia ICU.     

Prevalence of decubitus lesions in a hospital in Lombardia

A one day prevalence survey was performed in a University Hospital, with the aim of assessing the risk of developing a pressure sore by patients systematically assessed with the Waterlow Scale. Out of the 141 at risk patients, 16 had a pressure sore (11.3%). For six of them the sore was already present at admission so that the in hospital incidence was 7% (10 patients). Most at risk patients (74.4) were still cared on a standard mattress. The advantages and limits of prevalence surveys are discussed at the end of the three articles that present a prevalence survey, an incidence survey and the study of sentinel events.     

Inter-rater reliability and Waterlow's pressure ulcer risk assessment tool

AIM: To ascertain whether a lack of inter-rater reliability with the original Waterlow (1996) pressure ulcer risk assessment scale is due to different perceptions of patients by nurses or different interpretations of Waterlow as a tool. METHOD: A sample of 110 qualified nurses, who used the Waterlow pressure ulcer risk assessment scale in their daily work and were delegates at five study days, were given a case study and an uncompleted copy of the tool. They were asked to complete a risk assessment for the patient. The risk assessment score obtained by delegates was analysed using the Wilcoxon Signed Rank Test to measure the null hypothesis that there is no significant difference between the median of the nurses' scores and the patient's actual or 'gold standard' score. RESULTS: Nurses tend to over-rate (n=72, 65 per cent) rather than under-rate (n=25, 23 per cent) the patient's risk of developing a pressure ulcer. Only 13 of the 110 nurses (12 per cent) accurately rated the patient's score as 18. The Wilcoxon Test rejected the null hypothesis that there was no difference in the risk scores arrived at by individual nurses and the patient's actual score, that is, there is a significant difference between the scores obtained by the nurses in the study and the gold standard score. CONCLUSION: The results show poor inter-rater reliability when using the Waterlow pressure ulcer risk assessment scale. Part of the problem is that nurses are not using the tool in the way it was intended.     

Predictive risk scales for development of pressure ulcers in pediatric patients admitted to general ward and intensive care unit

BACKGROUNDMore than ten special scales are available to predict the risk of pressure ulcers in children. However, the performances of those scales have not yet been compared in China. AIMTo compare the Waterlow, Braden Q, and Glamorgan scales, and identify more suitable pressure ulcer evaluation scale for the pediatric intensive care unit (PICU).METHODSTrained nurses used the Waterlow, Braden Q, and Glamorgan scales to assess pediatric patients at Sun Yat-sen Memorial Hospital (China) within 24 h of admission from May 2017 to December 2020 in two stages. Skin examination was carried out to identify pressure ulcers every 3 d for 3 wk. RESULTSThe incidence of pressure ulcers was 3/28 (10.7%) in the PICU and 5/314 (1.6%) in the general pediatric ward. For children in the general ward, the Waterlow, Braden Q, and Glamorgan scales had comparable area under the operating characteristic curve (AUC) of 0.870, 0.924, and 0.923, respectively, and optimal cut-off values of 14, 14, and 29 points. For PICU, the Waterlow, Braden Q, and Glamorgan scales had slightly lower AUC of 0.833, 0.733, and 0.800, respectively, and optimal cut-off values of 13, 16, and 27 points. Braden Q demonstrated a satisfactory specificity, and during the second stage of the study for PICU patients, the AUC of the Braden Q scale was 0.810, with an optimal cut-off value of 18.35 points.CONCLUSIONThe Waterlow, Braden Q, and Glamorgan scales have comparable performance, while the Braden Q scale demonstrates a better specificity and can be successfully used by pediatric nurses to identify patients at high risk of pressure ulcers in PICU.     

