Analysis of the preventive effect of evidence-based, non-pharmacological care bundles against delirium in intensive care unit patients

Abstract

BACKGROUND

Intensive care unit (ICU)-hospitalized patients have a high risk of developing delirium; however, the related diagnosis and treatment remain inadequate.

AIM

To clarify the preventive effect of evidence-based, non-pharmacological care bundles on delirium in ICU-hospitalized patients.

METHODS

A total of 149 ICU patients (May 2022-May 2025) were enrolled, including 72 patients in the control group receiving routine nursing and 77 patients in the research group receiving evidence-based, non-pharmacological care bundles. Comparative analyses were conducted regarding delirium occurrence (incidence, time of first occurrence, and duration), nursing complications (deep venous thrombosis, ventilator-associated pneumonia, and unplanned extubation), clinical indices (mechanical ventilation duration, ICU length of stay, hospitalization time, and sedative duration), cognitive function (Chinese version of the Johns Hopkins Adapted Cognitive Exam), sleep quality (Richards-Campbell Sleep Questionnaire), sedation level (Richmond Agitation and Sedation Scale), health status (Acute Physiology and Chronic Health Evaluation II), anxiety and depression (Hamilton Anxiety Scale/Hamilton Depression Scale), and nursing satisfaction.

RESULTS

Compared with the controls, the research group showed lower delirium incidence, fewer overall nursing complications, and shorter time of first delirium occurrence, delirium duration, mechanical ventilation duration, ICU stay, and hospitalization time. The research group also demonstrated reduced sedative and analgesic dosages; lower Richmond Agitation and Sedation Scale, Acute Physiology and Chronic Health Evaluation II, Hamilton Anxiety Scale, and Hamilton Depression Scale scores; and higher post-interventional Adapted Cognitive Exam and Richards-Campbell Sleep Questionnaire scores, as well as higher overall nursing satisfaction.

CONCLUSION

Evidence-based, non-pharmacological care bundles are highly effective in preventing delirium in ICU-hospitalized patients.

Key Words: Evidence-based; Non-pharmacological care bundles; Intensive care unit; Delirium; Preventive effect

Core Tip: This study aimed to optimize and strengthen delirium management in intensive care unit-hospitalized patients by implementing evidence-based, non-pharmacological care bundles. Through comprehensive analyses, this model was found to be effective in preventing delirium, reducing nursing-related complications, and accelerating recovery. It also significantly improved cognitive function, sleep quality, and overall health status. The intervention is both safe and effective, with profound clinical implications.

INTRODUCTION

Delirium is an acute disorder of cognition and consciousness, with an incidence of 35.0%-67.0% in hospitalized trauma patients and up to 71.0% in intensive care unit (ICU)-hospitalized individuals, imposing substantial burdens on patients and healthcare systems[1]. Clinical manifestations include fluctuating mental state changes, inattention, disordered thinking, and altered levels of consciousness, all of which tend to fluctuate throughout the day and negatively affect sleep quality[2]. Delirium is associated with adverse clinical outcomes, including prolonged hospitalization, increased one-year post-discharge mortality risk, and persistent cognitive impairment, thereby placing considerable pressure on patients and their families[3]. Although delirium affects a significant proportion of people, effective diagnostic and therapeutic approaches remain limited, warranting further exploration of management strategies[4].

Conventional nursing measures, including medication nursing, early activity nursing, and discharge guidance, have shown limited preventive effects[5]. Evidence-based, non-pharmacological care bundles represent a comprehensive intervention approach that integrates cognitive function training, early activity guidance, psychological support, sleep and pain management, and health education to reduce delirium risk[6]. Based on scientific evidence and accumulated clinical experience, this strategy combines multiple effective measures into an integrated intervention cluster, thereby maximizing synergistic preventive effect[7]. Bennett et al[8] reported ameliorative effects of evidence-based, non-pharmacological interventions on the behavioral and psychological symptoms of patients with dementia.

