Impact of enhanced recovery after surgery on postoperative pain management and functional recovery in patients with colorectal cancer

Abstract

BACKGROUND

Limited evidence exists regarding the role of enhanced recovery after surgery (ERAS) protocols in optimizing pain management and functional recovery after colorectal cancer (CRC) surgery.

AIM

To evaluate the impact of ERAS protocols on postoperative pain management and functional recovery in patients undergoing CRC surgery.

METHODS

A total of 109 patients with CRC admitted to The Third Affiliated Hospital of Jinzhou Medical University between June 2021 and June 2024 were enrolled in this study. They were divided into two groups: A control group (n = 50) receiving standard perioperative care and an observation group (n = 59) managed under an ERAS protocol. Clinical outcomes, including postoperative pain intensity [assessed using the Visual Analogue Scale (VAS)], functional recovery indicators (time to first ambulation, bowel sound recovery, first anal gas discharge, and first defecation), average sleep duration on postoperative day 3, sleep quality (measured using the Pittsburgh Sleep Quality Index), length of hospitalization, quality of life (evaluated using the Short Form 36 Health Survey), and incidence of postoperative complications (e.g., surgical site infection, pulmonary infection, abdominal distension/pain, and intestinal obstruction), were systematically compared between the two groups.

RESULTS

The observation group exhibited significantly lower VAS scores at 72 hours postoperatively, shorter durations of maximum VAS scores, earlier recovery of functional indicators (time to first ambulation, bowel sound recovery, first anal gas discharge, and first defecation), and shorter hospitalization compared with the control group. Additionally, average sleep duration on postoperative day 3 was significantly longer in the observation group. Furthermore, the observation group demonstrated significantly improved sleep quality (lower Pittsburgh Sleep Quality Index scores) and higher quality of life (higher Short Form 36 Health Survey scores across all domains) than both the baseline and control groups. The incidence of total postoperative complications was also significantly lower in the observation group than in the control group.

CONCLUSION

ERAS protocols are highly effective in relieving postoperative pain, accelerating functional recovery, and improving overall clinical outcomes in patients with CRC undergoing surgery, supporting their broader clinical application.

Key Words: Enhanced recovery after surgery; Colorectal cancer; Postoperative pain management; Functional recovery; Visual analog scale

Core Tip: Colorectal cancer has a high incidence and mortality. This study evaluated the effectiveness of enhanced recovery after surgery protocols on postoperative pain management and functional recovery in patients undergoing colorectal cancer surgery, and found significant improvements in pain control, functional recovery, quality of life, length of hospitalization, and complication rates.

INTRODUCTION

Colorectal cancer (CRC) is a major global malignancy linked to genetic susceptibility and environmental risk factors, including obesity, alcohol use, tobacco use, and sedentary behavior[1,2]. Its multifactorial pathogenesis involves chronic inflammation, oxidative stress, impaired cell proliferation and differentiation, resistance to apoptosis, and metastases[3,4]. In 2020, CRC accounted for more than 1.9 million new cases and approximately 1 million deaths worldwide, underscoring the need for better preventive and therapeutic strategies[5]. Although multimodal treatments, including surgery, chemotherapy, and radiotherapy, have improved outcomes, CRC remains the second leading cause of cancer-related death globally[6]. Optimizing postoperative pain control and functional recovery is therefore critical for analgesia efficiency, recovery quality, and long-term quality of life[7,8]. Enhanced recovery after surgery (ERAS) is an evidence-based, comprehensive care protocol, ERAS that provides personalized, holistic perioperative management, thereby reducing obstacles to recovery[9]. Compared with standardized perioperative care models, ERAS protocols emphasize scientific rigor and a patient-centered approach, improving clinical outcomes by prioritizing patient experience and timely rehabilitation[10]. ERAS has shown consistent benefits in surgical oncology. Du et al[11] reported significantly faster recovery, fewer pulmonary complications, and enhanced lung function and quality of life in elderly patients after lung cancer surgery. ERAS protocols also effectively promote gastrointestinal function recovery and reduce adverse events after liver resection for hepatocellular carcinoma[12]. In elderly patients undergoing laparoscopic CRC surgery, ERAS provides pain control comparable to opioid-based regimens while reducing cognitive dysfunction risk and opioid-related toxicity[13]. Currently, evidence on ERAS-related pain control and functional recovery after CRC surgery is limited. This study evaluated the clinical benefits of ERAS in this patient group to optimize postoperative care and improve CRC surgery outcomes.

