Incidence and influencing factors of post-traumatic stress symptoms in patients after surgery for acute intestinal obstruction

Abstract

BACKGROUND

Acute intestinal obstruction (AIO) is an urgent surgical emergency characterized by a high physiological and psychological burden. Post-traumatic stress symptoms (PTSS) are now widely recognized as a common sequela of acute illness and emergency surgery in critically ill patients, with incidence rates of 20%-30% reported in intensive care unit populations; however, systematic studies of early postoperative PTSS following emergency abdominal surgery for AIO remain scarce. Risk factors for PTSS in this surgical population, including trauma severity, postoperative pain, complications, and social support, are not well characterized and warrant focused epidemiological investigation.

AIM

To explore the incidence and predictors of PTSS in patients with AIO after surgery.

METHODS

A total of 311 patients who underwent surgical treatment for AIO in the general surgery department of our hospital between January 2021 and July 2025 were enrolled. Clinical data were collected retrospectively from medical records; at three months postoperatively, psychological scales [Post-Traumatic Stress Disorder Checklist-Civilian Version (PCL-C), Self-rating Anxiety Scale, Self-rating Depression Scale, Social Support Rating Scale, and World Health Organization Quality of Life Brief Version] were administered via outpatient interview or telephone follow-up as part of the routine post-discharge follow-up program. Demographic, disease- and surgery-related, perioperative pain, and postoperative data were collected. Univariate and multivariate logistic regression analyses were performed to identify factors influencing PTSS.

RESULTS

Of the 311 patients, 89 (28.6%) were diagnosed with PTSS (PCL-C score ≥ 38) and 37 (11.9%) had a PCL-C score ≥ 50. Multivariate logistic regression analysis demonstrated that strangulated intestinal obstruction [odds ratio (OR) = 2.348, 95% confidence interval (CI): 1.287-4.285; P = 0.005], open surgery (OR = 2.612, 95%CI: 1.426-4.785; P = 0.002), stoma formation (OR = 2.184, 95%CI: 1.156-4.125; P = 0.016), postoperative complications (OR = 2.876, 95%CI: 1.582-5.231; P = 0.001), and the 24-hour postoperative pain score during activity (OR = 1.386, 95%CI: 1.132-1.697; P = 0.002) were independent risk factors associated with PTSS. The area under the curve of the prediction model was 0.782 (95%CI: 0.728-0.836), with a sensitivity and specificity of 74.2%, and 75.7%, respectively.

CONCLUSION

The prevalence of PTSS in patients after surgery for AIO is 28.6%. Strangulated bowel obstruction, open surgery, stoma creation, postoperative complications, and postoperative pain are independently associated with PTSS. Clinical practice should focus on postoperative mental health monitoring, with provision for early and targeted interventions in high-risk patients.

Key Words: Acute intestinal obstruction; Post-traumatic stress symptoms; Risk factors; Logistic regression analysis

Core Tip: Post-traumatic stress symptoms occurred in 28.6% of patients following surgery for acute intestinal obstruction, with 11.9% meeting the criteria for probable post-traumatic stress disorder. Multivariate logistic regression identified five independent risk factors: Strangulated obstruction, open surgical approach, stoma formation, postoperative complications, and higher 24-hour postoperative pain scores during activity. A predictive model incorporating these factors achieved an area under the curve of 0.782, with a sensitivity and specificity of 74.2% and 75.7%, respectively. These findings highlight the substantial psychological burden of emergency bowel surgery and support routine postoperative mental health screening with early targeted interventions for high-risk patients to improve recovery outcomes.

INTRODUCTION

Acute intestinal obstruction (AIO) is a common acute abdomen emergency in general surgery, characterized by abrupt onset and rapid progression, and it may be lethal without timely intervention[1]. Epidemiological data indicate that acute intestinal obstruction accounts for 15%-20% of emergency general surgical procedures, with a mortality rate estimated at 5%-10%[2]. In patients with AIO, surgical treatment is the mainstay of management, as strangulated bowel or complete obstruction requires surgery, and conservative management may also fail[3]. However, surgery for AIO often has emergency characteristics, causes massive trauma and various postoperative complications, and imposes great physiological and psychological stress on patients.

Post-traumatic stress disorder (PTSD) is a psychological disorder that develops after experiencing traumatic events and is mainly manifested as symptom clusters, namely traumatic re-experiencing, avoidance behavior, and hyperarousal[4]. More recent studies have found that acute illness and surgery can also be considered trauma that leads to PTSD or post-traumatic stress symptoms (PTSS)[5]. Surgery-related PTSS not only places an emotional burden on patients but can also cascade into a range of adverse downstream consequences, including prolonged postoperative recovery, impaired health-related quality of life, and increased utilization of medical resources[6,7]. The incidence of PTSS in intensive care unit patients has been reported to be as high as 20%-30%[8], and it may even exceed this threshold in emergency surgical patients[9].

