Effect of microenvironment theory-based nursing on prognosis in intensive care unit patients with postoperative severe acute pancreatitis

Abstract

BACKGROUND

Patients with postoperative severe acute pancreatitis (SAP) in the intensive care unit (ICU) face complex challenges arising from physiological and microenvironmental imbalances, psychological stress, and the interaction of multiple environmental factors. Traditional nursing models inadequately address this integrated microenvironment, highlighting the need for microenvironment theory-based nursing interventions to optimize outcomes.

AIM

To evaluate the impact of a microenvironment theory-based nursing intervention model on the prognosis of patients with postoperative SAP in the ICU.

METHODS

Between January 2022 and December 2024, 106 patients with SAP who were admitted to ICU of the Fourth Affiliated Hospital of Soochow University (Suzhou Dushu Lake Hospital) were randomly assigned to two groups: (1) A control group (n = 53, routine care); and (2) An observation group (n = 53, routine care plus microenvironment theory-based nursing). Postoperative recovery, psychological distress, disease severity, and complication rates were compared between groups.

RESULTS

The observation group had significantly shorter postoperative flatus, defecation, and hospital stay compared with the control group (P < 0.05). The Hamilton Depression Rating Scale (17-item) and Hamilton Anxiety Rating Scale (14-item) scores in the observation group were significantly lower than those in the control group (P < 0.05). The observation group had a lower Acute Physiology and Chronic Health Evaluation II score (P < 0.05) compared with the control group. The postoperative complication rates were 5.66% (3/53) and 18.87% (10/53) in the observation group and control group, respectively (P < 0.05).

CONCLUSION

In patients with SAP, the microenvironment theory-based nursing intervention model facilitated postoperative recovery, alleviated depression and anxiety, reduced disease severity, and decreased postoperative complications.

Key Words: Severe acute pancreatitis; Intensive care unit; Microenvironment theory; Nursing intervention; Prognosis

Core Tip: This study focuses on patients with postoperative severe acute pancreatitis in the intensive care unit and innovatively introduces the microenvironment theory into the field of nursing. Traditional nursing models have limitations in addressing the complex physiological, psychological, and environmental needs of these patients. The intervention model based on microenvironment theory comprehensively considers the physiological microenvironment (e.g., sensory stimuli, physical conditions), psychological microenvironment (alleviating anxiety, reducing psychological stress), and therapeutic microenvironment (multidisciplinary collaboration, procedural protocols). Compared with routine care alone, this approach provides more comprehensive and nuanced nursing interventions.

INTRODUCTION

In recent years, the incidence of acute pancreatitis (AP) has gradually increased, largely because of changes in lifestyle and dietary habits. Epidemiological studies have indicated that the global number of AP cases increased from 1727800 in 1990 to 2815000 in 2019, representing a 62.9% increase[1]. Severe AP (SAP), a critical form of AP, is characterized by severe illness, frequent complications, and persistently high mortality rates, making it a major focus in the medical community[2,3]. Surgical intervention remains an important treatment modality for SAP, enabling surgeons to remove necrotic pancreatic tissue, drain abdominal fluid, and reduce inflammatory damage[4]. However, the surgical procedure itself constitutes major trauma, leaving patients extremely weak in the postoperative period and subject to a prolonged and challenging recovery process. During the convalescent phase, nursing interventions play a crucial role in directly influencing both recovery and prognosis.

Microenvironment theory-based nursing is a novel model based on environmental optimization principles. It aims to enhance patient comfort and recovery by regulating the physical ward environment and addressing psychological factors such as stress and emotional well-being[5]. Previous research has demonstrated that this model significantly improves patient experiences and promotes recovery in surgical settings such as rhinosinusitis[6]. Building on this premise, in the present study, we investigated the impact of a microenvironment theory-based nursing intervention model on the prognosis of patients with postoperative SAP in the intensive care unit (ICU).

MATERIALS AND METHODS

Study subjects

Between January 2022 and December 2024, 106 postoperative patients with SAP admitted to ICU of the Fourth Affiliated Hospital of Soochow University (Suzhou Dushu Lake Hospital) were enrolled and randomly assigned to either the observation group (n = 53) or the control group (n = 53). The inclusion criteria were as follows: (1) Age 18-70 years; (2) Met the diagnostic criteria for SAP[7] and underwent surgical treatment; and (3) Patients or their families provided signed informed consent. The exclusion criteria were as follows: (1) Surgery within the past 3 months; (2) Severe impairment of major organ functions (e.g., heart, brain, kidney); and (3) History of psychiatric disorders. This study was approved by Medical Ethics Committee of the hospital.