MATERIALS AND METHODS

Patient selection

Inclusion criteria: Histologically confirmed CRC[14]; presence of CRC-induced pain; age ≥ 18 years; candidate for radical oncological resection; preserved major organ function (hepatic, renal, and cardiopulmonary); complete medical records; and intact neurological and psychiatric status with normal communication ability. Exclusion criteria: History of chronic pain syndrome; long-term analgesic use; concurrent diagnosis of other malignancies; preoperative distant metastasis or local invasion of adjacent organs/tissues; comorbid cardio-cerebrovascular disease; severe hematological disorder; concurrent gastrointestinal disease; pregnancy or lactation. A total of 109 eligible patients, admitted to the Third Affiliated Hospital of Jinzhou Medical University between June 2021 and June 2024, were therefore enrolled in this study. They were assigned to a control group (n = 50) receiving standard perioperative care and an observation group (n = 59) managed under an ERAS protocol.

Intervention protocols

The control group received standard perioperative care: (1) Upon admission, the nursing staff assisted patients in completing routine preoperative assessments, as well as receiving verbal education regarding the disease, surgical procedure, and perioperative expectations. The patients also received psychological support to alleviate preoperative anxiety and emotional distress; (2) Bowel preparation was initiated 1 day before surgery; fasting for 12 hours and fluid restriction for 4 hours before surgery. An enema was administered on the evening before and on the morning of surgery. Nasogastric tube, urinary catheter, and peritoneal drain were inserted preoperatively and removed following postoperative flatus. A peritoneal drainage tube was also inserted; and (3) Postoperatively, patients were advised to remain in bed, maintaining a supine position without a pillow for 6 hours. Active and passive limb mobilization exercises were guided to prevent complications. Early ambulation was initiated on postoperative day 3. Oral intake resumed after flatus, progressing from liquid to semi-solid and regular diets. The above standard nursing care continued until hospital discharge.

The observation group received a comprehensive ERAS intervention with the following components: (1) Perioperative care: A multidisciplinary team of physicians and nurses, educated patients on surgical precautions, perioperative expectations, and potential outcomes. Patients observed a 6-hour fast and a 2-hour fluid restriction before surgery. To maintain metabolic stability, a carbohydrate-rich glucose solution was administered orally 2 hours before the fasting period. Routine mechanical bowel preparation was avoided to reduce discomfort. Intraoperatively, individualized anesthesia and active warming were used, drainage tube usage was minimized, and continuous reassurance was provided to alleviate patient anxiety. Postoperatively, oral intake began promptly after consciousness returned, starting with sips of warm water and progressing to early enteral nutrition as tolerated; (2) Rehabilitation training: A patient-specific rehabilitation plan encouraged ambulation at least four times daily, with a minimum walking distance of 60 m per session, while avoiding excessive exertion; (3) Psychological support and pain management: Ongoing communication addressed the patients’ psychological needs and provided tailored emotional support, fostering a positive recovery mindset. Preoperatively, a multimodal pain management approach was implemented: For mild pain, non-pharmacological interventions such as distraction techniques were utilized. For moderate to severe pain, analgesic medications, including oxycodone and sufentanil, were administered according to a predefined protocol, with dosages adjusted based on pain severity and patient response. On postoperative days 0-1, an epidural patient-controlled analgesia pump (bupivacaine 75 mg + morphine 2 mg in 150 mL saline) was used. Thereafter, non-steroidal anti-inflammatory drugs or opioids were administered as necessary. Non-pharmacological approaches, including cognitive-behavioral therapy, relaxation, music therapy, and acupressure, were added when appropriate; (4) Nutritional and pharmacological guidance: Patients were counseled to ensure balanced nutrition to support healing. Detailed instructions were provided on each prescribed medication, including purpose, dosage, administration, potential side effects, and when to contact the medical team; and (5) Complication prevention: Surgical incisions were inspected regularly for leakage or infection. Common postoperative complications (e.g., nausea, vomiting, ileus, and urinary problems) were monitored, and gastrointestinal decompression was administered when indicated. Strict infection control was maintained through close surgeon-nurse collaboration, with immediate intervention for any complication.