Investigating the reliability and validity of the waterlow risk assessment scale: a literature review

The aim of this review was to examine health literature on the reliability and validity of the Waterlow pressure sore assessment scale. A systematic review of published studies relating to the topic was conducted and literature was examined for its relevancy to the topic under investigation. Findings suggest that despite the availability of over 40 assessment tools, the Waterlow assessment scale is the most frequently used by health care staff. Research suggests that the Waterlow Scale is an unreliable method of assessing individuals at risk of pressure sore development with all studies indicating a poor interrater reliability status. Its validity has also been criticized because of its high-sensitivity but low-specificity levels.     

The ability of the Simplified Acute Physiology Score (SAPS II) to predict outcome in coronary care patients

Objective: To evaluate the applicability of the Simplified Acute Physiology Score (SAPS II) for coronary care patients. Design: Prospective observational cohort study. Setting: Medical ICU of a community teaching hospital. Patients: 1587 consecutive patients admitted over a period of 18 months. Measurements and main results: Patients were divided in two groups according to the primary admission diagnosis: general medical intensive care (ICU) patients and intensive coronary care (CCU) patients. Score prediction was tested using criteria suitable to evaluate the discrimination and calibration properties of SAPS II. Mean SAPS II score was 31.6 (± 20.1) in ICU and 28.3 (± 15.5) in CCU patients (p = 0.06), mean risk of death 0.206 and 0.134 (p = 0.001), and observed hospital mortality 17.8 vs 10.3 %. The area under the receiver operating characteristic curve was 0.888 in ICU and 0.908 in CCU patients (p = 0.5). The correlation between predicted and observed hospital mortality was 0.62 (p = 0.001) in ICU and 0.66 (p = 0.001) in CCU patients. The calibration curves did not differ from each other. The probability of death in survivors and nonsurvivors was equally distributed in ICU and CCU patients (p = 0.5). Conclusion: We conclude that SAPS II is applicable to CCU patients in our unit. Received: 30 October 1996 Accepted: 7 August 1997     

A prospective study of fever in the intensive care unit

Objective: To determine the epidemiology of fever on the intensive care unit (ICU). Design: Prospective, observational study. Setting: Nine-bed general ICU in a 500-bed tertiary care inner city institution. Patients: 100 consecutive admissions of 93 patients over a 4-month period between July and October 1996. Interventions: All patients were seen and examined by one investigator within 24 h of ICU admission. Patients were followed up on a daily basis throughout their ICU stay, and all clinical and laboratory data were recorded during the admission. Measurements and results: Fever (core temperature ≥ 38.4 °C) was present in 70 % of admissions, and it was caused by infective and non-infective processes in approximately equal number. Most fevers occurred early in the course of the admission, within the first 1–2 days, and most lasted less than 5 days. The median Acute Physiology and Chronic Health Evaluation (APACHE) II score was 15 ( ± 0.6). The 70 episodes associated with fever at any time were associated with a significantly higher APACHE II score on admission than the afebrile episodes (15.8 ± 6.1 vs 12.1 ± 6.7, p = 0.04). The most common cause of non-infective fever was in the group designated post-operative fever (n = 34). All the patients in the post-operative fever group were febrile on day 0 or day 1; their mean admission APACHE score was 12.4 ( ± 4.4) compared to 15.9 ( ± 7.1) for the remaining patients (p = 0.01). Fever alone was not associated with a higher mortality: 26/70 (37 %) of febrile patients died, compared to 8/30 (27 %) of afebrile patients, (χ ² = 1.23, p = 0.38). Prolonged fever ( > 5 days) occurred in 16 patients. In 13 cases, fever was due to infection, and in the remaining 3 both infective and non-infective processes occurred concurrently. The mortality in the group with prolonged fever was 62.5 % (10/16) compared to 29.6 % (16/54) in patients with fever of less than 5 days' duration, a highly significant difference (p < 0.0001). Conclusions: Fever is a common event on the intensive care unit. It usually occurs early in the course, is frequently non-infective and is often benign. Prolonged fever is associated with a poor outcome. Post-operative fever is a well-recognised but poorly defined syndrome which requires further study. Received: 29 December 1998 Final revision received: 16 March 1999 Accepted: 14 April 1999     