Given the limited literature on the preventive effect of evidence-based, non-pharmacological care bundles on delirium in ICU patients, this study focuses on this aspect. We hypothesize that this strategy is superior to conventional care in preventing delirium in ICU patients and therefore conducted a detailed evaluation. The findings are expected to provide an evidence-based foundation for optimizing delirium nursing management in ICUs, improving patient outcomes and the quality of intensive care.

MATERIALS AND METHODS

General data

A total of 149 ICU-hospitalized patients (May 2022-May 2025) were enrolled. Among them, 72 patients receiving routine nursing intervention constituted the control group, and 77 patients receiving evidence-based, non-pharmacological care bundles comprised the research group.

Eligibility criteria

Participants met all of the following criteria: (1) ICU inpatients; (2) Mechanical ventilation (MV) dependence ≥ 48 hours; (3) No arrhythmia or hemodynamic instability; (4) Clear consciousness, no history of psychotropic drug addiction; (5) Normal cognition and communication ability; and (6) Complete, authentic medical records and outpatient records.

Patients were excluded if they had any of the following: (1) Sever organ dysfunction (e.g., liver, kidneys, etc.); (2) Delirium before ICU admission; (3) Continuous coma; (4) Malignant tumor; (5) Arrhythmia or hemodynamic instability; (6) Coagulation dysfunction; (7) Pregnancy or lactation; and (8) Cognitive impairment, mental disorders, or neurovascular diseases.

Intervening methods

Routine nursing interventions, including medication nursing, early activity nursing, and discharge guidance, were provided for patients in the control group.

Medication nursing: The nursing staff administered anti-dementia medications as per the doctor’s instructions.

Early activity nursing: Nurses assisted the patients in performing passive limb movements at an early stage. Once the patients regained consciousness and could cooperate, they were encouraged to perform bedside limb joint movements once daily for 30 minutes.

Discharge guidance and follow-up: Before discharge, a 20-minute one-on-one health education session was provided, covering delirium prevention, rehabilitation precautions, and follow-up guidance. Telephone follow-ups were conducted at 1 month, 3 months, and 6 months post-discharge (10-15 minutes) to assess recovery and answer questions.

Evidence-based, non-pharmacological care bundles were implemented in the research group: (1) Cognitive function training: The training was conducted once daily for 20-30 minutes by a trained nurse. The training covered sensory training (explanation of causes and coordination methods) orientation training (time, place, people, and self; using clocks, calendars, and verbal inquiry), memory training (family-provided audio-visual materials and visiting conversations), execution function training (clock pointing or gesture imitation), and thinking ability training (simple calculations and graphic recognition); (2) Early progressive mobility: After a 24-hour ICU screening to exclude exercise contraindications, the patients gradually transitioned from passive/active joint movements to bedside sitting, standing, or walking depending on the patient’s cooperation and muscle strength. Training was performed 1-2 times daily (15-20 minutes per session) and adjusted according to the patient’s tolerance; (3) Psychological and sleep care: Psychological support was provided once daily in the afternoon through concise communication, family participation in cognitive training, and regular visits. Sleep care was implemented from 22:00 to 6:00, targeting ≥ 4 hours of continuous night-time sleep. The measures included light adjustment, noise reduction, eye mask provision, and schedule optimizing; and (4) Comprehensive symptom management: Analgesic and sedative drugs with lower risks of respiratory depression and delirium (e.g., dexmedetomidine) were selected. Pain was assessed every 4 hours using pain scales for corresponding management. Additionally, patients and their families were given 15-minute delirium-related education sessions upon patient enrollment and every Monday and Thursday afternoon, covering risk factors, early identification signals, and prevention strategies.

