Abstract
BACKGROUND:
Population aging is a social problem that is being faced in most countries.
OBJECTIVE:
To apply the National Early Warning Score (NEWS) for an early warning on the vital signs and consciousness of elderly patients who are hospitalized in the gastrointestinal surgical department and to provide a reference for early detection of changes in illness severity in elderly patients by studying the correlation between NEWS value and changes in illness severity.
METHODS:
We enrolled 528 elderly patients who were hospitalized in the gastrointestinal surgical department of a tertiary grade A hospital in Guizhou Province between June 2020 and May 2021, to analyze how NEWS max value correlates with illness severity and obtain the optimal NEWS cutoff value for both potentially critically ill and critically ill elderly patients using the receiver operating characteristic (ROC) curve.
RESULTS:
There were statistically significant differences in NEWS values between elderly patients with various illness severities (
CONCLUSION:
An early warning on the vital signs and consciousness of hospitalized elderly patients using NEWS can facilitate advanced detection of changes in illness severity of elderly patients by medical staff and enable timely treatment, thus significantly lowering the risks of illness deterioration.
Introduction
Population aging is a social problem that is being faced in most countries. The number of elderly people is rising annually, as is the number of elderly people who develop illnesses or undergo surgeries. In America, gastrointestinal diseases consume more medical resources than other common diseases, and the expense will continue to increase [1]. In China, gastrointestinal diseases are among the most prevalent diseases among the elderly population (24.53%) [2]. Aging causes the body to gradually lose its physiological integrity, which is then followed by physiological dysfunction or even death. For instance, aging can negatively impact peristalsis, digestion, and absorption functions of the stomach and intestine. Elderly patients with gastrointestinal disorders should be closely observed during their treatment in case there are changes in the severity of their illness.
Abdominal surgery, the primary treatment approach for gastrointestinal diseases, is one of the prevalent procedures among elderly patients [3]. Elderly patients have a poor stress response and more underlying conditions that are concealed and atypical in symptoms. Thus, elderly patients are more likely to experience changes in illness severity following surgeries. Subtle changes in their vital signs are potential predictors of the risk of their illness worsening [4]. Anesthesia and trauma brought on by abdominal surgery place an extra load on their hearts and impair the protection function of their lungs. Elderly patients have worse prognoses than young and middle-aged adults. This may show up as a higher risk of pulmonary infection, pulmonary embolism, arrhythmia, stress ulcer bleeding, or other complications. They may even suffer from dangerous outcomes such as multiple organ failures.
According to the results of previous research, early warning signs often show up several hours before a patient’s condition gets worse, as manifested by physiological indicator changes like changes in respiration, heart rate, blood pressure, consciousness, and oxygen saturation [5, 6]. Timely detection of these early warning signs and appropriate interventions can improve patient safety [7].
The UK Emergency Response Team (ERT) developed the Early Warning Score (EWS) based on abundant clinical research, for the timely detection of potentially critically ill patients. Later, Subbe et al. modified and developed EWS to establish the Modified Early Warning Score (MEWS), which is mainly employed to predict the illness trends and prognoses of patients who visited emergency departments. Medical staff can select an appropriate treatment based on MEWS values. For better clinical applicability, the UK Royal College of Physicians further modified and developed MEWS to establish the National Early Warning Score (NEWS) in 2012. In addition to the items in MEWS – patient temperature, respiratory rate, heart rate, systolic blood pressure, and state of consciousness, the 20-point NEWS additionally included two indicators – oxygen saturation and oxygen inhalation intervention, and made minor adjustments to the values assigned to each vital sign indicator. After NEWS was published, it was popularized and applied by a great number of medical institutions in the UK [8].
In first-line clinical practice, the timely application of appropriate disease assessment tools to predict risk [9, 10] and identify the condition of potentially critically ill or critically ill patients and to objectively and scientifically assess the severity of their illness, is important. These tools help medical professionals make prompt assessments of patient conditions and decide on interventions [11].
In this paper, MEWS and NEWS scoring systems were used to objectively quantify the relevant physiological indicators, compare the correlation between the two and different disease degrees of patients and the sensitivity of clinical identification of patients’ disease, and determine the trigger value of early warning of disease changes, so as to provide a basis for clinical nurses to rationally select the disease assessment system to observe the condition of patients after surgery.
Study participants and methods
Study participants
This prospective, observational study was conducted over a year, between June 2020 and May 2021. A total of 594 patients were collected, 66 patients who were directly transferred to the intensive care unit (ICU) were excluded, and 528 elderly patients were finally included in this study. There are 350 men and 178 women, aged 68.35
Inclusion criteria: (1) Patients who were aged 60 or above. (2) Patients who underwent gastrointestinal surgeries. Exclusion criteria: (1) Patients with multiple organ failures and critical conditions on admission. (2) Patients who were transferred directly to ICU (intensive care unit) following surgery. (3) Patients who were transferred to other departments during the observation period and failed to have their complete set of relevant data collected.