To date, studies of postoperative PTSS have been conducted only in patients following cardiac surgery, trauma surgery, and organ transplantation[9,10]. These studies suggest that factors associated with the development of PTSS after surgical trauma include the degree of surgical trauma, postoperative pain, postoperative complications, and social support[11]. Importantly, however, studies of PTSS in patients following surgery for AIO are scarce, and little is known about its prevalence and associated risk factors. AIO is characterized by life-threatening conditions, compels patients to undergo emergency surgery, and usually involves a complicated postoperative recovery course, theoretically conferring a relatively high risk of PTSS; nevertheless, systematic epidemiological investigations and risk factor analyses remain scarce[12]. Clarifying the occurrence of PTSS and its influencing factors in patients after AIO surgery is of great clinical significance for the early identification of high-risk groups and the implementation of targeted interventions to improve prognosis[13]. Therefore, this study conducted a retrospective investigation to explore the incidence and influencing factors of PTSS in patients undergoing AIO surgery, thereby providing a scientific basis for clinical prevention and treatment.

MATERIALS AND METHODS

Study subjects

A retrospective study design was adopted. Patients who underwent surgical treatment for AIO in the general surgery department of our hospital between January 2021 and July 2025 and who met the inclusion and exclusion criteria were enrolled as study subjects. Clinical data were collected from the hospital electronic medical record system. Scale assessments [PTSD Checklist-Civilian Version (PCL-C), Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS), Social Support Rating Scale (SSRS), and World Health Organization Quality of Life Brief Version (WHOQOL-BREF)] performed at 3 months postoperatively via face-to-face outpatient interview or telephone follow-up were also extracted from the medical records as part of the documented follow-up process. A total of 311 patients with complete data were included (see Figure 1 for the patient flow diagram). This study was approved by the hospital ethics committee.

Figure 1 Patient flow diagram. Flow diagram of patient selection, showing the number of patients who underwent surgery for acute intestinal obstruction between January 2021 and July 2025, those excluded according to the exclusion criteria (including patients who died before the 3-month assessment or were lost to follow-up), and the 311 patients with complete data included in the final analysis. PCL-C: Post-Traumatic Stress Disorder Checklist-Civilian Version; SAS: Self-rating Anxiety Scale; SDS: Self-rating Depression Scale; SSRS: Social Support Rating Scale; WHOQOL-BREF: World Health Organization Quality of Life Brief Version.

Inclusion criteria: (1) Age ≥ 18 years; (2) Met the diagnostic criteria for AIO and received emergency or limited-term surgical treatment; (3) Postoperative survival time ≥ 3 months; (4) Complete clinical data and able to complete follow-up assessment; (5) Clear consciousness, with normal communication ability; and (6) Complete records in the medical record system, including key data such as perioperative pain scores.

Exclusion criteria: (1) History of mental illness or long-term use of psychiatric medications; (2) Pre-existing PTSD or other anxiety and depression disorders before surgery; (3) Concomitant severe heart, liver, kidney, or other vital organ failure; (4) Terminal malignant tumor; (5) Cognitive dysfunction or severe hearing or visual impairment preventing cooperation with the scale assessments; and (6) Incomplete clinical data.

Data collection

Patient demographic and clinical data were collected through the hospital electronic medical record system: (1) General data, including gender, age, body mass index (BMI), education level, marital status, etc.; (2) Disease-related data, including etiology of intestinal obstruction (adhesive, incarcerated hernia, neoplastic, other), obstruction site (high small intestine, low small intestine, colon), obstruction type (simple, strangulated), time from onset to surgery, etc.; (3) Surgery-related data, including surgical approach (open surgery, laparoscopic surgery), surgical duration, intraoperative blood loss, intestinal resection status, stoma status, etc.; and (4) Postoperative data, including postoperative complications (pulmonary infection, incision infection, abdominal infection, anastomotic leakage, intestinal fistula, etc.), repeat surgery status, etc.

PTSS assessment: The PCL-C was used for assessment. The PCL-C was developed by the United States National Center for PTSD and has been widely used to assess stress symptoms after various traumatic events, with good reliability and validity. The Chinese version of the PCL-C has demonstrated satisfactory reliability and validity, with a Cronbach’s coefficient of 0.92 reported in a Chinese population[14]. The scale contains 17 items corresponding to three symptom clusters of PTSD in DSM-IV: Re-experiencing symptoms (items 1-5), avoidance/numbing symptoms (items 6-12), and hyperarousal symptoms (items 13-17). A 5-point Likert scale was used, with 1 point = “not at all”, 2 points = “a little bit”, 3 points = “moderately”, 4 points = “quite a bit”, and 5 points = “extremely”, yielding a total score range of 17-85 points. A PCL-C total score ≥ 38 points was defined as significant PTSS (PTSS positive), and a total score ≥ 50 points suggested possible PTSD. The assessment was conducted 3 months postoperatively through face-to-face outpatient interviews or telephone follow-up.

