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*Correspondence: Yan Du,
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Surgeries for gastrointestinal tumors frequently result in considerable postoperative complications, such as surgical site infections (SSIs) and impaired nutritional parameters. This study focuses on the role of Early Postoperative Enteral Nutrition (EPEN) in alleviating these difficulties.
This retrospective study included 110 patients undergoing gastrointestinal tumor surgery between January 2019 and January 2023. Patients receiving EPEN were allocated to the observation group, while others received conventional care. Nutritional indices (total protein [TP], albumin [ALB], and prealbumin [PA]) were measured at baseline and on postoperative day 14. Baseline inflammatory status, including C-reactive protein (CRP), procalcitonin (PCT), white blood cell (WBC) count, and derived ratios such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII), was also assessed. Clinical outcomes included wound healing time and postoperative complications.
EPEN was associated with faster wound healing (10.32 ± 1.32 vs 13.65 ± 0.21 days; P<0.001) and a lower SSI rate (1.82% vs 17.02%; P = 0.015), with no difference in wound bleeding (5.45% vs 9.09%; P = 0.463). At day 14, TP, ALB, and PA were higher in the EPEN group (TP 70.76 ± 4.53 g/L; ALB 39.24 ± 1.87 g/L; PA 297.45 ± 21.32 mg/L; all P<0.001 vs control). Length of stay was similar (7.82 ± 1.21 vs 7.69 ± 1.59 days; P = 0.630). Time to first flatus (33.6 ± 5.8 vs 47.1 ± 7.1 hours; P<0.001), first bowel movement (55.2 ± 6.3 vs 70.5 ± 8.2 hours; P<0.001), and patient satisfaction (8.50 ± 1.10 vs 7.20 ± 1.30; P<0.001) favored EPEN.
In this retrospective study, EPEN might be associated with improvements in nutritional indicators and clinical outcomes, including faster wound healing and reduced surgical site infections in gastrointestinal tumor patients. However, the current data do not provide sufficient evidence to conclusively determine whether the improvements are directly due to EPEN, further prospective, randomized studies are needed to confirm these associations and clarify their causal relationships.
Gastrointestinal (GI) tumors represent a significant public health concern due to their high prevalence and the complexity of their treatment (
Early postoperative enteral nutrition (EPEN) has emerged as a crucial strategy in this regard. EPEN refers to the administration of nutrients directly into the gastrointestinal tract, typically via a tube, soon after surgery (
In light of these considerations, the present study aims to rigorously examine the influence of EPEN on postoperative wound infection rates and nutritional parameters in patients undergoing surgery for GI tumors. By focusing on these parameters, the study seeks to contribute valuable insights into the optimization of postoperative care for this patient population, potentially leading to improved clinical outcomes and enhanced quality of life.
A comprehensive retrospective analysis was meticulously conducted at our institution to evaluate the impact of EPEN on surgical site infection and nutritional parameters among patients undergoing surgeries for gastrointestinal tumors. This investigation spanned a period from January 2019 to January 2023. Patients who received EPEN postoperatively were allocated to the observation group for detailed examination. Conversely, patients who did not receive EPEN post-surgery were categorized into the control group. Informed consent was obtained from all subjects. The study was approved by the hospital’s ethics committee and conducted in accordance with relevant guidelines and regulations, including the Declaration of Helsinki. All personal data were anonymized prior to analysis to ensure participant confidentiality and privacy. Perioperative antibiotic prophylaxis was standardized across both groups. All patients received prophylactic broad-spectrum antibiotics—specifically, intravenous cefuroxime (1.5 g every 8 hours)—initiated within 30 minutes before surgical incision and continued for 24 – 48 hours postoperatively. For patients with documented β-lactam allergy, intravenous clindamycin (600 mg every 8 hours) combined with gentamicin (5 mg/kg once daily) was administered.
Diagnosis: Patients diagnosed with gastrointestinal tumors, confirmed through histopathological examination.
Surgical Intervention: Patients who underwent surgical resection for their gastrointestinal tumors.
Nutritional Parameters: Patients with varied nutritional parameters at the time of surgery, as assessed by standard nutritional screening tools.
Consent: Patients who provided informed consent for participation in the retrospective analysis.