This study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the Affiliated Hospital of Zunyi Medical University. Written informed consent was obtained from all participants.
Research tools
(1) MEWS [12]: a 14-point scale consisting of 5 physiological indicators: consciousness, body temperature, heart rate, respiration, and systolic blood pressure.
(2) The United Kingdom (UK) NEWS [8]: a 20-point scale consisting of 6 physiological indicators: body temperature, heart rate, respiration, oxygen saturation, systolic blood pressure, and consciousness.
Research methods
Grading of illness severity
Grading of illness severity in this study was based on the Nursing Classification issued by the National Health Commission of China and the actual conditions of patients [13]. Nursing Classification segregates nursing into four grades: Special Care, Primary Care, Secondary Care, and Tertiary Care. As this study is centered on illness severity, we excluded the section on self-care ability in Nursing Classification. Then, we referred to the description of illness severity in Nursing Classification and subdivided the Primary Care section into two parts to form a five-grade classification (Table 1) of the severity of patient illness.
Illness severity grading
Illness severity grading
Nursing staff in the gastrointestinal department were imparted instruction about NEWS and MEWS theory and our research team members conducted simulation practice training for the nurses. The nurses were also trained for standardized operations in collecting and recording physiological indicators and for developing a stronger awareness on the need for objectively quantifying the severity of illness in patients.
Items studied
Based on the data from the medical record department and information department, two members of our research team took the time point of the patients’ return to wards following their surgeries as the observation start point to obtain relevant indicators of the patients according to NEWS, MEWS; the time point when patients began to exhibit need for intensive care, rescue, change of status to critically or terminally ill as determined by doctors, or other terminally or critically ill indicators, or when patients died, as the observation endpoint. Based on these observations, the following research was carried out: how NEWS and MEWS values correlate with the severity of illness; to obtain early warning trigger values of patients with various illness severities like potentially critically ill, critically ill, and terminally ill through the receiver operating characteristic (ROC) curve; to compare the accuracy of NEWS and MEWS in predicting the illness severity of patients.
Quality control
We adopted on-site questioning and awarded respondents for successfully answering the questions. We evaluated the outcomes of the previously mentioned training of medical staff and also clarified the doubts of the medical staff and provided retraining.
We designed data collection forms that could record all pertinent data in detail and completely.
Two members of our research team were engaged in data collection – one was responsible for data collection and recording, while the other was responsible for checking and verifying the data. This division of labor ensured data accuracy and reliability.
Statistical analysis
SPSS Statistics 18.0 and Spearman’s rank correlation coefficient were applied for correlation analysis. MedCalc statistical software (version 12.7) was used to plot the ROC curve to determine the trigger value, sensitivity, specificity, and Youden’s index for illnesses of different severities.
Results
Analysis of how NEWS and MEWS correlate to the illness severity of patients
According to our findings, NEWS and MEWS values correlated to the illness severity of patients: the more severe the illness, the higher the NEWS and MEWS values. The NEWS and MEWS values correlated positively with illness severity. There were statistically significant differences between different illness severities (
Correlation between illness severity and scores
Correlation between illness severity and scores
Note: MEWS, Modified Early Warning Score; NEWS, National Early Warning Score. Comparison between a and grade V,
We plotted an ROC curve where the illness severity of the patient was used as the assessment indicator and applied it to assess illness sensitivity and specificity of NEWS and MEWS, with statistically significant differences in the results (
Accuracy of NEWS and MEWS in detecting potentially critically ill patients
The AUC of MEWS was 0.875 (95% CI: 0.844, 0.902), the optimal cut-off value was 3 points, the sensitivity was 78.9%, the specificity was 78.4%, and the Yodon index was 0.5732. The AUC of NEWS was 0.907 (95% CI: 0.878, 0.930), the best cut-off value was 5 points, the sensitivity was 82.4%, the specificity was 83.6%, and the Yoden index was 0.6599 (Fig. 1).
A: Receiver Operator Characteristic (ROC) curve of Modified Early Warning Score (MEWS)-based assessment of potentially critical illness. B: Receiver Operator Characteristic (ROC) curve of National Early Warning Score (NEWS)-based assessment of potentially critical illness.
The AUC of MEWS was 0.872 (95% CL: 0.840, 0.899), the best cut-off value was 4 points, the sensitivity was 79.3%, the specificity was 83.2%, and the Yoden index was 0.6245. The AUC of NEWS was 0.921 (95% CL: 0.891, 0.940), the best cut-off value was 7 points, the sensitivity was 89.0%, the specificity was 79.6%, and the Yoden index was 0.6862 (Fig. 2).