Data collection and outcome measures

(1) Pain intensity: Postoperative pain was assessed 72 hours after surgery using the Visual Analogue Scale (VAS)[15], ranging from 0 (pain-free) to 10 (most intense pain), with higher scores indicating greater pain severity. The duration of peak VAS score was also recorded to evaluate sustained maximal pain; (2) Functional recovery: Postoperative recovery indicators included time to first ambulation, bowel sound recovery, first anal gas discharge, and first defecation; (3) Sleep quality and hospitalization: The average sleep duration on postoperative day 3 was recorded. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI)[16] before and 3 days post-intervention. The total length of hospitalization was also documented; (4) Quality of life: Quality of life was assessed before and after the intervention using the Short Form 36 Health Survey (SF-36)[17], which covers eight domains: General health, health status, mental health, physical pain, physical function, vitality, social function, and role limitations due to emotional problems. Scores range from 0 to 100, with higher scores reflecting a better quality of life; and (5) Complications: Postoperative complications, including surgical site infections, pulmonary infections, abdominal distension/pain, and ileus, were recorded in both groups.

Statistical analysis

Continuous variables are expressed as mean ± SD. Between-group comparisons were analyzed using independent samples t-tests, whereas within-group (pre-intervention vs post-intervention) comparisons were assessed using paired t-tests. Categorical variables are expressed as frequencies and percentages and compared using the χ² test. All statistical analyses were performed using SPSS version 22.0 or GraphPad Prism 6. A P value < 0.05 was considered statistically significant.

RESULTS

General data of the two groups

A detailed flowchart for patient selection can be found in Figure 1. Comprehensive comparisons were made between the control and observation groups in terms of age, body mass index, gender, pathological classification, tumor-node-metastasis staging, and type of surgery. Statistical analysis revealed no significant inter-group differences in these parameters (P > 0.05, Table 1).

Figure 1  Flowchart of patient selection.

Table 1 General data of the two groups, mean ± SD/n (%).

Indicators	Control group (n = 50)	Observation group (n = 59)	χ2/t	P value
Age (years)	58.50 ± 6.87	55.64 ± 8.75	1.873	0.064
BMI (kg/m2)	22.52 ± 2.90	23.05 ± 2.85	0.960	0.339
Gender			0.005	0.943
Male	30 (60.00)	35 (59.32)
Female	20 (40.00)	24 (40.68)
Pathological classification			0.801	0.371
Adenocarcinoma	28 (56.00)	38 (64.41)
Mucinous adenocarcinoma	22 (44.00)	21 (35.59)
TNM staging			1.169	0.557
I	18 (36.00)	19 (32.20)
II	25 (50.00)	27 (45.76)
III	7 (14.00)	13 (22.03)
Type of surgery			1.312	0.859
Right hemicolectomy	8 (16.00)	6 (10.17)
Left hemicolectomy	7 (14.00)	7 (11.86)
Transverse colectomy	7 (14.00)	10 (16.95)
Sigmoid colectomy	6 (12.00)	6 (10.17)
Radical resection of rectal cancer	22 (44.00)	30 (50.85)

BMI: Body mass index; TNM: Tumor-node-metastasis.

Postoperative pain in the two groups

Postoperative pain levels were assessed using the VAS. The VAS in the control group was 2.52 ± 1.27 points, compared with 1.71 ± 0.98 points in the observation group. The duration of the maximum VAS score was 4.69 ± 1.53 hours in the control group and 4.03 ± 1.29 hours in the observation group. Statistical analysis showed significantly lower VAS points and shorter maximum VAS durations in the observation group than in the control group (P < 0.05, Figure 2).