Non-GI Tumor Surgery: Patients who underwent surgeries for conditions other than gastrointestinal tumors.
Previous Enteral Nutrition: Patients who received enteral nutrition before their surgical procedures.
Concurrent Infections: Patients with preoperative infectious conditions, including but not limited to systemic infections or localized infections in the gastrointestinal tract.
Chronic Diseases Impacting Nutrition: Patients with chronic diseases that could independently influence nutritional parameters, such as uncontrolled diabetes mellitus, chronic kidney disease, or chronic liver disease.
Postoperative Complications: Patients who experienced major postoperative complications unrelated to surgical site infection or nutritional parameters, which could potentially confound the study outcomes (e.g., postoperative hemorrhage, anastomotic leak).
In the EPEN group, patients began receiving enteral nutrition through a gastroenteric feeding tube initiated between postoperative day 1 and day 3. The enteral nutrition formula used was Nuodikang by Nuodixia Pharmaceuticals Ltd., with an energy density of 1.0 kcal/mL. The volume of this formula was incrementally increased, starting at 500 mL (administered at 50 mL/hour, providing 500 kcal and 3 g nitrogen), then progressing to 1,000 mL (at 75 mL/hour, providing 1,000 kcal and 6 g nitrogen), and eventually to 1,500 mL (at 100 mL/hour, providing 1,500 kcal and 12.5 g nitrogen) over the initial days. This regimen was maintained until the 8th postoperative day. From the 4th to the 8th postoperative day, the nutritional products, quantities, and administration methods remained the same as on the third postoperative day. If the target enteral volume was not achieved, the caloric deficit was supplemented with intravenous glucose infusion to ensure adequate total energy provision.
Patients in the non-EPEN group did not receive enteral nutrition through a feeding tube in the early postoperative period. Nutritional support consisted of conventional postoperative care, which typically included delayed initiation of oral intake once gastrointestinal function recovered, and interim reliance on parenteral nutrition when necessary. This standard approach, while commonly practiced, lacks the early gastrointestinal stimulation provided by EPEN and may influence postoperative recovery parameters such as gut motility, wound healing, and nutritional parameters.
In this study, observational indicators were recorded to assess the effects of the interventions on biochemical protein indices, inflammatory status, and surgical outcomes. Serum total protein (TP), albumin (ALB), and prealbumin (PA) were measured at baseline and 14 days after treatment using fasting morning venous blood samples processed with an automated biochemistry analyzer (BC2200, Shenzhen New Industries Biomedical Engineering Co., Ltd.). Inflammatory and immune parameters, including C-reactive protein (CRP), procalcitonin (PCT), white blood cell (WBC) count, neutrophil count, lymphocyte count, and platelet count. Derived indices were calculated as neutrophil-to-lymphocyte ratio (NLR = neutrophils/lymphocytes), platelet-to-lymphocyte ratio (PLR = platelets/lymphocytes), and systemic immune-inflammation index (SII = platelets × neutrophils/lymphocytes). Hematologic parameters were measured using a fully automated hematology analyzer (XN-9000, Sysmex Corporation, Kobe, Japan), and CRP/PCT were determined by immunoturbidimetric and chemiluminescent assays, respectively. Surgical outcomes included the duration of wound healing and the incidence of postoperative SSIs.
In this study, key postoperative recovery milestones and patient tolerance were systematically collected. Recovery milestones included the time to first flatus and first bowel movement, which were measured in hours from the time of surgery. Patient satisfaction was assessed using a 10-point Likert scale, where the scores reflected overall satisfaction with postoperative care. Additionally, tolerance to prolonged nasoenteric tube feeding was monitored in the observation group, where enteral nutrition was maintained for eight consecutive postoperative days. Tolerance was evaluated based on patient-reported symptoms, such as discomfort, nausea, and gastrointestinal issues. Significant tube-related complications, including tube dislodgement, blockage, or intolerance, were recorded. Mild discomfort (e.g., nasal or pharyngeal irritation) and nausea were managed by adjusting the feeding regimen as necessary.