Accuracy of NEWS and MEWS in detecting terminally ill patients
The AUC of MEWS was 0.906 (95% CI: 0.877, 0.929), the best cut-off value was 5 points, the sensitivity was 78.4%, the specificity was 87.0%, and the Jordon index was 0.6543. The AUC of NEWS was 0.939 (95% CI: 0.915, 0.948), the best truncation value was 8 points, the sensitivity was 90.2%, the specificity was 86.0%, and the Jordon index was 0.7615 (Fig. 3).
Comparison and analysis of illness severity detection between MEWS and NEWS
Comparison and analysis of illness severity detection between MEWS and NEWS
Note: MEWS, Modified Early Warning Score; NEWS, National Early Warning Score. *P< 0.05.
A: Receiver Operator Characteristic (ROC) curve of Modified Early Warning Score (MEWS)-based assessment of critical illness. B: Receiver Operator Characteristic (ROC) curve of National Early Warning Score (NEWS)-based assessment of critical illness.
A: Receiver Operator Characteristic (ROC) curve of Modified Early Warning Score (MEWS)-based assessment of terminal illness. B: Receiver Operator Characteristic (ROC) curve of National Early Warning Score (NEWS)-based assessment of terminal illness.
In China, the evaluation criteria for tertiary general hospitals propose that timely detection and treatment of “potentially critically ill” patients in general wards is the key inspection content of ward quality management [13]. However, due to the shortage of human resources and insufficient monitoring equipment in general inpatient wards, the judgment of the nurses on the severity of the patient’s condition is mainly based on the doctor’s order and clinical experience, and the objective quantification of the condition cannot be achieved, and often cannot be timely Discover the risk of the patient’s condition worsening and delay the timing of effective treatment for the patient [14, 15]. In recent years, medical institutions at home and abroad often use some scales to judge the severity of patients’ conditions, such as the acute physiology and chronic health status (APACHE II) evaluation system [16, 17], which is widely used in clinical practice. Many indicators are needed, which can comprehensively evaluate the patient’s condition, but it takes a long time, and some indicators cannot be obtained timely and accurately in general inpatient wards and primary hospitals; secondly, Glasgow Score (GCS) and Trauma Index Score (TI) are also used in Condition assessment of specific populations [18], but these assessment tools cannot meet the needs of elderly patients in general inpatient wards whose condition changes rapidly and rapidly. Elderly patients with declining physiological function are often accompanied by weakened heart and lung function, and patients with gastrointestinal diseases often need oxygen therapy after surgery. We speculate that NEWS is more effective in predicting postoperative condition changes in elderly patients with gastrointestinal diseases specific. Some scholars used the NEWS score to conduct relevant research and analysis on the pre-examination evaluation, death prediction and condition assessment of elderly patients in the emergency department [19, 20, 21, 22, 23]. However, there are few reports on the application of the NEWS scoring system in general hospitalized elderly patients undergoing gastrointestinal surgery.
In this study, we used MEWS and NEWS to comprehensively assess patients with various severities of illness and found that the more severe the illness, the higher the values of MEWS and NEWS, indicating that both MEWS and NEWS positively correlate to illness severity. Spearman’s rank correlation coefficient
The area under the ROC curve (AUC) assesses the accuracy of illness severity assessment tools based on AUC values: the larger the AUC value, the more accurate the prediction ability of the illness severity assessment tool [27]. In this study, we applied MEWS and NEWS for the assessment of postoperative illness severity in elderly gastrointestinal patients. NEWS performed better in detecting patient illness severity than MEWS in AUC, sensitivity, specificity, and Youden’s index, with statistically significant differences (
Conclusion
Abnormal vital signs and changes in consciousness appear early in elderly patients who are subject to deteriorating conditions, and their conditions change quickly. To prevent the condition of the patient from getting worse, medical staff should dynamically observe changes in their conditions for timely and appropriate intervention. Therefore, an appropriate tool is needed to enable medical staff to detect patient deterioration trends earlier and cooperate with doctors to carry out prompt treatment, thereby ensuring a better outcome for patients. Due to their simplicity in acquiring parameters and swiftness in assessment, MEWS and NEWS facilitate fast and efficient early warning of elderly patients’ conditions, even in general wards. Notably, with respect to condition specificity in elderly patients, NEWS caters better to actual changes in patient condition than MEWS.
Footnotes
Conflict of interest
The authors have no conflict of interest to declare.
Funding
This study was supported by the Zunyi City Science and Technology Plan Project (HZ (2022) No. 216).