Perioperative pain assessment: The Numerical Rating Scale or Visual Analogue Scale (VAS) was used to assess perioperative pain intensity. Pain score data were collected within 24 hours postoperatively, at 48 hours postoperatively, and at 72 hours postoperatively. Pain scores ranged from 0-10 points, with 0 indicating no pain and 10 indicating the most severe pain. Assessment time points included pain scores at rest and during activity.

Psychological state assessment: The SAS and SDS were used to assess patients' postoperative psychological state.

The SAS was developed by Zung in 1971 and contains 20 items with 4-level scoring (1 point = “none or a little of the time”, 2 points = “some of the time”, 3 points = “a good part of the time”, 4 points = “most or all of the time”), with 5 items reverse scored. The sum of the 20 item scores gives the raw score, which is multiplied by 1.25 and rounded to an integer to obtain the standard score, with a total score range of 25-100 points. The scoring criteria were: A standard score < 50 points is normal, 50-59 points indicates mild anxiety, 60-69 points indicates moderate anxiety, and ≥ 70 points indicates severe anxiety. This scale has good reliability and validity and is widely used both domestically and internationally.

The SDS was developed by Zung in 1965 and contains 20 items with 4-level scoring (1 point = “none or a little of the time”, 2 points = “some of the time”, 3 points = ”a good part of the time”, 4 points = “most or all of the time”), with 10 items reverse scored. The scoring method is the same as that of the SAS: The raw score is multiplied by 1.25 and rounded to an integer to obtain the standard score, with a total score range of 25-100 points. The scoring criteria were: A standard score < 53 points is normal, 53-62 points indicates mild depression, 63-72 points indicates moderate depression, and ≥ 73 points indicates severe depression (referring to Zung’s original scoring criteria and Chinese norms). This scale is one of the scales recommended by the United States Department of Education, Health and Welfare for psychopharmacological research. Because of its ease of use and its ability to directly reflect subjective feelings of depression, it has been widely used in clinical screening and research. The assessment time was 3 months postoperatively, and the assessment method was the same as that of the PCL-C.

Social support assessment: The SSRS was used to assess patients’ social support status. This scale was developed by Xiao SL and includes three dimensions: Objective support (3 items), subjective support (4 items), and support utilization (3 items), with a total of 10 items and a total score range of 12-66 points. Higher scores indicate better social support. This scale has good reliability and validity and is widely used domestically. The assessment time was 3 months postoperatively, and the assessment method was the same as that of the PCL-C.

Quality of life assessment: The WHOQOL-BREF was used to assess patients’ quality of life at 3 months postoperatively. This scale was developed by the World Health Organization and includes four domains: Physical, psychological, social relationships, and environment, with a total of 26 items using 5-level scoring. Domain scores are converted to 0-100 points, with higher scores indicating better quality of life. The Chinese version of the WHOQOL-BREF has been listed as a Chinese health industry standard (WS/T119-1999) and has good reliability and validity. The assessment time was 3 months postoperatively, and the assessment method was the same as that of the PCL-C.

Statistical analysis

Statistics were computed using SPSS 26.0 software. Normally distributed continuous data, expressed as the mean ± SD, were analyzed using the independent-samples t-test; non-normally distributed data, reported as median (P25, P75), were analyzed using the Mann-Whitney U test. Categorical data, expressed as n (%), were compared using the χ² test or Fisher's exact test. Ordinal and continuous variables were entered on their original scale, whereas unordered categorical variables (etiology of intestinal obstruction and obstruction site) were entered as dummy variables (reference categories: Adhesive and high small intestine, respectively). This univariate analysis was followed by multivariate logistic regression with forward stepwise selection (forward: LR) for factors associated with PTSS (P < 0.10). Model performance was assessed using receiver operating characteristic (ROC) curve analysis [area under the curve (AUC) with 95% confidence interval (CI)]. The Youden index was used to determine the optimal cutoff. P < 0.05 was considered statistically significant.

RESULTS

General situation

This study enrolled 311 patients who underwent surgery for AIO, comprising 172 males (55.3%) and 139 females (44.7%), with a mean age of 58.4 ± 14.2 years. Among the 311 cases at the 3-month postoperative follow-up, the PCL-C score was ≥ 38 points in 89 cases (28.6%), which were defined as PTSS-positive, and < 38 points in the remaining 222 cases (71.4%), which were defined as PTSS-negative. The PCL-C score was ≥ 50 points in 37 cases (11.9%).