The statistical evaluation of the data in this study was conducted using the SPSS software, version 27.0. Initially, the data were categorized as either quantitative or categorical. To determine the distribution pattern of each dataset, normality tests were applied. For quantitative data adhering to a normal distribution, the independent sample t-tests were utilized for assessing the statistical significance between groups, and the results were expressed as mean ± standard deviation. In contrast, quantitative data that did not follow a normal distribution were represented using medians and interquartile ranges (M[P25, P75]), and inter-group comparisons were made using the Mann-Whitney U test. Regarding categorical data, these were presented as frequencies and percentages. The Chi-square (χ2) test was employed to examine the independence or associations among these variables. For correlation analysis, Pearson’s correlation coefficient was used for normally distributed quantitative data, Spearman’s rank correlation for non-normally distributed quantitative data, and Kendall’s tau for count data. The testing of hypotheses was bidirectional (two-tailed), and a p-value of less than 0.05 was established as the threshold for determining statistical significance.
Baseline demographic and clinical characteristics, inflammatory parameters, tumor types, and surgical methods for both groups are summarized in
Baseline demographic, clinical, inflammatory, and surgical characteristics of patients in the control and observation groups.
| Item | Control group (n=55) | Observation group (n=55) | P-value |
|---|---|---|---|
| Gender (Male/Female) | 30/25 | 28/27 | 0.849 |
| Age Range (years) | 40–61 | 40–62 | — |
| Mean Age (years) | 50.54 ± 4.98 | 50.79 ± 5.06 | 0.826 |
| CRP (mg/L), median [IQR] | 6.2 [3.8 – 10.5] | 6.0 [3.5 – 10.0] | 0.324 |
| WBC (×109/L), mean ± SD | 6.88 ± 1.25 | 6.79 ± 1.30 | 0.229 |
| Neutrophils (×109/L), mean ± SD | 4.35 ± 1.05 | 4.29 ± 1.02 | 0.303 |
| Lymphocytes (×109/L), mean ± SD | 1.88 ± 0.42 | 1.92 ± 0.40 | 0.593 |
| Platelets (×109/L), mean ± SD | 248 ± 52 | 242 ± 49 | 0.655 |
| NLR, median [IQR] | 2.29 [1.80 – 2.85] | 2.23 [1.76 – 2.80] | 0.413 |
| PLR, median [IQR] | 132 [110 – 155] | 126 [108 – 150] | 0.406 |
| SII (×109/L²), median [IQR] | 561 [420 – 700] | 540 [415 – 685] | 0.357 |
| PCT (ng/mL), median [IQR] | 0.06 [0.04 – 0.09] | 0.06 [0.04 – 0.08] | 0.143 |
| Tumor Types (cases) | 0.962 | ||
| - Colon Cancer | 23 | 22 | |
| - Rectal Cancer | 17 | 18 | |
| - Gastric Cancer | 12 | 13 | |
| - Others | 3 | 2 | |
| Surgical Methods (cases) | 0.682 | ||
| - Laparoscopic Surgery | 39 | 36 | |
| - Open Surgery | 16 | 19 |
The study’s results, encapsulated in
Comparison of wound healing time and postoperative complication rates between the two patient groups (n = 55).
| Group | Wound healing time (days) | Incidence of surgical site infection [n (%)] | Incidence of wound bleeding [n (%)] |
|---|---|---|---|
| Observation (n=55) | 10.32 ± 1.32 | 1 (1.82%) | 3 (5.45%) |
| Control (n=55) | 13.65 ± 0.21 | 8 (17.02%) | 5 (9.09%) |
| t/χ² | 18.477 | 5.930 | 0.539 |
| P-value | <0.001 | 0.015 | 0.463 |
The study’s findings, as summarized in
Comparison of nutritional indicators between patient groups before and after treatment (x ± s, n = 55).
| Timepoint | Group | Total protein (TP) [g/L] | Albumin (ALB) [g/L] | Prealbumin (PA) [mg/L] |
|---|---|---|---|---|
| Pre-treatment | Observation (n=55) | 51.65 ± 4.25 | 33.24 ± 0.87 | 219.65 ± 24.72 |
| Control (n=55) | 51.81 ± 4.59 | 33.35 ± 0.76 | 219.76 ± 24.51 | |
| t-value | 0.190 | 0.706 | 0.023 | |
| p-value | 0.850 | 0.482 | 0.981 | |
| Post-treatment (14d) | Observation (n=55) | 70.76 ± 4.53* | 39.24 ± 1.87* | 297.45 ± 21.32* |
| Control (n=55) | 55.65 ± 5.34* | 32.95 ± 1.54 | 223.61 ± 23.54 | |
| t-value | 16.002 | 19.256 | 17.242 | |
| p-value | <0.001 | <0.001 | <0.001 |
*Indicates a statistically significant difference compared to pre-treatment values within the same group (P < 0.05).