Detection indicators

Delirium occurrence. Delirium incidence, time of first occurrence, and duration were documented. Assessment was performed in two steps. First, patients were evaluated using the Richmond Agitation and Sedation Scale (RASS)[9]. A RASS score ≤ -4 prompted the discontinuation of the evaluation until re-evaluation after some time. When > -4, delirium was assessed using the Confusion Assessment Method for the Intensive Care Unit[10], including fluctuating consciousness, inattention, disordered thinking, and altered level of consciousness. The presence of fluctuating consciousness and inattention, plus either disordered thinking or altered level of consciousness, was considered a positive result.

Nursing complications: The incidence of deep venous thrombosis (DVT), ventilator-associated pneumonia (VAP), and unplanned extubation (UE) was recorded and calculated.

Clinical indices: (1) The MV duration; (2) ICU length of stay (ICU-LOS); (3) Hospitalization time; and (4) Sedative duration were recorded.

Cognitive function: Cognitive function was assessed using the Chinese version of the Johns Hopkins Adapted Cognitive Exam (ACE)[11], which includes 25 items (total score: 100) covering orientation, language competence, imitation ability, attention and calculation, and memory. Scores ≤ 28 indicate severe cognitive impairment, 29-55 indicate moderate cognitive impairment, and 56-90 indicates mild cognitive impairment.

Sleep quality: Sleep quality was evaluated using the Richards-Campbell Sleep Questionnaire (RCSQ)[12], which includes six night-time sleep domains; sleep depth, sleep latency, awakenings, return to sleep, overall sleep quality, and ICU environmental noise. Each item is scored using a 10-cm visual analog scale (0-100, worst to best). The total score is the mean of the six items, categorized as poor (0-25), fair (26-75), and good (76-100).

Level of sedation: Sedation levels pre-intervention and post-intervention were assessed using RASS. Scores > 2 or < 0 suggesting poor sedation.

Health status: Health status was evaluated pre-intervention and post-intervention using the Acute Physiology and Chronic Health Evaluation II (APACHE-II)[13], comprising acute physiology (0-60), age (0-6), and chronic health status (2-5) domains, totaling 0-71 points. Higher scores indicate poorer health status.

Anxiety and depression: Anxiety and depression were assessed using the Hamilton Anxiety Scale (HAMA) (14 items, total 0-56) and Hamilton Depression Scale (HAMD) (17 items, total 0-52) pre-intervention and post-intervention[14]. Higher scores indicate greater severity.

Nursing satisfaction: Nursing satisfaction was measured using a self-designed satisfaction questionnaire (total score: 100)[15]. The questionnaire was scored directly by patients, with a score of 90-100 indicating very satisfied, 70-90 satisfied, and < 70 dissatisfied. The total satisfaction rate was calculated as the percentage of very satisfied and satisfied cases.

Statistical analysis

Data were independently entered into Excel by two investigators and cross-checked. IBM SPSS 21.0 was used for data processing and analyses. Continuous variables are expressed as mean ± SD, and categorical variables as n (%). To identify statistical significance (threshold: P < 0.05), continuous variables were tested using independent sample t-test and one-way analysis of variance (for normally distributed data) or the nonparametric test (for non-normally distributed data). Within-group (pre-intervention vs post-intervention) differences in continuous variables were identified using paired t-test. Categorical variables were analyzed using the χ² or Fisher’s exact tests.

RESULTS

Baseline data

The baseline data of the control and research groups were clinically comparable, with no significant differences in gender, age, history of smoking, alcoholism, hypertension, diabetes, or disease type (P > 0.05; Table 1).

Table 1 Baseline information, n (%)/mean ± SD.