General data comparison between PTSS-positive and -negative groups

No statistically significant differences were observed between the two groups in terms of sex, age, BMI, or marital status (P > 0.05). There were significantly more patients with junior high school education or below in the PTSS-positive group than in the PTSS-negative group (P = 0.021) (Table 1).

Table 1 Comparison of general data between the two groups, n (%).

Item	PTSS-positive group (n = 89)	PTSS-negative group (n = 222)	Test statistic	P value
Gender			χ2 = 0.312	0.576
Male	52 (58.4)	120 (54.1)
Female	37 (41.6)	102 (45.9)
Age (years, mean ± SD)	59.8 ± 13.6	57.8 ± 14.4	t = 1.134	0.258
BMI (kg/m2, mean ± SD)	23.2 ± 3.4	23.6 ± 3.2	t = -0.976	0.33
Education level			χ2 = 7.692	0.021
Junior high school and below	58 (65.2)	115 (51.8)
High school/vocational school	21 (23.6)	68 (30.6)
College and above	10 (11.2)	39 (17.6)
Marital status			χ2 = 2.148	0.143
Married	74 (83.1)	198 (89.2)
Unmarried/divorced/widowed	15 (16.9)	24 (10.8)

PTSS: Post-traumatic stress symptoms; BMI: Body mass index.

Comparison of disease- and surgery-related data between PTSS-positive and -negative groups

Compared with the PTSS-negative group, the PTSS-positive group had a higher proportion of strangulated intestinal obstruction (P = 0.003), a longer time from onset to surgery (P = 0.012), a higher proportion of open surgery (P < 0.001), a longer surgical duration (P = 0.006), and greater intraoperative blood loss (P = 0.015). In addition, the PTSS-positive group had a significantly higher rate of intestinal resection than the PTSS-negative group (51.7% vs 33.3%, P = 0.001). The etiology of intestinal obstruction and obstruction site did not differ significantly between the two groups (P > 0.05) (Table 2).

Table 2 Comparison of disease- and surgery-related data between the two groups, n (%).

Item	PTSS-positive group (n = 89)	PTSS-negative group (n = 222)	Test statistic	P value
Etiology of intestinal obstruction			χ2 = 4.216	0.239
Adhesive	42 (47.2)	128 (57.7)
Incarcerated hernia	28 (31.5)	58 (26.1)
Neoplastic	14 (15.7)	26 (11.7)
Other	5 (5.6)	10 (4.5)
Obstruction site			χ2 = 2.487	0.288
High small intestine	23 (25.8)	48 (21.6)
Low small intestine	38 (42.7)	112 (50.5)
Colon	28 (31.5)	62 (27.9)
Obstruction type			χ2 = 8.924	0.003
Simple	51 (57.3)	168 (75.7)
Strangulated	38 (42.7)	54 (24.3)
Time from onset to surgery [hours, median (P25, P75)]	18 (12, 28)	14 (10, 22)	Z = -2.513	0.012
Surgical approach			χ2 = 18.647	< 0.001
Laparoscopic	24 (27.0)	126 (56.8)
Open	65 (73.0)	96 (43.2)
Surgical duration [minutes, median (P25, P75)]	165 (125, 215)	140 (105, 185)	Z = -2.748	0.006
Intraoperative blood loss [mL, median (P25, P75)]	120 (80, 200)	100 (60, 150)	Z = -2.437	0.015
Intestinal resection			χ2 = 11.324	0.001
Yes	46 (51.7)	74 (33.3)
No	43 (48.3)	148 (66.7)
Stoma			χ2 = 22.186	< 0.001
Yes	35 (39.3)	38 (17.1)
No	54 (60.7)	184 (82.9)

PTSS: Post-traumatic stress symptoms.

Postoperative data between PTSS-positive and -negative groups

The rates of postoperative complications (P < 0.001) and repeat surgery (P = 0.002) were higher in the PTSS-positive group compared with the PTSS-negative group (Table 3).

Table 3 Comparison of postoperative data between the two groups, n (%).

Item	PTSS-positive group (n = 89)	PTSS-negative group (n = 222)	Test statistic	P value
Postoperative complications			χ2 = 21.438	< 0.001
Yes	42 (47.2)	52 (23.4)
No	47 (52.8)	170 (76.6)
Complication type1
Pulmonary infection	18 (20.2)	22 (9.9)
Incision infection	12 (13.5)	15 (6.8)
Abdominal infection	8 (9.0)	10 (4.5)
Anastomotic leakage	6 (6.7)	4 (1.8)
Intestinal fistula	5 (5.6)	3 (1.4)
Other	3 (3.4)	8 (3.6)
Repeat surgery			χ2 = 9.876	0.002
Yes	16 (18.0)	15 (6.8)
No	73 (82.0)	207 (93.2)

¹Some patients had multiple complications.