In terms of hospitalization and postoperative recovery milestones, no statistically significant difference was observed in the mean length of stay between the control group (7.69 ± 1.59 days) and the observation group (7.82 ± 1.21 days; P = 0.630). The observation group demonstrated a shorter mean time to first flatus (33.6 ± 5.8 hours) compared with the control group (47.1 ± 7.1 hours; P < 0.001). Similarly, the mean time to first bowel movement was shorter in the observation group (55.2 ± 6.3 hours) than in the control group (70.5 ± 8.2 hours; P < 0.001). The patient satisfaction score was higher in the observation group (8.50 ± 1.10) than in the control group (7.20 ± 1.30; P < 0.001) (
Comparison of length of stay, recovery milestones, and patient satisfaction between the two groups.
| Outcome measure | Control group (n=55) | Observation group (n=55) | P-value |
|---|---|---|---|
| Length of Stay (days) | 7.69 ± 1.59 | 7.82 ± 1.21 | 0.630 |
| First Flatus (hours) | 47.1 ± 7.1 | 33.6 ± 5.8 | < 0.001 |
| First Bowel Movement (hours) | 70.5 ± 8.2 | 55.2 ± 6.3 | < 0.001 |
| Patient Satisfaction (1 – 10 scale) | 7.20 ± 1.30 | 8.50 ± 1.10 | < 0.001 |
In the EPEN group, nasoenteric tube feeding was maintained for eight consecutive postoperative days. Tolerance was generally high, with no patients discontinuing enteral nutrition prematurely due to tube-related intolerance. Mild discomfort, such as transient nasal or pharyngeal irritation, occurred in 7 patients (12.7%) and resolved spontaneously without intervention. Minor nausea was observed in 2 patients (3.6%) during the early feeding period and was managed by temporarily reducing the infusion rate. No cases of tube dislodgement, blockage, or significant gastrointestinal intolerance (e.g., persistent vomiting, severe diarrhea) were recorded. All patients in the EPEN group completed the planned enteral nutrition regimen via the feeding tube.
The interplay between nutritional parameters and surgical outcomes in patients undergoing surgery for gastrointestinal tumors is a complex and critical aspect of postoperative care. The influence of EPEN on surgical site infection and nutritional parameters, as investigated in our study, is grounded in the growing recognition of nutrition as a pivotal factor in patient recovery (
Our study’s results shed light on the significant impact of EPEN on postoperative recovery in patients with gastrointestinal tumors, highlighting faster wound healing and reduced complication rates in the observation group compared to the control group. The underlying mechanisms of these observed benefits appear to be deeply intertwined with the physiological responses to surgery and the role of nutrition in postoperative care. The notable improvement in wound healing times in the observation group receiving EPEN can be attributed to the direct nutritional support provided to the gastrointestinal tract (
Furthermore, the enhanced nutritional parameters reflected by increased levels of Total Protein, Albumin, and Prealbumin in the observation group underscores the effectiveness of EPEN in meeting the elevated metabolic demands following surgery (
The use of visceral proteins such as TP, ALB, and PA as nutritional markers in postoperative patients can be confounded by acute inflammation, which is a well-known limitation in surgical settings. These proteins are often classified as acute-phase reactants and may reflect the inflammatory response rather than an accurate assessment of nutritional parameters. In our study, however, we aimed to minimize these confounding effects to ensure that the observed differences in nutritional markers between the groups were primarily due to the EPEN intervention, rather than surgical factors or acute-phase responses. To address this, we employed several strategies to strengthen the validity of our findings. First, baseline comparability was ensured between the two groups, as the distribution of surgical approaches (laparoscopic vs. open surgery) was similar, reducing the risk of confounding by surgical method. Second, a stratified analysis was performed by surgical approach, and the beneficial effects of EPEN on wound healing time and surgical site infection rates were consistent across both laparoscopic and open surgery subgroups. This suggests that the observed benefits were not influenced by the type of surgery performed. Additionally, to minimize the potential impact of acute inflammation on the nutritional markers, we measured TP, ALB, and PA at baseline (preoperatively) and 14 days post-treatment, rather than in the immediate postoperative period. By this time, the acute inflammatory response typically subsides. Moreover, pre-treatment levels of TP, ALB, and PA were comparable between the