Indicators	Control group (n = 72)	Research group (n = 77)	χ2/t	P value
Sex			0.141	0.707
Male	38 (52.78)	43 (55.84)
Female	34 (47.22)	34 (44.16)
Age (years)	61.18 ± 7.74	62.44 ± 8.35	0.953	0.342
Smoking history	13 (18.06)	24 (31.17)	3.428	0.064
Alcoholism history	12 (16.67)	19 (24.68)	1.448	0.229
Hypertension history	37 (51.39)	34 (44.16)	0.780	0.377
Diabetes history	21 (29.17)	25 (32.47)	0.190	0.663
Disease type			1.969	0.579
Respiratory diseases	26 (36.11)	30 (38.96)
Cardiac-cerebral vascular diseases	21 (29.17)	23 (29.87)
Digestive diseases	19 (26.39)	14 (18.18)
Other	6 (8.33)	10 (12.99)

Occurrence of delirium

Delirium incidence was 27 cases (37.50%) in the control group and 15 cases (19.48%) in the research group. The time of first delirium occurrence was 2.00 (1.00, 3.00) days in the control group and 1.00 (1.00, 1.00) days in the research group, while delirium duration was 4.00 (2.00, 5.00) days and 2.00 (2.00, 2.00) days, respectively. Comparative analysis showed a significantly lower delirium incidence in the research group than in the control group (P = 0.015), along with shorter time of first delirium occurrence and duration (P < 0.001; Table 2).

Table 2 Occurrence of delirium, n (%)/mean (interquartile range).

Indicators	Control group (n = 72)	Research group (n = 77)	χ2/Z	P value
Delirium incidence	27 (37.50)	15 (19.48)	5.968	0.015
Time of first delirium occurrence (days)	2.00 (1.00, 3.00)	1.00 (1.00, 1.00)	3.854	< 0.001
Delirium duration (days)	4.00 (2.00, 5.00)	2.00 (2.00, 2.00)	3.789	< 0.001

Nursing complications

The incidences of DVT, VAP, and UE were recorded in both groups. A total of 21 cases (29.17%) occurred in the control group compared with 8 cases (10.39%) in the research group. The overall incidence of nursing complications was significantly lower in the research group (P = 0.004; Table 3).

Table 3 Nursing complications, n (%).

Indicators	Control group (n = 72)	Research group (n = 77)	χ2	P value
Deep venous thrombosis	4 (5.56)	0 (0.00)	-	-
Ventilator-associated pneumonia	7 (9.72)	3 (3.90)	-	-
Unplanned extubation	10 (13.89)	5 (6.49)	-	-
Total	21 (29.17)	8 (10.39)	8.369	0.004

Clinical indices

Clinical parameters, including MV duration, ICU-LOS, hospitalization time, and sedative duration, were assessed in both groups. Compared with the control group, the research group showed significantly lower values for MV duration (8.91 ± 2.97 days vs 10.90 ± 3.57 days), ICU-LOS [11.00 (10.00, 13.00) days vs 14.00 (11.00, 16.00) days], total hospitalization time [16.00 (13.00, 19.00) days vs 18.50 (16.00, 22.00) days], and sedative duration [3.00 (2.00, 3.00) days vs 5.00 (4.00, 7.00) days] (P < 0.001; Table 4).

Table 4 Clinical indices, mean ± SD/mean (interquartile range).

Indicators	Control group (n = 72)	Research group (n = 77)	t/Z	P value
Duration of mechanical ventilation (days)	10.90 ± 3.57	8.91 ± 2.97	3.708	< 0.001
Intensive care unit length of stay (days)	14.00 (11.00, 16.00)	11.00 (10.00, 13.00)	-3.428	< 0.001
Hospitalization time (days)	18.50 (16.00, 22.00)	16.00 (13.00, 19.00)	-4.087	< 0.001
Sedative duration (days)	5.00 (4.00, 7.00)	3.00 (2.00, 3.00)	-6.911	< 0.001

Cognitive function and sleep quality

Cognitive function and sleep quality were evaluated using the ACE and RCSQ, respectively. The data showed higher scores on both scales in the research group vs the control group (ACE: 85.90 ± 7.24 points vs 79.11 ± 6.55 points; RCSQ: 68.31 ± 6.59 points vs 56.90 ± 5.37 points; P < 0.05; Figure 1).