Figure 2 Postoperative pain of the two groups. A: Visual Analogue Scale scores of the control and observation groups; B: Durations of maximum Visual Analogue Scale scores in the control and observation groups. ^aP < 0.05, ^bP < 0.01. VAS: Visual Analogue Scale.

Functional recovery in the two groups

Functional recovery was evaluated by recording the time to first ambulation, bowel sound recovery, anal gas discharge, and defecation. The time to first ambulation was 2.66 ± 1.10 days in the control group and 2.15 ± 0.87 days in the observation group. The time to bowel sound recovery was 2.60 ± 1.05 days in the control group and 2.22 ± 0.95 days in the observation group. The time to anal gas discharge was 4.02 ± 1.49 days in the control group and 2.80 ± 1.03 days in the observation group. The time to first defecation was 4.76 ± 1.81 days in the control group and 3.56 ± 1.45 days in the observation group. All indicators of functional recovery were significantly improved in the observation group compared with the control group (P < 0.01, Figure 3).

Figure 3 Functional recovery of the two groups. A: Time to the first ambulation of the control and observation groups; B: Time to bowel sound recovery of the control and observation groups; C: Time to anal gas discharge of the control and observation groups; D: Time to defecation of the control and observation groups. ^bP < 0.01.

Sleep duration, sleep quality, and hospitalization in the two groups

On postoperative day 3, the average sleep duration was 4.44 ± 1.21 hours in control group and 5.56 ± 1.59 hours in the observation group. Regarding PSQI scores, the pre-intervention values were 16.08 ± 3.02 points in the control group and 16.17 ± 3.18 points in the observation group. Post-intervention, PSQI scores decreased to 13.44 ± 2.87 points in the control group and 9.25 ± 1.64 points in the observation group. The average length of hospitalization was 12.38 ± 3.25 days in the control group and 8.81 ± 2.15 days in the observation group. Statistical analysis indicated that the observation group had significantly longer sleep duration on postoperative day 3 compared with the control group (P < 0.01), significantly lower PSQI scores post-intervention compared with both its baseline and the control group (P < 0.01), and significantly shorter hospitalization (P < 0.01). Detailed data are graphically presented in Figure 4.

Figure 4 Sleep duration, sleep quality and hospital stay of the two groups. A: Average sleep duration on postoperative day 3 of the control and observation groups; B: Pittsburgh Sleep Quality Index scores of the control and observation groups before and after the intervention; C: Lengths of hospital stay of the control and observation groups. ^aP < 0.05, ^bP < 0.01. PSQI: Pittsburgh Sleep Quality Index.

Quality of life in the two groups

The quality of life was assessed using the SF-36. The general health scores were 58.62 ± 6.89 points in the control group and 80.22 ± 7.46 points in the observation group. The health status scores were 52.50 ± 8.11 points in the control group and 76.49 ± 9.58 points in the observation group. The mental health scores were 43.40 ± 7.34 points in the control group and 61.49 ± 7.78 points in the observation group. The physical pain scores were 66.96 ± 6.69 points in the control group and 78.49 ± 7.58 points in the observation group. The physical function scores were 56.34 ± 5.92 points in the control group and 69.95 ± 8.27 points in the observation group. The vitality scores were 53.00 ± 7.70 points in the control group and 78.34 ± 9.75 points in the observation group. Social functioning scores were 58.12 ± 7.74 points in the control group and 79.14 ± 7.60 points in the observation group. Statistical analysis demonstrated that SF-36 scores in all domains were significantly higher in the observation group than in the control group (P < 0.05, Figure 5).

Figure 5 Quality of life of the two groups. A: General health scores of the control and observation groups; B: Health status scores of the control and observation groups; C: Mental health scores of the control and observation groups; D: Bodily pain scores of the control and observation groups; E: Physical function scores of the control and observation groups; F: Vitality scores of the control and observation groups; G: Social function scores of the control and observation groups. ^bP < 0.01.