PTSS: Post-traumatic stress symptoms.

Comparison of perioperative pain scores between PTSS-positive and -negative groups

Pain scores at rest and during activity at 24, 48, and 72 hours postoperatively were higher in the PTSS-positive group than in the PTSS-negative group (P < 0.001) (Table 4).

Table 4 Comparison of perioperative pain scores between the two groups [median (P25, P75)].

Item	PTSS-positive group (n = 89)	PTSS-negative group (n = 222)	Z value	P value
24-hour postoperative pain at rest	6 (5, 7)	5 (4, 6)	-5.824	< 0.001
24-hour postoperative pain during activity	7 (6, 8)	6 (5, 7)	-6.147	< 0.001
48-hour postoperative pain at rest	5 (4, 6)	4 (3, 5)	-5.392	< 0.001
48-hour postoperative pain during activity	6 (5, 7)	5 (4, 6)	-5.678	< 0.001
72-hour postoperative pain at rest	4 (3, 5)	3 (2, 4)	-5.156	< 0.001
72-hour postoperative pain during activity	5 (4, 6)	4 (3, 5)	-5.431	< 0.001

PTSS: Post-traumatic stress symptoms.

Comparison of psychological state, social support, and quality of life between PTSS-positive and -negative groups

SAS scores (P < 0.001) and SDS scores (P < 0.001) were higher in the PTSS-positive group than in the PTSS-negative group, whereas SSRS scores were lower in the PTSS-positive group (P < 0.001). There were statistically significant differences in all WHOQOL-BREF domain scores between the PTSS-positive and PTSS-negative groups (P < 0.001) (Table 5). The distribution of anxiety and depression severity levels differed significantly between the two groups, as shown in Table 6 (P < 0.001).

Table 5 Comparison of psychological state, social support, and quality of life between two the groups (mean ± SD).

Item	PTSS-positive group (n = 89)	PTSS-negative group (n = 222)	t value	P value
PCL-C total score	46.8 ± 7.2	28.3 ± 5.6	23.564	< 0.001
Re-experiencing symptoms	15.2 ± 3.1	8.4 ± 2.2	20.318	< 0.001
Avoidance/numbing symptoms	18.6 ± 3.8	11.2 ± 2.8	18.127	< 0.001
Hyperarousal symptoms	13.0 ± 2.6	8.7 ± 2.1	14.832	< 0.001
SAS score	58.4 ± 8.6	42.3 ± 7.2	16.547	< 0.001
SDS score	60.2 ± 9.4	44.1 ± 8.3	15.126	< 0.001
SSRS total score	32.8 ± 6.4	40.5 ± 7.1	-9.187	< 0.001
Objective support	7.2 ± 2.1	9.4 ± 2.3	-8.124	< 0.001
Subjective support	16.3 ± 3.4	20.6 ± 3.8	-9.648	< 0.001
Support utilization	9.3 ± 2.2	10.5 ± 2.1	-4.562	< 0.001
WHOQOL-BREF
Physical domain	52.3 ± 10.2	68.4 ± 9.6	-13.572	< 0.001
Psychological domain	48.6 ± 11.4	65.2 ± 10.8	-12.481	< 0.001
Social relationships domain	54.7 ± 12.3	67.9 ± 11.2	-9.328	< 0.001
Environment domain	50.8 ± 10.6	64.3 ± 9.8	-11.024	< 0.001

PTSS: Post-traumatic stress symptoms; PCL-C: Post-Traumatic Stress Disorder Checklist-Civilian Version; SAS: Self-rating Anxiety Scale; SDS: Self-rating Depression Scale; SSRS: Social Support Rating Scale; WHOQOL-BREF: World Health Organization Quality of Life Brief Version.

Table 6 Comparison of anxiety and depression severity grades between the two groups, n (%).

Item	PTSS-positive group (n = 89)	PTSS-negative group (n = 222)	Test statistic	P value
Anxiety level			χ2 = 82.147	< 0.001
Normal (< 50 points)	12 (13.5)	152 (68.5)
Mild (50-59 points)	38 (42.7)	58 (26.1)
Moderate (60-69 points)	31 (34.8)	11 (5.0)
Severe (≥ 70 points)	8 (9.0)	1 (0.5)
Depression level			χ2 = 91.364	< 0.001
Normal (< 53 points)	8 (9.0)	138 (62.2)
Mild (53-62 points)	42 (47.2)	72 (32.4)
Moderate (63-72 points)	32 (36.0)	11 (5.0)
Severe (≥ 73 points)	7 (7.9)	1 (0.5)

PTSS: Post-traumatic stress symptoms.