Interventions

Patients in the control group received routine postoperative care, including condition monitoring and life support, with continuous dynamic monitoring of vital signs (heart rate, blood pressure, respiratory rate, SpO₂), central venous pressure (CVP), and hourly urine output. Serum amylase, lipase, electrolytes, and other biochemical markers were regularly assessed, and fluid resuscitation and vasoactive drug dosages were adjusted according to medical orders. Organ support was provided, including mechanical ventilation and continuous renal replacement therapy as necessary. Basic and specialized care included repositioning and back percussion every 2 hours to prevent pressure injuries and hypostatic pneumonia, maintaining oral and perineal hygiene, and managing catheters (e.g., nasogastric tubes, urinary catheters, and abdominal drains). A strictly aseptic technique was used to prevent iatrogenic infections. Complication prevention and symptom management involved close monitoring of abdominal pain and distension, with vigilance for complications such as pancreatic necrosis and septic shock. Medications such as antibiotics, acid suppressants, and somatostatin analogs were administered according to orders, while parenteral nutritional support was provided to maintain metabolic balance. Additionally, psychological care and health education were offered, including explanations of disease progression and treatment to alleviate anxiety, along with dietary and activity guidance to promote recovery.

The observation group received microenvironment theory-based nursing interventions in addition to routine care. These interventions addressed three dimensions: (1) Physiological; (2) Psychological; and (3) Therapeutic microenvironments. Sensory modulation was emphasized for the physiological microenvironment. Nurses used a fixed, gentle tone to brief patients on procedures in advance, thereby reducing subconscious alertness. White noise machines were used to maintain alarm volumes below 60 dB, preventing fear triggered by sudden loud sounds. Tactile interventions included scheduled daily 5-minute hand massages, accompanied by soft speech and designed to establish a “touch = safety” conditioned reflex, along with the use of soft cushions to maintain natural posture and reduce muscle tension. Visual interventions included circadian rhythm-mimicking lighting and bedside curtains to shield patients from distressing scenes, thus preventing the disruption of biological rhythms and the triggering of fear memories. In addition, the ward environment was maintained quiet and comfortable with minimal noise and bright lights. The room temperature was kept at 24-26 °C, humidity at 50%-60%, and ventilation was provided at least thrice daily (≥ 10 minutes each), ensuring air circulation while preserving warmth. Regarding the psychological microenvironment, interventions were tailored to individual patient assessments. Nurses communicated proactively, listened attentively, and reinforced their confidence by explaining treatment progress and sharing successful recovery cases. During medical procedures, patients were reassured with gentle communication, clearly outlining the purpose, process, and precautions to reduce fear. Relaxation techniques and meditation were employed to alleviate tension. Given the restrictions on family visitation in the ICU, recordings of messages by family members or familiar ambient sounds (such as ocean waves or birdsongs) were played via headphones for 15-20 minutes, two to three times daily. For the therapeutic microenvironment, multidisciplinary collaboration was established by integrating surgical, critical care, nutritional, and rehabilitation resources to optimize postoperative management. Individualized parenteral nutrition plans were developed jointly with nutritionists, and energy requirements were calculated based on Acute Physiology and Chronic Health Evaluation II (APACHE II) scores. The nursing team ensured strict infusion control and aseptic practices to reduce catheter-related infections and metabolic complications. Collaboration with rehabilitation specialists supported early mobilization, progressing from passive joint exercises to sitting for hemodynamically stable patients, thereby reducing ICU-acquired weakness and mechanical ventilation duration. Standardized protocols for catheter maintenance were enforced to minimize bloodstream infections. A linked pain-agitation/sedation-delirium management strategy was applied using standardized tools, such as the Numeric Rating Scale for pain, and the Riker Sedation-Agitation Scale, enabling dynamic adjustment of analgesic and sedative regimens to ensure appropriate dosing and patient comfort. Fluid management was guided by a three-tier monitoring system: (1) Hourly recording of outputs (urine, gastric drainage); (2) Monitoring of CVP and infusion rates; and (3) Maintaining CVP at 8-12 cm H₂O, with urine output ≥ 0.5 mL/kg/hour. A daily 24-hour net balance was calculated, with a mildly positive balance (500-1000 mL) allowed during early resuscitation. Fluid types were adjusted based on bedside ultrasound of the inferior vena cava collapsibility and hematocrit values. Lactate, electrolyte, and creatinine levels were also monitored, with adjustments made if lactate levels exceeded 2 mmol/L or creatinine levels increased, thereby preventing fluid overload, intra-abdominal hypertension, or acute kidney injury.

