Research design
Phase 1
We developed a nurse-led RRS and activation criteria based on a literature review and the Delphi method. Information was extracted by systematically searching PubMed, EMbase, Web of Science, MEDLINE, China Biology Medicine Disc, (CBMdisc), China National Knowledge Infrastructure (CNKI), and the Wanfang database, followed by a preliminary construction of nurse-led RRS and activation criteria entry pool through panel discussions. The nurse-led RRS and activation criteria were then determined by the Delphi method. Delphi method is mainly sent questionnaire to experts by Wechat or email, and short message assisted reminder. According to the results of the consultation and the principle of information saturation, decide whether to carry out the next round of consultation. Indicators screening was based on the principle that the mean value of importance assignment ≥3.5 and the variable coefficient < 2.5.
Phase 2
We validated the pragmatic value of nurse-led RRS and activation criteria by a quasi-experimental study. The study flowchart was shown in the Fig. 1.
Study population
Experts
The study included 20 experts from the critical care field in China who have been engaged in acute and critical care nursing, critical care education, critical care medicine, critical care management, and other related work for more than 10 years, with a senior title or above. Experts can continue to participate in the consultation and solution process of this study.
Patients
Patients were those who met the RRS activation criteria and volunteered to participate in the study and were hospitalized in the emergency department of a third Grade A hospital in Gansu Province, and the third Grade A hospital is a large urban hospital that experiences rapid response requirements frequently. The patients were admitted from August 2020 to October 2021. Eligibility patients are all meets the following criteria (1) Patients aged ≥18 years; (2) Patients who met the RRT activation criteria; (3) Patients or their legal guardian signed informed consent. We excluded patients less than 18 years old, who were pregnant, or who had CPR performed on admission.
Sampling
The sample size of expert consultation is based on the information saturation principle, and we consulted 20 experts. Patients all came from a Grade A hospital in Lanzhou, Gansu Province. Sampling was by the convenience method. We included patients who met the inclusion criteria and were admitted to the emergency ICU from August to October 2020 and given the traditional rescue treatment and those who were admitted to the emergency ICU from August to October 2021 and treated with a nurse-led RRS.
Ethical approval of the study protocol
The study protocol was approved (2020–215) by the Ethics Committee of Gansu Provincial Hospital (Lanzhou, China). Written informed consent was obtained from all study participants and their guardians.
Intervention
The patients who met the inclusion criteria and were admitted to the emergency ICU from August to October 2020 were control group. The traditional rescue process, the emergency department physician responsibility system, was implemented in the control group. The nurses cooperated with the physicians to rescue patients according to the physician’s advice. The rescue process preliminarily judges the condition and provides life support at the same time; nurses assist in examination, invite specialist consultation according to the situation, and implement care according to the consultation opinion.
The intervention group strictly followed the nurse-led RRS implementation process (Fig. 2) and the RRS activation criteria which showed in the supplementary 2. Intervention group patients who were admitted to the emergency ICU from August to October 2021 and treated with a nurse-led RRS. Firstly, the nurse-led RRS implementation process was that everyone initiates the RRS according to the activation criteria, and the nurse-led RRT must respond within 1 min and perform rescue within 4 min. Secondly, the nursed-led RRT initiate emergency response. The leading nurse is responsible for evaluating the condition and directing the whole scene, the leading doctor is responsible for implementing rescue measures, others responsible for ECG monitor, defibrillation, establishing venous access, and so on. After the rescue, the nurse-led RRT will holding a consultation to discussion treatment and nursing care plan of the patient with attending physician. The detailed implementation process were showed in the supplement 1.
Outcome indicators
Outcome indicators were the success rate of rescue, rate of cardiac arrest, unplanned ICU admission, and effective time of rescue.
(1) success rate of rescue(%) = Number of patients successfully rescued/ Total number of patients rescued*100%. The number of patients successfully rescued were included patients who survived at the time of discharge, and the total number of patients rescued were included patients.
(2) Rate of cardiac arrest(%) = Number of patients with cardiac arrests / Total number of patients rescued*100%.
(3) Unplanned ICU admission(%) = Number of emergency patients are admitted to ICU due to changes in their condition/ Total number of patients rescued*100%.
(4) Effective time of rescue: it was the time interval from cardiac arrest to stable recovery of vital signs.
Statistical analysis
Variables are presented as either mean with standard deviation or median with an interquartile range (IQR), as appropriate. We compared the outcome index in implementing a nurse-led RRS and activation criteria and routine rescue process. Student’s t-test was used to compare continuous variables, and the chi squared test or Fisher’s test was used to compare categorical variables. All P-values were two-tailed, and P-values of less than 0.05 were considered statistically significant. IBM SPSS® Statistics (version 22.0; IBM Corp., Armonk, NY, USA) was used for all statistical analyses.