Figure 1 Cognitive function and sleep quality. A: Pre-interventional and post-interventional Adapted Cognitive Exam scores; B: Pre-interventional and post-interventional Richards-Campbell Sleep Questionnaire scores. ^aP < 0.05, ^bP < 0.01 for inter-group comparisons. ACE: Adapted Cognitive Exam; RCSQ: Richards-Campbell Sleep Questionnaire.

Level of sedation and health status

Sedation level and health status were assessed using RASS and APACHE-II, respectively. Baseline scores were comparable between groups [RASS: 3.00 (3.00, 4.00) points vs 3.00 (2.00, 4.00) points; APACHE-II: 21.29 ± 4.74 points vs 22.75 ± 4.40 points; P > 0.05]. After intervention, both scale scores decreased significantly in each group (P < 0.05). Post-intervention RASS scores were 2.00 (1.00, 2.00) in the control group and 1.00 (0.50, 1.00) in the research group, while APACHE-II scores were 16.39 ± 4.63 and 10.26 ± 4.03, respectively. Inter-group comparison showed significantly lower post-intervention scores in the research group (P < 0.01; Figure 2).

Figure 2 Sedation level and health status. A: Pre-interventional and post-interventional Richmond Agitation and Sedation Scale scores; B: Acute Physiology and Chronic Health Evaluation II scores pre-intervention and post-intervention. ^aP < 0.05 and ^bP < 0.01 vs before intervention. APACHE-II: Acute Physiology and Chronic Health Evaluation II; RASS: Richmond Agitation and Sedation Scale.

Anxiety and depression

Anxiety and depression were assessed using the HAMA and HAMD, respectively. Baseline HAMA scores were 20.42 ± 3.96 in the control group and 20.96 ± 4.29 in the research group, decreasing to 12.56 ± 3.72 and 8.66 ± 3.13 post-intervention, respectively. Baseline HAMD scores were 20.82 ± 4.42 and 20.55 ± 4.13, which decreased to 14.82 ± 4.78 and 12.66 ± 3.42, respectively. There were no significant differences between groups at baseline (P > 0.05). Post-intervention, both scale scores decreased significantly in both groups (P < 0.05), with greater reductions observed in the research group (P < 0.01; Figure 3).

Figure 3 Anxiety and depression assessments. A: Pre-interventional and post-interventional Hamilton Anxiety Scale scores; B: Hamilton Depression Scale scores pre- and post-intervention. ^aP < 0.05 and ^bP < 0.01 vs pre-intervention. HAMA: Hamilton Anxiety Scale; HAMD: Hamilton Depression Scale.

Nursing satisfaction

A total of 58 patients (80.56%) in the control group and 72 patients (93.51%) in the research group reported satisfaction with nursing care. The total satisfaction was significantly higher in the research group than in the control group (P = 0.018; Table 5).

Table 5 Nursing satisfaction, n (%).

Indicators	Control group (n = 72)	Research group (n = 77)	χ2	P value
Very satisfied	28 (38.89)	42 (54.55)	-	-
Satisfied	30 (41.67)	30 (38.96)	-	-
Dissatisfied	14 (19.44)	5 (6.49)	-	-
Nursing satisfaction	58 (80.56)	72 (93.51)	5.609	0.018

DISCUSSION

Delirium is a common and complex nervous system syndrome in ICUs, and its prevention and treatment can be implemented through both non-pharmacological and pharmacological approaches. Non-pharmacological interventions are recommended first-line therapy for adults and children, covering environmental regulation, cognitive function rehabilitation training, family nursing education, and music training[16]. In this study, evidence-based, non-pharmacological care bundles were compared with conventional care for delirium prevention in ICU patients, and the detailed results are reported below.