Outcome measures

Postoperative recovery was assessed by recording the time to first flatus, time to first defecation, and the length of hospital stay (days). Psychological distress was evaluated using the 17-item Hamilton Depression Rating Scale (HAMD) and the 14-item Hamilton Anxiety Rating Scale (HAMA)[8,9]. Trained professionals conducted assessments before and after the intervention. The category of severity was determined as follows: (1) HAMD: Mild (8-16), moderate (17-23), severe (≥ 24); (2) HAMA: Normal (< 7), mild (8-14), moderate (15-23), and severe (≥ 24); and (3) Disease severity: APACHE II score. Postoperative complications included pulmonary infection, intra-abdominal infection, catheter-related infection, respiratory failure, and acute renal failure.

Statistical analysis

All data were analyzed using Statistical Package for the Social Sciences 20.0. Measurement data are expressed as mean ± SD and compared using the independent-samples t-test. Categorical data are expressed as n (%) and analyzed with the χ² test. Statistical significance was set at P < 0.05.

RESULTS

Based on the data presented in Table 1, there were no statistically significant differences in the baseline characteristics between the observation and control groups prior to the intervention. The mean age of patients in the observation and control groups was 55.42 ± 7.15 years and 54.83 ± 6.29 years, respectively (P = 0.656). The sex distribution was as follows: (1) 35 males and 18 females in the observation group; and (2) 28 males and 25 females in the control group (P = 0.166). The average body mass index was comparable between the two groups, with values of 23.33 ± 3.11 kg/m² and 22.52 ± 2.97 kg/m² for the observation and control groups, respectively (P = 0.173). The etiology of SAP was also similar, with the most common cause being biliary in both groups (21/53 in the observation group vs 25/53 in the control group), followed by hyperlipidemia, alcohol consumption, and other causes (P = 0.664).

Table 1 Baseline characteristics, mean ± SD.

Group	Age (years)	Sex (male/female)	Body mass index (kg/m²)	Etiology (biliary/hyperlipidemic/alcoholic/other)
Observed group (n = 53)	55.42 ± 7.15	35/18	23.33 ± 3.11	21/12/11/9
Control group (n = 53)	54.83 ± 6.29	28/25	22.52 ± 2.97	25/13/10/5
t/χ²	0.447	1.917	1.372	1.578
P value	0.656	0.166	0.173	0.664

The observation group demonstrated significantly shorter times to first flatus and first defecation, as well as a shorter length of hospital stay (P < 0.05) compared with the control group (Table 2).

Table 2 Comparison of postoperative recovery outcomes, mean ± SD.

Group	Time to first flatus (hours)	Time to first defecation (hours)	Length of hospital stay (days)
Observed group (n = 53)	52.49 ± 6.33	65.13 ± 7.88	23.53 ± 3.32
Control group (n = 53)	58.11 ± 6.74	73.53 ± 8.79	25.64 ± 4.16
t value	4.428	5.178	2.890
P value	0.000	0.000	0.005

Following the intervention, both groups showed reductions in HAMD and HAMA scores. However, the observation group had significantly lower scores compared with the control group (P < 0.05; Table 3).

Table 3 Comparison of post-intervention psychological distress scores, mean ± SD.

Group	Hamilton Depression Rating Scale		Hamilton Anxiety Rating Scale
	Before	After	Before	After
Observed group (n = 53)	23.08 ± 4.24	13.13 ± 3.05a	21.13 ± 4.09	12.42 ± 2.82a
Control group (n = 53)	22.34 ± 4.47	17.28 ± 3.16a	20.23 ± 3.85	15.17 ± 3.05a
t value	0.870	6.874	1.174	4.830
P value	0.387	0.000	0.243	0.000

^aP < 0.05 vs before intervention.

Comparison of acute physiology and chronic health scores

After the intervention, the observation group had lower APACHE II scores compared with the control group (P < 0.05; Table 4).

Table 4 Comparison of acute physiology and chronic health scores, mean ± SD.

Group	Before	After	t value	P value
Observed group (n = 53)	17.55 ± 3.57	8.79 ± 2.95	13.495	0.000
Control group (n = 53)	18.26 ± 3.76	10.36 ± 3.27	12.110	0.000
t value	1.007	2.588
P value	0.316	0.011

The incidence of postoperative complications in the observation group was 5.66% (3/53), which was significantly lower than the 18.87% (10/53) observed in the control group (P < 0.05; Table 5).

Table 5 Comparison of postoperative complication rates, n (%).