Identification of influencing factors of PTSS by univariate logistic regression analysis

The occurrence of PTSS was set as the dependent variable (coding: PTSS positive = 1, PTSS negative = 0), and general factors, disease- and surgery-related factors, postoperative factors, and perioperative pain scores were used as independent variables for univariate logistic regression analysis. Education level (P = 0.027), obstruction type (P = 0.004), time from onset to surgery (P = 0.018), surgical approach (P < 0.001), surgical duration (P = 0.009), intraoperative blood loss (P = 0.021), intestinal resection (P = 0.002), stoma (P < 0.001), postoperative complications (P < 0.001), repeat surgery (P = 0.003), and the 24-hour postoperative pain score during activity (P < 0.001) were found to be associated with PTSS occurrence in the univariate analysis (P < 0.10) and were therefore included in the multivariate logistic regression analysis (Table 7).

Table 7 Univariate logistic regression analysis of influencing factors of post-traumatic stress symptoms.

Variable	Coding	β	SE	Wald χ2	P value	OR	95%CI
Gender	Male = 0, female = 1	0.179	0.236	0.575	0.448	1.196	0.752-1.903
Age	Continuous variable	0.01	0.009	1.284	0.257	1.01	0.993-1.028
BMI	Continuous variable	-0.038	0.039	0.952	0.329	0.963	0.892-1.039
Education level	Junior high and below = 1, high school/vocational = 2, college and above = 3	-0.385	0.174	4.897	0.027	0.68	0.484-0.956
Marital status	Married = 0, unmarried/divorced/widowed = 1	0.506	0.347	2.126	0.145	1.659	0.840-3.277
Etiology of intestinal obstruction	Adhesive = 1, incarcerated hernia = 2, neoplastic = 3, other = 4	0.126	0.123	1.051	0.305	1.134	0.891-1.443
Obstruction site	High small intestine = 1, low small intestine = 2, colon = 3	0.145	0.127	1.303	0.254	1.156	0.901-1.483
Obstruction type	Simple = 0, strangulated = 1	0.849	0.296	8.227	0.004	2.337	1.308-4.176
Time from onset to surgery	Continuous variable	0.018	0.008	5.624	0.018	1.018	1.003-1.034
Surgical approach	Laparoscopic = 0, open = 1	1.234	0.287	18.473	< 0.001	3.435	1.958-6.027
Surgical duration	Continuous variable	0.005	0.002	6.854	0.009	1.005	1.001-1.009
Intraoperative blood loss	Continuous variable	0.003	0.001	5.342	0.021	1.003	1.000-1.005
Intestinal resection	No = 0, yes = 1	0.768	0.254	9.154	0.002	2.155	1.310-3.547
Stoma	No = 0, yes = 1	1.082	0.279	15.047	< 0.001	2.95	1.709-5.094
Postoperative complications	No = 0, yes = 1	1.082	0.262	17.049	< 0.001	2.95	1.766-4.929
Repeat surgery	No = 0, yes = 1	0.969	0.326	8.83	0.003	2.635	1.392-4.989
24-hour postoperative pain during activity	Continuous variable	0.412	0.098	17.632	< 0.001	1.51	1.246-1.830

BMI: Body mass index; OR: Odds ratio; CI: Confidence interval.

Multivariate logistic regression analysis of influencing factors of PTSS

In the multivariate logistic regression analysis, all variables with P < 0.10 in the univariate analysis were included: Education level (dichotomized), obstruction type, time from onset to surgery (days), surgical approach, surgical duration (minutes), intraoperative blood loss (mL), intestinal resection or stoma performed during the initial surgery, presence of postoperative complications, repeat surgery after the initial operation due to symptom recurrence (some patients returned without bowel obstruction but had complaints such as abdominal pain suggestive of a subtotal obstructive syndrome), and the 24-hour postoperative VAS score during activity. Screening was performed using the stepwise method (forward: LR). Strangulated intestinal obstruction [odds ratio (OR) = 2.348, 95%CI: 1.287-4.285, P = 0.005], open surgery (OR = 2.612, 95%CI: 1.426-4.785, P = 0.002), stoma (OR = 2.184, 95%CI: 1.156-4.125, P = 0.016), postoperative complications (OR = 2.876, 95%CI: 1.582-5.231, P = 0.001), and the 24-hour postoperative pain score during activity (OR = 1.386, 95%CI: 1.132-1.697, P = 0.002) were independent risk factors for PTSS after AIO surgery (Table 8 and Figure 2).