Complications of the two groups

The overall incidence of complications, including surgical site infection, pulmonary infection, abdominal distension/pain, and ileus, was significantly lower in the observation group than in the control group (P < 0.01, Table 2).

Table 2 Complications of the two groups, n (%).

Complications	Control group (n = 50)	Observation group (n = 59)	χ2	P value
Surgical site infections	1 (2.00)	0 (0.00)
Pulmonary infections	2 (4.00)	0 (0.00)
Abdominal distension/pain	3 (6.00)	1 (1.69)
Ileus	5 (10.00)	2 (3.39)
Total	11 (22.00)	3 (5.08)	6.918	0.009

DISCUSSION

Inadequate postoperative pain control in patients with CRC can impede functional recovery, foster chronic pain syndromes, and prolong hospitalization. Implementing ERAS protocols, which optimize analgesia and prevent postoperative complications, can significantly reduce pain levels and minimize the risk of adverse events, thereby facilitating patient recovery[18]. In this study, the observation group demonstrated significantly lower VAS scores and shorter maximum VAS than the control group, indicating superior analgesic efficacy with ERAS for patients undergoing radical resection for CRC compared with standard care. This benefit likely reflects comprehensive ERAS pain control: Rigorous monitoring, pain severity-based individualized analgesic dosing, and strong psychological support, which mitigates pain while enhancing patient adherence. Similarly, Cao et al[19] reported that ERAS intervention significantly reduced VAS scores in patients with CRC after laparoscopic radical resection and attenuated early postoperative inflammation, consistent with our findings.

Regarding functional recovery, ERAS patients achieved significantly earlier ambulation, faster bowel sound recovery, and accelerated anal gas discharge and defecation, suggesting accelerated postoperative recovery. Wang et al[20] similarly observed earlier first oral intake, anal exhaust, defecation, and bowel sound recovery after radical gastrectomy under ERAS protocols, along with significant pain alleviation and better quality of life. Additionally, our study demonstrated that the ERAS protocols increased the average sleep duration on postoperative day 3, lowered PSQI scores, and shortened hospitalization duration. These benefits may be attributed to standardized perioperative management and individualized care, rehabilitation training, psychological support, multimodal analgesia, dietary and medication guidance, and proactive complication prevention, which collectively enhance care quality while expediting recovery[21]. In a report on ERAS applications in patients with esophageal cancer, the ERAS protocol substantially improved patients’ sleep and quality of life while alleviating anxiety[22], supporting our findings. Improved sleep quality after CRC surgery accelerates recovery and benefits psychological well-being and overall quality of life[23].

Furthermore, the observation group scored significantly higher across all SF-36 domains, indicating that ERAS improves the quality of life after radical CRC resection. Consistent with our findings, Wu et al[24] reported that ERAS in elderly patients undergoing colon cancer surgery significantly improved Gastrointestinal Quality of Life Index scores and treatment satisfaction. Our study also showed a lower overall incidence of complications, including surgical site infection, pulmonary infection, abdominal distension/pain, and ileus, in patients under ERAS intervention, underscoring its superior clinical safety profile. In a study on the application of ERAS in patients undergoing colorectal surgery by Song et al[25], ERAS was found to be more advantageous in reducing postoperative complications, such as anastomotic leakage, wound infection, and intestinal obstruction, compared with conventional nursing, findings that align with our current research.

Several limitations warrant attention. First, this single-center study may limit generalizability; multicenter investigations would improve external validity. Second, the retrospective design introduces inherent selection bias due to non-randomized allocation, suggesting the need for randomized controlled trials. Third, the absence of long-term outcome assessments (e.g., chronic pain and recurrence rates) limits the assessment of sustained ERAS benefits; extended follow-up is required for deeper insights. Future work will be directed toward the development of these identified areas.

CONCLUSION

In summary, ERAS interventions optimize postoperative pain control in patients with CRC, significantly alleviate pain, accelerate functional recovery, improve sleep quality and overall quality of life, shorten hospitalization, and reduce the incidence of total postoperative complications.