Group	Pulmonary infection	Intra-abdominal infection	Catheter-related infection	Respiratory failure	Acute renal failure	Total
Observed group (n = 53)	1 (1.89)	0 (0.00)	1 (1.89)	1 (1.89)	0 (0.00)	3 (5.66)
Control group (n = 53)	2 (3.77)	3 (5.66)	2 (3.77)	2 (3.77)	1 (1.89)	10 (18.87)
χ² value						4.296
P value						0.038

DISCUSSION

SAP is characterized by a complex pathogenesis primarily driven by pancreatic autodigestion, leading to hemorrhage, necrosis, and subsequent local or systemic complications[10,11]. The inflammatory cascade not only impairs pancreatic function but also contributes to multi-organ dysfunction, including acute respiratory distress syndrome (manifesting as dyspnea and hypoxemia), renal failure (resulting in metabolic waste accumulation and electrolyte imbalance), and circulatory collapse (presenting as shock), which can ultimately result in death. Additionally, gastrointestinal hemorrhage and coagulation disorders may occur, further exacerbating disease severity and increasing mortality risk[12]. Conventional nursing models have limited ability to address the multifaceted physiological, psychological, and environmental needs of patients with SAP. In contrast, microenvironment-based interventions aim to holistically optimize recovery by simultaneously targeting these domains.

This study demonstrated that the patients in the observation group had shorter times to first flatus and defecation, shorter hospital stays, and lower acute and chronic physiology scores compared with those in the control group. These findings suggest that microenvironment-based nursing models can enhance postoperative outcomes, improve the quality and effectiveness of nursing, and accelerate recovery. Interventions addressing the physiological microenvironment may create favorable conditions for recovery by minimizing adverse external stimuli. For example, regulating sensory stimulation through noise control and optimized lighting reduces patient stress responses, thereby lowering the secretion of stress hormones, such as adrenaline. This stress reduction may prevent the inhibition of gastrointestinal motility, thereby promoting earlier flatus and defecation[13,14]. Hand contact and comfortable positioning help relax the muscles, improve circulation, and enhance blood flow to the gastrointestinal tract, further supporting gastrointestinal recovery. Maintenance of an appropriate ward temperature, humidity, and ventilation enhances patient comfort, reduces environmentally induced stress, and fosters favorable conditions for rehabilitation, thereby shortening hospitalization and lowering disease severity[15]. Interventions in the therapeutic microenvironment can also promote patient rehabilitation through precise treatment and risk prevention. Individualized nutritional support improves intestinal mucosal function, promotes gastrointestinal peristalsis, and reduces recovery time for bowel function[16].

The present study also demonstrated that HAMD and HAMA scores were lower in the observation group compared with the control group, indicating that microenvironment theory-based nursing can effectively alleviate depression and anxiety. By strengthening communication, employing professional psychological assessments, and providing timely psychological counseling, nurses were able to identify and address negative emotions such as anxiety, fear, and depression. Playing recordings of familiar sounds and messages by family members further enhanced emotional support, reinforcing the perception of the patients that they were not alone. Improved psychological well-being positively influenced physical recovery, enhanced treatment compliance, and promoted better cooperation with nursing interventions. Patients who actively participated in their care by adhering to medication schedules and undergoing the recommended examinations and treatments were more likely to avoid complications. Psychological improvements can help regulate immune function, strengthen resistance, and reduce the risk of postoperative complications[17].

Complications in ICU patients with severe pancreatitis can significantly affect rehabilitation and quality of life while increasing pain and mortality. In the present study, the observation group had a significantly lower complication rate than the control group, suggesting that microenvironment theory-based nursing effectively prevented complications. Personalized nutritional support, tailored to the nutritional status and metabolic demands of the patient, ensures adequate nutrient intake and energy supply in the hypermetabolic state, thereby promoting tissue repair and functional recovery. Adequate nutrition strengthens immunity and reduces the incidence of infectious complications[18,19]. Additionally, standardized nursing procedures and integrated pain-agitation-delirium management reduced the risk of infection and other adverse outcomes. Early mobilization in collaboration with rehabilitation specialists improves muscle strength and functional independence, shortens the duration of mechanical ventilation and hospitalization, and ultimately reduces disease severity[20].

In summary, the microenvironment theory-based nursing model supports the postoperative rehabilitation of patients with SAP admitted to the ICU by alleviating discomfort, mitigating anxiety and depression, and reducing complication rates.

Despite its strengths, this study also has some limitations. First, it was conducted at a single center with a relatively small sample size, which may limit the generalizability of the findings. Future multicenter studies with larger sample sizes are warranted. Second, the intervention period was confined to ICU stay, and the long-term effects of microenvironment theory-based nursing on post-discharge quality of life and readmission rates were not evaluated. Third, the nursing interventions were comprehensive, making it difficult to isolate the individual contributions of each component (physiological, psychological, and therapeutic) to the overall outcomes. Further research should employ a factorial design to address this issue.

CONCLUSION

The nursing intervention model based on microenvironment theory provides comprehensive and systematic care for patients with SAP in the ICU, addressing physiological, psychological, and social dimensions. This approach effectively improves the patient microenvironment, promotes physical rehabilitation, reduces the incidence of complications, shortens hospitalization time, and enhances psychological well-being and quality of life. These findings demonstrate its significant clinical application value and potential for broader implementation.