Figure 2 Forest plot of independent risk factors for post-traumatic stress symptoms in postoperative patients with acute intestinal obstruction. Forest plot displaying odds ratios (ORs) with 95% confidence intervals for the five independent risk factors identified by multivariate logistic regression analysis. The dashed vertical line represents OR = 1.0 (no effect). All five factors—strangulated obstruction, open surgery, stoma formation, postoperative complications, and the 24-hour postoperative activity-related pain score—demonstrated statistically significant positive associations with post-traumatic stress symptoms (all P < 0.05). OR: Odds ratio; CI: Confidence interval.

Table 8 Multivariate logistic regression analysis of influencing factors of post-traumatic stress symptoms.

Variable	β	SE	Wald χ2	P value	OR	95%CI
Obstruction type (strangulated vs simple)	0.854	0.307	7.741	0.005	2.348	1.287-4.285
Surgical approach (open vs laparoscopic)	0.96	0.31	9.587	0.002	2.612	1.426-4.785
Stoma (yes vs no)	0.781	0.324	5.806	0.016	2.184	1.156-4.125
Postoperative complications (yes vs no)	1.057	0.307	11.862	0.001	2.876	1.582-5.231
24-hour postoperative pain during activity	0.326	0.104	9.847	0.002	1.386	1.132-1.697
Constant	-2.486	0.245	102.976	< 0.001	0.083

Model χ² = 78.563, P < 0.001; Hosmer-Lemeshow test χ² = 7.142, P = 0.521; Nagelkerke R² = 0.318. OR: Odds ratio; CI: Confidence interval.

ROC curve analysis of the prediction model

A multivariate logistic regression analysis was performed to establish a model for predicting PTSS. ROC curve analysis demonstrated that the AUC of this model for predicting PTSS in patients after AIO surgery was 0.782 (95%CI: 0.728-0.836, P < 0.001), with a sensitivity of 74.2% and a specificity of 75.7% (Table 9 and Figure 3).

Figure 3 Receiver operating characteristic curve for post-traumatic stress symptoms prediction model in postoperative patients with acute intestinal obstruction. Receiver operating characteristic curve illustrating the discriminatory performance of the multivariate logistic regression–based prediction model. The model achieved an area under the curve (AUC) of 0.782 [95% confidence interval (CI): 0.728-0.836], indicating moderate-to-good predictive ability. The optimal cutoff point (diamond marker), determined by maximizing the Youden index, yielded a sensitivity of 74.2% and a specificity of 75.7%. The dashed diagonal line represents the reference line (AUC = 0.500). AUC: Area under the curve; ROC: Receiver operating characteristic; CI: Confidence interval.

Table 9 Receiver operating characteristic curve analysis of the prediction model.

Item	AUC	95%CI	P value	Optimal cutoff value	Sensitivity (%)	Specificity (%)
Prediction model	0.782	0.728-0.836	< 0.001	0.298	74.2	75.7

AUC: Area under the curve; CI: Confidence interval.

DISCUSSION

The present study found that the incidence of PTSS in patients after AIO surgery was 28.6%, and PCL-C scores ≥ 50 points (suspected PTSD) were observed in 11.9% of patients. This rate is considerably higher than the prevalence reported in general surgical patients[15], but comparable to that reported in critically ill patients and emergency surgical patients[16,17]. Multiple studies have demonstrated that PTSS rates in elective surgery patients are approximately 10%-15%[18], whereas they are higher (25%-35%) in emergency surgical patients[19]. In conclusion, this study shows that, as an acute critical illness, AIO and its surgical treatment produce substantial psychological trauma, warranting greater attention from clinical medical staff.

Based on multivariate logistic regression analysis, strangulated intestinal obstruction remained an independent risk factor for PTSS. Compared with uncomplicated intestinal obstruction, it is more dangerous (with a higher risk of death and postoperative complications) because strangulation usually occurs[20]. Phenomenologically, the experience of an acute threat to life is highly consistent with a key diagnostic criterion of PTSD, namely, “exposure to actual or threatened death”[21]. Studies have demonstrated that disease severity is associated with higher rates of postoperative PTSS[22], and our results further support this observation.

While strangulated intestinal obstruction may mark the onset of PTSS, it is traditionally thought that this psychological process proceeds independently of the objective life threat experience. A plausible but as-yet-unverified mechanism is that intestinal ischemia-reperfusion injury may induce a systemic inflammatory response with increased pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-α, which modulates amygdala hyperreactivity and worsens hippocampal-dependent fear extinction. Moreover, the combination of visceral hypoxia and potent nociceptive signaling associated with strangulation likely sensitizes central stress circuits, further lowering the threshold for consolidation of a traumatic memory. Such neurobiological mechanisms provide a credible link between surgical insult and subsequent PTSS and warrant exploration in larger prospective studies.

