Waterlow score for risk assessment in surgical patients: a systematic review

Validity and reliability of the Waterlow scale for assessing pressure injury risk in critical adult patients: A multi-centre cohort study

AIM

To evaluate the predictive validity and reliability of the Waterlow scale in critically adult hospitalised patients.

DESIGN

A multi-centre cohort study.

METHODS

This study was conducted in 72 intensive care units (ICUs) in 38 tertiary hospitals in Gansu Province, China. All adults admitted to the ICU for greater than or equal to 24 h without pressure injury (PI) on admission were screened by the Waterlow scale on admission, during ICU stay and ICU discharge from April 2021 to February 2023. Receiver operating characteristic (ROC) curves were used to determine a potential cut-off value for critical adult hospitalised patients. Cut-off values were then determined using Youden's index, and sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated based on these cut-off values. Test-retest reliability was used to evaluate inter-rater reliability.

RESULTS

A total of 5874 critical patients on admission were included, and 5125 of them were assessed regularly. The area under curve (AUC) was 0.623 (95% CI, 0.574-0.690), with a cut-off score of 19 showing the best balance among sensitivity of 62.7%, specificity of 57.4%, positive predictive value of 2.07% and negative predictive value of 99.08%. The test-retest reliability between the first assessment and the regular assessment was 0.447.

CONCLUSIONS

The Waterlow scale shows insufficient predictive validity and reliability in discriminating critical adults at risk of PI development. To further modify the items of the Waterlow scale, exploring specific risk factors for PI in the ICU and clarifying their impact degree was necessary. Risk predictive models or better tools are inevitable in the future.

PATIENT OR PUBLIC CONTRIBUTION

Patients or family members supported nurses with PI risk assessment, skin examination and other activities during the inquiry.

Incidence of cervical collar-related pressure injury in patients with head and neck trauma: A scoping review study

The use of the cervical collar to support the head and neck is inevitable in many patients with head and spinal cord injuries. One of the consequences of using this instrument is the development of pressure injuries. Therefore, in this review study, the incidence of as well as the risk factors for cervical collar-related pressure injury in this group of patients was evaluated. The current study is a scoping review conducted in 2022. Five scientific databases (PubMed, Scopus, Web of Science, ProQuest, and CINAHL), as well as Google Scholar, were searched for relevant studies published from 1990 to 2022 using the following keywords: trauma, spinal cord injury, head injury, head trauma, collar, cervical collar, cervical immobilization, risk factors, incidence, pressure injury, pressure ulcer, and bed sore. The search was performed independently by two researchers. Articles from the initial search were first recorded in special tables, and then, were reviewed and analyzed separately by two researchers. After extraction, information from each article was entered into a special table categorized by year, country, study design, study population, the incidence of cervical collar-related pressure injury, risk factors for cervical collar-related pressure injury, and grades of pressure injury. Of the 10 articles, 6 were retrospective cohort studies, 3 were cross-sectional descriptive studies, and 1 was a case report study. In terms of the study population, one study was conducted on pediatric patients, one was conducted on elderly patients, and eight were conducted on adults with head and neck trauma. In eight articles, the incidence of cervical collar-related pressure injury was reported. The reported incidence varied between 1.1% and 78.4%. In eight articles, risk factors for cervical collar-related pressure injury were reported. The most common risk factors were duration of cervical collar use, hospitalization in intensive care units, low level of consciousness, and longer hospital stay. The current review study showed that a significant percentage of head and neck trauma patients for whom cervical collar is used suffer from different grades of pressure injuries. Hence, healthcare providers should consider this issue when caring for this group of patients and take the necessary preventive measures in this regard. It should be noted that previous studies in this field had significant limitations, and thereby, it is strongly recommended to conduct further studies with a stronger methodology.

Pre-operative Waterlow score and outcomes after kidney transplantation

Background

Waterlow scoring was introduced in the 1980s as a nursing tool to risk stratify for development of decubitus ulcers (pressure sores) and is commonly used in UK hospitals. Recent interest has focussed on its value as a pre-op surrogate marker for adverse surgical outcomes, but utility after kidney transplantation has never been explored.

Methods

In this single-centre observational study, data was extracted from hospital informatics systems for all kidney allograft recipients transplanted between 1^st January 2007 and 30^th June 2020. Waterlow scores were categorised as per national standards; 0–9 (low risk), 10–14 (at risk), 15–19 (high risk) and ≥ 20 (very high risk). Multiple imputation was used to replace missing data with substituted values. Primary outcomes of interest were post-operative length of stay, emergency re-admission within 90-days and mortality analysed by linear, logistic or Cox regression models respectively.

Results

Data was available for 2,041 kidney transplant patients, with baseline demographics significantly different across Waterlow categories. As a continuous variable, the median Waterlow score across the study cohort was 10 (interquartile range 8–13). As a categorical variable, Waterlow scores pre-operatively were classified as low risk (n = 557), at risk (n = 543), high risk (n = 120), very high risk (n = 27) and a large proportion of missing data (n = 794). Median length of stay in days varied significantly with pre-op Waterlow category scores, progressively getting longer with increasing severity of Waterlow category. However, no difference was observed in risk for emergency readmission within 90-days of surgery with severity of Waterlow category. Patients with ‘very high risk’ Waterlow scores had increased risk for mortality at 41.9% versus high risk (23.7%), at risk (17.4%) and low risk (13.4%). In adjusted analyses, ‘very high risk’ Waterlow group (as a categorical variable) or Waterlow score (as a continuous variable) had an independent association with increase length of stay after transplant surgery only. No association was observed between any Waterlow risk group/score with emergency 90-day readmission rates or post-transplant mortality after adjustment.

Conclusions

Pre-operative Waterlow scoring is a poor surrogate marker to identify kidney transplant patients at risk of emergency readmission or death and should not be utilised outside its intended use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02902-8.

Quantitative analysis of heart rate variability parameter and mental stress index

Background

Cardiovascular disease not only occurs in the elderly but also tends to become a common social health problem. Considering the fast pace of modern life, quantified heart rate variability (HRV) indicators combined with the convenience of wearable devices are of great significance for intelligent telemedicine. To quantify the changes in human mental state, this article proposes an improved differential threshold algorithm for R-wave detection and recognition of electrocardiogram (ECG) signals.

Methods

HRV is a specific quantitative indicator of autonomic nerve regulation of the heart. The recognition rate is increased by improving the starting position of R wave and the time-window function of the traditional differential threshold method. The experimental platform is a wearable sign monitoring system constructed based on body area networks (BAN) technology. Analytic hierarchy process (AHP) is used to construct the mental stress assessment model, the weight judgment matrix is constructed according to the influence degree of HRV analysis parameters on mental stress, and the consistency check is carried out to obtain the weight value of the corresponding HRV analysis parameters.

Results

Experimental results show that the recognition rate of R wave of real-time 5 min ECG data collected by this algorithm is >99%. The comprehensive index of HRV based on weight matrix can greatly reduce the deviation caused by the measurement error of each parameter. Compared with traditional characteristic wave recognition algorithms, the proposed algorithm simplifies the process, has high real-time performance, and is suitable for wearable analysis devices with low-configuration requirements.

Conclusion

Our algorithm can describe the mental stress of the body quantitatively and meet the requirements of application demonstration.