循证护理干预在ICU危重患者压疮防治中的应用

目的 探讨循证护理干预在ICU危重患者压疮防治中的应用效果,总结压疮护理经验,为制定护理方案提供参考.方法 选取2015年1月~2016年3月该院ICU危重患者50例为研究对象,依据随机数字表法分为干预组和对照组各25例,对照组患者实施常规护理干预,干预组在常规护理基础上施加循证护理干预,应用Braden压疮预测量表评估两组患者压疮恢复状况;应用SF-36生活质量评价量表评估两组患者生活质量;自制满意度调查问卷评估两组满意度.比较两组患者压疮发生率、压疮形成时间、压疮发生程度、Braden压疮评分、SF-36评分以及满意度.结果 干预组压疮发生率为4.00%,明显低于对照组的12.00%,差异有统计学意义(P<0.01);干预组压疮发生程度明显轻于对照组,差异有统计学意义(P<0.01);干预组压疮形成时间为(9.45±2.82)d,明显晚于对照组的(5.12±2.26)d,差异有统计学意义(P<0.01);干预组Braden压疮评分、SF-36评分均优于对照组(P<0.01);干预组总满意度为96.00%,高于对照组的84.00%(P<0.01).结论 循证护理干预在ICU危重患者压疮防治中有重要作用,可降低压疮发生率及发生程度,提高患者护理满意度及生活质量.     

Outcomes for haematological cancer patients admitted to an intensive care unit in a university hospital

Background

Haematological cancer (HC) patients are increasingly requiring intensive care (ICUs). The aim of this study was to investigate the outcome of HC patients in our ICU and evaluate 5 days-full support as a breakpoint for patients’ re-assessment for support.

Acute renal failure in the ICU: risk factors and outcome evaluated by the SOFA score

Objectives: To describe risk factors for the development of acute renal failure (ARF) in a population of intensive care unit (ICU) patients, and the association of ARF with multiple organ failure (MOF) and outcome using the sequential organ failure assessment (SOFA) score. Design: Prospective, multicenter, observational cohort analysis. Setting: Forty ICUs in 16 countries. Patients: All patients admitted to one of the participating ICUs in May 1995, except those who stayed in the ICU for less than 48 h after uncomplicated surgery, were included. After the exclusion of 38 patients with a history of chronic renal failure requiring renal replacement therapy, a total of 1411 patients were studied. Measurements and results: Of the patients, 348 (24.7 %) developed ARF, as diagnosed by a serum creatinine of 300 μmol/l (3.5 mg/dl) or more and/or a urine output of less than 500 ml/day. The most important risk factors for the development of ARF present on admission were acute circulatory or respiratory failure; age more than 65 years, presence of infection, past history of chronic heart failure (CHF), lymphoma or leukemia, or cirrhosis. ARF patients developed MOF earlier than non-ARF patients (median 24 vs 48 h after ICU admission, p < 0.05). ARF patients older than 65 years with a past history of CHF or with any organ failure on admission were most likely to develop MOF. ICU mortality was 3 times higher in ARF than in other patients (42.8 % vs 14.0 %, p < 0.01). Oliguric ARF was an independent risk factor for overall mortality as determined by a multivariate regression analysis (OR = 1.59 [CI 95 %: 1.23–2.06], p < 0.01). Infection increased the risk of death associated with all factors. Factors that increased the ICU mortality of ARF patients were a past history of hematologic malignancy, age more than 65 years, the number of failing organs on admission and the presence of acute cardiovascular failure. Conclusion: In ICU patients, the most important risk factors for ARF or mortality from ARF are often present on admission. During the ICU stay, other organ failures (especially cardiovascular) are important risk factors. Oliguric ARF was an independent risk factor for ICU mortality, and infection increased the contribution to mortality by other factors. The severity of circulatory shock was the most important factor influencing outcome in ARF patients. Received: 9 August 1999/Final revision received: 24 January 2000/Accepted: 6 April 2000