Surgical approach is another key independent risk factor, with the risk of PTSS being 2.612 times higher in patients who underwent open surgery than in those who underwent laparoscopic surgery. This may be due to greater surgical trauma, more intense postoperative pain, and longer recovery in open surgery[23]. Minimally invasive surgical techniques are being developed that may cause less psychological trauma. Several studies have shown that laparoscopic operations are associated with less physiological assault and reduced psychological stress reactions[24]. Nevertheless, this finding is limited by complex conditions and excessive adhesions, which necessitate open surgery in a substantial proportion of patients diagnosed with AIO. Improved perioperative psychological support and tight pain control are therefore especially important for these patients.

The risk of developing PTSS is especially increased after stoma creation. A stoma affects the patient’s body image and daily life. Patients must cope with a multitude of issues, such as fecal management, social embarrassment, and self-identity crisis[25]. The literature reports that the incidence of depression and anxiety in stoma patients is much higher than in non-stoma patients[26], which is consistent with the results of this study, in which the psychological state scores of stoma patients were significantly higher than those of non-stoma patients. It should be noted that even when temporary stomas are employed, there can be long-lasting psychological effects on patients[27]. Thus, a comprehensive psychological support system and stoma care guidance should be established for stoma patients to help them adapt to their new lifestyle.

Postoperative complications are a significant predictor of PTSS (a > 2.876-fold higher risk of developing PTSS). Complications causing delays in recovery and renewed health threats may induce re-experiencing of surgical trauma[28]. Particularly severe complications, such as anastomotic leakage and abdominal infection, often necessitate surgical intervention or prolonged hospitalization; these compounding medical traumas amplify patients’ stress responses[29]. Repeat surgery was significantly more frequent in the PTSS-positive group, supporting this view. Reducing psychological trauma is an important means of preventing postoperative complications and improving physiological prognosis.

This study also identified postoperative pain as an independent risk factor. The risk of PTSS increases by 38.6% with every 1-point increase in the 24-hour postoperative pain score during activity. Pain in particular is the most potent negative experience that promotes traumatic memory[30]. Improper management of acute pain can consolidate pain memories, leading to a greater likelihood of developing PTSS[31]. Active management of pain in the early postoperative period has been reported to decrease the occurrence of chronic pain and psychological disorders[32]. A critical implication of the present study is the need to standardize perioperative analgesia protocols, encouraging a multimodal analgesia strategy to keep postoperative pain within an acceptable range.

The present study also showed that PTSS-positive patients had significantly higher scores of anxiety and depression, and lower social support levels and quality of life, than those without PTSS, implying that PTSS may exert a considerable negative effect on patients’ mental health and quality of life. This corresponds with the results of previous studies[33] showing that PTSS co-occurs with, rather than exists in isolation from, other conditions, serving as an indicator of comorbid psychopathology and functional impairment. Intervention for PTSS could target not only the symptoms but also improvements in mental health status and social functioning during recovery.

The current study also revealed that the PTSS-positive group had lower objective and subjective support scores and support utilization scores than the PTSS-negative group. Social support is a modifiable protective factor and should be monitored more carefully in clinical practice. Holistically driven perioperative nursing interventions (including preoperative psychological preparation, repeated emotional assessments throughout hospitalization, and discharge planning involving family caregivers) could provide stronger social support and thus moderate stress responses. Targeted education of family members, especially for patients with stoma formation or postoperative complications, is a feasible and inexpensive preventive approach for reducing PTSS risk in high-priority subgroups.

According to the risk factors mentioned above, the prediction model in our study showed moderate predictive efficacy (AUC = 0.782)[34], which can effectively identify high-risk PTSS patients early after surgery and guide targeted interventions. By taking into consideration patients’ obstruction type, surgical approach, presence of stoma, postoperative complications, and pain level, clinical medical staff could evaluate the risk of PTSS in individual patients and initiate early psychological screening for those at high risk[35].

Limitations of this study include: (1) Selection bias and information bias due to the retrospective study design; (2) Assessment being performed only at the 3-month postoperative time point, which did not allow for dynamic observation of PTSS changes over time; and (3) Preoperative psychological state and coping styles, which possibly affect PTSS, were not included. Prospective cohort designs, multiple time point follow-ups, and psychological intervention measures should be the focus of future investigations.

CONCLUSION

The incidence of PTSS among patients undergoing surgery for AIO is comparatively high, and strangulated intestinal obstruction, open surgery, stoma, postoperative complications, and postoperative pain are independent risk factors for PTSS. The lack of regular postoperative mental health assessments in clinical practice should be addressed by implementing early screening and targeted interventions for high-risk patients to improve prognosis and quality of life.