two groups, ensuring that the observed changes could not be attributed to baseline differences in inflammatory responses. Finally, the improvements in nutritional markers were closely aligned with clinical outcomes, including shorter wound healing times and lower rates of SSIs in the EPEN group. This consistency between biochemical and clinical results further supports the conclusion that the observed improvements were reflective of true nutritional benefits, rather than the resolution of inflammation. In summary, our study demonstrates that early enteral nutrition can significantly improve both nutritional markers and clinical outcomes, such as wound healing and infection rates, though further research is needed to confirm the role of nutrition in these improvements.
Regarding the influence of acute-phase responses on visceral protein levels, additional inflammatory and immune parameters were collected and analyzed to assess baseline inflammatory status. These included CRP, PCT, white blood cell count, neutrophil and lymphocyte counts, platelet count, and derived indices such as NLR, PLR, and the SII. All parameters were measured within 24 hours before surgery. Comparative analysis revealed no statistically significant differences between the control and observation groups for any of these markers (all P > 0.05), indicating that the two cohorts had comparable baseline inflammatory status. This baseline equivalence reduces the likelihood that differences in postoperative visceral protein indices were attributable to pre-existing disparities in inflammatory activity. While postoperative inflammatory marker trends were not available, the alignment between improved protein indices and favorable clinical outcomes in the EPEN group supports the plausibility that the observed changes are at least partly nutrition-driven rather than solely reflective of inflammation resolution. Nonetheless, we acknowledge that integrating serial postoperative inflammatory marker measurements (e.g., IL-6, TNF-α) and functional nutritional assessments in future prospective studies would strengthen causal inference.
Several limitations should be acknowledged. First, the retrospective nature of the study may introduce biases related to data collection and patient selection. Retrospective analyses often rely on existing records, which might not contain all pertinent variables or detailed patient information. Second, the study’s patient population was drawn from a single institution, which may limit the generalizability of the findings to broader, more diverse populations. Finally, the lack of randomization in group allocation could potentially lead to confounding factors influencing the outcomes. These limitations highlight the need for prospective, randomized controlled trials to further validate and expand upon our findings.
In this retrospective study, the use of EPEN might be associated with improvements in nutritional indicators, such as total protein, albumin, and prealbumin, as well as enhanced clinical outcomes, including shorter wound healing times and reduced surgical site infection rates in patients undergoing gastrointestinal tumor surgery. However, the current data do not provide sufficient evidence to conclusively determine whether the improvements are directly due to EPEN, as factors such as inflammation could also influence these outcomes. Further prospective, randomized studies with additional data on inflammation levels beyond the immediate postoperative period are needed to more thoroughly assess the causal relationships between EPEN and nutritional recovery.
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.
The studies involving humans were approved by the Ethics Committee of The First People's Hospital of Linping District. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.
PW: Data curation, Methodology, Conceptualization, Formal analysis, Investigation, Resources, Software, Writing – review & editing. YD: Writing – review & editing, Supervision, Methodology. FY: Data curation, Methodology, Conceptualization, Formal analysis, Investigation, Resources, Software, Writing – review & editing.
The author(s) declare financial support was received for the research and/or publication of this article. This study was supported by Zhejiang Province Traditional Chinese Medicine Science and Technology Project (Grant No.2025ZL160).
We thank the patients and staff who participated in this study.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
This article has been corrected with minor changes. These changes do not impact the scientific content of the article.
The author(s) declare that no Generative AI was used in the creation of this manuscript.
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