Our results showed that evidence-based, non-pharmacological care bundles effectively prevented delirium in ICU inpatients, reducing the incidence from 37.50% to 19.48% and significantly shortening both the time to first episode and the duration. These effects may be attributable to the multi-dimensional prevention strategy integrated in the care bundles, including cognitive function training, early progressive mobility, psychological and sleep care, and comprehensive symptom management. Hsiao et al[17] similarly reported that non-pharmacological interventions, including physical activity, repositioning, clinical adjustment, sensory stimulation, environmental regulation, and relaxation, effectively prevented delirium, consistent with our findings. Lange et al[18] further reported that an evidence-based non-pharmaceutical cluster strategy shortened delirium duration in ICUs, supporting this study’s findings. Additionally, this care bundle strategy contributed to reduced risks of developing nursing complications (e.g., DVT, VAP, and UE). This may be due to the early progressive mobility used in the evidence-based, non-pharmacological care bundles, which helps promote lower-limb muscle contractions and venous return, thereby reducing DVT risk. In this model, early activity nursing and optimized sedation management effectively shorten MV duration, which may reduce exposure to pathogenic bacteria invading the lower respiratory tract through endotracheal intubation and decrease VAP incidence. The comprehensive symptom management and 4-hourly pain assessment help optimize sedation depth and alleviate agitation, thereby reducing the risk of accidental extubation caused by physical discomfort. Yuyen et al[19] similarly observed that non-pharmacological interventions in surgical ICU patients reduced adverse events such as self-extubation and nosocomial infections, supporting our results. Moreover, significant reductions in MV duration, ICU-LOS, hospitalization time, and sedative duration were observed in ICU patients receiving the care bundle, indicating accelerated rehabilitation. The preventive effects of the intervention on delirium may contribute to these clinical benefits. Consistent with our findings, Deng et al[20] reported effective delirium prevention and markedly shortened ICU-LOS in critically ill patients receiving evidence-based, non-pharmacological interventions.

Furthermore, the cognitive function and sleep quality were significantly improved following implementation of the care bundles. This may be attributed to the strategy providing ICU patients with detailed and multi-dimensional cognitive function training, psychological and sleep care, and family involvement, which may synergistically enhance cognitive and sleep outcomes. Dai et al[21] demonstrated that evidence-based non-pharmaceutical care bundles effectively improved cognitive function, sleep quality, neurological function, and daily living ability in ICU patients, complementing this study’s results. Further findings indicate that the care bundles notably enhanced the sedation effects and overall health status in ICU-hospitalized patients. This can be partially explained by enhanced sedation effects under the evidence-based, non-pharmaceutical care bundle protocol, including the selection of analgesic and sedative agents (e.g., dexmedetomidine) with lower risks of respiratory depression and delirium. Psychological and sleep care may further promote patients’ physical and mental relaxation, improve their sleep quality, and reduce daytime anxiety and restlessness. By reducing the need for additional sedatives, this strategy promotes early rehabilitation and improve holistic health. Wang et al[22] similarly reported that evidence-based, non-pharmaceutical care bundles reduced the risk of in-hospital delirium and death. Additionally, anxiety and depression were significantly mitigated in elderly ICU patients receiving the care bundles. This effect may be explained by timely and effective psychological support, dynamic monitoring of emotional fluctuations, and proactive communication addressing patients’ concerns. Higher overall nursing satisfaction was also observed in the research group, reflecting greater acceptance and recognition of the strategy. This may be associated with reduced delirium and complications, accelerated rehabilitation, and significant improvements in cognitive function, sleep quality, sedation effect, and overall health status. Improved health status and nursing satisfaction were also reported among elderly ICU patients receiving this intervention[23].

CONCLUSION

In summary, evidence-based, non-pharmacological care bundles effectively prevent delirium in ICU-hospitalized patients by reducing delirium incidence, shortening delirium duration and ICU-LOS, and decreasing nursing complications and sedative exposure. This strategy also improves patients’ cognitive function and sleep quality, alleviates anxiety and depression, and enhances nursing satisfaction. Overall, this approach represents a safe and effective delirium prevention strategy that warrants broader clinical application.